Percutaneous treatment of atrial septal defects, muscular ventricular septal defects and patent ductus arteriosus in infants under one year of age.

Science.gov (United States)

Prada, Fredy; Mortera, Carlos; Bartrons, Joaquim; Rissech, Miguel; Jiménez, Lorenzo; Carretero, Juan; Llevadias, Judit; Araica, Mireya

2009-09-01

Amplatzer devices are used for the percutaneous closure of ostium secundum atrial septal defects, muscular ventricular septal defects and patent ductus arteriosus. However, very little experience has been gained in using these devices in infants under 1 year of age. Between January 2001 and January 2008, 22 symptomatic infants aged under 1 year underwent percutaneous treatment: three had an ostium secundum atrial septal defect, 15 had patent ductus arteriosus, and four had a muscular ventricular septal defect. All the procedures were completed successfully. No immediate or medium-term complications were observed. Closure of these types of defect using an Amplatzer device in infants under 1 year of age, who would otherwise require surgery, is a safe and effective procedure.

The effects of defects on copper melting under hydrostatic and shock loading

Energy Technology Data Exchange (ETDEWEB)

Luo, Shengnian [Los Alamos National Laboratory; An, Qi [Los Alamos National Laboratory; Germann, Timothy C [Los Alamos National Laboratory; Han, Li - Bo [USTC

2009-07-24

With molecular dynamics (MD) simulations, we investigate the effects of defects on Cu melting under hydrostatic and shock wave loading. We explore preexistent defects including vacancies, stacking faults and grain boundaries, as well as shock-induced defects. Depending on defect characteristics (energy and concentration), defects may have negligible or considerable effects on melting at MD scales However, it is expected that defects have more pronounced effects at heating rates lower than the MD rates.

Defect production in Ar irradiated graphene membranes under different initial applied strains

Energy Technology Data Exchange (ETDEWEB)

Martinez-Asencio, J., E-mail: jesusmartinez@ua.es [Dept. Física Aplicada, Facultad de Ciencias, Fase II, Universidad de Alicante, Alicante E-036090 (Spain); Ruestes, C.J.; Bringa, E. [CONICET and Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza 5500 (Argentina); Caturla, M.J. [Dept. Física Aplicada, Facultad de Ciencias, Fase II, Universidad de Alicante, Alicante E-036090 (Spain)

2017-02-15

Highlights: • Defects in graphene membranes are formed due to 140 eV Ar ions irradiation using MD. • Different initial strains are applied, which influence the type and number of defects. • Mono-vacancies, di-vacancies and tri-vacancies production behaves linearly with dose. • The total number of defects under compression is slightly higher than under tension. - Abstract: Irradiation with low energy Ar ions of graphene membranes gives rise to changes in the mechanical properties of this material. These changes have been associated to the production of defects, mostly isolated vacancies. However, the initial state of the graphene membrane can also affect its mechanical response. Using molecular dynamics simulations we have studied defect production in graphene membranes irradiated with 140 eV Ar ions up to a dose of 0.075 × 10{sup 14} ions/cm{sup 2} and different initial strains, from −0.25% (compressive strain) to 0.25% (tensile strain). For all strains, the number of defects increases linearly with dose with a defect production of about 80% (80 defects every 100 ions). Defects are mostly single vacancies and di-vacancies, although some higher order clusters are also observed. Two different types of di-vacancies have been identified, the most common one being two vacancies at first nearest neighbours distance. Differences in the total number of defects with the applied strain are observed which is related to the production of a higher number of di-vacancies under compressive strain compared to tensile strain. We attribute this effect to the larger out-of-plane deformations of compressed samples that could favor the production of defects in closer proximity to others.

Ab initio study of native defects in SnO under strain

KAUST Repository

Bianchi Granato, Danilo

2014-04-01

Tin monoxide (SnO) has promising properties to be applied as a p-type semiconductor in transparent electronics. To this end, it is necessary to understand the behaviour of defects in order to control them. We use density functional theory to study native defects of SnO under tensile and compressive strain. We show that Sn vacancies are less stable under tension and more stable under compression, irrespectively of the charge state. In contrast, O vacancies behave differently for different charge states. It turns out that the most stable defect under compression is the +1 charged O vacancy in an Sn-rich environment and the charge neutral O interstitial in an O-rich environment. Therefore, compression can be used to transform SnO from a p-type into either an n-type or an undoped semiconductor. Copyright © EPLA, 2014.

Targeting a genetic defect: cystic fibrosis transmembrane conductance regulator modulators in cystic fibrosis

Directory of Open Access Journals (Sweden)

Nico Derichs

2013-03-01

Full Text Available Cystic fibrosis (CF is caused by genetic mutations that affect the cystic fibrosis transmembrane conductance regulator (CFTR protein. These mutations can impact the synthesis and transfer of the CFTR protein to the apical membrane of epithelial cells, as well as influencing the gating or conductance of chloride and bicarbonate ions through the channel. CFTR dysfunction results in ionic imbalance of epithelial secretions in several organ systems, such as the pancreas, gastrointestinal tract, liver and the respiratory system. Since discovery of the CFTR gene in 1989, research has focussed on targeting the underlying genetic defect to identify a disease-modifying treatment for CF. Investigated management strategies have included gene therapy and the development of small molecules that target CFTR mutations, known as CFTR modulators. CFTR modulators are typically identified by high-throughput screening assays, followed by preclinical validation using cell culture systems. Recently, one such modulator, the CFTR potentiator ivacaftor, was approved as an oral therapy for CF patients with the G551D-CFTR mutation. The clinical development of ivacaftor not only represents a breakthrough in CF care but also serves as a noteworthy example of personalised medicine.

Ductile failure of pipes with defects under combined pressure and bending

International Nuclear Information System (INIS)

Darlaston, B.J.L.; Harrison, R.P.

1977-01-01

The main part of the experimental programme was carried out on 3.5'' diam. pipes with a wall thickness of 0.064''. Various lengths of defect were assessed but only two depths, 0.044'' and 0.060''. Some full penetration defect tests were carried out under bending loading. The defects were 0.012'' wide and nominally flat bottomed. The tensile properties of the pipes were determined by taking specimens from each of the tubes. The pipes were exposed to pressure only test, bending only test and combined bending and pressure test. The results are given in tables. The observations led to the postulation of a design rule relating to the effect of defect in pipes under combined internal pressure and bending. It applies only to ductile situations in which the mode of failure is by a collapse mechanism: If the failure of a pipe containing an axial defect occurs by plastic collapse then provided the bending moment does not exceed half that for collapse due to bending alone, it will have a negligible effect on the failure pressure. (J.B.)

Genetic interactions between planar cell polarity genes cause diverse neural tube defects in mice

Directory of Open Access Journals (Sweden)

Jennifer N. Murdoch

2014-10-01

Full Text Available Neural tube defects (NTDs are among the commonest and most severe forms of developmental defect, characterized by disruption of the early embryonic events of central nervous system formation. NTDs have long been known to exhibit a strong genetic dependence, yet the identity of the genetic determinants remains largely undiscovered. Initiation of neural tube closure is disrupted in mice homozygous for mutations in planar cell polarity (PCP pathway genes, providing a strong link between NTDs and PCP signaling. Recently, missense gene variants have been identified in PCP genes in humans with NTDs, although the range of phenotypes is greater than in the mouse mutants. In addition, the sequence variants detected in affected humans are heterozygous, and can often be detected in unaffected individuals. It has been suggested that interactions between multiple heterozygous gene mutations cause the NTDs in humans. To determine the phenotypes produced in double heterozygotes, we bred mice with all three pairwise combinations of Vangl2Lp, ScribCrc and Celsr1Crsh mutations, the most intensively studied PCP mutants. The majority of double-mutant embryos had open NTDs, with the range of phenotypes including anencephaly and spina bifida, therefore reflecting the defects observed in humans. Strikingly, even on a uniform genetic background, variability in the penetrance and severity of the mutant phenotypes was observed between the different double-heterozygote combinations. Phenotypically, Celsr1Crsh;Vangl2Lp;ScribCrc triply heterozygous mutants were no more severe than doubly heterozygous or singly homozygous mutants. We propose that some of the variation between double-mutant phenotypes could be attributed to the nature of the protein disruption in each allele: whereas ScribCrc is a null mutant and produces no Scrib protein, Celsr1Crsh and Vangl2Lp homozygotes both express mutant proteins, consistent with dominant effects. The variable outcomes of these genetic

Recurrent candidiasis and early-onset gastric cancer in a patient with a genetically defined partial MYD88 defect.

Science.gov (United States)

Vogelaar, Ingrid P; Ligtenberg, Marjolijn J L; van der Post, Rachel S; de Voer, Richarda M; Kets, C Marleen; Jansen, Trees J G; Jacobs, Liesbeth; Schreibelt, Gerty; de Vries, I Jolanda M; Netea, Mihai G; Hoogerbrugge, Nicoline

2016-04-01

Gastric cancer is caused by both genetic and environmental factors. A woman who suffered from recurrent candidiasis throughout her life developed diffuse-type gastric cancer at the age of 23 years. Using whole-exome sequencing we identified a germline homozygous missense variant in MYD88. Immunological assays on peripheral blood mononuclear cells revealed an impaired immune response upon stimulation with Candida albicans, characterized by a defective production of the cytokine interleukin-17. Our data suggest that a genetic defect in MYD88 results in an impaired immune response and may increase gastric cancer risk.

Computer simulation of defect behavior under fusion irradiation environments

International Nuclear Information System (INIS)

Muroga, T.; Ishino, S.

1983-01-01

To simulate defect behavior under irradiation, three kinds of cascade-annealing calculations have been carried out in alpha-iron using the codes MARLOWE, DAIQUIRI and their modifications. They are (1) cascade-annealing calculation with different masses of projectile, (2) defect drifting near dislocations after cascade production and (3) cascade-overlap calculation. The defect survival ratio is found to increase as decreasing mass of the projectile both after athermal close-pair recombination and after thermal annealing. It is shown that at moderate temperatures vacancy clustering is enhanced near dislocations. Cascade-overlap is found to decrease the defect survivability. In addition, the role of helium in vacancy clustering has been calculated in aluminium lattices and its effect is found to depend strongly on temperature, interstitials and the mobility of small clusters. These results correspond well to the experimental data and will be helpful for correlating between fusion and simulation irradiations. (orig.)

Genetic analysis of metabolic defects in the spontaneously hypertensive rat

Czech Academy of Sciences Publication Activity Database

Pravenec, Michal; Zídek, Václav; Musilová, Alena; Šimáková, Miroslava; Kostka, Vlastimil; Mlejnek, Petr; Křen, Vladimír; Křenová, D.; Bílá, V.; Míková, B.; Jáchymová, M.; Horký, K.; Kazdová, L.; St.Lezin, E.; Kurtz, W. T.

2002-01-01

Roč. 13, č. 5 (2002), s. 253-258 ISSN 0938-8990 R&D Projects: GA MŠk LN00A079; GA ČR GV204/98/K015; GA ČR GA305/00/1646; GA MŠk NB5299 Grant - others:NIH(US) RO1 HL56028; NIH(US) PO1 HL35018; HHMI(US) 55000331 Institutional research plan: CEZ:AV0Z5011922 Keywords : metabolic defects * spontaneously hypertensive rat Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.233, year: 2002

Polymers under ionizing radiation: the study of energy transfers to radiation induced defects

International Nuclear Information System (INIS)

Ventura, A.

2013-01-01

Radiation-induced defects created in polymers submitted to ionizing radiations, under inert atmosphere, present the same trend as a function of the dose. When the absorbed dose increases, their concentrations increase then level off. This behavior can be assigned to energy transfers from the polymer to the previously created macromolecular defects; the latter acting as energy sinks. During this thesis, we aimed to specify the influence of a given defect, namely the trans-vinylene, in the behavior of polyethylene under ionizing radiations. For this purpose, we proposed a new methodology based on the specific insertion, at various concentrations, of trans-vinylene groups in the polyethylene backbone through chemical synthesis. This enables to get rid of the variety of created defects on one hand and on the simultaneity of their creation on the other hand. Modified polyethylenes, containing solely trans-vinylene as odd groups, were irradiated under inert atmosphere, using either low LET beams (gamma, beta) or high LET beams (swift heavy ions). During irradiations, both macromolecular defects and H 2 emission were quantified. According to experimental results, among all defects, the influence of the trans-vinylene on the behavior of polyethylene is predominant. (author) [fr

Auto-oscillations of temperature and defect density in impure crystals under irradiation

International Nuclear Information System (INIS)

Selishchev, P.A.; Sugakov, V.I.

1990-01-01

Appearance of auto-oscillations in temperature and defect density of impurity crystals under irradiation is studied. It is shown that at certain critical parameters stationary distribution of temperature and defect density of the sample irradiated becomes unstable as regards the formation of temporal dissipative structures: auto-oscillations of temperature and defect density. Critical parameters are determined (the rate of defect formation, temperature of crystal environment, etc.) and the frequency of appearing auto-oscillations, its dependence on irradiation conditions and crystal properties are found

Basement Membrane Defects in Genetic Kidney Diseases

Directory of Open Access Journals (Sweden)

Christine Chew

2018-01-01

Full Text Available The glomerular basement membrane (GBM is a specialized structure with a significant role in maintaining the glomerular filtration barrier. This GBM is formed from the fusion of two basement membranes during development and its function in the filtration barrier is achieved by key extracellular matrix components including type IV collagen, laminins, nidogens, and heparan sulfate proteoglycans. The characteristics of specific matrix isoforms such as laminin-521 (α5β2γ1 and the α3α4α5 chain of type IV collagen are essential for the formation of a mature GBM and the restricted tissue distribution of these isoforms makes the GBM a unique structure. Detailed investigation of the GBM has been driven by the identification of inherited abnormalities in matrix proteins and the need to understand pathogenic mechanisms causing severe glomerular disease. A well-described hereditary GBM disease is Alport syndrome, associated with a progressive glomerular disease, hearing loss, and lens defects due to mutations in the genes COL4A3, COL4A4, or COL4A5. Other proteins associated with inherited diseases of the GBM include laminin β2 in Pierson syndrome and LMX1B in nail patella syndrome. The knowledge of these genetic mutations associated with GBM defects has enhanced our understanding of cell–matrix signaling pathways affected in glomerular disease. This review will address current knowledge of GBM-associated abnormalities and related signaling pathways, as well as discussing the advances toward disease-targeted therapies for patients with glomerular disease.

The acceptability among young Hindus and Muslims of actively ending the lives of newborns with genetic defects.

Science.gov (United States)

Kamble, Shanmukh; Ahmed, Ramadan; Sorum, Paul Clay; Mullet, Etienne

2014-03-01

To explore the views in non-Western cultures about ending the lives of damaged newborns. 254 university students from India and 150 from Kuwait rated the acceptability of ending the lives of newborns with genetic defects in 54 vignettes consisting of all combinations of four factors: gestational age (term or 7 months); severity of genetic defect (trisomy 21 alone, trisomy 21 with serious morphological abnormalities or trisomy 13 with impending death); the parents' attitude about prolonging care (unknown, in favour or opposed); and the procedure used (withholding treatment, withdrawing it or injecting a lethal substance). Four clusters were identified by cluster analysis and subjected to analysis of variance. Cluster I, labelled 'Never Acceptable', included 4% of the Indians and 59% of the Kuwaitis. Cluster II, 'No Firm Opinion', had little variation in rating from one scenario to the next; it included 38% of the Indians and 18% of the Kuwaitis. In Cluster III, 'Parents' Attitude+Severity+Procedure', all three factors affected the ratings; it was composed of 18% of the Indians and 16% of the Kuwaitis. Cluster IV was called 'Severity+Parents' Attitude' because these had the strongest impact; it was composed of 40% of the Indians and 7% of the Kuwaitis. In accordance with the teachings of Islam versus Hinduism, Kuwaiti students were more likely to oppose ending a newborn's life under all conditions, Indian students more likely to favour it and to judge its acceptability in light of the different circumstances.

Thermal buckling behavior of defective CNTs under pre-load: A molecular dynamics study.

Science.gov (United States)

Mehralian, Fahimeh; Tadi Beni, Yaghoub; Kiani, Yaser

2017-05-01

Current study is concentrated on the extraordinary properties of defective carbon nanotubes (CNTs). The role of vacancy defects in thermal buckling response of precompressed CNTs is explored via molecular dynamics (MD) simulations. Defective CNTs are initially compressed at a certain ratio of their critical buckling strain and then undergo a uniform temperature rise. Comprehensive study is implemented on both armchair and zigzag CNTs with different vacancy defects including monovacancy, symmetric bivacancy and asymmetric bivacancy. The results reveal that defects have a pronounced impact on the buckling behavior of CNTs; interestingly, defective CNTs under compressive pre-load show higher resistance to thermal buckling than pristine ones. In the following, the buckling response of defective CNTs is shown to be dependent on the vacancy defects, location of defects and chirality. Copyright © 2017 Elsevier Inc. All rights reserved.

Atrioventricular canal defect and associated genetic disorders: new insights into polydactyly syndromes

Directory of Open Access Journals (Sweden)

M. Cristina Digilio

2011-07-01

Full Text Available Atrioventricular canal defect (AVCD is a common congenital heart defect (CHD, representing 7.4% of all cardiac malformations, considered secondary to an extracellular matrix anomaly. The AVCD is associated with extracardiac defects in about 75% of the cases. In this review we analyzed different syndromic AVCDs, in particular those associated with polydactyly disorders, which show remarkable genotype-phenotype correlations. Chromo - some imbalances more frequently associated with AVCD include Down syndrome, deletion 8p23 and deletion 3p25, while mendelian disorders include Noonan syndrome and related RASopathies, several polydactyly syndromes, CHARGE and 3C (cranio-cerebello-cardiac syndrome. The complete form of AVCD is prevalent in patients with chromosomal imbalances. Additional cardiac defects are found in patients affected by chromosomal imbalances different from Down syndrome. Left-sided obstructive lesions are prevalently found in patients with RASopathies. Patients with deletion 8p23 often display AVCD with tetralogy of Fallot or with pulmonary valve stenosis. Tetralogy of Fallot is the only additional cardiac defect found in patients with Down syndrome and AVCD. On the other hand, the association of AVCD and tetralogy of Fallot is also quite characteristic of CHARGE and 3C syndromes. Heterotaxia defects, including common atrium and anomalous pulmonary venous return, occur in patients with AVCD associated with polydactyly syndromes (Ellis-van Creveld, short rib polydactyly, oral-facial-digital, Bardet-Biedl, and Smith-Lemli-Opitz syndromes. The initial clinical evidence of anatomic similarities between AVCD and heterotaxia in polydactyly syndromes was corroborated and explained by experimental studies in transgenic mice. These investigations have suggested the involvement of the Sonic Hedgehog pathway in syndromes with postaxial polydactyly and heterotaxia, and ciliary dysfunction was detected as pathomechanism for these disorders

Vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association with Mayer-Rokitansky-Küster-Hauser syndrome in co-occurrence

DEFF Research Database (Denmark)

Bjørsum-Meyer, Thomas; Herlin, Morten; Qvist, Niels

2016-01-01

Background: The vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association and Mayer-Rokitansky-Küster-Hauser syndrome are rare conditions. We aimed to present two cases with the vertebral defect, anal atresia, cardiac...... defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association and Mayer-Rokitansky-Küster-Hauser co-occurrence from our local surgical center and through a systematic literature search detect published cases. Furthermore, we aimed to collect existing knowledge...... in the embryopathogenesis and genetics in order to discuss a possible link between the vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association and Mayer-Rokitansky-Küster-Hauser syndrome. Case presentation: Our first case was a white girl...

Safety assessment of pipes with multiple local wall thinning defects under pressure and bending moment

International Nuclear Information System (INIS)

Peng Jian; Zhou Changyu; Xue Jilin; Dai Qiao; He Xiaohua

2011-01-01

The safety assessment of pipes with local wall thinning defects is highly important in engineering. Most attention has been paid on the safety assessment of pipe with single local wall thinning defect, while the studies about multiple local wall thinning defects are not nearly enough. However, the interaction of multiple local wall thinning defects in some conditions is great, and may have a great impact on the safety assessment. In the present standard API 579/ASME FFS, the safety assessment of pipes with multiple local wall thinning defects is given, while as well as the influence of load condition, the influences of arrangement and relative depth of defects are ignored, which may influence the safety assessment considerably. In this paper, the influence of the interaction between multiple local wall thinning defects on the remaining strength of pipes at different arrangements and depths of defects under different load conditions (pressure, tension-bending moment and compression-bending moment) are studied. A quantified index is defined to describe the interaction between defects quantitatively. For different arrangements and relative depths of defects, based on a limit value 0.05 of the quantified index of the interaction between defects, a relatively systematic safety assessment of pipes with multiple local wall thinning defects under different load conditions has been proposed.

Molecular marker studies in riverine buffaloes, for characterization and diagnosis of genetic defects

International Nuclear Information System (INIS)

Yadav, B.R.

2005-01-01

The buffalo is probably the last livestock species to have been domesticated, with many genetic, physiological and behavioural traits not yet well understood. Molecular markers have been used for characterizing animals and breeds, diagnosing diseases and identifying anatomical and physiological anomalies. RFLP studies showed low heterozygosity, but genomic and oligonucleotide probes showed species-specific bands useful for identification of carcass or other unknown samples. Use of RAPD revealed band frequencies, band sharing frequencies, genetic distances, and genetic and identity indexes in different breeds. Bovine microsatellite primers indicate that 70.9% of bovine loci were conserved in buffalo. Allele numbers, sizes, frequencies, heterozygosity and polymorphism information content showed breed-specific patterns. Different marker types - genomic and oligonucleotide probes, RAPD and microsatellites - are useful in parent identification. Individual specific DNA fingerprinting techniques were applied with twin-born animal (XX/XY) chimerism, sex identification, anatomically defective and XO individuals. Molecular markers are a potential tool for geneticists and breeders to evaluate existing germplasm and to manipulate it to develop character-specific strains and to provide the basis for effective genetic conservation. (author)

Mechanical properties and fracture behaviour of defective phosphorene nanotubes under uniaxial tension

Science.gov (United States)

Liu, Ping; Pei, Qing-Xiang; Huang, Wei; Zhang, Yong-Wei

2017-12-01

The easy formation of vacancy defects and the asymmetry in the two sublayers of phosphorene nanotubes (PNTs) may result in brand new mechanical properties and failure behaviour. Herein, we investigate the mechanical properties and fracture behaviour of defective PNTs under uniaxial tension using molecular dynamics simulations. Our simulation results show that atomic vacancies cause local stress concentration and thus significantly reduce the fracture strength and fracture strain of PNTs. More specifically, a 1% defect concentration is able to reduce the fracture strength and fracture strain by as much as 50% and 66%, respectively. Interestingly, the reduction in the mechanical properties is found to depend on the defect location: a defect located in the outer sublayer has a stronger effect than one located in the inner layer, especially for PNTs with a small diameter. Temperature is also found to strongly influence the mechanical properties of both defect-free and defective PNTs. When the temperature is increased from 0 K to 400 K, the fracture strength and fracture strain of defective PNTs with a defect concentration of 1% are reduced further by 71% and 61%, respectively. These findings are of great importance for the structural design of PNTs as building blocks in nanodevices.

Schizophrenia with the 22q11.2 deletion and additional genetic defects: case history.

Science.gov (United States)

Toyosima, M; Maekawa, M; Toyota, T; Iwayama, Y; Arai, M; Ichikawa, T; Miyashita, M; Arinami, T; Itokawa, M; Yoshikawa, T

2011-09-01

The 22q11.2 deletion is the most prominent known genetic risk factor for schizophrenia, but its penetrance is at most approximately 50% suggesting that additional risk factors are required for disease progression. We examined a woman with schizophrenia with this deletion for such risk factors. She had high plasma pentosidine levels ('carbonyl stress') and a frameshift mutation in the responsible gene, GLO1. She also had a constant exotropia, so we examined the PHOX2B gene associated with both schizophrenia and strabismus, and detected a 5-alanine deletion. We propose that the combination of these genetic defects may have exceeded the threshold for the manifestation of schizophrenia.

Vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association with Mayer-Rokitansky-Küster-Hauser syndrome in co-occurrence: two case reports and a review of the literature.

Science.gov (United States)

Bjørsum-Meyer, Thomas; Herlin, Morten; Qvist, Niels; Petersen, Michael B

2016-12-21

The vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association and Mayer-Rokitansky-Küster-Hauser syndrome are rare conditions. We aimed to present two cases with the vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association and Mayer-Rokitansky-Küster-Hauser co-occurrence from our local surgical center and through a systematic literature search detect published cases. Furthermore, we aimed to collect existing knowledge in the embryopathogenesis and genetics in order to discuss a possible link between the vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association and Mayer-Rokitansky-Küster-Hauser syndrome. Our first case was a white girl delivered by caesarean section at 37 weeks of gestation; our second case was a white girl born at a gestational age of 40 weeks. A co-occurrence of vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association and Mayer-Rokitansky-Küster-Hauser syndrome was diagnosed in both cases. We performed a systematic literature search in PubMed ((VACTERL) OR (VATER)) AND ((MRKH) OR (Mayer-Rokitansky-Küster-Hauser) OR (mullerian agenesis) OR (mullerian aplasia) OR (MURCS)) without limitations. A similar search was performed in Embase and the Cochrane library. We added two cases from our local center. All cases (n = 9) presented with anal atresia and renal defect. Vertebral defects were present in eight patients. Rectovestibular fistula was confirmed in seven patients. Along with the uterovaginal agenesis, fallopian tube aplasia appeared in five of nine cases and in two cases ovarian involvement also existed. The co-occurrence of the vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal

Structural evolution of defective graphene under heat treatment and gamma irradiation

Science.gov (United States)

Zhang, Yifei; Shi, Jie; Chen, Cheng; Li, Nan; Xu, Zhiwei; Liu, Liangsen; Zhao, Lihuan; Li, Jing; Jing, Miaolei

2018-03-01

We have studied the structural change of defective graphene built by annealing in different temperature under the condition of gamma irradiation. Firstly, we found the heat treatment not only reduced but also striped the graphene. This behavior made defects become more firstly and then become less with the increase of temperature. And then gamma irradiation removed some oxygen-containing groups, by a simultaneous changed over carbon in the graphitic lattice from sp3 to sp2. Also, the gamma irradiation decreased the interlayer spacing between graphene lowest to 3.391 Å and made a crosslink which resulting in the size of the ordered gaining. A variation was detected by Raman spectroscopy that the amorphous carbon was declined after gamma irradiation. Furtherly we found the degree of this decline raised first and then diminished with the increase in the number of defects. The change in repair capacity of gamma irradiation presented a strategy for repairing the defects of graphene.

Genetic Engineering and the Amelioration of Genetic Defect

Science.gov (United States)

Lederberg, Joshua

1970-01-01

Discusses the claims for a brave new world of genetic manipulation" and concludes that if we could agree upon applying genetic (or any other effective) remedies to global problems we probably would need no rescourse to them. Suggests that effective methods of preventing genetic disease are prevention of mutations and detection and…

Genetic and environmental effects on a meat spotting defect in seasoned dry-cured ham

Directory of Open Access Journals (Sweden)

Giulio Pagnacco

2011-01-01

Full Text Available Purpose of this investigation was to determine the nature of a visible spotting defect on the slice of dry-cured ham and assess environmental and genetic causes of this frequent problem. A group of 233 pigs from commercial cross-breeding lines, progeny of ten boars and forty seven sows, was raised in a single herd to obtain the “Italian Heavy Pig”, typically slaughtered at 160 ± 10 kg live weight and older than 9 months of age. A quality evaluation of their right dry-cured hams, seasoned according to the Parma P.D.O. protocol, was undertaken. Each ham was cross-sectioned to obtain a slice of Semimembranosus, Semitendinosus and Biceps Femoris muscles. The focused phenotype was the presence/absence of brownish spots in these muscles, which represent a remarkable meat defect with strong impact on the final sale price. Environmental and management factors were considered in order to evaluate variability related to the phenotype. Animals were raised on two different flooring types (concrete and slatted floor and a Vitamin C diet was also supplemented in the last 45 days before slaughtering to half of the animals. While the pre-planned environmental effects did not show any significant contribution to the total variability of the phenotype, the genetic analysis showed a near to zero value for heritability with a consistent 0.32 repeatability. The proportion of the total phenotypic variance was explained by an important dominance genetic component (0.26 indicating that the technological seasoning process may play a secondary role on the expression of this phenotype.

Defect detection and classification of machined surfaces under multiple illuminant directions

Science.gov (United States)

Liao, Yi; Weng, Xin; Swonger, C. W.; Ni, Jun

2010-08-01

Continuous improvement of product quality is crucial to the successful and competitive automotive manufacturing industry in the 21st century. The presence of surface porosity located on flat machined surfaces such as cylinder heads/blocks and transmission cases may allow leaks of coolant, oil, or combustion gas between critical mating surfaces, thus causing damage to the engine or transmission. Therefore 100% inline inspection plays an important role for improving product quality. Although the techniques of image processing and machine vision have been applied to machined surface inspection and well improved in the past 20 years, in today's automotive industry, surface porosity inspection is still done by skilled humans, which is costly, tedious, time consuming and not capable of reliably detecting small defects. In our study, an automated defect detection and classification system for flat machined surfaces has been designed and constructed. In this paper, the importance of the illuminant direction in a machine vision system was first emphasized and then the surface defect inspection system under multiple directional illuminations was designed and constructed. After that, image processing algorithms were developed to realize 5 types of 2D or 3D surface defects (pore, 2D blemish, residue dirt, scratch, and gouge) detection and classification. The steps of image processing include: (1) image acquisition and contrast enhancement (2) defect segmentation and feature extraction (3) defect classification. An artificial machined surface and an actual automotive part: cylinder head surface were tested and, as a result, microscopic surface defects can be accurately detected and assigned to a surface defect class. The cycle time of this system can be sufficiently fast that implementation of 100% inline inspection is feasible. The field of view of this system is 150mm×225mm and the surfaces larger than the field of view can be stitched together in software.

Study on acoustic emission signals of active defect in pressure piping under hydraulic pressure

International Nuclear Information System (INIS)

Ai Qiong; Liu Caixue; Wang Yao; He Pan; Song Jian

2009-01-01

Experimental investigations of acoustic emission (AE) of active defect in pressure piping with a prefabricated crack under hydraulic pressure tester were conducted. AE signals of fatigue-crack-growth in pressure piping were monitored incessantly in all processes, and all signals recorded were analyzed and processed. The result of signal processing show that the amplitude and energy of acoustic emission signals from defect in pressure pipeline increase gradually with the load time, and thus the active defects in pipeline can be identified; the amplitude, energy and count of acoustic emission signals increase sharply before the defect runs through, and we can forecast the penetrated leakage of pipeline. (authors)

A Hybrid Genetic-Simulated Annealing Algorithm for the Location-Inventory-Routing Problem Considering Returns under E-Supply Chain Environment

Science.gov (United States)

Guo, Hao; Fu, Jing

2013-01-01

Facility location, inventory control, and vehicle routes scheduling are critical and highly related problems in the design of logistics system for e-business. Meanwhile, the return ratio in Internet sales was significantly higher than in the traditional business. Many of returned merchandise have no quality defects, which can reenter sales channels just after a simple repackaging process. Focusing on the existing problem in e-commerce logistics system, we formulate a location-inventory-routing problem model with no quality defects returns. To solve this NP-hard problem, an effective hybrid genetic simulated annealing algorithm (HGSAA) is proposed. Results of numerical examples show that HGSAA outperforms GA on computing time, optimal solution, and computing stability. The proposed model is very useful to help managers make the right decisions under e-supply chain environment. PMID:24489489

A hybrid genetic-simulated annealing algorithm for the location-inventory-routing problem considering returns under e-supply chain environment.

Science.gov (United States)

Li, Yanhui; Guo, Hao; Wang, Lin; Fu, Jing

2013-01-01

Facility location, inventory control, and vehicle routes scheduling are critical and highly related problems in the design of logistics system for e-business. Meanwhile, the return ratio in Internet sales was significantly higher than in the traditional business. Many of returned merchandise have no quality defects, which can reenter sales channels just after a simple repackaging process. Focusing on the existing problem in e-commerce logistics system, we formulate a location-inventory-routing problem model with no quality defects returns. To solve this NP-hard problem, an effective hybrid genetic simulated annealing algorithm (HGSAA) is proposed. Results of numerical examples show that HGSAA outperforms GA on computing time, optimal solution, and computing stability. The proposed model is very useful to help managers make the right decisions under e-supply chain environment.

A Hybrid Genetic-Simulated Annealing Algorithm for the Location-Inventory-Routing Problem Considering Returns under E-Supply Chain Environment

Directory of Open Access Journals (Sweden)

Yanhui Li

2013-01-01

Full Text Available Facility location, inventory control, and vehicle routes scheduling are critical and highly related problems in the design of logistics system for e-business. Meanwhile, the return ratio in Internet sales was significantly higher than in the traditional business. Many of returned merchandise have no quality defects, which can reenter sales channels just after a simple repackaging process. Focusing on the existing problem in e-commerce logistics system, we formulate a location-inventory-routing problem model with no quality defects returns. To solve this NP-hard problem, an effective hybrid genetic simulated annealing algorithm (HGSAA is proposed. Results of numerical examples show that HGSAA outperforms GA on computing time, optimal solution, and computing stability. The proposed model is very useful to help managers make the right decisions under e-supply chain environment.

Using bayesian models to assess the effects of under-reporting of cannabis use on the association with birth defects, national birth defects prevention study, 1997-2005.

Science.gov (United States)

van Gelder, Marleen M H J; Donders, A Rogier T; Devine, Owen; Roeleveld, Nel; Reefhuis, Jennita

2014-09-01

Studies on associations between periconceptional cannabis exposure and birth defects have mainly relied on self-reported exposure. Therefore, the results may be biased due to under-reporting of the exposure. The aim of this study was to quantify the potential effects of this form of exposure misclassification. Using multivariable logistic regression, we re-analysed associations between periconceptional cannabis use and 20 specific birth defects using data from the National Birth Defects Prevention Study from 1997-2005 for 13 859 case infants and 6556 control infants. For seven birth defects, we implemented four Bayesian models based on various assumptions concerning the sensitivity of self-reported cannabis use to estimate odds ratios (ORs), adjusted for confounding and under-reporting of the exposure. We used information on sensitivity of self-reported cannabis use from the literature for prior assumptions. The results unadjusted for under-reporting of the exposure showed an association between cannabis use and anencephaly (posterior OR 1.9 [95% credible interval (CRI) 1.1, 3.2]) which persisted after adjustment for potential exposure misclassification. Initially, no statistically significant associations were observed between cannabis use and the other birth defect categories studied. Although adjustment for under-reporting did not notably change these effect estimates, cannabis use was associated with esophageal atresia (posterior OR 1.7 [95% CRI 1.0, 2.9]), diaphragmatic hernia (posterior OR 1.8 [95% CRI 1.1, 3.0]), and gastroschisis (posterior OR 1.7 [95% CRI 1.2, 2.3]) after correction for exposure misclassification. Under-reporting of the exposure may have obscured some cannabis-birth defect associations in previous studies. However, the resulting bias is likely to be limited. © 2014 John Wiley & Sons Ltd.

[Genetic diagnostics of cancer diseases].

Science.gov (United States)

Cobilanschi, Joana

2013-11-27

Cancer is caused by genetic alterations, but only 10% of the cancer diseases are inherited. The probability for an individual or a family of having inherited cancer, individual consequences of the respective results of genetic testing, as well as its costs and reimbursement by the health insurance must be addressed by expert genetic counseling which at-risk requires special expertise. Identification of a germline mutation which may predispose to a variety of different cancer types allows determination of an individual's specific life time risk in symptomatic as well as in a-symptomatic family members. Identification of the underlying defective gene in heritable cancer disorders also enables optimized preventive and novel therapeutic approaches specifically targeting the underlying molecular pathomechanisms.

Numerical solution of kinetics equation for point defects accumulation in metals under irradiation

International Nuclear Information System (INIS)

Aldzhambekova, G.T.; Iskakov, B.M.

1999-01-01

In the report the mathematical model, describing processes of generation and accumulation of defects in solids under irradiation is considered. The equations of this model take into account the velocity of Frenkel pairs generation, the mutual recombination of vacancies and the interstitials, as well as velocity of defects absorption by discharge channeling of vacancies and interstitials. By Runge-Kutta method the numerical solution of the model was carried out

Congenital Heart Defects (For Parents)

Science.gov (United States)

... to be associated with genetic disorders, such as Down syndrome . But the cause of most congenital heart defects isn't known. While they can't be prevented, many treatments are available for the defects and related health ...

Cancers and genetic defects resulting from the use of various energy sources

International Nuclear Information System (INIS)

Myers, D.K.

1978-06-01

A review of recent literature on carcinogenic effects of chemical products derived from the combustion of organic fuels suggests that the numbers of fatal cancers and genetic defects induced by utilization of fossil fuels may be much greater than the numbers induced by utilization of nuclear power to produce the same amount of energy. Despite the uncertainties involved in these estimates, the maximum risk of fatal cancers due to carcinogenic by-products associated with the production of electricity by any of these methods appears to be remarkably low compared with the risk of other fatal hazards in Canada and the U.S.A. (author)

Intelligence : shared genetic basis between Mendelian disorders and a polygenic trait

NARCIS (Netherlands)

Franić, Sanja; Groen-Blokhuis, Maria M; Dolan, Conor V; Kattenberg, Mathijs V; Pool, René; Xiao, Xiangjun; Scheet, Paul A; Ehli, Erik A; Davies, Gareth E; van der Sluis, Sophie; Abdellaoui, Abdel; Hansell, Narelle K; Martin, Nicholas G; Hudziak, James J; van Beijsterveldt, Catherina E M; Swagerman, Suzanne C; Hulshoff Pol, Hilleke E; de Geus, Eco J C; Bartels, Meike; Ropers, H Hilger; Hottenga, Jouke-Jan; Boomsma, Dorret I

2015-01-01

Multiple inquiries into the genetic etiology of human traits indicated an overlap between genes underlying monogenic disorders (eg, skeletal growth defects) and those affecting continuous variability of related quantitative traits (eg, height). Extending the idea of a shared genetic basis between a

Causal Genetic Variation Underlying Metabolome Differences.

Science.gov (United States)

Swain-Lenz, Devjanee; Nikolskiy, Igor; Cheng, Jiye; Sudarsanam, Priya; Nayler, Darcy; Staller, Max V; Cohen, Barak A

2017-08-01

An ongoing challenge in biology is to predict the phenotypes of individuals from their genotypes. Genetic variants that cause disease often change an individual's total metabolite profile, or metabolome. In light of our extensive knowledge of metabolic pathways, genetic variants that alter the metabolome may help predict novel phenotypes. To link genetic variants to changes in the metabolome, we studied natural variation in the yeast Saccharomyces cerevisiae We used an untargeted mass spectrometry method to identify dozens of metabolite Quantitative Trait Loci (mQTL), genomic regions containing genetic variation that control differences in metabolite levels between individuals. We mapped differences in urea cycle metabolites to genetic variation in specific genes known to regulate amino acid biosynthesis. Our functional assays reveal that genetic variation in two genes, AUA1 and ARG81 , cause the differences in the abundance of several urea cycle metabolites. Based on knowledge of the urea cycle, we predicted and then validated a new phenotype: sensitivity to a particular class of amino acid isomers. Our results are a proof-of-concept that untargeted mass spectrometry can reveal links between natural genetic variants and metabolome diversity. The interpretability of our results demonstrates the promise of using genetic variants underlying natural differences in the metabolome to predict novel phenotypes from genotype. Copyright © 2017 by the Genetics Society of America.

Massively parallel sequencing and targeted exomes in familial kidney disease can diagnose underlying genetic disorders.

Science.gov (United States)

Mallett, Andrew J; McCarthy, Hugh J; Ho, Gladys; Holman, Katherine; Farnsworth, Elizabeth; Patel, Chirag; Fletcher, Jeffery T; Mallawaarachchi, Amali; Quinlan, Catherine; Bennetts, Bruce; Alexander, Stephen I

2017-12-01

Inherited kidney disease encompasses a broad range of disorders, with both multiple genes contributing to specific phenotypes and single gene defects having multiple clinical presentations. Advances in sequencing capacity may allow a genetic diagnosis for familial renal disease, by testing the increasing number of known causative genes. However, there has been limited translation of research findings of causative genes into clinical settings. Here, we report the results of a national accredited diagnostic genetic service for familial renal disease. An expert multidisciplinary team developed a targeted exomic sequencing approach with ten curated multigene panels (207 genes) and variant assessment individualized to the patient's phenotype. A genetic diagnosis (pathogenic genetic variant[s]) was identified in 58 of 135 families referred in two years. The genetic diagnosis rate was similar between families with a pediatric versus adult proband (46% vs 40%), although significant differences were found in certain panels such as atypical hemolytic uremic syndrome (88% vs 17%). High diagnostic rates were found for Alport syndrome (22 of 27) and tubular disorders (8 of 10), whereas the monogenic diagnostic rate for congenital anomalies of the kidney and urinary tract was one of 13. Quality reporting was aided by a strong clinical renal and genetic multidisciplinary committee review. Importantly, for a diagnostic service, few variants of uncertain significance were found with this targeted, phenotype-based approach. Thus, use of targeted massively parallel sequencing approaches in inherited kidney disease has a significant capacity to diagnose the underlying genetic disorder across most renal phenotypes. Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

Efficacy of Rosuvastatin in Children With Homozygous Familial Hypercholesterolemia and Association With Underlying Genetic Mutations

DEFF Research Database (Denmark)

Stein, Evan A; Dann, Eldad J; Wiegman, Albert

2017-01-01

formally evaluated in, or approved for, HoFH children. OBJECTIVES: The authors sought to assess the LDL-C efficacy of rosuvastatin versus placebo in HoFH children, and the relationship with underlying genetic mutations. METHODS: This was a randomized, double-blind, 12-week, crossover study of rosuvastatin...... 20 mg versus placebo, followed by 12 weeks of open-label rosuvastatin. Patients discontinued all lipid-lowering treatment except ezetimibe and/or apheresis. Clinical and laboratory assessments were performed every 6 weeks. The relationship between LDL-C response and genetic mutations was assessed....../dl (range: 130 to 700 mg/dl) on rosuvastatin, producing a mean 85.4 mg/dl (22.3%) difference (p = 0.005). Efficacy was similar regardless of age or use of ezetimibe or apheresis, and was maintained for 12 weeks. Adverse events were few and not serious. Patients with 2 defective versus 2 negative LDL...

Small interstitial clusters as opposite defect recombinators in decomposing solid solutions under irradiation

International Nuclear Information System (INIS)

Orlov, A.N.; Trushin, Yu.V.

1988-01-01

An attempt was made to make allowance for the role of binary and ternary interstitials in the kinetics of radiation point defects both in the presence and in the absence of coherent preseparation. It is shown that in solid solutions, decomposing under irradiation, recombination with binary and ternary interstitials proceeds more quickly than directly, and this difference is more pronounced (from 2 up to 20 time growth) due to defect flow for preseparation at the stage of coherent preseparation formation

Peripheral neuropathy predicts nuclear gene defect in patients with mitochondrial ophthalmoplegia.

Science.gov (United States)

Horga, Alejandro; Pitceathly, Robert D S; Blake, Julian C; Woodward, Catherine E; Zapater, Pedro; Fratter, Carl; Mudanohwo, Ese E; Plant, Gordon T; Houlden, Henry; Sweeney, Mary G; Hanna, Michael G; Reilly, Mary M

2014-12-01

Progressive external ophthalmoplegia is a common clinical feature in mitochondrial disease caused by nuclear DNA defects and single, large-scale mitochondrial DNA deletions and is less frequently associated with point mutations of mitochondrial DNA. Peripheral neuropathy is also a frequent manifestation of mitochondrial disease, although its prevalence and characteristics varies considerably among the different syndromes and genetic aetiologies. Based on clinical observations, we systematically investigated whether the presence of peripheral neuropathy could predict the underlying genetic defect in patients with progressive external ophthalmoplegia. We analysed detailed demographic, clinical and neurophysiological data from 116 patients with genetically-defined mitochondrial disease and progressive external ophthalmoplegia. Seventy-eight patients (67%) had a single mitochondrial DNA deletion, 12 (10%) had a point mutation of mitochondrial DNA and 26 (22%) had mutations in either POLG, C10orf2 or RRM2B, or had multiple mitochondrial DNA deletions in muscle without an identified nuclear gene defect. Seventy-seven patients had neurophysiological studies; of these, 16 patients (21%) had a large-fibre peripheral neuropathy. The prevalence of peripheral neuropathy was significantly lower in patients with a single mitochondrial DNA deletion (2%) as compared to those with a point mutation of mitochondrial DNA or with a nuclear DNA defect (44% and 52%, respectively; Pperipheral neuropathy as the only independent predictor associated with a nuclear DNA defect (P=0.002; odds ratio 8.43, 95% confidence interval 2.24-31.76). Multinomial logistic regression analysis identified peripheral neuropathy, family history and hearing loss as significant predictors of the genotype, and the same three variables showed the highest performance in genotype classification in a decision tree analysis. Of these variables, peripheral neuropathy had the highest specificity (91%), negative

Corrosion Behavior of X80 Steel with Coupled Coating Defects under Alternating Current Interference in Alkaline Environment.

Science.gov (United States)

Li, Zhong; Li, Caiyu; Qian, Hongchang; Li, Jun; Huang, Liang; Du, Cuiwei

2017-06-28

The corrosion behavior of X80 steel in the presence of coupled coating defects was simulated and studied under the interference of alternating current (AC) in an alkaline environment. The results from electrochemical measurements showed that the electrode potential of the coating defect with the smaller exposed area was lower than that with the larger area, which indicated that the steel with the smaller coating defect was more prone to corrosion. The result of weight loss tests also showed that the smaller coating defect had induced a higher corrosion rate. However, the corrosion rate of X80 steel at the larger coating defect decreased gradually with the increase of the larger defect area at a constant smaller defect area. The corrosion morphology images showed that the coating defects with smaller areas suffered from more severe pitting corrosion.

Genetics Home Reference: abdominal wall defect

Science.gov (United States)

... are two main types of abdominal wall defects: omphalocele and gastroschisis . Omphalocele is an opening in the center of the ... covering the exposed organs in gastroschisis. Fetuses with omphalocele may grow slowly before birth (intrauterine growth retardation) ...

Expansion Under Climate Change: The Genetic Consequences.

Science.gov (United States)

Garnier, Jimmy; Lewis, Mark A

2016-11-01

Range expansion and range shifts are crucial population responses to climate change. Genetic consequences are not well understood but are clearly coupled to ecological dynamics that, in turn, are driven by shifting climate conditions. We model a population with a deterministic reaction-diffusion model coupled to a heterogeneous environment that develops in time due to climate change. We decompose the resulting travelling wave solution into neutral genetic components to analyse the spatio-temporal dynamics of its genetic structure. Our analysis shows that range expansions and range shifts under slow climate change preserve genetic diversity. This is because slow climate change creates range boundaries that promote spatial mixing of genetic components. Mathematically, the mixing leads to so-called pushed travelling wave solutions. This mixing phenomenon is not seen in spatially homogeneous environments, where range expansion reduces genetic diversity through gene surfing arising from pulled travelling wave solutions. However, the preservation of diversity is diminished when climate change occurs too quickly. Using diversity indices, we show that fast expansions and range shifts erode genetic diversity more than slow range expansions and range shifts. Our study provides analytical insight into the dynamics of travelling wave solutions in heterogeneous environments.

Asymptotic stability of a genetic network under impulsive control

International Nuclear Information System (INIS)

Li Fangfei; Sun Jitao

2010-01-01

The study of the stability of genetic network is an important motif for the understanding of the living organism at both molecular and cellular levels. In this Letter, we provide a theoretical method for analyzing the asymptotic stability of a genetic network under impulsive control. And the sufficient conditions of its asymptotic stability under impulsive control are obtained. Finally, an example is given to illustrate the effectiveness of the obtained method.

Persistent increase of plasma butyryl/isobutyrylcarnitine concentrations as marker of SCAD defect and ethylmalonic encephalopathy

DEFF Research Database (Denmark)

Merinero, B; Perez-Cerda, C; Ruiz Sala, P

2007-01-01

High concentrations of butyryl/isobutyrylcarnitine (C(4)-carnitine) in plasma with increase of ethylmalonic acid (EMA) in urine point to different genetic entities, and further investigations are required to differentiate the possible underlying defect. Here we report three unrelated cases, two n...

What Are Congenital Heart Defects?

Science.gov (United States)

... a baby with a congenital heart defect. Family history and genetics Congenital heart disease is not usually passed along ... you or your child to a specialist in genetic testing. Cardiac MRI to diagnose a ... Factors to review family history, smoking, and medicines that increase your risk of ...

Weak Defect Identification for Centrifugal Compressor Blade Crack Based on Pressure Sensors and Genetic Algorithm.

Science.gov (United States)

Li, Hongkun; He, Changbo; Malekian, Reza; Li, Zhixiong

2018-04-19

pulsation signal. Genetic algorithm (GA) is used to obtain optimal parameters for this SR system to improve its feature enhancement performance. The analysis result of experimental signal shows the validity of the proposed method for the enhancement and identification of weak defect characteristic. In the end, strain test is carried out to further verify the accuracy and reliability of the analysis result obtained by pressure pulsation signal.

Legal implications of genetics and crime research.

Science.gov (United States)

Denno, D W

1996-01-01

Two controversial topics dominate discussions of the legal implications of genetics and crime research; (1) the viability and politics of such research, which has sparked fervent debate in the USA; and (2) the current status of new or atypical criminal law defences, which would include a genetic-defect defence to criminal behaviour. This chapter begins by examining the scientifically discredited XYY chromosome syndrome defence, the major genetic-defect defence that defendants have attempted, albeit unsuccessfully. It then focuses on attorneys' efforts to test for evidence of genetic abnormality in the recent and highly publicized case involving convicted murderer Stephen Mobley, whose family history reveals four generations of violent, aggressive and behaviourally disordered men and women. Mobley is currently appealing his death sentence before the Georgia Supreme Court on the basis that the trial court denied his request both to have genetic testing performed and to have such testing allowed as evidence into court. This chapter concludes by emphasizing that the question is not whether genetic evidence will ever be admitted into court, but when and under what kinds of circumstances. No doubt, genetic evidence, and comparable kinds of biological evidence, will have a major impact on juries when such evidence is more fully accepted by the legal and scientific communities.

The genetic defect in Cockayne syndrome is associated with a defect in repair of UV-induced DNA damage in transcriptionally active DNA

International Nuclear Information System (INIS)

Venema, J.; Mullenders, L.H.; Natarajan, A.T.; van Zeeland, A.A.; Mayne, L.V.

1990-01-01

Cells from patients with Cockayne syndrome (CS) are hypersensitive to UV-irradiation but have an apparently normal ability to remove pyrimidine dimers from the genome overall. We have measured the repair of pyrimidine dimers in defined DNA sequences in three normal and two CS cell strains. When compared to a nontranscribed locus, transcriptionally active genes were preferentially repaired in all three normal cell strains. There was no significant variation in levels of repair between various normal individuals or between two constitutively expressed genes, indicating that preferential repair may be a consistent feature of constitutively expressed genes in human cells. Neither CS strain, from independent complementation groups, was able to repair transcriptionally active DNA with a similar rate and to the same extent as normal cells, indicating that the genetic defect in CS lies in the pathway for repair of transcriptionally active DNA. These results have implications for understanding the pleiotropic clinical effects associated with disorders having defects in the repair of DNA damage. In particular, neurodegeneration appears to be associated with the loss of preferential repair of active genes and is not simply correlated with reduced levels of overall repair

Nonhomologous recombination between defective poliovirus and coxsackievirus genomes suggests a new model of genetic plasticity for picornaviruses.

Science.gov (United States)

Holmblat, Barbara; Jégouic, Sophie; Muslin, Claire; Blondel, Bruno; Joffret, Marie-Line; Delpeyroux, Francis

2014-08-05

Most of the circulating vaccine-derived polioviruses (cVDPVs) implicated in poliomyelitis outbreaks in Madagascar have been shown to be recombinants between the type 2 poliovirus (PV) strain of the oral polio vaccine (Sabin 2) and another species C human enterovirus (HEV-C), such as type 17 coxsackie A virus (CA17) in particular. We studied intertypic genetic exchanges between PV and non-PV HEV-C by developing a recombination model, making it possible to rescue defective type 2 PV RNA genomes with a short deletion at the 3' end by the cotransfection of cells with defective or infectious CA17 RNAs. We isolated over 200 different PV/CA17 recombinants, using murine cells expressing the human PV receptor (PVR) and selecting viruses with PV capsids. We found some homologous (H) recombinants and, mostly, nonhomologous (NH) recombinants presenting duplications of parental sequences preferentially located in the regions encoding proteins 2A, 2B, and 3A. Short duplications appeared to be stable, whereas longer duplications were excised during passaging in cultured cells or after multiplication in PVR-transgenic mice, generating H recombinants with diverse sites of recombination. This suggests that NH recombination events may be a transient, intermediate step in the generation and selection of the fittest H recombinants. In addition to the classical copy-choice mechanism of recombination thought to generate mostly H recombinants, there may also be a modular mechanism of recombination, involving NH recombinant precursors, shaping the genomes of recombinant enteroviruses and other picornaviruses. Importance: The multiplication of circulating vaccine-derived polioviruses (cVDPVs) in poorly immunized human populations can render these viruses pathogenic, causing poliomyelitis outbreaks. Most cVDPVs are intertypic recombinants between a poliovirus (PV) strain and another human enterovirus, such as type 17 coxsackie A viruses (CA17). For further studies of the genetic exchanges

An ultrastructural and immunocytochemical study of a rare genetic sperm tail defect that causes infertility in humans.

Science.gov (United States)

Baccetti, Baccio; Bruni, Emanuele; Gambera, Laura; Moretti, Elena; Piomboni, Paola

2004-08-01

To characterize and describe the ontogenesis of a rare flagellar defect affecting the whole sperm population of a sterile man. Case report. Regional referral center for male infertility in Siena, Italy. A 28-year-old man with severe asthenozoospermia. Physical and hormonal assays, semen analysis, and testicular biopsy. Semen samples and testicular biopsies were analyzed by light and transmission electron microscopy; immunocytochemical study with anti-beta-tubulin and anti-AKAP 82 antibodies was performed to detect the presence and distribution of proteins. Ultrastructural analysis of ejaculated spermatozoa and testicular biopsy revealed absence of the fibrous sheath in the principal-piece region of the tail. Fibrous sheath-like structures were observed in cytoplasmic residues and residual bodies released by spermatids in the seminiferous epithelium. Other anomalies observed were supplementary axonemes and mitochondrial helix elongation. These features were confirmed by immunocytochemical staining. This rare sperm tail defect, characterized by absence of the fibrous sheath, presence of supplementary axonemes, and an abnormally elongated midpiece, originates in the seminiferous tubules during spermiogenesis, as detected in testicular biopsy sections. These defects occur in the whole sperm population, and therefore a genetic origin could be suggested.

Public health approach to birth defects: the Argentine experience.

Science.gov (United States)

Bidondo, María Paz; Groisman, Boris; Barbero, Pablo; Liascovich, Rosa

2015-04-01

Birth defects are a global problem, but their impact is particularly severe in low and middle income countries, where the conditions for prevention, treatment, and rehabilitation are more critical. The epidemiological transition in the infant mortality causes, and the concern of the community and the mass media about the teratogenic risk of environmental pollutants, has made health authorities aware of the importance of birth defects in Argentina. The objective of this paper is to outline those actions specifically taken in Argentina aimed at the prevention of birth defects at a national level. Firstly, we focus on birth defects in Argentina on a general basis, and then we present different laws and actions taken in terms of surveillance and public health programs, primary, secondary, and tertiary prevention. Finally, we present the Teratology Information Service "Fetal Health Line", and the genetic services organization and health professionals training by the National Center of Medical Genetics and the National Program of Genetics Network. In conclusion, in the country, several programs focus on different approaches to the problem, and the challenge is to coordinate the teamwork between them. Finally, we list tips to address birth defects from the public health perspective.

Rapid and reliable healing of critical size bone defects with genetically modified sheep muscle.

Science.gov (United States)

Liu, F; Ferreira, E; Porter, R M; Glatt, V; Schinhan, M; Shen, Z; Randolph, M A; Kirker-Head, C A; Wehling, C; Vrahas, M S; Evans, C H; Wells, J W

2015-09-21

Large segmental defects in bone fail to heal and remain a clinical problem. Muscle is highly osteogenic, and preliminary data suggest that autologous muscle tissue expressing bone morphogenetic protein-2 (BMP-2) efficiently heals critical size defects in rats. Translation into possible human clinical trials requires, inter alia, demonstration of efficacy in a large animal, such as the sheep. Scale-up is fraught with numerous biological, anatomical, mechanical and structural variables, which cannot be addressed systematically because of cost and other practical issues. For this reason, we developed a translational model enabling us to isolate the biological question of whether sheep muscle, transduced with adenovirus expressing BMP-2, could heal critical size defects in vivo. Initial experiments in athymic rats noted strong healing in only about one-third of animals because of unexpected immune responses to sheep antigens. For this reason, subsequent experiments were performed with Fischer rats under transient immunosuppression. Such experiments confirmed remarkably rapid and reliable healing of the defects in all rats, with bridging by 2 weeks and remodelling as early as 3-4 weeks, despite BMP-2 production only in nanogram quantities and persisting for only 1-3 weeks. By 8 weeks the healed defects contained well-organised new bone with advanced neo-cortication and abundant marrow. Bone mineral content and mechanical strength were close to normal values. These data demonstrate the utility of this model when adapting this technology for bone healing in sheep, as a prelude to human clinical trials.

Behavior of defective LWR-type fuel rods irradiated under postulated accident conditions

International Nuclear Information System (INIS)

Hobbins, R.R.; Croucher, D.W.; Seiffert, S.L.; Cook, B.A.; Kerwin, D.K.; Mehner, A.S.; Ploger, S.A.

