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Sample records for unique supernumerary ring

  1. Unique case of a geminated supernumerary tooth with trifid crown

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    Ather, Amber; Ather, Hunaiza; Sheth, Sanket Milan; Muliya, Vidya Saraswathi [Manipal College of Dental Sciences, Manipal (Korea, Republic of)

    2012-09-15

    Gemination, a relatively uncommon dental anomaly, is characterized by its peculiar representation as a tooth with a bifid crown and a common root and root canal. It usually occurs in primary dentition. To come across gemination in a supernumerary tooth is a rare phenomenon. The purpose of this paper is to present a unique case of hyperdontia wherein gemination in an impacted supernumerary tooth resulted in a trifid crown unlike the usual bifid crown. The role of conventional radiographs as well as computed tomography, to accurately determine the morphology and spatial location, and to arrive at a diagnosis, is also emphasized in this paper.

  2. Chromosomal breakpoints characterization of two supernumerary ring chromosomes 20.

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    Guediche, N; Brisset, S; Benichou, J-J; Guérin, N; Mabboux, P; Maurin, M-L; Bas, C; Laroudie, M; Picone, O; Goldszmidt, D; Prévot, S; Labrune, P; Tachdjian, G

    2010-02-01

    The occurrence of an additional ring chromosome 20 is a rare chromosome abnormality, and no common phenotype has been yet described. We report on two new patients presenting with a supernumerary ring chromosome 20 both prenatally diagnosed. The first presented with intrauterine growth retardation and some craniofacial dysmorphism, and the second case had a normal phenotype except for obesity. Conventional cytogenetic studies showed for each patient a small supernumerary marker chromosome (SMC). Using fluorescence in situ hybridization, these SMCs corresponded to ring chromosomes 20 including a part of short and long arms of chromosome 20. Detailed molecular cytogenetic characterization showed different breakpoints (20p11.23 and 20q11.23 for Patient 1 and 20p11.21 and 20q11.21 for Patient 2) and sizes of the two ring chromosomes 20 (13.6 Mb for case 1 and 4.8 Mb for case 2). Review of the 13 case reports of an extra r(20) ascertained postnatally (8 cases) and prenatally (5 cases) showed varying degrees of phenotypic abnormalities. We document a detailed molecular cytogenetic chromosomal breakpoints characterization of two cases of supernumerary ring chromosomes 20. These results emphasize the need to characterize precisely chromosomal breakpoints of supernumerary ring chromosomes 20 in order to establish genotype-phenotype correlation. This report may be helpful for prediction of natural history and outcome, particularly in prenatal diagnosis.

  3. Supernumerary ring chromosome 17 identified by fluorescent in situ hybridization

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    Fagan, K. [Hunter Area Pathology Service, New South Wales (Australia); Edwards, M. [Western Suburbs Hospital, New South Wales (Australia)

    1997-04-14

    We present a patient with multiple anomalies and severe developmental delay. A small supernumerary ring chromosome was found in 40% of her lymphocyte cells at birth. The origin of the marker chromosome could not be determined by GTG banding, but fluorescent in situ hybridization (FISH) later identified the marker as deriving from chromosome 17. 20 refs., 2 figs., 1 tab.

  4. Supernumerary ring chromosome: an etiology for Pallister-Killian syndrome?

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    Lloveras, E; Canellas, A; Cirigliano, V; Català, V; Cerdan, C; Plaja, A

    2013-01-01

    Characterization of marker chromosomes before the introduction of array CGH (aCGH) assays was only based on their banding patterns (G, C, and NOR staining) and fluorescent in situ hybridization techniques. The use of aCGH greatly improves the identification of marker chromosomes in some cases. We describe an atypical case of Pallister-Killian syndrome (PKS) detected at prenatal diagnosis with a very unusual cytogenetic presentation: a supernumerary ring chromosome including two copies of 12p. A similar anomaly described in a postnatal patient suggests ring chromosome as a possible cause of PKS. Extra ring chromosomes might be a more common etiology for PKS than previously thought, given the difficulty in their characterization before the advent of aCGH.

  5. Low grade mosaic for a complex supernumerary ring chromosome 18 in an adult patient with multiple congenital anomalies

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    Hoogeboom A Jeannette M

    2010-07-01

    Full Text Available Abstract Background Several cases have been reported of patients with a ring chromosome 18 replacing one of the normal chromosomes 18. Less common are patients with a supernumerary ring chromosomes 18. High resolution whole genome examination in patients with multiple congenital abnormalities might reveal cytogenetic abnormalities of an unexpected complexity. Results We report a 24 years old male patient with lower spinal anomalies, hypospadia, bifid scrotum, cryptorchism, anal atresia, kidney stones, urethra anomalies, radial dysplasia, and a hypoplastic thumb. Some of the anomalies overlap with the VACTERL association. Chromosome analysis of cultured peripheral blood lymphocytes revealed an additional ring chromosome in 13% of the metaphases. Both parents had a normal karyotype, demonstrating the de novo origin of this ring chromosome. FISH analysis using whole chromosome paints showed that the additional chromosomal material was derived from chromosome 18. Chromosome analysis of cultured fibroblasts revealed only one cell with the supernumerary ring chromosome in the 400 analyzed. To characterize the ring chromosome in more detail peripheral blood derived DNA was analyzed using SNP-arrays. The array results indicated a 5 Mb gain of the pericentromeric region of chromosome 18q10-q11.2. FISH analysis using BAC-probes located in the region indicated the presence of 6 signals on the r(18 chromosome. In addition, microsatellite analysis demonstrated that the unique supernumerary ring chromosome was paternally derived and both normal copies showed biparental disomy. Conclusions We report on an adult patient with multiple congenital abnormalities who had in 13% of his cells a unique supernumerary ring chromosome 18 that was composed of 6 copies of the 5 Mb gene rich region of 18q11.

  6. Pallister-Killian syndrome caused by mosaicism for a supernumerary ring chromosome 12p.

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    Yeung, Alison; Francis, David; Giouzeppos, Olivia; Amor, David J

    2009-03-01

    Pallister-Killian syndrome (PKS) is a rare but distinctive chromosomal syndrome distinguished by severe intellectual impairment, characteristic facial features, and variable structural anomalies. The characteristic cytogenetic abnormality in PKS is a supernumerary isochromosome 12p that confers mosaic tetrasomy. We describe a female child with PKS in whom tetrasomy 12p resulted from a supernumerary ring chromosome containing two copies of chromosome 12cen --> p13, a novel cytogenetic finding. The ring chromosome exhibited tissue-limited mosaicism, being absent in blood but detected in 38% of buccal mucosa cells and 41% of skin fibroblasts. Our patient demonstrated the typical dysmorphic characteristics of PKS, but her development was relatively advanced in comparison to children with isochromosome PKS. Her milder developmental phenotype may be attributable to differences in the mosaic distribution or the genomic content of the ring chromosome compared to mosaic isochromosome 12p.

  7. Supernumerary ring chromosome 20 characterized by fluorescence in situ hybridization

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    Van Langen, Irene M.; Otter, Mariëlle A.; Aronson, Daniël C.; Overweg-Plandsoen, W.C.G.; Hennekam, Raoul C.M.; Leschot, Nico J.; Hoovers, Jan M.N.

    1996-01-01

    We report on a boy with mild dysmorphic features and developmental delay, in whom karyotyping showed an additional minute ring chromosome in 60% of metaphases. Fluorescence in situ hybridization (FISH) with a centromere specific probe demonstrated that the ring chromosome contained the centromeric r

  8. Molecular cytogenetic characterization of a small, familial supernumerary ring chromosome 7 associated with mental retardation and an abnormal phenotype

    NARCIS (Netherlands)

    Tan-Sindhunata, G; Castedo, S; Leegte, B; Mulder, [No Value; van der Veen, AYV; van der Hout, AHV; van Essen, AJ

    2000-01-01

    A family is described in which a mother and two of her children were mosaic for a small supernumerary ring chromosome. As the origin of the ring chromosome could not be determined by routine cytogenetic studies, fluorescent in situ hybridization was performed, which indicated that the ring chromosom

  9. Low grade mosaic for a complex supernumerary ring chromosome 18 in an adult patient with multiple congenital anomalies

    NARCIS (Netherlands)

    L.T. van der Veken (Lars); M.M.J. Dieleman (Marianne); H. Douben (Hannie); J.C. van de Brug (Judith); R. van de Graaf (Raoul); A.J.M. Hoogeboom; P.J. Poddighe (Pino); J.E.M.M. de Klein (Annelies)

    2010-01-01

    textabstractBackground. Several cases have been reported of patients with a ring chromosome 18 replacing one of the normal chromosomes 18. Less common are patients with a supernumerary ring chromosomes 18. High resolution whole genome examination in patients with multiple congenital abnormalities mi

  10. Human ring chromosomes and small supernumerary marker chromosomes-do they have telomeres?

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    Guilherme, Roberta Santos; Klein, Elisabeth; Venner, Claudia; Hamid, Ahmed B; Bhatt, Samarth; Melaragno, Maria Isabel; Volleth, Marianne; Polityko, Anna; Kulpanovich, Anna; Kosyakova, Nadezda; Liehr, Thomas

    2012-10-01

    Ring chromosomes and small supernumerary marker chromosomes (sSMC) are enigmatic types of derivative chromosomes, in which the telomeres are thought to play a crucial role in their formation and stabilization. Considering that there are only a few studies that evaluate the presence of telomeric sequences in ring chromosomes and on sSMC, here, we analyzed 14 ring chromosomes and 29 sSMC for the presence of telomeric sequences through fluorescence in situ hybridization (FISH). The results showed that ring chromosomes can actually fall into two groups: the ones with or without telomeres. Additionally, telomeric signals were detectable at both ends of centric and neocentric sSMC with inverted duplication shape, as well as in complex sSMC. Apart from that, generally both ring- and centric minute-shaped sSMC did not present telomeric sequences neither detectable by FISH nor by a second protein-directed immunohistochemical approach. However, the fact that telomeres are absent does not automatically mean that the sSMC has a ring shape, as often deduced in the previous literature. Overall, the results obtained by FISH studies directed against telomeres need to be checked carefully by other approaches.

  11. Molecular cytogenetic characterization of a small, familial supernumerary ring chromosome 7 associated with mental retardation and an abnormal phenotype.

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    Tan-Sindhunata, G; Castedo, S; Leegte, B; Mulder, I; vd Veen, A Y; vd Hout, A H; Wiersma, T J; van Essen, A J

    2000-05-15

    A family is described in which a mother and two of her children were mosaic for a small supernumerary ring chromosome. As the origin of the ring chromosome could not be determined by routine cytogenetic studies, fluorescent in situ hybridization was performed, which indicated that the ring chromosome was derived from the pericentromeric region of chromosome 7. Further characterization with a YAC-probe showed the involvement of the proximal q-arm of chromosome 7. Both sibs had speech difficulties and were mildly mentally retarded whereas the mother's intelligence was at the lower end of the normal range. They all had an unusual face, characterized by a flat profile, short forehead, downslant of the palpebral fissures, high and broad nasal bridge, simply formed ears, and prognathia. This is the second report of a small supernumerary ring chromosome derived from the pericentromeric region of chromosome 7, and the described clinical phenotype differs from that delineated in the previous report.

  12. A note on uniquely (nil clean ring

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    Shervin Sahebi

    2014-05-01

    Full Text Available A ring $R$ is uniquely (nil clean in case for any $a\\in R$‎ ‎there exists a uniquely idempotent $e\\in R$ such that $a-e$ is‎ ‎invertible (nilpotent‎. ‎Let‎ ‎$C=\\small\\left(‎‎\\begin{array}{cc}‎‎A & V \\\\‎ ‎W & B‎‎\\end{array}‎‎\\right$‎ ‎be the Morita Context ring‎. ‎We determine conditions under which the rings $A‎, ‎B$‎ ‎are uniquely (nil clean‎. ‎Moreover we show that the center of a uniquely (nil‎‎clean ring is uniquely (nil clean.

  13. Double dens invaginatus in an impacted molariform supernumerary tooth: An unique case

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    Anegundi R

    2008-05-01

    Full Text Available Dens invaginatus is a relatively rare developmental anomaly affecting usually the permanent maxillary lateral incisor. Various factors have been put forward regarding its pathogenesis. Involvement of crown/root has been reported as the coronal and radicular variety of dens invaginatus. One of the rarest variant is the Double dens invaginatus and only a few cases have been reported in the literature.This article focuses on a case of double dens invaginatus in an impacted maxillary anterior supernumerary tooth, the associated complications and its management

  14. Characterization of a prenatally assessed de novo supernumerary minute ring chromosome 20 in a phenotypically normal male

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    Garas Antonios

    2009-01-01

    Full Text Available Abstract Background The heterogeneous group of small supernumerary marker chromosomes (sSMCs presents serious counseling problems, especially if they are present de novo and diagnosed prenatally. The incidence has been estimated at 1 in 1000 prenatal samples. We present a case of mosaic sSMC diagnosed prenatally after amniocentesis. The sSMC was characterized by various molecular cytogenetic techniques and determined to be a r(20 chromosome. After genetic counseling, the parents decided to continue the pregnancy, and a boy with minor phenotypic variants was born after 39 weeks of pregnancy. The case is compared with four other cases of prenatally detected r(20 mosaicism. Results Here we describe a 3 months old male child with normal pre- and postnatal development and with a de novo ring supernumerary marker chromosome in amniocytes cultures. Using new fluorescence in situ hybridization (FISH techniques, three distinguishable sSMCs (cryptic mosaicism, all derived from chromosome 20, were observed, including ring and minute chromosomes. This heterogeneity was impossible to detect by the conventional G-banding technique or conventional FISH technique that were used before the application of new FISH techniques (subcentromere-specific multicolor-FISH [subcenM-FISH] and a probe, specific for the 20p12.2 band. The sSMC present in 25% of the cells was present as r(20(::p12.2~12.3->q11.1::5/r(20;20(::p12.1->q11.1::q11.1 >p12.1::2/min(20;20(:p12.1->q11.1::q11.1->p12.1:1. The final karyotype was 47,XY,+r(20[25%]/46,XY[75%]. Conclusion We emphasize the importance of application of molecular cytogenetics in a prenatally diagnostic laboratory and description of more cases to enable a better genetic counseling and risk evaluation.

  15. Fusion of the FUS and CREB3L2 genes in a supernumerary ring chromosome in low-grade fibromyxoid sarcoma.

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    Bartuma, Hammurabi; Möller, Emely; Collin, Anna; Domanski, Henryk A; Von Steyern, Fredrik Vult; Mandahl, Nils; Mertens, Fredrik

    2010-06-01

    Low-grade fibromyxoid sarcoma (LGFMS) is a rare, low-grade malignant soft tissue tumor that is often mistaken for either benign or more malignant tumor types. Commonly, this tumor affects young adults and typically arises in the deep proximal extremities or trunk with frequent recurrences and can metastasize to the lungs many years later. Most cases have a recurrent balanced translocation involving chromosomes 7 and 16, t(7;16)(q32-34;p11), which leads to the fusion of the FUS and CREB3L2 genes. However, supernumerary ring chromosomes have been identified in a subset of FUS/CREB3L2-positive LGFMS, but it has not yet been formally demonstrated that such ring chromosomes harbor the FUS/CREB3L2 fusion gene. Here, we report the genetic findings of a supernumerary ring chromosome from an LGFMS from a 77-year-old man. Chromosome banding analysis revealed a supernumerary ring chromosome, and further studies with fluorescence in situ hybridization and reverse transcriptase-polymerase chain reaction (RT-PCR) showed that the ring contained material from chromosomes 7 and 16, that the FUS gene was present in two rearranged copies, and that it expressed the FUS/CREB3L2 fusion gene. Moreover, an assessment of previously reported cases showed that tumors with ring chromosomes relapsed more often than tumors with a balanced t(7;16), suggesting that ring formation in LGFMS is correlated with tumor progression. Copyright 2010 Elsevier Inc. All rights reserved.

  16. Supernumerary ring chromosomes derived from the long arm of chromosome 12 as the primary cytogenetic anomaly in a rare soft tissue chondroma.

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    Shadan, F F; Mascarello, J T; Newbury, R O; Dennis, T; Spallone, P; Stock, A D

    2000-04-15

    Supernumerary ring chromosomes varying with respect to both size and number were found as the primary cytogenetic anomaly in a rare benign soft tissue chondroma resected from the floor of the mouth of a 3-year-old girl. Reverse fluorescence in situ hybridization paint probes prepared by polymerase chain reaction from microdissected rings produced fluorescent signal over two large but discontinuous parts of the chromosome 12 long arm, subdivided into four regions. This case expands the spectrum of mesenchymal neoplasms in which ring chromosomes have been described as the primary genetic anomaly. A review of the literature reporting similar findings in other soft tissue tumors further supports the possibility that low-level amplification of chromosome 12 long-arm regions may contribute to abnormal cellular proliferation in a variety of mesenchymal tumors. Genes implicated in the control of the cell cycle such as sarcoma amplified sequence (SAS), the human homolog of the murine double-minute type 2 gene (MDM-2), proto-oncogenes CHOP/GADD153, GLI, A2MR, cyclin-dependent kinase (CDK4), and the high mobility group (HMGIC) gene implicated in mesenchymal tumorigenesis are all located on the long arm of chromosome 12. Chromosomal abnormalities involving the 12q13-q15 region are associated with a wide range of benign soft tissue tumors and sarcomas.

  17. Prenatal Diagnosis of a Fetus with de novo Supernumerary Ring Chromosome 16 Characterized by Array Comparative Genomic Hybridization

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    Pietro Cignini

    2011-09-01

    Full Text Available A fetus with de novo ring chromosome 16 is presented. At 20 weeks' gestation, ultrasound examination demonstrated bilateral clubfoot, bilateral renal pyelectasis, hypoplasia of the corpus callosum, and transposition of the great vessel. Amniocentesis was performed. Chromosome analysis identified a ring chromosome 16 [47,XY,r(16] and array comparative genomic hybridization (a-CGH demonstrated that the ring included the euchromatic portion 16p11.2. Postmortem examination confirmed prenatal findings. This is the first case of de novo ring chromosome 16 diagnosed prenatally with a new phenotypic pattern and also reinforces the importance of offering amniocentesis with a-CGH if fetal anomalies are detected.

  18. Full Descripion of ring varieties whose finite rings are uniquely determined by their zero-divisor graphs

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    Maltsev, Yu N; Kuzmina, A S

    2012-01-01

    The zero-divisor graph $\\Gamma(R)$ of an associative ring $R$ is the graph whose vertices are all nonzero zero-divisors (one-sided and two-sided) of $R$, and two distinct vertices $x$ and $y$ are joined by an edge iff either $xy=0$ or $yx=0$. In the present paper, we give a full description of ring varieties where every finite ring is uniquely determined by its zero-divisor graph.

  19. Is the schatzki ring a unique esophageal entity?

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    Michaela Müller; Ines Gockel; Philip Hedwig; Alexander J Eckardt; Kathrin Kuhr; Jochem K(o)nig; Volker F Eckardt

    2011-01-01

    AIM: To study, whether the association of Schatzki rings with other esophageal disorders support one of the theories about its etiology.METHODS: From 1987 until 2007, all patients with newly diagnosed symptomatic Schatzki rings (SRs)were prospectively registered and followed. All of them underwent structured interviews with regards to clinical symptoms, as well as endoscopic and/or radiographic examinations.Endoscopic and radiographic studies determined the presence of an SR and additional morphological abnormalities.RESULTS: One hundred and sixty-seven patients (125 male, 42 female) with a mean age of 57.1 ± 14.6 years were studied. All patients complained of intermittent dysphagia for solid food and 113 (79.6%) patients had a history of food impaction. Patients experienced symptoms for a mean of 4.7 ± 5.2 years before diagnosis. Only in 23.4% of the 64 patients who had endoscopic and/or radiological examinations before their first presentation to our clinic, was the SR previously diagnosed. At presentation, the mean ring diameter was 13.9 ± 4.97 mm. One hundred and sixty-two (97%) patients showed a sliding hiatal hernia. Erosive reflux esophagitis was found in 47 (28.1%) patients. Twenty-six (15.6%) of 167 patients showed single or multiple esophageal webs; five (3.0%) patients exhibited eosinophilic esophagitis; and four (2.4%) had esophageal diverticula. Four (7%) of 57 patients undergoing esophageal manometry had nonspecific esophageal motility disorders.CONCLUSION: Schatzki rings are frequently associated with additional esophageal disorders, which support the assumption of a multifactorial etiology. Despite typical symptoms, SRs might be overlooked.