1979-05-01

The irradiation experiments reported here have been conducted by the Thermal Fuels Behavior Program of EG and G Idaho, Inc., for the United States Nuclear Regulatory Commission in the Power Burst Facility (PBF) at the Idaho National Engineering Laboratory. Five of the rods were irradiated in PCM tests and one in a LOC test. During these tests, the six rods lost cladding integrity prior to or during the transient phase of the test due to either manufacturing defects or intentional rod design and operation. Of the five defective rods tested under PCM conditions, one (Rod IE-008, Test IE-1) had a hydride rupture below the region of the rod, which was in film boiling during the transient; two (Rod A-0021, Test PCM-3 and Rod IE-019, Test IE-5) contained defects (a pin hole and a small axial crack, respectively) within the film boiling zone; and two (Rod 201-1, Test PCM-1 and Rod 205-8, Test PCM-5) failed by cladding embrittlement within the film boiling zone. Rod 312-3 was waterlogged before being subjected to LOC conditions in Test LLR-3

Radiation induced deep level defects in bipolar junction transistors under various bias conditions

International Nuclear Information System (INIS)

Liu, Chaoming; Yang, Jianqun; Li, Xingji; Ma, Guoliang; Xiao, Liyi; Bollmann, Joachim

2015-01-01

Bipolar junction transistor (BJT) is sensitive to ionization and displacement radiation effects in space. In this paper, 35 MeV Si ions were used as irradiation source to research the radiation damage on NPN and PNP bipolar transistors. The changing of electrical parameters of transistors was in situ measured with increasing irradiation fluence of 35 MeV Si ions. Using deep level transient spectroscopy (DLTS), defects in the bipolar junction transistors under various bias conditions are measured after irradiation. Based on the in situ electrical measurement and DLTS spectra, it is clearly that the bias conditions can affect the concentration of deep level defects, and the radiation damage induced by heavy ions.

Behavior of high Tc-superconductors and irradiated defects under reactor irradiation

International Nuclear Information System (INIS)

Atobe, Kozo; Honda, Makoto; Fukuoka, Noboru; Yoshida, Hiroyuki.

1991-01-01

It has been well known that the lattice defects of various types are introduced in ceramics without exception, and exert large effect to the function of these materials. Among oxides, the electronic materials positively using oxygen defect control have been already put in practical use. Also in the oxide high temperature superconductors which are Perovskite type composite oxides, the superconductive characteristics are affected largely by the concentration of the oxygen composing them. This is regarded as an important factor for causing superconductivity, related with the oxygen cavities arising at this time and the carriers bearing superconductivity. In this study, the irradiation effect with relatively low dose, the measurement under irradiation, the effect of irradiation temperature, and the effect of radiation quality were evaluated by the irradiation of YBCO, EBCO and LBCO. The experimental method, and the irradiation effect at low temperature and normal temperature, the effect of Co-60 gamma ray irradiation instead of reactor irradiation are reported. (K.I.)

Iridoschisis: high frequency ultrasound imaging. Evidence for a genetic defect?

Science.gov (United States)

Danias, J; Aslanides, I M; Eichenbaum, J W; Silverman, R H; Reinstein, D Z; Coleman, D J

1996-01-01

AIMS: To elucidate changes in the anatomy of the anterior chamber associated with iridoschisis, a rare form of iris atrophy, and their potential contribution to angle closure glaucoma. METHODS: Both eyes of a 71-year-old woman with bilateral iridoschisis and fibrous dysplasia and her asymptomatic 50-year-old daughter were scanned with a very high frequency (50 MHz) ultrasound system. RESULTS: The symptomatic patient exhibited diffuse changes in the iris stoma with an intact posterior iris pigmented layer in both eyes. These changes were clinically compatible with the lack of iris transillumination defects. Additionally, iris bowing with a resultant narrowing of the angle occurred. The asymptomatic daughter showed discrete, but less severe iris stromal changes. CONCLUSION: This is the first detailed study of high frequency ultrasonic imaging of the iris in iridoschisis. The observed structural changes suggest angle narrowing by forward bowing of the anterior iris stroma may be a mechanism of IOP elevation in this condition. The ultrasonic detection of iris changes in the asymptomatic daughter of the symptomatic patient and the association of iridoschisis with fibrous dysplasia suggest a possible genetic component in the pathogenesis of this condition. Images PMID:9059271

Systematic Analysis of the DNA Damage Response Network in Telomere Defective Budding Yeast

Directory of Open Access Journals (Sweden)

Eva-Maria Holstein

2017-07-01

Full Text Available Functional telomeres are critically important to eukaryotic genetic stability. Scores of proteins and pathways are known to affect telomere function. Here, we report a series of related genome-wide genetic interaction screens performed on budding yeast cells with acute or chronic telomere defects. Genetic interactions were examined in cells defective in Cdc13 and Stn1, affecting two components of CST, a single stranded DNA (ssDNA binding complex that binds telomeric DNA. For comparison, genetic interactions were also examined in cells with defects in Rfa3, affecting the major ssDNA binding protein, RPA, which has overlapping functions with CST at telomeres. In more complex experiments, genetic interactions were measured in cells lacking EXO1 or RAD9, affecting different aspects of the DNA damage response, and containing a cdc13-1 induced telomere defect. Comparing fitness profiles across these data sets helps build a picture of the specific responses to different types of dysfunctional telomeres. The experiments show that each context reveals different genetic interactions, consistent with the idea that each genetic defect causes distinct molecular defects. To help others engage with the large volumes of data, the data are made available via two interactive web-based tools: Profilyzer and DIXY. One particularly striking genetic interaction observed was that the chk1∆ mutation improved fitness of cdc13-1 exo1∆ cells more than other checkpoint mutations (ddc1∆, rad9∆, rad17∆, and rad24∆, whereas, in cdc13-1 cells, the effects of all checkpoint mutations were similar. We show that this can be explained by Chk1 stimulating resection—a new function for Chk1 in the eukaryotic DNA damage response network.

Influence of preliminary reactor irradiation on defect formation in quartz fibers under γ- ray activity

International Nuclear Information System (INIS)

Ashurov, M.Kh.; Baydjanov, M.I.; Ibragimov, J.D.; Rustamov, I.R.; Islamov, A.Kh.; Nuritdinov, I.; Gasanov, E.M.; Yuldashev, B.S.

2006-01-01

Full text: For study of influence of preliminary structure defects and type of cladding material on additional defects accumulation kinetics we investigated the absorption spectra of optical fibers (OF) marked FVP-400 (quartz core and quartz clad) and FSHA-800 (quartz core and polymeric clad) preliminary irradiated by fast neutrons fluencies 10 12 , 10 13 , 10 14 , 10 15 cm -2 before and after additional irradiation by γ-rays of 60 Co source. Preliminary irradiation of samples was conducted in cadmium-plated channel of the reactor. Dose rate of accompanying γ-radiation is determined as 1250 R/s using KI quartz glass based dosimeter. The spectra of the induced absorption (losses) were calculated by an expression A(λ)=(10/L)x lg[T(λ)/T 0 (λ)], where T 0 (λ) and (λ) are transmissions of samples before and after irradiation, L-sample length [m], A(λ)- optical losses [dB/m]. It's established that the transformation processes of previously existing structure damages arising during fiber drawing into other ones and creations of additional defects under influence of neutrons depends on hydroxyl content and type of fibers cladding material. It's shown that under influence of γ-rays at doses 10 5 , 5·10 5 , 10 6 , 5.10 6 , 10 7 , 5·10 7 and 10 8 R the two-stage accumulation of non-bridging oxygen hole centers (NBOHC) is observed in preliminary neutron-irradiated OF. The first stage is caused by appearance of potential NBOHC arising during fiber drawing and irradiation of OF by neutrons. The dose value of γ-rays at the beginning of the second stage that is connected to creation of additional NBOHC under γ-rays action decreases with growth of preliminary irradiation fluence. We suppose that under neutron irradiation of OF along with transformation of previously existing damages and creation of additional point defects there is formation of areas with the higher density than in quartz glass which concentration increases with growth of irradiation fluence. Hence

Blood flow patterns underlie developmental heart defects.

Science.gov (United States)

Midgett, Madeline; Thornburg, Kent; Rugonyi, Sandra

2017-03-01

Although cardiac malformations at birth are typically associated with genetic anomalies, blood flow dynamics also play a crucial role in heart formation. However, the relationship between blood flow patterns in the early embryo and later cardiovascular malformation has not been determined. We used the chicken embryo model to quantify the extent to which anomalous blood flow patterns predict cardiac defects that resemble those in humans and found that restricting either the inflow to the heart or the outflow led to reproducible abnormalities with a dose-response type relationship between blood flow stimuli and the expression of cardiac phenotypes. Constricting the outflow tract by 10-35% led predominantly to ventricular septal defects, whereas constricting by 35-60% most often led to double outlet right ventricle. Ligation of the vitelline vein caused mostly pharyngeal arch artery malformations. We show that both cardiac inflow reduction and graded outflow constriction strongly influence the development of specific and persistent abnormal cardiac structure and function. Moreover, the hemodynamic-associated cardiac defects recapitulate those caused by genetic disorders. Thus our data demonstrate the importance of investigating embryonic blood flow conditions to understand the root causes of congenital heart disease as a prerequisite to future prevention and treatment. NEW & NOTEWORTHY Congenital heart defects result from genetic anomalies, teratogen exposure, and altered blood flow during embryonic development. We show here a novel "dose-response" type relationship between the level of blood flow alteration and manifestation of specific cardiac phenotypes. We speculate that abnormal blood flow may frequently underlie congenital heart defects. Copyright © 2017 the American Physiological Society.

Growth Defects in the Dorsal Pallium after Genetically Targeted Ablation of Principal Preplate Neurons and Neuroblasts: A Morphometric Analysis

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Robin Fisher

2010-09-01

Full Text Available The present study delineates the large-scale, organic responses of growth in the dorsal pallium to targeted genetic ablations of the principal PP (preplate neurons of the neocortex. Ganciclovir treatment during prenatal development [from E11 (embryonic age 11 to E13] of mice selectively killed cells with shared S-phase vulnerability and targeted expression of a GPT [golli promoter transgene; GPT linked to HSV-TK (herpes simplex virus-thymidine kinase, τ-eGFP and lacZ reporters] localized in PP neurons and their intermediate progenitor neuroblasts. The volume, area and thickness of the pallium were measured in an E12-P4 (postnatal age 4 longitudinal study with comparisons between ablated (HSV-TK+/0 and control (HSV-TK0/0 littermates. The extent of ablations was also systematically varied, and the effect on physical growth was assessed in an E18 cross-sectional study. The morphological evidence obtained in the present study supports the conclusion that genetically targeted ablations delay the settlement of the principal PP neurons of the dorsal pallium. This leads to progressive and substantial reductions of growth, despite compensatory responses that rapidly replace the ablated cells. These growth defects originate from inductive cellular interactions in the proliferative matrix of the ventricular zone of the pallium, but are amplified by subsequent morphogenic and trophic cellular interactions. The defects persist during the course of prenatal and postnatal development to demonstrate a constrained dose-response relationship with the extent of specific killing of GPT neurons. The defects propagate simultaneously in both the horizontal and vertical cytoarchitectural dimensions of the developing pallium, an outcome that produces a localized shortfall of volume in the telencephalic vesicles.

Genetic Variant in Flavin-Containing Monooxygenase 3 Alters Lipid Metabolism in Laying Hens in a Diet-Specific Manner

OpenAIRE

Wang, Jing; Long, Cheng; Zhang, Haijun; Zhang, Yanan; Wang, Hao; Yue, Hongyuan; Wang, Xiaocui; Wu, Shugeng; Qi, Guanghai

2016-01-01

Genetic variant T329S in flavin-containing monooxygenase 3 (FMO3) impairs trimethylamine (TMA) metabolism in birds. The TMA metabolism that under complex genetic and dietary regulation, closely linked to cardiovascular disease risk. We determined whether the genetic defects in TMA metabolism may change other metabolic traits in birds, determined whether the genetic effects depend on diets, and to identify genes or gene pathways that underlie the metabolic alteration induced by genetic and die...

Maternal-Zygotic Epistasis and the Evolution of Genetic Diseases

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Nicholas K. Priest

2010-01-01

Full Text Available Many birth defects and genetic diseases are expressed in individuals that do not carry the disease causing alleles. Genetic diseases observed in offspring can be caused by gene expression in mothers and by interactions between gene expression in mothers and offspring. It is not clear whether the underlying pattern of gene expression (maternal versus offspring affects the incidence of genetic disease. Here we develop a 2-locus population genetic model with epistatic interactions between a maternal gene and a zygotic gene to address this question. We show that maternal effect genes that affect disease susceptibility in offspring persist longer and at higher frequencies in a population than offspring genes with the same effects. We find that specific forms of maternal-zygotic epistasis can maintain disease causing alleles at high frequencies over a range of plausible values. Our findings suggest that the strength and form of epistasis and the underlying pattern of gene expression may greatly influence the prevalence of human genetic diseases.

Inositol- and folate-resistant neural tube defects in mice lacking the epithelial-specific factor Grhl-3.

Science.gov (United States)

Ting, Stephen B; Wilanowski, Tomasz; Auden, Alana; Hall, Mark; Voss, Anne K; Thomas, Tim; Parekh, Vishwas; Cunningham, John M; Jane, Stephen M

2003-12-01

The neural tube defects (NTDs) spina bifida and anencephaly are widely prevalent severe birth defects. The mouse mutant curly tail (ct/ct) has served as a model of NTDs for 50 years, even though the responsible genetic defect remained unrecognized. Here we show by gene targeting, mapping and genetic complementation studies that a mouse homolog of the Drosophila grainyhead (grh) gene, grainyhead-like-3 (Grhl3), is a compelling candidate for the gene underlying the curly tail phenotype. The NTDs in Grhl3-null mice are more severe than those in the curly tail strain, as the Grhl3 alleles in ct/ct mice are hypomorphic. Spina bifida in ct/ct mice is folate resistant, but its incidence can be markedly reduced by maternal inositol supplementation periconceptually. The NTDs in Grhl3-/- embryos are also folate resistant, but unlike those in ct/ct mice, they are resistant to inositol. These findings suggest that residual Grhl3 expression in ct/ct mice may be required for inositol rescue of folate-resistant NTDs.

Transformation of point defects under annealing of neutron-irradiated Si and Si:Ge

International Nuclear Information System (INIS)

Pomozov, Yu.V.; Khirunenko, L.I.; Shakhovtsev, V.I.; Yashnik, V.I.

1990-01-01

Transformation of point radiation defects under isochronous annealing of neurton-irradaited Si and Si:Ge is studied. It is determined, that occurence of several new centers which produce A-centre range absorption bands is observed at annealing within 423-493 K temperature range. It is shown that vacancy and oxygen are included in the centers composition. It is found that VO centre transformation into VO 2 at annealing occurs via intermediate stage in contrast to that occuring in electron-irradiated crystals via VO direct diffusion to interstitial oxygen. Transformation of centers under Si ansd Si:Ge annealing occurs similarly

Congenital heart defects in Williams syndrome.

Science.gov (United States)

Yuan, Shi-Min

2017-01-01

Yuan SM. Congenital heart defects in Williams syndrome. Turk J Pediatr 2017; 59: 225-232. Williams syndrome (WS), also known as Williams-Beuren syndrome, is a rare genetic disorder involving multiple systems including the circulatory system. However, the etiologies of the associated congenital heart defects in WS patients have not been sufficiently elucidated and represent therapeutic challenges. The typical congenital heart defects in WS were supravalvar aortic stenosis, pulmonary stenosis (both valvular and peripheral), aortic coarctation and mitral valvar prolapse. The atypical cardiovascular anomalies include tetralogy of Fallot, atrial septal defects, aortic and mitral valvular insufficiencies, bicuspid aortic valves, ventricular septal defects, total anomalous pulmonary venous return, double chambered right ventricle, Ebstein anomaly and arterial anomalies. Deletion of the elastin gene on chromosome 7q11.23 leads to deficiency or abnormal deposition of elastin during cardiovascular development, thereby leading to widespread cardiovascular abnormalities in WS. In this article, the distribution, treatment and surgical outcomes of typical and atypical cardiac defects in WS are discussed.

Photographic guide of selected external defect indicators and associated internal defects in sugar maple

Science.gov (United States)

Everette D. Rast; John A. Beaton; David L. Sonderman

1991-01-01

To properly classify or grade logs or trees, one must be able to correctly identify defect indicators and assess the effect of the underlying defect on possible end products. This guide assists the individual in identifying the surface defect indicator and shows the progressive stages of the defect throughout its development for sugar maple. Eleven types of external...

Photographic guide of selected external defect indicators and associated internal defects in yellow-poplar

Science.gov (United States)

Everette D. Rast; John A. Beaton; David L. Sonderman

1991-01-01

To properly classify or grade logs or trees, one must be able to correctly identify defect indicators and assess the effect of the underlying defect on possible end products. This guide assists the individual in identifying the surface defect indicator and shows the progressive stages of the defect throughout its development for yellow-poplar. Twelve types of external...

Photographic guide of selected external defect indicators and associated internal defects in yellow birch

Science.gov (United States)

Everette D. Rast; John A. Beaton; David L. Sonderman

1991-01-01

To properly classify or grade logs or trees, one must be able to correctly identify defect indicators and assess the effect of the underlying defect on possible end products. This guide assists the individual in identifying the surface defect indicator and shows the progressive stages of the defect throughout its development for yellow birch. Eleven types of external...

Genetic architecture underlying convergent evolution of egg-laying behavior in a seed-feeding beetle.

Science.gov (United States)

Fox, Charles W; Wagner, James D; Cline, Sara; Thomas, Frances Ann; Messina, Frank J

2009-05-01

Independent populations subjected to similar environments often exhibit convergent evolution. An unresolved question is the frequency with which such convergence reflects parallel genetic mechanisms. We examined the convergent evolution of egg-laying behavior in the seed-feeding beetle Callosobruchus maculatus. Females avoid ovipositing on seeds bearing conspecific eggs, but the degree of host discrimination varies among geographic populations. In a previous experiment, replicate lines switched from a small host to a large one evolved reduced discrimination after 40 generations. We used line crosses to determine the genetic architecture underlying this rapid response. The most parsimonious genetic models included dominance and/or epistasis for all crosses. The genetic architecture underlying reduced discrimination in two lines was not significantly different from the architecture underlying differences between geographic populations, but the architecture underlying the divergence of a third line differed from all others. We conclude that convergence of this complex trait may in some cases involve parallel genetic mechanisms.

Syndromes and Disorders Associated with Omphalocele (III: Single Gene Disorders, Neural Tube Defects, Diaphragmatic Defects and Others

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Chih-Ping Chen

2007-06-01

Full Text Available Omphalocele can be associated with single gene disorders, neural tube defects, diaphragmatic defects, fetal valproate syndrome, and syndromes of unknown etiology. This article provides a comprehensive review of omphalocele-related disorders: otopalatodigital syndrome type II; Melnick–Needles syndrome; Rieger syndrome; neural tube defects; Meckel syndrome; Shprintzen–Goldberg omphalocele syndrome; lethal omphalocele-cleft palate syndrome; cerebro-costo-mandibular syndrome; fetal valproate syndrome; Marshall–Smith syndrome; fibrochondrogenesis; hydrolethalus syndrome; Fryns syndrome; omphalocele, diaphragmatic defects, radial anomalies and various internal malformations; diaphragmatic defects, limb deficiencies and ossification defects of skull; Donnai–Barrow syndrome; CHARGE syndrome; Goltz syndrome; Carpenter syndrome; Toriello–Carey syndrome; familial omphalocele; Cornelia de Lange syndrome; C syndrome; Elejalde syndrome; Malpuech syndrome; cervical ribs, Sprengel anomaly, anal atresia and urethral obstruction; hydrocephalus with associated malformations; Kennerknecht syndrome; lymphedema, atrial septal defect and facial changes; and craniosynostosis- mental retardation syndrome of Lin and Gettig. Perinatal identification of omphalocele should alert one to the possibility of omphalocele-related disorders and familial inheritance and prompt a thorough genetic counseling for these disorders.

Effect of vacancy defect on electrical properties of chiral single-walled carbon nanotube under external electrical field

International Nuclear Information System (INIS)

Luo Yu-Pin; Tien Li-Gan; Tsai Chuen-Horng; Lee Ming-Hsien; Li Feng-Yin

2011-01-01

Ab initio calculations demonstrated that the energy gap modulation of a chiral carbon nanotube with mono-vacancy defect can be achieved by applying a transverse electric field. The bandstructure of this defective carbon nanotube varying due to the external electric field is distinctly different from those of the perfect nanotube and defective zigzag nanotube. This variation in bandstructure strongly depends on not only the chirality of the nanotube and also the applied direction of the transverse electric field. A mechanism is proposed to explain the response of the local energy gap between the valence band maximum state and the local gap state under external electric field. Several potential applications of these phenomena are discussed. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

On holographic defect entropy

International Nuclear Information System (INIS)

Estes, John; Jensen, Kristan; O’Bannon, Andy; Tsatis, Efstratios; Wrase, Timm

2014-01-01

We study a number of (3+1)- and (2+1)-dimensional defect and boundary conformal field theories holographically dual to supergravity theories. In all cases the defects or boundaries are planar, and the defects are codimension-one. Using holography, we compute the entanglement entropy of a (hemi-)spherical region centered on the defect (boundary). We define defect and boundary entropies from the entanglement entropy by an appropriate background subtraction. For some (3+1)-dimensional theories we find evidence that the defect/boundary entropy changes monotonically under certain renormalization group flows triggered by operators localized at the defect or boundary. This provides evidence that the g-theorem of (1+1)-dimensional field theories generalizes to higher dimensions

Genetic Syndromes Associated with Congenital Cardiac Defects and Ophthalmologic Changes - Systematization for Diagnosis in the Clinical Practice.

Science.gov (United States)

Oliveira, Priscila H A; Souza, Beatriz S; Pacheco, Eimi N; Menegazzo, Michele S; Corrêa, Ivan S; Zen, Paulo R G; Rosa, Rafael F M; Cesa, Claudia C; Pellanda, Lucia C; Vilela, Manuel A P

2018-01-01

Numerous genetic syndromes associated with heart disease and ocular manifestations have been described. However, a compilation and a summarization of these syndromes for better consultation and comparison have not been performed yet. The objective of this work is to systematize available evidence in the literature on different syndromes that may cause congenital heart diseases associated with ocular changes, focusing on the types of anatomical and functional changes. A systematic search was performed on Medline electronic databases (PubMed, Embase, Cochrane, Lilacs) of articles published until January 2016. Eligibility criteria were case reports or review articles that evaluated the association of ophthalmic and cardiac abnormalities in genetic syndrome patients younger than 18 years. The most frequent genetic syndromes were: Down Syndrome, Velo-cardio-facial / DiGeorge Syndrome, Charge Syndrome and Noonan Syndrome. The most associated cardiac malformations with ocular findings were interatrial communication (77.4%), interventricular communication (51.6%), patent ductus arteriosus (35.4%), pulmonary artery stenosis (25.8%) and tetralogy of Fallot (22.5%). Due to their clinical variability, congenital cardiac malformations may progress asymptomatically to heart defects associated with high morbidity and mortality. For this reason, the identification of extra-cardiac characteristics that may somehow contribute to the diagnosis of the disease or reveal its severity is of great relevance.

Reproduction, Smell and Neurodevelopmental disorders: Genetic defects in different hypogonadotropic hypogonadal syndromes.

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Hernan G VALDES-SOCIN

2014-07-01

Full Text Available The neuroendocrine control of reproduction in mammals is governed by a neural hypothalamic network of nearly 1500 gonadotropin-releasing hormone (GnRH secreting neurons that modulate the activity of the reproductive axis across life. Congenital hypogonadotropic hypogonadism (HH is a clinical syndrome that is characterized by partial or complete pubertal failure. HH may result from inadequate hypothalamic GnRH axis activation, or a failure of pituitary gonadotropin secretion/effects. In man, several genes that participate in olfactory and GnRH neuronal migration are thought to interact during the embryonic life. A growing number of mutations in different genes are responsible for congenital HH. Based on the presence or absence of olfaction dysfunction, HH is divided in two syndromes: HH with olfactory alterations (Kallmann syndrome and idiopathic hypogonadotropic hypogonadism (IHH with normal smell (normosmic IHH. Kallmann syndrome (KS is a heterogeneous disorder affecting 1 in 5000 males, with a 3-5 fold of males over females. KS is associated with mutations in KAL1, FGFR1/FGF8, FGF17, IL17RD, PROK2/PROKR2, NELF, CHD7, HS6ST1, FLRT3, SPRY4, DUSP6, SEMA3A, NELF and WDR11 genes that are related to defects in neuronal migration. These reproductive and olfactory deficits include a variable non reproductive phenotype, including sensorineural deafness, coloboma, bimanual synkinesis, craniofacial abnormalities and/or renal agenesis. Interestingly, defects in PROKR2, FGFR1, FGF8, CHD7, DUSP6, and WDR11 genes are also associated with normosmic IHH, whereas mutations in KISS1/KISSR, TAC3/TACR3, GNRH1/GNRHR, LEP/LEPR, HESX1, FSHB and LHB are only present in patients with normosmic IHH. In this paper, we summarize the reproductive, neurodevelopmental and genetic aspects of HH in human pathology.

Dynamics of defect-loaded grain boundary under shear deformation in alpha iron

Science.gov (United States)

Yang, L.; Zhou, H. L.; Liu, H.; Gao, F.; Zu, X. T.; Peng, S. M.; Long, X. G.; Zhou, X. S.

2018-02-01

Two symmetric tilt grain boundaries (GBs) (Σ3〈110〉{112} and Σ11〈110〉{332}) in alpha iron were performed to investigate the dynamics of defect-loaded GBs under shear deformation. The results show that the loaded self-interstitial atoms (SIAs) reduce the critical stress of the coupled GB motion in the Σ3 GB, but increase the critical stress in the Σ11 GB. The loaded SIAs in the Σ3 GB easily form 〈111〉 clusters and remain in the bulk when the GB moves away. However, the SIAs move along with the Σ11 GB and combine with the vacancies in the bulk, leading to the defect self-healing. The helium (He) atoms loaded into the GBs significantly affect the coupled GB motion. Once He clusters emit interstitials, the Σ11 GB carries those interstitials away but the Σ3 does not. The loaded He atoms reduce the critical stress of the Σ3 GB, but increase the critical stress of the Σ11 GB.

Primary Ovarian Insufficiency: X chromosome defects and autoimmunity.

Science.gov (United States)

Persani, Luca; Rossetti, Raffaella; Cacciatore, Chiara; Bonomi, Marco

2009-08-01

Premature ovarian failure (POF) is a primary ovarian defect characterized by absent menarche or premature depletion of ovarian follicles before the age of 40 years. However, in several instances the distinction between definitive or intermittent POF may be difficult on clinical bases, therefore the more appropriate term Primary Ovarian Insufficiency (POI) has been recently proposed and will be used in this review. POI is a heterogeneous disorder affecting approximately 1% of women disappearance of menstrual cycles (secondary amenorrhea) associated with a defective folliculogenesis. POI is generally characterized by low levels of gonadal hormones (estrogens and inhibins) and high levels of gonadotropins (LH and FSH) (hypergonadotropic amenorrhea). Heterogeneity of POI is reflected by the variety of possible causes, including autoimmunity, toxics, drugs, as well as genetic defects. Several data indicate that POI has a strong genetic component. In this manuscript we discuss the X chromosome abnormalities that are associated with POI.

Genetic restoration in the eastern collared lizard under prescribed woodland burning.

Science.gov (United States)

Neuwald, Jennifer L; Templeton, Alan R

2013-07-01

Eastern collared lizards of the Ozarks live in glades--open, rocky habitats embedded in a woodland matrix. Past fire suppression had made the woodlands a barrier to dispersal, leading to habitat destruction, fragmentation and local extinction. Reintroduced populations of lizards were subjected to 10 years of habitat fragmentation under continued fire suppression followed by twelve years of landscape restoration with prescribed burns. Prior to prescribed burning, genetic diversity decreased within glades and differentiation increased among glades. With woodland burning, genetic diversity within glades first decreased during an expanding colonization phase, but then increased as a dynamically stable metapopulation was established. Population differentiation among glades also stabilized in the metapopulation under weak isolation-by-distance. This study is one of the first to examine the genetic changes in a species of conservation concern throughout all the stages of decline and recovery and shows the importance of landscape-level restoration for maintaining the genetic integrity of populations. This study also demonstrates how mark-recapture and genetic data together can yield detailed insight into metapopulation dynamics that would be impossible from just one type of data alone. © 2013 John Wiley & Sons Ltd.

Dominance genetic variance for traits under directional selection in Drosophila serrata.

Science.gov (United States)

Sztepanacz, Jacqueline L; Blows, Mark W

2015-05-01

In contrast to our growing understanding of patterns of additive genetic variance in single- and multi-trait combinations, the relative contribution of nonadditive genetic variance, particularly dominance variance, to multivariate phenotypes is largely unknown. While mechanisms for the evolution of dominance genetic variance have been, and to some degree remain, subject to debate, the pervasiveness of dominance is widely recognized and may play a key role in several evolutionary processes. Theoretical and empirical evidence suggests that the contribution of dominance variance to phenotypic variance may increase with the correlation between a trait and fitness; however, direct tests of this hypothesis are few. Using a multigenerational breeding design in an unmanipulated population of Drosophila serrata, we estimated additive and dominance genetic covariance matrices for multivariate wing-shape phenotypes, together with a comprehensive measure of fitness, to determine whether there is an association between directional selection and dominance variance. Fitness, a trait unequivocally under directional selection, had no detectable additive genetic variance, but significant dominance genetic variance contributing 32% of the phenotypic variance. For single and multivariate morphological traits, however, no relationship was observed between trait-fitness correlations and dominance variance. A similar proportion of additive and dominance variance was found to contribute to phenotypic variance for single traits, and double the amount of additive compared to dominance variance was found for the multivariate trait combination under directional selection. These data suggest that for many fitness components a positive association between directional selection and dominance genetic variance may not be expected. Copyright © 2015 by the Genetics Society of America.

Metastable gravity on classical defects

International Nuclear Information System (INIS)

Ringeval, Christophe; Rombouts, Jan-Willem

2005-01-01

We discuss the realization of metastable gravity on classical defects in infinite-volume extra dimensions. In dilatonic Einstein gravity, it is found that the existence of metastable gravity on the defect core requires violation of the dominant energy condition for codimension N c =2 defects. This is illustrated with a detailed analysis of a six-dimensional hyperstring minimally coupled to dilaton gravity. We present the general conditions under which a codimension N c >2 defect admits metastable modes, and find that they differ from lower codimensional models in that, under certain conditions, they do not require violation of energy conditions to support quasilocalized gravity

Integrating genetic and toxicogenomic information for determining underlying susceptibility to developmental disorders.

Science.gov (United States)

Robinson, Joshua F; Port, Jesse A; Yu, Xiaozhong; Faustman, Elaine M

2010-10-01

To understand the complex etiology of developmental disorders, an understanding of both genetic and environmental risk factors is needed. Human and rodent genetic studies have identified a multitude of gene candidates for specific developmental disorders such as neural tube defects (NTDs). With the emergence of toxicogenomic-based assessments, scientists now also have the ability to compare and understand the expression of thousands of genes simultaneously across strain, time, and exposure in developmental models. Using a systems-based approach in which we are able to evaluate information from various parts and levels of the developing organism, we propose a framework for integrating genetic information with toxicogenomic-based studies to better understand gene-environmental interactions critical for developmental disorders. This approach has allowed us to characterize candidate genes in the context of variables critical for determining susceptibility such as strain, time, and exposure. Using a combination of toxicogenomic studies and complementary bioinformatic tools, we characterize NTD candidate genes during normal development by function (gene ontology), linked phenotype (disease outcome), location, and expression (temporally and strain-dependent). In addition, we show how environmental exposures (cadmium, methylmercury) can influence expression of these genes in a strain-dependent manner. Using NTDs as an example of developmental disorder, we show how simple integration of genetic information from previous studies into the standard microarray design can enhance analysis of gene-environment interactions to better define environmental exposure-disease pathways in sensitive and resistant mouse strains. © Wiley-Liss, Inc.

Birth Defects in the Newborn Population: Race and Ethnicity

Directory of Open Access Journals (Sweden)

Alexander C. Egbe

2015-06-01

Conclusion: This is a comprehensive description of racial differences in the risk of birth defects in the United States. Observed racial differences in the risk of birth defects may be related to genetic susceptibilities, to cultural or social differences that could modify exposures, or to the many potential combinations between susceptibilities and exposures.

Using bayesian models to assess the effects of under-reporting of cannabis use on the association with birth defects, national birth defects prevention study, 1997-2005

NARCIS (Netherlands)

Gelder, M.M.H.J. van; Donders, A.R.T.; Devine, O.; Roeleveld, N.; Reefhuis, J.; Prevention, S. National Birth

2014-01-01

BACKGROUND: Studies on associations between periconceptional cannabis exposure and birth defects have mainly relied on self-reported exposure. Therefore, the results may be biased due to under-reporting of the exposure. The aim of this study was to quantify the potential effects of this form of

Genetic Testing: MedlinePlus Health Topic

Science.gov (United States)

... Your Family's Health (National Institutes of Health) - PDF Topic Image MedlinePlus Email Updates Get Genetic Testing updates ... testing and your cancer risk Karyotyping Related Health Topics Birth Defects Genetic Counseling Genetic Disorders Newborn Screening ...

Peeling skin syndrome: genetic defects in late terminal differentiation of the epidermis.

Science.gov (United States)

Bowden, Paul E

2011-03-01

In this issue, Israeli and colleagues confirm that homozygous mutations in corneodesmosin (CDSN) cause type B peeling skin syndrome (PSS), an autosomal recessive skin disorder. The deletion mutation described resulted in a frameshift, producing a downstream premature stop codon and early truncation of the protein. The recently described CDSN nonsense mutation in another PSS family also resulted in protein truncation and nonsense-mediated mRNA decay. Type B generalized PSS can now be clearly distinguished from acral PSS, caused by mutations in transglutaminase 5. This directly affects cornified envelope cross-linking rather than corneodesmosome adherence. These observations provide new insight into the molecular defects underlying two closely related forms of PSS.

Quo Vadis, Medical Genetics?

Science.gov (United States)

Czeizel, Andrew E.

The beginning of human genetics and its medical part: medical genetics was promising in the early decades of this century. Many genetic diseases and defects with Mendelian origin were identified and it helped families with significant genetic burden to limit their child number. Unfortunately this good start was shadowed by two tragic events. On the one hand, in the 1930s and early 1940s the German fascism brought about the dominance of an unscientific eugenics to mask vile political crimes. People with genetic diseases-defects were forced to sterilisation and several of them were killed. On the other hand, in the 1950s lysenkoism inhibitied the evolution of genetics in the Soviet Union and their satelite countries. Lysenko's doctrine declared genetics as a product of imperialism and a guilty science, therefore leading geneticists were ousted form their posts and some of them were executed or put in prison. Past decades genetics has resulted fantastic new results and achieved a leading position within the natural sciences. To my mind, however, the expected wider use of new eugenics indicates a new tragedy and this Cassandra's prediction is the topic of this presentation.

Computer simulation of defect cluster

Energy Technology Data Exchange (ETDEWEB)

Kuramoto, Eiichi [Kyushu Univ., Kasuga, Fukuoka (Japan). Research Inst. for Applied Mechanics

1996-04-01

In order to elucidate individual element process of various defects and defect clusters of used materials under irradiation environments, interatomic potential with reliability was investigated. And for comparison with experimental results, it is often required to adopt the temperature effect and to investigate in details mechanism of one dimensional motion of micro conversion loop and so forth using the molecular dynamic (MD) method. Furthermore, temperature effect is also supposed for stable structure of defects and defect clusters, and many problems relating to alloy element are also remained. And, simulation on photon life at the defects and defect clusters thought to be important under comparison with equipment can also be supposed an improvement of effectiveness due to relation to theses products. In this paper, some topics in such flow was extracted to explain them. In particular, future important problems will be potential preparation of alloy, structure, dynamic behavior and limited temperature of intralattice atomic cluster. (G.K.)

Analysis of displacement damage and defect production under cascade damage conditions

DEFF Research Database (Denmark)

Zinkle, S.J.; Singh, B.N.

1993-01-01

and residual defect production must be treated separately. An evaluation of experimental and computer defect production studies indicates that the overall fraction of defects surviving correlated annihilation in an energetic displacement cascade in copper decreases from about 30% of the Norgett......-Robinson-Torrens (NRT) calculated displacements at 4 K to about 10% of the NRT displacements at 300 K. Due to differences in the thermal stability of vacancy versus interstitial clusters, the fractions of freely migrating defects available for inducing microstructural changes at elevated temperatures may be higher...... for vacancies than for interstitials. The available evidence suggests that the fraction of freely migrating vacancies at temperatures relevant for void swelling in copper is greater than or similar to 5% of the calculated NRT displacements....

Racial/ethnic variations in the prevalence of selected major birth defects, metropolitan Atlanta, 1994-2005.

Science.gov (United States)

Kucik, James E; Alverson, Clinton J; Gilboa, Suzanne M; Correa, Adolfo

2012-01-01

Birth defects are the leading cause of infant mortality and are responsible for substantial child and adult morbidity. Documenting the variation in prevalence of birth defects among racial/ethnic subpopulations is critical for assessing possible variations in diagnosis, case ascertainment, or risk factors among such groups. We used data from the Metropolitan Atlanta Congenital Defects Program, a population-based birth defects registry with active case ascertainment. We estimated the racial/ethnic variation in prevalence of 46 selected major birth defects among live births, stillbirths, and pregnancy terminations at >20 weeks gestation among mothers residing in the five central counties of metropolitan Atlanta between 1994 and 2005, adjusting for infant sex, maternal age, gravidity, and socioeconomic status (SES). We also explored SES as a potential effect measure modifier. Compared with births to non-Hispanic white women, births to non-Hispanic black women had a significantly higher prevalence of five birth defects and a significantly lower prevalence of 10 birth defects, while births to Hispanic women had a significantly higher prevalence of four birth defects and a significantly lower prevalence of six birth defects. The racial/ethnic disparities in the prevalence of some defects varied by SES, but no clear pattern emerged. Racial/ethnic disparities were suggested in 57% of included birth defects. Disparities in the prevalence of birth defects may result from different underlying genetic susceptibilities; exposure to risk factors; or variability in case diagnosis, ascertainment, or reporting among the subpopulations examined. Policies that improve early diagnosis of birth defects could reduce associated morbidity and mortality.

Identification of genetic defects in primary immunodeficiencies by whole exome sequencing

DEFF Research Database (Denmark)

Christiansen, Mette; Jensen, Jens Magnus Bernth; Veirum, Jens Erik

2014-01-01

to hypogammaglobulinaemia, and increased risk of both infections as well as cancer. We employed whole exome sequencing (WES) to identify mutations associated with primary immunodeficiency in severely affected children. We present WES data on 2 patients with severe immunodeficiency. WES was performed using TruSeq exome kit...... and severe infections including sepsis. Second, we identified compound heterozygote stopgain mutations in RAD52 and a heterozygote mutation in LRRC8A in a 7 year-old girl with T-cell deficiency, reduced T-cell mediated B-cell activity, hypogammaglobulinaemia, prolonged splenomegali and benign adenopathy. RAD......52 has not previously been linked to immunodeficiency and we are currently investigating the functional consequences. Knowledge of the mechanisms underlying immunodeficiencies is a prerequisite for understanding disease pathogenesis. WES allows the demonstration of immune defects that may result from...

Defects in medical X-ray equipment

International Nuclear Information System (INIS)

Eder, H.; Wahl, H.; Troeger, W.

1979-01-01

A careful estimate of the effects on the genetically significant radiation load shows that it is in the same order of magnitude as the increase in the skin dose area product. This is to say that of the genetically significant radiation dose of about 500 mJ/kg (50 mrem) per year and person due to medical X-ray diagnostics, about 75 mJ/kg (7.5 mrem) are due to serious defects in X-ray equipment. (orig.) [de

Genetic Syndromes Associated with Congenital Cardiac Defects and Ophthalmologic Changes - Systematization for Diagnosis in the Clinical Practice

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Priscila H. A. Oliveira

Full Text Available Abstract Background: Numerous genetic syndromes associated with heart disease and ocular manifestations have been described. However, a compilation and a summarization of these syndromes for better consultation and comparison have not been performed yet. Objective: The objective of this work is to systematize available evidence in the literature on different syndromes that may cause congenital heart diseases associated with ocular changes, focusing on the types of anatomical and functional changes. Method: A systematic search was performed on Medline electronic databases (PubMed, Embase, Cochrane, Lilacs of articles published until January 2016. Eligibility criteria were case reports or review articles that evaluated the association of ophthalmic and cardiac abnormalities in genetic syndrome patients younger than 18 years. Results: The most frequent genetic syndromes were: Down Syndrome, Velo-cardio-facial / DiGeorge Syndrome, Charge Syndrome and Noonan Syndrome. The most associated cardiac malformations with ocular findings were interatrial communication (77.4%, interventricular communication (51.6%, patent ductus arteriosus (35.4%, pulmonary artery stenosis (25.8% and tetralogy of Fallot (22.5%. Conclusion: Due to their clinical variability, congenital cardiac malformations may progress asymptomatically to heart defects associated with high morbidity and mortality. For this reason, the identification of extra-cardiac characteristics that may somehow contribute to the diagnosis of the disease or reveal its severity is of great relevance.

Genetic Counseling: MedlinePlus Health Topic

Science.gov (United States)

... Craniosynostosis as a clinical and diagnostic problem: molecular pathology and... Article: GENETICS IN ENDOCRINOLOGY: Genetic counseling for congenital ... March of Dimes Birth Defects Foundation Also in Spanish ...

Developmental defects in zebrafish for classification of EGF pathway inhibitors

Energy Technology Data Exchange (ETDEWEB)

Pruvot, Benoist; Curé, Yoann; Djiotsa, Joachim; Voncken, Audrey; Muller, Marc, E-mail: m.muller@ulg.ac.be

2014-01-15

One of the major challenges when testing drug candidates targeted at a specific pathway in whole animals is the discrimination between specific effects and unwanted, off-target effects. Here we used the zebrafish to define several developmental defects caused by impairment of Egf signaling, a major pathway of interest in tumor biology. We inactivated Egf signaling by genetically blocking Egf expression or using specific inhibitors of the Egf receptor function. We show that the combined occurrence of defects in cartilage formation, disturbance of blood flow in the trunk and a decrease of myelin basic protein expression represent good indicators for impairment of Egf signaling. Finally, we present a classification of known tyrosine kinase inhibitors according to their specificity for the Egf pathway. In conclusion, we show that developmental indicators can help to discriminate between specific effects on the target pathway from off-target effects in molecularly targeted drug screening experiments in whole animal systems. - Highlights: • We analyze the functions of Egf signaling on zebrafish development. • Genetic blocking of Egf expression causes cartilage, myelin and circulatory defects. • Chemical inhibition of Egf receptor function causes similar defects. • Developmental defects can reveal the specificity of Egf pathway inhibitors.

Developmental defects in zebrafish for classification of EGF pathway inhibitors

International Nuclear Information System (INIS)

Pruvot, Benoist; Curé, Yoann; Djiotsa, Joachim; Voncken, Audrey; Muller, Marc

2014-01-01

One of the major challenges when testing drug candidates targeted at a specific pathway in whole animals is the discrimination between specific effects and unwanted, off-target effects. Here we used the zebrafish to define several developmental defects caused by impairment of Egf signaling, a major pathway of interest in tumor biology. We inactivated Egf signaling by genetically blocking Egf expression or using specific inhibitors of the Egf receptor function. We show that the combined occurrence of defects in cartilage formation, disturbance of blood flow in the trunk and a decrease of myelin basic protein expression represent good indicators for impairment of Egf signaling. Finally, we present a classification of known tyrosine kinase inhibitors according to their specificity for the Egf pathway. In conclusion, we show that developmental indicators can help to discriminate between specific effects on the target pathway from off-target effects in molecularly targeted drug screening experiments in whole animal systems. - Highlights: • We analyze the functions of Egf signaling on zebrafish development. • Genetic blocking of Egf expression causes cartilage, myelin and circulatory defects. • Chemical inhibition of Egf receptor function causes similar defects. • Developmental defects can reveal the specificity of Egf pathway inhibitors

Aggregation of Frenkel defects under irradiation: a mesoscopic approach

International Nuclear Information System (INIS)

Soppe, W.; Kotomin, E.

1993-08-01

The radiation-induced aggregation of Frenkel defects in solids is studied in terms of a mesoscopic approach. The asymmetry in elastic interactions between mobile interstitials (I-I) and between interstitials and vacancies (I-V) plays a decisive role in the aggregation of similar defects. The conditions for defect aggregation are studied in detail for NaCl crystals. The critical dose rate for aggregation has been calculated as a function of the temperature as well as the aggregation rate as a function of temperature and dose rate. Furthermore, the role of deep traps (like impurities and di-vacancies), reducing the mobility of interstitials, and the role of dislocations serving as sinks for interstitials, are studied. The aggregation appears to reach a maximum at a distinct temperature which is in agreement both with experiment and the Jain-Lidiard theory. The model also predicts a shift of this maximum towards lower temperatures if the dose rate is decreased. The consequences of the model for the disposal of nuclear waste in rock salt formations, are briefly discussed. (orig.)

Defective Glycinergic Synaptic Transmission in Zebrafish Motility Mutants

OpenAIRE

Hirata, Hiromi; Carta, Eloisa; Yamanaka, Iori; Harvey, Robert J.; Kuwada, John Y.

2010-01-01

Glycine is a major inhibitory neurotransmitter in the spinal cord and brainstem. Recently, in vivo analysis of glycinergic synaptic transmission has been pursued in zebrafish using molecular genetics. An ENU mutagenesis screen identified two behavioral mutants that are defective in glycinergic synaptic transmission. Zebrafish bandoneon (beo) mutants have a defect in glrbb, one of the duplicated glycine receptor (GlyR) β subunit genes. These mutants exhibit a loss of glycinergic synaptic ...

Genetic polymorphisms of the TYMS gene are not associated with congenital cardiac septal defects in a Han Chinese population.

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Jian-Yuan Zhao

Full Text Available BACKGROUND: Clinical research indicates that periconceptional administration of folic acid can reduce the occurrence of congenital cardiac septal defects (CCSDs. The vital roles of folate exhibits in three ways: the unique methyl donor for DNA expression regulation, the de novo biosynthesis of purine and pyrimidine for DNA construction, and the serum homocysteine removal. Thymidylate synthase (TYMS is the solo catalysis enzyme for the de novo synthesis of dTMP, which is the essential precursor of DNA biosynthesis and repair process. To examine the role of TYMS in Congenital Cardiac Septal Defects (CCSDs risk, we investigated whether genetic polymorphisms in the TYMS gene associated with the CCSDs in a Han Chinese population. METHOD: Polymorphisms in the noncoding region of TYMS were identified via direct sequencing in 32 unrelated individuals composed of half CCSDs and half control subjects. Nine SNPs and two insertion/deletion polymorphisms were genotyped from two independent case-control studies involving a total of 529 CCSDs patients and 876 healthy control participants. The associations were examined by both single polymorphism and haplotype tests using logistic regression. RESULT: We found that TYMS polymorphisms were not related to the altered CCSDs risk, and even to the changed risk of VSDs subgroup, when tested in both studied groups separately or in combination. In the haplotype analysis, there were no haplotypes significantly associated with risks for CCSDs either. CONCLUSION: Our results show no association between common genetic polymorphisms of the regulatory region of the TYMS gene and CCSDs in the Han Chinese population.

Why increased nuchal translucency is associated with congenital heart disease: a systematic review on genetic mechanisms

NARCIS (Netherlands)

Burger, N.B.; Bekker, M.N.; Groot, C.J. de; Christoffels, V.M.; Haak, M.C.

2015-01-01

This overview provides insight into the underlying genetic mechanism of the high incidence of cardiac defects in fetuses with increased nuchal translucency (NT). Nuchal edema, the morphological equivalent of increased NT, is likely to result from abnormal lymphatic development and is strongly

Genetic data and the listing of species under the U.S. Endangered Species Act.

Science.gov (United States)

Fallon, Sylvia M

2007-10-01

Genetic information is becoming an influential factor in determining whether species, subspecies, and distinct population segments qualify for protection under the U.S. Endangered Species Act. Nevertheless, there are currently no standards or guidelines that define how genetic information should be used by the federal agencies that administer the act. I examined listing decisions made over a 10-year period (February 1996-February 2006) that relied on genetic information. There was wide variation in the genetic data used to inform listing decisions in terms of which genomes (mitochondrial vs. nuclear) were sampled and the number of markers (or genetic techniques) and loci evaluated. In general, whether the federal agencies identified genetic distinctions between putative taxonomic units or populations depended on the type and amount of genetic data. Studies that relied on multiple genetic markers were more likely to detect distinctions, and those organisms were more likely to receive protection than studies that relied on a single genetic marker. Although the results may, in part, reflect the corresponding availability of genetic techniques over the given time frame, the variable use of genetic information for listing decisions has the potential to misguide conservation actions. Future management policy would benefit from guidelines for the critical evaluation of genetic information to list or delist organisms under the Endangered Species Act.

Multiobjective genetic algorithm approaches to project scheduling under risk

OpenAIRE

Kılıç, Murat; Kilic, Murat

2003-01-01

In this thesis, project scheduling under risk is chosen as the topic of research. Project scheduling under risk is defined as a biobjective decision problem and is formulated as a 0-1 integer mathematical programming model. In this biobjective formulation, one of the objectives is taken as the expected makespan minimization and the other is taken as the expected cost minimization. As the solution approach to this biobjective formulation genetic algorithm (GA) is chosen. After carefully invest...

Genetic causes of congenital brain malformations in epilepsy patients

DEFF Research Database (Denmark)

Møller, Rikke Steensbjerre

2008-01-01

The search for genetic causes of congenital brain malformations, severe epilepsy and mental retardation plays an important role in neuropediatrics and neurology. Disclosure of the aetiology of the intellectual disabilities, seizures and the underlying brain malformation may be of psychological va...... genes for developmental brain defects. The overall aim of the present study has been to identify new candidate genes or predisposing factors involved in congenital brain malformations in epilepsy patients.......The search for genetic causes of congenital brain malformations, severe epilepsy and mental retardation plays an important role in neuropediatrics and neurology. Disclosure of the aetiology of the intellectual disabilities, seizures and the underlying brain malformation may be of psychological...... value for the family, and it is essential for proper genetic counselling. The human brain is one of the most complex structures known, and probably many of the 25.000- 30.000 genes that comprise the human genome are involved in its development, which means that thousands of genes could be candidate...

Common genetic architecture underlying young children's food fussiness and liking for vegetables and fruit.

Science.gov (United States)

Fildes, Alison; van Jaarsveld, Cornelia H M; Cooke, Lucy; Wardle, Jane; Llewellyn, Clare H

2016-04-01

Food fussiness (FF) is common in early childhood and is often associated with the rejection of nutrient-dense foods such as vegetables and fruit. FF and liking for vegetables and fruit are likely all heritable phenotypes; the genetic influence underlying FF may explain the observed genetic influence on liking for vegetables and fruit. Twin analyses make it possible to get a broad-based estimate of the extent of the shared genetic influence that underlies these traits. We quantified the extent of the shared genetic influence that underlies FF and liking for vegetables and fruit in early childhood with the use of a twin design. Data were from the Gemini cohort, which is a population-based sample of twins born in England and Wales in 2007. Parents of 3-y-old twins (n= 1330 pairs) completed questionnaire measures of their children's food preferences (liking for vegetables and fruit) and the FF scale from the Children's Eating Behavior Questionnaire. Multivariate quantitative genetic modeling was used to estimate common genetic influences that underlie FF and liking for vegetables and fruit. Genetic correlations were significant and moderate to large in size between FF and liking for both vegetables (-0.65) and fruit (-0.43), which indicated that a substantial proportion of the genes that influence FF also influence liking. Common genes that underlie FF and liking for vegetables and fruit largely explained the observed phenotypic correlations between them (68-70%). FF and liking for fruit and vegetables in young children share a large proportion of common genetic factors. The genetic influence on FF may determine why fussy children typically reject fruit and vegetables.

Sirenomelia: A Multi-systemic Polytopic Field Defect with Ongoing Controversies.

Science.gov (United States)

Boer, Lucas L; Morava, Eva; Klein, Willemijn M; Schepens-Franke, Annelieke N; Oostra, Roelof Jan

2017-06-01

The most impressive phenotypic appearance of sirenomelia is the presence of a 180°-rotated, axially positioned, single lower limb. Associated gastrointestinal and genitourinary anomalies are almost always present. This rare anomaly is still the subject of ongoing controversies concerning its nosology, pathogenesis, and possible genetic etiology. Sirenomelia can be part of a syndromic continuum, overlapping with other complex conditions including caudal dysgenesis and VATER/VACTERL/VACTERL-H associations, which could all be part of a heterogeneous spectrum, and originate from an early defect in blastogenesis. It is imaginable that different "primary field defects," whether or not genetically based, induce a spectrum of caudal malformations. In the current study, we review the contemporary hypotheses and conceptual approaches regarding the etiology and pathogenesis of sirenomelia, especially in the context of concomitant conditions. To expand on the latter, we included the external and internal dysmorphology of one third trimester sirenomelic fetus from our anatomical museum collection, in which multiple concomitant but discordant anomalies were observed compared with classic sirenomelia, and was diagnosed as VACTERL-H association with sirenomelia. Birth Defects Research 109:791-804, 2017. © 2017 The Authors. Birth Defects Research Published by Wiley Periodicals, Inc. © 2017 The Authors. Birth Defects Research Published by Wiley Periodicals, Inc.

Genetic determinants of facial clefting

DEFF Research Database (Denmark)

Jugessur, Astanand; Shi, Min; Gjessing, Håkon Kristian

2009-01-01

BACKGROUND: Facial clefts are common birth defects with a strong genetic component. To identify fetal genetic risk factors for clefting, 1536 SNPs in 357 candidate genes were genotyped in two population-based samples from Scandinavia (Norway: 562 case-parent and 592 control-parent triads; Denmark...

Magnetoencephalography signals are influenced by skull defects.

Science.gov (United States)

Lau, S; Flemming, L; Haueisen, J

2014-08-01

Magnetoencephalography (MEG) signals had previously been hypothesized to have negligible sensitivity to skull defects. The objective is to experimentally investigate the influence of conducting skull defects on MEG and EEG signals. A miniaturized electric dipole was implanted in vivo into rabbit brains. Simultaneous recording using 64-channel EEG and 16-channel MEG was conducted, first above the intact skull and then above a skull defect. Skull defects were filled with agar gels, which had been formulated to have tissue-like homogeneous conductivities. The dipole was moved beneath the skull defects, and measurements were taken at regularly spaced points. The EEG signal amplitude increased 2-10 times, whereas the MEG signal amplitude reduced by as much as 20%. The EEG signal amplitude deviated more when the source was under the edge of the defect, whereas the MEG signal amplitude deviated more when the source was central under the defect. The change in MEG field-map topography (relative difference measure, RDM(∗)=0.15) was geometrically related to the skull defect edge. MEG and EEG signals can be substantially affected by skull defects. MEG source modeling requires realistic volume conductor head models that incorporate skull defects. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Identification of Genetic Defects Underlying FXII Deficiency in Four Unrelated Chinese Patients.

Science.gov (United States)

Yang, Lihong; Wang, Yingyu; Zhou, Jianpin; Cheng, Xiaoli; Hao, Xiuping; Xie, Haixiao; Jin, Yanhui; Wang, Mingshan

2016-01-01

Congenital factor XII (FXII) dexFB01;ciency is a rare autosomal recessive disorder, characterized by a great variability in its clinical manifestations. In this study, we screened for mutations in the F12 gene of 4 unrelated patients with FXII coagulant activity Gly542 Ser), 1 insertion (7142insertC) and 2 deletions (5741-5742 delCA and 6753-6755delACA), were identixFB01;ed on the F12 gene. Three of them (Gly341Arg, 5741-5742delCA and 6753-6755delACA) are reported here for the first time. Computer-based algorithms predicted these missense mutations to be deleterious. This study has increased our knowledge of the mutational spectrum underlying FXII deficiency. © 2016 S. Karger AG, Basel.

Drought genetics have varying influence on corn water stress under differing water availability

Science.gov (United States)

Irrigated corn (Zea mays L.) in the Great Plains will be increasingly grown under limited irrigation management and greater water stress. Hybrids with drought genetics may decrease the impacts of water stress on yield. The objective of this experiment was to evaluate the effect of drought genetics o...

Electrical fingerprint of pipeline defects

International Nuclear Information System (INIS)

Mica, Isabella; Polignano, Maria Luisa; Marco, Cinzia De

2004-01-01

Pipeline defects are dislocations that connect the source region of the transistor with the drain region. They were widely reported to occur in CMOS, BiCMOS devices and recently in SOI technologies. They can reduce device yield either by affecting the devices functionality or by increasing the current consumption under stand-by conditions. In this work the electrical fingerprint of these dislocations is studied, its purpose is to enable us to identify these defects as the ones responsible for device failure. It is shown that the pipeline defects are responsible for a leakage current from source to drain in the transistors. This leakage has a resistive characteristic and it is lightly modulated by the body bias. It is not sensitive to temperature; vice versa the off-current of a good transistor exhibits the well-known exponential dependence on 1/T. The emission spectrum of these defects was studied and compared with the spectrum of a good transistor. The paper aims to show that the spectrum of a defective transistor is quite peculiar; it shows well defined peaks, whereas the spectrum of a good transistor under saturation conditions is characterized by a broad spectral light emission distribution. Finally the deep-level transient spectroscopy (DLTS) is tried on defective diodes

Genetics of SCID

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Cossu Fausto

2010-11-01

Full Text Available Abstract Human SCID (Severe Combined Immunodeficiency is a prenatal disorder of T lymphocyte development, that depends on the expression of numerous genes. The knowledge of the genetic basis of SCID is essential for diagnosis (e.g., clinical phenotype, lymphocyte profile and treatment (e.g., use and type of pre-hematopoietic stem cell transplant conditioning. Over the last years novel genetic defects causing SCID have been discovered, and the molecular and immunological mechanisms of SCID have been better characterized. Distinct forms of SCID show both common and peculiar (e.g., absence or presence of nonimmunological features aspects, and they are currently classified into six groups according to prevalent pathophysiological mechanisms: impaired cytokine-mediated signaling; pre-T cell receptor defects; increased lymphocyte apoptosis; defects in thymus embryogenesis; impaired calcium flux; other mechanisms. This review is the updated, extended and largely modified translation of the article "Cossu F: Le basi genetiche delle SCID", originally published in Italian language in the journal "Prospettive in Pediatria" 2009, 156:228-238.

Daf-2, Daf-16 and Daf-23: Genetically Interacting Genes Controlling Dauer Formation in Caenorhabditis Elegans

OpenAIRE

Gottlieb, S.; Ruvkun, G.

1994-01-01

Under conditions of high population density and low food, Caenorhabditis elegans forms an alternative third larval stage, called the dauer stage, which is resistant to desiccation and harsh environments. Genetic analysis of some dauer constitutive (Daf-c) and dauer defective (Daf-d) mutants has revealed a complex pathway that is likely to function in particular neurons and/or responding tissues. Here we analyze the genetic interactions between three genes which comprise a branch of the dauer ...

Study of supersaturation of defects under neutron irradiation by Zener relaxation

International Nuclear Information System (INIS)

Gonzalez, Hector C.; Justus, Francisco J.W.

2004-01-01

Vacancy supersaturation in dynamic equilibrium under fast neutron irradiation could be determined by anelastic relaxation. This phenomenon is particularly noticeable in some substitutional binary alloys. Relaxation is due to the reordering of atoms pairs under a stress, being a local reordering at the atomic scale. Relaxation time (τ) is inversely proportional to the vacancy concentration (Cv) and decreases under irradiation because a dynamical equilibrium of vacancy concentration, higher than thermodynamic equilibrium, is established. Theoretical models allow estimating the magnitude of that supersaturation. Determinations of τ at different temperatures, with and without fast neutron irradiations, were made with an 'in situ' device placed in the high temperature loop in the RA1 CAC-CNEA reactor. An alloy Au-30% Ni was used, since it presents an appreciable Zener effect. The measurements were performed in a spring-shaped specimen in order to minimize temperature and flux gradients. An Arrhenius plot of τ was obtained, and it was observed that for temperatures lower than 220 C degrees a vacancy supersaturation exists. The lowest temperature of our experiments was 190 C degrees. A value of τ at this temperature was three times lower under irradiations. A plot of τ vs. fast neutron fluence (φ f t) at the irradiation temperature T= 203 C degrees was obtained. An increase of τ was observed. After an annealing at T = 280 C degrees, the value of τ recovers the value corresponding to the unirradiated case. This fact suggests that the loops produced by irradiation act as defect sinks. (author) [es

The failure of brittle materials under overall compression: Effects of loading rate and defect distribution

Science.gov (United States)

Paliwal, Bhasker

brittle materials. The model incorporates pre-existing defect distributions and a crack growth law. The damage is defined as a scalar parameter which is a function of the micro-crack density, the evolution of which is a function of the existing defect distribution and the crack growth dynamics. A specific case of a uniaxial compressive loading under constant strain-rate has been studied to predict the effects of the strain-rate, defect distribution and the crack growth dynamics on the constitutive response and failure behavior of brittle materials. Finally, the effects of crack growth dynamics on the strain-rate sensitivity of brittle materials are studied with the help of the micro-mechanical damage model. The results are compared with the experimentally observed damage evolution and the rate-sensitive behavior of the compressive strength of several engineering ceramics. The dynamic failure of armor-grade hot-pressed boron carbide (B 4C) under loading rates of ˜ 5X10-6 to 200 MPa/mus is also discussed.

Defect production in silica glasses under gamma-irradiation at the quenched nuclear reactor

International Nuclear Information System (INIS)

Mussaeva, M.A.; Kalanov, M.U.; Ibragimova, E.M.; Sandalov, V.N.; Muminov, M.L.

2004-01-01

Full text: Radiation defect production in oxides is highly interesting for atom and solar energy, and also for burying nuclear waste. Combine effect of neutron and gamma-radiation on materials was studied extensively and only neutrons are believed to displace atoms, although 60 Co-gamma quanta were proved to displace light anions (O, F) by inelastic mechanism. On the example of polished plates of pure fused quartz and barium-silica glasses containing nano-crystalline inclusions, and also nano-porous glass, the effect of gamma-radiation of the quenched reactor was studied in the energy range of 0.2-7 MeV. The time period was selected when practically constant current ∼10-20 nA is maintained in the ionizing chamber, corresponding to the average gamma-flux of 15-30 Gy/s. Optical absorption and photoluminescence spectra and also structure of the grasses were studied. It turned out, that the charged oxygen vacancies accumulation rate is higher in Barium glass than in the pure one, because for SiO 2 with small Z the photoelectric effect is weak, while the Compton scattering and photonuclear reactions prevail, and for Barium - just the opposite. The radiation-induced growth of the crystalline precipitates was noticed in the both glasses, which before had been attributed to the elastic atom displacements by fast neutrons. The density of Ba-glass increases with irradiation. The efficiency of defect production by the gamma-component even of the quenched reactor turned out much higher than that under irradiation with 60 Co gamma-source of ∼1.25 MeV to the equivalent dose at the current dose rate of ∼ 7 Gy/s (and before at 45 Gy/s). A 100-times increase of the surface proton conductivity was discovered in the porous glasses under gamma-irradiation due to water vapor radiolysis on the pore surface. The irradiated porous glass is recommended as an active electrode in the hydrogen fuel element. The work was done under the grant F2.1.2 from Center of Science and Technology

Integrated Supply Chain Cooperative Inventory Model with Payment Period Being Dependent on Purchasing Price under Defective Rate Condition

Directory of Open Access Journals (Sweden)

Ming-Feng Yang

2015-01-01

Full Text Available In most commercial transactions, the buyer and vendor may usually agree to postpone payment deadline. During such delayed period, the buyer is entitled to keep the products without having to pay the sale price. However, the vendor usually hopes to receive full payment as soon as possible, especially when the transaction involves valuable items; yet, the buyer would offer a higher purchasing price in exchange of a longer postponement. Therefore, we assumed such permissible delayed period is dependent on the purchasing price. As for the manufacturing side, defective products are inevitable from time to time, and not all of those defective products can be repaired. Hence, we would like to add defective production and repair rate to our proposed model and discuss how these factors may affect profits. In addition, holding cost, ordering cost, and transportation cost will also be considered as we develop the integrated inventory model with price-dependent payment period under the possible condition of defective products. We would like to find the maximum of the joint expected total profit for our model and come up with a suitable inventory policy accordingly. In the end, we have also provided a numerical example to clearly illustrate possible solutions.

Cloud Computing Task Scheduling Based on Cultural Genetic Algorithm

Directory of Open Access Journals (Sweden)

Li Jian-Wen

2016-01-01

Full Text Available The task scheduling strategy based on cultural genetic algorithm(CGA is proposed in order to improve the efficiency of task scheduling in the cloud computing platform, which targets at minimizing the total time and cost of task scheduling. The improved genetic algorithm is used to construct the main population space and knowledge space under cultural framework which get independent parallel evolution, forming a mechanism of mutual promotion to dispatch the cloud task. Simultaneously, in order to prevent the defects of the genetic algorithm which is easy to fall into local optimum, the non-uniform mutation operator is introduced to improve the search performance of the algorithm. The experimental results show that CGA reduces the total time and lowers the cost of the scheduling, which is an effective algorithm for the cloud task scheduling.

The Genetics Underlying Vernalization in Timothy (Phleum pratense L.)

DEFF Research Database (Denmark)

Fiil, Alice

Vernalization is the process where the transition from the vegetative to the reproductive state is promoted by a prolonged period of cold. Timothy (Phleum pratense L.) is an important forage grass in the Nordic countries. Unlike many other temperate grasses, a vernalization requirement has not been...... reported in this species. The objectives of this Ph.D. study were to obtain a better understanding of vernalization in timothy and knowledge about the genetics underlying the vernalization response. The vernalization response was analyzed in 38 genotypes of diverse geographic origin. Vernalization...... that significant genetic variation for the vernalization response is present within timothy and suggest that differential regulation of VRN1 transcription discriminates genotypes with contrasting vernalization responses. In addition, the nucleotide diversity and linkage disequilibrium were analyzed in nine genes...

simEye: computer-based simulation of visual perception under various eye defects using Zernike polynomials

OpenAIRE

Fink, Wolfgang; Micol, Daniel

2006-01-01

We describe a computer eye model that allows for aspheric surfaces and a three-dimensional computer-based ray-tracing technique to simulate optical properties of the human eye and visual perception under various eye defects. Eye surfaces, such as the cornea, eye lens, and retina, are modeled or approximated by a set of Zernike polynomials that are fitted to input data for the respective surfaces. A ray-tracing procedure propagates light rays using Snell’s law of refraction from an input objec...

Defects at oxide surfaces

CERN Document Server

Thornton, Geoff

2015-01-01

This book presents the basics and characterization of defects at oxide surfaces. It provides a state-of-the-art review of the field, containing information to the various types of surface defects, describes analytical methods to study defects, their chemical activity and the catalytic reactivity of oxides. Numerical simulations of defective structures complete the picture developed. Defects on planar surfaces form the focus of much of the book, although the investigation of powder samples also form an important part. The experimental study of planar surfaces opens the possibility of applying the large armoury of techniques that have been developed over the last half-century to study surfaces in ultra-high vacuum. This enables the acquisition of atomic level data under well-controlled conditions, providing a stringent test of theoretical methods. The latter can then be more reliably applied to systems such as nanoparticles for which accurate methods of characterization of structure and electronic properties ha...

Visualizing Angiogenesis by Multiphoton Microscopy In Vivo in Genetically Modified 3D-PLGA/nHAp Scaffold for Calvarial Critical Bone Defect Repair.

Science.gov (United States)

Li, Jian; Jahr, Holger; Zheng, Wei; Ren, Pei-Gen

2017-09-07

The reconstruction of critically sized bone defects remains a serious clinical problem because of poor angiogenesis within tissue-engineered scaffolds during repair, which gives rise to a lack of sufficient blood supply and causes necrosis of the new tissues. Rapid vascularization is a vital prerequisite for new tissue survival and integration with existing host tissue. The de novo generation of vasculature in scaffolds is one of the most important steps in making bone regeneration more efficient, allowing repairing tissue to grow into a scaffold. To tackle this problem, the genetic modification of a biomaterial scaffold is used to accelerate angiogenesis and osteogenesis. However, visualizing and tracking in vivo blood vessel formation in real-time and in three-dimensional (3D) scaffolds or new bone tissue is still an obstacle for bone tissue engineering. Multiphoton microscopy (MPM) is a novel bio-imaging modality that can acquire volumetric data from biological structures in a high-resolution and minimally-invasive manner. The objective of this study was to visualize angiogenesis with multiphoton microscopy in vivo in a genetically modified 3D-PLGA/nHAp scaffold for calvarial critical bone defect repair. PLGA/nHAp scaffolds were functionalized for the sustained delivery of a growth factor pdgf-b gene carrying lentiviral vectors (LV-pdgfb) in order to facilitate angiogenesis and to enhance bone regeneration. In a scaffold-implanted calvarial critical bone defect mouse model, the blood vessel areas (BVAs) in PHp scaffolds were significantly higher than in PH scaffolds. Additionally, the expression of pdgf-b and angiogenesis-related genes, vWF and VEGFR2, increased correspondingly. MicroCT analysis indicated that the new bone formation in the PHp group dramatically improved compared to the other groups. To our knowledge, this is the first time multiphoton microscopy was used in bone tissue-engineering to investigate angiogenesis in a 3D bio-degradable scaffold in

Phenomenological model of photoluminescence degradation and photoinduced defect formation in silicon nanocrystal ensembles under singlet oxygen generation

Energy Technology Data Exchange (ETDEWEB)

Gongalsky, Maxim B., E-mail: mgongalsky@gmail.com; Timoshenko, Victor Yu. [Faculty of Physics, Moscow State M.V. Lomonosov University, 119991 Moscow (Russian Federation)

2014-12-28

We propose a phenomenological model to explain photoluminescence degradation of silicon nanocrystals under singlet oxygen generation in gaseous and liquid systems. The model considers coupled rate equations, which take into account the exciton radiative recombination in silicon nanocrystals, photosensitization of singlet oxygen generation, defect formation on the surface of silicon nanocrystals as well as quenching processes for both excitons and singlet oxygen molecules. The model describes well the experimentally observed power law dependences of the photoluminescence intensity, singlet oxygen concentration, and lifetime versus photoexcitation time. The defect concentration in silicon nanocrystals increases by power law with a fractional exponent, which depends on the singlet oxygen concentration and ambient conditions. The obtained results are discussed in a view of optimization of the photosensitized singlet oxygen generation for biomedical applications.

Semiconductors Under Ion Radiation: Ultrafast Electron-Ion Dynamics in Perfect Crystals and the Effect of Defects

Science.gov (United States)

Lee, Cheng-Wei; Schleife, André

Stability and safety issues have been challenging difficulties for materials and devices under radiation such as solar panels in outer space. On the other hand, radiation can be utilized to modify materials and increase their performance via focused-ion beam patterning at nano-scale. In order to grasp the underlying processes, further understanding of the radiation-material and radiation-defect interactions is required and inevitably involves the electron-ion dynamics that was traditionally hard to capture. By applying Ehrenfest dynamics based on time-dependent density functional theory, we have been able to perform real-time simulation of electron-ion dynamics in MgO and InP/GaP. By simulating a high-energy proton penetrating the material, the energy gain of electronic system can be interpreted as electronic stopping power and the result is compared to existing data. We also study electronic stopping in the vicinity of defects: for both oxygen vacancy in MgO and interface of InP/GaP superlattice, electronic stopping shows strong dependence on the velocity of the proton. To study the energy transfer from electronic system to lattice, simulations of about 100 femto-seconds are performed and we analyze the difference between Ehrenfest and Born-Oppenheimer molecular dynamics.

The Use of Patient-Specific Induced Pluripotent Stem Cells (iPSCs to Identify Osteoclast Defects in Rare Genetic Bone Disorders

Directory of Open Access Journals (Sweden)

I-Ping Chen

2014-12-01

Full Text Available More than 500 rare genetic bone disorders have been described, but for many of them only limited treatment options are available. Challenges for studying these bone diseases come from a lack of suitable animal models and unavailability of skeletal tissues for studies. Effectors for skeletal abnormalities of bone disorders may be abnormal bone formation directed by osteoblasts or anomalous bone resorption by osteoclasts, or both. Patient-specific induced pluripotent stem cells (iPSCs can be generated from somatic cells of various tissue sources and in theory can be differentiated into any desired cell type. However, successful differentiation of hiPSCs into functional bone cells is still a challenge. Our group focuses on the use of human iPSCs (hiPSCs to identify osteoclast defects in craniometaphyseal dysplasia. In this review, we describe the impact of stem cell technology on research for better treatment of such disorders, the generation of hiPSCs from patients with rare genetic bone disorders and current protocols for differentiating hiPSCs into osteoclasts.

Defect-engineered GaN:Mg nanowire arrays for overall water splitting under violet light

International Nuclear Information System (INIS)

Kibria, M. G.; Chowdhury, F. A.; Zhao, S.; Mi, Z.; Trudeau, M. L.; Guo, H.

2015-01-01

We report that by engineering the intra-gap defect related energy states in GaN nanowire arrays using Mg dopants, efficient and stable overall neutral water splitting can be achieved under violet light. Overall neutral water splitting on Rh/Cr 2 O 3 co-catalyst decorated Mg doped GaN nanowires is demonstrated with intra-gap excitation up to 450 nm. Through optimized Mg doping, the absorbed photon conversion efficiency of GaN nanowires reaches ∼43% at 375–450 nm, providing a viable approach to extend the solar absorption of oxide and non-oxide photocatalysts

An optimization method for defects reduction in fiber laser keyhole welding

Science.gov (United States)

Ai, Yuewei; Jiang, Ping; Shao, Xinyu; Wang, Chunming; Li, Peigen; Mi, Gaoyang; Liu, Yang; Liu, Wei

2016-01-01

Laser welding has been widely used in automotive, power, chemical, nuclear and aerospace industries. The quality of welded joints is closely related to the existing defects which are primarily determined by the welding process parameters. This paper proposes a defects optimization method that takes the formation mechanism of welding defects and weld geometric features into consideration. The analysis of welding defects formation mechanism aims to investigate the relationship between welding defects and process parameters, and weld features are considered to identify the optimal process parameters for the desired welded joints with minimum defects. The improved back-propagation neural network possessing good modeling for nonlinear problems is adopted to establish the mathematical model and the obtained model is solved by genetic algorithm. The proposed method is validated by macroweld profile, microstructure and microhardness in the confirmation tests. The results show that the proposed method is effective at reducing welding defects and obtaining high-quality joints for fiber laser keyhole welding in practical production.

Genetics Home Reference: DNMT3A overgrowth syndrome

Science.gov (United States)

... symptoms, including a rounded upper back that also curves to the side ( kyphoscoliosis ), heart defects, flat feet ( ... Information What information about a genetic condition can statistics provide? Why are some genetic conditions more common ...

Defects and Disorder in the Drosophila Eye

Science.gov (United States)

Kim, Sangwoo; Carthew, Richard; Hilgenfeldt, Sascha

Cell division and differentiation tightly control the regular pattern in the normal eye of the Drosophila fruit fly while certain genetic mutations introduce disorder in the form of topological defects. Analyzing data from pupal retinas, we develop a model based on Voronoi construction that explains the defect statistics as a consequence of area variation of individual facets (ommatidia). The analysis reveals a previously unknown systematic long-range area variation that spans the entire eye, with distinct effects on topological disorder compared to local fluctuations. The internal structure of the ommatidia and the stiffness of their interior cells also plays a crucial role in the defect generation. Accurate predictions of the correlation between the area variation and the defect density in both normal and mutant animals are obtained without free parameters. This approach can potentially be applied to cellular systems in many other contexts to identify size-topology correlations near the onset of symmetry breaking. This work has been supported by the NIH (GM098077) and the NSF (Grant No. 1504301).

Natural defects and defects created by ionic implantation in zinc tellurium

International Nuclear Information System (INIS)

Roche, J.P.; Dupuy, M.; Pfister, J.C.

1977-01-01

Various defects have been studied in ZnTe crystals by transmission electron microscope and by scanning electron microscope in cathodo-luminescence mode: grain boundaries, sub-grain boundaries, twins. Ionic implants of boron (100 keV - 2x10 14 and 10 15 ions cm -2 ) were made on these crystals followed by isochrone annealing (30 minutes) of zinc under partial pressure at 550, 650 and 750 0 C. The nature of the defects was determined by transmission electron microscope: these are interstitial loops (b=1/3 ) the size of which varies between 20 A (non-annealed sample) and 180A (annealed at 750 0 C). The transmission electron microscope was also used to make concentration profiles of defects depending on depth. It is found that for the same implant (2x10 14 ions.cm -2 ), the defect peak moves towards the exterior of the crystal as the annealing temperature rises (400 - 1000 and 7000 A for the three annealings). These results are explained from a model which allows for the coalescence of defects and considers the surface of the sample as being the principal source of vacancies. During the annealings, the migration of vacancies brings about the gradual annihilation of the implant defects. The adjustment of certain calculation parameters on the computer result in giving 2 eV as energy value for the formation of vacancies [fr

Genetic studies on leaf rolling and some root traits under drought ...

African Journals Online (AJOL)

Crossing was made between three resistant and two susceptible parents to determine the genetic characteristics under drought conditions during 2002 and 2003 rice growing seasons. The resistant varieties were IET 1444, Moroberekan and Gaori, while the susceptible varieties were Sakha 101 and Sakha 102.

Evaluation of common genetic variants in 82 candidate genes as risk factors for neural tube defects

LENUS (Irish Health Repository)

Pangilinan, Faith

2012-08-02

AbstractBackgroundNeural tube defects (NTDs) are common birth defects (~1 in 1000 pregnancies in the US and Europe) that have complex origins, including environmental and genetic factors. A low level of maternal folate is one well-established risk factor, with maternal periconceptional folic acid supplementation reducing the occurrence of NTD pregnancies by 50-70%. Gene variants in the folate metabolic pathway (e.g., MTHFR rs1801133 (677 C > T) and MTHFD1 rs2236225 (R653Q)) have been found to increase NTD risk. We hypothesized that variants in additional folate\\/B12 pathway genes contribute to NTD risk.MethodsA tagSNP approach was used to screen common variation in 82 candidate genes selected from the folate\\/B12 pathway and NTD mouse models. We initially genotyped polymorphisms in 320 Irish triads (NTD cases and their parents), including 301 cases and 341 Irish controls to perform case–control and family based association tests. Significantly associated polymorphisms were genotyped in a secondary set of 250 families that included 229 cases and 658 controls. The combined results for 1441 SNPs were used in a joint analysis to test for case and maternal effects.ResultsNearly 70 SNPs in 30 genes were found to be associated with NTDs at the p < 0.01 level. The ten strongest association signals (p-value range: 0.0003–0.0023) were found in nine genes (MFTC, CDKN2A, ADA, PEMT, CUBN, GART, DNMT3A, MTHFD1 and T (Brachyury)) and included the known NTD risk factor MTHFD1 R653Q (rs2236225). The single strongest signal was observed in a new candidate, MFTC rs17803441 (OR = 1.61 [1.23-2.08], p = 0.0003 for the minor allele). Though nominally significant, these associations did not remain significant after correction for multiple hypothesis testing.ConclusionsTo our knowledge, with respect to sample size and scope of evaluation of candidate polymorphisms, this is the largest NTD genetic association study reported to date. The scale of the study and the

Evaluation of common genetic variants in 82 candidate genes as risk factors for neural tube defects

Directory of Open Access Journals (Sweden)

Pangilinan Faith

2012-08-01

Full Text Available Abstract Background Neural tube defects (NTDs are common birth defects (~1 in 1000 pregnancies in the US and Europe that have complex origins, including environmental and genetic factors. A low level of maternal folate is one well-established risk factor, with maternal periconceptional folic acid supplementation reducing the occurrence of NTD pregnancies by 50-70%. Gene variants in the folate metabolic pathway (e.g., MTHFR rs1801133 (677 C > T and MTHFD1 rs2236225 (R653Q have been found to increase NTD risk. We hypothesized that variants in additional folate/B12 pathway genes contribute to NTD risk. Methods A tagSNP approach was used to screen common variation in 82 candidate genes selected from the folate/B12 pathway and NTD mouse models. We initially genotyped polymorphisms in 320 Irish triads (NTD cases and their parents, including 301 cases and 341 Irish controls to perform case–control and family based association tests. Significantly associated polymorphisms were genotyped in a secondary set of 250 families that included 229 cases and 658 controls. The combined results for 1441 SNPs were used in a joint analysis to test for case and maternal effects. Results Nearly 70 SNPs in 30 genes were found to be associated with NTDs at the p MFTC, CDKN2A, ADA, PEMT, CUBN, GART, DNMT3A, MTHFD1 and T (Brachyury and included the known NTD risk factor MTHFD1 R653Q (rs2236225. The single strongest signal was observed in a new candidate, MFTC rs17803441 (OR = 1.61 [1.23-2.08], p = 0.0003 for the minor allele. Though nominally significant, these associations did not remain significant after correction for multiple hypothesis testing. Conclusions To our knowledge, with respect to sample size and scope of evaluation of candidate polymorphisms, this is the largest NTD genetic association study reported to date. The scale of the study and the stringency of correction are likely to have contributed to real associations failing to survive

Influence of neutrophil defects on Burkholderia cepacia complex pathogenesis

Directory of Open Access Journals (Sweden)

Laura A. Porter

2011-11-01

Full Text Available The Burkholderia cepacia complex (Bcc is a group of Gram-negative bacteria that are ubiquitous in the environment and have emerged as opportunistic pathogens in immunocompromised patients. The primary patient populations infected with Bcc include individuals with cystic fibrosis (CF, as well as those with chronic granulomatous disease (CGD. While Bcc infection in CF is better characterized than in CGD, these two genetic diseases are not obviously similar and it is currently unknown if there is any commonality in host immune defects that is responsible for the susceptibility to Bcc. CF is caused by mutations in the CF transmembrane conductance regulator, resulting in manifestations in various organ systems, however the major cause of morbidity and mortality is currently due to bacterial respiratory infections. CGD, on the other hand, is a genetic disorder that is caused by defects in phagocyte NADPH oxidase. Because of the defect in CGD, phagocytes in these patients are unable to produce reactive oxygen species, which results in increased susceptibility to bacterial and fungal infections. Despite this significant defect in microbial clearance, the spectrum of pathogens frequently implicated in infections in CGD is relatively narrow and includes some bacterial species that are considered almost pathognomonic for this disorder. Very little is known about the cause of the specific susceptibility to Bcc over other potential pathogens more prevalent in the environment, and a better understanding of specific mechanisms required for bacterial virulence has become a high priority. This review will summarize both the current knowledge and future directions related to Bcc virulence in immunocompromised individuals with a focus on the roles of bacterial factors and neutrophil defects in pathogenesis.

Epithelium-Derived Wnt Ligands Are Essential for Maintenance of Underlying Digit Bone.

Science.gov (United States)

Takeo, Makoto; Hale, Christopher S; Ito, Mayumi

2016-07-01

Clinically, many nail disorders accompany bone deformities, but whether the two defects are causally related is under debate. To investigate the potential interactions between the two tissue types, we analyzed epithelial-specific β-catenin-deficient mice, in which nail differentiation is abrogated. These mice showed regression of not only the nail plate but also of the underlying digit bone. Characterization of these bone defects revealed active bone resorption, which is suppressed by Wnt activation in osteoblast and osteoclast precursors. Furthermore, we found that Wntless expression, essential for Wnt ligand secretion, was lacking in the β-catenin-deficient nail epithelium and that genetic deletion of Wntless (Wls) in the nail epithelium led to the lack of Wnt activation in osteoblast and osteoclast precursors and subsequently led to defective regression of the underlying digit bone. Together, these data show that epithelial Wnt ligands can ultimately regulate Wnt signaling in osteoblast and osteoclast precursors, known to regulate bone homeostasis. These results reveal a critical role for the nail epithelium on the digit bone during homeostatic regeneration and show that Wnt/β-catenin signaling is critical for this interaction. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Monte-Carlo simulation of the evolution of point defects in solids under non-equilibrium conditions

International Nuclear Information System (INIS)

Maurice, Francoise; Doan, N.V.

1981-11-01

This report was written in order to serve as a guide for courageous users who want to tackle the problem of the evolution of point defect populations in a solid under non-equilibrium conditions by the Monte-Carlo technique. The original program, developed by Lanore in her swelling investigations on solids under irradiation by different particles, was generalized in order to take into account the effects and the phenomena related to the presence of solute atoms. Detailed descriptions of the simulation model, computational procedures and formulae used in the calculations are given. Two examples are shown to illustrate the applications to the swelling phenomenon: first, the effect to temperature or dose rate changes on void-swelling in electron-irradiated copper; second, the influence of solute atoms on the void nucleation in electron-irradiated nickel [fr

Defect assessment procedures at high temperature

International Nuclear Information System (INIS)

Ainsworth, R.A.

1991-01-01

A comprehensive assessment procedure for the high-temperature response of structures is being produced. The procedure is referred to as R5 and is written as a series of step-by-step instructions in a number of volumes. This paper considers in detail those parts of R5 which address the behaviour of defects. The defect assessment procedures may be applied to defects found in service, postulated defects, or defects formed during operation as a result of creep-fatigue loading. In the last case, a method is described for deducing from endurance data the number of cycles to initiate a crack of a specified size. Under steady loading, the creep crack tip parameter C * is used to assess crack growth. Under cyclic loading, the creep crack growth during dwell periods is stiell governed by C * but crack growth due to cyclic excursions must also be included. This cyclic crack growth is described by an effective stress intensity factor range. A feature of the R5 defect assessment procedures in that they are based on simplified methods and approximate reference stress methods are described which enable C * in a component to be evaluated. It is shown by comparison with theoretical calculations and experimental data that reliable estimates of C * and the associated crack growth are obtained provided realistic creep strain rate date are used in the reference stress approximation. (orig./HP)

Genetic Adaptation to Growth Under Laboratory Conditions in Escherichia coli and Salmonella enterica

Directory of Open Access Journals (Sweden)

Anna Knöppel

2018-04-01

Full Text Available Experimental evolution under controlled laboratory conditions is becoming increasingly important to address various evolutionary questions, including, for example, the dynamics and mechanisms of genetic adaptation to different growth and stress conditions. In such experiments, mutations typically appear that increase the fitness under the conditions tested (medium adaptation, but that are not necessarily of interest for the specific research question. Here, we have identified mutations that appeared during serial passage of E. coli and S. enterica in four different and commonly used laboratory media and measured the relative competitive fitness and maximum growth rate of 111 genetically re-constituted strains, carrying different single and multiple mutations. Little overlap was found between the mutations that were selected in the two species and the different media, implying that adaptation occurs via different genetic pathways. Furthermore, we show that commonly occurring adaptive mutations can generate undesired genetic variation in a population and reduce the accuracy of competition experiments. However, by introducing media adaptation mutations with large effects into the parental strain that was used for the evolution experiment, the variation (standard deviation was decreased 10-fold, and it was possible to measure fitness differences between two competitors as small as |s| < 0.001.

Novel genetic loci underlying human intracranial volume identified through genome-wide association

Science.gov (United States)

Adams, Hieab HH; Hibar, Derrek P; Chouraki, Vincent; Stein, Jason L; Nyquist, Paul A; Rentería, Miguel E; Trompet, Stella; Arias-Vasquez, Alejandro; Seshadri, Sudha; Desrivières, Sylvane; Beecham, Ashley H; Jahanshad, Neda; Wittfeld, Katharina; Van der Lee, Sven J; Abramovic, Lucija; Alhusaini, Saud; Amin, Najaf; Andersson, Micael; Arfanakis, Konstantinos; Aribisala, Benjamin S; Armstrong, Nicola J; Athanasiu, Lavinia; Axelsson, Tomas; Beiser, Alexa; Bernard, Manon; Bis, Joshua C; Blanken, Laura ME; Blanton, Susan H; Bohlken, Marc M; Boks, Marco P; Bralten, Janita; Brickman, Adam M; Carmichael, Owen; Chakravarty, M Mallar; Chauhan, Ganesh; Chen, Qiang; Ching, Christopher RK; Cuellar-Partida, Gabriel; Den Braber, Anouk; Doan, Nhat Trung; Ehrlich, Stefan; Filippi, Irina; Ge, Tian; Giddaluru, Sudheer; Goldman, Aaron L; Gottesman, Rebecca F; Greven, Corina U; Grimm, Oliver; Griswold, Michael E; Guadalupe, Tulio; Hass, Johanna; Haukvik, Unn K; Hilal, Saima; Hofer, Edith; Hoehn, David; Holmes, Avram J; Hoogman, Martine; Janowitz, Deborah; Jia, Tianye; Kasperaviciute, Dalia; Kim, Sungeun; Klein, Marieke; Kraemer, Bernd; Lee, Phil H; Liao, Jiemin; Liewald, David CM; Lopez, Lorna M; Luciano, Michelle; Macare, Christine; Marquand, Andre; Matarin, Mar; Mather, Karen A; Mattheisen, Manuel; Mazoyer, Bernard; McKay, David R; McWhirter, Rebekah; Milaneschi, Yuri; Mirza-Schreiber, Nazanin; Muetzel, Ryan L; Maniega, Susana Muñoz; Nho, Kwangsik; Nugent, Allison C; Olde Loohuis, Loes M; Oosterlaan, Jaap; Papmeyer, Martina; Pappa, Irene; Pirpamer, Lukas; Pudas, Sara; Pütz, Benno; Rajan, Kumar B; Ramasamy, Adaikalavan; Richards, Jennifer S; Risacher, Shannon L; Roiz-Santiañez, Roberto; Rommelse, Nanda; Rose, Emma J; Royle, Natalie A; Rundek, Tatjana; Sämann, Philipp G; Satizabal, Claudia L; Schmaal, Lianne; Schork, Andrew J; Shen, Li; Shin, Jean; Shumskaya, Elena; Smith, Albert V; Sprooten, Emma; Strike, Lachlan T; Teumer, Alexander; Thomson, Russell; Tordesillas-Gutierrez, Diana; Toro, Roberto; Trabzuni, Daniah; Vaidya, Dhananjay; Van der Grond, Jeroen; Van der Meer, Dennis; Van Donkelaar, Marjolein MJ; Van Eijk, Kristel R; Van Erp, Theo GM; Van Rooij, Daan; Walton, Esther; Westlye, Lars T; Whelan, Christopher D; Windham, Beverly G; Winkler, Anderson M; Woldehawariat, Girma; Wolf, Christiane; Wolfers, Thomas; Xu, Bing; Yanek, Lisa R; Yang, Jingyun; Zijdenbos, Alex; Zwiers, Marcel P; Agartz, Ingrid; Aggarwal, Neelum T; Almasy, Laura; Ames, David; Amouyel, Philippe; Andreassen, Ole A; Arepalli, Sampath; Assareh, Amelia A; Barral, Sandra; Bastin, Mark E; Becker, Diane M; Becker, James T; Bennett, David A; Blangero, John; van Bokhoven, Hans; Boomsma, Dorret I; Brodaty, Henry; Brouwer, Rachel M; Brunner, Han G; Buckner, Randy L; Buitelaar, Jan K; Bulayeva, Kazima B; Cahn, Wiepke; Calhoun, Vince D; Cannon, Dara M; Cavalleri, Gianpiero L; Chen, Christopher; Cheng, Ching-Yu; Cichon, Sven; Cookson, Mark R; Corvin, Aiden; Crespo-Facorro, Benedicto; Curran, Joanne E; Czisch, Michael; Dale, Anders M; Davies, Gareth E; De Geus, Eco JC; De Jager, Philip L; de Zubicaray, Greig I; Delanty, Norman; Depondt, Chantal; DeStefano, Anita L; Dillman, Allissa; Djurovic, Srdjan; Donohoe, Gary; Drevets, Wayne C; Duggirala, Ravi; Dyer, Thomas D; Erk, Susanne; Espeseth, Thomas; Evans, Denis A; Fedko, Iryna O; Fernández, Guillén; Ferrucci, Luigi; Fisher, Simon E; Fleischman, Debra A; Ford, Ian; Foroud, Tatiana M; Fox, Peter T; Francks, Clyde; Fukunaga, Masaki; Gibbs, J Raphael; Glahn, David C; Gollub, Randy L; Göring, Harald HH; Grabe, Hans J; Green, Robert C; Gruber, Oliver; Gudnason, Vilmundur; Guelfi, Sebastian; Hansell, Narelle K; Hardy, John; Hartman, Catharina A; Hashimoto, Ryota; Hegenscheid, Katrin; Heinz, Andreas; Le Hellard, Stephanie; Hernandez, Dena G; Heslenfeld, Dirk J; Ho, Beng-Choon; Hoekstra, Pieter J; Hoffmann, Wolfgang; Hofman, Albert; Holsboer, Florian; Homuth, Georg; Hosten, Norbert; Hottenga, Jouke-Jan; Hulshoff Pol, Hilleke E; Ikeda, Masashi; Ikram, M Kamran; Jack, Clifford R; Jenkinson, Mark; Johnson, Robert; Jönsson, Erik G; Jukema, J Wouter; Kahn, René S; Kanai, Ryota; Kloszewska, Iwona; Knopman, David S; Kochunov, Peter; Kwok, John B; Lawrie, Stephen M; Lemaître, Hervé; Liu, Xinmin; Longo, Dan L; Longstreth, WT; Lopez, Oscar L; Lovestone, Simon; Martinez, Oliver; Martinot, Jean-Luc; Mattay, Venkata S; McDonald, Colm; McIntosh, Andrew M; McMahon, Katie L; McMahon, Francis J; Mecocci, Patrizia; Melle, Ingrid; Meyer-Lindenberg, Andreas; Mohnke, Sebastian; Montgomery, Grant W; Morris, Derek W; Mosley, Thomas H; Mühleisen, Thomas W; Müller-Myhsok, Bertram; Nalls, Michael A; Nauck, Matthias; Nichols, Thomas E; Niessen, Wiro J; Nöthen, Markus M; Nyberg, Lars; Ohi, Kazutaka; Olvera, Rene L; Ophoff, Roel A; Pandolfo, Massimo; Paus, Tomas; Pausova, Zdenka; Penninx, Brenda WJH; Pike, G Bruce; Potkin, Steven G; Psaty, Bruce M; Reppermund, Simone; Rietschel, Marcella; Roffman, Joshua L; Romanczuk-Seiferth, Nina; Rotter, Jerome I; Ryten, Mina; Sacco, Ralph L; Sachdev, Perminder S; Saykin, Andrew J; Schmidt, Reinhold; Schofield, Peter R; Sigurdsson, Sigurdur; Simmons, Andy; Singleton, Andrew; Sisodiya, Sanjay M; Smith, Colin; Smoller, Jordan W; Soininen, Hilkka; Srikanth, Velandai; Steen, Vidar M; Stott, David J; Sussmann, Jessika E; Thalamuthu, Anbupalam; Tiemeier, Henning; Toga, Arthur W; Traynor, Bryan J; Troncoso, Juan; Turner, Jessica A; Tzourio, Christophe; Uitterlinden, Andre G; Valdés Hernández, Maria C; Van der Brug, Marcel; Van der Lugt, Aad; Van der Wee, Nic JA; Van Duijn, Cornelia M; Van Haren, Neeltje EM; Van 't Ent, Dennis; Van Tol, Marie-Jose; Vardarajan, Badri N; Veltman, Dick J; Vernooij, Meike W; Völzke, Henry; Walter, Henrik; Wardlaw, Joanna M; Wassink, Thomas H; Weale, Michael E; Weinberger, Daniel R; Weiner, Michael W; Wen, Wei; Westman, Eric; White, Tonya; Wong, Tien Y; Wright, Clinton B; Zielke, H Ronald; Zonderman, Alan B; Deary, Ian J; DeCarli, Charles; Schmidt, Helena; Martin, Nicholas G; De Craen, Anton JM; Wright, Margaret J; Launer, Lenore J; Schumann, Gunter; Fornage, Myriam; Franke, Barbara; Debette, Stéphanie; Medland, Sarah E; Ikram, M Arfan; Thompson, Paul M

2016-01-01

Intracranial volume reflects the maximally attained brain size during development, and remains stable with loss of tissue in late life. It is highly heritable, but the underlying genes remain largely undetermined. In a genome-wide association study of 32,438 adults, we discovered five novel loci for intracranial volume and confirmed two known signals. Four of the loci are also associated with adult human stature, but these remained associated with intracranial volume after adjusting for height. We found a high genetic correlation with child head circumference (ρgenetic=0.748), which indicated a similar genetic background and allowed for the identification of four additional loci through meta-analysis (Ncombined = 37,345). Variants for intracranial volume were also related to childhood and adult cognitive function, Parkinson’s disease, and enriched near genes involved in growth pathways including PI3K–AKT signaling. These findings identify biological underpinnings of intracranial volume and provide genetic support for theories on brain reserve and brain overgrowth. PMID:27694991

Mouse Models for Investigating the Developmental Bases of Human Birth Defects

OpenAIRE

MOON, ANNE M.

2006-01-01

Clinicians and basic scientists share an interest in discovering how genetic or environmental factors interact to perturb normal development and cause birth defects and human disease. Given the complexity of such interactions, it is not surprising that 4% of human infants are born with a congenital malformation, and cardiovascular defects occur in nearly 1%. Our research is based on the fundamental hypothesis that an understanding of normal and abnormal development will permit us to generate ...

The multiple genetic causes of central hypothyroidism.

Science.gov (United States)

Persani, Luca; Bonomi, Marco

2017-03-01

An insufficient stimulation by thyrotropin (TSH) of an otherwise normal thyroid gland represents the cause of Central Hypothyrodism (CeH). CeH is about 1000-folds rarer than Primary Hypothyroidism and often represents a real challenge for the clinicians, mainly because they cannot rely on adequately sensitive parameters for diagnosis or management, as it occurs with circulating TSH in PH. Therefore, CeH diagnosis can be frequently missed or delayed in patients with a previously unknown pituitary involvement. A series of genetic defects have been described to account for isolated CeH or combined pituitary hormone defects (CPHDs) with variable clinical characteristics and degrees of severity. The recently identified candidate gene IGSF1 appears frequently involved. This review provides an updated illustration of the different genetic defects accounting for CeH. Copyright © 2017 Elsevier Ltd. All rights reserved.

Embedded defects

International Nuclear Information System (INIS)

Barriola, M.; Vachaspati, T.; Bucher, M.

1994-01-01

We give a prescription for embedding classical solutions and, in particular, topological defects in field theories which are invariant under symmetry groups that are not necessarily simple. After providing examples of embedded defects in field theories based on simple groups, we consider the electroweak model and show that it contains the Z string and a one-parameter family of strings called the W(α) string. It is argued that although the members of this family are gauge equivalent when considered in isolation, each member becomes physically distinct when multistring configurations are considered. We then turn to the issue of stability of embedded defects and demonstrate the instability of a large class of such solutions in the absence of bound states or condensates. The Z string is shown to be unstable for all values of the Higgs boson mass when θ W =π/4. W strings are also shown to be unstable for a large range of parameters. Embedded monopoles suffer from the Brandt-Neri-Coleman instability. Finally, we connect the electroweak string solutions to the sphaleron

Nonhomologous Recombination between Defective Poliovirus and Coxsackievirus Genomes Suggests a New Model of Genetic Plasticity for Picornaviruses

Science.gov (United States)

Holmblat, Barbara; Jégouic, Sophie; Muslin, Claire; Blondel, Bruno; Joffret, Marie-Line

2014-01-01

ABSTRACT Most of the circulating vaccine-derived polioviruses (cVDPVs) implicated in poliomyelitis outbreaks in Madagascar have been shown to be recombinants between the type 2 poliovirus (PV) strain of the oral polio vaccine (Sabin 2) and another species C human enterovirus (HEV-C), such as type 17 coxsackie A virus (CA17) in particular. We studied intertypic genetic exchanges between PV and non-PV HEV-C by developing a recombination model, making it possible to rescue defective type 2 PV RNA genomes with a short deletion at the 3′ end by the cotransfection of cells with defective or infectious CA17 RNAs. We isolated over 200 different PV/CA17 recombinants, using murine cells expressing the human PV receptor (PVR) and selecting viruses with PV capsids. We found some homologous (H) recombinants and, mostly, nonhomologous (NH) recombinants presenting duplications of parental sequences preferentially located in the regions encoding proteins 2A, 2B, and 3A. Short duplications appeared to be stable, whereas longer duplications were excised during passaging in cultured cells or after multiplication in PVR-transgenic mice, generating H recombinants with diverse sites of recombination. This suggests that NH recombination events may be a transient, intermediate step in the generation and selection of the fittest H recombinants. In addition to the classical copy-choice mechanism of recombination thought to generate mostly H recombinants, there may also be a modular mechanism of recombination, involving NH recombinant precursors, shaping the genomes of recombinant enteroviruses and other picornaviruses. PMID:25096874

Indicators for Building Process without Final Defects -

DEFF Research Database (Denmark)

Jørgensen, Kirsten; Rasmussen, Grane Mikael Gregaard; Thuesen, Christian Langhoff

2011-01-01

This article introduces the preliminary data analysis, as well as the underlying theories and methods for identifying the indicators for building process without final defects. Since 2004, the Benchmark Centre for the Danish Construction Sector (BEC) has collected information about legal defects...

Genetics of intellectual disability in consanguineous families.

Science.gov (United States)

Hu, Hao; Kahrizi, Kimia; Musante, Luciana; Fattahi, Zohreh; Herwig, Ralf; Hosseini, Masoumeh; Oppitz, Cornelia; Abedini, Seyedeh Sedigheh; Suckow, Vanessa; Larti, Farzaneh; Beheshtian, Maryam; Lipkowitz, Bettina; Akhtarkhavari, Tara; Mehvari, Sepideh; Otto, Sabine; Mohseni, Marzieh; Arzhangi, Sanaz; Jamali, Payman; Mojahedi, Faezeh; Taghdiri, Maryam; Papari, Elaheh; Soltani Banavandi, Mohammad Javad; Akbari, Saeide; Tonekaboni, Seyed Hassan; Dehghani, Hossein; Ebrahimpour, Mohammad Reza; Bader, Ingrid; Davarnia, Behzad; Cohen, Monika; Khodaei, Hossein; Albrecht, Beate; Azimi, Sarah; Zirn, Birgit; Bastami, Milad; Wieczorek, Dagmar; Bahrami, Gholamreza; Keleman, Krystyna; Vahid, Leila Nouri; Tzschach, Andreas; Gärtner, Jutta; Gillessen-Kaesbach, Gabriele; Varaghchi, Jamileh Rezazadeh; Timmermann, Bernd; Pourfatemi, Fatemeh; Jankhah, Aria; Chen, Wei; Nikuei, Pooneh; Kalscheuer, Vera M; Oladnabi, Morteza; Wienker, Thomas F; Ropers, Hans-Hilger; Najmabadi, Hossein

2018-01-04

Autosomal recessive (AR) gene defects are the leading genetic cause of intellectual disability (ID) in countries with frequent parental consanguinity, which account for about 1/7th of the world population. Yet, compared to autosomal dominant de novo mutations, which are the predominant cause of ID in Western countries, the identification of AR-ID genes has lagged behind. Here, we report on whole exome and whole genome sequencing in 404 consanguineous predominantly Iranian families with two or more affected offspring. In 219 of these, we found likely causative variants, involving 77 known and 77 novel AR-ID (candidate) genes, 21 X-linked genes, as well as 9 genes previously implicated in diseases other than ID. This study, the largest of its kind published to date, illustrates that high-throughput DNA sequencing in consanguineous families is a superior strategy for elucidating the thousands of hitherto unknown gene defects underlying AR-ID, and it sheds light on their prevalence.

High Defect Tolerance in Lead Halide Perovskite CsPbBr3.

Science.gov (United States)

Kang, Jun; Wang, Lin-Wang

2017-01-19

The formation energies and charge-transition levels of intrinsic point defects in lead halide perovskite CsPbBr 3 are studied from first-principles calculations. It is shown that the formation energy of dominant defect under Br-rich growth condition is much lower than that under moderate or Br-poor conditions. Thus avoiding the Br-rich condition can help to reduce the defect concentration. Interestingly, CsPbBr 3 is found to be highly defect-tolerant in terms of its electronic structure. Most of the intrinsic defects induce shallow transition levels. Only a few defects with high formation energies can create deep transition levels. Therefore, CsPbBr 3 can maintain its good electronic quality despite the presence of defects. Such defect tolerance feature can be attributed to the lacking of bonding-antibonding interaction between the conduction bands and valence bands.

Genetic diversity and distribution of Senegalia senegal (L.) Britton under climate change scenarios in West Africa

Science.gov (United States)

Duque-Lazo, Joaquín; Durka, Walter; Hauenschild, Frank; Schnitzler, Jan; Michalak, Ingo; Ogundipe, Oluwatoyin Temitayo; Muellner-Riehl, Alexandra Nora

2018-01-01

Climate change is predicted to impact species’ genetic diversity and distribution. We used Senegalia senegal (L.) Britton, an economically important species distributed in the Sudano-Sahelian savannah belt of West Africa, to investigate the impact of climate change on intraspecific genetic diversity and distribution. We used ten nuclear and two plastid microsatellite markers to assess genetic variation, population structure and differentiation across thirteen sites in West Africa. We projected suitable range, and potential impact of climate change on genetic diversity using a maximum entropy approach, under four different climate change scenarios. We found higher genetic and haplotype diversity at both nuclear and plastid markers than previously reported. Genetic differentiation was strong for chloroplast and moderate for the nuclear genome. Both genomes indicated three spatially structured genetic groups. The distribution of Senegalia senegal is strongly correlated with extractable nitrogen, coarse fragments, soil organic carbon stock, precipitation of warmest and coldest quarter and mean temperature of driest quarter. We predicted 40.96 to 6.34 per cent of the current distribution to favourably support the species’ ecological requirements under future climate scenarios. Our results suggest that climate change is going to affect the population genetic structure of Senegalia senegal, and that patterns of genetic diversity are going to influence the species’ adaptive response to climate change. Our study contributes to the growing evidence predicting the loss of economically relevant plants in West Africa in the next decades due to climate change. PMID:29659603

A defect in the TUSC3 gene is associated with autosomal recessive mental retardation.

Science.gov (United States)

Garshasbi, Masoud; Hadavi, Valeh; Habibi, Haleh; Kahrizi, Kimia; Kariminejad, Roxana; Behjati, Farkhondeh; Tzschach, Andreas; Najmabadi, Hossein; Ropers, Hans Hilger; Kuss, Andreas Walter

2008-05-01

Recent studies have shown that autosomal recessive mental retardation (ARMR) is extremely heterogeneous, and there is reason to believe that the number of underlying gene defects goes into the thousands. To date, however, only four genes have been implicated in nonsyndromic ARMR (NS-ARMR): PRSS12 (neurotrypsin), CRBN (cereblon), CC2D1A, and GRIK2. As part of an ongoing systematic study aiming to identify ARMR genes, we investigated a large consanguineous family comprising seven patients with nonsyndromic ARMR in four sibships. Genome-wide SNP typing enabled us to map the relevant genetic defect to a 4.6 Mbp interval on chromosome 8. Haplotype analyses and copy-number studies led to the identification of a homozygous deletion partly removing TUSC3 (N33) in all patients. All obligate carriers of this family were heterozygous, but none of 192 unrelated healthy individuals from the same population carried this deletion. We excluded other disease-causing mutations in the coding regions of all genes within the linkage interval by sequencing; moreover, we verified the complete absence of a functional TUSC3 transcript in all patients through RT-PCR. TUSC3 is thought to encode a subunit of the endoplasmic reticulum-bound oligosaccharyltransferase complex that catalyzes a pivotal step in the protein N-glycosylation process. Our data suggest that in contrast to other genetic defects of glycosylation, inactivation of TUSC3 causes nonsyndromic MR, a conclusion that is supported by a separate report in this issue of AJHG. TUSC3 is only the fifth gene implicated in NS-ARMR and the first for which mutations have been reported in more than one family.

Multiscale crystal defect dynamics: A coarse-grained lattice defect model based on crystal microstructure

Science.gov (United States)

Lyu, Dandan; Li, Shaofan

2017-10-01

Crystal defects have microstructure, and this microstructure should be related to the microstructure of the original crystal. Hence each type of crystals may have similar defects due to the same failure mechanism originated from the same microstructure, if they are under the same loading conditions. In this work, we propose a multiscale crystal defect dynamics (MCDD) model that models defects by considering its intrinsic microstructure derived from the microstructure or material genome of the original perfect crystal. The main novelties of present work are: (1) the discrete exterior calculus and algebraic topology theory are used to construct a scale-up (coarse-grained) dual lattice model for crystal defects, which may represent all possible defect modes inside a crystal; (2) a higher order Cauchy-Born rule (up to the fourth order) is adopted to construct atomistic-informed constitutive relations for various defect process zones, and (3) an hierarchical strain gradient theory based finite element formulation is developed to support an hierarchical multiscale cohesive (process) zone model for various defects in a unified formulation. The efficiency of MCDD computational algorithm allows us to simulate dynamic defect evolution at large scale while taking into account atomistic interaction. The MCDD model has been validated by comparing of the results of MCDD simulations with that of molecular dynamics (MD) in the cases of nanoindentation and uniaxial tension. Numerical simulations have shown that MCDD model can predict dislocation nucleation induced instability and inelastic deformation, and thus it may provide an alternative solution to study crystal plasticity.

Nuclear genetic defects of mitochondrial ATP synthase

Czech Academy of Sciences Publication Activity Database

Hejzlarová, Kateřina; Mráček, Tomáš; Vrbacký, Marek; Kaplanová, Vilma; Karbanová, Vendula; Nůsková, Hana; Pecina, Petr; Houštěk, Josef

2014-01-01

Roč. 63, Suppl.1 (2014), S57-S71 ISSN 0862-8408 R&D Projects: GA ČR(CZ) GAP303/11/0970; GA ČR GAP303/12/1363; GA MZd(CZ) NT12370; GA MZd(CZ) NT14050 Grant - others:Univerzita Karlova(CZ) 370411 Institutional support: RVO:67985823 Keywords : mitochondrial diseases * TMEM70 * ATPAF1 * ATP5A1 * ATP5E Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.293, year: 2014

The Congenital Heart Disease Genetic Network Study: Cohort description.

Directory of Open Access Journals (Sweden)

Thanh T Hoang

Full Text Available The Pediatric Cardiac Genomics Consortium (PCGC designed the Congenital Heart Disease Genetic Network Study to provide phenotype and genotype data for a large congenital heart defects (CHDs cohort. This article describes the PCGC cohort, overall and by major types of CHDs (e.g., conotruncal defects and subtypes of conotrucal heart defects (e.g., tetralogy of Fallot and left ventricular outflow tract obstructions (e.g., hypoplastic left heart syndrome. Cases with CHDs were recruited through ten sites, 2010-2014. Information on cases (N = 9,727 and their parents was collected through interviews and medical record abstraction. Four case characteristics, eleven parental characteristics, and thirteen parent-reported neurodevelopment outcomes were summarized using counts and frequencies and compared across CHD types and subtypes. Eleven percent of cases had a genetic diagnosis. Among cases without a genetic diagnosis, the majority had conotruncal heart defects (40% or left ventricular outflow tract obstruction (21%. Across CHD types, there were significant differences (p<0.05 in the distribution of all four case characteristics (e.g., sex, four parental characteristics (e.g., maternal pregestational diabetes, and five neurodevelopmental outcomes (e.g., learning disabilities. Several characteristics (e.g., sex were also significantly different across CHD subtypes. The PCGC cohort is one of the largest CHD cohorts available for the study of genetic determinants of risk and outcomes. The majority of cases do not have a genetic diagnosis. This description of the PCGC cohort, including differences across CHD types and subtypes, provides a reference work for investigators who are interested in collaborating with or using publically available resources from the PCGC.

Non-electron transfer chain mitochondrial defects differently regulate HIF-1α degradation and transcription

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Antonina N. Shvetsova

2017-08-01

Full Text Available Mitochondria are the main consumers of molecular O2 in a cell as well as an abundant source of reactive oxygen species (ROS. Both, molecular oxygen and ROS are powerful regulators of the hypoxia-inducible factor-1α-subunit (HIF-α. While a number of mechanisms in the oxygen-dependent HIF-α regulation are quite well known, the view with respect to mitochondria is less clear. Several approaches using pharmacological or genetic tools targeting the mitochondrial electron transport chain (ETC indicated that ROS, mainly formed at the Rieske cluster of complex III of the ETC, are drivers of HIF-1α activation. However, studies investigating non-ETC located mitochondrial defects and their effects on HIF-1α regulation are scarce, if at all existing. Thus, in the present study we examined three cell lines with non-ETC mitochondrial defects and focused on HIF-1α degradation and transcription, target gene expression, as well as ROS levels. We found that cells lacking the key enzyme 2-enoyl thioester reductase/mitochondrial enoyl-CoA reductase (MECR, and cells lacking manganese superoxide dismutase (MnSOD showed a reduced induction of HIF-1α under long-term (20 h hypoxia. By contrast, cells lacking the mitochondrial DNA depletion syndrome channel protein Mpv17 displayed enhanced levels of HIF-1α already under normoxic conditions. Further, we show that ROS do not exert a uniform pattern when mediating their effects on HIF-1α, although all mitochondrial defects in the used cell types increased ROS formation. Moreover, all defects caused a different HIF-1α regulation via promoting HIF-1α degradation as well as via changes in HIF-1α transcription. Thereby, MECR- and MnSOD-deficient cells showed a reduction in HIF-1α mRNA levels whereas the Mpv17 lacking cells displayed enhanced HIF-1α mRNA levels under normoxia and hypoxia. Altogether, our study shows for the first time that mitochondrial defects which are not related to the ETC and Krebs cycle

Effect of noise on defect chaos in a reaction-diffusion model.

Science.gov (United States)

Wang, Hongli; Ouyang, Qi

2005-06-01

The influence of noise on defect chaos due to breakup of spiral waves through Doppler and Eckhaus instabilities is investigated numerically with a modified Fitzhugh-Nagumo model. By numerical simulations we show that the noise can drastically enhance the creation and annihilation rates of topological defects. The noise-free probability distribution function for defects in this model is found not to fit with the previously reported squared-Poisson distribution. Under the influence of noise, the distributions are flattened, and can fit with the squared-Poisson or the modified-Poisson distribution. The defect lifetime and diffusive property of defects under the influence of noise are also checked in this model.

New insights into the genetic basis of infertility

Directory of Open Access Journals (Sweden)

Venkatesh T

2014-12-01

Full Text Available Thejaswini Venkatesh,1 Padmanaban S Suresh,2 Rie Tsutsumi3 1Institute for Stem Cell Biology and Regenerative Medicine, National Centre for Biological Sciences, Bangalore, 2Centre for Biomedical Research, VIT University, Vellore, India; 3University of Tokushima, Institute of Health Bioscience, Department of Public Health and Nutrition, Tokushima, Japan Abstract: Infertility is a disease of the reproductive system characterized by inability to achieve pregnancy after 12 or more months of regular unprotected sexual intercourse. A variety of factors, including ovulation defects, spermatogenic failure, parental age, obesity, and infections have been linked with infertility, in addition to specific karyotypes and genotypes. The study of genes associated with infertility in rodent models has expanded the field of translational genetics in identifying the underlying cause of human infertility problems. Many intriguing aspects of the molecular basis of infertility in humans remain poorly understood; however, application of genetic knowledge in this field looks promising. The growing literature on the genetics of human infertility disorders deserves attention and a critical concise summary is required. This paper provides information obtained from a systematic analysis of the literature related to current research into the genetics of infertility affecting both sexes. Keywords: infertility, genetics, polycystic ovary syndrome, premature ovarian failure, spermatogenic failure, cystic fibrosis

The genetics of hair-cell function in zebrafish.

Science.gov (United States)

Nicolson, Teresa

2017-09-01

Our ears are remarkable sensory organs, providing the important senses of balance and hearing. The complex structure of the inner ear, or 'labyrinth', along with the assorted neuroepithelia, have evolved to detect head movements and sounds with impressive sensitivity. The rub is that the inner ear is highly vulnerable to genetic lesions and environmental insults. According to National Institute of Health estimates, hearing loss is one of the most commonly inherited or acquired sensorineural diseases. To understand the causes of deafness and balance disorders, it is imperative to understand the underlying biology of the inner ear, especially the inner workings of the sensory receptors. These receptors, which are termed hair cells, are particularly susceptible to genetic mutations - more than two dozen genes are associated with defects in this cell type in humans. Over the past decade, a substantial amount of progress has been made in working out the molecular basis of hair-cell function using vertebrate animal models. Given the transparency of the inner ear and the genetic tools that are available, zebrafish have become an increasingly popular animal model for the study of deafness and vestibular dysfunction. Mutagenesis screens for larval defects in hearing and balance have been fruitful in finding key components, many of which have been implicated in human deafness. This review will focus on the genes that are required for hair-cell function in zebrafish, with a particular emphasis on mechanotransduction. In addition, the generation of new tools available for the characterization of zebrafish hair-cell mutants will be discussed.

Germline cytotoxic lymphocytes defective mutations in Chinese patients with lymphoma

OpenAIRE

Chen, Xue; Zhang, Yang; Wang, Fang; Wang, Mangju; Teng, Wen; Lin, Yuehui; Han, Xiangping; Jin, Fangyuan; Xu, Yuanli; Cao, Panxiang; Fang, Jiancheng; Zhu, Ping; Tong, Chunrong; Liu, Hongxing

2017-01-01

Certain patients with lymphoma may harbor mutations in perforin 1 (PRF1), unc-13 homolog D (UNC13D), syntaxin 11 (STX11), STXBP2 (syntaxin binding protein 2) or SH2 domain containing 1A (SH2D1A), which causes functional defects of cytotoxic lymphocytes. Data regarding the association between genetic defects and the development of lymphoma in Chinese patients are limited to date. In the present study, 90 patients with lymphoma were analyzed for UNC13D, PRF1, STXBP2, STX11, SH2D1A and X-linked ...