  20. Management of supernumerary teeth

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    Abhishek Parolia

    2011-01-01

    Full Text Available Supernumerary paramolars are the rare anomalies of the maxillofacial complex. These are more common in the maxilla than in the mandible. This article reviews the etiology, frequency, classification, complications, diagnosis and management of supernumerary teeth (bilateral maxillary paramolars

  1. Intracranial supernumerary tooth

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    Sjoeberg, S.; Loerinc, P.

    1984-12-01

    Case report of an accidentally diagnosed supernumerary tooth in the superior orbital fissure. Computed tomography (CT) contributed with a more precise localization of the tooth being situated between the orbit and the brain. CT also showed that there was no cyst or other pathological process around the supernumerary tooth, which is plausible and frequently reported in the literature.

  2. A New GCD Algorithm for Quadratic Number Rings with Unique Factorization

    DEFF Research Database (Denmark)

    Agarwal, Saurabh; Frandsen, Gudmund Skovbjerg

    2006-01-01

    We present an algorithm to compute a greatest common divisor of two integers in a quadratic number ring that is a unique factorization domain. The algorithm uses bit operations in a ring of discriminant Δ. This appears to be the first gcd algorithm of complexity o(n 2) for any fixed non...

  3. Supernumerary teeth in clinical practice

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    Anna K. Szkaradkiewicz

    2011-07-01

    Full Text Available Introduction: Hyperdontia is the condition of having supernumerary teeth, or teeth which appear in addition to the regular number of teeth. The prevalence rates of supernumerary teeth in the permanent dentition amounts 0.1-6.9%, and in deciduous dentition 0.4-0.8%. The presence of supernumerary teeth can be found in everyday dental practice.Case presentation: We describe 3 cases of patients with supernumerary teeth. First patient had supernumerary lateral incisor 12s, second - premolar fused, multicuspid, supernumerary deciduous tooth 64s of having several interconnected roots, and third - erupted odontoma between teeth 13 and 14. In all cases treatment involved the removal of the supernumerary tooth.Conclusions: The decision on proceeding with the supernumerary teeth should be based on the full clinical picture and interview. Early diagnosis and removal of supernumerary teeth allow to avoid or reduce possible complications.

  4. Unique genomic structure and distinct mitotic behavior of ring chromosome 21 in two unrelated cases.

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    Zhang, H Z; Xu, F; Seashore, M; Li, P

    2012-01-01

    A ring chromosome replacing a normal chromosome could involve variable structural rearrangements and mitotic instability. However, most previously reported cases lacked further genomic characterization. High-resolution oligonucleotide array comparative genomic hybridization with single-nucleotide polymorphism typing (aCGH+SNP) was used to study 2 unrelated cases with a ring chromosome 21. Case 1 had severe myopia, hypotonia, joint hypermobility, speech delay, and dysmorphic features. aCGH detected a 1.275-Mb duplication of 21q22.12-q22.13 and a 6.731-Mb distal deletion at 21q22.2. Case 2 showed severe growth and developmental retardations, intractable seizures, and dysmorphic features. aCGH revealed a contiguous pattern of a 3.612- Mb deletion of 21q22.12-q22.2, a 4.568-Mb duplication of 21q22.2-q22.3, and a 2.243-Mb distal deletion at 21q22.3. Mitotic instability was noted in 13, 30, and 76% of in vitro cultured metaphase cells, interphase cells, and leukocyte DNA, respectively. The different phenotypes of these 2 cases are likely associated with the unique genomic structure and distinct mitotic behavior of their ring chromosome 21. These 2 cases represent a subtype of ring chromosome 21 probably involving somatic dicentric ring breakage and reunion. A cytogenomic approach is proposed for characterizing the genomic structure and mitotic instability of ring chromosome abnormalities.

  5. Black rings, supertubes, and a stringy resolution of black hole non-uniqueness

    Energy Technology Data Exchange (ETDEWEB)

    Elvang, Henriette [Department of Physics, UCSB, Santa Barbara, CA (United States)]. E-mail: elvang@physics.ucsb.edu; Emparan, Roberto [Institucio Catalana de Recerca i Estudis Avancats (ICREA), Departament de Fisica Fonamental (Spain); C.E.R. en Astrofisica, Fisica de Particules i Cosmologia, Universitat de Barcelona, Barcelona (Spain)]. E-mail: emparan@ub.edu

    2003-11-01

    In order to address the issues raised by the recent discovery of non-uniqueness of black holes in five dimensions, we construct a solution of string theory at low energies describing a five-dimensional spinning black ring with three charges that can be interpreted as D1-brane, D5-brane, and momentum charges. The solution possesses closed timelike curves (CTCs) and other pathologies, whose origin we clarify. These pathologies can be avoided by setting any one of the charges, e.g., the momentum, to zero. We argue that the D1-D5-charged black ring, lifted to six dimensions, describes the thermal excitation of a supersymmetric D1-D5 supertube, which is in the same U-duality class as the D0-F1 supertube. We explain how the stringy microscopic description of the D1-D5 system distinguishes between a spherical black hole and a black ring with the same asymptotic charges, and therefore provides a (partial) resolution of the non-uniqueness of black holes in five dimensions. (author)

  6. Supernumerary Teeth in Nepalese Children

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    Varun Pratap Singh

    2014-01-01

    Full Text Available Objective. The objectives of the present study were to investigate the prevalence and characteristics of supernumerary teeth in a patient sample of Nepalese children. Study Design. A survey was performed on 2684 patients (1829 females and 1035 males ranging in age from 6 to 14 for the presence of supernumerary teeth. For each patient with supernumerary teeth the demographic variables (age and sex, number, location, eruption status, and morphology were recorded. Descriptive statistics were performed. Results. Supernumerary teeth were detected in 46 subjects (1.6%, of which 26 were males and 20 were females with a male : female ratio of 1.3 : 1. The most commonly found supernumerary tooth was mesiodens followed by maxillary premolars, maxillary lateral incisor, and mandibular lateral incisor. Of the 55 supernumerary teeth examined, 58.18% (n=32 had conical morphology, followed by tuberculate (30.90%, n=17 and supplemental (10.90%, n=6 forms. The majority of the supernumerary teeth were erupted (56.36%, n=31. Conclusion. The prevalence of supernumerary teeth in Nepalese children was found to be 1.6%, the most frequent type being mesiodens. Conical morphology was found to be the most common form of supernumerary tooth.

  7. Supernumerary teeth in Nepalese children.

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    Singh, Varun Pratap; Sharma, Amita; Sharma, Sonam

    2014-01-01

    The objectives of the present study were to investigate the prevalence and characteristics of supernumerary teeth in a patient sample of Nepalese children. A survey was performed on 2684 patients (1829 females and 1035 males) ranging in age from 6 to 14 for the presence of supernumerary teeth. For each patient with supernumerary teeth the demographic variables (age and sex), number, location, eruption status, and morphology were recorded. Descriptive statistics were performed. Supernumerary teeth were detected in 46 subjects (1.6%), of which 26 were males and 20 were females with a male : female ratio of 1.3 : 1. The most commonly found supernumerary tooth was mesiodens followed by maxillary premolars, maxillary lateral incisor, and mandibular lateral incisor. Of the 55 supernumerary teeth examined, 58.18% (n = 32) had conical morphology, followed by tuberculate (30.90%, n = 17) and supplemental (10.90%, n = 6) forms. The majority of the supernumerary teeth were erupted (56.36%, n = 31). The prevalence of supernumerary teeth in Nepalese children was found to be 1.6%, the most frequent type being mesiodens. Conical morphology was found to be the most common form of supernumerary tooth.

  8. Dentigerous cyst in a child associated with multiple inverted supernumerary teeth: a rare occurrence.

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    Agrawal, Neeraj K

    2012-01-01

    Dentigerous cysts associated with supernumerary teeth are rare with most of them developing around a mesiodens in the anterior maxilla. Dentigerous cysts from multiple supernumerary teeth, especially with inverted tooth, are rare in other regions of the maxilla. We report a unique case of a dentigerous cyst in a child associated with multiple inverted supernumerary teeth and relevant review of literarature. Dentigerous cyst arising from multiple supernumerary teeth and not anterior maxillary mesiodens is quite uncommon. In a child, such findings associated with inverted tooth are still rare. Such cysts should be managed by excision as soon as possible.

  9. The double electrostatic ion ring experiment: A unique cryogenic electrostatic storage ring for merged ion-beams studies

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    Thomas, R. D.; Schmidt, H. T.; Andler, G.; Bjoerkhage, M.; Blom, M.; Braennholm, L.; Baeckstroem, E.; Danared, H.; Das, S.; Haag, N.; Hallden, P.; Hellberg, F.; Holm, A. I. S.; Johansson, H. A. B.; Kaellberg, A.; Kaellersjoe, G.; Larsson, M.; Leontein, S.; Liljeby, L.; Loefgren, P. [Department of Physics, Stockholm University, SE-106 91 Stockholm (Sweden); and others

    2011-06-15

    We describe the design of a novel type of storage device currently under construction at Stockholm University, Sweden, using purely electrostatic focussing and deflection elements, in which ion beams of opposite charges are confined under extreme high vacuum cryogenic conditions in separate ''rings'' and merged over a common straight section. The construction of this double electrostatic ion ring experiment uniquely allows for studies of interactions between cations and anions at low and well-defined internal temperatures and centre-of-mass collision energies down to about 10 K and 10 meV, respectively. Position sensitive multi-hit detector systems have been extensively tested and proven to work in cryogenic environments and these will be used to measure correlations between reaction products in, for example, electron-transfer processes. The technical advantages of using purely electrostatic ion storage devices over magnetic ones are many, but the most relevant are: electrostatic elements which are more compact and easier to construct; remanent fields, hysteresis, and eddy-currents, which are of concern in magnetic devices, are no longer relevant; and electrical fields required to control the orbit of the ions are not only much easier to create and control than the corresponding magnetic fields, they also set no upper mass limit on the ions that can be stored. These technical differences are a boon to new areas of fundamental experimental research, not only in atomic and molecular physics but also in the boundaries of these fields with chemistry and biology. For examples, studies of interactions with internally cold molecular ions will be particular useful for applications in astrophysics, while studies of solvated ionic clusters will be of relevance to aeronomy and biology.

  10. Phase transfer reagent promoted tandem ring-opening and ring-closing reactions of unique 3-(1-alkynyl) chromones.

    Science.gov (United States)

    Liu, Yang; Jin, Shiyu; Huang, Liping; Hu, Youhong

    2015-05-01

    A phase transfer reagent promoted tandem ring-opening and ring-closing reaction of 3-(1-alkynyl) chromones has been developed. This process remarkably generates functionalized 3-acyl-2-substituted chromones. Interestingly, when 3-(hepta-1,6-diyn-1-yl)chromone derivatives are applied, a novel tetracyclic chromone scaffold can be obtained by a further intramolecular 4 + 2 cyclization.

  11. Supernumerary Jawbone Tooth: Clinical Case

    OpenAIRE

    Rivas Gutiérrez, Jesús; Carlos Sánchez, María Dolores

    2016-01-01

    Introduction: supernumerary teeth are dental development anomalies, alsoknown as hyperdontia or extra teeth. Their prevalence ranges between 0.3% and 3.8%.Their morphology may be normal or dismorphic and are associated to the etiology ofocclusal alterations. It is important to make an early diagnostic through a radiographicalstudy. Case presentation:this article presents a clinical case of a supernumerary tooth thatcaused rotation and crowding of the anterior bottom teeth, which was addressed...

  12. Supernumerary teeth "mesiodens". Case report.

    Science.gov (United States)

    Itro, A; Difalco, P

    2003-09-01

    The supernumerary tooth is an anomaly of dental eruption that is not rare to find in the clinical practice. Among the supernumerary teeth the "mesiodens" is most frequent. The mesiodens is found in the region of the superior central incisors and it can be the cause of many complications. The aim of this work is the description of a rare symptomatic case of mesiodens and the diagnostic and therapeutic strategies to adopt when this dental anomaly occurs. In particular the authors suggest making radiographic examinations only in the family of patients with dental anomalies of number, thinking that the incidence of such anomalies is too low to justify mass radiographic examinations.

  13. Late Developing Supernumeraries in a Case of Nonsyndromic Multiple Supernumerary Teeth

    Directory of Open Access Journals (Sweden)

    Mine Bozkurt

    2015-01-01

    Full Text Available Objective. This case report presents 3-year follow-up of a case of nonsyndromic multiple supernumerary teeth (NSMST with 11 supernumerary teeth, 2 of which showed subsequent formation. Case Report. A 10-year-old girl was referred to the dental clinic with the chief complaint of delayed eruption. Radiographic examination showed 9 retained supernumerary teeth. The treatment plan consisted of extraction of the supernumerary teeth and associated primary teeth in order to allow the permanent teeth to erupt. After 2 years of follow-up, 2 additional supernumerary teeth were observed. Conclusion. Regular follow-up for late forming supernumeraries is crucial for NSMST cases.

  14. The uniqueness of the invariant polarisation-tensor field for spin-1 particles in storage rings

    Energy Technology Data Exchange (ETDEWEB)

    Barber, D.P.; Vogt, M. [DESY Hamburg (Germany); Kling, A. [Osnabrueck Univ. of Applied Sciences, Lingen (Germany). Inst. of Dual Cooperative Studies

    2015-10-15

    We argue that the invariant tensor field introduced in an earlier paper (D.P. Barber, DESY Report 15-181 and arXiv:1510.04936 /2015) is unique under the condition that the invariant spin field is unique, and thereby complete that part of the discussion in that paper.

  15. Supernumerary teeth in non-syndromic patients

    Energy Technology Data Exchange (ETDEWEB)

    Mali, Santosh; Karjodkar, Freny Rashmiraj; Sontakke, Subodh; Sansare, Kaustubh [Nair Hospital Dental College, Maharashtra (India)

    2012-03-15

    Hyperdontia or supernumerary teeth without associated syndrome is a rare phenomenon, as supernumerary teeth are usually associated with cleft lip and palate or other syndromes such as Gardner's syndrome, cleidocranial dysplasia, and so on. Five patients with supernumerary teeth visited our department. They had no familial history or other pathology, certain treatment protocols was modified due to the presence of supernumerary teeth. Non-syndromic supernumerary teeth, if asymptomatic, need to have periodical radiographic observation. If they showed no variation as they impacted in the jaw, careful examination is necessary because they may develop into pathological status such as dentigerous cysts. The importance of a precise clinical history and radiographic examination for patients with multiple supernumerary teeth should be emphasized.

  16. Late Developing Supernumeraries in a Case of Nonsyndromic Multiple Supernumerary Teeth

    OpenAIRE

    Mine Bozkurt; Tugba Bezgin; Ayşegül Tüzüner Öncül; Rukiye Göçer; Şaziye Sarı

    2015-01-01

    Objective. This case report presents 3-year follow-up of a case of nonsyndromic multiple supernumerary teeth (NSMST) with 11 supernumerary teeth, 2 of which showed subsequent formation. Case Report. A 10-year-old girl was referred to the dental clinic with the chief complaint of delayed eruption. Radiographic examination showed 9 retained supernumerary teeth. The treatment plan consisted of extraction of the supernumerary teeth and associated primary teeth in order to allow the permanent tee...

  17. Fibroadenoma in axillary supernumerary breast: case report

    OpenAIRE

    Délio Marques Conde; Renato Zocchio Torresan; Eiji Kashimoto; Luiz Eduardo Campos de Carvalho; Cássio Cardoso Filho

    2005-01-01

    CONTEXT: Supernumerary breast tissue may be affected by the same diseases and alterations that compromise topical breast tissue. Nevertheless, reports of fibroadenoma in supernumerary breast tissue in the axillae are rare. OBJECTIVE: To describe a case of fibroadenoma in an axillary supernumerary breast. DESIGN: Case report. CASE REPORT: A 39-year-old woman was referred to the gynecology and obstetrics outpatient clinic at Hospital Estadual Sumaré, complaining of bilateral axillary masses. Th...

  18. Surgical management of multiple supernumerary teeth and an impacted maxillary permanent central incisor.

    Science.gov (United States)

    Rallan, Mandeep; Rallan, Neelakshi Singh; Goswami, Mousumi; Rawat, Kamini

    2013-05-22

    Hyperdontia is the condition of having supernumerary teeth, or teeth which appear in addition to the regular number of teeth. It is a developmental anomaly and has been argued to arise from multiple aetiologies. The most common site is the maxillary incisor region; but the prevalence of more than three teeth supernumerary tooth is less than 1%. A case of 13 year male patient is reported with a multiple impacted supernumerary tooth in maxillary anterior region hindering the eruption of right permanent central incisor. The supernumerary tooth was treated via surgical approach followed by an interim prosthesis for permanent central incisor which later on erupted in due course of time. Background Supernumerary teeth may be defined as any teeth or tooth substance in excess of the usual configuration of 20 deciduous and 32 permanent teeth. The presence of supernumerary teeth in the premaxillary region often poses unique diagnostic and managerial concerns for the practitioner. Rarely is the surplus number compensated by an absence or deficiency of other teeth. Therefore, the dysfunctional nature of supernumerary teeth and their ability to create a variety of pathological disturbances in the normal eruption and position of adjacent teeth warrants their early detection and prudent management. Approximately 76-86% of cases represent single-tooth hyperdontia, with two supernumerary teeth noted in 12-23% and three or more extra teeth noted in less than 1% of cases. Multiple supernumerary teeth are also associated with many syndromes like cleidocranial dysplasia and Gardner’s syndrome etc. However, it is rare to find multiple supernumeraries in individuals with no other associated disease or syndrome. In such cases, the maxillary anterior region is the common site of occurrence. The exact aetiology is not clearly understood. The supernumerary teeth result from any disturbance in the initiation and proliferation stages of odontogenesis. There are several theories regarding the

  19. Ring Opening Reactions through C-O Bond Cleavage Uniquely Adding Chemical Functionality to Boron Subphthalocyanine

    Directory of Open Access Journals (Sweden)

    Catherine Bonnier

    2015-10-01

    Full Text Available We are reporting the unexpected reaction between bromo-boron subphthalocyanine (Br-BsubPc and THF, 1,4-dioxane or γ-butyrolactone that results in the ring opening of the solvent and its addition into the BsubPc moiety. Under heating, the endocyclic C-O bond of the solvent is cleaved and the corresponding bromoalkoxy-BsubPc derivative is obtained. These novel alkoxy-BsubPc derivatives have remaining alkyl-bromides suitable for further functionalization. The alkoxy-BsubPcs maintain the characteristic strongly absorption in visible spectrum and their fluorescence quantum yields.

  20. Fibroadenoma in axillary supernumerary breast: case report

    Directory of Open Access Journals (Sweden)

    Délio Marques Conde

    Full Text Available CONTEXT: Supernumerary breast tissue may be affected by the same diseases and alterations that compromise topical breast tissue. Nevertheless, reports of fibroadenoma in supernumerary breast tissue in the axillae are rare. OBJECTIVE: To describe a case of fibroadenoma in an axillary supernumerary breast. DESIGN: Case report. CASE REPORT: A 39-year-old woman was referred to the gynecology and obstetrics outpatient clinic at Hospital Estadual Sumaré, complaining of bilateral axillary masses. The patient reported cosmetic problems and local pain and discomfort. On physical examination, alterations compatible with bilateral axillary accessory breasts, without palpable nodules, were observed. Supplementary examinations (mammography and ultrasonography revealed a 1.1 cm mass in the right axillary breast. The patient underwent resection of the supernumerary breasts and histopathological examination revealed fibroadenoma of the right axillary breast tissue.