More than a bystander: the contributions of intrinsic skeletal muscle defects in motor neuron diseases.

Science.gov (United States)

Boyer, Justin G; Ferrier, Andrew; Kothary, Rashmi

2013-12-18

Spinal muscular atrophy (SMA), amyotrophic lateral sclerosis (ALS), and spinal-bulbar muscular atrophy (SBMA) are devastating diseases characterized by the degeneration of motor neurons. Although the molecular causes underlying these diseases differ, recent findings have highlighted the contribution of intrinsic skeletal muscle defects in motor neuron diseases. The use of cell culture and animal models has led to the important finding that muscle defects occur prior to and independently of motor neuron degeneration in motor neuron diseases. In SMA for instance, the muscle specific requirements of the SMA disease-causing gene have been demonstrated by a series of genetic rescue experiments in SMA models. Conditional ALS mouse models expressing a muscle specific mutant SOD1 gene develop atrophy and muscle degeneration in the absence of motor neuron pathology. Treating SBMA mice by over-expressing IGF-1 in a skeletal muscle-specific manner attenuates disease severity and improves motor neuron pathology. In the present review, we provide an in depth description of muscle intrinsic defects, and discuss how they impact muscle function in these diseases. Furthermore, we discuss muscle-specific therapeutic strategies used to treat animal models of SMA, ALS, and SBMA. The study of intrinsic skeletal muscle defects is crucial for the understanding of the pathophysiology of these diseases and will open new therapeutic options for the treatment of motor neuron diseases.

Genetics Home Reference: X-linked immunodeficiency with magnesium defect, Epstein-Barr virus infection, and neoplasia

Science.gov (United States)

... Conditions XMEN X-linked immunodeficiency with magnesium defect, Epstein-Barr virus infection, and neoplasia Printable PDF Open All Close ... boxes. Description X-linked immunodeficiency with magnesium defect, Epstein-Barr virus infection, and neoplasia (typically known by the acronym ...

Genetics of Congenital Heart Disease: Past and Present.

Science.gov (United States)

Muntean, Iolanda; Togănel, Rodica; Benedek, Theodora

2017-04-01

Congenital heart disease is the most common congenital anomaly, representing an important cause of infant morbidity and mortality. Congenital heart disease represents a group of heart anomalies that include septal defects, valve defects, and outflow tract anomalies. The exact genetic, epigenetic, or environmental basis of congenital heart disease remains poorly understood, although the exact mechanism is likely multifactorial. However, the development of new technologies including copy number variants, single-nucleotide polymorphism, next-generation sequencing are accelerating the detection of genetic causes of heart anomalies. Recent studies suggest a role of small non-coding RNAs, micro RNA, in congenital heart disease. The recently described epigenetic factors have also been found to contribute to cardiac morphogenesis. In this review, we present past and recent genetic discoveries in congenital heart disease.

Cognitive mechanisms underlying disorganization of thought in a genetic syndrome (47,XXY)

NARCIS (Netherlands)

Van Rijn, Sophie; Aleman, Andre; De Sonneville, Leo; Swaab, Hanna

Because of the risk for development of psychopathology such as psychotic symptoms, it has been suggested that studying men with the XXY karyotype may help in the search for underlying cognitive, neural and genetic mechanisms. The aim of this study was to identify cognitive mechanisms that may

Genetic activity of plant growth regulators, cartolin and benzilandenin, under ionizing radiation

International Nuclear Information System (INIS)

Vilenskij, E.P.

1987-01-01

Protective effects of a new cytokinin-type growth regulator cartolin (CRT) are established on a genetic test system of waxy-changes in pollen barley grains under acute irradiation of growing plants. It is shown that the CRT effect is similar to that of synthetic cytokinin benziladenin

Defects of diamond single crystal grown under high temperature and high pressure

Energy Technology Data Exchange (ETDEWEB)

Su, Qingcai, E-mail: suqc@sdu.edu.cn [Key Laboratory of Liquid Structure and Heredity of Materials (Ministry of Education), Shandong University, Jinan, P. R. China, 250061 (China); School of Materials Science and Engineering, Shandong University, Jinan, P. R. China, 250061 (China); Shandong Engineering Research Center for Superhard Materials, Zoucheng, P. R. China 273500 (China); Zhang, Jianhua [School of Mechanical Engineering, Shandong University, Jinan, P. R. China, 250061 (China); Li, Musen [Key Laboratory of Liquid Structure and Heredity of Materials (Ministry of Education), Shandong University, Jinan, P. R. China, 250061 (China); School of Materials Science and Engineering, Shandong University, Jinan, P. R. China, 250061 (China); Shandong Engineering Research Center for Superhard Materials, Zoucheng, P. R. China 273500 (China)

2013-11-01

The diamond single crystal, synthesized with Fe–Ni–C–B system of catalyst under high temperature and high pressure, had been observed by field emission scanning electron microscope and transmission electron microscope. The presence of a cellular structure suggested that the diamond grew from melted catalyst solution and there existed a zone of component supercooling zone in front of the solid–liquid interface. The main impurities in the diamond crystal was (FeNi){sub 23}C{sub 6}. The triangle screw pit revealed on the (111) plane was generated by the screw dislocation meeting the diamond (111) plane at the points of emergence of dislocations. A narrow twin plane was formed between the two (111) plane. - Highlights: • High pressure, high temperature synthesis of diamond single crystal. • Fe–Ni–C–B used as catalyst, graphite as carbon source. • The main impurity in the diamond crystal was (FeNi){sub 23}C{sub 6}. • Surface defects arose from screw dislocations and stacking faults.

Defects and defect processes in nonmetallic solids

CERN Document Server

Hayes, W

2004-01-01

This extensive survey covers defects in nonmetals, emphasizing point defects and point-defect processes. It encompasses electronic, vibrational, and optical properties of defective solids, plus dislocations and grain boundaries. 1985 edition.

Study on the intrinsic defects in tin oxide with first-principles method

Science.gov (United States)

Sun, Yu; Liu, Tingyu; Chang, Qiuxiang; Ma, Changmin

2018-04-01

First-principles and thermodynamic methods are used to study the contribution of vibrational entropy to defect formation energy and the stability of the intrinsic point defects in SnO2 crystal. According to thermodynamic calculation results, the contribution of vibrational entropy to defect formation energy is significant and should not be neglected, especially at high temperatures. The calculated results indicate that the oxygen vacancy is the major point defect in undoped SnO2 crystal, which has a higher concentration than that of the other point defect. The property of negative-U is put forward in SnO2 crystal. In order to determine the most stable defects much clearer under different conditions, the most stable intrinsic defect as a function of Fermi level, oxygen partial pressure and temperature are described in the three-dimensional defect formation enthalpy diagrams. The diagram visually provides the most stable point defects under different conditions.

Positron lifetime calculation for defects and defect clusters in graphite

International Nuclear Information System (INIS)

Onitsuka, T.; Ohkubo, H.; Takenaka, M.; Tsukuda, N.; Kuramoto, E.

2000-01-01

Calculations of positron lifetime have been made for vacancy type defects in graphite and compared with experimental results. Defect structures were obtained in a model graphite lattice after including relaxation of whole lattice as determined by the molecular dynamics method, where the interatomic potential given by Pablo Andribet, Dominguez-Vazguez, Mari Carmen Perez-Martin, Alonso, Jimenez-Rodriguez [Nucl. Instrum. and Meth. 115 (1996) 501] was used. For the defect structures obtained via lattice relaxation positron lifetime was calculated under the so-called atomic superposition method. Positron lifetimes 204 and 222 ps were obtained for the graphite matrix and a single vacancy, respectively, which can be compared with the experimental results 208 and 233 ps. For planar vacancy clusters, e.g., vacancy loops, lifetime calculation was also made and indicated that lifetime increases with the number of vacancies in a cluster. This is consistent with the experimental result in the region of higher annealing temperature (above 1200 deg. C), where the increase of positron lifetime is seen, probably corresponding to the clustering of mobile vacancies

Dislocations and point defects in hydrostatically compressed crystal

International Nuclear Information System (INIS)

Kosevich, A.M.; Tokij, V.V.; Strel'tsov, V.A.

1978-01-01

Within the framework of the theory of finite deformations, the elastic fields are considered, which are induced by the sources of internal stresses in a crystal compressed under a high pressure. In the case of a hydrostatically compressed crystal with defects, the use of a variation principle is discussed. Using the smallness of distorsions, the linear theory of elastic fields of defects in the crystal compressed under a high pressure, is developed. An analysis of the main relationships of the theory results in the following conclusion: in a course of the linear approximation the taking into account of the hydrostatic pressure brings to the renorming of the elasticity moduli and to the replacing of the hydrostatic parameters of defects by their values in the compressed crystal. That conclusion allows the results of the elasticity linear theory of the crystal with defects to be used to the full extent

Journal of Genetics | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Genetics. Alpana Naresh. Articles written in Journal of Genetics. Volume 79 Issue 3 2000 pp 83-90. Identification of four genes involved in suppression of the pre-mRNA splicing defect in the sng1-1/rhp6 mutant of fission yeast · Alpana Naresh Jagmohan Singh · More Details Abstract Fulltext PDF.

Genome-wide association studies dissect the genetic networks underlying agronomical traits in soybean.

Science.gov (United States)

Fang, Chao; Ma, Yanming; Wu, Shiwen; Liu, Zhi; Wang, Zheng; Yang, Rui; Hu, Guanghui; Zhou, Zhengkui; Yu, Hong; Zhang, Min; Pan, Yi; Zhou, Guoan; Ren, Haixiang; Du, Weiguang; Yan, Hongrui; Wang, Yanping; Han, Dezhi; Shen, Yanting; Liu, Shulin; Liu, Tengfei; Zhang, Jixiang; Qin, Hao; Yuan, Jia; Yuan, Xiaohui; Kong, Fanjiang; Liu, Baohui; Li, Jiayang; Zhang, Zhiwu; Wang, Guodong; Zhu, Baoge; Tian, Zhixi

2017-08-24

Soybean (Glycine max [L.] Merr.) is one of the most important oil and protein crops. Ever-increasing soybean consumption necessitates the improvement of varieties for more efficient production. However, both correlations among different traits and genetic interactions among genes that affect a single trait pose a challenge to soybean breeding. To understand the genetic networks underlying phenotypic correlations, we collected 809 soybean accessions worldwide and phenotyped them for two years at three locations for 84 agronomic traits. Genome-wide association studies identified 245 significant genetic loci, among which 95 genetically interacted with other loci. We determined that 14 oil synthesis-related genes are responsible for fatty acid accumulation in soybean and function in line with an additive model. Network analyses demonstrated that 51 traits could be linked through the linkage disequilibrium of 115 associated loci and these links reflect phenotypic correlations. We revealed that 23 loci, including the known Dt1, E2, E1, Ln, Dt2, Fan, and Fap loci, as well as 16 undefined associated loci, have pleiotropic effects on different traits. This study provides insights into the genetic correlation among complex traits and will facilitate future soybean functional studies and breeding through molecular design.

Helium bubbles aggravated defects production in self-irradiated copper

Science.gov (United States)

Wu, FengChao; Zhu, YinBo; Wu, Qiang; Li, XinZhu; Wang, Pei; Wu, HengAn

2017-12-01

Under the environment of high radiation, materials used in fission and fusion reactors will internally accumulate numerous lattice defects and bubbles. With extensive studies focused on bubble resolution under irradiation, the mutually effects between helium bubbles and displacement cascades in irradiated materials remain unaddressed. Therefore, the defects production and microstructure evolution under self-irradiation events in vicinity of helium bubbles are investigated by preforming large scale molecular dynamics simulations in single-crystal copper. When subjected to displacement cascades, distinguished bubble resolution categories dependent on bubble size are observed. With the existence of bubbles, radiation damage is aggravated with the increasing bubble size, represented as the promotion of point defects and dislocations. The atomic mechanisms of heterogeneous dislocation structures are attributed to different helium-vacancy cluster modes, transforming from the resolved gas trapped with vacancies to the biased absorption of vacancies by the over-pressured bubble. In both cases, helium impedes the recombination of point defects, leading to the accelerated formation of interstitial loops. The results and insight obtained here might contribute to understand the underlying mechanism of transmutant solute on the long-term evolution of irradiated materials.

Whole Exome Sequencing Reveals Genetic Predisposition in a Large Family with Retinitis Pigmentosa

Directory of Open Access Journals (Sweden)

Juan Wu

2014-01-01

Full Text Available Next-generation sequencing has become more widely used to reveal genetic defect in monogenic disorders. Retinitis pigmentosa (RP, the leading cause of hereditary blindness worldwide, has been attributed to more than 67 disease-causing genes. Due to the extreme genetic heterogeneity, using general molecular screening alone is inadequate for identifying genetic predispositions in susceptible individuals. In order to identify underlying mutation rapidly, we utilized next-generation sequencing in a four-generation Chinese family with RP. Two affected patients and an unaffected sibling were subjected to whole exome sequencing. Through bioinformatics analysis and direct sequencing confirmation, we identified p.R135W transition in the rhodopsin gene. The mutation was subsequently confirmed to cosegregate with the disease in the family. In this study, our results suggest that whole exome sequencing is a robust method in diagnosing familial hereditary disease.

The molecular basis of hereditary enamel defects in humans.

Science.gov (United States)

Wright, J T; Carrion, I A; Morris, C

2015-01-01

The formation of human enamel is highly regulated at the molecular level and involves thousands of genes. Requisites for development of this highly mineralized tissue include cell differentiation; production of a unique extracellular matrix; processing of the extracellular matrix; altering of cell function during different stages of enamel formation; cell movement and attachment; regulation of ion and protein movement; and regulation of hydration, pH, and other conditions of the microenvironment, to name just a few. Not surprising, there is a plethora of hereditary conditions with an enamel phenotype. The objective of this review was to identify the hereditary conditions listed on Online Mendelian Inheritance in Man (OMIM) that have an associated enamel phenotype and whether a causative gene has been identified. The OMIM database was searched with the terms amelogenesis, enamel, dental, and tooth, and all results were screened by 2 individuals to determine if an enamel phenotype was identified. Gene and gene product function was reviewed on OMIM and from publications identified in PubMed. The search strategy revealed 91 conditions listed in OMIM as having an enamel phenotype, and of those, 71 have a known molecular etiology or linked genetic loci. The purported protein function of those conditions with a known genetic basis included enzymes, regulatory proteins, extracellular matrix proteins, transcription factors, and transmembrane proteins. The most common enamel phenotype was a deficient amount of enamel, or enamel hypoplasia, with hypomineralization defects being reported less frequently. Knowing these molecular defects allows an initial cataloging of molecular pathways that lead to hereditary enamel defects in humans. This knowledge provides insight into the diverse molecular pathways involved in enamel formation and can be useful when searching for the genetic etiology of hereditary conditions that involve enamel. © International & American Associations for

The Molecular Basis of Hereditary Enamel Defects in Humans

Science.gov (United States)

Carrion, I.A.; Morris, C.

2015-01-01

The formation of human enamel is highly regulated at the molecular level and involves thousands of genes. Requisites for development of this highly mineralized tissue include cell differentiation; production of a unique extracellular matrix; processing of the extracellular matrix; altering of cell function during different stages of enamel formation; cell movement and attachment; regulation of ion and protein movement; and regulation of hydration, pH, and other conditions of the microenvironment, to name just a few. Not surprising, there is a plethora of hereditary conditions with an enamel phenotype. The objective of this review was to identify the hereditary conditions listed on Online Mendelian Inheritance in Man (OMIM) that have an associated enamel phenotype and whether a causative gene has been identified. The OMIM database was searched with the terms amelogenesis, enamel, dental, and tooth, and all results were screened by 2 individuals to determine if an enamel phenotype was identified. Gene and gene product function was reviewed on OMIM and from publications identified in PubMed. The search strategy revealed 91 conditions listed in OMIM as having an enamel phenotype, and of those, 71 have a known molecular etiology or linked genetic loci. The purported protein function of those conditions with a known genetic basis included enzymes, regulatory proteins, extracellular matrix proteins, transcription factors, and transmembrane proteins. The most common enamel phenotype was a deficient amount of enamel, or enamel hypoplasia, with hypomineralization defects being reported less frequently. Knowing these molecular defects allows an initial cataloging of molecular pathways that lead to hereditary enamel defects in humans. This knowledge provides insight into the diverse molecular pathways involved in enamel formation and can be useful when searching for the genetic etiology of hereditary conditions that involve enamel. PMID:25389004

Shared activity patterns arising at genetic susceptibility loci reveal underlying genomic and cellular architecture of human disease

DEFF Research Database (Denmark)

Baillie, J Kenneth; Bretherick, Andrew; Haley, Christopher S

2018-01-01

Genetic variants underlying complex traits, including disease susceptibility, are enriched within the transcriptional regulatory elements, promoters and enhancers. There is emerging evidence that regulatory elements associated with particular traits or diseases share similar patterns...... the regulation of the OCT1 cation transporter and genetic variants underlying circulating cholesterol levels. NDA strongly implicates particular cell types and tissues in disease pathogenesis. For example, distinct groupings of disease-associated regulatory regions implicate two distinct biological processes...... in the pathogenesis of ulcerative colitis; a further two separate processes are implicated in Crohn's disease. Thus, our functional analysis of genetic predisposition to disease defines new distinct disease endotypes. We predict that patients with a preponderance of susceptibility variants in each group are likely...

Spatial-time-state fusion algorithm for defect detection through eddy current pulsed thermography

Science.gov (United States)

Xiao, Xiang; Gao, Bin; Woo, Wai Lok; Tian, Gui Yun; Xiao, Xiao Ting

2018-05-01

Eddy Current Pulsed Thermography (ECPT) has received extensive attention due to its high sensitive of detectability on surface and subsurface cracks. However, it remains as a difficult challenge in unsupervised detection as to identify defects without knowing any prior knowledge. This paper presents a spatial-time-state features fusion algorithm to obtain fully profile of the defects by directional scanning. The proposed method is intended to conduct features extraction by using independent component analysis (ICA) and automatic features selection embedding genetic algorithm. Finally, the optimal feature of each step is fused to obtain defects reconstruction by applying common orthogonal basis extraction (COBE) method. Experiments have been conducted to validate the study and verify the efficacy of the proposed method on blind defect detection.

Defected and Functionalized Germanene based Nanosensors under Sulfur Comprising Gas Exposure

KAUST Repository

Hussain, Tanveer

2018-03-27

Efficient sensing of sulfur containing toxic gases like H2S and SO2 is of outmost importance due to the adverse effects of these noxious gases. Absence of an efficient 2D based nanosensors capable of anchoring H2S and SO2 with feasible binding and an apparent variation in electronic properties upon the exposure of gas molecules has motivated us to explore the promise of germanene nano sheet (Ge-NS) for this purpose. In the present study, we have performed a comprehensive computational investigation by means of DFT based first principles calculations to envisage the structural, electronic and gas sensing properties of pristine, defected and metal substituted Ge-NS. Our initial screening has revealed that although interaction of SO2 on pristine Ge-NS is within the desirable range, however H2S binding is falling below the required values to guarantee an effective sensing. To improve the binding characteristics, we have considered the interactions between H2S and SO2 with defected and metal substituted Ge-NS. The systematic removals of Ge atoms from a reasonably large super cell lead to mono-vacancy, di-vacancies and tri-vacancies in Ge-NS. Similarly, different transition metals like As, Co, Cu, Fe, Ga, Ge Ni and Zn have been substituted into the monolayer to realize substituted Ge-NS. Our van der Waals corrected DFT calculations have concluded that the vacancy and substitution defects not only improve the binding characteristics but also enhance the sensing propensity of both H2S and SO2. The total and projected density of states show significant variations in electronic properties of pristine and defected Ge-NS before and after the exposure to the gases, which are essential in constituting a signal to be detected by the external circuit of the sensor. We strongly believe that out present work would not only advance the knowledge towards the application of Ge-NS based sensing, but also provide the motivation for the synthesis of an efficient nanosensors for H2S and SO

Exploring Genetic Suppression Interactions on a Global Scale

OpenAIRE

van Leeuwen, Jolanda; Pons, Carles; Mellor, Joseph C.; Yamaguchi, Takafumi N.; Friesen, Helena; Koschwanez, John; Ušaj, Mojca Mattiazzi; Pechlaner, Maria; Takar, Mehmet; Ušaj, Matej; VanderSluis, Benjamin; Andrusiak, Kerry; Bansal, Pritpal; Baryshnikova, Anastasia; Boone, Claire

2016-01-01

Genetic suppression occurs when the phenotypic defects caused by a mutation in a particular gene are rescued by a mutation in a second gene. To explore the principles of genetic suppression, we examined both literature-curated and unbiased experimental data, involving systematic genetic mapping and whole-genome sequencing, to generate a large-scale suppression network among yeast genes. Most suppression pairs identified novel relationships among functionally related genes, providing new insig...

Point defects dynamics in a stress field

International Nuclear Information System (INIS)

Smetniansky de De Grande, Nelida.

1989-01-01

The dependence of anisotropic defect diffusion on stress is studied for a hexagonal close packed (hcp) material under irradiation and uniaxially stressed. The diffusion is described as a discrete process of thermally activated jumps. It is shown that the presence of an external stress field enhances the intrinsic anisotropic diffusion, being this variation determined by the defect dipole tensors' symmetry in the equilibrium and saddle point configurations. Also, the point defect diffusion equations to sinks, like edge dislocations and spherical cavities, are solved and the sink strengths are calculated. The conclusion is that the dynamics of the interaction between defects and sinks is controlled by the changes in diffusivity induced by stress fields. (Author) [es

Feline genetics: clinical applications and genetic testing.

Science.gov (United States)

Lyons, Leslie A

2010-11-01

DNA testing for domestic cat diseases and appearance traits is a rapidly growing asset for veterinary medicine. Approximately 33 genes contain 50 mutations that cause feline health problems or alterations in the cat's appearance. A variety of commercial laboratories can now perform cat genetic diagnostics, allowing both the veterinary clinician and the private owner to obtain DNA test results. DNA is easily obtained from a cat via a buccal swab with a standard cotton bud or cytological brush, allowing DNA samples to be easily sent to any laboratory in the world. The DNA test results identify carriers of the traits, predict the incidence of traits from breeding programs, and influence medical prognoses and treatments. An overall goal of identifying these genetic mutations is the correction of the defect via gene therapies and designer drug therapies. Thus, genetic testing is an effective preventative medicine and a potential ultimate cure. However, genetic diagnostic tests may still be novel for many veterinary practitioners and their application in the clinical setting needs to have the same scrutiny as any other diagnostic procedure. This article will review the genetic tests for the domestic cat, potential sources of error for genetic testing, and the pros and cons of DNA results in veterinary medicine. Highlighted are genetic tests specific to the individual cat, which are a part of the cat's internal genome. Copyright © 2010 Elsevier Inc. All rights reserved.

Many Genes—One Disease? Genetics of Nephronophthisis (NPHP and NPHP-Associated Disorders

Directory of Open Access Journals (Sweden)

Shalabh Srivastava

2018-01-01

Full Text Available Nephronophthisis (NPHP is a renal ciliopathy and an autosomal recessive cause of cystic kidney disease, renal fibrosis, and end-stage renal failure, affecting children and young adults. Molecular genetic studies have identified more than 20 genes underlying this disorder, whose protein products are all related to cilia, centrosome, or mitotic spindle function. In around 15% of cases, there are additional features of a ciliopathy syndrome, including retinal defects, liver fibrosis, skeletal abnormalities, and brain developmental disorders. Alongside, gene identification has arisen molecular mechanistic insights into the disease pathogenesis. The genetic causes of NPHP are discussed in terms of how they help us to define treatable disease pathways including the cyclic adenosine monophosphate pathway, the mTOR pathway, Hedgehog signaling pathways, and DNA damage response pathways. While the underlying pathology of the many types of NPHP remains similar, the defined disease mechanisms are diverse, and a personalized medicine approach for therapy in NPHP patients is likely to be required.

CoaSim: A Flexible Environment for Simulating Genetic Data under Coalescent Models

DEFF Research Database (Denmark)

Mailund; Schierup, Mikkel Heide; Pedersen, Christian Nørgaard Storm

2005-01-01

get insight into these. Results We have created the CoaSim application as a flexible environment for Monte various types of genetic data under equilibrium and non-equilibrium coalescent variety of applications. Interaction with the tool is through the Guile version scripting language. Scheme scripts......Background Coalescent simulations are playing a large role in interpreting large scale intra- polymorphism surveys and for planning and evaluating association studies. Coalescent of data sets under different models can be compared to the actual data to test different evolutionary factors and thus...

Defected and Functionalized Germanene based Nanosensors under Sulfur Comprising Gas Exposure

KAUST Repository

Hussain, Tanveer; kaewmaraya, thanayut; Chakraborty, Sudip; Vovusha, Hakkim; Amornkitbamrung, Vittaya; Ahuja, Rajeev

2018-01-01

by means of DFT based first principles calculations to envisage the structural, electronic and gas sensing properties of pristine, defected and metal substituted Ge-NS. Our initial screening has revealed that although interaction of SO2 on pristine Ge

Feature selection for neural network based defect classification of ceramic components using high frequency ultrasound.

Science.gov (United States)

Kesharaju, Manasa; Nagarajah, Romesh

2015-09-01

The motivation for this research stems from a need for providing a non-destructive testing method capable of detecting and locating any defects and microstructural variations within armour ceramic components before issuing them to the soldiers who rely on them for their survival. The development of an automated ultrasonic inspection based classification system would make possible the checking of each ceramic component and immediately alert the operator about the presence of defects. Generally, in many classification problems a choice of features or dimensionality reduction is significant and simultaneously very difficult, as a substantial computational effort is required to evaluate possible feature subsets. In this research, a combination of artificial neural networks and genetic algorithms are used to optimize the feature subset used in classification of various defects in reaction-sintered silicon carbide ceramic components. Initially wavelet based feature extraction is implemented from the region of interest. An Artificial Neural Network classifier is employed to evaluate the performance of these features. Genetic Algorithm based feature selection is performed. Principal Component Analysis is a popular technique used for feature selection and is compared with the genetic algorithm based technique in terms of classification accuracy and selection of optimal number of features. The experimental results confirm that features identified by Principal Component Analysis lead to improved performance in terms of classification percentage with 96% than Genetic algorithm with 94%. Copyright © 2015 Elsevier B.V. All rights reserved.

Congenital and Genetic Disease in Domestic Animals

Science.gov (United States)

Mulvihill, John J.

1972-01-01

Reviews observations on domestic animals that have led to the identification of environmental teratogens, and have provided insight into the pathogenesis of congenital defects and genetic diseases in man." (Author/AL)

Convergent synaptic and circuit substrates underlying autism genetic risks.

Science.gov (United States)

McGee, Aaron; Li, Guohui; Lu, Zhongming; Qiu, Shenfeng

2014-02-01

There has been a surge of diagnosis of autism spectrum disorders (ASD) over the past decade. While large, high powered genome screening studies of children with ASD have identified numerous genetic risk factors, research efforts to understanding how each of these risk factors contributes to the development autism has met with limited success. Revealing the mechanisms by which these genetic risk factors affect brain development and predispose a child to autism requires mechanistic understanding of the neurobiological changes underlying this devastating group of developmental disorders at multifaceted molecular, cellular and system levels. It has been increasingly clear that the normal trajectory of neurodevelopment is compromised in autism, in multiple domains as much as aberrant neuronal production, growth, functional maturation, patterned connectivity, and balanced excitation and inhibition of brain networks. Many autism risk factors identified in humans have been now reconstituted in experimental mouse models to allow mechanistic interrogation of the biological role of the risk gene. Studies utilizing these mouse models have revealed that underlying the enormous heterogeneity of perturbed cellular events, mechanisms directing synaptic and circuit assembly may provide a unifying explanation for the pathophysiological changes and behavioral endophenotypes seen in autism, although synaptic perturbations are far from being the only alterations relevant for ASD. In this review, we discuss synaptic and circuit abnormalities obtained from several prevalent mouse models, particularly those reflecting syndromic forms of ASD that are caused by single gene perturbations. These compiled results reveal that ASD risk genes contribute to proper signaling of the developing gene networks that maintain synaptic and circuit homeostasis, which is fundamental to normal brain development.

The fractal character of radiation defects aggregation in crystals

International Nuclear Information System (INIS)

Akylbekov, A.; Akimbekov, E.; Baktybekov, K.; Vasil'eva, I.

2002-01-01

In processes of self-organization, which characterize open systems, the source of ordering is a non-equilibrium. One of the samples of ordering system is radiation-stimulated aggregation of defects in solids. In real work the analysis of criterions of ordering defects structures in solid, which is continuously irradiate at low temperature is presented. The method of cellular automata used in simulation of irradiation. It allowed us to imitate processes of defects formation and recombination. The simulation realized on the surfaces up to 1000x1000 units with initial concentration of defects C n (the power of dose) 0.1-1 %. The number of iterations N (duration of irradiation) mounted to 10 6 cycles. The single centers, which are the sources of formation aggregates, survive in the result of probabilistic nature of formation and recombination genetic pairs of defects and with strictly fixed radius of recombination (the minimum inter anionic distance). For determination the character of same type defects distribution the potential of their interaction depending of defects type and reciprocal distance is calculated. For more detailed study of processes, proceeding in cells with certain sizes of aggregates, the time dependence of potential interaction is constructed. It is shown, that on primary stage the potential is negative, then it increase and approach the saturation in positive area. The minimum of interaction potential corresponds to state of physical chaos in system. Its increasing occurs with formation of same type defects aggregates. Further transition to saturation and 'undulating' character of curves explains by formation and destruction aggregates. The data indicated that - these processes occur simultaneously in cells with different sizes. It allows us to assume that the radiation defects aggregation have a fractal nature

Considering genetic characteristics in German Holstein breeding programs.

Science.gov (United States)

Segelke, D; Täubert, H; Reinhardt, F; Thaller, G

2016-01-01

Recently, several research groups have demonstrated that several haplotypes may cause embryonic loss in the homozygous state. Up to now, carriers of genetic disorders were often excluded from mating, resulting in a decrease of genetic gain and a reduced number of sires available for the breeding program. Ongoing research is very likely to identify additional genetic defects causing embryonic loss and calf mortality by genotyping a large proportion of the female cattle population and sequencing key ancestors. Hence, a clear demand is present to develop a method combining selection against recessive defects (e.g., Holstein haplotypes HH1-HH5) with selection for economically beneficial traits (e.g., polled) for mating decisions. Our proposed method is a genetic index that accounts for the allele frequencies in the population and the economic value of the genetic characteristic without excluding carriers from breeding schemes. Fertility phenotypes from routine genetic evaluations were used to determine the economic value per embryo lost. Previous research has shown that embryo loss caused by HH1 and HH2 occurs later than the loss for HH3, HH4, and HH5. Therefore, an economic value of € 97 was used against HH1 and HH2 and € 70 against HH3, HH4, and HH5. For polled, € 7 per polled calf was considered. Minor allele frequencies of the defects ranged between 0.8 and 3.3%. The polled allele has a frequency of 4.1% in the German Holstein population. A genomic breeding program was simulated to study the effect of changing the selection criteria from assortative mating based on breeding values to selecting the females using the genetic index. Selection for a genetic index on the female path is a useful method to control the allele frequencies by reducing undesirable alleles and simultaneously increasing economical beneficial characteristics maintaining most of the genetic gain in production and functional traits. Additionally, we applied the genetic index to real data and

[Diagnostics of the genetic causes of autism spectrum disorders - a clinical geneticist's view].

Science.gov (United States)

Szczaluba, Krzysztof

2014-01-01

Explanation of the genetic basis of autism spectrum disorders has, for many decades, been a part of interest of researchers and clinicians. In recent years, thanks to modern molecular and cytogenetic techniques, a significant progress has been achieved in the diagnosis of genetic causes of autism. This applies particularly, but not exclusively, to those cases of autism that are accompanied by other clinical signs (i. e. complex phenotypes). The important clinical markers belong to different categories, and include congenital defects/anomalies, dysmorphism and macro-/microcephaly, to name the few. Thus, the choice of the diagnostic strategy depends on the clinical and pedigree information and, under Polish circumstances, the availability of specific diagnostic techniques and the amount of reimbursement under the National Health Service. Overall, the identification of the genetic causes of autism spectrum disorders is possible in about 10-30% of patients. In this paper the practical aspects of the use of different diagnostic techniques are briefly described. Some clinical examples and current recommendations for the diagnosis of patients with autism spectrum disorders are also presented. The point of view of a specialist in clinical genetics, increasingly involved, as part of the multidisciplinary care team, in the diagnostics of an autistic child has been demonstrated.

Over-expression of DSCAM and COL6A2 cooperatively generates congenital heart defects.

Directory of Open Access Journals (Sweden)

Tamar R Grossman

2011-11-01

Full Text Available A significant current challenge in human genetics is the identification of interacting genetic loci mediating complex polygenic disorders. One of the best characterized polygenic diseases is Down syndrome (DS, which results from an extra copy of part or all of chromosome 21. A short interval near the distal tip of chromosome 21 contributes to congenital heart defects (CHD, and a variety of indirect genetic evidence suggests that multiple candidate genes in this region may contribute to this phenotype. We devised a tiered genetic approach to identify interacting CHD candidate genes. We first used the well vetted Drosophila heart as an assay to identify interacting CHD candidate genes by expressing them alone and in all possible pairwise combinations and testing for effects on rhythmicity or heart failure following stress. This comprehensive analysis identified DSCAM and COL6A2 as the most strongly interacting pair of genes. We then over-expressed these two genes alone or in combination in the mouse heart. While over-expression of either gene alone did not affect viability and had little or no effect on heart physiology or morphology, co-expression of the two genes resulted in ≈50% mortality and severe physiological and morphological defects, including atrial septal defects and cardiac hypertrophy. Cooperative interactions between DSCAM and COL6A2 were also observed in the H9C2 cardiac cell line and transcriptional analysis of this interaction points to genes involved in adhesion and cardiac hypertrophy. Our success in defining a cooperative interaction between DSCAM and COL6A2 suggests that the multi-tiered genetic approach we have taken involving human mapping data, comprehensive combinatorial screening in Drosophila, and validation in vivo in mice and in mammalian cells lines should be applicable to identifying specific loci mediating a broad variety of other polygenic disorders.

Ab initio study of native defects in SnO under strain

KAUST Repository

Bianchi Granato, Danilo; Albar, Arwa; Schwingenschlö gl, Udo

2014-01-01

Tin monoxide (SnO) has promising properties to be applied as a p-type semiconductor in transparent electronics. To this end, it is necessary to understand the behaviour of defects in order to control them. We use density functional theory to study

Circulating anti-Mullerian hormone levels in adult men are under a strong genetic influence.

Science.gov (United States)

Pietiläinen, Kirsi H; Kaprio, Jaakko; Vaaralahti, Kirsi; Rissanen, Aila; Raivio, Taneli

2012-01-01

The determinants of serum anti-Müllerian hormone (AMH) levels in adult men remain unclear. The objective of the study was to investigate the genetic and environmental components in determining postpubertal AMH levels in healthy men. Serum AMH levels, body mass index (BMI), and fat mass (dual energy x-ray absorptiometry) were measured in 64 healthy male (23 monozygotic and 41 dizygotic) twin pairs. Postpubertal AMH levels were highly genetically determined (broad sense heritability 0.92, 95% confidence interval 0.83-0.96). AMH correlated negatively with BMI (r = -0.26, P = 0.030) and fat mass (r = -0.23, P = 0.048). As AMH, BMI had a high heritability (0.68, 95% confidence interval 0.39-0.83), but no genetic correlation was observed between them. AMH levels in men after puberty are under a strong genetic influence. Twin modeling suggests that AMH and BMI are influenced by different sets of genes.

Thyroid Medication Use and Birth Defects in the National Birth Defects Prevention Study.

Science.gov (United States)

Howley, Meredith M; Fisher, Sarah C; Van Zutphen, Alissa R; Waller, Dorothy K; Carmichael, Suzan L; Browne, Marilyn L

2017-11-01

Thyroid disorders are common among reproductive-aged women, with hypothyroidism affecting 2 to 3% of pregnancies, and hyperthyroidism affecting an additional 0.1 to 1%. We examined associations between thyroid medications and individual birth defects using data from the National Birth Defects Prevention Study (NBDPS). The NBDPS is a multisite, population-based, case-control study that included pregnancies with estimated delivery dates from 1997 to 2011. We analyzed self-reported thyroid medication use from mothers of 31,409 birth defect cases and 11,536 unaffected controls. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression for birth defects with five or more exposed cases, controlling for maternal age, race/ethnicity, and study center. Crude ORs and exact 95% CIs were estimated for defects with 3 to 4 exposed cases. Thyroid hormone was used by 738 (2.3%) case and 237 (2.1%) control mothers, and was associated with anencephaly (OR = 1.68; 95% CI, 1.03-2.73), holoprosencephaly (OR = 2.48; 95% CI, 1.13-5.44), hydrocephaly (1.77; 95% CI, 1.07-2.95) and small intestinal atresia (OR = 1.81; 95% CI, 1.04-3.15). Anti-thyroid medication was used by 34 (0.1%) case and 10 (<0.1%) control mothers, and was associated with aortic valve stenosis (OR = 6.91; 95% CI, 1.21-27.0). While new associations were identified, our findings are relatively consistent with previous NBDPS analyses. Our findings suggest thyroid medication use is not associated with most birth defects studied in the NBDPS, but may be associated with some specific birth defects. These results should not be interpreted to suggest that medications used to treat thyroid disease are teratogens, as the observed associations may reflect effects of the underlying thyroid disease. Birth Defects Research 109:1471-1481, 2017.© 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Human syndromes with congenital patellar anomalies and the underlying gene defects.

NARCIS (Netherlands)

Bongers, E.M.H.F.; Kampen, A. van; Bokhoven, J.H.L.M. van; Knoers, N.V.A.M.

2005-01-01

Genetic disorders characterized by congenital patellar aplasia or hypoplasia belong to a clinically diverse and genetically heterogeneous group of lower limb malformations. Patella development involves different molecular and cellular mechanisms regulating dorso-ventral patterning, cartilage and

Features of transformation of impurity-defect complexes in СdTe:Сl under the influence of microwave radiation

Directory of Open Access Journals (Sweden)

Budzulyak S. I.

2014-08-01

Full Text Available High-resistance cadmium telluride single crystals are promising material for production of ionizing radiation detectors. To increase crystal resistance, they are doped with chlorine. The detector quality depends on uniformity of chlorine impurity distribution over crystal. It is known that low-dose microwave irradiation can homogenize impurity distribution in a specimen. In the present work, we made an attempt to improve the detector material quality by using such post-technological treatment, as well as to study state variation for impurity-defect complexes. To this end, the effect of microwave irradiation on transformation of impurity-defect complexes in CdTe:Cl single crystals was investigated using low-temperature photoluminescence. It is shown that activation of ClTe donor centers by microwave irradiation for 10 s and presence of VCd acceptor centers in the specimens under investigation effectively facilitate formation of (VNd–ClTe defect centers at which excitons are bound. Detailed investigations of the band form for donor-acceptor pairs (DAPs in CdTe:Cl single crystals made it possible to determine the Huang—Rhys factor (that characterizes electron-phonon interaction in CdTe:Cl DAPs as a function of microwave treatment duration. It is shown for single crystals with NCl = 5·1017 cm–3 and 5·1019 cm–3 that the Huang—Rhys factor grows with microwave irradiation dose. This is related to both homogenization of donor and acceptor centers distribution and increase of donor—acceptor spacing. It is shown that microwave irradiation of CdTe:Cl single crystals results in concentration reduction for separate cadmium vacancies VCd because of formation of (VNd—ClTe defect centers at which excitons are bound.

Proteomic approach to characterize biochemistry of meat quality defects.

Science.gov (United States)

Schilling, M W; Suman, S P; Zhang, X; Nair, M N; Desai, M A; Cai, K; Ciaramella, M A; Allen, P J

2017-10-01

Proteomics can be used to characterize quality defects including pale, soft, and exudative (PSE) meat (pork and poultry), woody broiler breast meat, reddish catfish fillets, meat toughness, and beef myoglobin oxidation. PSE broiler meat was characterized by 15 proteins that differed in abundance in comparison to normal broiler breast meat, and eight proteins were differentially expressed in woody breast meat in comparison to normal breast meat. Hemoglobin was the only protein that was differentially expressed between red and normal catfish fillets. However, inducing low oxygen and/or heat stress conditions to catfish fillets did not lead to the production of red fillets. Proteomic data provided information pertaining to the protein differences that exist in meat quality defects. However, these data need to be evaluated in conjunction with information pertaining to genetics, nutrition, environment of the live animal, muscle to meat conversion, meat quality analyses and sensory attributes to understand causality, protein biomarkers, and ultimately how to prevent quality defects. Copyright © 2017 Elsevier Ltd. All rights reserved.

Using Drosophila to discover mechanisms underlying type 2 diabetes

Directory of Open Access Journals (Sweden)

Ronald W. Alfa

2016-04-01

Full Text Available Mechanisms of glucose homeostasis are remarkably well conserved between the fruit fly Drosophila melanogaster and mammals. From the initial characterization of insulin signaling in the fly came the identification of downstream metabolic pathways for nutrient storage and utilization. Defects in these pathways lead to phenotypes that are analogous to diabetic states in mammals. These discoveries have stimulated interest in leveraging the fly to better understand the genetics of type 2 diabetes mellitus in humans. Type 2 diabetes results from insulin insufficiency in the context of ongoing insulin resistance. Although genetic susceptibility is thought to govern the propensity of individuals to develop type 2 diabetes mellitus under appropriate environmental conditions, many of the human genes associated with the disease in genome-wide association studies have not been functionally studied. Recent advances in the phenotyping of metabolic defects have positioned Drosophila as an excellent model for the functional characterization of large numbers of genes associated with type 2 diabetes mellitus. Here, we examine results from studies modeling metabolic disease in the fruit fly and compare findings to proposed mechanisms for diabetic phenotypes in mammals. We provide a systematic framework for assessing the contribution of gene candidates to insulin-secretion or insulin-resistance pathways relevant to diabetes pathogenesis.

Electron scattering in graphene by defects in underlying h-BN layer: First-principles transport calculations

Science.gov (United States)

Kaneko, Tomoaki; Ohno, Takahisa

2018-03-01

We investigate the electronic structure and the transport properties of graphene adsorbed onto h-BN with carbon impurities or atomic vacancies using density functional theory and the non-equilibrium Green's function method. We find that the transport properties are degraded due to carrier doping and scattering off of localized defect states in h-BN. When graphene is doped by introducing defects in h-BN, the transmission spectra become asymmetric owing to the reduction of the electronic density of states, which contributes significantly to the degradation of graphene transport properties as compared with the effect of defect levels.

Collision avoidance in persons with homonymous visual field defects under virtual reality conditions.

Science.gov (United States)

Papageorgiou, Eleni; Hardiess, Gregor; Ackermann, Hermann; Wiethoelter, Horst; Dietz, Klaus; Mallot, Hanspeter A; Schiefer, Ulrich

2012-01-01

The aim of the present study was to examine the effect of homonymous visual field defects (HVFDs) on collision avoidance of dynamic obstacles at an intersection under virtual reality (VR) conditions. Overall performance was quantitatively assessed as the number of collisions at a virtual intersection at two difficulty levels. HVFDs were assessed by binocular semi-automated kinetic perimetry within the 90° visual field, stimulus III4e and the area of sparing within the affected hemifield (A-SPAR in deg(2)) was calculated. The effect of A-SPAR, age, gender, side of brain lesion, time since brain lesion and presence of macular sparing on the number of collisions, as well as performance over time were investigated. Thirty patients (10 female, 20 male, age range: 19-71 years) with HVFDs due to unilateral vascular brain lesions and 30 group-age-matched subjects with normal visual fields were examined. The mean number of collisions was higher for patients and in the more difficult level they experienced more collisions with vehicles approaching from the blind side than the seeing side. Lower A-SPAR and increasing age were associated with decreasing performance. However, in agreement with previous studies, wide variability in performance among patients with identical visual field defects was observed and performance of some patients was similar to that of normal subjects. Both patients and healthy subjects displayed equal improvement of performance over time in the more difficult level. In conclusion, our results suggest that visual-field related parameters per se are inadequate in predicting successful collision avoidance. Individualized approaches which also consider compensatory strategies by means of eye and head movements should be introduced. Copyright © 2011 Elsevier Ltd. All rights reserved.

Deciphering molecular circuits from genetic variation underlying transcriptional responsiveness to stimuli.

Science.gov (United States)

Gat-Viks, Irit; Chevrier, Nicolas; Wilentzik, Roni; Eisenhaure, Thomas; Raychowdhury, Raktima; Steuerman, Yael; Shalek, Alex K; Hacohen, Nir; Amit, Ido; Regev, Aviv

2013-04-01

Individual genetic variation affects gene responsiveness to stimuli, often by influencing complex molecular circuits. Here we combine genomic and intermediate-scale transcriptional profiling with computational methods to identify variants that affect the responsiveness of genes to stimuli (responsiveness quantitative trait loci or reQTLs) and to position these variants in molecular circuit diagrams. We apply this approach to study variation in transcriptional responsiveness to pathogen components in dendritic cells from recombinant inbred mouse strains. We identify reQTLs that correlate with particular stimuli and position them in known pathways. For example, in response to a virus-like stimulus, a trans-acting variant responds as an activator of the antiviral response; using RNA interference, we identify Rgs16 as the likely causal gene. Our approach charts an experimental and analytic path to decipher the mechanisms underlying genetic variation in circuits that control responses to stimuli.

Neuroradiologic findings in children with mitochondrial disorder: correlation with mitochondrial respiratory chain defects

International Nuclear Information System (INIS)

Kim, Jinna; Lee, Seung-Koo; Kim, Dong Ik; Kim, Eung Yeop; Lee, Young-Mock; Lee, Joon Soo; Kim, Heung Dong

2008-01-01

Mitochondrial disorders are a heterogeneous group of disorders affecting energy metabolism that can present at any age with a wide variety of clinical symptoms. We investigated brain magnetic resonance (MR) findings in 40 children with defects of the mitochondrial respiratory chain (MRC) complex and correlated them with the type of MRC defects. Enrolled were 40 children with MRC defects in biochemical enzyme assay of the muscle specimen. Twenty-one children were found to have classical syndromes of mitochondrial disorders and 19 children presented nonspecific mitochondrial encephalomyopathies. Their brain MR imaging findings were retrospectively reviewed and correlated with the biochemical defect in the MRC complex. Children with MRC defects showed various neuroradiologic features on brain MR imaging that resulted from a complex genetic background and a heterogeneous phenotype. Rapid progression of atrophy involving all structures of the brain with variable involvement of deep gray and white matter are the most frequent MR findings in children with MRC defects in both classical syndromes of mitochondrial disorder and nonspecific mitochondrial encephalomyopathies. The type of biochemical defect in the MRC complex enzyme did not correlate with brain MR findings in child patients. (orig.)

Neuroradiologic findings in children with mitochondrial disorder: correlation with mitochondrial respiratory chain defects

Energy Technology Data Exchange (ETDEWEB)

Kim, Jinna; Lee, Seung-Koo; Kim, Dong Ik [Yonsei University College of Medicine, Department of Radiology, Research Institute of Radiological Science, Seoul (Korea); Kim, Eung Yeop [Yonsei University College of Medicine, Department of Radiology, Research Institute of Radiological Science, Brain Korea 21 Project for Medical Science, Seoul (Korea); Lee, Young-Mock; Lee, Joon Soo [Yonsei University College of Medicine, Department of Pediatrics, Pediatric Epilepsy Clinics, Severance Children' s Hospital, Brain Research Institute, Seoul (Korea); Kim, Heung Dong [Yonsei University College of Medicine, Department of Pediatrics, Pediatric Epilepsy Clinics, Severance Children' s Hospital, Brain Research Institute, Seoul (Korea); Yonsei University College of Medicine, Department of Pediatrics, Seoul (Korea)

2008-08-15

Mitochondrial disorders are a heterogeneous group of disorders affecting energy metabolism that can present at any age with a wide variety of clinical symptoms. We investigated brain magnetic resonance (MR) findings in 40 children with defects of the mitochondrial respiratory chain (MRC) complex and correlated them with the type of MRC defects. Enrolled were 40 children with MRC defects in biochemical enzyme assay of the muscle specimen. Twenty-one children were found to have classical syndromes of mitochondrial disorders and 19 children presented nonspecific mitochondrial encephalomyopathies. Their brain MR imaging findings were retrospectively reviewed and correlated with the biochemical defect in the MRC complex. Children with MRC defects showed various neuroradiologic features on brain MR imaging that resulted from a complex genetic background and a heterogeneous phenotype. Rapid progression of atrophy involving all structures of the brain with variable involvement of deep gray and white matter are the most frequent MR findings in children with MRC defects in both classical syndromes of mitochondrial disorder and nonspecific mitochondrial encephalomyopathies. The type of biochemical defect in the MRC complex enzyme did not correlate with brain MR findings in child patients. (orig.)

Genetic Variability Under the Seedbank Coalescent.

Science.gov (United States)

Blath, Jochen; González Casanova, Adrián; Eldon, Bjarki; Kurt, Noemi; Wilke-Berenguer, Maite

2015-07-01

We analyze patterns of genetic variability of populations in the presence of a large seedbank with the help of a new coalescent structure called the seedbank coalescent. This ancestral process appears naturally as a scaling limit of the genealogy of large populations that sustain seedbanks, if the seedbank size and individual dormancy times are of the same order as those of the active population. Mutations appear as Poisson processes on the active lineages and potentially at reduced rate also on the dormant lineages. The presence of "dormant" lineages leads to qualitatively altered times to the most recent common ancestor and nonclassical patterns of genetic diversity. To illustrate this we provide a Wright-Fisher model with a seedbank component and mutation, motivated from recent models of microbial dormancy, whose genealogy can be described by the seedbank coalescent. Based on our coalescent model, we derive recursions for the expectation and variance of the time to most recent common ancestor, number of segregating sites, pairwise differences, and singletons. Estimates (obtained by simulations) of the distributions of commonly employed distance statistics, in the presence and absence of a seedbank, are compared. The effect of a seedbank on the expected site-frequency spectrum is also investigated using simulations. Our results indicate that the presence of a large seedbank considerably alters the distribution of some distance statistics, as well as the site-frequency spectrum. Thus, one should be able to detect from genetic data the presence of a large seedbank in natural populations. Copyright © 2015 by the Genetics Society of America.

Consequences of the genetic threshold model for observing partial migration under climate change scenarios.

Science.gov (United States)

Cobben, Marleen M P; van Noordwijk, Arie J

2017-10-01

Migration is a widespread phenomenon across the animal kingdom as a response to seasonality in environmental conditions. Partially migratory populations are populations that consist of both migratory and residential individuals. Such populations are very common, yet their stability has long been debated. The inheritance of migratory activity is currently best described by the threshold model of quantitative genetics. The inclusion of such a genetic threshold model for migratory behavior leads to a stable zone in time and space of partially migratory populations under a wide range of demographic parameter values, when assuming stable environmental conditions and unlimited genetic diversity. Migratory species are expected to be particularly sensitive to global warming, as arrival at the breeding grounds might be increasingly mistimed as a result of the uncoupling of long-used cues and actual environmental conditions, with decreasing reproduction as a consequence. Here, we investigate the consequences for migratory behavior and the stability of partially migratory populations under five climate change scenarios and the assumption of a genetic threshold value for migratory behavior in an individual-based model. The results show a spatially and temporally stable zone of partially migratory populations after different lengths of time in all scenarios. In the scenarios in which the species expands its range from a particular set of starting populations, the genetic diversity and location at initialization determine the species' colonization speed across the zone of partial migration and therefore across the entire landscape. Abruptly changing environmental conditions after model initialization never caused a qualitative change in phenotype distributions, or complete extinction. This suggests that climate change-induced shifts in species' ranges as well as changes in survival probabilities and reproductive success can be met with flexibility in migratory behavior at the

Imaging active topological defects in carbon nanotubes

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Suenaga, Kazu; Wakabayashi, Hideaki; Koshino, Masanori; Sato, Yuta; Urita, Koki; Iijima, Sumio

2007-06-01

A single-walled carbon nanotube (SWNT) is a wrapped single graphene layer, and its plastic deformation should require active topological defects-non-hexagonal carbon rings that can migrate along the nanotube wall. Although in situ transmission electron microscopy (TEM) has been used to examine the deformation of SWNTs, these studies deal only with diameter changes and no atomistic mechanism has been elucidated experimentally. Theory predicts that some topological defects can form through the Stone-Wales transformation in SWNTs under tension at 2,000 K, and could act as a dislocation core. We demonstrate here, by means of high-resolution (HR)-TEM with atomic sensitivity, the first direct imaging of pentagon-heptagon pair defects found in an SWNT that was heated at 2,273 K. Moreover, our in situ HR-TEM observation reveals an accumulation of topological defects near the kink of a deformed nanotube. This result suggests that dislocation motions or active topological defects are indeed responsible for the plastic deformation of SWNTs.

Defect sizing using automated ultrasonic inspection techniques at RNL

International Nuclear Information System (INIS)

Rogerson, A.; Highmore, P.J.; Poulter, L.N.J.

1983-10-01

RNL has developed and applied automated wide-beam pulse-echo and time-of-flight techniques with synthetic aperture processing for sizing defects in clad thick-section weldments and nozzle corner regions. These techniques were amongst those used in the four test plate inspections making up the UKAEA Defect Detection Trials. In this report a critical appraisal is given of the sizing procedures adopted by RNL in these inspections. Several factors influencing sizing accuracy are discussed and results from particular defects highlighted. The time-of-flight technique with colour graphics data display is shown to be highly effective in imaging near-vertical buried defects and underclad defects of height greater than 5 mm. Early characterisation of any identified defect from its ultrasonic response under pulse-echo inspection is seen as a desirable aid to the selection of an appropriate advanced sizing technique for buried defects. (author)

Congenital Heart Defects and Receipt of Special Education Services.

Science.gov (United States)

Riehle-Colarusso, Tiffany; Autry, Andrew; Razzaghi, Hilda; Boyle, Coleen A; Mahle, William T; Van Naarden Braun, Kim; Correa, Adolfo

2015-09-01

We investigated the prevalence of receipt of special education services among children with congenital heart defects (CHDs) compared with children without birth defects. Children born from 1982 to 2004 in metropolitan Atlanta with CHDs (n = 3744) were identified from a population-based birth defect surveillance program; children without birth defects (n = 860 715) were identified from birth certificates. Cohorts were linked to special education files for the 1992-2012 school years to identify special education services. Children with noncardiac defects or genetic syndromes were excluded; children with CHDs were classified by presence or absence of critical CHDs (ie, CHDs requiring intervention by age one year). We evaluated the prevalence of receipt of special education services and prevalence rate ratios using children without birth defects as a reference. Compared with children without birth defects, children with CHDs were 50% more likely to receive special education services overall (adjusted prevalence rate ratio [aPRR] = 1.5; 95% confidence interval [CI]: 1.4-1.7). Specifically, they had higher prevalence of several special education categories including: intellectual disability (aPRR = 3.8; 95% CI: 2.8-5.1), sensory impairment (aPRR = 3.0; 95% CI: 1.8-5.0), other health impairment (aPRR = 2.8; 95% CI: 2.2-3.5), significant developmental delay (aPRR = 1.9; 95% CI: 1.3-2.8), and specific learning disability (aPRR = 1.4; 95% CI: 1.1-1.7). For most special education services, the excess prevalence did not vary by presence of critical CHDs. Children with CHDs received special education services more often than children without birth defects. These findings highlight the need for special education services and the importance of developmental screening for all children with CHDs. Copyright © 2015 by the American Academy of Pediatrics.

Knowledge of Genetics and Attitudes toward Genetic Testing among College Students in Saudi Arabia.

Science.gov (United States)

Olwi, Duaa; Merdad, Leena; Ramadan, Eman

2016-01-01

Genetic testing has been gradually permeating the practice of medicine. Health-care providers may be confronted with new genetic approaches that require genetically informed decisions which will be influenced by patients' knowledge of genetics and their attitudes toward genetic testing. This study assesses the knowledge of genetics and attitudes toward genetic testing among college students. A cross-sectional study was conducted using a multistage stratified sample of 920 senior college students enrolled at King Abdulaziz University, Saudi Arabia. Information regarding knowledge of genetics, attitudes toward genetic testing, and sociodemographic data were collected using a self-administered questionnaire. In general, students had a good knowledge of genetics but lacked some fundamentals of genetics. The majority of students showed positive attitudes toward genetic testing, but some students showed negative attitudes toward certain aspects of genetic testing such as resorting to abortion in the case of an untreatable major genetic defect in an unborn fetus. The main significant predictors of knowledge were faculty, gender, academic year, and some prior awareness of 'genetic testing'. The main significant predictors of attitudes were gender, academic year, grade point average, and some prior awareness of 'genetic testing'. The knowledge of genetics among college students was higher than has been reported in other studies, and the attitudes toward genetic testing were fairly positive. Genetics educational programs that target youths may improve knowledge of genetics and create a public perception that further supports genetic testing. © 2016 S. Karger AG, Basel.

Genetics Home Reference: Griscelli syndrome

Science.gov (United States)

... Tezcan I, Ersoy F, Houdusse A, Fischer A, de Saint Basile G. Griscelli syndrome restricted to hypopigmentation results from a melanophilin defect ( ... N, Bianchi D, Fischer A, Le Deist F, de Saint Basile G. Mutations in RAB27A ... syndrome associated with haemophagocytic syndrome. Nat Genet. 2000 Jun; ...

Numerical modeling of mechanical behavior of multilayered composite plates with defects under static loading

Science.gov (United States)

Korepanov, V. V.; Serovaev, G. S.

2017-06-01

Evaluation of the mechanical state of a structure or its components in the process of operation based on detection of internal damages (damage detection) becomes especially important in such rapidly developing spheres of production as machine building, aerospace industry, etc. One of the most important features of these industries is the application of new types of materials among which polymer based composite materials occupy a significant position. Hence, they must have sufficient operational rigidity and strength. However, defects of various kinds may arise during the manufacture. Delamination is the most common defect in structures made from composite materials and represents a phenomenon that involves the complex fracture of layers and interlayer compounds. Among the reasons of delamination occurrence are: disposition of anti-adhesive lubricants, films; insufficient content of binder, high content of volatile elements; violation of the molding regime; poor quality of anti-adhesive coating on the surface of the tooling. One of the effective methods for analyzing the influence of defects is numerical simulation. With the help of numerical methods, it is possible to track the evolution of various parameters when the defect size and quantity change. In the paper, a multilayered plate of an equally resistant carbon fiber reinforced plastic was considered, with a thickness of each layer equal to 0.2 mm. Various static loading cases are studied: uniaxial tension, three and four-point bending. For each type of loading, a numerical calculation of the stress-strain state was performed for healthy and delaminated plates, with different number and size of the defects. Contact interaction between adjacent surfaces in the zone of delamination was taken into account.

Correlation between electron-irradiation defects and applied stress in graphene: A molecular dynamics study

Energy Technology Data Exchange (ETDEWEB)

Kida, Shogo; Yamamoto, Masaya; Kawata, Hiroaki; Hirai, Yoshihiko; Yasuda, Masaaki, E-mail: yasuda@pe.osakafu-u.ac.jp [Department of Physics and Electronics, Osaka Prefecture University, Sakai, Osaka 599-8531 (Japan); Tada, Kazuhiro [Department of Electrical and Control Systems Engineering, National Institute of Technology, Toyama College, Toyama 939-8630 (Japan)

2015-09-15

Molecular dynamics (MD) simulations are performed to study the correlation between electron irradiation defects and applied stress in graphene. The electron irradiation effect is introduced by the binary collision model in the MD simulation. By applying a tensile stress to graphene, the number of adatom-vacancy (AV) and Stone–Wales (SW) defects increase under electron irradiation, while the number of single-vacancy defects is not noticeably affected by the applied stress. Both the activation and formation energies of an AV defect and the activation energy of an SW defect decrease when a tensile stress is applied to graphene. Applying tensile stress also relaxes the compression stress associated with SW defect formation. These effects induced by the applied stress cause the increase in AV and SW defect formation under electron irradiation.

Dislocation defect interaction in irradiated Cu

International Nuclear Information System (INIS)

Schaeublin, R.; Yao, Z.; Spaetig, P.; Victoria, M.

2005-01-01

Pure Cu single crystals irradiated at room temperature to low doses with 590 MeV protons have been deformed in situ in a transmission electron microscope in order to identify the basic mechanisms at the origin of hardening. Cu irradiated to 10 -4 dpa shows at room temperature a yield shear stress of 13.7 MPa to be compared to the 8.8 MPa of the unirradiated Cu. Irradiation induced damage consists at 90% of 2 nm stacking fault tetrahedra, the remaining being dislocation loops and unidentified defects. In-situ deformation reveals that dislocation-defect interaction can take several forms. Usually, dislocations pinned by defects bow out under the applied stress and escape without leaving any visible defect. From the escape angles obtained at 183 K, an average critical stress of 100 MPa is deduced. In some cases, the pinning of dislocations leads to debris that are about 20 nm long, which formation could be recorded during the in situ experiment

[Folic acid: Primary prevention of neural tube defects. Literature Review].

Science.gov (United States)

Llamas Centeno, M J; Miguélez Lago, C

2016-03-01

Neural tube defects (NTD) are the most common congenital malformations of the nervous system, they have a multifactorial etiology, are caused by exposure to chemical, physical or biological toxic agents, factors deficiency, diabetes, obesity, hyperthermia, genetic alterations and unknown causes. Some of these factors are associated with malnutrition by interfering with the folic acid metabolic pathway, the vitamin responsible for neural tube closure. Its deficit produce anomalies that can cause abortions, stillbirths or newborn serious injuries that cause disability, impaired quality of life and require expensive treatments to try to alleviate in some way the alterations produced in the embryo. Folic acid deficiency is considered the ultimate cause of the production of neural tube defects, it is clear the reduction in the incidence of Espina Bifida after administration of folic acid before conception, this leads us to want to further study the action of folic acid and its application in the primary prevention of neural tube defects. More than 40 countries have made the fortification of flour with folate, achieving encouraging data of decrease in the prevalence of neural tube defects. This paper attempts to make a literature review, which clarify the current situation and future of the prevention of neural tube defects.

A case report of truncus arteriosus communis and genetic counseling

Directory of Open Access Journals (Sweden)

Gholamreza Nourzad

2013-06-01

Full Text Available BACKGROUND: Truncus arteriosus communis (TAC is a rare heart disorder with the prevalence of approximately 1%, mostly in male newborns. In this disease, aorta and pulmonary artery have not been separated during fetus development and both originate jointly from left ventricle. In addition, various disorders are reported like ventricular septal defect (VSD, mitral and tricuspid valves defects, aortic septal defect (ASD, reduction of lung and lung vessels’ resistance, pulmonary hypertension, increase in heart rate, high perspiration, bad digestion, and tetralogy of Fallot. CASR REPORT: Parents of deceased patient were referred for genetic counseling after the death of third girl due to severe cardiac disorder. Cardiologist declared the disease in deceased girl as TAC based on findings along with VSD, ASD and hypoplastic aortic arch which resulted to death in the first day of birth. CONCLUSION: There was no chromosomal disorder in chromosome analysis of patient’ skin. Parents were interested to have another child, so they were referred to university's Genetic Counseling Center to become aware of their next child’s condition. This disorder is genetically heterogeneous and multifactorial and because all external factors are not recognized, the accurate estimation of risk is not possible and the probability of risk for the next child is about 10% to 20%.   Keywords: Heart Disorder, Truncus Arteriosus Communis, Genetic Counseling 

Population genetics inference for longitudinally-sampled mutants under strong selection.

Science.gov (United States)

Lacerda, Miguel; Seoighe, Cathal

2014-11-01

Longitudinal allele frequency data are becoming increasingly prevalent. Such samples permit statistical inference of the population genetics parameters that influence the fate of mutant variants. To infer these parameters by maximum likelihood, the mutant frequency is often assumed to evolve according to the Wright-Fisher model. For computational reasons, this discrete model is commonly approximated by a diffusion process that requires the assumption that the forces of natural selection and mutation are weak. This assumption is not always appropriate. For example, mutations that impart drug resistance in pathogens may evolve under strong selective pressure. Here, we present an alternative approximation to the mutant-frequency distribution that does not make any assumptions about the magnitude of selection or mutation and is much more computationally efficient than the standard diffusion approximation. Simulation studies are used to compare the performance of our method to that of the Wright-Fisher and Gaussian diffusion approximations. For large populations, our method is found to provide a much better approximation to the mutant-frequency distribution when selection is strong, while all three methods perform comparably when selection is weak. Importantly, maximum-likelihood estimates of the selection coefficient are severely attenuated when selection is strong under the two diffusion models, but not when our method is used. This is further demonstrated with an application to mutant-frequency data from an experimental study of bacteriophage evolution. We therefore recommend our method for estimating the selection coefficient when the effective population size is too large to utilize the discrete Wright-Fisher model. Copyright © 2014 by the Genetics Society of America.

Using Coevolution Genetic Algorithm with Pareto Principles to Solve Project Scheduling Problem under Duration and Cost Constraints

Directory of Open Access Journals (Sweden)

Alexandr Victorovich Budylskiy

2014-06-01

Full Text Available This article considers the multicriteria optimization approach using the modified genetic algorithm to solve the project-scheduling problem under duration and cost constraints. The work contains the list of choices for solving this problem. The multicriteria optimization approach is justified here. The study describes the Pareto principles, which are used in the modified genetic algorithm. We identify the mathematical model of the project-scheduling problem. We introduced the modified genetic algorithm, the ranking strategies, the elitism approaches. The article includes the example.

Sampling inspection for the evaluation of time-dependent reliability of deteriorating systems under imperfect defect detection

International Nuclear Information System (INIS)

Kuniewski, Sebastian P.; Weide, Johannes A.M. van der; Noortwijk, Jan M. van

2009-01-01

The paper presents a sampling-inspection strategy for the evaluation of time-dependent reliability of deteriorating systems, where the deterioration is assumed to initiate at random times and at random locations. After initiation, defects are weakening the system's resistance. The system becomes unacceptable when at least one defect reaches a critical depth. The defects are assumed to initiate at random times modeled as event times of a non-homogeneous Poisson process (NHPP) and to develop according to a non-decreasing time-dependent gamma process. The intensity rate of the NHPP is assumed to be a combination of a known time-dependent shape function and an unknown proportionality constant. When sampling inspection (i.e. inspection of a selected subregion of the system) results in a number of defect initiations, Bayes' theorem can be used to update prior beliefs about the proportionality constant of the NHPP intensity rate to the posterior distribution. On the basis of a time- and space-dependent Poisson process for the defect initiation, an adaptive Bayesian model for sampling inspection is developed to determine the predictive probability distribution of the time to failure. A potential application is, for instance, the inspection of a large vessel or pipeline suffering pitting/localized corrosion in the oil industry. The possibility of imperfect defect detection is also incorporated in the model.

Ionization-induced rearrangement of defects in silicon

International Nuclear Information System (INIS)

Vinetskij, V.L.; Manojlo, M.A.; Matvijchuk, A.S.; Strikha, V.I.; Kholodar', G.A.

1988-01-01

Ionizing factor effect on defect rearrangement in silicon including centers with deep local electron levels in the p-n-transition region is considered. Deep center parameters were determined using non-steady-state capacity spectroscopy of deep levels (NCDLS) method. NCDLS spectrum measurement was performed using source p + -n - diodes and after their irradiation with 15 keV energy electrons or laser pulses. It is ascertained that in silicon samples containing point defect clusters defect rearrangement under ionizing factor effect takes place, i.e. deep level spectra are changed. This mechanism is efficient in case of silicon irradiation with subthreshold energy photons and electrons and can cause degradation of silicon semiconducting structures

Genetic complexity underlying hybrid male sterility in Drosophila.

OpenAIRE

Sawamura, Kyoichi; Roote, John; Wu, Chung-I; Yamamoto, Masa-Toshi

2004-01-01

Recent genetic analyses of closely related species of Drosophila have indicated that hybrid male sterility is the consequence of highly complex synergistic effects among multiple genes, both conspecific and heterospecific. On the contrary, much evidence suggests the presence of major genes causing hybrid female sterility and inviability in the less-related species, D. melanogaster and D. simulans. Does this contrast reflect the genetic distance between species? Or, generally, is the genetic b...

STARL -- a Program to Correct CCD Image Defects

Science.gov (United States)

Narbutis, D.; Vanagas, R.; Vansevičius, V.

We present a program tool, STARL, designed for automatic detection and correction of various defects in CCD images. It uses genetic algorithm for deblending and restoring of overlapping saturated stars in crowded stellar fields. Using Subaru Telescope Suprime-Cam images we demonstrate that the program can be implemented in the wide-field survey data processing pipelines for production of high quality color mosaics. The source code and examples are available at the STARL website.

Genetic testing in congenital heart disease:A clinical approach

Institute of Scientific and Technical Information of China (English)

Marie A Chaix; Gregor Andelfinger; Paul Khairy

2016-01-01

Congenital heart disease(CHD) is the most common type of birth defect. Traditionally, a polygenic model defined by the interaction of multiple genes and environmental factors was hypothesized to account for different forms of CHD. It is now understood that the contribution of genetics to CHD extends beyond a single unified paradigm. For example, monogenic models and chromosomal abnormalities have been associated with various syndromic and non-syndromic forms of CHD. In such instances, genetic investigation and testing may potentially play an important role in clinical care. A family tree with a detailed phenotypic description serves as the initial screening tool to identify potentially inherited defects and to guide further genetic investigation. The selection of a genetic test is contingent upon the particular diagnostic hypothesis generated by clinical examination. Genetic investigation in CHD may carry the potential to improve prognosis by yielding valuable information with regards to personalized medical care, confidence in the clinical diagnosis, and/or targeted patient followup. Moreover, genetic assessment may serve as a tool to predict recurrence risk, define the pattern of inheritance within a family, and evaluate the need for further family screening. In some circumstances, prenatal or preimplantation genetic screening could identify fetuses or embryos at high risk for CHD. Although genetics may appear to constitute a highly specialized sector of cardiology, basic knowledge regarding inheritance patterns, recurrence risks, and available screening and diagnostic tools, including their strengths and limitations, could assist the treating physician in providing sound counsel.

[The emphases and basic procedures of genetic counseling in psychotherapeutic model].

Science.gov (United States)

Zhang, Yuan-Zhi; Zhong, Nanbert

2006-11-01

The emphases and basic procedures of genetic counseling are all different with those in old models. In the psychotherapeutic model, genetic counseling will not only focus on counselees' genetic disorders and birth defects, but also their psychological problems. "Client-centered therapy" termed by Carl Rogers plays an important role in genetic counseling process. The basic procedures of psychotherapeutic model of genetic counseling include 7 steps: initial contact, introduction, agendas, inquiry of family history, presenting information, closing the session and follow-up.

Peculiarities of radiation defect formation and annealing in n-Si due to their interaction with each other and defect clusters

International Nuclear Information System (INIS)

Lugakov, P.F.; Lukyanitsa, V.V.

1984-01-01

Rearrangement processes proceeding during annealing (T/sub a/ = 50 to 500 0 C) of radiation defects in 60 Co γ-irradiated (T/sub irr/ 0 C) n-Si crystals (rho = 100 to 600 Ωcm) grown by the vacuum float-zone technique are studied. The temperature dependences of the Hall coefficient are measured. The results obtained are interpreted taking into account the interaction during annealing of vacancy-type defects (E-centres, divacancies) with each other and interstitial radiation defects (C/sub i/-C/sub s/ complexes, interstitial carbon C/sub i/). Phosphorus-two vacancies complexes, stable to T/sub a/ >= 500 0 C, are shown to be formed as a result of rearrangements and interaction of E-centres between themselves. The character of interaction of vacancy defects with interstitial ones is found to change significantly in the presence of defect clusters in the bulk of the crystal which are formed under heat treatment (T = 800 0 C, two hours) of the samples preliminary irradiated with fast neutrons (flux PHI/sub n/ = 1x10 14 to 1x10 16 cm -2 ). The peculiarities of radiation defects annealing observed in this case are explained taking into account the influence of defect clusters on the migration processes of mobile defects. Nature of radiation defects being formed at various stages of annealing is discussed. (author)

Estimates of point defect production in α-quartz using molecular dynamics simulations

Science.gov (United States)

Cowen, Benjamin J.; El-Genk, Mohamed S.

2017-07-01

Molecular dynamics (MD) simulations are performed to investigate the production of point defects in α-quartz by oxygen and silicon primary knock-on atoms (PKAs) of 0.25-2 keV. The Wigner-Seitz (WS) defect analysis is used to identify the produced vacancies, interstitials, and antisites, and the coordination defect analysis is used to identify the under and over-coordinated oxygen and silicon atoms. The defects at the end of the ballistic phase and the residual defects, after annealing, increase with increased PKA energy, and are statistically the same for the oxygen and silicon PKAs. The WS defect analysis results show that the numbers of the oxygen vacancies and interstitials (VO, Oi) at the end of the ballistic phase is the highest, followed closely by those of the silicon vacancies and interstitials (VSi, Sii). The number of the residual oxygen and silicon vacancies and interstitials are statistically the same. In addition, the under-coordinated OI and SiIII, which are the primary defects during the ballistic phase, have high annealing efficiencies (>89%). The over-coordinated defects of OIII and SiV, which are not nearly as abundant in the ballistic phase, have much lower annealing efficiencies (PKA energy.

Birth Defects

Science.gov (United States)

A birth defect is a problem that happens while a baby is developing in the mother's body. Most birth defects happen during the first 3 months of ... in the United States is born with a birth defect. A birth defect may affect how the ...

Thermodynamics of diffusion under pressure and stress: Relation to point defect mechanisms

International Nuclear Information System (INIS)

Aziz, M.J.

1997-01-01

A thermodynamic formalism is developed for illuminating the predominant point defect mechanism of self- and impurity diffusion in silicon and is used to provide a rigorous basis for point defect-based interpretation of diffusion experiments in biaxially strained epitaxial layers in the Si endash Ge system. A specific combination of the hydrostatic and biaxial stress dependences of the diffusivity is ±1 times the atomic volume, depending upon whether the predominant mechanism involves vacancies or interstitials. Experimental results for Sb diffusion in biaxially strained Si endash Ge films and ab initio calculations of the activation volume for Sb diffusion by a vacancy mechanism are in quantitative agreement with no free parameters. Key parameters are identified that must be measured or calculated for a quantitative test of interstitial-based mechanisms. copyright 1997 American Institute of Physics

A targeted sequencing panel identifies rare damaging variants in multiple genes in the cranial neural tube defect, anencephaly.

Science.gov (United States)

Ishida, M; Cullup, T; Boustred, C; James, C; Docker, J; English, C; Lench, N; Copp, A J; Moore, G E; Greene, N D E; Stanier, P

2018-04-01

Neural tube defects (NTDs) affecting the brain (anencephaly) are lethal before or at birth, whereas lower spinal defects (spina bifida) may lead to lifelong neurological handicap. Collectively, NTDs rank among the most common birth defects worldwide. This study focuses on anencephaly, which despite having a similar frequency to spina bifida and being the most common type of NTD observed in mouse models, has had more limited inclusion in genetic studies. A genetic influence is strongly implicated in determining risk of NTDs and a molecular diagnosis is of fundamental importance to families both in terms of understanding the origin of the condition and for managing future pregnancies. Here we used a custom panel of 191 NTD candidate genes to screen 90 patients with cranial NTDs (n = 85 anencephaly and n = 5 craniorachischisis) with a targeted exome sequencing platform. After filtering and comparing to our in-house control exome database (N = 509), we identified 397 rare variants (minor allele frequency, MAF < 1%), 21 of which were previously unreported and predicted damaging. This included 1 frameshift (PDGFRA), 2 stop-gained (MAT1A; NOS2) and 18 missense variations. Together with evidence for oligogenic inheritance, this study provides new information on the possible genetic causation of anencephaly. © 2017 The Authors. Clinical Genetics published by John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Point defects and irradiation in oxides: simulations at the atomic scale

International Nuclear Information System (INIS)

Crocombette, J.P.

2005-12-01

The studies done by Jean-Paul Crocombette between 1996 and 2005 in the Service de Recherches de Metallurgie Physique of the Direction de l'Energie Nucleaire in Saclay are presented in this Habilitation thesis. These works were part of the material science researches on the ageing, especially under irradiation, of oxides of interest for the nuclear industry. In this context simulation studies at the atomic scale were performed on two elementary components of ageing under irradiation : point defects and displacement cascades ; using two complementary simulation techniques : ab initio electronic structure calculations and empirical potential molecular dynamics. The first part deals with point defects : self defects (vacancies or interstitials) or hetero-atomic dopants. One first recalls the energetics of such defects in oxides, the specific features of defects calculations and the expected accuracy of these calculations. Then one presents the results obtained on uranium dioxide, oxygen in silver and amorphous silica. The second part tackles the modelling of disintegration recoil nuclei in various?displacement cascades created by crystalline matrices for actinide waste disposal. Cascade calculations give access to the amorphization mechanisms under irradiation of these materials. One thus predicts that the amorphization in zircon takes place directly in the tracks whereas in lanthanum zirconate, the amorphization proceeds through the accumulation of point defects. Finally the prospects of these studies are discussed. (author)

PAT challenges routine techniques on defect spectroscopy in material science

International Nuclear Information System (INIS)

Badawi, E.A.

2005-01-01

Atomic or Point Defects are the most simple defects in solids. Due to the small size their direct observation by the routine techniques is not possible. A single type of defects (thermal defect) was observed in the quenching process. Using the Arrhenius method and threshold method we recommended the accurate both method of treatments. The calculated values for formation enthalpies and self-diffusion using positron lifetime and Doppler broadening in a good agreement in (A356.0) and (A413.1). Specifically it is show how PAT detect defect concentrations, (formation- migration) enthalpies and grain size for the material under investigation. Most of the these data are reported

Positive and negative variations in capacitive images for given defects under varying experimental conditions

Science.gov (United States)

Li, Chen; Yin, Xiaokang; Li, Zhen; Li, Wei; Chen, Guoming

2018-04-01

Capacitive imaging (CI) technique is a novel electromagnetic NDE technique. The Quasi-static electromagnetic field from the carefully designed electrode pair will vary when the electrical properties of the sample change, leading to the possibility of imaging. It is observed that for a given specimen, the targeted features appear as different variations in capacitive images under different experimental conditions. In some cases, even opposite variations occur, which brings confusion to indication interpretation. It is thus thought interesting to embark on investigations into the cause and effects of the negative variation phenomenon. In this work, the positive and negative variations were first explained from the measurement sensitivity distribution perspective. This was then followed by a detailed analysis using finite element models in COMSOL. A parametric experimental study on a glass fiber composite plate with artificial defects was then carried out to investigate how the experimental conditions affect the variation.

Experimental and numerical response of rigid slender blocks with geometrical defects under seismic excitation

Directory of Open Access Journals (Sweden)

Mathey Charlie

2015-01-01

Full Text Available The present work investigates on the influence of small geometrical defects on the behavior of slender rigid blocks. A comprehensive experimental campaign was carried out on one of the shake tables of CEA/Saclay in France. The tested model was a massive steel block with standard manufacturing quality. Release, free oscillations tests as well as shake table tests revealed a non-negligible out-of-plane motion even in the case of apparently plane initial conditions or excitations. This motion exhibits a highly reproducible part for a short duration that was used to calibrate a numerical geometrically asymmetrical model. The stability of this model when subjected to 2 000 artificial seismic horizontal bidirectional signals was compared to the stability of a symmetrical one. This study showed that the geometrical imperfections slightly increase the rocking and overturning probabilities under bidirectional seismic excitations in a narrow range of peak ground acceleration.

Genetic aspects of hypothalamic and pituitary gland development.

Science.gov (United States)

McCabe, Mark J; Dattani, Mehul T

2014-01-01

Hypothalamo-pituitary development during embryogenesis is a highly complex process involving the interaction of a network of spatiotemporally regulated signaling molecules and transcription factors. Mutations in any of the genes encoding these components can lead to congenital hypopituitarism, which is often associated with a wide spectrum of defects affecting craniofacial/midline development. In turn, these defects can be incompatible with life, or lead to disorders encompassing holoprosencephaly (HPE) and cleft palate, and septo-optic dysplasia (SOD). In recent years, there has been increasing evidence of an overlapping genotype between this spectrum of disorders and Kallmann syndrome (KS), defined as the association of hypogonadotropic hypogonadism (HH) and anosmia. This is consistent with the known phenotypic overlap between these disorders and opens a new avenue of identifying novel genetic causes of the hypopituitarism spectrum. This chapter reviews the genetic and molecular events leading to the successful development of the hypothalamo-pituitary axis during embryogenesis, and focuses on genes in which variations/mutations occur, leading to congenital hypopituitarism and associated defects. © 2014 Elsevier B.V. All rights reserved.

A review of genome-wide approaches to study the genetic basis for spermatogenic defects.

Science.gov (United States)

Aston, Kenneth I; Conrad, Donald F

2013-01-01

Rapidly advancing tools for genetic analysis on a genome-wide scale have been instrumental in identifying the genetic bases for many complex diseases. About half of male infertility cases are of unknown etiology in spite of tremendous efforts to characterize the genetic basis for the disorder. Advancing our understanding of the genetic basis for male infertility will require the application of established and emerging genomic tools. This chapter introduces many of the tools available for genetic studies on a genome-wide scale along with principles of study design and data analysis.

Modulation of mitochondrial morphology by bioenergetics defects in primary human fibroblasts

DEFF Research Database (Denmark)

Guillery, O.; Malka, F.; Frachon, P.

2008-01-01

induced partial but significant mitochondrial fragmentation, whereas dissipation of mitochondrial membrane potential (D Psi m) provoked complete fragmentation, and glycolysis inhibition had no effect. Oxidative phosphorylation defective fibroblasts had essentially normal filamentous mitochondria under...... basal conditions, although when challenged some of them presented with mild alteration of fission or fusion efficacy. Severely defective cells disclosed complete mitochondrial fragmentation under glycolysis inhibition. In conclusion, mitochondrial morphology is modulated by D Psi m but loosely linked...... to mitochondrial oxidative phosphorylation. Its alteration by glycolysis, inhibition points to a severe oxidative phosphorylation defect. (C) 2008 Elsevier B.V. All rights reserved Udgivelsesdato: 2008/4...

Genetic architecture of retinal and macular degenerative diseases: the promise and challenges of next-generation sequencing

Science.gov (United States)

2013-01-01

Inherited retinal degenerative diseases (RDDs) display wide variation in their mode of inheritance, underlying genetic defects, age of onset, and phenotypic severity. Molecular mechanisms have not been delineated for many retinal diseases, and treatment options are limited. In most instances, genotype-phenotype correlations have not been elucidated because of extensive clinical and genetic heterogeneity. Next-generation sequencing (NGS) methods, including exome, genome, transcriptome and epigenome sequencing, provide novel avenues towards achieving comprehensive understanding of the genetic architecture of RDDs. Whole-exome sequencing (WES) has already revealed several new RDD genes, whereas RNA-Seq and ChIP-Seq analyses are expected to uncover novel aspects of gene regulation and biological networks that are involved in retinal development, aging and disease. In this review, we focus on the genetic characterization of retinal and macular degeneration using NGS technology and discuss the basic framework for further investigations. We also examine the challenges of NGS application in clinical diagnosis and management. PMID:24112618

Anemia of the Belgrade rat: evidence for defective membrane transport of iron

International Nuclear Information System (INIS)

Bowen, B.J.; Morgan, E.H.

1987-01-01

The mechanisms underlying the impaired utilization of transferrin-bound iron by erythroid cells in the anemia of the Belgrade laboratory rat were investigated using reticulocytes from homozygous anemic animals and transferrin labeled with 59 Fe and 125 I. The results were compared with those obtained using reticulocytes from phenylhydrazine-treated rats and iron-deficient rats. Each step in the iron uptake mechanism was investigated, ie, transferrin-receptor interaction, transferrin endocytosis, iron release from transferrin, and transferrin exocytosis. Although there were quantitative differences, no fundamental difference was found in any of the abovementioned aspects of cellular function when the reticulocytes from Belgrade rats were compared with those from iron-deficient animals. The basic defect in the Belgrade reticulocytes must therefore reside in subsequent steps in iron uptake, after it is released from transferrin within endocytotic vesicles, ie, in the mechanism by which it is transferred across the lining membrane of the vesicles into the cell cytosol. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of reticulocyte ghosts extracts demonstrated a prominent protein band of mol wt 69,000 that was absent or present only in low concentration extracts from the other two types of reticulocytes. This may be a result of the genetic defect

Xenon Defects in Uranium Dioxide From First Principles and Interatomic Potentials

Science.gov (United States)

Thompson, Alexander

In this thesis, we examine the defect energetics and migration energies of xenon atoms in uranium dioxide (UO2) from first principles and interatomic potentials. We also parameterize new, accurate interatomic potentials for xenon and uranium dioxide. To achieve accurate energetics and provide a foundation for subsequent calculations, we address difficulties in finding consistent energetics within Hubbard U corrected density functional theory (DFT+U). We propose a method of slowly ramping the U parameter in order to guide the calculation into low energy orbital occupations. We find that this method is successful for a variety of materials. We then examine the defect energetics of several noble gas atoms in UO2 for several different defect sites. We show that the energy to incorporate large noble gas atoms into interstitial sites is so large that it is energetically favorable for a Schottky defect cluster to be created to relieve the strain. We find that, thermodynamically, xenon will rarely ever be in the interstitial site of UO2. To study larger defects associated with the migration of xenon in UO 2, we turn to interatomic potentials. We benchmark several previously published potentials against DFT+U defect energetics and migration barriers. Using a combination of molecular dynamics and nudged elastic band calculations, we find a new, low energy migration pathway for xenon in UO2. We create a new potential for xenon that yields accurate defect energetics. We fit this new potential with a method we call Iterative Potential Refinement that parameterizes potentials to first principles data via a genetic algorithm. The potential finds accurate energetics for defects with relatively low amounts of strain (xenon in defect clusters). It is important to find accurate energetics for these sorts of low-strain defects because they essentially represent small xenon bubbles. Finally, we parameterize a new UO2 potential that simultaneously yields accurate vibrational properties

Chaski, a novel Drosophila lactate/pyruvate transporter required in glia cells for survival under nutritional stress.

Science.gov (United States)

Delgado, María Graciela; Oliva, Carlos; López, Estefanía; Ibacache, Andrés; Galaz, Alex; Delgado, Ricardo; Barros, L Felipe; Sierralta, Jimena

2018-01-19

The intercellular transport of lactate is crucial for the astrocyte-to-neuron lactate shuttle (ANLS), a model of brain energetics according to which neurons are fueled by astrocytic lactate. In this study we show that the Drosophila chaski gene encodes a monocarboxylate transporter protein (MCT/SLC16A) which functions as a lactate/pyruvate transporter, as demonstrated by heterologous expression in mammalian cell culture using a genetically encoded FRET nanosensor. chaski expression is prominent in the Drosophila central nervous system and it is particularly enriched in glia over neurons. chaski mutants exhibit defects in a high energy demanding process such as synaptic transmission, as well as in locomotion and survival under nutritional stress. Remarkably, locomotion and survival under nutritional stress defects are restored by chaski expression in glia cells. Our findings are consistent with a major role for intercellular lactate shuttling in the brain metabolism of Drosophila.

Genetics Home Reference: congenital bile acid synthesis defect type 1

Science.gov (United States)

... result in softening and weakening of the bones ( rickets ) in some individuals. If left untreated, congenital bile ... Encyclopedia: Cholestasis Health Topic: Liver Diseases Health Topic: Rickets Genetic and Rare Diseases Information Center (1 link) ...

Preventive program of birth defects: incidence of anencephaly in Maracaibo, Venezuela. 1993-1996 period

International Nuclear Information System (INIS)

Moreno Fuenmayor, H; Valera, V; Socorro Candanoza, L; Bracho, A; Herrera, M; Rodriguez, Z; Concho, E

1996-01-01

Incidence of anencephaly in the State of Zulia, and specifically in the Eastern Coast of Lake Maracaibo, an oil exploitation area, has been declared high since the beginning of the 80's, coincident with the generalized use of ultrasound as a diagnostic tool for fetal evaluation. Through the Birth Defects Preventive Program, established at the Hospital Chiquinquira in Maracaibo, we have developed a fourfold strategy for the study of birth defects: i) analysis of more than 32,332 ultrasound evaluations within the Ultrasound Service, between 1993 and 1996, ii) a case-control malformation registry beginning in 1995, iii) a study of malformed stillbirths at the Pathology Service, observed after 4232 deliveries within this hospital, and iv) a registry of over 638 mothers with high risk pregnancy for fetal defects detected at the prenatal clinic and carried out at the Perinatal Medical Genetics Service. As a reference population we study 345 medical histories obtained from the Medical Genetics and Prenatal Diagnostic Service at Hospital Coromoto, and oil companies related medical facility. This approach has led us to conclude that the incidence of anencephaly in the State of Zulia is 0.75/1000, significantly similar to that expected for most populations

Adaptive genetic potential of coniferous forest tree species under climate change: implications for sustainable forest management

Science.gov (United States)

Mihai, Georgeta; Birsan, Marius-Victor; Teodosiu, Maria; Dumitrescu, Alexandru; Daia, Mihai; Mirancea, Ionel; Ivanov, Paula; Alin, Alexandru

2017-04-01

Mountain ecosystems are extremely vulnerable to climate change. The real potential for adaptation depends upon the existence of a wide genetic diversity in trees populations, upon the adaptive genetic variation, respectively. Genetic diversity offers the guarantee that forest species can survive, adapt and evolve under the influence of changing environmental conditions. The aim of this study is to evaluate the genetic diversity and adaptive genetic potential of two local species - Norway spruce and European silver fir - in the context of regional climate change. Based on data from a long-term provenance experiments network and climate variables spanning over more than 50 years, we have investigated the impact of climatic factors on growth performance and adaptation of tree species. Our results indicate that climatic and geographic factors significantly affect forest site productivity. Mean annual temperature and annual precipitation amount were found to be statistically significant explanatory variables. Combining the additive genetic model with the analysis of nuclear markers we obtained different images of the genetic structure of tree populations. As genetic indicators we used: gene frequencies, genetic diversity, genetic differentiation, genetic variance, plasticity. Spatial genetic analyses have allowed identifying the genetic centers holding high genetic diversity which will be valuable sources of gene able to buffer the negative effects of future climate change. Correlations between the marginal populations and in the optimal vegetation, between the level of genetic diversity and ecosystem stability, will allow the assessment of future risks arising from current genetic structure. Therefore, the strategies for sustainable forest management have to rely on the adaptive genetic variation and local adaptation of the valuable genetic resources. This work was realized within the framework of the project GENCLIM (Evaluating the adaptive potential of the main

Lattice defects in semiconducting Hg/1-x/Cd/x/Te alloys. III - Defect structure of undoped Hg0.6Cd0.4Te

Science.gov (United States)

Vydyanath, H. R.; Donovan, J. D.; Nelson, D. A.

1981-01-01

Hall effect measurements were carried out on undoped Hg0.6Cd0.4Te crystals quenched to room temperature subsequent to equilibration at temperatures varying from 450 to 720 C under various partial pressures of Hg. The variation of the hole concentration as a function of the partial pressure of Hg indicates that the native acceptor defects are doubly ionized. Native donor defects are found to be negligible in concentration and the p-type to n-type conversion is shown to be due to residual donors and not due to native donor defects. Thermodynamic constant for the incorporation of the doubly ionized native acceptor defect has been established.

White Matter Hyperintensities Are Under Strong Genetic Influence.

Science.gov (United States)

Sachdev, Perminder S; Thalamuthu, Anbupalam; Mather, Karen A; Ames, David; Wright, Margaret J; Wen, Wei

2016-06-01

The genetic basis of white matter hyperintensities (WMH) is still unknown. This study examines the heritability of WMH in both sexes and in different brain regions, and the influence of age. Participants from the Older Australian Twins Study were recruited (n=320; 92 monozygotic and 68 dizygotic pairs) who volunteered for magnetic resonance imaging scans and medical assessments. Heritability, that is, the ratio of the additive genetic variance to the total phenotypic variance, was estimated using the twin design. Heritability was high for total WMH volume (0.76), and for periventricular WMH (0.64) and deep WMH (0.77), and varied from 0.18 for the cerebellum to 0.76 for the occipital lobe. The genetic correlation between deep and periventricular WMH regions was 0.85, with one additive genetics factor accounting for most of the shared variance. Heritability was consistently higher in women in the cerebral regions. Heritability in deep but not periventricular WMH declined with age, in particular after the age of 75. WMH have a strong genetic influence but this is not uniform through the brain, being higher for deep than periventricular WMH and in the cerebral regions. The genetic influence is higher in women, and there is an age-related decline, most markedly for deep WMH. The data suggest some heterogeneity in the pathogenesis of WMH for different brain regions and for men and women. © 2016 American Heart Association, Inc.

Highly effective SNP-based association mapping and management of recessive defects in livestock

DEFF Research Database (Denmark)

Charlier, Carole; Coppieters, Wouter; Rollin, Frédéric

2008-01-01

The widespread use of elite sires by means of artificial insemination in livestock breeding leads to the frequent emergence of recessive genetic defects, which cause significant economic and animal welfare concerns. Here we show that the availability of genome-wide, high-density SNP panels, combi...

CARTILAGE CONSTRUCTS ENGINEERED FROM CHONDROCYTES OVEREXPRESSING IGF-I IMPROVE THE REPAIR OF OSTEOCHONDRAL DEFECTS IN A RABBIT MODEL

Science.gov (United States)

Madry, Henning; Kaul, Gunter; Zurakowski, David; Vunjak-Novakovic, Gordana; Cucchiarini, Magali

2015-01-01

Tissue engineering combined with gene therapy is a promising approach for promoting articular cartilage repair. Here, we tested the hypothesis that engineered cartilage with chondrocytes over expressing a human insulin-like growth factor I (IGF-I) gene can enhance the repair of osteochondral defects, in a manner dependent on the duration of cultivation. Genetically modified chondrocytes were cultured on biodegradable polyglycolic acid scaffolds in dynamic flow rotating bioreactors for either 10 or 28 d. The resulting cartilaginous constructs were implanted into osteochondral defects in rabbit knee joints. After 28 weeks of in vivo implantation, immunoreactivity to ß-gal was detectable in the repair tissue of defects that received lacZ constructs. Engineered cartilaginous constructs based on IGF-I-over expressing chondrocytes markedly improved osteochondral repair compared with control (lacZ) constructs. Moreover, IGF-I constructs cultivated for 28 d in vitro significantly promoted osteochondral repair vis-à-vis similar constructs cultivated for 10 d, leading to significantly decreased osteoarthritic changes in the cartilage adjacent to the defects. Hence, the combination of spatially defined overexpression of human IGF-I within a tissue-engineered construct and prolonged bioreactor cultivation resulted in most enhanced articular cartilage repair and reduction of osteoarthritic changes in the cartilage adjacent to the defect. Such genetically enhanced tissue engineering provides a versatile tool to evaluate potential therapeutic genes in vivo and to improve our comprehension of the development of the repair tissue within articular cartilage defects. Insights gained with additional exploration using this model may lead to more effective treatment options for acute cartilage defects. PMID:23588785

Cartilage constructs engineered from chondrocytes overexpressing IGF-I improve the repair of osteochondral defects in a rabbit model

Directory of Open Access Journals (Sweden)

H Madry

2013-04-01

Full Text Available Tissue engineering combined with gene therapy is a promising approach for promoting articular cartilage repair. Here, we tested the hypothesis that engineered cartilage with chondrocytes overexpressing a human insulin-like growth factor I (IGF-I gene can enhance the repair of osteochondral defects, in a manner dependent on the duration of cultivation. Genetically modified chondrocytes were cultured on biodegradable polyglycolic acid scaffolds in dynamic flow rotating bioreactors for either 10 or 28 d. The resulting cartilaginous constructs were implanted into osteochondral defects in rabbit knee joints. After 28 weeks of in vivo implantation, immunoreactivity to ß-gal was detectable in the repair tissue of defects that received lacZ constructs. Engineered cartilaginous constructs based on IGF-I-overexpressing chondrocytes markedly improved osteochondral repair compared with control (lacZ constructs. Moreover, IGF-I constructs cultivated for 28 d in vitro significantly promoted osteochondral repair vis-à-vis similar constructs cultivated for 10 d, leading to significantly decreased osteoarthritic changes in the cartilage adjacent to the defects. Hence, the combination of spatially defined overexpression of human IGF-I within a tissue-engineered construct and prolonged bioreactor cultivation resulted in most enhanced articular cartilage repair and reduction of osteoarthritic changes in the cartilage adjacent to the defect. Such genetically enhanced tissue engineering provides a versatile tool to evaluate potential therapeutic genes in vivo and to improve our comprehension of the development of the repair tissue within articular cartilage defects. Insights gained with additional exploration using this model may lead to more effective treatment options for acute cartilage defects.

Metastable defect response in CZTSSe from admittance spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Koeper, Mark J.; Hages, Charles J.; Li, Jian V.; Levi, Dean; Agrawal, Rakesh

2017-10-02

Admittance spectroscopy is a useful tool used to study defects in semiconductor materials. However, metastable defect responses in non-ideal semiconductors can greatly impact the measurement and therefore the interpretation of results. Here, admittance spectroscopy was performed on Cu2ZnSn(S,Se)4 where metastable defect response is illustrated due to the trapping of injected carriers into a deep defect state. To investigate the metastable response, admittance measurements were performed under electrically and optically relaxed conditions in comparison to a device following a low level carrier-injection pretreatment. The relaxed measurement demonstrates a single capacitance signature while two capacitance signatures are observed for the device measured following carrier-injection. The deeper level signature, typically reported for kesterites, is activated by charge trapping following carrier injection. Both signatures are attributed to bulk level defects. The significant metastable response observed on kesterites due to charge trapping obscures accurate interpretation of defect levels from admittance spectroscopy and indicates that great care must be taken when performing and interpreting this measurement on non-ideal devices.

Experience from large scale use of the EuroGenomics custom SNP chip in cattle

DEFF Research Database (Denmark)

Boichard, Didier A; Boussaha, Mekki; Capitan, Aurélien

2018-01-01

This article presents the strategy to evaluate candidate mutations underlying QTL or responsible for genetic defects, based upon the design and large-scale use of the Eurogenomics custom SNP chip set up for bovine genomic selection. Some variants under study originated from mapping genetic defect...

Reduction in Defect Content in ODS Alloys

Energy Technology Data Exchange (ETDEWEB)

Ritherdon, J.; Jones, A.R.

2000-02-01

The work detailed within this report is a continuation of earlier work that was carried out under contract number IDX-SY382V. The earlier work comprised a literature review of the sources and types of defects found principally in Fe-based ODS alloys together with a series of experiments designed to identify defects in ODS Fe{sub 3}Al material and recommend methods of defect reduction. Defects found in the Mechanically Alloyed (MA) ODS Fe{sub 3}Al included regions of incomplete MA, porosity, intrusions and fine-grained stringers. Some defects tended to be found in association with one another e.g. intrusions and fine-grained stringers. Preliminary powder separation experiments were also performed. The scope and objectives of the present work were laid out in the technical proposal ``Reduction in Defect Content in ODS Alloys--II'' which formed the basis of amendment 3 of the current contract. The current studies were devised in the context of the preceding work with a view to extending and concluding certain experiments while exploring new avenues of investigation of defect control and reduction where appropriate. All work proposed was within the context of achieving an ODS Fe{sub 3}Al alloy of improved overall quality and potential creep performance (particularly) in the consolidated, release condition. The interim outturn of the experimental work performed is also reported.

Capture of impurity atoms by defects and the distribution of the complexes under ion bormbardment of growing films

International Nuclear Information System (INIS)

Radzhabov, T.D.; Iskanderova, Z.A.; Arutyunova, E.O.; Samigulin, K.R.

1982-01-01

Theoretical study of capture of impurity gas atoms with defects during ion introduction of the impurity in the process of film growth with simultaneous diffusion has been carried out. Concentration profiles of forned impurity-defect complexes have been calculated analytically and numerically by means of a computer in film depth and in a substrate; basic peculiarities of impurity component formation captured with defects in a wide range of changing basic experimental parameters have been revealed. Effect of impurity capture with defects on amount and distribution of total concentration of impurity atoms and intensity of complete absorption of bombarding ions in films have been analyzed. Shown is a possibility for producing films with a high concentration level and almost uniform distribution of the impurity-defect complexes for real, achievable an experiment, values of process parameters as well as a possibility for increasing complete absorption of gaseous impurity wiht concentration growth of capture defects-traps

Complex genetics of glaucoma: defects in CYP1B1, and not MYOC ...

Indian Academy of Sciences (India)

wide, affecting almost 60 million people (Quigley and Bro- man 2006). Defects ... Analysis of the family mem- ... both parents of the proband do not show any symptom of. POAG ... †These authors contributed equally to the work. .... stage of life.

Production and stability of radiation-induced defects in MgAl2O4 under electronic excitation

International Nuclear Information System (INIS)

Yasuda, K.; Yamamoto, T.; Seki, S.; Shiiyama, K.; Matsumura, S.

2008-01-01

This paper investigates the formation process of radiation-induced defects in magnesium aluminate spinel and their stability using transmission electron microscopy, with emphasis on the effects of electronic excitation. Small interstitial-type dislocation loops disappeared under electron-induced electronic excitation. The elimination rate of the loops was found to be one order higher than for α-alumina. The disappearance of dislocation loops by a dissociation mechanism into isolated interstitials is discussed through analysis of the growth-and-shrink process of the loops. HARECXS analysis on cross section specimens irradiated with 350 MeV Au ions has shown the progress of cation disordering along ion tracks to be a function of electronic stopping power, (dE/dx) e . Cations were found to exchange their sites toward a random configuration. Such disordering appears from (dE/dx) e = 10 keV/nm, and increases in size with increasing (dE/dx) e to reach nearly 10 nm in diameter at 30 keV/nm, under an assumption of a fully disordered configuration

Genetic testing in congenital heart disease: A clinical approach

Science.gov (United States)

Chaix, Marie A; Andelfinger, Gregor; Khairy, Paul

2016-01-01

Congenital heart disease (CHD) is the most common type of birth defect. Traditionally, a polygenic model defined by the interaction of multiple genes and environmental factors was hypothesized to account for different forms of CHD. It is now understood that the contribution of genetics to CHD extends beyond a single unified paradigm. For example, monogenic models and chromosomal abnormalities have been associated with various syndromic and non-syndromic forms of CHD. In such instances, genetic investigation and testing may potentially play an important role in clinical care. A family tree with a detailed phenotypic description serves as the initial screening tool to identify potentially inherited defects and to guide further genetic investigation. The selection of a genetic test is contingent upon the particular diagnostic hypothesis generated by clinical examination. Genetic investigation in CHD may carry the potential to improve prognosis by yielding valuable information with regards to personalized medical care, confidence in the clinical diagnosis, and/or targeted patient follow-up. Moreover, genetic assessment may serve as a tool to predict recurrence risk, define the pattern of inheritance within a family, and evaluate the need for further family screening. In some circumstances, prenatal or preimplantation genetic screening could identify fetuses or embryos at high risk for CHD. Although genetics may appear to constitute a highly specialized sector of cardiology, basic knowledge regarding inheritance patterns, recurrence risks, and available screening and diagnostic tools, including their strengths and limitations, could assist the treating physician in providing sound counsel. PMID:26981213

A criterion and mechanism for power ramp defects

International Nuclear Information System (INIS)

Garlick, A.; Gravenor, J.G.

1978-02-01

The problem of power ramp defects in water reactor fuel pins is discussed in relation to results recently obtained from ramp experiments in the Steam Generating Heavy Water Reactor. Cladding cracks in the defected fuel pins were similar, both macro- and micro structurally, to those in unirradiated Zircaloy exposed to iodine stress-corrosion cracking (scc) conditions. Furthermore, when the measured stress levels for scc in short-term tests were taken as a criterion for ramp defects, UK fuel modelling codes were found to give a useful indication of defect probability under reactor service conditions. The likelihood of sticking between fuel and cladding is discussed and evidence presented which suggests that even at power a degree of adhesion may be expected in some fuel pins. The ramp defect mechanism is discussed in terms of fission product scc, initiation being by intergranular penetration and propagation by cleavage when suitably orientated grains are exposed to large dilatational stresses ahead of the main crack. (author)

Defects of the Glycinergic Synapse in Zebrafish

Science.gov (United States)

Ogino, Kazutoyo; Hirata, Hiromi

2016-01-01

Glycine mediates fast inhibitory synaptic transmission. Physiological importance of the glycinergic synapse is well established in the brainstem and the spinal cord. In humans, the loss of glycinergic function in the spinal cord and brainstem leads to hyperekplexia, which is characterized by an excess startle reflex to sudden acoustic or tactile stimulation. In addition, glycinergic synapses in this region are also involved in the regulation of respiration and locomotion, and in the nociceptive processing. The importance of the glycinergic synapse is conserved across vertebrate species. A teleost fish, the zebrafish, offers several advantages as a vertebrate model for research of glycinergic synapse. Mutagenesis screens in zebrafish have isolated two motor defective mutants that have pathogenic mutations in glycinergic synaptic transmission: bandoneon (beo) and shocked (sho). Beo mutants have a loss-of-function mutation of glycine receptor (GlyR) β-subunit b, alternatively, sho mutant is a glycinergic transporter 1 (GlyT1) defective mutant. These mutants are useful animal models for understanding of glycinergic synaptic transmission and for identification of novel therapeutic agents for human diseases arising from defect in glycinergic transmission, such as hyperekplexia or glycine encephalopathy. Recent advances in techniques for genome editing and for imaging and manipulating of a molecule or a physiological process make zebrafish more attractive model. In this review, we describe the glycinergic defective zebrafish mutants and the technical advances in both forward and reverse genetic approaches as well as in vivo visualization and manipulation approaches for the study of the glycinergic synapse in zebrafish. PMID:27445686

Selection and Characterization of Palmitic Acid Responsive Patients with an OXPHOS Complex I Defect

Directory of Open Access Journals (Sweden)

Tom E. J. Theunissen

2017-10-01

Full Text Available Mitochondrial disorders are genetically and clinically heterogeneous, mainly affecting high energy-demanding organs due to impaired oxidative phosphorylation (OXPHOS. Currently, effective treatments for OXPHOS defects, with complex I deficiency being the most prevalent, are not available. Yet, clinical practice has shown that some complex I deficient patients benefit from a high-fat or ketogenic diet, but it is unclear how these therapeutic diets influence mitochondrial function and more importantly, which complex I patients could benefit from such treatment. Dietary studies in a complex I deficient patient with exercise intolerance showed increased muscle endurance on a high-fat diet compared to a high-carbohydrate diet. We performed whole-exome sequencing to characterize the genetic defect. A pathogenic homozygous p.G212V missense mutation was identified in the TMEM126B gene, encoding an early assembly factor of complex I. A complementation study in fibroblasts confirmed that the p.G212V mutation caused the complex I deficiency. The mechanism turned out to be an incomplete assembly of the peripheral arm of complex I, leading to a decrease in the amount of mature complex I. The patient clinically improved on a high-fat diet, which was supported by the 25% increase in maximal OXPHOS capacity in TMEM126B defective fibroblast by the saturated fatty acid palmitic acid, whereas oleic acid did not have any effect in those fibroblasts. Fibroblasts of other patients with a characterized complex I gene defect were tested in the same way. Patient fibroblasts with complex I defects in NDUFS7 and NDUFAF5 responded to palmitic acid, whereas ACAD9, NDUFA12, and NDUFV2 defects were non-responding. Although the data are too limited to draw a definite conclusion on the mechanism, there is a tendency that protein defects involved in early assembly complexes, improve with palmitic acid, whereas proteins defects involved in late assembly, do not. Our data show at

[SOS response of DNA repair and genetic cell instability under hypoxic conditions].

Science.gov (United States)

Vasil'eva, S V; Strel'tsova, D A

2011-01-01

The SOS DNA repair pathway is induced in E. coli as a multifunctional cell response to a wide variety of signals: UV, X or gamma-irradiation, mitomycin C or nalidixic acid treatment, thymine starvation, etc. Triggering of the system can be used as a general and early sign of DNA damage. Additionally, the SOS-response is known to be an "error-prone" DNA repair pathway and one of the sources of genetic instability. Hypoxic conditions are established to be the major factor of genetic instability as well. In this paper we for the first time studied the SOS DNA repair response under hypoxic conditions induced by the well known aerobic SOS-inducers. The SOS DNA repair response was examined as a reaction of E. coli PQ37 [sfiA::lacZ] cells to UVC, NO-donating agents and 4NQO. Here we provide evidence that those agents were able to induce the SOS DNA repair response in E. coli at anaerobic growth conditions. The process does not depend on the transcriptional activity of the universal protein of E. col anaerobic growth Fnr [4Fe-4S]2+ or can not be referred to as an indicator of genetic instability in hypoxic conditions.

Correlation and regression analyses of genetic effects for different types of cells in mammals under radiation and chemical treatment

International Nuclear Information System (INIS)

Slutskaya, N.G.; Mosseh, I.B.

2006-01-01

Data about genetic mutations under radiation and chemical treatment for different types of cells have been analyzed with correlation and regression analyses. Linear correlation between different genetic effects in sex cells and somatic cells have found. The results may be extrapolated on sex cells of human and mammals. (authors)

Bone tissue ultrastructural defects in a mouse model for osteogenesis imperfecta: a Raman spectroscopy study

Science.gov (United States)

Chen, Tsoching; Kozloff, Kenneth M.; Goldstein, Steven A.; Morris, Michael D.

2004-07-01

Osteogenesis imperfecta (OI) is genetic defect in which the genes that code for the α1(I) or α2(I) chains of type I collagen are defective. The defects often result in substitution of a bulky amino acid for glycine, causing formation of collagen that can not form the normal triple helix. Depending on the details of the defects, the outcomes range from controllable to lethal. This study focuses on OI type IV, a more common and moderately severe form of the disease. People with the disease have a substantial increase in the risk and rate of fracture. We examine the spectroscopic consequences of these defects, using a mouse model (BRTL) that mimics OI type IV. We compare Raman images from tibial cortical tissue of wild-type mice and BRTL mice with single copy of mutation and show that both mineral to matrix ratios and collagen inter-fibril cross-links are different in wild-type and mutant mice.

The Number of Candidate Variants in Exome Sequencing for Mendelian Disease under No Genetic Heterogeneity

Directory of Open Access Journals (Sweden)

Jo Nishino

2013-01-01

Full Text Available There has been recent success in identifying disease-causing variants in Mendelian disorders by exome sequencing followed by simple filtering techniques. Studies generally assume complete or high penetrance. However, there are likely many failed and unpublished studies due in part to incomplete penetrance or phenocopy. In this study, the expected number of candidate single-nucleotide variants (SNVs in exome data for autosomal dominant or recessive Mendelian disorders was investigated under the assumption of “no genetic heterogeneity.” All variants were assumed to be under the “null model,” and sample allele frequencies were modeled using a standard population genetics theory. To investigate the properties of pedigree data, full-sibs were considered in addition to unrelated individuals. In both cases, particularly regarding full-sibs, the number of SNVs remained very high without controls. The high efficacy of controls was also confirmed. When controls were used with a relatively large total sample size (e.g., N=20, 50, filtering incorporating of incomplete penetrance and phenocopy efficiently reduced the number of candidate SNVs. This suggests that filtering is useful when an assumption of no “genetic heterogeneity” is appropriate and could provide general guidelines for sample size determination.

47 CFR 25.112 - Defective applications.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Defective applications. 25.112 Section 25.112 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS... internationally for such operations under the Radio Regulations of the International Telecommunication Union. (b...

Shared activity patterns arising at genetic susceptibility loci reveal underlying genomic and cellular architecture of human disease.

Science.gov (United States)

Baillie, J Kenneth; Bretherick, Andrew; Haley, Christopher S; Clohisey, Sara; Gray, Alan; Neyton, Lucile P A; Barrett, Jeffrey; Stahl, Eli A; Tenesa, Albert; Andersson, Robin; Brown, J Ben; Faulkner, Geoffrey J; Lizio, Marina; Schaefer, Ulf; Daub, Carsten; Itoh, Masayoshi; Kondo, Naoto; Lassmann, Timo; Kawai, Jun; Mole, Damian; Bajic, Vladimir B; Heutink, Peter; Rehli, Michael; Kawaji, Hideya; Sandelin, Albin; Suzuki, Harukazu; Satsangi, Jack; Wells, Christine A; Hacohen, Nir; Freeman, Thomas C; Hayashizaki, Yoshihide; Carninci, Piero; Forrest, Alistair R R; Hume, David A

2018-03-01

Genetic variants underlying complex traits, including disease susceptibility, are enriched within the transcriptional regulatory elements, promoters and enhancers. There is emerging evidence that regulatory elements associated with particular traits or diseases share similar patterns of transcriptional activity. Accordingly, shared transcriptional activity (coexpression) may help prioritise loci associated with a given trait, and help to identify underlying biological processes. Using cap analysis of gene expression (CAGE) profiles of promoter- and enhancer-derived RNAs across 1824 human samples, we have analysed coexpression of RNAs originating from trait-associated regulatory regions using a novel quantitative method (network density analysis; NDA). For most traits studied, phenotype-associated variants in regulatory regions were linked to tightly-coexpressed networks that are likely to share important functional characteristics. Coexpression provides a new signal, independent of phenotype association, to enable fine mapping of causative variants. The NDA coexpression approach identifies new genetic variants associated with specific traits, including an association between the regulation of the OCT1 cation transporter and genetic variants underlying circulating cholesterol levels. NDA strongly implicates particular cell types and tissues in disease pathogenesis. For example, distinct groupings of disease-associated regulatory regions implicate two distinct biological processes in the pathogenesis of ulcerative colitis; a further two separate processes are implicated in Crohn's disease. Thus, our functional analysis of genetic predisposition to disease defines new distinct disease endotypes. We predict that patients with a preponderance of susceptibility variants in each group are likely to respond differently to pharmacological therapy. Together, these findings enable a deeper biological understanding of the causal basis of complex traits.

Institute of Genetics. Progress report on research and development activities in 1994

International Nuclear Information System (INIS)

1995-01-01

The Institute of Genetics performed R and D work on the following subjects: Effects induced by radiation, oxygen radicals, and chemical mutagens; Regulation of genetic activity; Mechanisms of tumor spreading; Genetic models of mice for simulation of defects in man; p53 and the 'dioxin' receptor as targets of toxic agents. The research results achieved in the reporting period are reviewed and explained. (orig./MG) [de

Reduced α-MSH Underlies Hypothalamic ER-Stress-Induced Hepatic Gluconeogenesis.

Science.gov (United States)

Schneeberger, Marc; Gómez-Valadés, Alicia G; Altirriba, Jordi; Sebastián, David; Ramírez, Sara; Garcia, Ainhoa; Esteban, Yaiza; Drougard, Anne; Ferrés-Coy, Albert; Bortolozzi, Analía; Garcia-Roves, Pablo M; Jones, John G; Manadas, Bruno; Zorzano, Antonio; Gomis, Ramon; Claret, Marc

2015-07-21

Alterations in ER homeostasis have been implicated in the pathophysiology of obesity and type-2 diabetes (T2D). Acute ER stress induction in the hypothalamus produces glucose metabolism perturbations. However, the neurobiological basis linking hypothalamic ER stress with abnormal glucose metabolism remains unknown. Here, we report that genetic and induced models of hypothalamic ER stress are associated with alterations in systemic glucose homeostasis due to increased gluconeogenesis (GNG) independent of body weight changes. Defective alpha melanocyte-stimulating hormone (α-MSH) production underlies this metabolic phenotype, as pharmacological strategies aimed at rescuing hypothalamic α-MSH content reversed this phenotype at metabolic and molecular level. Collectively, our results posit defective α-MSH processing as a fundamental mediator of enhanced GNG in the context of hypothalamic ER stress and establish α-MSH deficiency in proopiomelanocortin (POMC) neurons as a potential contributor to the pathophysiology of T2D. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

First-Principles Investigations of Defects in Minerals

Science.gov (United States)

Verma, Ashok K.

2011-07-01

ions vary largely among different types of defects. In particular, the O-defects introduce localized electronic states. For Mg2SiO4 polymorphs native and protonic point defects were investigated upto 30 GPa. The Mg2+-Frenkel defects in forsterite and MgO pseudo-Schottky defects in wadsleyite and ringwoodite are energetically most favorable. Mg migration is easiest in forsterite and ringwoodite whereas Si migration is easiest in wadsleyite. Protons show substantially effect on structural transition pressures and PV equations-of-states. In our work on MgO, we showed that the point defect formation is easier in grain boundary interfacial regions than in bulk and pressure increasingly stabilizes interfacial vacancies relative to bulk thereby causing as enhancement in the vacancy concentrations. Symmetric tilt grain boundaries show structural phase transitions to asymmetric tilt grain boundaries under pressure.