  1. Insights into Ubiquitination from the Unique Clamp-like Binding of the RING E3 AO7 to the E2 UbcH5B*

    Science.gov (United States)

    Li, Shengjian; Liang, Yu-He; Mariano, Jennifer; Metzger, Meredith B.; Stringer, Daniel K.; Hristova, Ventzislava A.; Li, Jess; Randazzo, Paul A.; Tsai, Yien Che; Ji, Xinhua; Weissman, Allan M.

    2015-01-01

    RING proteins constitute the largest class of E3 ubiquitin ligases. Unlike most RINGs, AO7 (RNF25) binds the E2 ubiquitin-conjugating enzyme, UbcH5B (UBE2D2), with strikingly high affinity. We have defined, by co-crystallization, the distinctive means by which AO7 binds UbcH5B. AO7 contains a structurally unique UbcH5B binding region (U5BR) that is connected by an 11-amino acid linker to its RING domain, forming a clamp surrounding the E2. The U5BR interacts extensively with a region of UbcH5B that is distinct from both the active site and the RING-interacting region, referred to as the backside of the E2. An apparent paradox is that the high-affinity binding of the AO7 clamp to UbcH5B, which is dependent on the U5BR, decreases the rate of ubiquitination. We establish that this is a consequence of blocking the stimulatory, non-covalent, binding of ubiquitin to the backside of UbcH5B. Interestingly, when non-covalent backside ubiquitin binding cannot occur, the AO7 clamp now enhances the rate of ubiquitination. The high-affinity binding of the AO7 clamp to UbcH5B has also allowed for the co-crystallization of previously described and functionally important RING mutants at the RING-E2 interface. We show that mutations having marked effects on function only minimally affect the intermolecular interactions between the AO7 RING and UbcH5B, establishing a high degree of complexity in activation through the RING-E2 interface. PMID:26475854

  2. The management of premolar supernumeraries in three orthodontic cases.

    LENUS (Irish Health Repository)

    McNamara, C M

    1997-01-01

    This paper reviews the incidence, etiology and location of supernumerary teeth with emphasis on premolar supernumeraries and examines the management of supernumerary premolars of three patients undergoing orthodontics. These cases demonstrate that the management of premolars is assessed individually and treatments based on potential complications, which may occur during the orthodontic and surgical management of the dentition. Progress and posttreatment radiographs are recommended for the assessment of late forming supernumerary teeth.

  3. Prevalence, etiology, diagnosis, treatment and complications of supernumerary teeth

    OpenAIRE

    Ata-Ali Mahmud, Fadi; Ata-Ali Mahmud, Francisco Javier; Peñarrocha Oltra, David; Peñarrocha Diago, Miguel

    2014-01-01

    The aim of this article was to review the literature on supernumerary teeth, analyzing their prevalence, etiology, diagnosis, treatment and possible complications. An electronic search was made in the Pubmed-Medline database up to January 2014 using the key search terms “multiple supernumerary teeth” (n=279), “prevalence supernumerary teeth” (n=361), and “supernumerary teeth” (n=2412). In addition to the articles initially identified, others were included in the review proceeding from a manua...

  4. Supernumerary teeth: Report of four unusual cases

    Directory of Open Access Journals (Sweden)

    Arun Kumar

    2012-01-01

    Full Text Available Supernumerary tooth denotes duplication of tooth in the normal series. It is a developmental anomaly and has been argued to arise from multiple etiologies. These teeth may remain embedded in the alveolar bone or can erupt into the oral cavity. The supernumerary tooth might cause esthetic and/or functional problems, especially if it is situated in the maxillary anterior region. Complications reported were delayed or prevented eruption of succedaneous teeth, displacement or rotation, crowding of the affected region, abnormal diastema, dilacerations, cystic formation, and sometime eruption into the nasal cavity. In this case report, four unusual cases of supernumerary teeth that resulted in varying degrees of disturbances in permanent dentition are presented. Conservative surgical intervention and light orthodontic forces were used to bring the teeth into normal position with minimal disturbance to the surrounding oral structures.

  5. Supernumerary teeth: Report of four unusual cases.

    Science.gov (United States)

    Kumar, Arun; Namdev, Ritu; Bakshi, Lokesh; Dutta, Samir

    2012-04-01

    Supernumerary tooth denotes duplication of tooth in the normal series. It is a developmental anomaly and has been argued to arise from multiple etiologies. These teeth may remain embedded in the alveolar bone or can erupt into the oral cavity. The supernumerary tooth might cause esthetic and/or functional problems, especially if it is situated in the maxillary anterior region. Complications reported were delayed or prevented eruption of succedaneous teeth, displacement or rotation, crowding of the affected region, abnormal diastema, dilacerations, cystic formation, and sometime eruption into the nasal cavity. In this case report, four unusual cases of supernumerary teeth that resulted in varying degrees of disturbances in permanent dentition are presented. Conservative surgical intervention and light orthodontic forces were used to bring the teeth into normal position with minimal disturbance to the surrounding oral structures.

  6. Laparoscopic management of tumor in supernumerary ovary

    Science.gov (United States)

    Prakash, Ved; Kant, Anita; Parashar, Abha; Rani, Uma

    2016-01-01

    Laparoscopic management of most of the adnexal masses has become feasible in the present era of advancing endoscopic techniques. A postmenopausal lady presented with lump in the abdomen, appeared to be a solid ovarian mass on ultrasound, and magnetic resonance imaging. On laparoscopy, both the ovaries were normal and the mass was not connected to uterus or adnexa. The mass was removed and histopathology confirmed it to be ovarian tissue thus confirming it to be a tumor in a supernumerary ovary. Examples of supernumerary ovary are among the rarest of gynecological abnormalities. PMID:27134478

  7. Laparoscopic management of tumor in supernumerary ovary

    Directory of Open Access Journals (Sweden)

    Ved Prakash

    2016-01-01

    Full Text Available Laparoscopic management of most of the adnexal masses has become feasible in the present era of advancing endoscopic techniques. A postmenopausal lady presented with lump in the abdomen, appeared to be a solid ovarian mass on ultrasound, and magnetic resonance imaging. On laparoscopy, both the ovaries were normal and the mass was not connected to uterus or adnexa. The mass was removed and histopathology confirmed it to be ovarian tissue thus confirming it to be a tumor in a supernumerary ovary. Examples of supernumerary ovary are among the rarest of gynecological abnormalities.

  8. Supernumerary Teeth in Indian Children: A Survey of 300 Cases

    Directory of Open Access Journals (Sweden)

    Amita Sharma

    2012-01-01

    Full Text Available The aim of this investigation was to study children with supernumerary teeth who visited the Department of Pedodontics and Preventive Dentistry, Government Dental College and Hospital, Rohtak, Haryana, India. Only children with supernumerary teeth were included in the study while patients having supernumerary teeth with associated syndromes were excluded. Supernumeraries were detected by clinical and radiographic examination. The results indicated that males were affected more than females with a sex ratio of 2.9 : 1. Single supernumerary tooth was seen in 79% of the patients, 20% had double, and 1% had three or more supernumeraries. Premaxillary supernumeraries accounted for 93.8% of the cases. Conical shaped supernumerary teeth were the most common type (59.7%. Majority of supernumeraries remained unerupted (65%. Fusion of supernumerary tooth with a regular tooth was observed in 4% of the patients. Talon cusp, an associated dental anomaly, was seen in 5% of the cases. Simultaneous hypodontia occurred in 2.3% of patients with supernumeraries.

  9. The genome of Nectria haematococca: contribution of supernumerary chromosomes to gene expansion

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, J.J.; Rounsley, S.D.; Rodriguez-Carres, M.; Kuo, A.; Wasmann, C.c.; Grimwood, J.; Schmutz, J.; Taga, M.; White, G.J.; Zhuo, S.; Schwartz, D.C.; Freitag, M.; Ma, L.-J.; Danchin, E.G.J.; Henrissat, B.; Cutinho, P.M.; Nelson, D.R.; Straney, D.; Napoli, C.A.; Baker, B.M.; Gribskov, M.; Rep, M.; Kroken, S.; Molnar, I.; Rensing, C.; Kennell, J.C.; Zamora, J.; Farman, M.L.; Selker, E.U.; Salamov, A.; Shapiro, H.; Pangilinan, J.; Lindquist, E.; Lamers, C.; Grigoriev, I.V.; Geiser, D.M.; Covert, S.F.; Temporini, S.; VanEtten, H.D.

    2009-04-20

    The ascomycetous fungus Nectria haematococca, (asexual name Fusarium solani), is a member of a group of .50 species known as the"Fusarium solani species complex". Members of this complex have diverse biological properties including the ability to cause disease on .100 genera of plants and opportunistic infections in humans. The current research analyzed the most extensively studied member of this complex, N. haematococca mating population VI (MPVI). Several genes controlling the ability of individual isolates of this species to colonize specific habitats are located on supernumerary chromosomes. Optical mapping revealed that the sequenced isolate has 17 chromosomes ranging from 530 kb to 6.52 Mb and that the physical size of the genome, 54.43 Mb, and the number of predicted genes, 15,707, are among the largest reported for ascomycetes. Two classes of genes have contributed to gene expansion: specific genes that are not found in other fungi including its closest sequenced relative, Fusarium graminearum; and genes that commonly occur as single copies in other fungi but are present as multiple copies in N. haematococca MPVI. Some of these additional genes appear to have resulted from gene duplication events, while others may have been acquired through horizontal gene transfer. The supernumerary nature of three chromosomes, 14, 15, and 17, was confirmed by their absence in pulsed field gel electrophoresis experiments of some isolates and by demonstrating that these isolates lacked chromosome-specific sequences found on the ends of these chromosomes. These supernumerary chromosomes contain more repeat sequences, are enriched in unique and duplicated genes, and have a lower G+C content in comparison to the other chromosomes. Although the origin(s) of the extra genes and the supernumerary chromosomes is not known, the gene expansion and its large genome size are consistent with this species' diverse range of habitats. Furthermore, the presence of unique genes on

  10. The genome of Nectria haematococca: contribution of supernumerary chromosomes to gene expansion.

    Directory of Open Access Journals (Sweden)

    Jeffrey J Coleman

    2009-08-01

    Full Text Available The ascomycetous fungus Nectria haematococca, (asexual name Fusarium solani, is a member of a group of >50 species known as the "Fusarium solani species complex". Members of this complex have diverse biological properties including the ability to cause disease on >100 genera of plants and opportunistic infections in humans. The current research analyzed the most extensively studied member of this complex, N. haematococca mating population VI (MPVI. Several genes controlling the ability of individual isolates of this species to colonize specific habitats are located on supernumerary chromosomes. Optical mapping revealed that the sequenced isolate has 17 chromosomes ranging from 530 kb to 6.52 Mb and that the physical size of the genome, 54.43 Mb, and the number of predicted genes, 15,707, are among the largest reported for ascomycetes. Two classes of genes have contributed to gene expansion: specific genes that are not found in other fungi including its closest sequenced relative, Fusarium graminearum; and genes that commonly occur as single copies in other fungi but are present as multiple copies in N. haematococca MPVI. Some of these additional genes appear to have resulted from gene duplication events, while others may have been acquired through horizontal gene transfer. The supernumerary nature of three chromosomes, 14, 15, and 17, was confirmed by their absence in pulsed field gel electrophoresis experiments of some isolates and by demonstrating that these isolates lacked chromosome-specific sequences found on the ends of these chromosomes. These supernumerary chromosomes contain more repeat sequences, are enriched in unique and duplicated genes, and have a lower G+C content in comparison to the other chromosomes. Although the origin(s of the extra genes and the supernumerary chromosomes is not known, the gene expansion and its large genome size are consistent with this species' diverse range of habitats. Furthermore, the presence of unique

  11. Four miniature kidneys: supernumerary kidney and multiple organ system anomalies.

    Science.gov (United States)

    Afrouzian, Marjan; Sonstein, Joseph; Dadfarnia, Tahereh; Sreshta, J Nicholas; Hawkins, Hal K

    2014-05-01

    More than 350 years after Martius's first reported case in 1656, supernumerary kidney (SNK) continues to fascinate the world of medicine, generating new ideas in the domain of embryogenesis. Association of a normal kidney with a second or third ipsilateral smaller kidney is an extremely rare anomaly with only a total of 81 cases reported until today. We are reporting a case of SNK, clinically diagnosed as right hydronephrosis, associated with an ipsilateral ectopic ureter, a contralateral partially duplicated ureter, and a multiseptate gallbladder. Pathologic examination of the nephrectomy revealed 4 miniature kidneys, joining a dilated ureter through 4 separate conduits. Our patient is the first reported case of SNK with absent ipsilateral normal kidney, presence of more than 3 kidneys on 1 side, and associated anomaly in the gallbladder. This case represents a unique combination of rarities, suggesting insights in the domain of molecular embryology.

  12. Non-syndromic supernumerary teeth: report of a case with 6 supernumerary teeth

    Directory of Open Access Journals (Sweden)

    Taghibakhsh M

    2011-02-01

    Full Text Available "nBackground and Aims: Multiple supernumerary teeth are rare and often found in association with syndromes such as Gardner, Cleidocranial dysplasia and cleft lip and palate, with a much less chance for isolated"nnon-syndromic cases. The aim of this study was to report a case with 6 supernumerary teeth without syndromic association."nCase Report: The patient was a 33 year-old female, referred to oral diseases and diagnosis department with chief complaint of sensitivity to cold and hot food in right upper premolar region. Oral examination revealed 5 erupted lingually supernumerary teeth (four in mandibular and one in maxillary premolar region, respectively. Further panoramic radiography clarified an extra impacted tooth in the palatal region of left premolar maxillary area. All extra teeth had been appeared since the age of 17 during one year, as the patient claimed. Medical history and thorough clinical and paraclinical examinations were not significant except for the hypothyroidism, since 5 years ago. No other family member noticed to be the case. Based on our findings, a diagnosis of non-syndromic multiple supernumerary teeth was established."nConclusion: A thorough examination of each patient presented with supernumerary teeth, including panoramic and intraoral radiographic images may provide valuable information regarding accompanying syndromes and unerupted teeth. Early diagnosis is an essential step for orthodontic or surgical decisions making, preventing or avoiding worsening complications such as malocclusion, adjacent normal teeth delayed eruption or rotation, diasthema, cystic lesions and resorption of contiguous teeth.

  13. Canaliculitis in supernumerary puncta and canaliculi

    Directory of Open Access Journals (Sweden)

    Ku Chui Yong

    2011-08-01

    Full Text Available We report the first case of supernumerary puncta and canaliculi presented with canaliculitis. A-59 year-old gentleman presented with painful swelling of the left lower lid for a week, which was associated with epiphora. The swelling was confined to the nasal aspect of the left lower lid (0.5¥0.5 mm with inflamed overlying skin. Two puncta (0.5 mm apart were noted. The outer punctum at the normal anatomical position was a cul-de-sac while the inner punctum it the caruncle was patent. We described the embryology leading to supernumerary puncta and canaliculi to explain the paradoxical patency of the abnormally located punctum as well as the pathomechanism leading to canaliculitis. The patient was treated with oral cloxacillin 500 mg, 6 hourly for 5 days; the cellulitis subsided after three days.

  14. Supernumerary teeth: Review of literature and decision support system

    Directory of Open Access Journals (Sweden)

    Deepti Amarlal

    2013-01-01

    Full Text Available Supernumerary teeth are those which are additional or in excess of the normal number. They can be either single or multiple, unilateral or bilateral and can be present anywhere in the dental arch with predilection for the premaxilla. Supernumerary teeth are mostly classified on position and form. Timing of surgical intervention of supernumerary teeth has been controversial with various authors having different opinions. Hence a new decision support system is put forward which can help in the treatment planning of supernumerary teeth.

  15. The effects of impacted premaxillary supernumerary teeth on permanent incisors

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Yun Hoa; Kim, Ji Yeon; Cho, Bong Hae [School of Dentistry, Pusan National University, Yangsan (Korea, Republic of)

    2016-12-15

    The aim of this study was to examine the radiographic features associated with impacted premaxillary supernumerary teeth, to determine the relationship between their characteristics and their effects on permanent incisors, and to investigate the types of orthodontic treatment that patients received after the extraction of impacted supernumerary teeth. The clinical records and radiographs of 193 patients whose impacted premaxillary supernumerary teeth were removed were retrospectively reviewed, and 241 impacted supernumerary teeth were examined. Cone-beam computed tomographic images and panoramic radiographs were examined to determine the number, location, sagittal position, orientation, and morphology of the supernumerary teeth. Their effects on permanent incisors and the orthodontic treatment received by patients after the extraction of the supernumeraries were also investigated. Supernumerary teeth were most frequently observed in the central incisor region, in the palatal position, in the inverted orientation, and were most commonly conical in shape. The most common complication was median diastema, followed by displacement and delayed eruption of the adjacent incisors. Ten (71.4%) of the 14 odontomas showed delayed eruption of the adjacent incisors. Displacement of the incisors was more frequently observed in association with supernumerary teeth with tuberculate or supplemental shapes. Orthodontic traction was most frequently performed after the removal of odontomas. In 32 cases (13.3%), permanent incisors erupted after the orthodontic creation of sufficient space. Median diastema was most common complication. The delayed eruption of incisors was common in supernumerary teeth with a vertical orientation and an odontoma shape.

  16. The effects of impacted premaxillary supernumerary teeth on permanent incisors

    Science.gov (United States)

    Jung, Yun-Hoa; Kim, Ji-Yeon

    2016-01-01

    Purpose The aim of this study was to examine the radiographic features associated with impacted premaxillary supernumerary teeth, to determine the relationship between their characteristics and their effects on permanent incisors, and to investigate the types of orthodontic treatment that patients received after the extraction of impacted supernumerary teeth. Materials and Methods The clinical records and radiographs of 193 patients whose impacted premaxillary supernumerary teeth were removed were retrospectively reviewed, and 241 impacted supernumerary teeth were examined. Cone-beam computed tomographic images and panoramic radiographs were examined to determine the number, location, sagittal position, orientation, and morphology of the supernumerary teeth. Their effects on permanent incisors and the orthodontic treatment received by patients after the extraction of the supernumeraries were also investigated. Results Supernumerary teeth were most frequently observed in the central incisor region, in the palatal position, in the inverted orientation, and were most commonly conical in shape. The most common complication was median diastema, followed by displacement and delayed eruption of the adjacent incisors. Ten (71.4%) of the 14 odontomas showed delayed eruption of the adjacent incisors. Displacement of the incisors was more frequently observed in association with supernumerary teeth with tuberculate or supplemental shapes. Orthodontic traction was most frequently performed after the removal of odontomas. In 32 cases (13.3%), permanent incisors erupted after the orthodontic creation of sufficient space. Conclusion Median diastema was most common complication. The delayed eruption of incisors was common in supernumerary teeth with a vertical orientation and an odontoma shape. PMID:28035303

  17. Bilateral supernumerary teeth in deciduous dentition-a rarity.

    Science.gov (United States)

    Acharya, Sonu; Ghosh, Chiranjit; Mondal, Pradeep Kumar

    2014-05-01

    Supernumerary teeth are considered as one of the most significant dental anomalies during the primary and early mixed dentition stages. They are of great concern to the dentists and parents because of the eruption, occlusal, and esthetic problems they can cause. Supernumerary teeth occur more frequently in the permanent dentition but rarely in primary dentition and more often seen in males. A supernumerary tooth in the primary dentition can cause ectopic or delayed eruption of permanent central incisors which will further alter occlusion and may compromise esthetics and formation of dentigerous cysts. Here we discuss a case of bilateral supernumerary teeth in deciduous dentition in a female child.

  18. Impacted supernumerary tooth in coronoid process: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Park, Won Se; Lee, Je Ho; Park, Hyok; Jung, Ho Gul; Kim, Kee Deog [Yonsei University College of Dentistry, Seoul (Korea, Republic of)

    2010-06-15

    Impaction of tooth is a situation in which an unerupted tooth is wedged against another tooth or teeth or otherwise located so that it cannot erupt normally. The supernumerary tooth is also called as hyperdontia and defined as the condition of having additional tooth to the regular number of teeth. The most common supernumerary tooth is a mesiodens, which is a mal-formed, peg-like tooth that occurs between the maxillary incisors. The supernumerary tooth is commonly impacted but they are frequently impacted on maxilla. Ectopic impaction of supernumerary tooth on mandibular condyle, coronoid process, ascending ramus, and pterygomandibular space is very rare condition. In this case, we report a case of impacted supernumerary tooth on mandibular sigmoid notch without definite pathologic change.