Risk factors of neural tube defects: A reality of Batna region in Algeria

Directory of Open Access Journals (Sweden)

Romyla Bourouba

2018-07-01

Full Text Available Background: Neural tube defects (NTDs are severe birth defects, with genetic and/or environmental risk factors. Aim: The objective of this study was to analyze data on NTDs cases at the Batna Maternity Hospital and to investigate some environmental and two genetic risk factors suspected in the etiology of NTDs. Subjects and methods: This study was conducted on 82 healthy participants and 48 mothers with an NTD child. Peripheral blood samples were collected, in EDTA tubes and frozen at −20 °C until DNA extraction by conventional method. Genetic analysis of methylene tetrahydrofolate reductase C677T polymorphism was determined by real time PCR, while cystathionine-beta-synthase 844 insertion was investigated by traditional PCR. Chi-square analyses were used to evaluate differences in the distribution of data. The odds-ratio was also calculated. A P-value less than 0.05 were significant. Results: The incidence of NTD in Batna region was 1.58 per 1000 births. The rate of NTD was significantly higher in females than males, highest affected NTD newborn’s was observed in mothers aged between 25 and 29 years and the consanguinity among all NTD cases was 30%. Data showed no significant association of NTDs with personal education, obesity, diabetes, but regarding folic acid consumption, about 86% of NTD’s mothers in our region didn’t take pre-conceptional supplementation with this vitamin .Genetic factors results didn't show a significant association of NTDs with specific mutations of the variant C677T MTHFR, and no gene-gene interaction of CBS insertion and C677T polymorphism was found, despite a significant difference in heterozygote frequency of CBS 844ins68 genotype between NTD’s mothers and controls, OR: 2.85(1.18–6.88. Conclusion: NTD represents a real public health problem in Batna, Algeria. Various genetic and/or nutritional factors are implicated, although the mechanism is not clear. We suggest that further research should continue

Risk factors and birth prevalence of birth defects and inborn errors of ...

African Journals Online (AJOL)

Children with any birth defect or metabolic errors of metabolism at birth or in the neonatology section were our sample for study. Control group was randomly selected from the cases with normal live births. Blood tests were performed for children suspected to suffer from genetic blood disorders. The principal BD as per the ...

The semiconductor doping with radiation defects via proton and alpha-particle irradiation. Review

CERN Document Server

Kozlov, V A

2001-01-01

Paper presents an analytical review devoted to semiconductor doping with radiation defects resulted from irradiation by light ions, in particular, by protons and alpha-particles. One studies formation of radiation defects in silicon, gallium arsenide and indium phosphide under light ion irradiation. One analyzes effect of proton and alpha-particle irradiation on electric conductivity of the above-listed semiconducting materials. Semiconductor doping with radiation defects under light ion irradiation enables to control their electrophysical properties and to design high-speed opto-, micro- and nanoelectronic devices on their basis

Immobile defects in ferroelastic walls: Wall nucleation at defect sites

Science.gov (United States)

He, X.; Salje, E. K. H.; Ding, X.; Sun, J.

2018-02-01

Randomly distributed, static defects are enriched in ferroelastic domain walls. The relative concentration of defects in walls, Nd, follows a power law distribution as a function of the total defect concentration C: N d ˜ C α with α = 0.4 . The enrichment Nd/C ranges from ˜50 times when C = 10 ppm to ˜3 times when C = 1000 ppm. The resulting enrichment is due to nucleation at defect sites as observed in large scale MD simulations. The dynamics of domain nucleation and switching is dependent on the defect concentration. Their energy distribution follows the power law with exponents during yield between ɛ ˜ 1.82 and 2.0 when the defect concentration increases. The power law exponent is ɛ ≈ 2.7 in the plastic regime, independent of the defect concentration.

Exploring the genetics underlying autoimmune diseases with network analysis and link prediction

KAUST Repository

Alanis Lobato, Gregorio; Cannistraci, Carlo; Ravasi, Timothy

2014-01-01

Ever since the first Genome Wide Association Study (GWAS) was carried out we have seen an important number of discoveries of biological and clinical relevance. However, there are some scientists that consider that these research outcomes and their utility are far from what was expected from this experimental design. We instead believe that the thousands of genetic variants associated with complex disorders by means of GWASs are an extremely valuable source of information that needs to be mined in a different way. Based on this philosophy, we followed a holistic perspective to analyze GWAS data and explored the structural properties of the network representation of one of these datasets with the aim to advance our understanding of the genetic intricacies underlying autoimmune human diseases. The simplicity, computational efficiency and precision of the tools proposed in this paper represent a new means to address GWAS data and contribute to the better exploitation of these rich sources of information. © 2014 IEEE.

Exploring the genetics underlying autoimmune diseases with network analysis and link prediction

KAUST Repository

Alanis Lobato, Gregorio

2014-02-01

Ever since the first Genome Wide Association Study (GWAS) was carried out we have seen an important number of discoveries of biological and clinical relevance. However, there are some scientists that consider that these research outcomes and their utility are far from what was expected from this experimental design. We instead believe that the thousands of genetic variants associated with complex disorders by means of GWASs are an extremely valuable source of information that needs to be mined in a different way. Based on this philosophy, we followed a holistic perspective to analyze GWAS data and explored the structural properties of the network representation of one of these datasets with the aim to advance our understanding of the genetic intricacies underlying autoimmune human diseases. The simplicity, computational efficiency and precision of the tools proposed in this paper represent a new means to address GWAS data and contribute to the better exploitation of these rich sources of information. © 2014 IEEE.

Using Bayesian Models to Assess the Effects of Under-reporting of Cannabis Use on the Association with Birth Defects, National Birth Defects Prevention Study, 1997–2005

Science.gov (United States)

van Gelder, Marleen M. H. J.; Rogier, A.; Donders, T.; Devine, Owen; Roeleveld, Nel; Reefhuis, Jennita

2015-01-01

Background Studies on associations between periconceptional cannabis exposure and birth defects have mainly relied on self-reported exposure. Therefore, the results may be biased due to underreporting of the exposure. The aim of this study was to quantify the potential effects of this form of exposure misclassification. Methods Using multivariable logistic regression, we re-analyzed associations between periconceptional cannabis use and 20 specific birth defects using data from the National Birth Defects Prevention Study from 1997–2005 for 13 859 case infants and 6556 control infants. For seven birth defects, we implemented four Bayesian models based on various assumptions concerning the sensitivity of self-reported cannabis use to estimate odds ratios (ORs), adjusted for confounding and underreporting of the exposure. We used information on sensitivity of self-reported cannabis use from the literature for prior assumptions. Results The results unadjusted for underreporting of the exposure showed an association between cannabis use and anencephaly (posterior OR 1.9 [95% credible interval (CRI) 1.1, 3.2]) which persisted after adjustment for potential exposure misclassification. Initially, no statistically significant associations were observed between cannabis use and the other birth defect categories studied. Although adjustment for underreporting did not notably change these effect estimates, cannabis use was associated with esophageal atresia (posterior OR 1.7 [95% CRI 1.0, 2.9]), diaphragmatic hernia (posterior OR 1.8 [95% CRI 1.1, 3.0]) and gastroschisis (posterior OR 1.7 [95% CRI 1.2, 2.3]) after correction for exposure misclassification. Conclusions Underreporting of the exposure may have obscured some cannabis-birth defect associations in previous studies. However, the resulting bias is likely to be limited. PMID:25155701

Low-temperature annealing of radiation defects in electron-irradiated gallium phosphide

International Nuclear Information System (INIS)

Kolb, A.A.; Megela, I.G.; Buturlakin, A.P.; Goyer, D.B.

1990-01-01

The isochronal annealing of radiation defects in high-energy electron irradiated n-GaP monocrystals within the 77 to 300 K range has been investigated by optical and electrical techniques. The changes in conductance and charge carrier mobility as functions of annealing temperature as well as the variation of optical absorption spectra of GaP under irradiation and annealing provide evidence that most of radiation defects are likely secondary complexes of defects

Actinic inspection of multilayer defects on EUV masks

International Nuclear Information System (INIS)

Barty, A; Liu, Y; Gullikson, E; Taylor, J S; Wood, O

2005-01-01

The production of defect-free mask blanks, and the development of techniques for inspecting and qualifying EUV mask blanks, remains a key challenge for EUV lithography. In order to ensure a reliable supply of defect-free mask blanks, it is necessary to develop techniques to reliably and accurately detect defects on un-patterned mask blanks. These inspection tools must be able to accurately detect all critical defects whilst simultaneously having the minimum possible false-positive detection rate. There continues to be improvement in high-speed non-actinic mask blank inspection tools, and it is anticipated that these tools can and will be used by industry to qualify EUV mask blanks. However, the outstanding question remains one of validating that non-actinic inspection techniques are capable of detecting all printable EUV defects. To qualify the performance of non-actinic inspection tools, a unique dual-mode EUV mask inspection system has been installed at the Advanced Light Source (ALS) synchrotron at Lawrence Berkeley National Laboratory. In high-speed inspection mode, whole mask blanks are scanned for defects using 13.5-nm wavelength light to identify and map all locations on the mask that scatter a significant amount of EUV light. In imaging, or defect review mode, a zone plate is placed in the reflected beam path to image a region of interest onto a CCD detector with an effective resolution on the mask of 100-nm or better. Combining the capabilities of the two inspection tools into one system provides the unique capability to determine the coordinates of native defects that can be used to compare actinic defect inspection with visible light defect inspection tools under commercial development, and to provide data for comparing scattering models for EUV mask defects

Intraspecific Genetic dynamics under Climate Change

DEFF Research Database (Denmark)

Florez Rodriguez, Alexander

Climate change has a deep influence on the maintenance and generation of global biodiversity. Past contractions, expansions and shifts in species’ ranges drove to changes in species genetic diversity. Noteworthy, the interaction among: climate change, range, population size and extinction is often...

Screening for GPR101 defects in pediatric pituitary corticotropinomas.

OpenAIRE

Trivellin, Giampaolo(*); Correa, Ricardo R.(*); Batsis, Maria; Faucz, Fabio R.; Chittiboina, Prashant; Bjelobaba, Ivana; Larco, Darwin O.; Quezado, Martha; Daly, Adrian; Stojilkovic, Stanko S.; Wu, T. John; Beckers, Albert; Lodish, Maya; Stratakis, Constantine A.

2016-01-01

Cushing disease (CD) in children is caused by adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas. Germline or somatic mutations in genes such as MEN1, CDKIs, AIP, and USP8 have been identified in pediatric CD, but the genetic defects in a significant percentage of cases are still unknown. We investigated the orphan G protein-coupled receptor GPR101, a gene known to be involved in somatotropinomas, for its possible involvement in corticotropinomas. We performed GPR101 sequencing, ...

Length-scale and strain rate-dependent mechanism of defect formation and fracture in carbon nanotubes under tensile loading

Energy Technology Data Exchange (ETDEWEB)

Javvaji, Brahmanandam [Indian Institute of Science, Department of Aerospace Engineering (India); Raha, S. [Indian Institute of Science, Department of Computational and Data Sciences (India); Mahapatra, D. Roy, E-mail: droymahapatra@aero.iisc.ernet.in [Indian Institute of Science, Department of Aerospace Engineering (India)

2017-02-15

Electromagnetic and thermo-mechanical forces play a major role in nanotube-based materials and devices. Under high-energy electron transport or high current densities, carbon nanotubes fail via sequential fracture. The failure sequence is governed by certain length scale and flow of current. We report a unified phenomenological model derived from molecular dynamic simulation data, which successfully captures the important physics of the complex failure process. Length-scale and strain rate-dependent defect nucleation, growth, and fracture in single-walled carbon nanotubes with diameters in the range of 0.47 to 2.03 nm and length which is about 6.17 to 26.45 nm are simulated. Nanotubes with long length and small diameter show brittle fracture, while those with short length and large diameter show transition from ductile to brittle fracture. In short nanotubes with small diameters, we observe several structural transitions like Stone-Wales defect initiation, its propagation to larger void nucleation, formation of multiple chains of atoms, conversion to monatomic chain of atoms, and finally complete fracture of the carbon nanotube. Hybridization state of carbon-carbon bonds near the end cap evolves, leading to the formation of monatomic chain in short nanotubes with small diameter. Transition from ductile to brittle fracture is also observed when strain rate exceeds a critical value. A generalized analytical model of failure is established, which correlates the defect energy during the formation of atomic chain with aspect ratio of the nanotube and strain rate. Variation in the mechanical properties such as elastic modulus, tensile strength, and fracture strain with the size and strain rate shows important implications in mitigating force fields and ways to enhance the life of electronic devices and nanomaterial conversion via fracture in manufacturing.

Failure of RNA synthesis to recover after UV irradiation: an early defect in cells from individuals with Cockayne's syndrome and xeroderma pigmentosum

International Nuclear Information System (INIS)

Mayne, L.V.; Lehmann, A.R.

1982-01-01

Previous work has shown that in cells from the ultraviolet-sensitive genetic disorder, Cockayne's syndrome, DNA synthesis fails to recover after ultraviolet irradiation, despite the fact that these cells have no detectable defect in either excision or daughter-strand repair pathways. We now show that Cockayne cells, as well as cells from a number of patients with xeroderma pigmentosum, are sensitive to the lethal effects of UV irradiation in stationary phase under conditions in which no DNA is synthesized after irradiation. Furthermore, in normal and defective human fibroblasts, RNA synthesis is depressed after UV irradiation. In normal (dividing) cells, RNA synthesis recovers very rapidly, but this recovery does not occur in Cockayne cells, and it is reduced or absent in xeroderma pigmentosum cells from different complementation groups. Qualitatively, similar results are obtained with cells in stationary phase. The recovery of RNA synthesis in the various defective cell strains is not correlated with the overall extent of excision repair, but there is some correlation between recovery of RNA synthesis and cell survival after ultraviolet irradiation. These results implicate recovery of RNA synthesis as an important early response to ultraviolet irradiation

p38 MAPK-Mediated Bmi-1 Down-Regulation and Defective Proliferation in ATM-Deficient Neural Stem Cells Can Be Restored by Akt Activation

Science.gov (United States)

Kim, Jeesun; Hwangbo, Jeon; Wong, Paul K. Y.

2011-01-01

A-T (ataxia telangiectasia) is a genetic disease caused by a mutation in the Atm (A-T mutated) gene that leads to neurodegeneration. Despite an increase in the numbers of studies in this area in recent years, the mechanisms underlying neurodegeneration in human A-T are still poorly understood. Previous studies demonstrated that neural stem cells (NSCs) isolated from the subventricular zone (SVZ) of Atm -/- mouse brains show defective self-renewal and proliferation, which is accompanied by activation of chronic p38 mitogen-activated protein kinase (MAPK) and a lower level of the polycomb protein Bmi-1. However, the mechanism underlying Bmi-1 down-regulation and its relevance to defective proliferation in Atm-/- NSCs remained unclear. Here, we show that over-expression of Bmi-1 increases self-renewal and proliferation of Atm-/- NSCs to normal, indicating that defective proliferation in Atm-/- NSCs is a consequence of down-regulation of Bmi-1. We also demonstrate that epidermal growth factor (EGF)-induced Akt phosphorylation renders Bmi-1 resistant to the proteasomal degradation, leading to its stabilization and accumulation in the nucleus. However, inhibition of the Akt-dependent Bmi-1 stabilizing process by p38 MAPK signaling reduces the levels of Bmi-1. Treatment of the Atm-/- NSCs with a specific p38 MAPK inhibitor SB203580 extended Bmi-1 posttranscriptional turnover and H2A ubiquitination in Atm-/- NSCs. Our observations demonstrate the molecular basis underlying the impairment of self-renewal and proliferation in Atm-/- NSCs through the p38 MAPK-Akt-Bmi-1-p21 signaling pathway. PMID:21305053

Identification of the DNA repair defects in a case of Dubowitz syndrome.

Directory of Open Access Journals (Sweden)

Jingyin Yue

Full Text Available Dubowitz Syndrome is an autosomal recessive disorder with a unique set of clinical features including microcephaly and susceptibility to tumor formation. Although more than 140 cases of Dubowitz syndrome have been reported since 1965, the genetic defects of this disease has not been identified. In this study, we systematically analyzed the DNA damage response and repair capability of fibroblasts established from a Dubowitz Syndrome patient. Dubowitz syndrome fibroblasts are hypersensitive to ionizing radiation, bleomycin, and doxorubicin. However, they have relatively normal sensitivities to mitomycin-C, cisplatin, and camptothecin. Dubowitz syndrome fibroblasts also have normal DNA damage signaling and cell cycle checkpoint activations after DNA damage. These data implicate a defect in repair of DNA double strand break (DSB likely due to defective non-homologous end joining (NHEJ. We further sequenced several genes involved in NHEJ, and identified a pair of novel compound mutations in the DNA Ligase IV gene. Furthermore, expression of wild type DNA ligase IV completely complement the DNA repair defects in Dubowitz syndrome fibroblasts, suggesting that the DNA ligase IV mutation is solely responsible for the DNA repair defects. These data suggests that at least subset of Dubowitz syndrome can be attributed to DNA ligase IV mutations.

How powerful are summary-based methods for identifying expression-trait associations under different genetic architectures?

Science.gov (United States)

Veturi, Yogasudha; Ritchie, Marylyn D

2018-01-01

Transcriptome-wide association studies (TWAS) have recently been employed as an approach that can draw upon the advantages of genome-wide association studies (GWAS) and gene expression studies to identify genes associated with complex traits. Unlike standard GWAS, summary level data suffices for TWAS and offers improved statistical power. Two popular TWAS methods include either (a) imputing the cis genetic component of gene expression from smaller sized studies (using multi-SNP prediction or MP) into much larger effective sample sizes afforded by GWAS - TWAS-MP or (b) using summary-based Mendelian randomization - TWAS-SMR. Although these methods have been effective at detecting functional variants, it remains unclear how extensive variability in the genetic architecture of complex traits and diseases impacts TWAS results. Our goal was to investigate the different scenarios under which these methods yielded enough power to detect significant expression-trait associations. In this study, we conducted extensive simulations based on 6000 randomly chosen, unrelated Caucasian males from Geisinger's MyCode population to compare the power to detect cis expression-trait associations (within 500 kb of a gene) using the above-described approaches. To test TWAS across varying genetic backgrounds we simulated gene expression and phenotype using different quantitative trait loci per gene and cis-expression /trait heritability under genetic models that differentiate the effect of causality from that of pleiotropy. For each gene, on a training set ranging from 100 to 1000 individuals, we either (a) estimated regression coefficients with gene expression as the response using five different methods: LASSO, elastic net, Bayesian LASSO, Bayesian spike-slab, and Bayesian ridge regression or (b) performed eQTL analysis. We then sampled with replacement 50,000, 150,000, and 300,000 individuals respectively from the testing set of the remaining 5000 individuals and conducted GWAS on each

Heterogeneous rates for birth defects in Latin America: hints on causality.

Science.gov (United States)

Lopez-Camelo, J S; Orioli, I M

1996-01-01

The aim of this work was to disclose risk factors associated with birth defects which were heterogeneously distributed in the different geographic regions sampled by the Latin American Collaborative Study of Congenital Malformations (ECLAMC). The material included 2,159,065 hospital births, delivered in the 1967-1989 period in 24 geographic regions of Latin America. Birth defect types with 50 case-control pairs or more were analyzed. A risk factor was defined as that available variable with differential geographic rates, correlated with those of a given birth defect type. Identified factors were tested by case-control multivariate logistic regression to confirm their role in the occurrence of the defect. Altitude and maternal acute illness during first trimester of pregnancy, named influenza, were risk factors for microtia. Prenatal drug exposure, mainly sex hormones, were connected with the occurrence of hypospadias in low frequency areas, while Native ancestry was a "protective" factor in the same regions. Acute (influenza), and chronic (epilepsy and syphilis) maternal illness during first trimester of pregnancy and gravidity higher than four were risk factors for cleft lip. The independence of these variables from maternal age suggested that low maternal socioeconomic level could explain the high birth defect order and, perhaps, syphilis in mothers. Postaxial polydactyly was associated with parental consanguinity, as well as Afro-American ancestry, suggesting genetic heterogeneity.

The Prevalence of Enamel Defects in Students 7-12 Years of Age in Isfahan

Directory of Open Access Journals (Sweden)

Mahmodian J

2000-05-01

Full Text Available Dental enamel is the end product of amelogenesis, which can be considered to take place in"nthree interrelated phases. When this complex sequence of cytological and physicochemica! events"ndisrupted by genetic or environmental factors, the function of the ameloblasts may be disrupted"npermanently or temporarily. The result shows qualitative and quantitative defects that may range from a"ncomplete absence of enamel or a slight discoloration. The aim of this study was to determine the"nprevalence of enamel defects by DDE index in a randomly selection group of 1637 students age 7-12"nyears old in Isfahan (0.2-0.3 PPMF". Enamel defects were present on one or more teeth in 27% of the"ncases. The most common affected tooth was the central maxillary and then first molar of maxilla. The"nmost common affected surfaces were buccal. Hypoplastic defects were found in first molar; however"npremolar and canine were affected by diffuse white lines opacity.

Studies of defects and defect agglomerates by positron annihilation spectroscopy

DEFF Research Database (Denmark)

Eldrup, Morten Mostgaard; Singh, B.N.

1997-01-01

A brief introduction to positron annihilation spectroscopy (PAS), and in particular lo its use for defect studies in metals is given. Positrons injected into a metal may become trapped in defects such as vacancies, vacancy clusters, voids, bubbles and dislocations and subsequently annihilate from...... the trapped state iri the defect. The annihilation characteristics (e.g., the lifetime of the positron) can be measured and provide information about the nature of the defect (e.g., size, density, morphology). The technique is sensitive to both defect size (in the range from monovacancies up to cavities...

Bayesian inference on genetic merit under uncertain paternity

Directory of Open Access Journals (Sweden)

Tempelman Robert J

2003-09-01

Full Text Available Abstract A hierarchical animal model was developed for inference on genetic merit of livestock with uncertain paternity. Fully conditional posterior distributions for fixed and genetic effects, variance components, sire assignments and their probabilities are derived to facilitate a Bayesian inference strategy using MCMC methods. We compared this model to a model based on the Henderson average numerator relationship (ANRM in a simulation study with 10 replicated datasets generated for each of two traits. Trait 1 had a medium heritability (h2 for each of direct and maternal genetic effects whereas Trait 2 had a high h2 attributable only to direct effects. The average posterior probabilities inferred on the true sire were between 1 and 10% larger than the corresponding priors (the inverse of the number of candidate sires in a mating pasture for Trait 1 and between 4 and 13% larger than the corresponding priors for Trait 2. The predicted additive and maternal genetic effects were very similar using both models; however, model choice criteria (Pseudo Bayes Factor and Deviance Information Criterion decisively favored the proposed hierarchical model over the ANRM model.

Alloys under irradiation

International Nuclear Information System (INIS)

Martin, G.; Bellon, P.; Soisson, F.

1997-01-01

During the last two decades, some effort has been devoted to establishing a phenomenology for alloys under irradiation. Theoretically, the effects of the defect supersaturation, sustained defect fluxes and ballistic mixing on solid solubility under irradiation can now be formulated in a unified manner, at least for the most simple cases: coherent phase transformations and nearest-neighbor ballistic jumps. Even under such restrictive conditions, several intriguing features documented experimentally can be rationalized, sometimes in a quantitative manner and simple qualitative rules for alloy stability as a function of irradiation conditions can be formulated. A quasi-thermodynamic formalism can be proposed for alloys under irradiation. However, this point of view has limits illustrated by recent computer simulations. (orig.)

Genetic Mutations, Birth Lengths, Weights and Head Circumferences of Children with IGF-I Receptor Defects. Comparison with other Congenital Defects in the GH/IGF-I axis.

Science.gov (United States)

Essakow, Jenna Lee; Lauterpacht, Aharon; Lilos, Pearl; Kauli, Rivka; Laron, Zvi

2016-09-01

In recent years more and more genetic defects along the GHRH-GH-IGF-I axis have been reported. Mutations of the IGF-I receptor (R) are a rare abnormality of whom only the heterozygote progenies survive. To summarize, from the literature, data on birth length, weight and head circumference of neonates with IGF-I-R mutations, and to correlate the data with that of other types of mutations in the GH/IGF-I axis. Sixty seven neonates from 24 published articles were included and forty seven different mutations of the IGF-I (R) located on chromosome 15 have been identified. Mean (±SD) birth length (BL), available for 26, (10 M, 16F) neonates with a gestational age of 34-41weeks, was 44.2±4cm; one was premature (30cm at 31 weeks). There was a significant correlation between birth length and gestational age (GA) r=0.71 (p>.001). Mean birth weight (BW) of 41 neonates (18M, 23F) was 2388±743gr. Two premature neonates weighed 650gr and 950gr respectively. The BW correlated significantly with gestational age, (males: r=0.68; p=0.007, females: r=0.49; p=0.024). The BMI of 25 neonates ranged from 6 to 13. In 22 records marked microcephaly was ascertained or stated. Nine of 16 mothers were short (133 -148cm), m±SD = 150.5±7.3cm. Copyright© of YS Medical Media ltd.

Phase instability in crystals under irradiation

International Nuclear Information System (INIS)

Martin, G.

1975-01-01

A diffusion term is introduced in the standard chemical rate model of the defect population in crystals under irradiation. For point defect generation rates larger than a critical value (g*), the uniform point defect population is shown to be unstable with respect to spatial fluctuations of the point defect concentration. g* is temperature dependent. Severala effects including the nucleation of arrays of point defect clusters, or radiation induced precipitation may occur above the instability threshold. Defect-defect interaction potentials play a crucial role in the numerical value of this threshold [fr

Identification of additional genes under the control of the transcription factor sigma F of Bacillus subtilis.

OpenAIRE

Decatur, A; Losick, R

1996-01-01

We describe the identification of five transcriptional units under the control of the sporulation transcription factor sigma F in Bacillus subtilis. These are csfA, csfB, csfC, csfD, and csfF, located at approximately 230 degrees, 2 degrees, 316 degrees, 205 degrees, and approximately 290 degrees, respectively, on the genetic map. Null mutations in csfA, csfB, csfC, or csfD, either alone or together, do not cause a noticeable defect in sporulation or germination.

Defect modelling

International Nuclear Information System (INIS)

Norgett, M.J.

1980-01-01

Calculations, drawing principally on developments at AERE Harwell, of the relaxation about lattice defects are reviewed with emphasis on the techniques required for such calculations. The principles of defect modelling are outlined and various programs developed for defect simulations are discussed. Particular calculations for metals, ionic crystals and oxides, are considered. (UK)

Interatomic potentials and the simulation of lattice defects in metals

International Nuclear Information System (INIS)

Heugten, W.F.W.M. van.

1979-01-01

The computer simulation technique is applied to investigate the properties of point defects and line defects in metals. For that purpose crystallites are constructed in which these defects are simulated. In the case of line defects (dislocations) the initial positions of the atoms, surrounding the dislocations, are determined using the elastic theory of anisotropic media. Hereafter the atoms in such crystallites are allowed to relax to there minimum potential energy positions under the influence of the interatomic forces. These forces are derived from interatomic interaction potentials. These potentials are together with the boundary conditions of the simulated crystallite the main input data in these computer simulation models. The metals considered include molybdenum, tungsten and tantalum. (Auth.)

Study on surface defects in milling Inconel 718 super alloy

Energy Technology Data Exchange (ETDEWEB)

Chang, Liu; Chengzu, Ren; Guofeng, Wang; Yinwei, Yang; Lu, Zhang [Tianjin University, Tianjin (China)

2015-04-15

Nickel-based alloys have been extensively used as critical components in aerospace industry, especially in the key section of aero engine. In general, these sections are manufactured by milling process because most of them have complex forms. However, surface defects appear frequently in milling due to periodic impact force, which leads to the deterioration of the fatigue life. We conducted milling experiments under different cutting conditions and found that four kinds of defects, i.e., tear, cavity, build up edge (BUE) and groove, commonly appear on the machined surface. Based on the observed results, the morphology and generation regime of these defects are analyzed and the carbide particle cracking is discussed to explain the appearance of the nickel alloy defects. To study the effect of the cutting parameters on the severity of these surface defects, two qualitative indicators, which are named as average number of the defects per field and average area ratio of the defects per field, are presented and the influence laws are summarized based on the results correspondingly. This study is helpful for understanding the generation mechanism of the surface defects during milling process of nickel based super alloy.

Neural tube defects in Waardenburg syndrome: A case report and review of the literature.

Science.gov (United States)

Hart, Joseph; Miriyala, Kalpana

2017-09-01

Waardenburg syndrome type 1 (WS1) is an autosomal dominant genetic condition characterized by sensorineural deafness and pigment abnormalities, and is caused by variants in the PAX3 homeodomain. PAX3 variants have been associated with severe neural tube defects in mice and humans, but the frequency and clinical manifestations of this symptom remain largely unexplored in humans. Consequently, the role of PAX3 in human neural tube formation remains a study of interest, for clinical as well as research purposes. Though the association between spina bifida and WS1 is now well-documented, no study has attempted to characterize the range of spina bifida phenotypes seen in WS. Spina bifida encompasses several diagnoses with a wide scope of clinical severity, ranging from spina bifida occulta to myelomeningocele. We present a patient with Waardenburg syndrome type 1 caused by a novel missense variant in PAX3, presenting with myelomeningocele, Arnold-Chiari malformation, and hydrocephalus at birth. Additionally, we review 32 total cases of neural tube defects associated with WS. Including this report, there have been 15 published cases of myelomeningocele, 10 cases of unspecified spina bifida, 3 cases of sacral dimples, 0 cases of meningocele, and 4 cases of miscellaneous other neural tube defects. Though the true frequency of each phenotype cannot be determined from this collection of cases, these results demonstrate that Waardenburg syndrome type 1 carries a notable risk of severe neural tube defects, which has implications in prenatal and genetic counseling. © 2017 Wiley Periodicals, Inc.

High temperature defect equilibrium in ZnS:Cu single crystals

Energy Technology Data Exchange (ETDEWEB)

Lott, K.; Shinkarenko, S.; Tuern, L.; Nirk, T.; Oepik, A. [Department of Materials Science, Tallinn University of Technology, Tallinn (Estonia); Kallavus, U. [Centre for Materials Research, Tallinn University of Technology, Tallinn (Estonia); Gorokhova, E. [Scientific Research and Technological Institute of Optical Material Science, S. I. Vavilov State Optical Institute, All-Russia Science Center, St. Petersburg (Russian Federation); Grebennik, A.; Vishnjakov, A. [Department of Physical Chemistry, D. Mendelejev University of Chemical Technology of Russia, Moscow (Russian Federation)

2010-07-15

High temperature investigations in ZnS:Cu crystals were performed under defined conditions. High temperature electrical conductivity and copper solubility data were obtained under different component vapour pressures and under different sample temperatures. The experimental data at sulphur vapour pressure can be explained by the inclusion of abnormal site occupation i.e. by antistructural disorder. Compensating association of copper with this antistructure defect may occur. Antistructure disorder disappears with increasing of zinc vapour pressure and with increasing role of holes in bipolar conductivity. The method for solving the system of quasichemical reactions without approximation was used to model high temperature defect equilibrium. This model contains antistructure disorder and copper solubility limitation. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

The reverse sural artery fasciomusculocutaneous flap for small lower-limb defects: the use of the gastrocnemius muscle cuff as a plug for small bony defects following debridement of infected/necrotic bone.

Science.gov (United States)

Al-Qattan, M M

2007-09-01

The reverse sural artery fasciomusculocutaneous flap is a modification of the original fasciocutaneous flap in which a midline gastrocnemius muscle cuff around the buried sural pedicle is included in the flap. This modification was done to improve the blood supply of the distal part of the flap, which is harvested from the upper leg. The aim of this paper is to demonstrate that there is another important advantage of the modified flap: the use of the muscle cuff as a "plug" for small lower limb defects following debridement of infected/necrotic bone. A total of 10 male adult patients with small complex lower-limb defects with underlying bone pathology were treated with the modified flap using the muscle component to fill up the small bony defects. The bony pathology included necrotic exposed bone without evidence of osteomyelitis or wound infection (n = 1), an underlying neglected tibial fracture with wound infection (n = 4), and a sinus at the heel with underlying calcaneal osteomyelitis (n = 5). Primary wound healing of the flap into the defect was noted in all patients. No recurrence of calcaneal osteomyelitis was seen and all tibial fractures united following appropriate orthopedic fixation. It was concluded that the reverse sural artery fasciomusculocutaneous flap is well suited for small complex lower-limb defects with underlying bone pathology.

A Nondominated Genetic Algorithm Procedure for Multiobjective Discrete Network Design under Demand Uncertainty

Directory of Open Access Journals (Sweden)

Bian Changzhi

2015-01-01

Full Text Available This paper addresses the multiobjective discrete network design problem under demand uncertainty. The OD travel demands are supposed to be random variables with the given probability distribution. The problem is formulated as a bilevel stochastic optimization model where the decision maker’s objective is to minimize the construction cost, the expectation, and the standard deviation of total travel time simultaneously and the user’s route choice is described using user equilibrium model on the improved network under all scenarios of uncertain demand. The proposed model generates globally near-optimal Pareto solutions for network configurations based on the Monte Carlo simulation and nondominated sorting genetic algorithms II. Numerical experiments implemented on Nguyen-Dupuis test network show trade-offs among construction cost, the expectation, and standard deviation of total travel time under uncertainty are obvious. Investment on transportation facilities is an efficient method to improve the network performance and reduce risk under demand uncertainty, but it has an obvious marginal decreasing effect.

[Genetics of congenital heart diseases].

Science.gov (United States)

Bonnet, Damien

2017-06-01

Developmental genetics of congenital heart diseases has evolved from analysis of serial slices in embryos towards molecular genetics of cardiac morphogenesis with a dynamic view of cardiac development. Genetics of congenital heart diseases has also changed from formal genetic analysis of familial recurrences or population-based analysis to screening for mutations in candidates genes identified in animal models. Close cooperation between molecular embryologists, pathologists involved in heart development and pediatric cardiologists is crucial for further increase of knowledge in the field of cardiac morphogenesis and genetics of cardiac defects. The genetic model for congenital heart disease has to be revised to favor a polygenic origin rather than a monogenic one. The main mechanism is altered genic dosage that can account for heart diseases in chromosomal anomalies as well as in point mutations in syndromic and isolated congenital heart diseases. The use of big data grouping information from cardiac development, interactions between genes and proteins, epigenetic factors such as chromatin remodeling or DNA methylation is the current source for improving our knowledge in the field and to give clues for future therapies. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Defect phase diagram for doping of Ga2O3

OpenAIRE

Stephan Lany

2018-01-01

For the case of n-type doping of β-Ga2O3 by group 14 dopants (C, Si, Ge, Sn), a defect phase diagram is constructed from defect equilibria calculated over a range of temperatures (T), O partial pressures (pO2), and dopant concentrations. The underlying defect levels and formation energies are determined from first-principles supercell calculations with GW bandgap corrections. Only Si is found to be a truly shallow donor, C is a deep DX-like (lattice relaxed donor) center, and Ge and Sn have d...

Non-destructive Testing of Wood Defects Based on Discriminant Analysis Method

Directory of Open Access Journals (Sweden)

Wenshu LIN

2015-09-01

Full Text Available The defects of wood samples were tested by the technique of stress wave and ultrasonic technology, and the testing results were comparatively analyzed by using the Fisher discriminant analysis in the statistic software of SPSS. The differences of defect detection sensitivity and accuracy for stress wave and ultrasonic under different wood properties and defects were concluded. Therefore, in practical applications, according to different situations the corresponding wood non- destructive testing method should be used, or the two detection methods are applied at the same time in order to compensate for its shortcomings with each other to improve the ability to distinguish the timber defects. The results can provide a reference for further improvement of the reliability of timber defects detection.

Pipeline defect prediction using long range ultrasonic testing and intelligent processing

International Nuclear Information System (INIS)

Dino Isa; Rajprasad Rajkumar

2009-01-01

This paper deals with efforts to improve nondestructive testing (NDT) techniques by using artificial intelligence in detecting and predicting pipeline defects such as cracks and wall thinning. The main emphasis here will be on the prediction of corrosion type defects rather than just detection after the fact. Long range ultrasonic testing will be employed, where a ring of piezoelectric transducers are used to generate torsional guided waves. Various defects such as cracks as well as corrosion under insulation (CUI) will be simulated on a test pipe. The machine learning algorithm known as the Support Vector Machine (SVM) will be used to predict and classify transducer signals using regression and large margin classification. Regression results show that the SVM is able to accurately predict future defects based on trends of previous defect. The classification performance was also exceptional showing a facility to detect defects at different depths as well as for distinguishing closely spaced defects. (author)

Estimating the risks of cancer mortality and genetic defects resulting from exposures to low levels of ionizing radiation

International Nuclear Information System (INIS)

Buhl, T.E.; Hansen, W.R.

1984-05-01

Estimators for calculating the risk of cancer and genetic disorders induced by exposure to ionizing radiation have been recommended by the US National Academy of Sciences Committee on the Biological Effects of Ionizing Radiations, the UN Scientific Committee on the Effects of Atomic Radiation, and the International Committee on Radiological Protection. These groups have also considered the risks of somatic effects other than cancer. The US National Council on Radiation Protection and Measurements has discussed risk estimate procedures for radiation-induced health effects. The recommendations of these national and international advisory committees are summarized and compared in this report. Based on this review, two procedures for risk estimation are presented for use in radiological assessments performed by the US Department of Energy under the National Environmental Policy Act of 1969 (NEPA). In the first procedure, age- and sex-averaged risk estimators calculated with US average demographic statistics would be used with estimates of radiation dose to calculate the projected risk of cancer and genetic disorders that would result from the operation being reviewed under NEPA. If more site-specific risk estimators are needed, and the demographic information is available, a second procedure is described that would involve direct calculation of the risk estimators using recommended risk-rate factors. The computer program REPCAL has been written to perform this calculation and is described in this report. 25 references, 16 tables

Estimating the risks of cancer mortality and genetic defects resulting from exposures to low levels of ionizing radiation

Energy Technology Data Exchange (ETDEWEB)

Buhl, T.E.; Hansen, W.R.

1984-05-01

Estimators for calculating the risk of cancer and genetic disorders induced by exposure to ionizing radiation have been recommended by the US National Academy of Sciences Committee on the Biological Effects of Ionizing Radiations, the UN Scientific Committee on the Effects of Atomic Radiation, and the International Committee on Radiological Protection. These groups have also considered the risks of somatic effects other than cancer. The US National Council on Radiation Protection and Measurements has discussed risk estimate procedures for radiation-induced health effects. The recommendations of these national and international advisory committees are summarized and compared in this report. Based on this review, two procedures for risk estimation are presented for use in radiological assessments performed by the US Department of Energy under the National Environmental Policy Act of 1969 (NEPA). In the first procedure, age- and sex-averaged risk estimators calculated with US average demographic statistics would be used with estimates of radiation dose to calculate the projected risk of cancer and genetic disorders that would result from the operation being reviewed under NEPA. If more site-specific risk estimators are needed, and the demographic information is available, a second procedure is described that would involve direct calculation of the risk estimators using recommended risk-rate factors. The computer program REPCAL has been written to perform this calculation and is described in this report. 25 references, 16 tables.

Somatic cell and molecular genetics approach to DNA repair and mutagenesis

International Nuclear Information System (INIS)

Thompson, L.H.

1985-01-01

In the CHO cell line, UV-sensitive mutants representing five genetic complementation groups have been identified. Mutants from each of these groups were shown to be defective in performing the incision step of repair after exposure to UV. The large number of complementation groups of xeroderma pigmentosa mutations has raised the question whether these groups all correspond to single gene loci. The same issue applies to the 5 groups of UV-sensitive CHO mutants. One approach toward answering this question is to localize in the human karyotype the genes that complement the defects in the CHO mutants. Thus, by making CHO/human cell hybrids under the appropriate selective conditions, we have begun to map each of the complementing human genes. The mutation in strain UV20 (Group 2) was complemented by human chromosome 19. Preliminary evidence suggests that UV5 may also be complemented by human chromosome 19 while each of the other 3 groups involves a different human chromosome. Somewhat surprisingly, mutant EM9 is also complemented by a gene on chromosome 19

Syndromes, Disorders and Maternal Risk Factors Associated with Neural Tube Defects (II

Directory of Open Access Journals (Sweden)

Chih-Ping Chen

2008-03-01

Full Text Available Fetuses with neural tube defects (NTDs maybe associated with syndromes, disorders, and maternal risk factors. This article provides a comprehensive review of syndromes, disorders, and maternal risk factors associated with NTDs, such as Currarino syndrome, sacral defect with anterior meningocele, Jarcho-Levin syndrome (spondylo-costal dysostosis, lateral meningocele syndrome, neurofibromatosis type I, Marfan syndrome, and hyperthermia. The recurrence risk and the preventive effect of maternal folic acid intake in NTDs associated with syndromes, disorders, and maternal risk factors may be different from those of non-syndromic multifactorial NTDs. Perinatal identification of NTDs should alert one to the syndromes, disorders, and maternal risk factors associated with NTDs, and prompt a thorough etiologic investigation and genetic counseling.

Problems and solutions in the estimation of genetic risks from radiation and chemicals

International Nuclear Information System (INIS)

Russell, W.L.

1980-01-01

Extensive investigations with mice on the effects of various physical and biological factors, such as dose rate, sex and cell stage, on radiation-induced mutation have provided an evaluation of the genetics hazards of radiation in man. The mutational results obtained in both sexes with progressive lowering of the radiation dose rate have permitted estimation of the mutation frequency expected under the low-level radiation conditions of most human exposure. Supplementing the studies on mutation frequency are investigations on the phenotypic effects of mutations in mice, particularly anatomical disorders of the skeleton, which allow an estimation of the degree of human handicap associated with the occurrence of parallel defects in man. Estimation of the genetic risk from chemical mutagens is much more difficult, and the research is much less advanced. Results on transmitted mutations in mice indicate a poor correlation with mutation induction in non-mammalian organisms

Defect States Emerging from a Non-Hermitian Flatband of Photonic Zero Modes

Science.gov (United States)

Qi, Bingkun; Zhang, Lingxuan; Ge, Li

2018-03-01

We show the existence of a flatband consisting of photonic zero modes in a gain and loss modulated lattice system as a result of the underlying non-Hermitian particle-hole symmetry. This general finding explains the previous observation in parity-time symmetric systems where non-Hermitian particle-hole symmetry is hidden. We further discuss the defect states in these systems, whose emergence can be viewed as an unconventional alignment of a pseudospin under the influence of a complex-valued pseudomagnetic field. These defect states also behave as a chain with two types of links, one rigid in a unit cell and one soft between unit cells, as the defect states become increasingly localized with the gain and loss strength.

Discriminant Analysis of Defective and Non-Defective Field Pea (Pisum sativum L.) into Broad Market Grades Based on Digital Image Features.

Science.gov (United States)

McDonald, Linda S; Panozzo, Joseph F; Salisbury, Phillip A; Ford, Rebecca

2016-01-01

Field peas (Pisum sativum L.) are generally traded based on seed appearance, which subjectively defines broad market-grades. In this study, we developed an objective Linear Discriminant Analysis (LDA) model to classify market grades of field peas based on seed colour, shape and size traits extracted from digital images. Seeds were imaged in a high-throughput system consisting of a camera and laser positioned over a conveyor belt. Six colour intensity digital images were captured (under 405, 470, 530, 590, 660 and 850nm light) for each seed, and surface height was measured at each pixel by laser. Colour, shape and size traits were compiled across all seed in each sample to determine the median trait values. Defective and non-defective seed samples were used to calibrate and validate the model. Colour components were sufficient to correctly classify all non-defective seed samples into correct market grades. Defective samples required a combination of colour, shape and size traits to achieve 87% and 77% accuracy in market grade classification of calibration and validation sample-sets respectively. Following these results, we used the same colour, shape and size traits to develop an LDA model which correctly classified over 97% of all validation samples as defective or non-defective.

Genetics of reproductive isolation in the Drosophila simulans clade: complex epistasis underlying hybrid male sterility.

Science.gov (United States)

Cabot, E L; Davis, A W; Johnson, N A; Wu, C I

1994-05-01

We have analyzed the sterility associated with introgressions of the distal one-fourth of the X chromosome from either Drosophila mauritiana or Drosophila sechellia into the genome of Drosophila simulans using a series of visible and DNA markers. Because in Drosophila hybrids, male sterility is usually complete and is often tightly linked with each of several markers used in crosses, a simple genetic basis has generally been assumed. In our low resolution mapping experiment, we were not able to reject the null hypothesis that a single gene, introgressed from either D. mauritiana or D. sechellia, is the cause of male sterility. High resolution mapping, however, reveals a much more complex picture. At least three distinct factors from D. mauritiana, or two from D. sechellia, were identified that need to be jointly present to confer full sterility. Each individual factor by itself is relatively ineffective in causing sterility, or even a partial spermatogenic defect. Moreover, there appear to be more sterility factors on comparable introgressions from D. mauritiana than from D. sechellia. On the basis of these observations, we propose a model which suggests that multilocus weak allele interactions are a very common cause of reproductive incompatibility between closely related species. We also present theoretical argument and empirical evidence against extrapolating the results of within-species analysis to interpret the genetic basis of species differences. The implications of this model on the theories of evolution of species differences and the attempt to understand the mechanisms of hybrid sterility/inviability at the molecular level are discussed.

Novel splice-site and missense mutations in the ALDH1A3 gene underlying autosomal recessive anophthalmia/microphthalmia.

Science.gov (United States)

Semerci, C Nur; Kalay, Ersan; Yıldırım, Cem; Dinçer, Tuba; Olmez, Akgün; Toraman, Bayram; Koçyiğit, Ali; Bulgu, Yunus; Okur, Volkan; Satıroğlu-Tufan, Lale; Akarsu, Nurten A

2014-06-01

This study aimed to identify the underlying genetic defect responsible for anophthalmia/microphthalmia. In total, two Turkish families with a total of nine affected individuals were included in the study. Affymetrix 250 K single nucleotide polymorphism genotyping and homozygosity mapping were used to identify the localisation of the genetic defect in question. Coding region of the ALDH1A3 gene was screened via direct sequencing. cDNA samples were generated from primary fibroblast cell cultures for expression analysis. Reverse transcriptase PCR (RT-PCR) analysis was performed using direct sequencing of the obtained fragments. The causative genetic defect was mapped to chromosome 15q26.3. A homozygous G>A substitution (c.666G>A) at the last nucleotide of exon 6 in the ALDH1A3 gene was identified in the first family. Further cDNA sequencing of ALDH1A3 showed that the c.666G>A mutation caused skipping of exon 6, which predicted in-frame loss of 43 amino acids (p.Trp180_Glu222del). A novel missense c.1398C>A mutation in exon 12 of ALDH1A3 that causes the substitution of a conserved asparagine by lysine at amino acid position 466 (p.Asn466Lys) was observed in the second family. No extraocular findings-except for nevus flammeus in one affected individual and a variant of Dandy-Walker malformation in another affected individual-were observed. Autistic-like behaviour and mental retardation were observed in three cases. In conclusion, novel ALDH1A3 mutations identified in the present study confirm the pivotal role of ALDH1A3 in human eye development. Autistic features, previously reported as an associated finding, were considered to be the result of social deprivation and inadequate parenting during early infancy in the presented families. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Familial defective apolipoprotein B-100: low density lipoproteins with abnormal receptor binding

International Nuclear Information System (INIS)

Innerarity, T.L.; Weisgraber, K.H.; Arnold, K.S.; Mahley, R.W.; Krauss, R.M.; Vega, G.L.; Grundy, S.M.

1987-01-01

Previous in vivo turnover studies suggested that retarded clearance of low density lipoproteins (LDL) from the plasma of some hypercholesterolemic patients is due to LDL with defective receptor binding. The present study examined this postulate directly by receptor binding experiments. The LDL from a hypercholesterolemic patient (G.R.) displayed a reduced ability to bind to the LDL receptors on normal human fibroblasts. The G.R. LDL possessed 32% of normal receptor binding activity. Likewise, the G.R. LDL were much less effective than normal LDL in competing with 125 I-labeled normal LDL for cellular uptake and degradation and in stimulating intracellular cholesteryl ester synthesis. The defect in LDL binding appears to be due to a genetic abnormality of apolipoprotein B-100: two brothers of the proband possess LDL defective in receptor binding, whereas a third brother and the proband's son have normally binding LDL. Further, the defect in receptor binding does not appear to be associated wit an abnormal lipid composition or structure of the LDL. Normal and abnormal LDL subpopulations were partially separated from plasma of two subjects by density-gradient ultracentrifugation, a finding consistent with the presence of a normal and a mutant allele. The affected family members appear to be heterozygous for this disorder, which has been designated familial defective apolipoprotein B-100. These studies indicate that the defective receptor binding results in inefficient clearance of LDL and the hypercholesterolemia observed in these patients

Reduction in Defect Content of ODS Alloys

Energy Technology Data Exchange (ETDEWEB)

Ritherdon, J

2001-05-15

The work detailed within this report is a continuation of earlier work carried out under contract number 1DX-SY382V. The earlier work comprises a literature review of the sources and types of defects found principally in Fe-based ODS alloys as well as experimental work designed to identify defects in the prototype ODS-Fe{sub 3}Al alloy, deduce their origins and to recommend methods of defect reduction. The present work is an extension of the experimental work already reported and concentrates on means of reduction of defects already identified rather than the search for new defect types. This report also includes results gathered during powder separation trials, conducted by the University of Groningen, Netherlands and coordinated by the University of Liverpool, involving the separation of different metallic powders in terms of their differing densities. The scope and objectives of the present work were laid out in the technical proposal ''Reduction in Defect Content in ODS Alloys-III''. All the work proposed in the ''Statement of Work'' section of the technical proposal has been carried out and all work extra to the ''Statement of Work'' falls within the context of an ODS-Fe{sub 3}Al alloy of improved overall quality and potential creep performance in the consolidated form. The outturn of the experimental work performed is reported in the following sections.

Description of data sources on defects of the Ukrainian NPP equipment

International Nuclear Information System (INIS)

Pecheritsa, A.V.; Inyushev, V.V.

1999-01-01

In the article materials a description of the basic sources of the information, which can be applied under a collection of the operational data on the defects of the Ukrainian NPP equipment, has been presented. The classification of mentioned sources is performed. The advantages and disadvantages of every of the specified sources are described. An finding regarding to a volume of the information about the defects of Safety Significant Systems equipment, which can be obtained under analysis of the different types of the sources, are presented

Imaging techniques for visualizing and phenotyping congenital heart defects in murine models.

Science.gov (United States)

Liu, Xiaoqin; Tobita, Kimimasa; Francis, Richard J B; Lo, Cecilia W

2013-06-01

Mouse model is ideal for investigating the genetic and developmental etiology of congenital heart disease. However, cardiovascular phenotyping for the precise diagnosis of structural heart defects in mice remain challenging. With rapid advances in imaging techniques, there are now high throughput phenotyping tools available for the diagnosis of structural heart defects. In this review, we discuss the efficacy of four different imaging modalities for congenital heart disease diagnosis in fetal/neonatal mice, including noninvasive fetal echocardiography, micro-computed tomography (micro-CT), micro-magnetic resonance imaging (micro-MRI), and episcopic fluorescence image capture (EFIC) histopathology. The experience we have gained in the use of these imaging modalities in a large-scale mouse mutagenesis screen have validated their efficacy for congenital heart defect diagnosis in the tiny hearts of fetal and newborn mice. These cutting edge phenotyping tools will be invaluable for furthering our understanding of the developmental etiology of congenital heart disease. Copyright © 2013 Wiley Periodicals, Inc.

Effects of in-cascade defect clustering on near-term defect evolution

Energy Technology Data Exchange (ETDEWEB)

Heinisch, H.L. [Pacific Northwest National Lab., Richland, WA (United States)

1997-08-01

The effects of in-cascade defect clustering on the nature of the subsequent defect population are being studied using stochastic annealing simulations applied to cascades generated in molecular dynamics (MD) simulations. The results of the simulations illustrates the strong influence of the defect configuration existing in the primary damage state on subsequent defect evolution. The large differences in mobility and stability of vacancy and interstitial defects and the rapid one-dimensional diffusion of small, glissile interstitial loops produced directly in cascades have been shown to be significant factors affecting the evolution of the defect distribution. In recent work, the effects of initial cluster sizes appear to be extremely important.

Spin helical states and spin transport of the line defect in silicene lattice

Energy Technology Data Exchange (ETDEWEB)

Yang, Mou; Chen, Dong-Hai; Wang, Rui-Qiang [Laboratory of Quantum Engineering and Quantum Materials, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006 (China); Bai, Yan-Kui, E-mail: ykbai@semi.ac.cn [College of Physical Science and Information Engineering and Hebei Advance Thin Films Laboratory, Hebei Normal University, Shijiazhuang, Hebei 050024 (China)

2015-02-06

We investigated the electronic structure of a silicene-like lattice with a line defect under the consideration of spin–orbit coupling. In the bulk energy gap, there are defect related bands corresponding to spin helical states localized beside the defect line: spin-up electrons flow forward on one side near the line defect and move backward on the other side, and vice versa for spin-down electrons. When the system is subjected to random distribution of spin-flipping scatterers, electrons suffer much less spin-flipped scattering when they transport along the line defect than in the bulk. An electric gate above the line defect can tune the spin-flipped transmission, which makes the line defect as a spin-controllable waveguide. - Highlights: • Band structure of silicene with a line defect. • Spin helical states around the line defect and their probability distribution features. • Spin transport along the line defect and that in the bulk silicene.

Mitochondrial respiratory chain Complex I defects in Fanconi anemia complementation group A.

Science.gov (United States)

Ravera, Silvia; Vaccaro, Daniele; Cuccarolo, Paola; Columbaro, Marta; Capanni, Cristina; Bartolucci, Martina; Panfoli, Isabella; Morelli, Alessandro; Dufour, Carlo; Cappelli, Enrico; Degan, Paolo

2013-10-01

Fanconi anemia (FA) is a rare and complex inherited blood disorder of the child. At least 15 genes are associated with the disease. The highest frequency of mutations belongs to groups A, C and G. Genetic instability and cytokine hypersensitivity support the selection of leukemic over non-leukemic stem cells. FA cellular phenotype is characterized by alterations in red-ox state, mitochondrial functionality and energy metabolism as reported in the past however a clear picture of the altered biochemical phenotype in FA is still elusive and the final biochemical defect(s) still unknown. Here we report an analysis of the respiratory fluxes in FANCA primary fibroblasts, lymphocytes and lymphoblasts. FANCA mutants show defective respiration through Complex I, diminished ATP production and metabolic sufferance with an increased AMP/ATP ratio. Respiration in FANCC mutants is normal. Treatment with N-acetyl-cysteine (NAC) restores oxygen consumption to normal level. Defective respiration in FANCA mutants appear correlated with the FA pro-oxidative phenotype which is consistent with the altered morphology of FANCA mitochondria. Electron microscopy measures indeed show profound alterations in mitochondrial ultrastructure and shape. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Geoepidemiology, Genetic and Environmental Risk Factors for PBC.

Science.gov (United States)

Zhang, Haiyan; Carbone, Marco; Lleo, Ana; Invernizzi, Pietro

2015-01-01

Primary biliary cirrhosis (PBC) is the most paradigmatic autoimmune liver disease with still several controversial issues in epidemiology, diagnosis, causation, and therapy. Although we are witnessing an enormous increase in the quantum of our basic knowledge of the disease with an initial translation in clinical practice, there are still a number of key open questions in PBC. Among them are the following questions: Why are there vast geographical variations in disease frequency? What are the reasons for female preponderance? Why do only small-size bile ducts get affected: What is the real role of genetics and epigenetics in its development? In particular, the prevalence of PBC is known to vary both on an international and a regional level, suggesting the existence of substantive geographical differences in terms of genetic susceptibility and environmental factors. New theories on potential environmental triggers, such as chemical xenobiotics, which lead to the breaking of self-tolerance within a unique immunological milieu of the liver, have been suggested. On the other hand, new and solid data on the genetic architecture of PBC are now obtained from recent high-throughput studies, together with data on sex chromosomes defects, and epigenetic abnormalities, thus strongly suggesting a role of genetic and epigenetic factors in the triggering and perpetuation of the autoimmune aggression in PBC. Based on these evidences, a number of novel drugs directed against specific immune-related molecules are currently under development. In this paper, we review a comprehensive collection of current epidemiological reports from various world regions. We also discuss here the most recent data regarding candidate genetic and environmental risk factors for PBC. © 2015 S. Karger AG, Basel.

Gordon Research Conference on Genetic Toxicology

Energy Technology Data Exchange (ETDEWEB)

Project Director Penelope Jeggo

2003-02-15

Genetic toxicology represents a study of the genetic damage that a cell can incur, the agents that induce such damage, the damage response mechanisms available to cells and organisms, and the potential consequences of such damage. Genotoxic agents are abundant in the environment and are also induced endogenously. The consequences of such damage can include carcinogenesis and teratogenesis. An understanding of genetic toxicology is essential to carry out risk evaluations of the impact of genotoxic agents and to assess how individual genetic differences influence the response to genotoxic damage. In recent years, the importance of maintaining genomic stability has become increasingly recognized, in part by the realization that failure of the damage response mechanisms underlies many, if not all, cancer incidence. The importance of these mechanisms is also underscored by their remarkable conservation between species, allowing the study of simple organisms to provide significant input into our understanding of the underlying mechanisms. It has also become clear that the damage response mechanisms interface closely with other aspects of cellular metabolism including replication, transcription and cell cycle regulation. Moreover, defects in many of these mechanisms, as observed for example in ataxia telangiectasia patients, confer disorders with associated developmental abnormalities demonstrating their essential roles during growth and development. In short, while a decade ago, a study of the impact of DNA damage was seen as a compartmentalized area of cellular research, it is now appreciated to lie at the centre of an array of cellular responses of crucial importance to human health. Consequently, this has become a dynamic and rapidly advancing area of research. The Genetic Toxicology Gordon Research Conference is biannual with an evolving change in the emphasis of the meetings. From evaluating the nature of genotoxic chemicals, which lay at the centre of the early

The App-Runx1 region is critical for birth defects and electrocardiographic dysfunctions observed in a Down syndrome mouse model.