  19. Bilaterally impacted mandibular supernumerary premolars associated with unusual clinical complications

    Directory of Open Access Journals (Sweden)

    Zameer Pasha

    2013-01-01

    Full Text Available Supernumerary teeth are extra teeth in comparison to the normal dentition. Their prevalence varies between 0.1% and 3.8%. Supernumeraries are more common in permanent dentition and its incidence is higher in maxillary incisor region, followed by maxillary third molar and mandibular molar, premolar, canine, and lateral incisor. The prevalence of supernumerary premolars is between 0.075-0.26%, and they may occur in single or multiple numbers Bilateral occurrence is uncommon and large percentage of supernumerary premolars remains impacted, unerupted, and usually asymptomatic; radiograph plays an important role in diagnosis of these. The present paper reports a case of bilaterally impacted completely developed supernumerary premolars associated with common clinical complication in unusual manner along with taurodontism of the upper and lower molars.

  20. Multilobed mesiodens: a supernumerary tooth with unusual morphology.

    Science.gov (United States)

    Dave, Bhavna; Patel, Jalark; Swadas, Milan; Mallikarjuna, Rachappa

    2013-02-06

    An 8-year-old boy came with a chief complaint of an abnormally shaped tooth situated in upper front teeth region. On examination a supernumerary tooth with multiple lobes was present palatally to the maxillary right permanent central incisor. The morphology of the tooth crown was found to be unusual due to the presence of five lobes in the crown portion. Because of the supernumerary tooth, the permanent right central incisor was displaced labially. Radiographic examination showed a completely formed supernumerary tooth with dilacerated root. On the basis of clinical and radiographic examination, the supernumerary tooth was diagnosed as multilobed mesiodens. Since patient expressed dissatisfaction with the presence of supernumerary tooth, it was decided to extract this mesiodens followed by orthodontic treatment for alignment of labially placed maxillary right permanent central incisor.

  1. Supernumerary and supplemental teeth: case report.

    Science.gov (United States)

    Lo Giudice, G; Nigrone, V; Longo, A; Cicciù, M

    2008-06-01

    This is to report the case of a ten year old child affected by a numeric dental anomaly showing the pathologic condition characterised by the simultaneous presence of supernumerary and supplemental teeth. The anomaly was analysed to plan the best surgical and orthodontic treatments. Dental history, clinical and instrumental examinations were made to perform a correct orthodontic examination and diagnosis. A young patient was affected by numeric dental anomaly in the upper jaw. We observed a high number of teeth, specifically two normally formed supplemental lateral permanent incisors and an unerupted mesiodens placed between the upper central incisors. Firstly, the supplemental lateral teeth were extracted. This surgical therapy and the application of a space maintainer were made to permit the eruption of the permanent canines. Then the mesiodens also underwent surgical treatment (i.e. extraction). Eventually, physiologic eruption of permanent teeth was allowed by the planned surgical-orthodontic treatment. Aim of the surgical-orthodontic treatment was extraction of the unerupted supernumerary teeth to obtain the physiologic eruption of the permanent ones. Orthodontic treatment is important to solve malocclusions and maintaining the space for the eruption of permanent teeth. Aesthetics and function are two important parameters in modern dentistry. All clinicians should try to make a correct and rational diagnosis for both simple and complex dental pathologies. Particularly in young children, invasive and surgical disinclusive techniques can be substituted by interceptive orthodontic treatments.

  2. Graphene with vacancies: Supernumerary zero modes

    Science.gov (United States)

    Weik, Norman; Schindler, Johannes; Bera, Soumya; Solomon, Gemma C.; Evers, Ferdinand

    2016-08-01

    The density of states ϱ (E ) of graphene is investigated within the tight-binding (Hückel) approximation in the presence of vacancies. They introduce a nonvanishing density of zero modes nzm that act as midgap states, ϱ (E ) =nzmδ (E ) +smooth . As is well known, the actual number of zero modes per sample can, in principle, exceed the sublattice imbalance, Nzm≥|NA-NB| , where NA,NB denote the number of carbon atoms in each sublattice. In this paper, we establish a stronger relation that is valid in the thermodynamic limit and that involves the concentration of zero modes, nzm>|cA-cB| , where cA and cB denote the concentration of vacancies per sublattice; in particular, nzm is nonvanishing even in the case of balanced disorder, NA/NB=1 . Adopting terminology from benzoid graph theory, the excess modes associated with the current carrying backbone (percolation cluster) are called supernumerary. In the simplest cases, such modes can be associated with structural elements such as carbon atoms connected with a single bond, only. Our result suggests that the continuum limit of bipartite hopping models supports nontrivial "supernumerary" terms that escape the present continuum descriptions.

  3. Small supernumerary marker chromosomes and their correlation with specific syndromes

    Science.gov (United States)

    Jafari-Ghahfarokhi, Hamideh; Moradi-Chaleshtori, Maryam; Liehr, Thomas; Hashemzadeh-Chaleshtori, Morteza; Teimori, Hossein; Ghasemi-Dehkordi, Payam

    2015-01-01

    A small supernumerary marker chromosome (sSMC) is a structurally abnormal chromosome. It is an additional chromosome smaller than one chromosome most often lacking a distinct banding pattern and is rarely identifiable by conventional banding cytogenetic analysis. The origin and composition of an sSMC is recognizable by molecular cytogenetic analysis. These sSMCs are seen in different shapes, including the ring, centric minute, and inverted duplication shapes. The effects of sSMCs on the phenotype depend on factors such as size, genetic content, and the level of the mosaicism. The presence of an sSMC causes partial tris- or tetrasomy, and 70% of the sSMC carriers are clinically normal, while 30% are abnormal in some way. In 70% of the cases the sSMC is de novo, in 20% it is inherited from the mother, and in 10% it is inherited from the father. An sSMC can be causative for specific syndromes such as Emanuel, Pallister-Killian, or cat eye syndromes. There may be more specific sSMC-related syndromes, which may be identified by further investigation. These 10 syndromes can be useful for genetic counseling after further study. PMID:26322288

  4. Clinical management of supernumerary teeth: A report of two cases

    Directory of Open Access Journals (Sweden)

    Mittal M

    2010-09-01

    Full Text Available Supernumerary tooth may closely resemble the teeth of the group to which it belongs, i.e. molars, premolars or anterior teeth, or it may bear little resemblancein size or shape to which it is associated. Many complications can be associated with supernumeraries, like impaction, delayed eruption or ectopic eruption of adjacent teeth, crowding, development of median diastema and eruption into floor of the nasal cavity. This may also cause the formation of follicular cysts with significant bone destruction. Early intervention to remove it is usually required to obtain reasonable alignment and occlusal relationship. This article will present the clinical management of an (i impacted supernumerary tooth impeding the eruption of maxillary central incisor and (ii erupted supernumerary tooth with midline diastema.

  5. Multiple Geminated Supernumerary Premolars: A Rare Case Report

    Directory of Open Access Journals (Sweden)

    Atul Soin

    2015-01-01

    Full Text Available Supernumerary teeth may be defined as any teeth or tooth substance in excess of the usual configuration of 20 deciduous and 32 permanent teeth. Gemination is defined as an attempt by a single tooth bud to divide, with a resultant formation of either a large tooth with a bifid crown or two completely divided teeth throughout the crown and root. Geminated supernumerary premolar is a rarity and the possibility of multiple occurrences is even rarer. An exhaustive review of English literature and a PubMed search conducted using the terms “gemination’’ and “multiple geminated supernumerary” revealed no case of multiple geminated supernumerary premolars. We report a case of multiple geminated supernumerary premolars in a 23-year-old male.

  6. Multiple Geminated Supernumerary Premolars: A Rare Case Report

    Science.gov (United States)

    Soin, Atul; Sharma, Gaurav; Soin, Gayatri; Raina, Anudeep; Mutneja, Puneet; Nagpal, Archna

    2015-01-01

    Supernumerary teeth may be defined as any teeth or tooth substance in excess of the usual configuration of 20 deciduous and 32 permanent teeth. Gemination is defined as an attempt by a single tooth bud to divide, with a resultant formation of either a large tooth with a bifid crown or two completely divided teeth throughout the crown and root. Geminated supernumerary premolar is a rarity and the possibility of multiple occurrences is even rarer. An exhaustive review of English literature and a PubMed search conducted using the terms “gemination” and “multiple geminated supernumerary” revealed no case of multiple geminated supernumerary premolars. We report a case of multiple geminated supernumerary premolars in a 23-year-old male. PMID:26078889

  7. Rare occurrence of bilaterally impacted mandibular supernumerary teeth

    Directory of Open Access Journals (Sweden)

    Vinay Kumar Bhardwaj

    2012-01-01

    Full Text Available Introduction: Supernumerary teeth are present in addition to the normal complement of teeth in permanent or deciduous dentitions. Incidence is high in permanent dentition, affects both the gender. They are more common in males, with the male to female ratio of 2:1. When the supernumerary teeth are causing problems such as, extensive resorption of adjacent teeth, hindering the eruption or malposition of permanent teeth, early surgical intervention is recommended. Case Report: A case of bilaterally impacted supernumerary premolars was reported when an orthopentomograph view was taken which revealed the presence of additional teeth impacted in relation to 35-36 and 45-46. Surgical removal was done as they were resorbing the roots of teeth in their vicinity. Discussion: Literature reports increased occurrence of the supernumeraries in the maxilla but supernumerary premolars are more likely to develop in the mandible. Etiology of supernumerary teeth is ambiguous and is due to following conditions:atavism or reversion, heredity, aberrations during embryologic formation, progress zone, and unified etiologic explanation.

  8. Small Supernumerary Marker Chromosomes in Human Infertility.

    Science.gov (United States)

    Armanet, Narjes; Tosca, Lucie; Brisset, Sophie; Liehr, Thomas; Tachdjian, Gérard

    2015-01-01

    Small supernumerary marker chromosomes (sSMC) are structurally abnormal chromosomes that cannot be unambiguously identified by banding cytogenetics. The objective of this study was to provide an overview of sSMC frequency and characterization in a context of infertility and to review the literature describing sSMC in relation with male and female infertility. Therefore, a systematic literature review on sSMC associated with infertility was conducted by means of a PubMed literature and a sSMC database (http://ssmc-tl.com/sSMC.html) search. A total of 234 patients with infertility were identified as carriers of sSMC. All chromosomes, except chromosomes 10, 19 and the X, were involved in sSMC, and in 72% the sSMC originated from acrocentric chromosomes. Euchromatic imbalances were caused by the presence of sSMC in 30% of the cases. Putative genes have been identified in only 1.2% of sSMC associated with infertility. The implication of sSMC in infertility could be due to a partial trisomy of some genes but also to mechanical effects perturbing meiosis. Further precise molecular and interphase-architecture studies on sSMC are needed in the future to characterize the relationship between this chromosomal anomaly and human infertility.

  9. Paternal isodisomy of chromosome 6 in association with a maternal supernumerary marker chromosome (6)

    Energy Technology Data Exchange (ETDEWEB)

    James, R.S.; Crolla, J.A.; Sitch, F.L. [Salisbury District Hospital, Wiltshire (United Kingdom)] [and others

    1994-09-01

    Uniparental disomy may arise by a number of different mechanisms of aneuploidy correction. A population that has been identified as being at increased risk of aneuploidy are those individuals bearing supernumerary marker chromosomes (SMCs). There have been a number of cases reported of trisomy 21 in association with bi-satellited marker chromosomes have described two individuals with small inv dup (15) markers. One had paternal isodisomy of chromosome 15 and Angelman syndrome. The other had maternal heterodisomy (15) and Prader-Willi syndrome. At the Wessex Regional Genetics Laboratory we have conducted a search for uniparental disomy of the normal homologues of the chromosomes from which SMCs originated. Our study population consists of 39 probands with SMCs originating from a number of different autosomes, including 17 with SMCs of chromosome 15 origin. Using PCR amplification of microsatellite repeat sequences located distal to the regions included in the SMCs we have determined the parental origin of the two normal homologues in each case. We have identified paternal isodisomy of chromosome 6 in a female child with a supernumerary marker ring chromosome 6 in approximately 70% of peripheral blood lymphocytes. The marker was found to be of maternal origin. This is the second case of paternal isodisomy of chromosome 6 to be reported, and the first in association with a SMC resulting in a partial trisomy for a portion of the short arm of chromosome 6. In spite of this, the patient appears to be functioning appropriately for her age.

  10. Non-syndrome associated multiple supernumerary teeth: A report of two cases

    Directory of Open Access Journals (Sweden)

    Nayak Ullal

    2006-05-01

    Full Text Available Multiple supernumerary teeth are usually associated with syndromes. On the contrary, multiple supernumerary teeth without association with any syndromes are very rare. This article presents a report of two cases with multiple supernumerary teeth not associated with any syndrome and emphasizes the routine advice of orthopantomogram whenever a single supernumerary tooth is detected irrespective of whether the patient has any syndrome or not.

  11. Management of fused supernumerary teeth in children using guided tissue regeneration: long-term follow up of 2 cases.

    Science.gov (United States)

    Olsen, Christopher B; Johnston, Timothy; Desai, Mala; Peake, Gregory G

    2002-01-01

    Surgical separation of supernumerary teeth fused to permanent incisor teethhas typically given rise to residual post surgical periodontal defects, induding loss of attachment and deep periodontal pocketing with persistent inflammation. Other complications include devitalisation of the retained tooth section, ankylosis, external and replacement resorption. A unique technique of using guided tissue regeneration has been successfully employed to promote periodontal healing, after 2 cases of surgical removal of a supernumerary tooth fused to a permanent maxillary lateral incisor tooth. In the first case, a 2-stage guided tissue regeneration technique was completed with a nonresorbable Gor-Tex membrane, and was followed up after 9 years. The second case was completed using a resorbable Vicryl membrane, in a single-stage guided tissue regenerative technique; and was followed up after 5 years.

  12. Whole-exome sequencing analysis of supernumerary teeth occurrence in Japanese individuals.

    Science.gov (United States)

    Takahashi, Masahiro; Hosomichi, Kazuyoshi; Yamaguchi, Tetsutaro; Yano, Keisuke; Funatsu, Takahiro; Adel, Mohamed; Haga, Shugo; Maki, Koutaro; Tajima, Atsushi

    2017-01-01

    A common disorder of human dentition is the existence of supernumerary teeth. Impacted supernumerary teeth occur most frequently in the maxillary incisor area and are termed mesiodens. We conducted whole-exome sequencing of non-syndromic Japanese individuals possessing supernumerary teeth to identify genes and/or loci involved in the pathogenesis of the condition.

  13. Late-Developing Supernumerary Premolars: Analysis of Different Therapeutic Approaches

    Directory of Open Access Journals (Sweden)

    Sergio Paduano

    2016-01-01

    Full Text Available This case series describes the different potential approaches to late-developing supernumerary premolars (LDSP. LDSP are supernumerary teeth (ST formed after the eruption of the permanent dentition; usually they develop in the premolar region of the upper and lower jaw. The choice to extract or to monitor the LDSP depends on many factors and has to be carefully planned due to the several risks that either the monitoring or the extraction could provoke. These four cases of LDSP showed different treatment plan alternatives derived from a scrupulous assessment of the clinical and radiographic information.

  14. Supernumerary Teeth in Primary Dentition and Early Intervention: A Series of Case Reports

    Science.gov (United States)

    Bahadure, Rakesh N.; Thosar, Nilima; Jain, Eesha S.; Kharabe, Vidhi; Gaikwad, Rahul

    2012-01-01

    Supernumerary teeth are considered as one of the most significant dental anomalies during the primary and early mixed dentition stages. They are of great concern to the dentists and parents because of the eruption, occlusal, and esthetic problems they can cause. Supernumerary teeth occur more frequently in the permanent dentition but rarely in primary dentition. Mesiodens is the most common type of supernumerary teeth but rarely seen in lower arch. Early recognition and diagnosis of supernumerary teeth is important to prevent further complications in permanent dentition. Four cases of supernumerary teeth with mesiodens in upper and lower arch in primary dentition and their management have been discussed. PMID:22888456

  15. Supernumerary Teeth in Primary Dentition and Early Intervention: A Series of Case Reports

    Directory of Open Access Journals (Sweden)

    Rakesh N. Bahadure

    2012-01-01

    Full Text Available Supernumerary teeth are considered as one of the most significant dental anomalies during the primary and early mixed dentition stages. They are of great concern to the dentists and parents because of the eruption, occlusal, and esthetic problems they can cause. Supernumerary teeth occur more frequently in the permanent dentition but rarely in primary dentition. Mesiodens is the most common type of supernumerary teeth but rarely seen in lower arch. Early recognition and diagnosis of supernumerary teeth is important to prevent further complications in permanent dentition. Four cases of supernumerary teeth with mesiodens in upper and lower arch in primary dentition and their management have been discussed.

  16. Supernumerary teeth in primary dentition and early intervention: a series of case reports.

    Science.gov (United States)

    Bahadure, Rakesh N; Thosar, Nilima; Jain, Eesha S; Kharabe, Vidhi; Gaikwad, Rahul

    2012-01-01

    Supernumerary teeth are considered as one of the most significant dental anomalies during the primary and early mixed dentition stages. They are of great concern to the dentists and parents because of the eruption, occlusal, and esthetic problems they can cause. Supernumerary teeth occur more frequently in the permanent dentition but rarely in primary dentition. Mesiodens is the most common type of supernumerary teeth but rarely seen in lower arch. Early recognition and diagnosis of supernumerary teeth is important to prevent further complications in permanent dentition. Four cases of supernumerary teeth with mesiodens in upper and lower arch in primary dentition and their management have been discussed.

  17. Metabolism of steroidal lactones by the fungus Corynespora cassiicola CBS 161.60 results in a mechanistically unique intramolecular ring-D cyclization resulting in C-14 spiro-lactones.

    Science.gov (United States)

    Hunter, A Christy; Oni, Yewande Inatimi; Dodd, Howard T; Raftery, James; Gardiner, John M; Uttley, Megan

    2017-09-01

    The fungus Corynespora cassiicola metabolises exogenous steroids in a unique and highly specific manner. Central to this, is the ability of this organism to functionalise substrates (androgens, progestogens) at the highly stereochemically hindered 8β-position of the steroid nucleus. A recent study has identified that 8β-hydroxylation occurs through inverted binding in a 9α-hydroxylase. In order to discern the metabolic fate of more symmetrical molecules, we have investigated the metabolism of a range of steroidal analogues functionalised with ring-D lactones, but differing in their functional group stereochemistry at carbon-3. Remarkably, the 3α-functionalised steroidal lactones underwent a mechanistically unique two step intramolecular cyclisation resulting in the generation of a ring-D spiro-carbolactone. This rapid rearrangement initiated with hydroxylation at carbon 14 followed by transesterification, resulting in ring contraction with formation of a butyrolactone at carbon-14. Remarkably this rearrangement was found to be highly dependent on the stereochemistry at carbon-3, with the β-analogues only undergoing 9α-hydroxylation. The implications of these findings and their mechanistic bases are discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. BILATERAL MOLARIFORM SUPERNUMERARY TEETH IN THE ANTERIOR MAXILLA: A REPORT OF TWO CASES

    Directory of Open Access Journals (Sweden)

    Mehmet Cem ÖZDEN

    2017-01-01

    Full Text Available Supernumerary teeth are additional teeth besides the normal series and can be found in any region of the dental arch. Supernumerary teeth can be classified according to their form and locations. Early diagnosis and treatment of patients with supernumerary teeth may prevent or minimize complications. The treatment options depend on the type and position of the supernumerary tooth and its effect on the adjacent structures. Two male patients were referred to our clinic due to swelling in their maxillae and interrupted eruption of teeth. Upon radiological examination of the patients, impacted supernumerary teeth were found. Surgical removal of these teeth were perfomed and they were found to be molariform. We aim to present the two rare cases of molariform supernumerary teeth in this article.

  19. Múltiples dientes supernumerarios distomolares Multiple distomolars supernumerary teeth

    Directory of Open Access Journals (Sweden)

    F.J. Rodríguez Romero

    2009-12-01

    Full Text Available En una dentición normal, los dientes supernumerarios son aquellos descritos como adicionales a la serie. La etiología no esta clara. Se han descritos tanto en dentición primaria como en permanente, aunque son mas frecuentes en la dentición permanente. El objetivo de este informe es presentar un caso de una paciente con múltiples dientes supernumerarios distomolares. Cuartos molares bilaterales simétricos son sumamente raros.Supernumerary teeth are described as the teeth formed in excess of the number found in a normal dentition. The aetiology is not clear. Have been reported in both the primary and permanent dentition, although they are more prevalent in the permanent dentition. The purpose of this case report is to present a case of female patient with multiple distomolars supernumerary teeth. Bilateral symmetrical impacted fourth molars exceedingly uncommon.

  20. An observational study of the frequency of supernumerary teeth in a population of 2000 patients

    OpenAIRE

    Leco Berrocal, María Isabel; Martín Morales, José F.; Martínez González, José María

    2007-01-01

    An evaluation is made of the epidemiological characteristics of supernumerary teeth, with an analysis of the associated clinical-eruptive complications. A longitudinal observational study was made of 2000 patients, with the documentation of demographic data, the presence of supernumerary teeth, their location, mechanical accidents and the presence of associated pathology. The presence of supernumerary teeth was recorded in 1.05% of the study subjects (mean age 20.2 years), with a greater freq...

  1. Mesiodens with an unusual morphology and multiple impacted supernumerary teeth in a non-syndromic patient.

    Science.gov (United States)

    Srivatsan, Pavithra; Aravindha Babu, N

    2007-01-01

    Supernumerary teeth are a relatively frequent disorder of odontogenesis characterized by an excess number of teeth. Mesiodens is the most common type of supernumerary tooth found in the premaxilla between the two central incisors. They can be supplemental (resembling natural teeth), conical, tuberculate or molariform. We present the case of a 19 year-old girl who presented with a mesiodens of an unusual morphology and multiple impacted supernumerary teeth not associated with any syndrome.

  2. Mesiodens with an unusual morphology and multiple impacted supernumerary teeth in a non-syndromic patient

    Directory of Open Access Journals (Sweden)

    Srivatsan Pavithra

    2007-01-01

    Full Text Available Supernumerary teeth are a relatively frequent disorder of odontogenesis characterized by an excess number of teeth. Mesiodens is the most common type of supernumerary tooth found in the premaxilla between the two central incisors. They can be supplemental (resembling natural teeth, conical, tuberculate or molariform. We present the case of a 19 year-old girl who presented with a mesiodens of an unusual morphology and multiple impacted supernumerary teeth not associated with any syndrome.

  3. Prevalence and characteristics of supernumerary teeth in a non-syndromic South Indian pediatric population

    Directory of Open Access Journals (Sweden)

    Rajesh T Anegundi

    2014-01-01

    Full Text Available Background: Supernumerary teeth are one of the most widely reported and significant anomaly in patients affecting the primary and early mixed dentition. Aim: To describe the distribution and characteristics of the supernumerary teeth in South Indian population of paediatric patients. Design: In a 12 year retrospective study, a total of 63,569 patients up to the age of 14 years who visited our department between June 2003 and May 2013 were revised.790 cases of supernumerary teeth were found. Patients were evaluated for age, sex, site, status of dentition, number, position, orientation and type of supernumerary teeth. Statistical analysis was carried out using chi square test. Results: 790 subjects with supernumerary teeth (481 males and 309 females were detected, revealing male-female ratio of 1.55:1.The most common supernumerary teeth were mesiodens (82.28%, the most common site was the anterior maxilla (92.53%region. Majority of patients had a single erupted supernumerary oriented straight in the arch. Patients in mixed dentition stage reported with maximum number of supernumerary teeth. Conclusions: The prevalence of supernumerary teeth in non syndromicSouth Indian paediatric population is 1.24% with slight male predilection and conical mesiodens being the commonest.

  4. Prevalence and characteristics of supernumerary teeth in a non-syndromic South Indian pediatric population.

    Science.gov (United States)

    Anegundi, Rajesh T; Tegginmani, Veeresh S; Battepati, Prashant; Tavargeri, Anand; Patil, Shruthi; Trasad, Vijay; Jain, Garima

    2014-01-01

    Supernumerary teeth are one of the most widely reported and significant anomaly in patients affecting the primary and early mixed dentition. To describe the distribution and characteristics of the supernumerary teeth in South Indian population of paediatric patients. In a 12 year retrospective study, a total of 63,569 patients up to the age of 14 years who visited our department between June 2003 and May 2013 were revised.790 cases of supernumerary teeth were found. Patients were evaluated for age, sex, site, status of dentition, number, position, orientation and type of supernumerary teeth. Statistical analysis was carried out using chi square test. 790 subjects with supernumerary teeth (481 males and 309 females) were detected, revealing male-female ratio of 1.55:1.The most common supernumerary teeth were mesiodens (82.28%), the most common site was the anterior maxilla (92.53%)region. Majority of patients had a single erupted supernumerary oriented straight in the arch. Patients in mixed dentition stage reported with maximum number of supernumerary teeth. The prevalence of supernumerary teeth in non syndromic South Indian paediatric population is 1.24% with slight male predilection and conical mesiodens being the commonest.

  5. Genetics and presence of non-syndromic supernumerary teeth: A mystery case report and review of literature

    OpenAIRE

    Neha Khambete; Rahul Kumar

    2012-01-01

    Presence of supernumerary teeth is well-recognized clinical phenomenon. However, it is uncommon to find multiple supernumeraries in individuals with no other associated disease or syndrome. Presence of multiple supernumerary teeth is thought to have genetic component. We report a rare case where multiple supernumerary teeth were seen without presence of any other syndrome in 3 generations; father, son, and two grandsons. We also present a review of similar cases published in literature till d...

  6. Diagnosis and Surgical Management of Nonsyndromic Nine Supernumerary Teeth and Leong's Tubercle.

    Science.gov (United States)

    Cruz, Christiane V; Soares, Andrea L; Braga, David N; Costa, Marcelo C

    2016-01-01

    Nonsyndromic multiple supernumerary teeth (ST) and Leong's tubercle are a condition with a very low prevalence and a multidisciplinary approach is required to restore function and aesthetics. So, this case report aimed at presenting a rare case of nonsyndromic nine supernumerary teeth and Leong's tubercle in a pediatric patient, without any evident familial history, showing its diagnosis and surgical management.

  7. Radiographic Follow-Up during Orthodontic Treatment for Early Diagnosis of Sequential Supernumerary Teeth

    Science.gov (United States)

    Suga, Uhana Seifert Guimarães; Terada, Raquel Sano Suga

    2016-01-01

    Most supernumerary teeth are impacted and asymptomatic. Objective. The aim of this paper is to describe two cases of sequential development of supernumerary teeth in the mandibular premolar region, identified during orthodontic treatment. Reports. The first case describes the radiographic follow-up of a female patient that presented a supernumerary tooth at the age of 9 years and 10 months in the right mandibular premolar region, followed by a further supernumerary tooth in the left mandibular premolar region identified at the age of 11 years and 3 months. In the second case, the radiographic follow-up of a male patient demonstrated 3 supernumerary teeth in the premolar region at the age of 16 years. During orthognathic surgery planning at the age of 20 years and 5 months, a supplemental supernumerary tooth was found in the left mandibular region. Conclusion. Considering the late developing of supernumerary premolars, appropriate follow-up with panoramic radiographs of patients with previous experience of supernumerary teeth is essential for early diagnosis of supplemental premolars to prevent possible complications. PMID:27313911

  8. Prevalence of impacted and supernumerary teeth in the North Indian population.

    Science.gov (United States)

    Patil, Santosh; Maheshwari, Sneha

    2014-04-01

    Dental impaction is a very frequent problem. Supernumerary teeth, or hyperdontia, are the presence of additional teeth to the normal series in the either of the dentition. The presence of impacted and/or supernumerary teeth can cause various complications. The objective of the present study was to determine the prevalence of impacted and supernumerary teeth in the North Indian population. The panoramic radiographic records of 4750 patients attending the Department of Oral Medicine and Radiology, Jodhpur Dental College General Hospital between September 2008 to December 2012 were examined for this retrospective study. The ages of the patients ranged from 8 to 72 years, with a mean of 34.6 years. A total of 798 (16.8%) patients presented with 1126 impacted teeth. Impacted canines were the most prevalent (9.7%), followed by impacted premolars (4.3%). Supernumerary teeth (1.6%) and impacted molars (1.2%) were less prevalent. Among the 842 impacted teeth, the most frequently affected teeth were the canines (56.7%), followed by premolars (27.8%), and supernumerary teeth (9.3%), while the prevalence of impacted molars was quite lower (6.2%). The most frequently impacted teeth were maxillary canines and the mesiodens were the most common supernumerary tooth. The early diagnosis of supernumerary and impacted teeth is essential to prevent malocclusion and malalignment of permanent teeth demonstrating the importance of panoramic radiographs in their detection. Key words:Impacted, supernumerary, prevalence, canines, mesiodens.

  9. Groups, rings, modules

    CERN Document Server

    Auslander, Maurice

    2014-01-01

    This classic monograph is geared toward advanced undergraduates and graduate students. The treatment presupposes some familiarity with sets, groups, rings, and vector spaces. The four-part approach begins with examinations of sets and maps, monoids and groups, categories, and rings. The second part explores unique factorization domains, general module theory, semisimple rings and modules, and Artinian rings. Part three's topics include localization and tensor products, principal ideal domains, and applications of fundamental theorem. The fourth and final part covers algebraic field extensions

  10. Prevalence of supernumerary teeth in a nonsyndromic Syrian sample.

    Science.gov (United States)

    Burhan, Ahmad S; Nawaya, Fehmieh R; Arabi Katbi, Mohammad E; Al-Jawabra, Alaa S

    2015-12-01

    Supernumerary teeth (ST), also known as hyperdontia, is a condition in which more than the normal number of teeth are present in the series. The prevalence of ST varies between and within different populations. These teeth may cause various complications. The aim of the current study was to investigate the prevalence and characteristics of ST in Damascus inhabitants, Syria. A cross-sectional study was carried out using retrospectively collected digital panoramic radiographs of 2753 patients (1047 males and 1706 females) ranging in age from 12.2 to 20.5 years between January 2012 and December 2014. These radiographs were obtained from private dental offices spread across Damascus, Syria. For each patient with ST, the demographic variables, number, location, type, position, morphology of ST, and complications were recorded. ST were detected in 39 patients (1.4%), of whom 25 (64.1%) were males and 14 (35.9%) were females, with a male to female ratio of 1.8 : 1 (PMesiodens was the most prevalent ST (39.1%), followed by supernumerary premolars (28.3%), supernumerary laterals (26.1%), distomolars (4.3%), and paramolars (2.2%). This series includes cases with one and two ST. Of the 46 ST detected, 56.5% had a conical morphology, 89.1% were in a vertical position, and 19.6% were erupted. ST caused displacement of the adjacent teeth in 17 cases (37.0%) and the impaction of the permanent teeth in five cases (10.9%). The prevalence of ST in Damascus inhabitants was found to be 1.4%; the most frequent type was mesiodens. A conical morphology was found to be the most common form of ST. Displacement of permanent teeth is the most frequent complication. Further studies should be carried out on more representative samples of both the public and the private sector patients.

  11. Derivation of a true (t → 0+) quantum transition-state theory. I. Uniqueness and equivalence to ring-polymer molecular dynamics transition-state-theory.

    Science.gov (United States)

    Hele, Timothy J H; Althorpe, Stuart C

    2013-02-28

    Surprisingly, there exists a quantum flux-side time-correlation function which has a non-zero t → 0+ limit and thus yields a rigorous quantum generalization of classical transition-state theory (TST). In this Part I of two articles, we introduce the new time-correlation function and derive its t → 0+ limit. The new ingredient is a generalized Kubo transform which allows the flux and side dividing surfaces to be the same function of path-integral space. Choosing this function to be a single point gives a t → 0+ limit which is identical to an expression introduced on heuristic grounds by Wigner in 1932; however, this expression does not give positive-definite quantum statistics, causing it to fail while still in the shallow-tunnelling regime. Positive-definite quantum statistics is obtained only if the dividing surface is invariant to imaginary-time translation, in which case the t → 0+ limit is identical to ring-polymer molecular dynamics (RPMD) TST. The RPMD-TST rate is not a strict upper bound to the exact quantum rate, but is a good approximation to one if real-time coherence effects are small. Part II will show that the RPMD-TST rate is equal to the exact quantum rate in the absence of recrossing.

  12. Non-syndromic multiple supernumerary premolars: Clinicoradiographic report of five cases

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    Renu Tanwar

    2017-03-01

    Full Text Available Hyperdontia or supernumerary teeth in both arches without any syndromic manifestation are extremely rare. Supernumerary teeth are commonly associated with Gardner’s syndrome, cleft lip and palate, cleidocranial dysplasia and trichorhinopha-langeal syndrome. Five cases of non-syndromic multiple premolars of maxillary and mandibular arches in Indian patients are presented here. This case series reports three cases with multiple (9 in maximum, bilaterally impacted and erupted supernumerary teeth and two cases with supernumerary premolars in non-syndromic cases from Indian patients. Supernumerary teeth can be present in any region of the oral cavity. Although the occurrence of maxillary para-premolars is rare, radio-logical investigations play a major and decisive role in determining the management of such cases.

  13. The study of impacted and supernumerary teeth in young man by the full mouth roentgenograms

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Hung Kyu [Department of Dental Radiology, College of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    1977-11-15

    The author has observed 906 full mouth roentgenograms in Korean young man who had the impacted and supernumerary teeth. Impacted and supernumerary teeth were analysed upon several items, such as incidences and positions in the dental arch . The results were as follows; 1. The incidences of impacted teeth were 59.05%, and the ratio of upper jaw to lower one was 1:3. 2. The frequency of the supernumerary teeth were 5.52%, and the ratio of maxilla to mandible was 49:1. 3. No significant differences between right and left side in both jaws, but incidence rate of the supernumerary teeth was 74% in the maxillary central incisor area. 4. The positions of impacted and supernumerary teeth were vertical and inverted shapes in maxilla, whereas horizontal a nd mesio-angular forms in mandible.

  14. Cystic Endometrioma with Coexisting Fibroma Originating in a Supernumerary Ovary in the Rectovaginal Pouch

    Science.gov (United States)

    Sakaguchi, Asumi; Kodama, Hiroko; Ogura, Kanako; Miwa, Ayako; Sugimori, Yayoi; Matuoka, Shozo; Matsumoto, Toshiharu

    2017-01-01

    A supernumerary ovary is an exceedingly rare disorder, in which the structure containing ovarian tissue is located at some distance from the normally placed ovary. 16 cases of endometriosis or tumors originating in a supernumerary ovary have been published in the English literature, but no case of coexisting endometriosis and a tumor has been published. We present the case of a 40-year-old female with cystic endometrioma with coexisting fibroma originating in a supernumerary ovary in the rectovaginal pouch. The present case is the first to be reported with coexisting endometriosis and a tumor originating in a supernumerary ovary. Our experience with this case and the results of our previous studies of rectovaginal endometriosis indicated that the possibility of originating in a supernumerary ovary shall be examined in cases of cystic endometrioma in the rectovaginal pouch. PMID:28210515

  15. Múltiples dientes supernumerarios distomolares Multiple distomolars supernumerary teeth

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    F.J. Rodríguez Romero; S. Cerviño Ferradanes

    2009-01-01

    En una dentición normal, los dientes supernumerarios son aquellos descritos como adicionales a la serie. La etiología no esta clara. Se han descritos tanto en dentición primaria como en permanente, aunque son mas frecuentes en la dentición permanente. El objetivo de este informe es presentar un caso de una paciente con múltiples dientes supernumerarios distomolares. Cuartos molares bilaterales simétricos son sumamente raros.Supernumerary teeth are described as the teeth formed in excess of th...

  16. Genetics and presence of non-syndromic supernumerary teeth: A mystery case report and review of literature.

    Science.gov (United States)

    Khambete, Neha; Kumar, Rahul

    2012-10-01

    Presence of supernumerary teeth is well-recognized clinical phenomenon. However, it is uncommon to find multiple supernumeraries in individuals with no other associated disease or syndrome. Presence of multiple supernumerary teeth is thought to have genetic component. We report a rare case where multiple supernumerary teeth were seen without presence of any other syndrome in 3 generations; father, son, and two grandsons. We also present a review of similar cases published in literature till date. The role of genetics in development of supernumerary teeth is highlighted.

  17. Genetics and presence of non-syndromic supernumerary teeth: A mystery case report and review of literature

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    Neha Khambete

    2012-01-01

    Full Text Available Presence of supernumerary teeth is well-recognized clinical phenomenon. However, it is uncommon to find multiple supernumeraries in individuals with no other associated disease or syndrome. Presence of multiple supernumerary teeth is thought to have genetic component. We report a rare case where multiple supernumerary teeth were seen without presence of any other syndrome in 3 generations; father, son, and two grandsons. We also present a review of similar cases published in literature till date. The role of genetics in development of supernumerary teeth is highlighted.

  18. Three Supernumerary Marker Chromosomes in a Patient with Developmental Delay, Mental Retardation, and Dysmorphic Features

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    Jie Hu

    2011-01-01

    Full Text Available We characterized three supernumerary marker chromosomes (SMCs simultaneously present in a 2-year- and 10-month-old male patient with mental retardation and dysmorphic features. Peripheral blood chromosome analysis revealed two to three SMCs in 25/26 cells analyzed. The remaining one cell had one SMC. Microarray comparative genomic hybridization (aCGH showed mosaicism for gains of 5q35.3, 15q11.2q13.3, and 18p11.21q11.1 regions. All three gains contain multiple OMIM genes. FISH studies indicated that one of the SMCs is a dicentric ring 15 with two copies of the 15q11.2q13.3 region including SNRPN/UBE3A and two copies of the 5q35.3 region. One of the der(18s contains the 18 centromere and 18p11.2 regions, while the other der(18 has a signal for the 18 centromere only. The phenotype of the patient is compared with that of patients with tetrasomy 15q11.2q13.3, trisomy 5q35.3, and trisomy 18p11.2. Our study demonstrates that aCGH and FISH analyses are powerful tools, which complement the conventional cytogenetic analysis for the identification of SMCs.

  19. Multiple supernumerary teeth and odontoma in the maxilla: A case report

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    P B Sood

    2010-01-01

    Full Text Available Most supernumerary impacted teeth are located in the anterior maxillary region. They are classified according to their form and location. Their presence may give rise to a variety of clinical problems. The detection of supernumerary teeth is best achieved by thorough clinical and radiographic examination. Their management should form part of a comprehensive treatment plan. This article presents an overview of the diagnostic problems associated with multiple supernumerary impacted teeth and includes a discussion of the classification, diagnosis, and management of this difficult clinical entity.

  20. Multiple supernumerary teeth associated with an impacted maxillary central incisor: Surgical and orthodontic management

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    Ramakrishna Yeluri

    2012-01-01

    Full Text Available Various anomalies in the size, shape, number, structure and eruption of the teeth are often observed clinical conditions. Supernumerary teeth can be found in almost any region of the dental arch, and most of the times they are asymptomatic, and are routinely found during radiographic evaluation. The most common cause of impacted maxillary incisors is the presence of the supernumerary teeth. This paper describes a case of multiple supernumerary teeth associated with an impacted permanent maxillary central incisor in an 11-year old child along with its surgical and orthodontic management.

  1. Endoscopic Removal of a Supernumerary Premolar in the Mandible during a Dental Implant Placement

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    Víctor Beltrán

    2014-01-01

    Full Text Available The surgical removal of supernumerary teeth is necessary in some cases, especially before the commencement of any orthodontic or implant treatment procedure. In the mandibular supernumerary premolar, a more conservative approach is required because of the presence of complications associated with conventional surgery due to the close proximity of the said premolar to the alveolar inferior and mental nerves, and the need for bone conservation for implant placement. The endoscopic surgical approach has been used for the removal of the maxillary supernumerary tooth, impacted third molar, and implants. In this case report, we present an endoscopically assisted surgical technique for the removal of an unerupted supernumerary premolar in the mandible associated with a dental implant placement procedure.