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Matthieu Raveau

2012-05-01

Full Text Available Down syndrome (DS leads to complex phenotypes and is the main genetic cause of birth defects and heart diseases. The Ts65Dn DS mouse model is trisomic for the distal part of mouse chromosome 16 and displays similar features with post-natal lethality and cardiovascular defects. In order to better understand these defects, we defined electrocardiogram (ECG with a precordial set-up, and we found conduction defects and modifications in wave shape, amplitudes, and durations in Ts65Dn mice. By using a genetic approach consisting of crossing Ts65Dn mice with Ms5Yah mice monosomic for the App-Runx1 genetic interval, we showed that the Ts65Dn viability and ECG were improved by this reduction of gene copy number. Whole-genome expression studies confirmed gene dosage effect in Ts65Dn, Ms5Yah, and Ts65Dn/Ms5Yah hearts and showed an overall perturbation of pathways connected to post-natal lethality (Coq7, Dyrk1a, F5, Gabpa, Hmgn1, Pde10a, Morc3, Slc5a3, and Vwf and heart function (Tfb1m, Adam19, Slc8a1/Ncx1, and Rcan1. In addition cardiac connexins (Cx40, Cx43 and sodium channel sub-units (Scn5a, Scn1b, Scn10a were found down-regulated in Ts65Dn atria with additional down-regulation of Cx40 in Ts65Dn ventricles and were likely contributing to conduction defects. All these data pinpoint new cardiac phenotypes in the Ts65Dn, mimicking aspects of human DS features and pathways altered in the mouse model. In addition they highlight the role of the App-Runx1 interval, including Sod1 and Tiam1, in the induction of post-natal lethality and of the cardiac conduction defects in Ts65Dn. These results might lead to new therapeutic strategies to improve the care of DS people.

Mechanical properties of highly defective graphene: from brittle rupture to ductile fracture.

Science.gov (United States)

Xu, Lanqing; Wei, Ning; Zheng, Yongping

2013-12-20

Defects are generally believed to deteriorate the superlative performance of graphene-based devices but may also be useful when carefully engineered to tailor the local properties and achieve new functionalities. Central to most defect-associated applications is the defect coverage and arrangement. In this work, we investigate, by molecular dynamics simulations, the mechanical properties and fracture dynamics of graphene sheets with randomly distributed vacancies or Stone-Wales defects under tensile deformations over a wide defect coverage range. With defects presented, an sp-sp(2) bonding network and an sp-sp(2)-sp(3) bonding network are observed in vacancy-defected and Stone-Wales-defected graphene, respectively. The ultimate strength degrades gradually with increasing defect coverage and saturates in the high-ratio regime, whereas the fracture strain presents an unusual descending-saturating-improving trend. In the dense vacancy defect situation, the fracture becomes more plastic and super-ductility is observed. Further fracture dynamics analysis reveals that the crack trapping by sp-sp(2) and sp-sp(2)-sp(3) rings and the crack-tip blunting account for the ductile fracture, whereas geometric rearrangement on the entire sheet for vacancy defects and geometric rearrangement on the specific defect sites for Stone-Wales defects account for their distinctive rules of the evolution of the fracture strain.

Shared activity patterns arising at genetic susceptibility loci reveal underlying genomic and cellular architecture of human disease

DEFF Research Database (Denmark)

Baillie, J. Kenneth; Bretherick, Andrew; Haley, Christopher S.

2018-01-01

Genetic variants underlying complex traits, including disease susceptibility, are enriched within the transcriptional regulatory elements, promoters and enhancers. There is emerging evidence that regulatory elements associated with particular traits or diseases share similar patterns of transcrip...

Ultrasonic test data acquisition and defect verification of stainless-steel welds at 4000F

International Nuclear Information System (INIS)

Mech, S.J.

1983-01-01

This paper describes techniques developed to characterize the features found during ultrasonic examination of stainless steel welds which are indicative of defects. Feature inspection technology allows reliable discrimination weld signals and other noise under remote, automatic, high temperature conditions. Ultrasonic feature inspection techniques have been successfully implemented under 400 0 F (200 0 C) flowing sodium pipe welds. The challenge is to develop techniques which find defects, but ignore variations associated with the normal cast type microstructure of the weld zone. This study was directed at gathering data on a welded pipe section with notches used to simulate defects and is an example of computer acquisition and analysis techniques of ultrasonic data. Various analysis methods were compared to find signal analysis algorithms sensitive to these simulated defects

Dirichlet topological defects

International Nuclear Information System (INIS)

Carroll, S.M.; Trodden, M.

1998-01-01

We propose a class of field theories featuring solitonic solutions in which topological defects can end when they intersect other defects of equal or higher dimensionality. Such configurations may be termed open-quotes Dirichlet topological defects,close quotes in analogy with the D-branes of string theory. Our discussion focuses on defects in scalar field theories with either gauge or global symmetries, in 3+1 dimensions; the types of defects considered include walls ending on walls, strings on walls, and strings on strings. copyright 1998 The American Physical Society

Issues in first-principles calculations for defects in semiconductors and oxides

International Nuclear Information System (INIS)

Nieminen, Risto M

2009-01-01

Recent advances in density-functional theory (DFT) calculations of defect electronic properties in semiconductors and insulators are discussed. In particular, two issues are addressed: the band-gap underestimation of standard density-functional methods with its harmful consequences for the positioning of defect-related levels in the band-gap region, and the slow convergence of calculated defect properties when the periodic supercell approach is used. Systematic remedies for both of these deficiencies are now available, and are being implemented in the context of popular DFT codes. This should help in improving the parameter-free accuracy and thus the predictive power of the methods to enable unambiguous explanation of defect-related experimental observations. These include not only the various fingerprint spectroscopies for defects but also their thermochemistry and dynamics, i.e. the temperature-dependent concentration and diffusivities of defects under various doping conditions and in different stoichiometries

3D modeling of missing pellet surface defects in BWR fuel

Energy Technology Data Exchange (ETDEWEB)

Spencer, B.W., E-mail: Benjamin.Spencer@inl.gov; Williamson, R.L.; Stafford, D.S.; Novascone, S.R.; Hales, J.D.; Pastore, G.

2016-10-15

Highlights: • A global/local analysis procedure for missing pellet surface defects is proposed. • This is applied to defective BWR fuel under blade withdrawal and high power ramp conditions. • Sensitivity of the cladding response to key model parameters is studied. - Abstract: One of the important roles of cladding in light water reactor fuel rods is to prevent the release of fission products. To that end, it is essential that the cladding maintain its integrity under a variety of thermal and mechanical loading conditions. Local geometric irregularities in fuel pellets caused by manufacturing defects known as missing pellet surfaces (MPS) can in some circumstances lead to elevated cladding stresses that are sufficiently high to cause cladding failure. Accurate modeling of these defects can help prevent these types of failures. The BISON nuclear fuel performance code developed at Idaho National Laboratory can be used to simulate the global thermo-mechanical fuel rod behavior, as well as the local response of regions of interest, in either 2D or 3D. In either case, a full set of models to represent the thermal and mechanical properties of the fuel, cladding and plenum gas is employed. A procedure for coupling 2D full-length fuel rod models to detailed 3D models of the region of the rod containing a MPS defect is detailed here. The global and local model each contain appropriate physics and behavior models for nuclear fuel. This procedure is demonstrated on a simulation of a boiling water reactor (BWR) fuel rod containing a pellet with an MPS defect, subjected to a variety of transient events, including a control blade withdrawal and a ramp to high power. The importance of modeling the local defect using a 3D model is highlighted by comparing 3D and 2D representations of the defective pellet region. Parametric studies demonstrate the effects of the choice of gaseous swelling model and of the depth and geometry of the MPS defect on the response of the cladding

Defects and defect generation in oxide layer of ion implanted silicon-silicon dioxide structures

CERN Document Server

Baraban, A P

2002-01-01

One studies mechanism of generation of defects in Si-SiO sub 2 structure oxide layer as a result of implantation of argon ions with 130 keV energy and 10 sup 1 sup 3 - 3.2 x 10 sup 1 sup 7 cm sup - sup 2 doses. Si-SiO sub 2 structures are produced by thermal oxidation of silicon under 950 deg C temperature. Investigations were based on electroluminescence technique and on measuring of high-frequency volt-farad characteristics. Increase of implantation dose was determined to result in spreading of luminosity centres and in its maximum shifting closer to boundary with silicon. Ion implantation was shown, as well, to result in increase of density of surface states at Si-SiO sub 2 interface. One proposed model of defect generation resulting from Ar ion implantation into Si-SiO sub 2

Mapping QTL for Seed Germinability under Low Temperature Using a New High-Density Genetic Map of Rice

Directory of Open Access Journals (Sweden)

Ningfei Jiang

2017-07-01

Full Text Available Mapping major quantitative trait loci (QTL responsible for rice seed germinability under low temperature (GULT can provide valuable genetic source for improving cold tolerance in rice breeding. In this study, 124 rice backcross recombinant inbred lines (BRILs derived from a cross indica cv. Changhui 891 and japonica cv. 02428 were genotyped through re-sequencing technology. A bin map was generated which includes 3057 bins covering distance of 1266.5 cM with an average of 0.41 cM between markers. On the basis of newly constructed high-density genetic map, six QTL were detected ranging from 40 to 140 kb on Nipponbare genome. Among these, two QTL qCGR8 and qGRR11 alleles shared by 02428 could increase GULT and seed germination recovery rate after cold stress, respectively. However, qNGR1 and qNGR4 may be two major QTL affecting indica Changhui 891germination under normal condition. QTL qGRR1 and qGRR8 affected the seed germination recovery rate after cold stress and the alleles with increasing effects were shared by the Changhui 891 could improve seed germination rate after cold stress dramatically. These QTL could be a highly valuable genetic factors for cold tolerance improvement in rice lines. Moreover, the BRILs developed in this study will serve as an appropriate choice for mapping and studying genetic basis of rice complex traits.

Genetic complexity underlying hybrid male sterility in Drosophila.

Science.gov (United States)

Sawamura, Kyoichi; Roote, John; Wu, Chung-I; Yamamoto, Masa-Toshi

2004-02-01

Recent genetic analyses of closely related species of Drosophila have indicated that hybrid male sterility is the consequence of highly complex synergistic effects among multiple genes, both conspecific and heterospecific. On the contrary, much evidence suggests the presence of major genes causing hybrid female sterility and inviability in the less-related species, D. melanogaster and D. simulans. Does this contrast reflect the genetic distance between species? Or, generally, is the genetic basis of hybrid male sterility more complex than that of hybrid female sterility and inviability? To clarify this point, the D. simulans introgression of the cytological region 34D-36A to the D. melanogaster genome, which causes recessive male sterility, was dissected by recombination, deficiency, and complementation mapping. The 450-kb region between two genes, Suppressor of Hairless and snail, exhibited a strong effect on the sterility. Males are (semi-)sterile if this region of the introgression is made homozygous or hemizygous. But no genes in the region singly cause the sterility; this region has at least two genes, which in combination result in male sterility. Further, the males are less fertile when heterozygous with a larger introgression, which suggests that dominant modifiers enhance the effects of recessive genes of male sterility. Such an epistatic view, even in the less-related species, suggests that the genetic complexity is special to hybrid male sterility.

Defect detection in conducting materials using eddy current testing techniques

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Brauer Hartmut

2014-01-01

Full Text Available Lorentz force eddy current testing (LET is a novel nondestructive testing technique which can be applied preferably to the identification of internal defects in nonmagnetic moving conductors. The LET is compared (similar testing conditions with the classical eddy current testing (ECT. Numerical FEM simulations have been performed to analyze the measurements as well as the identification of internal defects in nonmagnetic conductors. The results are compared with measurements to test the feasibility of defect identification. Finally, the use of LET measurements to estimate of the electrical conductors under test are described as well.

Defect forces, defect couples and path integrals in fracture mechanics

International Nuclear Information System (INIS)

Roche, R.L.

1979-07-01

In this work, it is shown that the path integrals can be introduced without any reference to the material behavior. The method is based on the definition in a continuous medium of a set of vectors and couples having the dimension of a force or a moment. More precisely, definitions are given of volume defect forces, surface defect forces, volume defect couples, and surface defect couples. This is done with the help of the stress working variation of a particule moving through the solid. The most important result is: the resultant of all the defect forces included in a volume V is the J integral on the surface surrounding V and the moment resultant is the L integral. So these integrals are defined without any assumption on the material constitutive equation. Another result is the material form of the virtual work principle - defect forces are acting like conventional forces in the conventional principles of virtual work. This lead to the introduction of the energy momentum tensor and of the associated couple stress. Application of this method is made to fracture mechanics in studying the defect forces distribution around a crack [fr

Exome sequencing in 32 patients with anophthalmia/microphthalmia and developmental eye defects.

Science.gov (United States)

Slavotinek, A M; Garcia, S T; Chandratillake, G; Bardakjian, T; Ullah, E; Wu, D; Umeda, K; Lao, R; Tang, P L-F; Wan, E; Madireddy, L; Lyalina, S; Mendelsohn, B A; Dugan, S; Tirch, J; Tischler, R; Harris, J; Clark, M J; Chervitz, S; Patwardhan, A; West, J M; Ursell, P; de Alba Campomanes, A; Schneider, A; Kwok, P-Y; Baranzini, S; Chen, R O

2015-11-01

Anophthalmia/microphthalmia (A/M) is a genetically heterogeneous birth defect for which the etiology is unknown in more than 50% of patients. We used exome sequencing with the ACE Exome(TM) (Personalis, Inc; 18 cases) and UCSF Genomics Core (21 cases) to sequence 28 patients with A/M and four patients with varied developmental eye defects. In the 28 patients with A/M, we identified de novo mutations in three patients (OTX2, p.(Gln91His), RARB, p.Arg387Cys and GDF6, p.Ala249Glu) and inherited mutations in STRA6 in two patients. In patients with developmental eye defects, a female with cataracts and cardiomyopathy had a de novo COL4A1 mutation, p.(Gly773Arg), expanding the phenotype associated with COL4A1 to include cardiomyopathy. A male with a chorioretinal defect, microcephaly, seizures and sensorineural deafness had two PNPT1 mutations, p.(Ala507Ser) and c.401-1G>A, and we describe eye defects associated with this gene for the first time. Exome sequencing was efficient for identifying mutations in pathogenic genes for which there is no clinical testing available and for identifying cases that expand phenotypic spectra, such as the PNPT1 and COL4A1-associated disorders described here. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

X-linked NDUFA1 gene mutations associated with mitochondrial encephalomyopathy.

NARCIS (Netherlands)

Fernandez-Moreira, D.; Ugalde, C.; Smeets, R.; Rodenburg, R.J.T.; Lopez-Laso, E.; Ruiz-Falco, M.L.; Briones, P.; Martin, M.A.; Smeitink, J.A.M.; Arenas, J.

2007-01-01

OBJECTIVE: Mitochondrial complex I deficiency is the commonest diagnosed respiratory chain defect, being genetically heterogeneous. The male preponderance of previous patient cohorts suggested an X-linked underlying genetic defect. We investigated mutations in the X-chromosomal complex I structural

Sigma models in the presence of dynamical point-like defects

International Nuclear Information System (INIS)

Doikou, Anastasia; Karaiskos, Nikos

2013-01-01

Point-like Liouville integrable dynamical defects are introduced in the context of the Landau–Lifshitz and Principal Chiral (Faddeev–Reshetikhin) models. Based primarily on the underlying quadratic algebra we identify the first local integrals of motion, the associated Lax pairs as well as the relevant sewing conditions around the defect point. The involution of the integrals of motion is shown taking into account the sewing conditions.

Neural Tube Defects

Science.gov (United States)

Neural tube defects are birth defects of the brain, spine, or spinal cord. They happen in the ... that she is pregnant. The two most common neural tube defects are spina bifida and anencephaly. In ...

Recent advances in preimplantation genetic diagnosis

Directory of Open Access Journals (Sweden)

Kahraman S

2015-04-01

Full Text Available Semra Kahraman, Çağri Beyazyürek, Hüseyin Avni Taç, Caroline Pirkevi, Murat Cetinkaya, Neşe Gülüm IVF and Reproductive Genetics Center, Istanbul Memorial Hospital, Istanbul, Turkey Abstract: Preimplantation genetic diagnosis (PGD is an important method for the identification chromosomal abnormalities and genes responsible for genetic defects in embryos that are created through in vitro fertilization before pregnancy. As the list of conditions and indications for PGD testing is continuing to extend enormously, novel in vitro fertilization techniques and newly established genetic analysis techniques have been implemented in clinical settings in the recent years. Blastocyst-stage biopsy, vitrification techniques, time-lapse imaging, whole-genome amplification, array-based diagnostic techniques, and next-generation sequencing techniques are promising techniques for the accurate diagnosis of diverse genetic conditions and also for the selection of the best embryo that has the highest implantation capacity. The timing and technique used for biopsy, the amplification techniques, the genetic diagnosis techniques, and appropriate genetic counseling play important roles in establishing a successful PGD. In this review, those key points of PGD will be reviewed in detail. Keywords: preimplantation genetic diagnosis, array comparative genomic hybridization, single-nucleotide polymorphism arrays, next-generation sequencing, monogenic disorders, aneuploidy testing 

Kinetics of interstitial defects in α-Fe: The effect from uniaxial stress

Energy Technology Data Exchange (ETDEWEB)

Kang, Changwoo [Department of Nuclear Engineering, Texas A& M University, College Station, TX 77843 (United States); Wang, Qingyu [College of Nuclear Science and Technology, Harbin Engineering University, Harbin 150001 (China); Shao, Lin, E-mail: lshao@tamu.edu [Department of Nuclear Engineering, Texas A& M University, College Station, TX 77843 (United States)

2017-03-15

Understanding defect kinetics in a stress field is important for multiscale modeling of materials degradation of nuclear materials. By means of molecular dynamics and molecular statics simulations, we calculate formation and migration energies of self-interstitial atoms (SIA) and SIA clusters (up to size of 5 interstitials) in alpha Fe and identify their stable configurations under uniaxial tensile strains. By applying uniaxial stress along [111], <111> oriented single SIA defects become more stable than <110> oriented SIA, which is opposite to stress-free condition. Diffusion of single SIA defects under [111] tensile stress is facilitated along [111] direction and the diffusion becomes one dimensional (1D). For SIA clusters, their diffusion under zero stress has gradual transition from three dimensional (3D) for small clusters to one dimensional (1D) for large clusters. Under the tensile stress along [111], the 3D to 1D transition is accelerated. For large SIA clusters, the stress effect is quickly saturated with less diffusivity enhancement in comparison with small SIA clusters.

Genetics and molecular pathology of Stargardt-like macular degeneration.

Science.gov (United States)

Vasireddy, Vidyullatha; Wong, Paul; Ayyagari, Radha

2010-05-01

Stargardt-like macular degeneration (STGD3) is an early onset, autosomal dominant macular degeneration. STGD3 is characterized by a progressive pathology, the loss of central vision, atrophy of the retinal pigment epithelium, and accumulation of lipofuscin, clinical features that are also characteristic of age-related macular degeneration. The onset of clinical symptoms in STGD3, however, is typically observed within the second or third decade of life (i.e., starting in the teenage years). The clinical profile at any given age among STGD3 patients can be variable suggesting that, although STGD3 is a single gene defect, other genetic or environmental factors may play a role in moderating the final disease phenotype. Genetic studies localized the STGD3 disease locus to a small region on the short arm of human chromosome 6, and application of a positional candidate gene approach identified protein truncating mutations in the elongation of very long chain fatty acids-4 gene (ELOVL4) in patients with this disease. The ELOVL4 gene encodes a protein homologous to the ELO group of proteins that participate in fatty acid elongation in yeast. Pathogenic mutations found in the ELOVL4 gene result in altered trafficking of the protein and behave with a dominant negative effect. Mice carrying an Elovl4 mutation developed photoreceptor degeneration and depletion of very long chain fatty acids (VLCFA). ELOVL4 protein participates in the synthesis of fatty acids with chain length longer than 26 carbons. Studies on ELOVL4 indicate that VLCFA may be necessary for normal function of the retina, and the defective protein trafficking and/or altered VLCFA elongation underlies the pathology associated with STGD3. Determining the role of VLCFA in the retina and discerning the implications of abnormal trafficking of mutant ELOVL4 and depleted VLCFA content in the pathology of STGD3 will provide valuable insight in understanding the retinal structure, function, and pathology underlying STGD3

Steady distribution structure of point defects near crystal-melt interface under pulling stop of CZ Si crystal

Science.gov (United States)

Abe, T.; Takahashi, T.; Shirai, K.

2017-02-01

In order to reveal a steady distribution structure of point defects of no growing Si on the solid-liquid interface, the crystals were grown at a high pulling rate, which Vs becomes predominant, and the pulling was suddenly stopped. After restoring the variations of the crystal by the pulling-stop, the crystals were then left in prolonged contact with the melt. Finally, the crystals were detached and rapidly cooled to freeze point defects and then a distribution of the point defects of the as-grown crystals was observed. As a result, a dislocation loop (DL) region, which is formed by the aggregation of interstitials (Is), was formed over the solid-liquid interface and was surrounded with a Vs-and-Is-free recombination region (Rc-region), although the entire crystals had been Vs rich in the beginning. It was also revealed that the crystal on the solid-liquid interface after the prolonged contact with the melt can partially have a Rc-region to be directly in contact with the melt, unlike a defect distribution of a solid-liquid interface that has been growing. This experimental result contradicts a hypothesis of Voronkov's diffusion model, which always assumes the equilibrium concentrations of Vs and Is as the boundary condition for distribution of point defects on the growth interface. The results were disscussed from a qualitative point of view of temperature distribution and thermal stress by the pulling-stop.

Worms under stress: unravelling genetic complex traits through perturbation

NARCIS (Netherlands)

Rodriguez Sanchez, M.

2014-01-01

The genetic architecture of an organism could be considered ‘the most amazing piece of engineering’ existing in nature. Looking from a certain distance, the genetic complexity of an organism could be described as an immense jigsaw puzzle. As in a real jigsaw, the connection between two pieces

Sardinians genetic background explained by runs of homozygosity and genomic regions under positive selection.

Directory of Open Access Journals (Sweden)

Cornelia Di Gaetano

Full Text Available The peculiar position of Sardinia in the Mediterranean sea has rendered its population an interesting biogeographical isolate. The aim of this study was to investigate the genetic population structure, as well as to estimate Runs of Homozygosity and regions under positive selection, using about 1.2 million single nucleotide polymorphisms genotyped in 1077 Sardinian individuals. Using four different methods--fixation index, inflation factor, principal component analysis and ancestry estimation--we were able to highlight, as expected for a genetic isolate, the high internal homogeneity of the island. Sardinians showed a higher percentage of genome covered by RoHs>0.5 Mb (F(RoH%0.5 when compared to peninsular Italians, with the only exception of the area surrounding Alghero. We furthermore identified 9 genomic regions showing signs of positive selection and, we re-captured many previously inferred signals. Other regions harbor novel candidate genes for positive selection, like TMEM252, or regions containing long non coding RNA. With the present study we confirmed the high genetic homogeneity of Sardinia that may be explained by the shared ancestry combined with the action of evolutionary forces.

Genetic modification of chondrocytes with insulin-like growth factor-1 enhances cartilage healing in an equine model.

Science.gov (United States)

Goodrich, L R; Hidaka, C; Robbins, P D; Evans, C H; Nixon, A J

2007-05-01

Gene therapy with insulin-like growth factor-1 (IGF-1) increases matrix production and enhances chondrocyte proliferation and survival in vitro. The purpose of this study was to determine whether arthroscopically-grafted chondrocytes genetically modified by an adenovirus vector encoding equine IGF-1 (AdIGF-1) would have a beneficial effect on cartilage healing in an equine femoropatellar joint model. A total of 16 horses underwent arthroscopic repair of a single 15 mm cartilage defect in each femoropatellar joint. One joint received 2 x 10(7) AdIGF-1 modified chondrocytes and the contralateral joint received 2 x 10(7) naive (unmodified) chondrocytes. Repairs were analysed at four weeks, nine weeks and eight months after surgery. Morphological and histological appearance, IGF-1 and collagen type II gene expression (polymerase chain reaction, in situ hybridisation and immunohistochemistry), collagen type II content (cyanogen bromide and sodium dodecyl sulphate-polyacrylamide gel electrophoresis), proteoglycan content (dimethylmethylene blue assay), and gene expression for collagen type I, matrix metalloproteinase (MMP)-1, MMP-3, MMP-13, aggrecanase-1, tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and TIMP-3 were evaluated. Genetic modification of chondrocytes significantly increased IGF-1 mRNA and ligand production in repair tissue for up to nine weeks following transplantation. The gross and histological appearance of IGF-1 modified repair tissue was improved over control defects. Gross filling of defects was significantly improved at four weeks, and a more hyaline-like tissue covered the lesions at eight months. Histological outcome at four and nine weeks post-transplantation revealed greater tissue filling of defects transplanted with genetically modified chondrocytes, whereas repair tissue in control defects was thin and irregular and more fibrous. Collagen type II expression in IGF-1 gene-transduced defects was increased 100-fold at four weeks and

Genetic influence on blood pressure measured in the office, under laboratory stress and during real life

NARCIS (Netherlands)

Wang, Xiaoling; Ding, Xiuhua; Su, Shaoyong; Harshfield, Gregory; Treiber, Frank; Snieder, Harold

To determine to what extent the genetic influences on blood pressure (BP) measured in the office, under psychologically stressful conditions in the laboratory and during real life are different from each other. Office BP, BP during a video game challenge and a social stressor interview, and 24-h

The Correlation Between Dislocations and Vacancy Defects Using Positron Annihilation Spectroscopy

Science.gov (United States)

Pang, Jinbiao; Li, Hui; Zhou, Kai; Wang, Zhu

2012-07-01

An analysis program for positron annihilation lifetime spectra is only applicable to isolated defects, but is of no use in the presence of defective correlations. Such limitations have long caused problems for positron researchers in their studies of complicated defective systems. In order to solve this problem, we aim to take a semiconductor material, for example, to achieve a credible average lifetime of single crystal silicon under plastic deformation at different temperatures using positron life time spectroscopy. By establishing reasonable positron trapping models with defective correlations and sorting out four lifetime components with multiple parameters, as well as their respective intensities, information is obtained on the positron trapping centers, such as the positron trapping rates of defects, the density of the dislocation lines and correlation between the dislocation lines, and the vacancy defects, by fitting with the average lifetime with the aid of Matlab software. These results give strong grounds for the existence of dislocation-vacancy correlation in plastically deformed silicon, and lay a theoretical foundation for the analysis of positron lifetime spectra when the positron trapping model involves dislocation-related defects.

Syndromic aspects of testicular carcinoma

NARCIS (Netherlands)

Lutke-Holzik, MF; Sijmons, RH; Sleijfer, DT; Sonneveld, DJA; Hoekstra-Weebers, JEHM; van Echten-Arends, J; Hoekstra, HJ

2003-01-01

BACKGROUND. In patients with hereditary or constitutional chromosomal anomalies, testicular carcinoma can develop sporadically or on the basis of an underlying hereditary genetic defect. Greater knowledge of these genetic defects would provide more insight into the molecular pathways that lead to

CCDC115 Deficiency Causes a Disorder of Golgi Homeostasis with Abnormal Protein Glycosylation

NARCIS (Netherlands)

Jansen, Jos C.; Cirak, Sebahattin; van Scherpenzeel, Monique; Timal, Sharita; Reunert, Janine; Rust, Stephan; Pérez, Belén; Vicogne, Dorothée; Krawitz, Peter; Wada, Yoshinao; Ashikov, Angel; Pérez-Cerdá, Celia; Medrano, Celia; Arnoldy, Andrea; Hoischen, Alexander; Huijben, Karin; Steenbergen, Gerry; Quelhas, Dulce; Diogo, Luisa; Rymen, Daisy; Jaeken, Jaak; Guffon, Nathalie; Cheillan, David; van den Heuvel, Lambertus P.; Maeda, Yusuke; Kaiser, Olaf; Schara, Ulrike; Gerner, Patrick; van den Boogert, Marjolein A. W.; Holleboom, Adriaan G.; Nassogne, Marie-Cécile; Sokal, Etienne; Salomon, Jody; van den Bogaart, Geert; Drenth, Joost P. H.; Huynen, Martijn A.; Veltman, Joris A.; Wevers, Ron A.; Morava, Eva; Matthijs, Gert; Foulquier, François; Marquardt, Thorsten; Lefeber, Dirk J.

2016-01-01

Disorders of Golgi homeostasis form an emerging group of genetic defects. The highly heterogeneous clinical spectrum is not explained by our current understanding of the underlying cell-biological processes in the Golgi. Therefore, uncovering genetic defects and annotating gene function are

Mechanical properties of highly defective graphene: from brittle rupture to ductile fracture

International Nuclear Information System (INIS)

Xu, Lanqing; Wei, Ning; Zheng, Yongping

2013-01-01

Defects are generally believed to deteriorate the superlative performance of graphene-based devices but may also be useful when carefully engineered to tailor the local properties and achieve new functionalities. Central to most defect-associated applications is the defect coverage and arrangement. In this work, we investigate, by molecular dynamics simulations, the mechanical properties and fracture dynamics of graphene sheets with randomly distributed vacancies or Stone–Wales defects under tensile deformations over a wide defect coverage range. With defects presented, an sp–sp 2 bonding network and an sp–sp 2 –sp 3 bonding network are observed in vacancy-defected and Stone–Wales-defected graphene, respectively. The ultimate strength degrades gradually with increasing defect coverage and saturates in the high-ratio regime, whereas the fracture strain presents an unusual descending–saturating–improving trend. In the dense vacancy defect situation, the fracture becomes more plastic and super-ductility is observed. Further fracture dynamics analysis reveals that the crack trapping by sp–sp 2 and sp–sp 2 –sp 3 rings and the crack-tip blunting account for the ductile fracture, whereas geometric rearrangement on the entire sheet for vacancy defects and geometric rearrangement on the specific defect sites for Stone–Wales defects account for their distinctive rules of the evolution of the fracture strain. (paper)

Improvement of defect characterization in ultrasonic testing by adaptative learning network

International Nuclear Information System (INIS)

Bieth, M.; Adamonis, D.C.; Jusino, A.

1982-01-01

Numerous methods exist now for signal analysis in ultrasonic testing. These methods give more or less accurate information for defects characterization. In this paper is presented the development of a particular system based on a computer Signal processing: the Adaptative Learning Network (ALN) allowing the discrimination of defects in function of their nature. The ultrasonic signal is sampled and characterized by parameters amplitude-time and amplitude-frequency. The method was tested on stainless steel tubes welds showing fatigue cracks. The ALN model developed allows, under certain conditions, the discrimination of cracks from other defects [fr

On kinetics of paramagnetic radiation defects accumulation in beryllium ceramics

International Nuclear Information System (INIS)

Polyakov, A.I.; Ryabikin, Yu.A.; Zashkvara, O.V.; Bitenbaev, M.I.; Petykhov, Yu.V.

1999-01-01

Results of paramagnetic radiation defects concentration dependence study in beryllium ceramics from gamma-irradiation dose ( 60 Co) within interval 0-100 Mrem are cited. Obtained dose dependence has form of accumulation curve with saturation typical of for majority of solids (crystals, different polymers, organic substances and others) , in which under irradiation occur not only formation of paramagnetic radiation defects, but its destruction due to recombination and interaction with radiation fields. Analysis of accumulation curve by the method of distant asymptotics allows to determine that observed in gamma-irradiated beryllium ceramics double line of electron spin resonance is forming of two types of paramagnetic radiation defects. It was defined, that sum paramagnetic characteristics of beryllium ceramics within 1-100 Mrad gamma- irradiation dose field change insignificantly and define from first type of paramagnetic radiation defects

Evolution of Radiation Induced Defects in SiC: A Multiscale Simulation Approach

Science.gov (United States)

Jiang, Hao

temperatures beyond that. Even though clusters cannot diffuse by thermal vibrations, we found they can migrate at room temperature under the influence of electron radiation. This is the first direct observation of radiation-induced diffusion of defect clusters in bulk materials. We show that the underlying mechanism of this athermal diffusion is elastic collision between incoming electrons and cluster atoms. Our findings suggest that defect clusters may be mobile under certain irradiation conditions, changing current understanding of cluster annealing process in irradiated SiC. With the knowledge of cluster diffusion in SiC demonstrated in this thesis, we now become able to predict cluster evolution in SiC with good agreement with experimental measurements. This ability can enable us to estimate changes in many properties of irradiated SiC relevant for its applications in reactors. Internal interfaces such as grain boundaries can behave as sinks to radiation induced defects. The ability of GBs to absorb, transport, and annihilate radiation-induced defects (sink strength) is important to understand radiation response of polycrystalline materials and to better design interfaces for improved resistance to radiation damage. Nowadays, it is established GBs' sink strength is not a static property but rather evolves with many factors, including radiation environments, grain size, and GB microstructure. In this thesis, I investigated the response of small-angle tilt and twist GBs to point defects fluxes in SiC. First of all, I found the pipe diffusion of interstitials in tilt GBs is slower than bulk diffusion. This is because the increased interatomic distance at dislocation cores raises the migration barrier of interstitial dumbbells. Furthermore, I show that both the annihilation of interstitials at jogs and jog nucleation from clusters are diffusion-controlled and can occur under off-stoichiometric interstitial fluxes. Finally, a dislocation line model is developed to predict the

Hereditary multiple exostoses: from genetics to clinical syndrome and complications

Energy Technology Data Exchange (ETDEWEB)

Vanhoenacker, Filip M.; Hul, Wim van; Wuyts, Wim; Willems, P.J.; Schepper, Arthur M. de

2001-12-01

Objective: To give an overview of genetic, clinical and radiological aspects in two families over four generations with known hereditary multiple exostoses (HME). Methods and material: After linkage analysis in both families to localize the defective gene, mutation analysis was performed in these genes to identify the underlying mutation. In the 31 affected individuals, location, number and morphology and evolution of exostosis, evolution of remodeling defects at the metaphysis, and the extent of possible complications were evaluated on clinical and imaging (plain radiography, computed tomography (CT), and magnetic resonance imaging (MRI)) data over a lifetime period. Results and conclusions: Both families demonstrate the gene defect in the same EXT-2 gene locus on chromosome 11p. Exostoses are preferentially located in the lower extremity (hip, knee and lower leg), humerus, and forearm. Any other bone may be involved, except for the calvaria of the skull and the mandible. Exostoses are rather sessile than pedunculated. Exostosis is rarely present at birth but develops gradually and may persist to grow slowly after closure of the growth plates. Preferential expression of the remodeling defect was seen in the hip, distal femur (trumpet-shaped metaphysis) and forearm (shortening of the ulna with secondary bowing of the radius and development of a pseudo-Madelung deformity). These radiological manifestations start at the age of 4-5 years and become more obvious as the enchondral bone formation progresses with age. Reported complications in these families consist of local entrapment phenomenons (vessel, tendon, nerve), frictional bursitis, and sarcomatous transformation. MRI was able to suggest these complications and is the imaging technique of choice in the evaluation of symptomatic exostoses.

Hereditary multiple exostoses: from genetics to clinical syndrome and complications

International Nuclear Information System (INIS)

Vanhoenacker, Filip M.; Hul, Wim van; Wuyts, Wim; Willems, P.J.; Schepper, Arthur M. de

2001-01-01

Objective: To give an overview of genetic, clinical and radiological aspects in two families over four generations with known hereditary multiple exostoses (HME). Methods and material: After linkage analysis in both families to localize the defective gene, mutation analysis was performed in these genes to identify the underlying mutation. In the 31 affected individuals, location, number and morphology and evolution of exostosis, evolution of remodeling defects at the metaphysis, and the extent of possible complications were evaluated on clinical and imaging (plain radiography, computed tomography (CT), and magnetic resonance imaging (MRI)) data over a lifetime period. Results and conclusions: Both families demonstrate the gene defect in the same EXT-2 gene locus on chromosome 11p. Exostoses are preferentially located in the lower extremity (hip, knee and lower leg), humerus, and forearm. Any other bone may be involved, except for the calvaria of the skull and the mandible. Exostoses are rather sessile than pedunculated. Exostosis is rarely present at birth but develops gradually and may persist to grow slowly after closure of the growth plates. Preferential expression of the remodeling defect was seen in the hip, distal femur (trumpet-shaped metaphysis) and forearm (shortening of the ulna with secondary bowing of the radius and development of a pseudo-Madelung deformity). These radiological manifestations start at the age of 4-5 years and become more obvious as the enchondral bone formation progresses with age. Reported complications in these families consist of local entrapment phenomenons (vessel, tendon, nerve), frictional bursitis, and sarcomatous transformation. MRI was able to suggest these complications and is the imaging technique of choice in the evaluation of symptomatic exostoses

Defective glycinergic synaptic transmission in zebrafish motility mutants

Directory of Open Access Journals (Sweden)

Hiromi Hirata

2010-01-01

Full Text Available Glycine is a major inhibitory neurotransmitter in the spinal cord and brainstem. Recently, in vivo analysis of glycinergic synaptic transmission has been pursued in zebrafish using molecular genetics. An ENU mutagenesis screen identified two behavioral mutants that are defective in glycinergic synaptic transmission. Zebrafish bandoneon (beo mutants have a defect in glrbb, one of the duplicated glycine receptor (GlyR β subunit genes. These mutants exhibit a loss of glycinergic synaptic transmission due to a lack of synaptic aggregation of GlyRs. Due to the consequent loss of reciprocal inhibition of motor circuits between the two sides of the spinal cord, motor neurons activate simultaneously on both sides resulting in bilateral contraction of axial muscles of beo mutants, eliciting the so-called ‘accordion’ phenotype. Similar defects in GlyR subunit genes have been observed in several mammals and are the basis for human hyperekplexia/startle disease. By contrast, zebrafish shocked (sho mutants have a defect in slc6a9, encoding GlyT1, a glycine transporter that is expressed by astroglial cells surrounding the glycinergic synapse in the hindbrain and spinal cord. GlyT1 mediates rapid uptake of glycine from the synaptic cleft, terminating synaptic transmission. In zebrafish sho mutants, there appears to be elevated extracellular glycine resulting in persistent inhibition of postsynaptic neurons and subsequent reduced motility, causing the ‘twitch once’ phenotype. We review current knowledge regarding zebrafish ‘accordion’ and ‘twitch once’ mutants, including beo and sho, and report the identification of a new α2 subunit that revises the phylogeny of zebrafish GlyRs.

Defective Glycinergic Synaptic Transmission in Zebrafish Motility Mutants

Science.gov (United States)

Hirata, Hiromi; Carta, Eloisa; Yamanaka, Iori; Harvey, Robert J.; Kuwada, John Y.

2009-01-01

Glycine is a major inhibitory neurotransmitter in the spinal cord and brainstem. Recently, in vivo analysis of glycinergic synaptic transmission has been pursued in zebrafish using molecular genetics. An ENU mutagenesis screen identified two behavioral mutants that are defective in glycinergic synaptic transmission. Zebrafish bandoneon (beo) mutants have a defect in glrbb, one of the duplicated glycine receptor (GlyR) β subunit genes. These mutants exhibit a loss of glycinergic synaptic transmission due to a lack of synaptic aggregation of GlyRs. Due to the consequent loss of reciprocal inhibition of motor circuits between the two sides of the spinal cord, motor neurons activate simultaneously on both sides resulting in bilateral contraction of axial muscles of beo mutants, eliciting the so-called ‘accordion’ phenotype. Similar defects in GlyR subunit genes have been observed in several mammals and are the basis for human hyperekplexia/startle disease. By contrast, zebrafish shocked (sho) mutants have a defect in slc6a9, encoding GlyT1, a glycine transporter that is expressed by astroglial cells surrounding the glycinergic synapse in the hindbrain and spinal cord. GlyT1 mediates rapid uptake of glycine from the synaptic cleft, terminating synaptic transmission. In zebrafish sho mutants, there appears to be elevated extracellular glycine resulting in persistent inhibition of postsynaptic neurons and subsequent reduced motility, causing the ‘twitch-once’ phenotype. We review current knowledge regarding zebrafish ‘accordion’ and ‘twitch-once’ mutants, including beo and sho, and report the identification of a new α2 subunit that revises the phylogeny of zebrafish GlyRs. PMID:20161699

Ciliopathies: Genetics in Pediatric Medicine.

Science.gov (United States)

Oud, Machteld M; Lamers, Ideke J C; Arts, Heleen H

2017-03-01

Ciliary disorders , which are also referred to as ciliopathies , are a group of hereditary disorders that result from dysfunctional cilia. The latter are cellular organelles that stick up from the apical plasma membrane. Cilia have important roles in signal transduction and facilitate communications between cells and their surroundings. Ciliary disruption can result in a wide variety of clinically and genetically heterogeneous disorders with overlapping phenotypes. Because cilia occur widespread in our bodies many organs and sensory systems can be affected when they are dysfunctional. Ciliary disorders may be isolated or syndromic, and common features are cystic liver and/or kidney disease, blindness, neural tube defects, brain anomalies and intellectual disability, skeletal abnormalities ranging from polydactyly to abnormally short ribs and limbs, ectodermal defects, obesity, situs inversus , infertility, and recurrent respiratory tract infections. In this review, we summarize the features, frequency, morbidity, and mortality of each of the different ciliopathies that occur in pediatrics. The importance of genetics and the occurrence of genotype-phenotype correlations are indicated, and advances in gene identification are discussed. The use of next-generation sequencing by which a gene panel or all genes can be screened in a single experiment is highlighted as this technology significantly lowered costs and time of the mutation detection process in the past. We discuss the challenges of this new technology and briefly touch upon the use of whole-exome sequencing as a diagnostic test for ciliary disorders. Finally, a perspective on the future of genetics in the context of ciliary disorders is provided.

[Advance in the methods of preimplantation genetic diagnosis for single gene diseases].

Science.gov (United States)

Ren, Yixin; Qiao, Jie; Yan, Liying

2017-06-10

More than 7000 single gene diseases have been identified and most of them lack effective treatment. As an early form of prenatal diagnosis, preimplantation genetic diagnosis (PGD) is a combination of in vitro fertilization and genetic diagnosis. PGD has been applied in clinics for more than 20 years to avoid the transmission of genetic defects through analysis of embryos at early stages of development. In this paper, a review for the recent advances in PGD for single gene diseases is provided.

Synthetic Genetic Targeting of Genome Instability in Cancer

International Nuclear Information System (INIS)

Sajesh, Babu V.; Guppy, Brent J.; McManus, Kirk J.

2013-01-01

Cancer is a leading cause of death throughout the World. A limitation of many current chemotherapeutic approaches is that their cytotoxic effects are not restricted to cancer cells, and adverse side effects can occur within normal tissues. Consequently, novel strategies are urgently needed to better target cancer cells. As we approach the era of personalized medicine, targeting the specific molecular defect(s) within a given patient’s tumor will become a more effective treatment strategy than traditional approaches that often target a given cancer type or sub-type. Synthetic genetic interactions are now being examined for their therapeutic potential and are designed to target the specific genetic and epigenetic phenomena associated with tumor formation, and thus are predicted to be highly selective. In general, two complementary approaches have been employed, including synthetic lethality and synthetic dosage lethality, to target aberrant expression and/or function associated with tumor suppressor genes and oncogenes, respectively. Here we discuss the concepts of synthetic lethality and synthetic dosage lethality, and explain three general experimental approaches designed to identify novel genetic interactors. We present examples and discuss the merits and caveats of each approach. Finally, we provide insight into the subsequent pre-clinical work required to validate novel candidate drug targets

Genetics of Gigantism and Acromegaly

Science.gov (United States)

Hannah-Shmouni, Fady; Trivellin, Giampaolo; Stratakis, Constantine A.

2016-01-01

Gigantism and acromegaly are rare disorders that are caused by excessive GH secretion and/or high levels of its mediator, IGF-1. Gigantism occurs when excess GH or IGF-1 lead to increased linear growth, before the end of puberty and epiphyseal closure. The majority of cases arise from a benign GH-secreting pituitary adenoma, with an incidence of pituitary gigantism and acromegaly of approximately 8 and 11 per million person-years, respectively. Over the past two decades, our increasing understanding of the molecular and genetic etiologies of pituitary gigantism and acromegaly yielded several genetic causes, including multiple endocrine neoplasia type 1 and 4, McCune-Albright syndrome, Carney complex, familial isolated pituitary adenoma, pituitary adenoma association due to defects in familial succinate dehydrogenase genes, and the recently identified X-linked acrogigantism. The early diagnosis of these conditions helps guide early intervention, screening, and genetic counseling of patients and their family members. In this review, we provide a concise and up-to-date discussion on the genetics of gigantism and acromegaly. PMID:27657986

Genetics of gigantism and acromegaly.

Science.gov (United States)

Hannah-Shmouni, Fady; Trivellin, Giampaolo; Stratakis, Constantine A

Gigantism and acromegaly are rare disorders that are caused by excessive GH secretion and/or high levels of its mediator, IGF-1. Gigantism occurs when excess GH or IGF-1 lead to increased linear growth, before the end of puberty and epiphyseal closure. The majority of cases arise from a benign GH-secreting pituitary adenoma, with an incidence of pituitary gigantism and acromegaly of approximately 8 and 11 per million person-years, respectively. Over the past two decades, our increasing understanding of the molecular and genetic etiologies of pituitary gigantism and acromegaly yielded several genetic causes, including multiple endocrine neoplasia type 1 and 4, McCune-Albright syndrome, Carney complex, familial isolated pituitary adenoma, pituitary adenoma association due to defects in familial succinate dehydrogenase genes, and the recently identified X-linked acrogigantism. The early diagnosis of these conditions helps guide early intervention, screening, and genetic counseling of patients and their family members. In this review, we provide a concise and up-to-date discussion on the genetics of gigantism and acromegaly. Published by Elsevier Ltd.

Family-based analysis of genetic variation underlying psychosis-inducing effects of cannabis : Sibling analysis and proband follow-up

NARCIS (Netherlands)

van Winkel, Ruud; Wiersma, Durk

Context: Individual differences exist in sensitivity to the psychotomimetic effect of cannabis; the molecular genetic basis underlying differential sensitivity remains elusive. Objective: To investigate whether selected schizophrenia candidate single-nucleotide polymorphisms (SNPs) moderate effects

Combining DFT, Cluster Expansions, and KMC to Model Point Defects in Alloys

Science.gov (United States)

Modine, N. A.; Wright, A. F.; Lee, S. R.; Foiles, S. M.; Battaile, C. C.; Thomas, J. C.; van der Ven, A.

In an alloy, defect energies are sensitive to the occupations of nearby atomic sites, which leads to a distribution of defect properties. When radiation-induced defects diffuse from their initially non-equilibrium locations, this distribution becomes time-dependent. The defects can become trapped in energetically favorable regions of the alloy leading to a diffusion rate that slows dramatically with time. Density Functional Theory (DFT) allows the accurate determination of ground state and transition state energies for a defect in a particular alloy environment but requires thousands of processing hours for each such calculation. Kinetic Monte-Carlo (KMC) can be used to model defect diffusion and the changing distribution of defect properties but requires energy evaluations for millions of local environments. We have used the Cluster Expansion (CE) formalism to ``glue'' together these seemingly incompatible methods. The occupation of each alloy site is represented by an Ising-like variable, and products of these variables are used to expand quantities of interest. Once a CE is fit to a training set of DFT energies, it allows very rapid evaluation of the energy for an arbitrary configuration, while maintaining the accuracy of the underlying DFT calculations. These energy evaluations are then used to drive our KMC simulations. We will demonstrate the application of our DFT/MC/KMC approach to model thermal and carrier-induced diffusion of intrinsic point defects in III-V alloys. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE.

Genetic variations in ARE1 mediate grain yield by modulating nitrogen utilization in rice.

Science.gov (United States)

Wang, Qing; Nian, Jinqiang; Xie, Xianzhi; Yu, Hong; Zhang, Jian; Bai, Jiaoteng; Dong, Guojun; Hu, Jiang; Bai, Bo; Chen, Lichao; Xie, Qingjun; Feng, Jian; Yang, Xiaolu; Peng, Juli; Chen, Fan; Qian, Qian; Li, Jiayang; Zuo, Jianru

2018-02-21

In crops, nitrogen directly determines productivity and biomass. However, the improvement of nitrogen utilization efficiency (NUE) is still a major challenge in modern agriculture. Here, we report the characterization of are1, a genetic suppressor of a rice fd-gogat mutant defective in nitrogen assimilation. ARE1 is a highly conserved gene, encoding a chloroplast-localized protein. Loss-of-function mutations in ARE1 cause delayed senescence and result in 10-20% grain yield increases, hence enhance NUE under nitrogen-limiting conditions. Analysis of a panel of 2155 rice varieties reveals that 18% indica and 48% aus accessions carry small insertions in the ARE1 promoter, which result in a reduction in ARE1 expression and an increase in grain yield under nitrogen-limiting conditions. We propose that ARE1 is a key mediator of NUE and represents a promising target for breeding high-yield cultivars under nitrogen-limiting condition.

Melanoma genetics

DEFF Research Database (Denmark)

Read, Jazlyn; Wadt, Karin A W; Hayward, Nicholas K

2015-01-01

Approximately 10% of melanoma cases report a relative affected with melanoma, and a positive family history is associated with an increased risk of developing melanoma. Although the majority of genetic alterations associated with melanoma development are somatic, the underlying presence of herita......Approximately 10% of melanoma cases report a relative affected with melanoma, and a positive family history is associated with an increased risk of developing melanoma. Although the majority of genetic alterations associated with melanoma development are somatic, the underlying presence...... in a combined total of approximately 50% of familial melanoma cases, the underlying genetic basis is unexplained for the remainder of high-density melanoma families. Aside from the possibility of extremely rare mutations in a few additional high penetrance genes yet to be discovered, this suggests a likely...... polygenic component to susceptibility, and a unique level of personal melanoma risk influenced by multiple low-risk alleles and genetic modifiers. In addition to conferring a risk of cutaneous melanoma, some 'melanoma' predisposition genes have been linked to other cancers, with cancer clustering observed...

The genetic effects of the atomic bombs

International Nuclear Information System (INIS)

Neel, J.V.

1992-01-01

Studies on the genetic effects of the atomic bombs detonated over Hiroshima and Nagasaki have been in progress since 1946. The indicators of potential genetic damage in the children of exposees which have been employed are: (1) untoward pregnancy outcomes (major congenital defect and/or stillbirth and/or neonatal death), (2) death of liveborn infants prior to average age 28.8 years, (3) cancer of onset prior to age 20, (4) sex chromosome aneuploidy, (5) mutations affecting protein electrophoretic mobility and/or activity, (6) chromosomal reciprocal translocations, (7) sex-ratio in the children of exposed mothers, and (8) physical development at birth, at 9-months, and at school age. There is no statistically significant effect of parental exposure to the bombs on any of these indicators. The net regression of indicator(s) on dose is, however, positive. On the basis of these regressions and assumptions concerning the contribution of spontaneous mutation to the indicator values in the controls, the gametic doubling dose of acute ionizing radiation under these circumstances is estimated to be 2 Sv. With a dose rate factor of 2, which seems appropriate to these circumstances, the doubling dose for chronic radiation is placed at 4 Sv. This is a substantially higher estimate than previous extrapolations to man from murine experiments

Blaschko Linear Enamel Defects - A Marker for Focal Dermal Hypoplasia: Case Report of Focal Dermal Hypoplasia

Directory of Open Access Journals (Sweden)

Stefan Gysin

2015-05-01

Full Text Available Focal dermal hypoplasia (FDH is a rare genetic skin disorder. The inheritance of FDH or Goltz-Gorlin syndrome is X-linked dominant and the disease is associated with a PORCN gene mutation. This gene plays a key role in the Wnt pathway, which has an impact on embryonic development. Every tissue derived from meso- and ectoderm can be affected. Patients suffer from cutaneous, ocular, osseous, oral and dental defects. The skin and dental alterations manifest along the Blaschko lines. We present a woman (born in 1962 suffering from FDH with congenital skin changes and Blaschko linear enamel defects. Typical symptoms (e.g. fat herniations, scoliosis, syndactyly, microphthalmia, caries and alopecia plus vertical grooving of all teeth gave a first indication. Molecular genetic testing confirmed the definitive diagnosis of FDH. We hypothesize that, in the context of typical skin changes, visible Blaschko lines on the teeth in the form of vertical grooves are almost pathognomonic for FDH.

Activation of multiple signaling pathways causes developmental defects in mice with a Noonan syndrome–associated Sos1 mutation

Science.gov (United States)

Chen, Peng-Chieh; Wakimoto, Hiroko; Conner, David; Araki, Toshiyuki; Yuan, Tao; Roberts, Amy; Seidman, Christine E.; Bronson, Roderick; Neel, Benjamin G.; Seidman, Jonathan G.; Kucherlapati, Raju

2010-01-01

Noonan syndrome (NS) is an autosomal dominant genetic disorder characterized by short stature, unique facial features, and congenital heart disease. About 10%–15% of individuals with NS have mutations in son of sevenless 1 (SOS1), which encodes a RAS and RAC guanine nucleotide exchange factor (GEF). To understand the role of SOS1 in the pathogenesis of NS, we generated mice with the NS-associated Sos1E846K gain-of-function mutation. Both heterozygous and homozygous mutant mice showed many NS-associated phenotypes, including growth delay, distinctive facial dysmorphia, hematologic abnormalities, and cardiac defects. We found that the Ras/MAPK pathway as well as Rac and Stat3 were activated in the mutant hearts. These data provide in vivo molecular and cellular evidence that Sos1 is a GEF for Rac under physiological conditions and suggest that Rac and Stat3 activation might contribute to NS phenotypes. Furthermore, prenatal administration of a MEK inhibitor ameliorated the embryonic lethality, cardiac defects, and NS features of the homozygous mutant mice, demonstrating that this signaling pathway might represent a promising therapeutic target for NS. PMID:21041952

WMAP constraints on inflationary models with global defects

International Nuclear Information System (INIS)

Bevis, Neil; Hindmarsh, Mark; Kunz, Martin

2004-01-01

We use the cosmic microwave background angular power spectra to place upper limits on the degree to which global defects may have aided cosmic structure formation. We explore this under the inflationary paradigm, but with the addition of textures resulting from the breaking of a global O(4) symmetry during the early stages of the Universe. As a measure of their contribution, we use the fraction of the temperature power spectrum that is attributed to the defects at a multipole of 10. However, we find a parameter degeneracy enabling a fit to the first-year WMAP data to be made even with a significant defect fraction. This degeneracy involves the baryon fraction and the Hubble constant, plus the normalization and tilt of the primordial power spectrum. Hence, constraints on these cosmological parameters are weakened. Combining the WMAP data with a constraint on the physical baryon fraction from big bang nucleosynthesis calculations and high-redshift deuterium abundance limits the extent of the degeneracy and gives an upper bound on the defect fraction of 0.13 (95% confidence)

Family-Based Analysis of Genetic Variation Underlying Psychosis-Inducing Effects of Cannabis: Sibling Analysis and Proband Follow-up

NARCIS (Netherlands)

van Winkel, Ruud; Kahn, René S.; Linszen, Don H.; van Os, Jim; Wiersma, Durk; Bruggeman, Richard; Cahn, Wiepke; de Haan, Lieuwe; Krabbendam, Lydia; Myin-Germeys, Inez

2011-01-01

Individual differences exist in sensitivity to the psychotomimetic effect of cannabis; the molecular genetic basis underlying differential sensitivity remains elusive. To investigate whether selected schizophrenia candidate single-nucleotide polymorphisms (SNPs) moderate effects of cannabis use.

Production behavior of irradiation defects in solid breeder materials

Energy Technology Data Exchange (ETDEWEB)

Moriyama, Hirotake; Moritani, Kimikazu [Kyoto Univ. (Japan)

1998-03-01

The irradiation effects in solid breeder materials are important for the performance assessment of fusion reactor blanket systems. For a clearer understanding of such effects, we have studied the production behavior of irradiation defects in some lithium ceramics by an in-situ luminescence measurement technique under ion beam irradiation. The luminescence spectra were measured at different temperatures, and the temperature-transient behaviors of luminescence intensity were also measured. The production mechanisms of irradiation defects were discussed on the basis of the observations. (author)

Preimplantation genetic diagnosis and rational choice under risk or uncertainty.

Science.gov (United States)

Zuradzki, Tomasz

2014-11-01

In this paper I present an argument in favour of a parental duty to use preimplantation genetic diagnosis (PGD). I argue that if embryos created in vitro were able to decide for themselves in a rational manner, they would sometimes choose PGD as a method of selection. Couples, therefore, should respect their hypothetical choices on a principle similar to that of patient autonomy. My thesis shows that no matter which moral doctrine couples subscribe to, they ought to conduct the PGD procedure in the situations when it is impossible to implant all of the created embryos and if there is a significant risk for giving birth to a child with a serious condition. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Defects in copper studied by PAC between 10 K and 800 K

International Nuclear Information System (INIS)

Deicher, M.; Gruebel, G.; Minde, R.; Recknagel, E.; Wichert, Th.

1982-01-01

The perturbed angular correlation technique (PAC) is used to clarify the defect situation in copper between stage I and V. The experimental results obtained for selfinterstitials, vacancies and defect clusters under different damaging conditions are shown. Their microscopic interpretation within the scope of the results of complementary experimental methods is discussed. (author)

New developments on the neurobiological and pharmaco-genetic mechanisms underlying internet and videogame addiction.

Science.gov (United States)

Weinstein, Aviv; Lejoyeux, Michel

2015-03-01

There is emerging evidence that the psychobiological mechanisms underlying behavioral addictions such as internet and videogame addiction resemble those of addiction for substances of abuse. Review of brain imaging, treatment and genetic studies on videogame and internet addiction. Literature search of published articles between 2009 and 2013 in Pubmed using "internet addiction" and "videogame addiction" as the search word. Twenty-nine studies have been selected and evaluated under the criteria of brain imaging, treatment, and genetics. Brain imaging studies of the resting state have shown that long-term internet game playing affected brain regions responsible for reward, impulse control and sensory-motor coordination. Brain activation studies have shown that videogame playing involved changes in reward and loss of control and that gaming pictures have activated regions similarly to those activated by cue-exposure to drugs. Structural studies have shown alterations in the volume of the ventral striatum possible as result of changes in reward. Furthermore, videogame playing was associated with dopamine release similar in magnitude to those of drugs of abuse and that there were faulty inhibitory control and reward mechanisms videogame addicted individuals. Finally, treatment studies using fMRI have shown reduction in craving for videogames and reduced associated brain activity. Videogame playing may be supported by similar neural mechanisms underlying drug abuse. Similar to drug and alcohol abuse, internet addiction results in sub-sensitivity of dopamine reward mechanisms. Given the fact that this research is in its early stage it is premature to conclude that internet addiction is equivalent to substance addictions. © American Academy of Addiction Psychiatry.