  2. Agenesis of premolar associated with submerged primary molar and a supernumerary premolar: An unusual case report

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    S. V. S. G. Nirmala

    2012-01-01

    Full Text Available The combination of submerged primary molar, agenesis of permanent successor with a supernumerary in the same place is very rare. The purpose of this article is to report a case of submerged mandibular left second primary molar with supernumerary tooth in the same region along with agenesis of second premolar in an 11-year-old girl, its possible etiological factors, and a brief discussion on treatment options.

  3. Diagnosis and management of supernumerary (mesiodens): a review of the literature.

    Science.gov (United States)

    Meighani, G; Pakdaman, A

    2010-01-01

    Supernumerary tooth is one of the developmental problems in children. Mesiodens is a supernumerary tooth present in the midline between the two central incisors. It usually results in oral problems such as malocclusion, food impaction, poor aesthetics, and cyst formation. The prevalence of mesiodens varies between 0.09% and 2.05% in different studies. This paper reviews current literature on etiology, prevalence, diagnosis, and management of this problem. Accordingly, early diagnosis and treatment is suggested to prevent orthodontic and pathologic complications.

  4. Coexistent partial anodontia and supernumerary tooth in the mandibular arch: A rare case

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    Das G

    2006-05-01

    Full Text Available Coexistent partial anodontia and supernumerary tooth in the lower jaw is a very uncommon condition. Very few cases have been reported in the literature of this condition, etiology of which is still obscure. Presented here is a rare case of simultaneous presence of single supernumerary tooth together with missing permanent central incisor teeth in the lower jaw without any associated systemic condition or syndrome.

  5. Histological Evaluation and Management of Rare Case of Supernumerary “Ghost” Teeth

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    Dino Re

    2017-01-01

    Full Text Available Supernumerary teeth are teeth that exceed the normal dental formula. Their prevalence in the permanent dentition is 1–14% and they occur more frequently in maxilla with a sex ratio of 2 : 1 in favor of males. They are often associated with syndromes but there are examples of nonsyndromic multiple supernumerary teeth reported in the literature. CBCT is usually the best exam for radiographic diagnosis and treatment planning, because it provides 3D information about location and morphology of supernumerary teeth. This paper reports a rare case of four supernumerary teeth in a nonsyndromic 9-year-old boy. The peculiarity of this case is that two more exceeding teeth were found during surgical procedure. After extraction, all the teeth underwent a histological undecalcified processing for light microscopical examination. The two “ghost” supernumerary teeth seemed to be primordial dental germs, possibly resulting from an altered odontogenic process. After supernumerary teeth extraction, X-rays and exfoliation monitoring are recommended, since permanent retained teeth often erupt naturally or, at least, improve their condition. Radiographic follow-up is also useful in order to assess the formation of further teeth due to the hyperactivity of the dental lamina.

  6. Prevalence rate of supernumerary teeth among non-syndromic South Indian population: An analysis

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    M Nazargi Mahabob

    2012-01-01

    Full Text Available Aim: Supernumerary teeth are considered as one of the most significant dental anomalies during the primary and early mixed dentition stage. The main objective of the study was to determine the prevalence rate of supernumerary teeth in the patients who reported to the Department of Oral Medicine and Radiology and to study the associated clinical complications. Materials and Methods: A longitudinal observational study was conducted of 2216 patients for a period of 4 months with the documentation of demographic data, the presence of supernumerary teeth, their location, and associated complications such as mechanical trauma, dental caries, and associated pathology. Results: The study recorded 27 supernumerary teeth from the examined 2216 patients. This yields a prevalence of 1.2%, with greater frequency in males which was 1.49% and in females the frequency was 0.85%. The greatest proportion of supernumerary teeth was found in the maxillary anterior region (77.8%. Out of this, 85.7% were classified as mesiodens based on their location. The displacement of adjacent teeth was the most common finding, followed by dental caries. Conclusion: The prevalence of supernumerary teeth in this study was 1.2% which is in agreement with that reported in similar studies and the maxillary mesiodens was the most common location. Displacement of adjacent teeth was the most common finding.

  7. Prevalence rate of supernumerary teeth among non-syndromic South Indian population: An analysis.

    Science.gov (United States)

    Mahabob, M Nazargi; Anbuselvan, G J; Kumar, B Senthil; Raja, S; Kothari, Sucitha

    2012-08-01

    Supernumerary teeth are considered as one of the most significant dental anomalies during the primary and early mixed dentition stage. The main objective of the study was to determine the prevalence rate of supernumerary teeth in the patients who reported to the Department of Oral Medicine and Radiology and to study the associated clinical complications. A longitudinal observational study was conducted of 2216 patients for a period of 4 months with the documentation of demographic data, the presence of supernumerary teeth, their location, and associated complications such as mechanical trauma, dental caries, and associated pathology. The study recorded 27 supernumerary teeth from the examined 2216 patients. This yields a prevalence of 1.2%, with greater frequency in males which was 1.49% and in females the frequency was 0.85%. The greatest proportion of supernumerary teeth was found in the maxillary anterior region (77.8%). Out of this, 85.7% were classified as mesiodens based on their location. The displacement of adjacent teeth was the most common finding, followed by dental caries. The prevalence of supernumerary teeth in this study was 1.2% which is in agreement with that reported in similar studies and the maxillary mesiodens was the most common location. Displacement of adjacent teeth was the most common finding.

  8. The post-natal fate of supernumerary ribs in rat teratogenicity studies.

    Science.gov (United States)

    Wickramaratne, G A

    1988-04-01

    A common occurrence in rat teratology studies, supernumerary ribs, have been considered to be indicative of teratogenicity by some authors but not to be so indicative by others. As a teratogenic event is, by definition a permanent change, a study to follow the fate of supernumerary ribs in the development of adulthood of the rat was undertaken. An established teratogen in the rat, aspirin, was used to increase the frequency of supernumerary ribs. Even though aspirin treatment of the dams doubled the initial frequency of supernumerary ribs the results show that over the first 60 days post-partum their frequency in both control and treated groups decline to essentially zero. This decline in frequency of supernumerary ribs is complemented by an increase in the proportion of foetuses with a fully developed transverse process on the first lumbar vertebra. The proposal that supernumerary ribs in the rat are a result of developmental delays in a labile region of the axial skeleton and not a manifestation of a teratogenic event is presented.

  9. INVESTIGATION OF IMPACTED SUPERNUMERARY TEETH: A CONE BEAM COMPUTED TOMOGRAPH (CBCT STUDY

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    Gökhan GÜRLER

    2017-10-01

    Full Text Available Purpose: The purpose of this study was to investigate the impacted supernumerary teeth which were initially detected on panoramic radiographs by using cone beam computed tomography (CBCT. Materials and Methods: In this retrospective study, supernumerary teeth diagnosed on panoramic radiographs taken from patients who had admitted for routine dental treatment were evaluated using CBCT. Patients’ age, gender, systemic conditions as well as number of supernumerary teeth, unilateral-bilateral presence, anatomical localization (maxilla, mandible, anterior-premolar-molar, mesiodens-lateral-canine, parapremolar-paramolar-distomolar shape (rudimentary, supplemental, tuberculate, odontoma, position (palatal-lingual-buccal-labial-central, shortest distance between the tooth and adjacent cortical plate, complications and treatment were assessed. Results: A total of 47 impacted supernumerary teeth in 34 patients were investigated in this study. Of these, 33 (70.2% were unilateral and 14 (29.8% were bilateral. Only 1 supernumerary tooth was found in 27 patients (79.4% whereas 7 patients (20.6% had 2 or more supernumerary teeth. Most of the teeth located in the anterior region (74.4% of the jaws and maxilla (74.4%. Twenty teeth (42.5% were mesiodens, 11 (23.4% were lateral or canine, 14 (29.7% were parapremolar and 2(4.4% were distomolar. Twenty-seven teeth (57.4% were rudimentary, 15 (31.9% were supplemental and 5 (10.7% were odontoma in shape. The shortest distance between the supernumerary tooth and adjacent cortical plate varied between 0 to 2.5 mm with a mean of 0.66 mm. The most common clinical complaint was the non-eruption of permanent teeth (42.5%. All supernumerary teeth were removed under local anesthesia. Orthodontic traction was performed for those impacted permanent teeth if necessary. Conclusion: Impacted supernumerary teeth are usually in close proximity to cortical bone. Although this may facilitate surgical access, there is a risk of

  10. Somatic Mosaicism in Cases with Small Supernumerary Marker Chromosomes

    Science.gov (United States)

    Liehr, Thomas; Karamysheva, Tatyana; Merkas, Martina; Brecevic, Lukrecija; Hamid, Ahmed B.; Ewers, Elisabeth; Mrasek, Kristin; Kosyakova, Nadezda; Weise, Anja

    2010-01-01

    Somatic mosaicism is something that is observed in everyday lives of cytogeneticists. Chromosome instability is one of the leading causes of large-scale genome variation analyzable since the correct human chromosome number was established in 1956. Somatic mosaicism is also a well-known fact to be present in cases with small supernumerary marker chromosomes (sSMC), i.e. karyotypes of 47,+mar/46. In this study, the data available in the literature were collected concerning the frequency mosaicism in different subgroups of patients with sSMC. Of 3124 cases with sSMC 1626 (52%) present with somatic mosaicism. Some groups like patients with Emanuel-, cat-eye- or i(18p)- syndrome only tend rarely to develop mosaicism, while in Pallister-Killian syndrome every patient is mosaic. In general, acrocentric and non-acrocentric derived sSMCs are differently susceptible to mosaicism; non-acrocentric derived ones are hereby the less stable ones. Even though, in the overwhelming majority of the cases, somatic mosaicism does not have any detectable clinical effects, there are rare cases with altered clinical outcomes due to mosaicism. This is extremely important for prenatal genetic counseling. Overall, as mosaicism is something to be considered in at least every second sSMC case, array-CGH studies cannot be offered as a screening test to reliably detect this kind of chromosomal aberration, as low level mosaic cases and cryptic mosaics are missed by that. PMID:21358988

  11. Multiple forms of atypical rearrangements generating supernumerary derivative chromosome 15

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    Sigman Marian

    2008-01-01

    Full Text Available Abstract Background Maternally-derived duplications that include the imprinted region on the proximal long arm of chromosome 15 underlie a complex neurobehavioral disorder characterized by cognitive impairment, seizures and a substantial risk for autism spectrum disorders1. The duplications most often take the form of a supernumerary pseudodicentric derivative chromosome 15 [der(15] that has been called inverted duplication 15 or isodicentric 15 [idic(15], although interstitial rearrangements also occur. Similar to the deletions found in most cases of Angelman and Prader Willi syndrome, the duplications appear to be mediated by unequal homologous recombination involving low copy repeats (LCR that are found clustered in the region. Five recurrent breakpoints have been described in most cases of segmental aneuploidy of chromosome 15q11-q13 and previous studies have shown that most idic(15 chromosomes arise through BP3:BP3 or BP4:BP5 recombination events. Results Here we describe four duplication chromosomes that show evidence of atypical recombination events that involve regions outside the common breakpoints. Additionally, in one patient with a mosaic complex der(15, we examined homologous pairing of chromosome 15q11-q13 alleles by FISH in a region of frontal cortex, which identified mosaicism in this tissue and also demonstrated pairing of the signals from the der(15 and the normal homologues. Conclusion Involvement of atypical BP in the generation of idic(15 chromosomes can lead to considerable structural heterogeneity.

  12. Mesiodens--diagnosis and management of a common supernumerary tooth.

    Science.gov (United States)

    Russell, Kathleen A; Folwarczna, Magdalena A

    2003-06-01

    Mesiodentes are the most common supernumerary teeth, occurring in 0.15% to 1.9% of the population. Given this high frequency, the general dentist should be knowledgeable about the signs and symptoms of mesiodentes and appropriate treatment. The cause of mesiodentes is not fully understood, although proliferation of the dental lamina and genetic factors have been implicated. Mesiodentes can cause delayed or ectopic eruption of the permanent incisors, which can further alter occlusion and appearance. It is therefore important for the clinician to diagnose a mesiodens early in development to allow for optimal yet minimal treatment. Treatment options may include surgical extraction of the mesiodens. If the permanent teeth do not erupt in a reasonable period after the extraction, surgical exposure and orthodontic treatment may be required to ensure eruption and proper alignment of the teeth. In some instances, fixed orthodontic therapy is also required to create sufficient arch space before eruption and alignment of the incisor(s). Early diagnosis allows the most appropriate treatment, often reducing the extent of surgery, orthodontic treatment and possible complications. This paper outlines the causes and modes of presentation of mesiodentes, and presents guidelines for diagnosis and management of nonsyndromic mesiodentes.

  13. Mirror imaging of impacted and supernumerary teeth in dizygotic twins: A case report.

    Science.gov (United States)

    Cassetta, Michele; Altieri, Federica; Giordano, Alessandra

    2015-02-01

    Mesiodens is the most common type of supernumerary tooth found in the premaxilla. It might be discovered by the clinical examination by chance on a radiograph or as the cause of an unerupted maxillary central incisor. The genetic transmission of supernumerary and impacted teeth is poorly understood. Mirror imaging in twins has been reported frequently in relation to several unilateral dental anomalies including mesiodens. This phenomenon is the appearance of an asymmetrical feature or anomaly occurring on the right side of one twin but on the left side of the other twin. The event of mesiodens mirror imaging in monozygotic twins has been described in literature. This is the first reported case of mesiodens mirror images in dizygotic twins. The de-scribed mesiodens caused the eruption failure of maxillary permanent incisors. The super-numerary teeth were removed to facilitate the spontaneous eruption of the impacted perma-nent maxillary incisors. Studies related to supernumerary teeth can be useful to clinicians in the early diagnosis of this anomaly. Clinical and radiographic examinations provide a correct therapeutic approach. Key words:Supernumerary teeth, twins, dental development.

  14. Vascular ring

    Science.gov (United States)

    ... subclavian and left ligamentum ateriosus; Congenital heart defect - vascular ring; Birth defect heart - vascular ring ... Vascular ring is rare. It accounts for less than 1% of all congenital heart problems. The condition ...

  15. Multiple Supernumerary Teeth in a Non-Syndromic Patient: A Case Report

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    Majid Eshgh Pour

    2013-01-01

    Full Text Available Introduction: Multiple supernumerary teeth are a rare phenomenon. It occurs more often in patients with syndromes such as Gardner's syndrome, cleidocranial dysplasia and so on. This phenomenon in absence of such syndromes is rare. The purpose of this report was to introduce a case of non-syndromic multiple supernumerary impacted teeth.Case Report: A 29-year-old woman with no skeletal, metabolic, systemic and mental disorder was referred to oral and maxillofacial department of Mashhad dental school. In clinical evaluation, seven Permanent teeth were missing. In radiographic evaluation, there were a total of 15 impacted teeth which 7 of them were supernumerary.Conclusion: Missing or Excess of one or more teeth usually leads to occlusal and functional problems. In these cases, a complete clinical and radiographic examination accompanieal by a precise history should be performed to plan a suitable surgical-orthodontic-prosthetic treatment.

  16. Sequential supernumerary teeth development in a non-syndromic patient; report of a rare case.

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    Mohammad Jafarian

    2013-12-01

    Full Text Available Isolated impacted supernumerary teeth are quite rare, but they can be seen associated with several syndromes such as cleidocranial dysostosis or Gardner's syndrome. This article aims to discuss a case of sequential formation of supernumerary teeth with no other associated disease or syndrome. A 17-year-old Iranian male with 8 impacted supernumerary teeth was referred to the department of pediatric dental clinic at Shahid Beheshti Medical University in Tehran with a history of several impacted unerupted teeth. Repeated and periodical clinical and radiographic examinations revealed newly formed teeth buds in unusual dental ages. All extra teeth were associated with generalized enamel hypoplasia to some degree on their relative permanent adjacent teeth. The patient did not have any record of a systemic disease or any syndromic condition to relate his dental problem to. This rare condition involved repeated and continued formation of extra teeth out of the normal numbers and dental age evident in serial radiographs.

  17. Use of a Piezosurgery Technique to Remove a Deeply Impacted Supernumerary Tooth in the Anterior Maxilla

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    Shintaro Sukegawa

    2015-01-01

    Full Text Available Deeply impacted supernumerary teeth in the anterior maxillary cannot be generally removed by the conventional labial or palatal surgical approach because of the risk of damaging the surrounding soft tissues and the possibility of injuring the roots of adjacent permanent teeth. In piezosurgery, bony tissues are selectively cut, thereby avoiding the soft tissue damage caused by rotary cutting instruments. We report the case of a 15-year-old Japanese boy from whom a deeply impacted supernumerary tooth in the anterior maxillary was safely removed through the floor of the nasal cavity. The surgical extraction was performed without damaging the nasal mucosa or adjacent structures such as the roots of the adjacent permanent teeth. Considering that piezosurgery limits the extent of surgical invasion, this technique can be practiced as a minimally invasive and safe surgical procedure for treating suitably selected cases with a deeply impacted supernumerary tooth.

  18. Management of Delayed Eruption of Permanent Maxillary Incisor associated with the Presence of Supernumerary Teeth: A Case Report

    Science.gov (United States)

    Nagpal, Rajni; Singh, Mousumi; Chaudhary, Seema

    2011-01-01

    A supernumerary tooth is one that is additional to the normal series and can be found in almost any region of the dental arch. Clinically, supernumerary teeth are able to cause different local disorders. It is important for the dentist to be aware of the clinical complications of supernumerary teeth, the most common being the delayed eruption of permanent teeth. Early diagnosis and management of supernumerary teeth is important to prevent the need for more complex surgical and orthodontic treatment. This case report highlights the problem of delayed eruption of permanent maxillary left central incisor in a 9-year-old boy due to two supernumerary teeth, one tuberculate type and other impacted inverted mesiodens. PMID:27678238

  19. The dynamics of supernumerary tooth development are differentially regulated by Sprouty genes.

    Science.gov (United States)

    Lagronova-Churava, Svatava; Spoutil, Frantisek; Vojtechova, Simona; Lesot, Herve; Peterka, Miroslav; Klein, Ophir D; Peterkova, Renata

    2013-07-01

    In mice, a toothless diastema separates the single incisor from the three molars in each dental quadrant. In the prospective diastema of the embryo, small rudimentary buds are found that are presumed to be rudiments of suppressed teeth. A supernumerary tooth occurs in the diastema of adult mice carrying mutations in either Spry2 or Spry4. In the case of Spry2 mutants, the origin of the supernumerary tooth involves the revitalization of a rudimentary tooth bud (called R2), whereas its origin in the Spry4 mutants is not known. In addition to R2, another rudimentary primordium (called MS) arises more anteriorly in the prospective diastema. We investigated the participation of both rudiments (MS and R2) in supernumerary tooth development in Spry2 and Spry4 mutants by comparing morphogenesis, proliferation, apoptosis, size and Shh expression in the dental epithelium of MS and R2 rudiments. Increased proliferation and decreased apoptosis were found in MS and R2 at embryonic day (ED) 12.5 and 13.5 in Spry2(-/-) embryos. Apoptosis was also decreased in both rudiments in Spry4(-/-) embryos, but the proliferation was lower (similar to WT mice), and supernumerary tooth development was accelerated, exhibiting a cap stage by ED13.5. Compared to Spry2(-/-) mice, a high number of Spry4(-/-) supernumerary tooth primordia degenerated after ED13.5, resulting in a low percentage of supernumerary teeth in adults. We propose that Sprouty genes were implicated during evolution in reduction of the cheek teeth in Muridae, and their deletion can reveal ancestral stages of murine dental evolution. Copyright © 2013 Wiley Periodicals, Inc.