Intrinsic and defect related luminescence in double oxide films of Al–Hf–O system under soft X-ray and VUV excitation

Energy Technology Data Exchange (ETDEWEB)

Pustovarov, V.A., E-mail: vpustovarov@bk.ru [Ural Federal University, 19 Mira Street, 620002 Yekaterinburg (Russian Federation); Smirnova, T.P.; Lebedev, M.S. [Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Science, Novosibirsk 630090 (Russian Federation); Gritsenko, V.A. [Institute of Semiconductor Physics, Siberian Branch of Russian Academy of Sciences, Novosibirsk 630090 (Russian Federation); Novosibirsk National Research University, 2 Pirogova Street, 630090 Novosibirsk (Russian Federation); Kirm, M. [Institute of Physics, University of Tartu, 14c Ravila, 50411 Tartu (Estonia)

2016-02-15

Low temperature time-resolved luminescence spectra in the region of 2.5–9.5 eV under soft X-ray excitation as well as time-resolved luminescence excitation spectra in the UV–VUV region (3.7–12 eV) of solid solutions Al{sub x}Hf{sub y}O{sub 1−x−y} thin films were investigated. The values of x and Al/Hf ratio were determined from X-ray photoelectron srectroscopy data. Hafnia films and films mixed with alumina were grown in a flow-type chemical vapor deposition reactor with argon as a carrier gas. In addition, pure alumina films were prepared by the atomic layer deposition method. A strong emission band with the peak position at 4.4 eV and with the decay time in the μs-range was revealed for pure hafnia films. The emission peak at 7.74 eV with short nanosecond decay kinetics was observed in the luminescence spectra for pure alumina films. These emission bands were ascribed to the radiative decay of self-trapped excitons (an intrinsic luminescence) in pure HfO{sub 2} and Al{sub 2}O{sub 3} films, respectively. Along with intrinsic host emission, defect related luminescence bands with a larger Stokes shift were observed. In the emission spectra of the solid solution films (x=4; 17; 20 at%) the intrinsic emission bands are quenched and only the luminescence of defects (an anion vacancies) was observed. Based on transformation of the luminescence spectra and ns-luminescence decay kinetics, as well as changes in the time-resolved luminescence and luminescence excitation spectra, the relaxation processes in the films of solid solution are discussed. - Highlights: • Low temperature time−resolved PL spectra were studied in a broad range (1.5−9.5 eV). • We carried out a luminescent control of point defects (anion vacancies) and self−trapped excitons. • We observed photoluminescence of excitons bound on defects. • We observed changes of photoluminescence properties with varying ratio components.

Ribosomal and hematopoietic defects in induced pluripotent stem cells derived from Diamond Blackfan anemia patients.

Science.gov (United States)

Garçon, Loïc; Ge, Jingping; Manjunath, Shwetha H; Mills, Jason A; Apicella, Marisa; Parikh, Shefali; Sullivan, Lisa M; Podsakoff, Gregory M; Gadue, Paul; French, Deborah L; Mason, Philip J; Bessler, Monica; Weiss, Mitchell J

2013-08-08

Diamond Blackfan anemia (DBA) is a congenital disorder with erythroid (Ery) hypoplasia and tissue morphogenic abnormalities. Most DBA cases are caused by heterozygous null mutations in genes encoding ribosomal proteins. Understanding how haploinsufficiency of these ubiquitous proteins causes DBA is hampered by limited availability of tissues from affected patients. We generated induced pluripotent stem cells (iPSCs) from fibroblasts of DBA patients carrying mutations in RPS19 and RPL5. Compared with controls, DBA fibroblasts formed iPSCs inefficiently, although we obtained 1 stable clone from each fibroblast line. RPS19-mutated iPSCs exhibited defects in 40S (small) ribosomal subunit assembly and production of 18S ribosomal RNA (rRNA). Upon induced differentiation, the mutant clone exhibited globally impaired hematopoiesis, with the Ery lineage affected most profoundly. RPL5-mutated iPSCs exhibited defective 60S (large) ribosomal subunit assembly, accumulation of 12S pre-rRNA, and impaired erythropoiesis. In both mutant iPSC lines, genetic correction of ribosomal protein deficiency via complementary DNA transfer into the "safe harbor" AAVS1 locus alleviated abnormalities in ribosome biogenesis and hematopoiesis. Our studies show that pathological features of DBA are recapitulated by iPSCs, provide a renewable source of cells to model various tissue defects, and demonstrate proof of principle for genetic correction strategies in patient stem cells.

A study of defects in diamond

International Nuclear Information System (INIS)

Hunt, D.C.

1999-01-01

Defects, intrinsic and extrinsic, in natural and synthetic diamond, have been studied using Electron Paramagnetic Resonance (EPR) and optical absorption techniques. EPR measurements have been used in conjunction with infrared absorption to identify the defect-induced one-phonon infrared spectra produced by ionised single substitutional nitrogen, N s + . This N s + spectrum is characterised by a sharp peak at the Raman energy, 1332 cm -1 , accompanied by several broader resonances at 950(5), 1050(5), and 1095(5) cm -1 . Detailed concentration measurements show that a concentration of 5.5(5) ppm gives rise to an absorption of 1 cm -1 at 1332 cm -1 . The optical absorption band ND1, identified as the negative vacancy (V - ), is frequently used by diamond spectroscopists to measure the concentration of V - . Isoya has identified V - in the EPR spectra of irradiated diamond. The accuracy of EPR in determining concentrations, has been used to correlate the integrated absorption of the ND1 zero-phonon line to the concentration of V - centres. The parameter derived from this correlation is ∼16 times smaller than the previously accepted value obtained by indirect methods. A systematic study has been made - using EPR and optical absorption techniques - of synthetic type IIa diamonds, which have been irradiated with 2 MeV electrons in a specially developed dewar, allowing irradiation down to a measured sample temperature of 100K. Measurement of defect creation rates of the neutral vacancy and EPR defects, show a radical difference in the production rate of the EPR defect R2 between irradiation with the sample held at 100K and 350K. At 100K its production rate is 1.1(1) cm -1 , ∼10 times greater that at 350K. Observation of the di- -split interstitial (Ri) after irradiation at 100K proves the self-interstitial in diamond must be mobile at 100K, under the conditions of irradiation. Further study of the properties of the R2 defect (the most dominant EPR after electron

Genetic mutations associated with status epilepticus.

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Bhatnagar, M; Shorvon, S

2015-08-01

This paper reports the results of a preliminary search of the literature aimed at identifying the genetic mutations reported to be strongly associated with status epilepticus. Genetic mutations were selected for inclusion if status epilepticus was specifically mentioned as a consequence of the mutation in standard genetic databases or in a case report or review article. Mutations in 122 genes were identified. The genetic mutations identified were found in only rare conditions (sometimes vanishingly rare) and mostly in infants and young children with multiple other handicaps. Most of the genetic mutations can be subdivided into those associated with cortical dysplasias, inborn errors of metabolism, mitochondrial disease, or epileptic encephalopathies and childhood syndromes. There are no identified 'pure status epilepticus genes'. The range of genes underpinning status epilepticus differs in many ways from the range of genes underpinning epilepsy, which suggests that the processes underpinning status epilepticus differ from those underpinning epilepsy. It has been frequently postulated that status epilepticus is the result of a failure of 'seizure termination mechanisms', but the wide variety of genes affecting very diverse biochemical pathways identified in this survey makes any unitary cause unlikely. The genetic influences in status epilepticus are likely to involve a wide range of mechanisms, some related to development, some to cerebral energy production, some to diverse altered biochemical pathways, some to transmitter and membrane function, and some to defects in networks or systems. The fact that many of the identified genes are involved with cerebral development suggests that status epilepticus might often be a system or network phenomenon. To date, there are very few genes identified which are associated with adult-onset status epilepticus (except in those with preexisting neurological damage), and this is disappointing as the cause of many adult

Active magnetic bearings used as exciters for rolling element bearing outer race defect diagnosis.

Science.gov (United States)

Xu, Yuanping; Di, Long; Zhou, Jin; Jin, Chaowu; Guo, Qintao

2016-03-01

The active health monitoring of rotordynamic systems in the presence of bearing outer race defect is considered in this paper. The shaft is assumed to be supported by conventional mechanical bearings and an active magnetic bearing (AMB) is used in the mid of the shaft location as an exciter to apply electromagnetic force to the system. We investigate a nonlinear bearing-pedestal system model with the outer race defect under the electromagnetic force. The nonlinear differential equations are integrated using the fourth-order Runge-Kutta algorithm. The simulation and experimental results show that the characteristic signal of outer race incipient defect is significantly amplified under the electromagnetic force through the AMBs, which is helpful to improve the diagnosis accuracy of rolling element bearing׳s incipient outer race defect. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Biochemical and genetic diagnosis of Smith-Lemli- Opitz syndrome ...

African Journals Online (AJOL)

The clinical spectrum of manifestations is broad, ... delay as well as selfinjurious behaviour and autism are reported. ... recessive disorder that is more common than other defects in cholesterol biosynthesis. ... To perform biochemical and genetic workups in four South African families of European ancestry with suspected ...

Point defects in thorium nitride: A first-principles study

Energy Technology Data Exchange (ETDEWEB)

Pérez Daroca, D., E-mail: pdaroca@tandar.cnea.gov.ar [Gerencia de Investigación y Aplicaciones, Comisión Nacional de Energía Atómica (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas (Argentina); Llois, A.M. [Gerencia de Investigación y Aplicaciones, Comisión Nacional de Energía Atómica (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas (Argentina); Mosca, H.O. [Gerencia de Investigación y Aplicaciones, Comisión Nacional de Energía Atómica (Argentina); Instituto de Tecnología Jorge A. Sabato, UNSAM-CNEA (Argentina)

2016-11-15

Thorium and its compounds (carbides and nitrides) are being investigated as possible materials to be used as nuclear fuels for Generation-IV reactors. As a first step in the research of these materials under irradiation, we study the formation energies and stability of point defects in thorium nitride by means of first-principles calculations within the framework of density functional theory. We focus on vacancies, interstitials, Frenkel pairs and Schottky defects. We found that N and Th vacancies have almost the same formation energy and that the most energetically favorable defects of all studied in this work are N interstitials. These kind of results for ThN, to the best authors' knowledge, have not been obtained previously, neither experimentally, nor theoretically.

Point defects in thorium nitride: A first-principles study

International Nuclear Information System (INIS)

Pérez Daroca, D.; Llois, A.M.; Mosca, H.O.

2016-01-01

Thorium and its compounds (carbides and nitrides) are being investigated as possible materials to be used as nuclear fuels for Generation-IV reactors. As a first step in the research of these materials under irradiation, we study the formation energies and stability of point defects in thorium nitride by means of first-principles calculations within the framework of density functional theory. We focus on vacancies, interstitials, Frenkel pairs and Schottky defects. We found that N and Th vacancies have almost the same formation energy and that the most energetically favorable defects of all studied in this work are N interstitials. These kind of results for ThN, to the best authors' knowledge, have not been obtained previously, neither experimentally, nor theoretically.

Researcher responsibilities and genetic counseling for pure-bred dog populations.

Science.gov (United States)

Bell, Jerold S

2011-08-01

Breeders of dogs have ethical responsibilities regarding the testing and management of genetic disease. Molecular genetics researchers have their own responsibilities, highlighted in this article. Laboratories offering commercial genetic testing should have proper sample identification and quality control, official test result certificates, clear explanations of test results and reasonably priced testing fees. Providing test results to a publicly-accessible genetic health registry allows breeders and the public to search for health-tested parents to reduce the risk of producing or purchasing affected offspring. Counseling on the testing and elimination of defective genes must consider the effects of genetic selection on the population. Recommendations to breed quality carriers to normal-testing dogs and replacing them with quality normal-testing offspring will help to preserve breeding lines and breed genetic diversity. Copyright © 2011 Elsevier Ltd. All rights reserved.

Electronic structure of point defects in semiconductors

International Nuclear Information System (INIS)

Bruneval, Fabien

2014-01-01

This 'Habilitation a diriger des Recherches' memoir presents most of my scientific activities during the past 7 years, in the field of electronic structure calculations of defects in solids. Point defects (vacancies, interstitials, impurities) in functional materials are a key parameter to determine if these materials will actually fill the role they have been assigned or not. Indeed, the presence of defects cannot be avoided when the temperature is increased or when the material is subjected to external stresses, such as irradiation in the nuclear reactors and in artificial satellites with solar radiations. However, in many cases, defects are introduced in the materials on purpose to tune the electronic transport, optical or even magnetic properties. This procedure is called the doping of semiconductors, which is the foundation technique for transistors, diodes, or photovoltaic cells. However, doping is not always straightforward and unexpected features may occur, such as doping asymmetry or Fermi level pinning, which can only be explained by complex phenomena involving different types of defects or complexes of defects. In this context, the calculations of electronic structure ab initio is an ideal tool to complement the experimental observations, to gain the understanding of phenomena at the atomic level, and even to predict the properties of defects. The power of the ab initio calculations comes from their ability to describe any system of electrons and nuclei without any specific adjustment. But although there is a strong need for numerical simulations in this field, the ab initio calculations for defects are still under development as of today. The work presented in this memoir summarizes my contributions to methodological developments on this subject. These developments have followed two main tracks. The first topic is the better understanding of the unavoidable finite size effects. Indeed, defects in semiconductors or insulators are generally present in

Defects in semiconductors

CERN Document Server

Romano, Lucia; Jagadish, Chennupati

2015-01-01

This volume, number 91 in the Semiconductor and Semimetals series, focuses on defects in semiconductors. Defects in semiconductors help to explain several phenomena, from diffusion to getter, and to draw theories on materials' behavior in response to electrical or mechanical fields. The volume includes chapters focusing specifically on electron and proton irradiation of silicon, point defects in zinc oxide and gallium nitride, ion implantation defects and shallow junctions in silicon and germanium, and much more. It will help support students and scientists in their experimental and theoret

[Unaffected child born following preimplantation genetic diagnosis with karyomapping].

Science.gov (United States)

Nánássy, László; Téglás, Gyöngyvér; Csenki, Marianna; Vereczkey, Attila

2016-12-01

Preimplantation genetic diagnosis for single gene defects is a well established method in assisted reproductive technologies. Karyomapping is a genome wide parental haplotyping using a high density single nucleotide polymorphism array that allows the diagnosis of any single gene defects. A couple with an affected child with primary congenital glaucoma attended at our clinic. Six oocyte-cumulus-complex was retrieved and all three mature oocytes were inseminated. One zygote showed the signs of normal fertilization and was cultured for five days. Trophectoderm biopsy and karyomapping analysis were carried out. Result showed a heterozygous carrier for primary congenital glaucoma. Embryo was thawed and transferred and a healthy girl was delivered at term. Here we report the first live birth following in vitro fertilization combined with preimplantation genetic diagnosis using karyomapping in Hungary. Karyomapping is able to accurately detect single gene disorders from a limited amount of samples without a significant preclinical workup. Orv. Hetil., 2016, 157(51), 2048-2050.

Defect phase diagram for doping of Ga2O3

Science.gov (United States)

Lany, Stephan

2018-04-01

For the case of n-type doping of β-Ga2O3 by group 14 dopants (C, Si, Ge, Sn), a defect phase diagram is constructed from defect equilibria calculated over a range of temperatures (T), O partial pressures (pO2), and dopant concentrations. The underlying defect levels and formation energies are determined from first-principles supercell calculations with GW bandgap corrections. Only Si is found to be a truly shallow donor, C is a deep DX-like (lattice relaxed donor) center, and Ge and Sn have defect levels close to the conduction band minimum. The thermodynamic modeling includes the effect of association of dopant-defect pairs and complexes, which causes the net doping to decline when exceeding a certain optimal dopant concentration. The optimal doping levels are surprisingly low, between about 0.01% and 1% of cation substitution, depending on the (T, pO2) conditions. Considering further the stability constraints due to sublimation of molecular Ga2O, specific predictions of optimized pO2 and Si dopant concentrations are given. The incomplete passivation of dopant-defect complexes in β-Ga2O3 suggests a design rule for metastable doping above the solubility limit.

UCN anomalous losses and the UCN capture cross section on material defects

International Nuclear Information System (INIS)

Serebrov, A.; Romanenko, N.; Zherebtsov, O.; Lasakov, M.; Vasiliev, A.; Fomin, A.; Geltenbort, P.; Krasnoshekova, I.; Kharitonov, A.; Varlamov, V.

2005-01-01

Experimental data shows anomalously large ultra cold neutrons (UCN) reflection losses and that the process of UCN reflection is not completely coherent. UCN anomalous losses under reflection cannot be explained in the context of neutron optics calculations. UCN losses by means of incoherent scattering on material defects are considered and cross-section values calculated. The UCN capture cross section on material defects is enhanced by a factor of 10 4 due to localization of UCN around defects. This phenomenon can explain anomalous losses of UCN

Intraspecific Variation in Pines from the Trans-Mexican Volcanic Belt Grown under Two Watering Regimes: Implications for Management of Genetic Resources

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Andrés Flores

2018-01-01

Full Text Available Management of forest genetic resources requires experimental data related to the genetic variation of the species and populations under different climatic conditions. Foresters also demand to know how the main selective drivers will influence the adaptability of the genetic resources. To assess the inter- and intraspecific variation and plasticity in seedling drought tolerance at a relevant genetic resource management scale, we tested the changes in growth and biomass allocation of seedlings of Pinus oocarpa, P. patula and P. pseudostrobus under two contrasting watering regimes. We found general significant intraspecific variation and intraspecific differences in plasticity, since both population and watering by population interaction were significant for all three species. All the species and populations share a common general avoidance mechanism (allometric adjustment of shoot/root biomass. However, the intraspecific variation and differences in phenotypic plasticity among populations modify the adaptation strategies of the species to drought. Some of the differences are related to the climatic conditions of the location of origin. We confirmed that even at reduced geographical scales, Mexican pines present differences in the response to water stress. The differences among species and populations are relevant in afforestation programs as well as in genetic conservation activities.

Genetic diversity of Siberian stone pine under introduction in the South Urals and Bashkir Cis-Urals

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Z. Kh. Shigapov

2016-10-01

Full Text Available Allozyme polymorphism of Siberian stone pine Pinus sibirica Du Tour has been studied in 14 artificial stands in the South Urals and Bashkir Cis-Urals on the base of 7 gene-enzyme system analysis. The following values of genetic diversity are determined: mean number of alleles per locus (A constitutes 1.69±0.08; portion of polymorphic loci (P95 – 50.0 %; the average expected heterozygosity (He – 0.121±0.015; the average observed heterozygosity (Ho – 0.127±0.017.The level of genetic variability in artificial stands of Siberian stone pine in the region is somewhat inferior to that in natural populations of the species. The highest genotype heterozygosity is determined in high-productive 110 year-old artificial stand in the South Urals (Beloretsky-2 site, and also in Ufimsky and Mishkinsky sites in Bashkir Cis-Urals. The lowest heterozygosity values are revealed in Birsky and Tuimazinsky sites characterized by the weakened vital state of individuals. In total we can speak about the maintenance of essential part of the species’ genetic polymorphism under introduction, especially in some stands. Genetic similarity of the studied stands is shown: inter-sample component of the total genetic diversity (FST constitutes 2.2 %, the average Nei’s genetic distance (D – 0.0033±0.00023, that is also typical of natural populations of Siberian stone pine in the species range. The obtained data about the genetic variability level of artificial stands in a complex with forestry characteristics give evidence of the successful species introduction in the region and the necessity of resumption of works on Siberian stone pine culture establishment in an industrial scale.

The electronic transport properties of defected bilayer sliding armchair graphene nanoribbons

Science.gov (United States)

Mohammadi, Amin; Haji-Nasiri, Saeed

2018-04-01

By applying non-equilibrium Green's functions (NEGF) in combination with tight-binding (TB) model, we investigate and compare the electronic transport properties of perfect and defected bilayer armchair graphene nanoribbons (BAGNRs) under finite bias. Two typical defects which are placed in the middle of top layer (i.e. single vacancy (SV) and stone wale (SW) defects) are examined. The results reveal that in both perfect and defected bilayers, the maximum current refers to β-AB, AA and α-AB stacking orders, respectively, since the intermolecular interactions are stronger in them. Moreover it is observed that a SV decreases the current in all stacking orders, but the effects of a SW defect is nearly unpredictable. Besides, we introduced a sequential switching behavior and the effects of defects on the switching performance is studied as well. We found that a SW defect can significantly improve the switching behavior of a bilayer system. Transmission spectrum, band structure, molecular energy spectrum and molecular projected self-consistent Hamiltonian (MPSH) are analyzed subsequently to understand the electronic transport properties of these bilayer devices which can be used in developing nano-scale bilayer systems.

Inherited DNA repair defects in H. sapiens: their relation to uv-associated processes in xeroderma pigmentosum

International Nuclear Information System (INIS)

Robbins, J.H.; Kraemer, K.H.; Andrews, A.D.

1976-01-01

Xeroderma pigmentosum (XP) is an autosomal recessive disease in which patients develop pigmentation abnormalities and numerous malignancies on areas of skin exposed to sunlight. Some XP patients have neurological abnormalities in addition to their cutaneous pathology. Genetic defects in DNA repair have now been found in all studied XP patients. Here, we shall review and present studies relating the different inherited DNA repair defects of XP to several uv-associated processes. Peripheral blood lymphocytes and skin fibroblasts obtained from patients were cultured and the uv-induced thymidine incorporation in DNA was measured by autoradiography or by scintillation spectroscopy

Configuration of ripple domains and their topological defects formed under local mechanical stress on hexagonal monolayer graphene.

Science.gov (United States)

Park, Yeonggu; Choi, Jin Sik; Choi, Taekjib; Lee, Mi Jung; Jia, Quanxi; Park, Minwoo; Lee, Hoonkyung; Park, Bae Ho

2015-03-24

Ripples in graphene are extensively investigated because they ensure the mechanical stability of two-dimensional graphene and affect its electronic properties. They arise from spontaneous symmetry breaking and are usually manifested in the form of domains with long-range order. It is expected that topological defects accompany a material exhibiting long-range order, whose functionality depends on characteristics of domains and topological defects. However, there remains a lack of understanding regarding ripple domains and their topological defects formed on monolayer graphene. Here we explore configuration of ripple domains and their topological defects in exfoliated monolayer graphenes on SiO2/Si substrates using transverse shear microscope. We observe three-color domains with three different ripple directions, which meet at a core. Furthermore, the closed domain is surrounded by an even number of cores connected together by domain boundaries, similar to topological vortex and anti-vortex pairs. In addition, we have found that axisymmetric three-color domains can be induced around nanoparticles underneath the graphene. This fascinating configuration of ripple domains may result from the intrinsic hexagonal symmetry of two-dimensional graphene, which is supported by theoretical simulation using molecular dynamics. Our findings are expected to play a key role in understanding of ripple physics in graphene and other two-dimensional materials.

Revisiting the reasons for contact fatigue defects in rails

Directory of Open Access Journals (Sweden)

Darenskiy Alexander

2017-01-01

Full Text Available As it is known rail is one of the most significant elements of the whole railway construction. Operation under alternating loads from wheels of the rolling stock and different ambient temperatures lead to appearance and development of rail defects and damages. A great variety of operational factors (freight traffic density, axial loads, traffic speeds, track layout and profile as well as special features of manufacturing and thermal treatment of rails create certain difficulties while identifying reasons for defects and damages. The article deals with an attempt to estimate influence of track layout and lateral forces on appearance of defects and damages in rails on the base of long-term observations of rail operation in Kharkiv Metro. On the basis of the vehicle/track mathematical model which considers structural features of both rolling stock and permanent way in underground systems, the level of lateral forces in curves was calculated. The coefficients of correlation between the track curvature, the level of forces and the amount of defected rails removed were later obtained, that made it possible to determine the dominant factor which may lead to appearance and development of contact fatigue defects in rails laid in curves.

Zirconium - ab initio modelling of point defects diffusion

International Nuclear Information System (INIS)

Gasca, Petrica

2010-01-01

Zirconium is the main element of the cladding found in pressurized water reactors, under an alloy form. Under irradiation, the cladding elongate significantly, phenomena attributed to the vacancy dislocation loops growth in the basal planes of the hexagonal compact structure. The understanding of the atomic scale mechanisms originating this process motivated this work. Using the ab initio atomic modeling technique we studied the structure and mobility of point defects in Zirconium. This led us to find four interstitial point defects with formation energies in an interval of 0.11 eV. The migration paths study allowed the discovery of activation energies, used as entry parameters for a kinetic Monte Carlo code. This code was developed for calculating the diffusion coefficient of the interstitial point defect. Our results suggest a migration parallel to the basal plane twice as fast as one parallel to the c direction, with an activation energy of 0.08 eV, independent of the direction. The vacancy diffusion coefficient, estimated with a two-jump model, is also anisotropic, with a faster process in the basal planes than perpendicular to them. Hydrogen influence on the vacancy dislocation loops nucleation was also studied, due to recent experimental observations of cladding growth acceleration in the presence of this element [fr

A Study of Defect Behavior in Almandine Garnet

Science.gov (United States)

Geiger, C. A.; Brearley, A. J.; Dachs, E.; Tipplet, G.; Rossman, G. R.

2016-12-01

Transport and diffusion in crystals are controlled by defects. However, a good understanding of the defect types in many silicates, including garnet, is not at hand. We undertook a study on synthetic almandine, ideal end-member Fe3Al2Si3O12, to better understand its precise chemical and physical properties and defect behavior. Crystals were synthesized at high pressures and temperatures under different fO2 conditions using various starting materials with H2O and without. The almandine obtained came in polycrystalline and single-crystal form. The synthetic reaction products and crystals were carefully characterized using X-ray powder diffraction, electron microprobe and TEM analysis and with 57Fe Mössbauer, UV/VIS single-crystal absorption and IR single-crystal spectroscopy. Various possible intrinsic defects, such as the Frenkel, Schottky and site-disorder types, along with Fe3+, in both synthetic and natural almandine crystals, were analyzed based on model defects expressed in Kröger-Vink notation. Certain types of minor microscopic- to macroscopic-sized precipitation or exsolution phases, including some that are nanosized, that are observed in synthetic almandine (e.g., magnetite), as well as in more compositionally complex natural crystals (e.g., magnetite, rutile, ilmenite), may result from defect reactions. An explanation for their origin through minor amounts of defects in garnet has certain advantages over other models that have been put forth in the literature that assume strict garnet stoichiometry for their formation and/or open-system atomic transport over relatively long length scales. Physical properties, including magnetic, electrical conductivity and diffusion behavior, as well as the color, of almandine are also analyzed in terms of various possible model defects. It is difficult, if not impossible, to synthesize stoichiometric end-member almandine, Fe3Al2Si3O12, in the laboratory, as small amounts of extrinsic OH- and/or Fe3+ defects, for example

Exploring genetic suppression interactions on a global scale.

Science.gov (United States)

van Leeuwen, Jolanda; Pons, Carles; Mellor, Joseph C; Yamaguchi, Takafumi N; Friesen, Helena; Koschwanez, John; Ušaj, Mojca Mattiazzi; Pechlaner, Maria; Takar, Mehmet; Ušaj, Matej; VanderSluis, Benjamin; Andrusiak, Kerry; Bansal, Pritpal; Baryshnikova, Anastasia; Boone, Claire E; Cao, Jessica; Cote, Atina; Gebbia, Marinella; Horecka, Gene; Horecka, Ira; Kuzmin, Elena; Legro, Nicole; Liang, Wendy; van Lieshout, Natascha; McNee, Margaret; San Luis, Bryan-Joseph; Shaeri, Fatemeh; Shuteriqi, Ermira; Sun, Song; Yang, Lu; Youn, Ji-Young; Yuen, Michael; Costanzo, Michael; Gingras, Anne-Claude; Aloy, Patrick; Oostenbrink, Chris; Murray, Andrew; Graham, Todd R; Myers, Chad L; Andrews, Brenda J; Roth, Frederick P; Boone, Charles

2016-11-04

Genetic suppression occurs when the phenotypic defects caused by a mutation in a particular gene are rescued by a mutation in a second gene. To explore the principles of genetic suppression, we examined both literature-curated and unbiased experimental data, involving systematic genetic mapping and whole-genome sequencing, to generate a large-scale suppression network among yeast genes. Most suppression pairs identified novel relationships among functionally related genes, providing new insights into the functional wiring diagram of the cell. In addition to suppressor mutations, we identified frequent secondary mutations,in a subset of genes, that likely cause a delay in the onset of stationary phase, which appears to promote their enrichment within a propagating population. These findings allow us to formulate and quantify general mechanisms of genetic suppression. Copyright © 2016, American Association for the Advancement of Science.

Structural integrity evaluation of SG tube with surface wear-type defects

International Nuclear Information System (INIS)

Kim, Jong Min; Huh, Nam Su; Chang, Yoon Suk; Kim, Young Jin; Hwang, Seong Sik; Kim, Joung Soo

2006-01-01

During the last two decades, several guidelines have been developed and used for assessing the integrity of a defective Steam Generator (SG) tube that is generally caused by stress corrosion cracking or wall-thinning phenomenon. However, as some of SG tubes are also failed due to fretting and so on, alternative failure estimation schemes are required for relevant defects. In this paper, parametric three-dimensional Finite Element (FE) analyses are carried out under internal pressure condition to simulate the failure behavior of SG tubes with different defect configurations; elliptical wear, tapered and flat wear type defects. Maximum pressures based on material strengths are obtained from more than a hundred FE results to predict the failure of SG tube. After investigating the effect of key parameters such as defect depth, defect length and wrap angle, simplified failure estimation equations are proposed in relation to the equivalent stress at the deepest point in wear region. Comparison of failure pressures predicted by the proposed estimation scheme with corresponding burst test data showed a good agreement

Limb-body wall defect: experience of a reference service of fetal medicine from Southern Brazil.

Science.gov (United States)

Gazolla, Ana C; da Cunha, André C; Telles, Jorge A B; Betat, Rosilene da S; Romano, Mayara A; Marshall, Isabel; Gobatto, Amanda M; de H Bicca, Anna M; Arcolini, Camila P; Dal Pai, Thaís K V; Vieira, Luciane R; Targa, Luciano V; Betineli, Ildo; Zen, Paulo R G; Rosa, Rafael F M

2014-10-01

Limb-body wall defect is a rare condition characterized by a combination of large and complex defects of the ventral thorax and abdominal wall with craniofacial and limb anomalies. The aim of this study was to describe the experience of our fetal medicine service, a reference from Southern Brazil, with prenatally diagnosed patients with a limb-body wall defect in a 3 years period. Only patients who fulfilled the criteria suggested by Hunter et al. (2011) were included in the study. Clinical data and results of radiological and cytogenetic evaluation were collected from their medical records. Our sample was composed of 8 patients. Many of their mothers were younger than 25 years (50%) and in their first pregnancy (62.5%). It is noteworthy that one patient was referred due to suspected anencephaly and another due to a twin pregnancy with an embryonic sac. Craniofacial defects were verified in three patients (37.5%), thoracic/abdominal abnormalities in 6 (75%) and limb defects in eight (100%). Congenital heart defects were observed in five patients (62.5%). One of them presented a previously undescribed complex heart defect. The results disclosed that complementary exams, such as MRI and echocardiography, are important to better define the observed defects. Some of them, such as congenital heart defects, may be more common than previously reported. This definition is essential for the proper management of the pregnancy and genetic counseling of the family. The birth of these children must be planned with caution and for the prognosis a long survival possibility, despite unlikely and rare, must be considered. © 2014 Wiley Periodicals, Inc.

Bi-allelic Mutations in PKD1L1 Are Associated with Laterality Defects in Humans.

Science.gov (United States)

Vetrini, Francesco; D'Alessandro, Lisa C A; Akdemir, Zeynep C; Braxton, Alicia; Azamian, Mahshid S; Eldomery, Mohammad K; Miller, Kathryn; Kois, Chelsea; Sack, Virginia; Shur, Natasha; Rijhsinghani, Asha; Chandarana, Jignesh; Ding, Yan; Holtzman, Judy; Jhangiani, Shalini N; Muzny, Donna M; Gibbs, Richard A; Eng, Christine M; Hanchard, Neil A; Harel, Tamar; Rosenfeld, Jill A; Belmont, John W; Lupski, James R; Yang, Yaping

2016-10-06

Disruption of the establishment of left-right (L-R) asymmetry leads to situs anomalies ranging from situs inversus totalis (SIT) to situs ambiguus (heterotaxy). The genetic causes of laterality defects in humans are highly heterogeneous. Via whole-exome sequencing (WES), we identified homozygous mutations in PKD1L1 from three affected individuals in two unrelated families. PKD1L1 encodes a polycystin-1-like protein and its loss of function is known to cause laterality defects in mouse and medaka fish models. Family 1 had one fetus and one deceased child with heterotaxy and complex congenital heart malformations. WES identified a homozygous splicing mutation, c.6473+2_6473+3delTG, which disrupts the invariant splice donor site in intron 42, in both affected individuals. In the second family, a homozygous c.5072G>C (p.Cys1691Ser) missense mutation was detected in an individual with SIT and congenital heart disease. The p.Cys1691Ser substitution affects a highly conserved cysteine residue and is predicted by molecular modeling to disrupt a disulfide bridge essential for the proper folding of the G protein-coupled receptor proteolytic site (GPS) motif. Damaging effects associated with substitutions of this conserved cysteine residue in the GPS motif have also been reported in other genes, namely GPR56, BAI3, and PKD1 in human and lat-1 in C. elegans, further supporting the likely pathogenicity of p.Cys1691Ser in PKD1L1. The identification of bi-allelic PKD1L1 mutations recapitulates previous findings regarding phenotypic consequences of loss of function of the orthologous genes in mice and medaka fish and further expands our understanding of genetic contributions to laterality defects in humans. Copyright © 2016 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Defect-induced ferromagnetism in semiconductors: A controllable approach by particle irradiation

International Nuclear Information System (INIS)

Zhou, Shengqiang

2014-01-01

Making semiconductors ferromagnetic has been a long dream. One approach is to dope semiconductors with transition metals (TM). TM ions act as local moments and they couple with free carriers to develop collective magnetism. However, there are no fundamental reasons against the possibility of local moment formation from localized sp states. Recently, ferromagnetism was observed in nonmagnetically doped, but defective semiconductors or insulators including ZnO and TiO 2 . This kind of observation challenges the conventional understanding of ferromagnetism. Often the defect-induced ferromagnetism has been observed in samples prepared under non-optimized condition, i.e. by accident or by mistake. Therefore, in this field theory goes much ahead of experimental investigation. To understand the mechanism of the defect-induced ferromagnetism, one needs a better controlled method to create defects in the crystalline materials. As a nonequilibrium and reproducible approach of inducing defects, ion irradiation provides such a possibility. Energetic ions displace atoms from their equilibrium lattice sites, thus creating mainly vacancies, interstitials or antisites. The amount and the distribution of defects can be controlled by the ion fluence and energy. By ion irradiation, we have generated defect-induced ferromagnetism in ZnO, TiO 2 and SiC. In this short review, we also summarize some results by other groups using energetic ions to introduce defects, and thereby magnetism in various materials. Ion irradiation combined with proper characterizations of defects could allow us to clarify the local magnetic moments and the coupling mechanism in defective semiconductors. Otherwise we may have to build a new paradigm to understand the defect-induced ferromagnetism

The Genetic Architecture Underlying the Evolution of a Rare Piscivorous Life History Form in Brown Trout after Secondary Contact and Strong Introgression

Directory of Open Access Journals (Sweden)

Arne Jacobs

2018-05-01

Full Text Available Identifying the genetic basis underlying phenotypic divergence and reproductive isolation is a longstanding problem in evolutionary biology. Genetic signals of adaptation and reproductive isolation are often confounded by a wide range of factors, such as variation in demographic history or genomic features. Brown trout (Salmo trutta in the Loch Maree catchment, Scotland, exhibit reproductively isolated divergent life history morphs, including a rare piscivorous (ferox life history form displaying larger body size, greater longevity and delayed maturation compared to sympatric benthivorous brown trout. Using a dataset of 16,066 SNPs, we analyzed the evolutionary history and genetic architecture underlying this divergence. We found that ferox trout and benthivorous brown trout most likely evolved after recent secondary contact of two distinct glacial lineages, and identified 33 genomic outlier windows across the genome, of which several have most likely formed through selection. We further identified twelve candidate genes and biological pathways related to growth, development and immune response potentially underpinning the observed phenotypic differences. The identification of clear genomic signals divergent between life history phenotypes and potentially linked to reproductive isolation, through size assortative mating, as well as the identification of the underlying demographic history, highlights the power of genomic studies of young species pairs for understanding the factors shaping genetic differentiation.

Fibrous metaphyseal defects

International Nuclear Information System (INIS)

Ritschl, P.; Hajek, P.C.; Pechmann, U.

1989-01-01

Sixteen patients with fibrous metaphyseal defects were examined with both plain radiography and magnetic resonance (MR) imaging. Depending on the age of the fibrous metaphyseal defects, characteristic radiomorphologic changes were found which correlated well with MR images. Following intravenous Gadolinium-DTPA injection, fibrous metaphyseal defects invariably exhibited a hyperintense border and signal enhancement. (orig./GDG)

Defective ribosome assembly in Shwachman-Diamond syndrome.

Science.gov (United States)

Wong, Chi C; Traynor, David; Basse, Nicolas; Kay, Robert R; Warren, Alan J

2011-10-20

Shwachman-Diamond syndrome (SDS), a recessive leukemia predisposition disorder characterized by bone marrow failure, exocrine pancreatic insufficiency, skeletal abnormalities and poor growth, is caused by mutations in the highly conserved SBDS gene. Here, we test the hypothesis that defective ribosome biogenesis underlies the pathogenesis of SDS. We create conditional mutants in the essential SBDS ortholog of the ancient eukaryote Dictyostelium discoideum using temperature-sensitive, self-splicing inteins, showing that mutant cells fail to grow at the restrictive temperature because ribosomal subunit joining is markedly impaired. Remarkably, wild type human SBDS complements the growth and ribosome assembly defects in mutant Dictyostelium cells, but disease-associated human SBDS variants are defective. SBDS directly interacts with the GTPase elongation factor-like 1 (EFL1) on nascent 60S subunits in vivo and together they catalyze eviction of the ribosome antiassociation factor eukaryotic initiation factor 6 (eIF6), a prerequisite for the translational activation of ribosomes. Importantly, lymphoblasts from SDS patients harbor a striking defect in ribosomal subunit joining whose magnitude is inversely proportional to the level of SBDS protein. These findings in Dictyostelium and SDS patient cells provide compelling support for the hypothesis that SDS is a ribosomopathy caused by corruption of an essential cytoplasmic step in 60S subunit maturation.

Genetic modifiers of Duchenne and facioscapulohumeral muscular dystrophies.

Science.gov (United States)

Hightower, Rylie M; Alexander, Matthew S

2018-01-01

Muscular dystrophy is defined as the progressive wasting of skeletal muscles that is caused by inherited or spontaneous genetic mutations. Next-generation sequencing has greatly improved the accuracy and speed of diagnosis for different types of muscular dystrophy. Advancements in depth of coverage, convenience, and overall reduced cost have led to the identification of genetic modifiers that are responsible for phenotypic variability in affected patients. These genetic modifiers have been postulated to explain key differences in disease phenotypes, including age of loss of ambulation, steroid responsiveness, and the presence or absence of cardiac defects in patients with the same form of muscular dystrophy. This review highlights recent findings on genetic modifiers of Duchenne and facioscapulohumeral muscular dystrophies based on animal and clinical studies. These genetic modifiers hold great promise to be developed into novel therapeutic targets for the treatment of muscular dystrophies. Muscle Nerve 57: 6-15, 2018. © 2017 Wiley Periodicals, Inc.

Shallow nitrogen ion implantation: Evolution of chemical state and defect structure in titanium

Energy Technology Data Exchange (ETDEWEB)

Manojkumar, P.A., E-mail: manoj@igcar.gov.in [Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Chirayath, V.A.; Balamurugan, A.K.; Krishna, Nanda Gopala; Ilango, S.; Kamruddin, M.; Amarendra, G.; Tyagi, A.K. [Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Raj, Baldev [National Institute of Advanced Studies, Bangalore 560 012 (India)

2016-09-15

Highlights: • Low energy nitrogen ion implantation in titanium was studied. • Chemical and defect states were analyzed using SIMS, XPS and PAS. • SIMS and depth resolved XPS data showed good agreement. • Depth resolved defect and chemical states information were revealed. • Formation of 3 layers of defect states proposed to fit PAS results. - Abstract: Evolution of chemical states and defect structure in titanium during low energy nitrogen ion implantation by Plasma Immersion Ion Implantation (PIII) process is studied. The underlying process of chemical state evolution is investigated using secondary ion mass spectrometry and X-ray photoelectron spectroscopy. The implantation induced defect structure evolution as a function of dose is elucidated using variable energy positron annihilation Doppler broadening spectroscopy (PAS) and the results were corroborated with chemical state. Formation of 3 layers of defect state was modeled to fit PAS results.

Development of advanced methodology for defect assessment in FBR power plants

International Nuclear Information System (INIS)

Meshii, Toshiyuki; Asayama, Tai

2001-03-01

As a preparation for developing a code for FBR post construction code, (a) JSME Code NA1-2000 was reviewed on the standpoint of applying it to FBR power plants and the necessary methodologies for defect assessment for FBR plants were pointed out (b) large capacity-high speed fatigue crack propagation (FCP) testing system was developed and some data were acquired to evaluate the FCP characteristics under thermal stresses. Results showed that the extended research on the following items are necessary for developing FBR post construction code. (1) Development of assessment for multiple defects due to creep damage. Multiple defects due to creep damage are not considered in the existing code, which is established for nuclear power plants in service under negligible-creep temperature. Therefore method to assess the integrity of these multiple defects due to creep damage is necessary. (2) FCP resistance for small load. Since components of FBR power plants are designed to minimize thermal stresses, the accuracy of FCP resistance for small load is important to estimate the crack propagation under thermal stresses accurately. However, there is not a sufficient necessary FCP data for small loads, maybe because the data is time consuming. Therefore we developed a large capacity-high speed FCP testing system, made a guideline for accelerated test and acquired some data to meet the needs. Continuous efforts to accumulate small load FCP data for various materials are necessary. (author)

The reliability of ultrasonic inspection and the critical defect size

International Nuclear Information System (INIS)

Vasilchenko, G.S.; Bely, V.E.; Ovchinnikov, A.V.; Rivkin, E.Yu.

1991-01-01

The ability to detect fabrication and service-induced defects in the welded joints of components and pipelines in nuclear power stations by ultrasonic inspection when this is conducted by using standard instruments and procedures appears to be insufficient. This fact was confirmed by the research carried out in PISC program and other studies. In order to increase the accuracy of measurement and to obtain the additional information on the character of any defect in ultrasonic testing as well as the validity of applying nondestructive testing data to strength calculation, scientific researches have been promoted and carried out in the USSR in a program under the guidance of NPO CNIITMASH. The reliability of the ultrasonic control of welded joints and the ways and means for its improvement are discussed. The presentation of the parameters realized by the ultrasonic inspection of defects in the form of schema for the use in strength calculation is explained. The calculation of stress intensity factor, the estimation of critical defect size, and the estimation of acceptable defect size are reported. (K.I.)

ILT based defect simulation of inspection images accurately predicts mask defect printability on wafer

Science.gov (United States)

Deep, Prakash; Paninjath, Sankaranarayanan; Pereira, Mark; Buck, Peter

2016-05-01

At advanced technology nodes mask complexity has been increased because of large-scale use of resolution enhancement technologies (RET) which includes Optical Proximity Correction (OPC), Inverse Lithography Technology (ILT) and Source Mask Optimization (SMO). The number of defects detected during inspection of such mask increased drastically and differentiation of critical and non-critical defects are more challenging, complex and time consuming. Because of significant defectivity of EUVL masks and non-availability of actinic inspection, it is important and also challenging to predict the criticality of defects for printability on wafer. This is one of the significant barriers for the adoption of EUVL for semiconductor manufacturing. Techniques to decide criticality of defects from images captured using non actinic inspection images is desired till actinic inspection is not available. High resolution inspection of photomask images detects many defects which are used for process and mask qualification. Repairing all defects is not practical and probably not required, however it's imperative to know which defects are severe enough to impact wafer before repair. Additionally, wafer printability check is always desired after repairing a defect. AIMSTM review is the industry standard for this, however doing AIMSTM review for all defects is expensive and very time consuming. Fast, accurate and an economical mechanism is desired which can predict defect printability on wafer accurately and quickly from images captured using high resolution inspection machine. Predicting defect printability from such images is challenging due to the fact that the high resolution images do not correlate with actual mask contours. The challenge is increased due to use of different optical condition during inspection other than actual scanner condition, and defects found in such images do not have correlation with actual impact on wafer. Our automated defect simulation tool predicts

Use of porous silicon to minimize oxidation induced stacking fault defects in silicon

International Nuclear Information System (INIS)

Shieh, S.Y.; Evans, J.W.

1992-01-01

This paper presents methods for minimizing stacking fault defects, generated during oxidation of silicon, include damaging the back of the wafer or depositing poly-silicon on the back. In either case a highly defective structure is created and this is capable of gettering either self-interstitials or impurities which promote nucleation of stacking fault defects. A novel method of minimizing these defects is to form a patch of porous silicon on the back of the wafer by electrochemical etching. Annealing under inert gas prior to oxidation may then result in the necessary gettering. Experiments were carried out in which wafers were subjected to this treatment. Subsequent to oxidation, the wafers were etched to remove oxide and reveal defects. The regions of the wafer adjacent to the porous silicon patch were defect-free, whereas remote regions had defects. Deep level transient spectroscopy has been used to examine the gettering capability of porous silicon, and the paper discusses the mechanism by which the porous silicon getters

Genetic analysis of fertility restoration under CGMS system in rice ...

Indian Academy of Sciences (India)

restore complete fertility of a certain CMS line by various restorer lines (Tan et ... Keywords. rice; heterosis; three-way test cross; fertility restoration genetics. Journal of ..... plants indicating a strong genetic load of maintenance in. DE2. Table 8.

Defect detection based on extreme edge of defective region histogram

Directory of Open Access Journals (Sweden)

Zouhir Wakaf

2018-01-01

Full Text Available Automatic thresholding has been used by many applications in image processing and pattern recognition systems. Specific attention was given during inspection for quality control purposes in various industries like steel processing and textile manufacturing. Automatic thresholding problem has been addressed well by the commonly used Otsu method, which provides suitable results for thresholding images based on a histogram of bimodal distribution. However, the Otsu method fails when the histogram is unimodal or close to unimodal. Defects have different shapes and sizes, ranging from very small to large. The gray-level distributions of the image histogram can vary between unimodal and multimodal. Furthermore, Otsu-revised methods, like the valley-emphasis method and the background histogram mode extents, which overcome the drawbacks of the Otsu method, require preprocessing steps and fail to use the general threshold for multimodal defects. This study proposes a new automatic thresholding algorithm based on the acquisition of the defective region histogram and the selection of its extreme edge as the threshold value to segment all defective objects in the foreground from the image background. To evaluate the proposed defect-detection method, common standard images for experimentation were used. Experimental results of the proposed method show that the proposed method outperforms the current methods in terms of defect detection.

A comparison of neural tube defects identified by two independent routine recording systems for congenital malformations in Northern Ireland.

Science.gov (United States)

Nevin, N C; McDonald, J R; Walby, A L

1978-12-01

The efficiency of two systems for recording congenital malformations has been compared; one system, the Registrar General's Congenital Malformation Notification, is based on registering all malformed infants, and the other, the Child Health System, records all births. In Northern Ireland for three years [1974--1976], using multiple sources of ascertainment, a total of 686 infants with neural tube defects was identified among 79 783 live and stillbirths. The incidence for all neural tube defects in 8 60 per 1 000 births. The Registrar General's Congenital Malformation Notification System identified 83.6% whereas the Child Health System identified only 63.3% of all neural tube defects. Both systems together identified 86.2% of all neural tube defects. The two systems are suitable for monitoring of malformations and the addition of information from the Genetic Counselling Clinics would enhance the data for epidemiological studies.

Effect of radiation-induced substrate defects on microstrip gas chamber gain behaviour

International Nuclear Information System (INIS)

Pallares, A.; Brom, J.M.; Bergdolt, A.M.; Coffin, J.; Eberle, H.; Sigward, M.H.; Fontaine, J.C.; Barthe, S.; Schunck, J.P.

1998-01-01

The aim of this work was to quantify the influence of radiation-induced substrate defects on microstrip gas chamber (MSGC) gain behaviour. The first part of this paper focuses on radiation effects on a typical MSGC substrate: Desag D263 glass. Defect generation was studied for Desag D263 with pure silica (Suprasil 1) as a reference. We studied the evolution of defect concentration with respect to accumulated doses up to 480 kGy. Annealing studies of defects in Desag D263 were also performed. In the second part, the radiation sensitivity of Desag D263 glass has been linked to the behaviour of the detector under irradiation. Comparative gain measurements were taken before and after substrate irradiation at 10 and 80 kGy the minimal dose received during LHC operation and the dose for which defect density is maximum (respectively). (orig.)

P-N defect in GaNP studied by optically detected magnetic resonance

International Nuclear Information System (INIS)

Chen, W.M.; Thinh, N.Q.; Vorona, I.P.; Buyanova, I.A.; Xin, H.P.; Tu, C.W.

2003-01-01

We provide experimental evidence for an intrinsic defect in GaNP from optically detected magnetic resonance (ODMR). This defect is identified as a P-N complex, exhibiting hyperfine structure due to interactions with a nuclear spin I=((1)/(2)) of one P atom and also a nuclear spin I=1 due to one N atom. The introduction of the defect is assisted by the incorporation of N within the studied N composition range of up to 3.1%, under non-equilibrium growth conditions during gas-source molecular beam epitaxy. The corresponding ODMR spectrum was found to be isotropic, suggesting an A 1 symmetry of the defect state. The localization of the electron wave function at the P-N defect in GaNP is found to be even stronger than that for the isolated P Ga antisite in its parent binary compound GaP

Direct Observation of Radiation Defects: Experiment and Interpretation

International Nuclear Information System (INIS)

Dudarev, S.L.

2012-01-01

Electron microscopy is arguably the only available experimental method suitable for the direct visualization of nano-scale defect structures formed under irradiation. Images of dislocation loops and point-defect clusters in crystals are usually produced using diffraction contrast methods. For relatively large defects, a combination of dynamical imaging and image contrast simulations is required for determining the nature of visible radiation defects. At the same time, density functional theory (DFT) models developed over the last decade have provided unique information about the structure of nano-scale defects produced by irradiation, including the defects that are so small that they cannot be observed in an electron microscope, and about the pathways of migration and interaction between radiation defects. DFT models, involving no experimental input parameters and being as quantitatively accurate and informative as the most advanced experimental techniques for the direct observation of defects, have created a new paradigm for the scientific investigation of radiation damage phenomena. In particular, DFT models offer new insight into the origin of temperature-dependent response of materials to irradiation, a problem of pivotal significance for applications. By combining information derived from the first-principles models for radiation defects with information derived from small-scale experimental observations it may be possible to acquire quantitative knowledge about how materials respond to irradiation and, using this knowledge, develop materials suitable for advanced applications in fission and fusion. It now appears possible to pose the question about the development of integrated fusion power plant models, combining neutron transport calculations and microscopic models for microstructural evolution of materials, for example models for ab initio prediction of helium embrittlement. Such models, based on scientific principles and quantitative data, and developed

Genetic Parameter Estimates of Carcass Traits under National Scale Breeding Scheme for Beef Cattle

Directory of Open Access Journals (Sweden)

ChangHee Do

2016-08-01

productivity and carcass quality could be obtained under the national scale breeding scheme of Korea for Hanwoo and that continuous efforts to improve the breeding scheme should be made to increase genetic progress.

Rehabilitation of large maxillary defect with two-piece maxillary obturators

Directory of Open Access Journals (Sweden)

Kanchan P Dholam

2015-01-01

Full Text Available The insertion and removal of an obturator in large maxillary defects with or without trismus is difficult. Fabrication of a two-piece obturator in such cases overcomes this problem. This article describes rehabilitation of large maxillary defects with two piece maxillary obturator of three types. All these obturators have a maxillary plate and a bulb component, which are approximated together by various techniques namely, silicone cover, embedded magnets, and press studs. Prosthetic rehabilitation of large maxillary defects with two-piece obturators offers the possibility of adequate oral rehabilitation by fabricating light weight prosthesis, which is easy to use. The bulb covers the undercut areas of the defect enhancing the facial contour and retention. It facilitates easy examination of underlying tissues, recreation of the anatomic barrier between the oral and nasal cavities and restoration of the function and esthetics. Thus, it adds to the quality of life.

Band Structure Characteristics of Nacreous Composite Materials with Various Defects

Science.gov (United States)

Yin, J.; Zhang, S.; Zhang, H. W.; Chen, B. S.

2016-06-01

Nacreous composite materials have excellent mechanical properties, such as high strength, high toughness, and wide phononic band gap. In order to research band structure characteristics of nacreous composite materials with various defects, supercell models with the Brick-and-Mortar microstructure are considered. An efficient multi-level substructure algorithm is employed to discuss the band structure. Furthermore, two common systems with point and line defects and varied material parameters are discussed. In addition, band structures concerning straight and deflected crack defects are calculated by changing the shear modulus of the mortar. Finally, the sensitivity of band structures to the random material distribution is presented by considering different volume ratios of the brick. The results reveal that the first band gap of a nacreous composite material is insensitive to defects under certain conditions. It will be of great value to the design and synthesis of new nacreous composite materials for better dynamic properties.

Genetic variability of garlic accessions as revealed by agro-morphological traits evaluated under different environments.

Science.gov (United States)

Hoogerheide, E S S; Azevedo Filho, J A; Vencovsky, R; Zucchi, M I; Zago, B W; Pinheiro, J B

2017-05-31

The cultivated garlic (Allium sativum L.) displays a wide phenotypic diversity, which is derived from natural mutations and phenotypic plasticity, due to dependence on soil type, moisture, latitude, altitude and cultural practices, leading to a large number of cultivars. This study aimed to evaluate the genetic variability shown by 63 garlic accessions belonging to Instituto Agronômico de Campinas and the Escola Superior de Agricultura "Luiz de Queiroz" germplasm collections. We evaluated ten quantitative characters in experimental trials conducted under two localities of the State of São Paulo: Monte Alegre do Sul and Piracicaba, during the agricultural year of 2007, in a randomized blocks design with five replications. The Mahalanobis distance was used to measure genetic dissimilarities. The UPGMA method and Tocher's method were used as clustering procedures. Results indicated significant variation among accessions (P < 0.01) for all evaluated characters, except for the percentage of secondary bulb growth in MAS, indicating the existence of genetic variation for bulb production, and germplasm evaluation considering different environments is more reliable for the characterization of the genotypic variability among garlic accessions, since it diminishes the environmental effects in the clustering of genotypes.

Axenfeld-Rieger syndrome.

Science.gov (United States)

Seifi, M; Walter, M A

2018-06-01

Axenfeld-Rieger syndrome (ARS) is a clinically and genetically heterogeneous group of developmental disorders affecting primarily the anterior segment of the eye, often leading to secondary glaucoma. Patients with ARS may also present with systemic changes, including dental defects, mild craniofacial dysmorphism, and umbilical anomalies. ARS is inherited in an autosomal-dominant fashion; the underlying defect in 40% of patients is mutations in PITX2 or FOXC1. Here, an overview of the clinical spectrum of ARS is provided. As well, the known underlying genetic defects, clinical diagnostic possibilities, genetic counseling and treatments of ARS are discussed in detail. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Hydrogen interaction with radiation defects in p-type silicon

CERN Document Server

Feklisova, O V; Yakimov, E B; Weber, J

2001-01-01

Hydrogen interaction with radiation defects in p-type silicon has been investigated by deep-level non-stationary spectroscopy. Hydrogen is introduced into the high-energy electron-irradiated crystals under chemical etching in acid solutions at room temperature followed by the reverse-bias annealing at 380 K. It is observed that passivation of the irradiation-induced defects is accompanied by formation of novel electrically active defects with hydrogen-related profiles. Effect of hydrogen on the electrical activity of the C sub s C sub i complexes is shown for the first time. Based on the spatial distribution and passivation kinetics, possible nature of the novel complexes is analyzed. The radii for hydrogen capture by vacancies, K-centers, C sub s C sub i centers and the novel complexes are determined

Genetics of recessive cognitive disorders

OpenAIRE

Musante, Luciana; Ropers, H. Hilger

2014-01-01

Most severe forms of intellectual disability (ID) have specific genetic causes. Numerous X chromosome gene defects and disease-causing copy-number variants have been linked to ID and related disorders, and recent studies have revealed that sporadic cases are often due to dominant de novo mutations with low recurrence risk. For autosomal recessive ID (ARID) the recurrence risk is high and, in populations with frequent parental consanguinity, ARID is the most common form of ID. Even so, its elu...

Cost-benefit as weighed on genetic scales

International Nuclear Information System (INIS)

Grahn, D.

1976-01-01

The genetic cost that may be incurred by exposure to mutagenic agents in the coal and nuclear fuel cycles is assessed, using as a point of departure the presently estimated burden of spontaneously occurring genetic defects in human populations. Risk estimates are necessarily derived from radiation studies, but chemical mutagenic hazards can probably be evaluated relative to the known dose-response relationships of radiation exposure. Cost-benefit analyses for the coal and nuclear fuel cycles are discussed and translated into monetary terms. Coal-associated risks are almost entirely somatic while nuclear risks are somatic and genetic in equal proportions. Dollar costs per man-rem are concluded to be in the $100 range. Pollution abatement costs for the nuclear cycle lie in the range of several hundreds to many thousands of dollars per man-rem reduction. It is considered appropriate to incur such costs, because genetic risks to future generations involve primarily societal and ethical issues rather than economic considerations

Neural tube defects – recent advances, unsolved questions and controversies

Science.gov (United States)

Copp, Andrew J.; Stanier, Philip; Greene, Nicholas D. E.

2014-01-01

Neural tube defects (NTDs) are severe congenital malformations affecting around 1 in every 1000 pregnancies. Here we review recent advances and currently unsolved issues in the NTD field. An innovation in clinical management has come from the demonstration that closure of open spina bifida lesions in utero can diminish neurological dysfunction in children. Primary prevention by folic acid has been enhanced through introduction of mandatory food fortification in some countries, although not yet in UK. Genetic predisposition comprises the majority of NTD risk, and genes that regulate folate one-carbon metabolism and planar cell polarity have been strongly implicated. The sequence of human neural tube closure events remains controversial, but study of mouse NTD models shows that anencephaly, open spina bifida and craniorachischisis result from failure of primary neurulation, while skin-covered spinal dysraphism results from defective secondary neurulation. Other ‘NTD’ malformations, such as encephalocele, are likely to be post-neurulation disorders. PMID:23790957

Synthetic Defects for Vibrothermography

Science.gov (United States)

Renshaw, Jeremy; Holland, Stephen D.; Thompson, R. Bruce; Eisenmann, David J.

2010-02-01

Synthetic defects are an important tool used for characterizing the performance of nondestructive evaluation techniques. Viscous material-filled synthetic defects were developed for use in vibrothermography (also known as sonic IR) as a tool to improve inspection accuracy and reliability. This paper describes how the heat-generation response of these VMF synthetic defects is similar to the response of real defects. It also shows how VMF defects can be applied to improve inspection accuracy for complex industrial parts and presents a study of their application in an aircraft engine stator vane.