  20. An epidemiological study on supernumerary teeth: a survey on 5,000 people.

    Science.gov (United States)

    Kumar, Dara Kalyan; Gopal, K Saraswathy

    2013-07-01

    The formation of dental tissues is a highly delicate and complex phenomenon. Any alteration in this process leads to various dental anomalies which affect the tooth number, size, shape and structure. Supernumerary teeth are one such anomaly which affects the tooth number. Supernumerary teeth can give rise to various complications and pathologies or they may have a familial / syndromic association. They may occur along with other dental anomalies. Thus, such teeth have a definite clinical significance. The aim of the following study was to know the prevalence of the supernumerary teeth and the distribution of the cases according to the age, sex, jaw, region, eruption status, and the position. A total of 5000 patients were examined for a period of 1 year's duration and they were divided into different groups. Group I consisted of individuals who were aged between 5-20 years, Group II consisted of individuals who were aged between 21-40 years, and Group III consisted of individuals who were aged 41 years and above. The dental examination was conducted by using a mouth mirror and a probe, to determine the presence of supernumerary teeth. All the cases with supernumerary teeth were further observed and the details were recorded in a prepared porforma. These cases were also subjected to general physical examinations (to rule out any syndromes) and radiographic examinations. Photographs were also made. Although supernumerary teeth is an unusual anomaly, it is not as rare as was previously reported. The identification of this anomaly could provide a hint towards the possibility of complications, pathologies, other dental anomalies, syndromes and a familial association.

  1. Endodontic management of a supernumerary tooth fused to the maxillary permanent lateral Incisor

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    Avinash A Patil

    2014-01-01

    Full Text Available The aim of this case report is to present the endodontic management of a supernumerary tooth fused to the maxillary left lateral incisor. Such anomalies pose a challenge even to the most experienced clinician in treating these teeth. This report described a case of 21-year-old male patient with a classic case of complete fusion of maxillary left lateral incisor and a supernumerary tooth. A modified access preparation was made and two separate root canal orifices were identified. Both root canal systems were prepared separately and obturated efficiently until accepted lengths. This reported case highlights the importance of clinical and radiographic correlation in arriving to a definitive diagnosis.

  2. Unusual Case of a Talon Cusp on a Supernumerary Tooth in Association with a Mesiodens

    Directory of Open Access Journals (Sweden)

    Prashant Babaji

    2010-06-01

    Full Text Available Talon cusp is an accessory cusp similar to a projection, extending from the cingulum or cemento-enamel junction to the incisal edge. It occurs on labial or palatal surfaces of primary or permanent anterior teeth in both arches. This accessory cusp can occur as an isolated entity or in association with other dental anomalies. Occurrence of a talon cusp on supernumerary teeth is rare and uncommon. This paper reports an unusual case of a talon cusp on a supernumerary tooth in association with mesiodens.

  3. Hypohyperdontia: Agenesis of three third molars and mandibular centrals associated with midline supernumerary tooth in mandible

    Directory of Open Access Journals (Sweden)

    Sivakumar Nuvvula

    2010-01-01

    Full Text Available Agenesis of teeth in a patient who also presents with a supernumerary tooth is one of the rare numerical anomalies in human dentition. Agenesis of third molars was shown to be associated with other missing permanent teeth. A review of literature on hypodontia including third molar agenesis, hyperdontia and a concomitant presence of these two conditions which is termed as hypohyperdontia is presented along with a case showing agenesis of three third molars, both mandibular central incisors and a midline supernumerary tooth.

  4. Dentigerous cyst associated with ectopic canine and a supernumerary tooth: a rare occurrence.

    Science.gov (United States)

    Ramakrishna, Ashwini; Lambade, Pravin

    2013-07-01

    Amongst the cysts of the jaw dentigerous cyst (DC) is one of the most prevalent types of odontogenic cysts, which is associated with the crown of an unerupted or developing tooth. DC is more commonly seen with mandibular third molar and maxillary canine and rarely other teeth are involved. These cysts seldom associate with supernumerary teeth. The purpose of this article is to describe a case of large dentigerous cyst associated with supernumerary teeth and an ectopic canine, which is a rare presentation along with its management.

  5. Diagnosis and Management of Supernumerary (Mesiodens: A Review of the Literature

    Directory of Open Access Journals (Sweden)

    G. Meighani

    2010-03-01

    Full Text Available Supernumerary tooth is one of the developmental problems in children. Mesiodens is a supernumerary tooth present in the midline between the two central incisors. It usually results in oral problems such as malocclusion, food impaction, poor aesthetics, and cyst formation. The prevalence of mesiodens varies between 0.09% and 2.05% in different studies.This paper reviews current literature on etiology, prevalence, diagnosis, and management of this problem. Accordingly, early diagnosis and treatment is suggested to preventorthodontic and pathologic complications.

  6. Unusual case of a talon cusp on a supernumerary tooth in association with a mesiodens.

    Science.gov (United States)

    Babaji, Prashant; Sanadi, Firoza; Melkundi, Mahesh

    2010-01-01

    Talon cusp is an accessory cusp similar to a projection, extending from the cingulum or cemento-enamel junction to the incisal edge. It occurs on labial or palatal surfaces of primary or permanent anterior teeth in both arches. This accessory cusp can occur as an isolated entity or in association with other dental anomalies. Occurrence of a talon cusp on supernu-merary teeth is rare and uncommon. This paper reports an unusual case of a talon cusp on a supernumerary tooth in association with mesiodens.

  7. Ring blowers. Ring blower

    Energy Technology Data Exchange (ETDEWEB)

    Nakahara, Y.; Okamura, T.; Takahashi, M. (Fuji Electric Co. Ltd., Tokyo (Japan))

    1991-06-10

    Features, structures and several products of ring blowers were outlined. The ring blower is featured by its medium characteristics because it is higher in air pressure than a turboblower and larger in airflow than a vane blower, and it is applicable flexibly to not only air blasting but various industrial fields such as suction transfer. As several products corresponding to various fields, the followings were outlined: the low noise type with optimum shapes of inlet, outlet and casing cover for reducing noises by 10 dB or more, the heat resistant, water-tight and explosion-proof types suitable for severe environmental conditions, the multi-voltage type for every country served at different voltages, the high air pressure type with two pressure rise stages, and the large airflow type with a wide impeller. In addition, as special use products, the glass fiber reinforced unsatulated polyester ring blower for respiration apparatus, and the variable speed blushless DC motor-driven one for medical beds were outlined. 2 refs., 9 figs., 1 tab.

  8. Centromere activity in dicentric small supernumerary marker chromosomes.

    Science.gov (United States)

    Ewers, Elisabeth; Yoda, Kinya; Hamid, Ahmed B; Weise, Anja; Manvelyan, Marina; Liehr, Thomas

    2010-07-01

    Twenty-five dicentric small supernumerary marker chromosomes (sSMC) derived from #13/21, #14, #15, #18, and #22 were studied by immunohistochemistry for their centromeric activity. Centromere protein (CENP)-B was applied as marker for all centromeres and CENP-C to label the active ones. Three different 'predominant' activation patterns could be observed, i.e., centric fusion or either only one or all two centromeres were active. In one inherited case, the same activation pattern was found in mother and son. In acrocentric-derived sSMC, all three activation patterns could be present. In contrary, in chromosome 18-derived sSMC, only the fusion type was observed. In concordance with previous studies a certain centromeric plasticity was observed in up to 13% of the cells of an individual case. Surprisingly, the obtained data suggests a possible influence of the sSMC carrier's gender on the implementation of the predominant activation pattern; especially, only one active centromere was found more frequently in female than in male carriers. Also, it might be suggested that dicentric sSMC with one active centromere could be less stable than such with two active ones-centromeric plasticity might have an influence here, as well. Also, centromere activity in acrocentric-derived dicentrics could be influenced by heteromorphisms of the corresponding short arms. Finally, evidence is provided that the closer the centromeres of a dicentric are and if they are not fused, the more likely it was that both of them became active. In concordance and refinement with previous studies, a distance of 1.4 Mb up to about 13 Mb the two active centromere state was favored, while centromeric distance of over approximately 15 Mb lead to inactivation of one centromere. Overall, here, the first and largest ever undertaken study in dicentric sSMC is presented, providing evidence that the centromeric activation pattern is, and parental origin may be of interest for their biology. Influence of

  9. Clinical management of a fused upper premolar with supernumerary tooth: a case report

    Directory of Open Access Journals (Sweden)

    Kyu-Min Cho

    2014-11-01

    Full Text Available n dentistry, the term 'fusion' is used to describe a developmental disorder of dental hard tissues. In the permanent dentition, fusion of a normal tooth and a supernumerary tooth usually involves the incisors or canines. However, a few cases of fusion involving premolars have also been reported to date. We present a rare case in which fusion of the maxillary left second premolar and a supernumerary tooth in a 13-year-old girl was diagnosed using cone beam computed tomography (CBCT, Alphard-3030, Asahi Roentgen Ind. Co., Ltd.. The tooth was bicuspidized after routine nonsurgical root canal treatment, and the separated teeth underwent appropriate restoration procedures. The second premolar and supernumerary tooth remained asymptomatic without any signs of inflammation after a follow-up period of 9 years. Identification of anatomical anomalies is important for treatment in cases involving fusion with supernumerary tooth, and therefore the microscopic examinations and CBCT are essential for the diagnosis. Fused teeth can be effectively managed by the comprehensive treatment which includes both endodontic and periodontal procedures.

  10. Lateral incisor agenesis, canine impaction and characteristics of supernumerary teeth in a South European male population

    NARCIS (Netherlands)

    Delli, Konstantina; Livas, Christos; Bornstein, Michael M

    2013-01-01

    OBJECTIVE: To assess the prevalence of lateral incisor agenesis impacted canines and supernumerary teeth in a young adult male population. MATERIALS AND METHODS: The panoramic radiographs of 1745 military students (mean age: 18.6 ± 0.52 years) who attended the Center of Aviation Medicine of the Arme

  11. Multiple crown size variables of the upper incisors in patients with supernumerary teeth compared with controls

    NARCIS (Netherlands)

    Khalaf, K.; Smith, R. N.; Elcock, C.; Brook, A. H.

    2009-01-01

    Aims: As part of ongoing studies of the aetiology of dental anomalies the aims of this study were to identify multiple components of tooth size of the upper permanent incisors in 34 patients with supernumerary teeth and to compare them with those in a control group to determine whether the presence

  12. Lateral incisor agenesis, canine impaction and characteristics of supernumerary teeth in a South European male population

    NARCIS (Netherlands)

    Delli, Konstantina; Livas, Christos; Bornstein, Michael M

    2013-01-01

    OBJECTIVE: To assess the prevalence of lateral incisor agenesis impacted canines and supernumerary teeth in a young adult male population. MATERIALS AND METHODS: The panoramic radiographs of 1745 military students (mean age: 18.6 ± 0.52 years) who attended the Center of Aviation Medicine of the Arme

  13. Multidisciplinary management of impacted central incisors due to supernumerary teeth and an associated dentigerous cyst

    Directory of Open Access Journals (Sweden)

    Ritesh R Kalaskar

    2011-01-01

    Full Text Available Supernumerary teeth are the most common developmental dental anomaly resulting from hyperactivity of dental lamina, dichotomy, environmental factor, or polygenetic process of atavism. Supernumerary teeth present classical oral complication such as impaction of adjacent teeth, crowding, diastema formation, rotation, displacement of teeth, and occlusal interference. A dentigerous cyst associated with anterior supernumerary teeth (mesiodens is rare and accounts for 5% of all dentigerous cysts. The present case reports describe the successful management of the impacted permanent maxillary central incisor positioned high in the vestibule. A combination of surgical and orthodontic techniques was employed to improve treatment outcome with greater hard and soft tissue preservation and to prevent psychological problems. In the surgical phase, supernumerary teeth and dentigerous cyst were removed. Subsequently traction was employed by bonding bracket on the labial surface using closed and open eruption techniques. Successively, fixed orthodontic treatment was started to align permanent maxillary central incisors in an occlusal plane. Thus, combination of surgical and orthodontic method can be the treatment of choice over surgical extraction, implant placement, and surgical repositioning.

  14. [Diagnosis and treatment of supernumerary teeth in the premaxillary region: a literature review].

    Science.gov (United States)

    Ratson, T

    2013-01-01

    Supernumerary teeth are more frequently located in the premaxillary region. Mesiodentes are the most common supernumerary teeth, occurring in 0.15% to 1.9% of the population. Supernumerary teeth are frequently diagnosed in a random radiograph, or after clinical symptoms appear. The majority of the complications consist of delayed or ectopic eruption of the permanent incisors. It is important for the clinician to be aware of the phenomenon and its implications, in order to diagnose it as early as possible. Extraction of the supernumerary teeth in the late mixed dentition, will minimize the chances of damaging the adjacent permanent teeth, but will reduce the possibility of spontaneous eruption of an impacted permanent incisor. Extraction in the early mixed dentition can expedite the eruption of the permanent incisor, although it may involve sedation or general anesthesia, due to lack of cooperation in the young patient. Because to the risk of uneruption of the permanent impacted incisor, exposure of the teeth and bonding a ligature or bracket at the same procedure, and providing a possibility for the dentist to make the incisor erupt after the first operation, should the incisor not erupt spontaneously. Treating these cases require the cooperation of pediatric dentist, orthodontic and dental surgeon, and sometimes the involvement of an anesthesiologist.

  15. Nonsyndromic Bilateral Multiple Impacted Supernumerary Mandibular Third Molars: A Rare and Unusual Case Report

    Directory of Open Access Journals (Sweden)

    G. Siva Prasad Reddy

    2013-01-01

    Full Text Available A supernumerary tooth is that which is present additionally to the normal series and can be found in any region of the dental arch. An impacted tooth is defined as the one which is embedded in the alveolus, so that its eruption is prevented, or the tooth is locked in position by bone or the adjacent teeth. The occurrence of multiple supernumerary teeth in only one patient in the absence of an associated systemic condition or syndrome is considered as a rare phenomenon. The occurrence of supernumerary teeth in the lower molar region is rare. A prevalence of less than 2% of cases occurring in this region has been estimated. Their occurrence presents a clinical problem for orthodontists and oral surgeons. The cause, frequency, complications, and surgical operation of impacted teeth are always interesting subjects for study and research. An impacted tooth can result in caries, pulp disease, periapical and periodontal disease, temporomandibular joint disorder, infection of the fascial space, root resorption of the adjacent tooth, and even oral and maxillofacial tumours. The management of impacted wisdom teeth has changed over the past 20 years from removal of nonsymptomatic third molars to simple observation. The aim of this paper is to present a rare case of bilateral multiple impacted supernumerary mandibular third molars.

  16. Hemangioendothelioma of bone in a patient with a constitutional supernumerary marker

    DEFF Research Database (Denmark)

    Rogatto, S R; Rainho, C A; Zhang, Z M

    1999-01-01

    A 13-year old girl was diagnosed as having a bone hemangioendothelioma. Cytogenetic studies identified the presence of a small supernumerary marker chromosome in this patient. Classical cytogenetic methods using G-, C-, Ag-NOR-banding were supplemented by spectral karyotyping (SKY) and fluorescen...

  17. Multidisciplinary management of impacted central incisors due to supernumerary teeth and an associated dentigerous cyst

    Science.gov (United States)

    Kalaskar, Ritesh R.; Kalaskar, Ashita R.

    2011-01-01

    Supernumerary teeth are the most common developmental dental anomaly resulting from hyperactivity of dental lamina, dichotomy, environmental factor, or polygenetic process of atavism. Supernumerary teeth present classical oral complication such as impaction of adjacent teeth, crowding, diastema formation, rotation, displacement of teeth, and occlusal interference. A dentigerous cyst associated with anterior supernumerary teeth (mesiodens) is rare and accounts for 5% of all dentigerous cysts. The present case reports describe the successful management of the impacted permanent maxillary central incisor positioned high in the vestibule. A combination of surgical and orthodontic techniques was employed to improve treatment outcome with greater hard and soft tissue preservation and to prevent psychological problems. In the surgical phase, supernumerary teeth and dentigerous cyst were removed. Subsequently traction was employed by bonding bracket on the labial surface using closed and open eruption techniques. Successively, fixed orthodontic treatment was started to align permanent maxillary central incisors in an occlusal plane. Thus, combination of surgical and orthodontic method can be the treatment of choice over surgical extraction, implant placement, and surgical repositioning. PMID:22114457

  18. Genome-wide genetic dissection of supernumerary spikelet and related traits in common wheat

    Science.gov (United States)

    Branched spike or supernumerary spikelet (SS) is a naturally occurring variant in wheat and holds great potential for increasing the number of grains per spike, and ultimately, increasing wheat yield. However, detailed knowledge of the molecular basis of spike branching in common wheat is lacking. I...

  19. Saturn's Rings

    Science.gov (United States)

    Cuzzi, J. N.

    2014-12-01

    The rings are changing before our eyes; structure varies on all timescales and unexpected things have been discovered. Many questions have been answered, but some answers remain elusive (see Cuzzi et al 2010 for a review). Here we highlight the major ring science progress over the mission to date, and describe new observations planned for Cassini's final three years. Ring Composition and particle sizes: The rings are nearly all water ice with no other ices - so why are they reddish? The C Ring and Cassini Division are "dirtier" than the more massive B and A Rings, as shown by near-IR and, recently, microwave observations. Particle sizes, from stellar and radio occultations, vary from place to place. Ring structure, micro and macro: numerous spiral density waves and ubiquitous "self-gravity wakes" reveal processes which fostered planet formation in the solar system and elsewhere. However, big puzzles remain regarding the main ring divisions, the C Ring plateau structures, and the B Ring irregular structure. Moonlets, inside and out, seen and unseen: Two gaps contain sizeable moonlets, but more gaps seem to contain none; even smaller embedded "propeller" objects wander, systematically or randomly, through the A ring. Rubble pile ringmoons just outside the rings may escaped from the rings, and the recently discovered "Peggy" may be trying this as we watch. Impact bombardment of the rings: Comet fragments set the rings to rippling on century-timescales, and boulders crash through hourly; meanwhile, the constant hail of infalling Kuiper belt material has a lower mass flux than previously thought. Origin and Age of the Rings: The ring mass and bombardment play key roles. The ring mass is well known everywhere but in the B Ring (where most of it is). New models suggest how tidal breakup of evolving moons may have formed massive ancient rings, of which the current ring is just a shadow. During its last three years, the Cassini tour profile will allow entirely new

  20. Protostylid: As never reported before! A unique case with variation

    Directory of Open Access Journals (Sweden)

    Vela D Desai

    2016-01-01

    Full Text Available Human jaw and teeth display a high degree of morphological individuality as they represent personal, familial, and population characteristics and one among them are cuspal variations. A protostylid is a supernumerary or accessory cusp located on the mesiobuccal surface of the mandibular molars that seldom pose problems. A forensic odontologist may find significant interest in its classification and identification among victims of mass causalties and bite marks on living and nonliving objects. The authors here are reporting a case of protostylid with a unique presentation which, to best of our knowledge is not reported so far.

  1. Vortex rings

    Energy Technology Data Exchange (ETDEWEB)

    Akhmetov, D.G. [Lavrentiev Institute of Hydrodynamics, Novosibirsk (Russian Federation)

    2009-07-01

    This book presents a comprehensive coverage of the wide field of vortex rings. The book presents the results of systematic experimental investigations, theoretical foundation, as well as the practical applications of vortex rings, such as the extinction of fires at gushing gas and oil wells. All the basic properties of vortex rings as well as their hydrodynamic structures are presented. Special attention is paid to the formation and motion of turbulent vortex rings. (orig.)

  2. Ring theory

    CERN Document Server

    Rowen, Louis H

    1991-01-01

    This is an abridged edition of the author's previous two-volume work, Ring Theory, which concentrates on essential material for a general ring theory course while ommitting much of the material intended for ring theory specialists. It has been praised by reviewers:**""As a textbook for graduate students, Ring Theory joins the best....The experts will find several attractive and pleasant features in Ring Theory. The most noteworthy is the inclusion, usually in supplements and appendices, of many useful constructions which are hard to locate outside of the original sources....The audience of non

  3. Surgical management of impacted incisors in associate with supernumerary teeth: A combine case report of spontaneous eruption and orthodontic extrusion

    Directory of Open Access Journals (Sweden)

    D Das

    2012-01-01

    Full Text Available Maxillary permanent incisors impaction is not a frequent case in dental practice, but its treatment is challenging because of its importance to facial esthetics. Supernumerary teeth are the main cause of impaction of upper incisors. Supernumerary teeth when present can cause both esthetic and pathologic problems. Early detection of such teeth is most important if complications are to be avoided. In this reported case, the orthopantamogram of a 9-year-old boy revealed two impacted supernumerary teeth in the maxillary anterior region, which was interfering with the eruption of the permanent central incisors. The impacted supernumerary teeth were surgically removed, 11 was repositioned in the arch as it was situated very high in the arch, close to the nasal floor. Twenty-one erupted spontaneously but orthodontic force was applied over 11 to bring it into the occlusion and alignment was achieved with 0.014 mm NiTi wire.

  4. Planetary Rings

    CERN Document Server

    Tiscareno, Matthew S

    2011-01-01

    Planetary rings are the only nearby astrophysical disks, and the only disks that have been investigated by spacecraft. Although there are significant differences between rings and other disks, chiefly the large planet/ring mass ratio that greatly enhances the flatness of rings (aspect ratios as small as 1e-7), understanding of disks in general can be enhanced by understanding the dynamical processes observed at close-range and in real-time in planetary rings. We review the known ring systems of the four giant planets, as well as the prospects for ring systems yet to be discovered. We then review planetary rings by type. The main rings of Saturn comprise our system's only dense broad disk and host many phenomena of general application to disks including spiral waves, gap formation, self-gravity wakes, viscous overstability and normal modes, impact clouds, and orbital evolution of embedded moons. Dense narrow rings are the primary natural laboratory for understanding shepherding and self-stability. Narrow dusty...

  5. Expansion of the Rib Head: A Novel Computed Tomographic Feature of Supernumerary Intrathoracic Ribs.

    Science.gov (United States)

    Kabakus, Ismail Mikdat; Atceken, Zeynep; Ariyurek, Orhan Macit

    2017-02-01

    Intrathoracic ribs are very rare congenital anomalies. Approximately 50 cases have been reported in the literature till date. They are usually present on the right side, between the third and eighth ribs without sex predominance. They may originate from a vertebral body or the proximal or distal part of a rib. In most cases, they are asymptomatic, but they may be associated with developmental abnormalities of ribs and vertebrae. The diagnosis is important to prevent further investigation or intervention. Here we present two rare cases with supernumerary intrathoracic rib and describe a novel sign, namely expansion of the rib head. To the best of our knowledge, this is the shortest supernumerary intrathoracic rib, reported in the literature, on the left side originating from the head of the second rib, which could have been misdiagnosed as osteochondroma due to its atypical features.

  6. Supernumerary Nipples, Congenital Scoliosis, Spina Bifida, Diastematomyelia, and Crossed Renal Ectopia in a child

    Directory of Open Access Journals (Sweden)

    Kiran Panthee

    2016-11-01

    Full Text Available Introduction: Supernumerary nipples are common anomalies which may be associated with several systemic disorders, particularly urinary tract abnormalities.   Case report: Here we report a case of a 4½ year old male presenting to the pediatric out patient clinic with fever for three days and recurrent sinopulmonary infections. The child had supernumerary nipples over the right side with deformed thoracic cage, congenital scoliosis, diastematomyelia, crossed renal ectopia, and spina bifida. All the conditions present together did not match any syndrome reported till date.   Conclusion: This was a rare syndrome and did not match fully with any known syndromes till date. This case warranted further investigation for its definite diagnosis but we do not have resources to that extent.

  7. Recurrent epistaxis caused by an intranasal supernumerary tooth in a young adult

    OpenAIRE

    Al Dhafeeri, Hamed O.; Kavarodi, Abdulmajid; Shaikh, Khalil Al; Bukhari, Ahmed; Hussain, Omair Al; Baramawy, Ahmed El

    2014-01-01

    Patient: Male, 27 Final Diagnosis: Recurrent epistaxis Symptoms: Nasal bleeding Medication: — Clinical Procedure: — Specialty: Pediatrics and Neonatology Objective: Congenital defects/diseases Background: Recurrent epistaxis is a common disorder among children and young adults. We report an unusual cause, intranasal supernumerary tooth causing friction with Little’s area of the nasal septum. Case Report: A 22-year-old male presented with recurrent, mild, unilateral left-sided epistaxis once t...

  8. Bilateral fusion of mandibular second molars with supernumerary teeth: case report

    Directory of Open Access Journals (Sweden)

    Nunes Eduardo

    2002-01-01

    Full Text Available Fusion is a developmental anomaly characterized by the union of two adjacent teeth. In this article we report a rare case of bilateral fusion of permanent mandibular second molars with supernumerary teeth. The rarity with which this entity appears, along with its complex characteristics, often make it difficult to treat. The endodontic management of one tooth is described, as well as the successful treatment of a periradicular lesion.

  9. Mosaic small supernumerary marker chromosome 1 at amniocentesis: prenatal diagnosis, molecular genetic analysis and literature review.

    Science.gov (United States)

    Chen, Chih-Ping; Chen, Ming; Su, Yi-Ning; Huang, Jian-Pei; Chern, Schu-Rern; Wu, Peih-Shan; Su, Jun-Wei; Chang, Shun-Ping; Chen, Yu-Ting; Lee, Chen-Chi; Chen, Li-Feng; Pan, Chen-Wen; Wang, Wayseen

    2013-10-15

    We present prenatal diagnosis and molecular cytogenetic analysis of mosaic small supernumerary marker chromosome 1 [sSMC(1)]. We review the literature of sSMC(1) at amniocentesis and chromosome 1p21.1-p12 duplication syndrome. We discuss the genotype-phenotype correlation of the involved genes of ALX3, RBM15, NTNG1, SLC25A24, GPSM2, TBX15 and NOTCH2 in this case.

  10. Molecular cytogenetic analysis and clinical manifestations of a case with de novo mosaic ring chromosome 7

    Directory of Open Access Journals (Sweden)

    Fang Jye-Siung

    2011-02-01

    Full Text Available Abstract Aim Clinical and molecular cytogenetic investigations of a newborn girl exhibiting facial dysmorphism with developmental delay. Methods Phenotypic evaluation was first applied to examine the proband's developmental status. Computed tomography and colour transcranial Doppler were used then to investigate her brain structure and function. Subsequently, chromosomal abnormalities were examined by karyotyping and fluorescent in situ hybridization was performed to investigate size of fragments lost at the two distal ends of the ring chromosome 7. In addition, multicolour banding was applied to rule out structural rearrangement occurs in between the ring chromosome 7. Results The proband was born with mosaic supernumerary ring chromosome 7, without a normal karyotype detected in the peripheral blood lymphocytes. The distal arm of chromosome 7p (at least 255 kb from the telomere was part of an extra ring chromosome 7. In addition, the distal arm of 7q, at least 8 kb from the telomere, was missing. There was no other chromosomal rearrangement detected by multicolour banding. Interpretation This is the 19th reported case of complete ring chromosome 7 mosaicism and the first survived case with mosaic supernumerary ring 7 without a normal karyotype detected in the peripheral lymphocytes.

  11. Existence of inelastic supernumerary nuclear rainbow in 16O+12C scattering

    Science.gov (United States)

    Ohkubo, S.; Hirabayashi, Y.; Ogloblin, A. A.

    2017-08-01

    The existence of a supernumerary nuclear rainbow in inelastic scattering is reported. This is done by studying inelastic 16O scattering from 12C, exciting the 2+ (4.44 MeV) state of 12C and elastic scattering at the incident energies in the range 124-200 MeV, using the coupled channels method. An extended double folding potential is used. This is derived from realistic wave functions for 12C and 16O calculated with a microscopic α cluster model and a finite-range density-dependent nucleon-nucleon force. Excitations to the 2+ (4.44 MeV), 3- (9.64 MeV), and 4+ (14.08 MeV) states of 12C, and the 3- (6.13 MeV) and 2+ (6.92 MeV) states of 16O are included in the coupled channels calculations. The emergence of the supernumerary bow is understood by the properties of both the Luneburg-lens-like potential in the internal region and diffuse attraction in the outer region. The existence of a supernumerary rainbow for inelastic scattering in addition to the existence of a dynamically created secondary rainbow and a dynamically refracted primary rainbow for elastic scattering, which are not observed in meteorological rainbows, further deepens the understanding of nuclear rainbows.

  12. Under your nose: a rare finding during dissection provides insights into maxillary supernumerary teeth.

    Science.gov (United States)

    Redwood, C; Townsend, G C; Ghabriel, M; Brook, A H

    2014-09-01

    A supernumerary tooth was found during anatomical dissection. The position of this tooth, still impacted in the maxilla, and the associated pathology make this a rare case. During dissection by dental students of the sagittally-sectioned head of a cadaver, a supernumerary tooth was identified in the mid-palatal area. Further dissection revealed a swelling with a thin bony covering related to the crown of the tooth. The maxilla was removed en bloc and radiographic examination, CT scanning, electron microscopy and histology were undertaken. The tooth had a crenulated occlusal surface and a single root. It was 25 mm posterior to the root apex of the permanent upper central incisor. The swelling, confirmed by radiographs and CT imaging to be associated with the crown, occupied approximately one-third of the maxillary sinus. The 3D shape of the cystic lesion was visualized by a composite digital movie. The crown form, position of the tooth and the associated dentigerous cyst suggested it was a palatally developing supernumerary premolar which had been displaced to the palatal midline by the expanding cyst. This rare case highlights the learning and teaching opportunities available during dissection, showing important variations in both development and clinical anatomy. © 2014 Australian Dental Association.

  13. The Multidisciplinary Management of Fused Maxillary Lateral Incisor with a Supernumerary Tooth in Cleft Lip Adolescence

    Directory of Open Access Journals (Sweden)

    Ahmet Yagci

    2014-01-01

    Full Text Available Fusion, an uncommon anomaly of the hard dental tissues, is potentially the cause of clinical problems related to esthetics, tooth spacing, and other periodontal complications. This paper describes a multidisciplinary approach involving surgical, endodontic, restorative, and orthodontic attention for the successful, functional, and esthetic rehabilitation of a maxillary left lateral incisor fused with a supernumerary tooth in unilateral cleft lip adolescence in contralateral side. After clinical and radiographic examinations, a fusion between the left maxillary lateral incisor and a supernumerary tooth was diagnosed in the patient, and a small connection was detected between the pulp systems of the two root canals. The case reported in this paper presents the successful resolution of a fused maxillary lateral incisor with a supernumerary tooth, using endodontic, surgical, restorative, and orthodontic management. The decision made in extracting or retaining the fused tooth depends on the arch discrepancy and esthetic needs. Future studies, with long-term followup, will be helpful in evaluating the long-term efficacy of the different treatment options.

  14. Planetary Rings

    Science.gov (United States)

    Cuzzi, Jeffrey N.

    1994-01-01

    Just over two decades ago, Jim Pollack made a critical contribution to our understanding of planetary ring particle properties, and resolved a major apparent paradox between radar reflection and radio emission observations. At the time, particle properties were about all there were to study about planetary rings, and the fundamental questions were, why is Saturn the only planet with rings, how big are the particles, and what are they made of? Since then, we have received an avalanche of observations of planetary ring systems, both from spacecraft and from Earth. Meanwhile, we have seen steady progress in our understanding of the myriad ways in which gravity, fluid and statistical mechanics, and electromagnetism can combine to shape the distribution of the submicron-to-several-meter size particles which comprise ring systems into the complex webs of structure that we now know them to display. Insights gained from studies of these giant dynamical analogs have carried over into improved understanding of the formation of the planets themselves from particle disks, a subject very close to Jim's heart. The now-complete reconnaissance of the gas giant planets by spacecraft has revealed that ring systems are invariably found in association with families of regular satellites, and there is ark emerging perspective that they are not only physically but causally linked. There is also mounting evidence that many features or aspects of all planetary ring systems, if not the ring systems themselves, are considerably younger than the solar system

  15. Burnside Rings of Fusion Systems

    DEFF Research Database (Denmark)

    Reeh, Sune Precht

    , and we produce a basis for the Burnside ring that shares properties with the transitive sets for a finite group. We construct a transfer map from the p-local Burnside ring of the underlying p-group S to the p-local Burnside ring of F. Using such transfer maps, we give a new explicit construction...... of Burnside rings given by multiplication with the characteristic idempotent, and we show that this map is the transfer map previously constructed. Applying these results, we show that for every saturated fusion system the ring generated by all (non-idempotent) characteristic elements in the p-local double...... of the characteristic idempotent of F { the unique idempotent in the p-local double Burnside ring of S satisfying properties of Linckelmann and Webb. We describe this idempotent both in terms of fixed points and as a linear combination of transitive bisets. Additionally, using fixed points we determine the map...

  16. SUPRAMITRAL RING

    Directory of Open Access Journals (Sweden)

    Rajesh G

    2011-11-01

    Full Text Available Supra mitral ring is a rare cause for congenital mitral valve obstr uction. The reported incidence of supramitral ring is 0.2-0.4% in general population and 8% in patients with congenital mitral valve disease. The condition is characterized by an abnormal ridge of connective tissue often circumferential in shape ,on the atrial side of the mitral valve encroaching on the orifice of the mitral valve. It may adhere to the leaflets of the valve and restrict their movements. Although a supramitral ring may be rarely nonobstructive, it often results in mitral valve inflow obstruction.

  17. Stability of monocentric and dicentric ring minichromosomes in Arabidopsis.

    Science.gov (United States)

    Yokota, Etsuko; Shibata, Fukashi; Nagaki, Kiyotaka; Murata, Minoru

    2011-11-01

    A dicentric ring minichromosome (miniδ) was identified in transgenic Arabidopsis thaliana and added to a wild type as a supernumerary chromosome. This line is relatively stable and has been maintained for generations, notwithstanding its ring and dicentric structure. To determine the mechanism for stable transmission of miniδ, the structure and behavior of two new types of ring minichromosomes (miniδ1 and miniδ1-1) derived from miniδ were investigated. Fluorescence in situ hybridization analysis revealed that miniδ1 is dicentric just like miniδ, whereas miniδ1-1 is monocentric. The estimated sizes of miniδ1 and miniδ1-1 were 3.8~5.0 and 1.7 Mb, respectively. The sizes of the two centromeres on miniδ1 were identical (ca. 270 kb) and similar to that of miniδ1-1 (ca. 250 kb). Miniδ1 was relatively stable during mitosis and meiosis, as is miniδ, whereas miniδ1-1 was unstable during mitosis, and the number of minichromosomes per cell varied. This possibly resulted from misdivision caused by a short centromere on monocentric miniδ1-1. Transmission through the female was quite limited for all three ring minichromosomes (0-3.2%), whereas that through the male was relatively high (15.4-27.3%) compared with that of other supernumerary chromosomes in Arabidopsis. Ring structure without telomeres itself seems not to limit the female transmission.

  18. Prevalence of supernumerary teeth in permanent dentition among patients attending a dental college in South Kerala: A pilot study

    Directory of Open Access Journals (Sweden)

    Devi Gopakumar

    2014-01-01

    Full Text Available Background: Supernumerary teeth are excess number of teeth formed as a result of disturbances occurring during odontogenesis. The objective of the study was to investigate the prevalence of supernumerary teeth in permanent dentition among patients attending a dental college in South Kerala. Materials and Methods: In this study, 11,141 subjects attending the out-patient department of PMS College of Dental Science and Research, Thiruvananthapuram, Kerala were examined for supernumerary teeth like mesiodens, paramolars, distomolars, third premolars, second laterals, and odontomes during the period May 2012-May 2013. Ethical clearance was obtained from the institutional ethical committee for the study. Results: The study showed a prevalence of 0.39% and a sex distribution of M:F equal to 2:1. The incidence of supernumerary teeth found was as follows: mesiodens (0.14%, paramolars (0.13%, third premolar (0.04%, distomolar (0.03%, extralateral (0.02%, and odontome (0.03%. The male:female gender predilection was as follows: mesiodens (3:1, paramolars (1.3:1, third premolar (4:1, distomolar (1:2, and odontome (2:1. Conclusion: This study showed a 0.39% prevalence of supernumerary teeth in this population.

  19. Determinantal rings

    CERN Document Server

    Bruns, Winfried

    1988-01-01

    Determinantal rings and varieties have been a central topic of commutative algebra and algebraic geometry. Their study has attracted many prominent researchers and has motivated the creation of theories which may now be considered part of general commutative ring theory. The book gives a first coherent treatment of the structure of determinantal rings. The main approach is via the theory of algebras with straightening law. This approach suggest (and is simplified by) the simultaneous treatment of the Schubert subvarieties of Grassmannian. Other methods have not been neglected, however. Principal radical systems are discussed in detail, and one section is devoted to each of invariant and representation theory. While the book is primarily a research monograph, it serves also as a reference source and the reader requires only the basics of commutative algebra together with some supplementary material found in the appendix. The text may be useful for seminars following a course in commutative ring theory since a ...

  20. Cave Rings

    Science.gov (United States)

    2010-10-13

    hypothesis, that cave rings are formed in the same manner as coffee rings[3], that is, due to the enhanced deposition at the edges of sessile drops ...ring’ is the deposit formed when a sessile drop of a solution containing dissolved particles, such as coffee or salt, dries. This was investigated by...who expanded on Deegan et al.[3] to find an exact form for the evaporation flux over a sessile drop . It turns out that solving 179 for the flux is

  1. Vascular rings.

    Science.gov (United States)

    Backer, Carl L; Mongé, Michael C; Popescu, Andrada R; Eltayeb, Osama M; Rastatter, Jeffrey C; Rigsby, Cynthia K

    2016-06-01

    The term vascular ring refers to congenital vascular anomalies of the aortic arch system that compress the esophagus and trachea, causing symptoms related to those two structures. The most common vascular rings are double aortic arch and right aortic arch with left ligamentum. Pulmonary artery sling is rare and these patients need to be carefully evaluated for frequently associated tracheal stenosis. Another cause of tracheal compression occurring only in infants is the innominate artery compression syndrome. In the current era, the diagnosis of a vascular ring is best established by CT imaging that can accurately delineate the anatomy of the vascular ring and associated tracheal pathology. For patients with a right aortic arch there recently has been an increased recognition of a structure called a Kommerell diverticulum which may require resection and transfer of the left subclavian artery to the left carotid artery. A very rare vascular ring is the circumflex aorta that is now treated with the aortic uncrossing operation. Patients with vascular rings should all have an echocardiogram because of the incidence of associated congenital heart disease. We also recommend bronchoscopy to assess for additional tracheal pathology and provide an assessment of the degree of tracheomalacia and bronchomalacia. The outcomes of surgical intervention are excellent and most patients have complete resolution of symptoms over a period of time. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Supernumerary, ectopic tooth in the maxillary antrum presenting with recurrent haemoptysis

    Directory of Open Access Journals (Sweden)

    Hameed Anam

    2010-11-01

    Full Text Available Abstract Background Ectopic eruption of teeth in non-dental sites is a rare phenomenon and can present in a variety of ways such as chronic or recurrent sinusitis, sepsis, nasolacrimal duct obstruction, headaches, ostiomeatal complex disease and facial numbness. However, presentation of such patients with recurrent haemoptysis has not been described in the literature so far. We have described a case of an ectopic, supernumerary molar tooth in the maxillary antrum in a patient who initially presented with haemoptysis. Case presentation A 45-year-old male presented with a 2-month history of episodic haemoptysis. A pedunculated growth from the inferior nasal turbinate was seen with fibre-optic visualization. Although the patient was empirically started on antibiotic and anti-allergic therapy, there was no improvement after a few weeks and the patient had recurrent episodes of haemoptysis. Fibre-optic visualization was repeated showing bilateral osteomeatal erythema. Computed tomography scan of the paranasal sinuses demonstrated complete opacification of the left maxillary antrum along with a focal area of density comparable to bone. An ectopic, supernumerary molar tooth was found in the left maxillary antrum on endoscopic examination and subsequently removed. In addition, copious purulent discharge was seen. Post-operatively, the patient was treated with a 10-day course of oral amoxicillin-clavulanate. On follow-up, he reported resolution of symptoms. Conclusion Recurrent haemoptysis has not been described as a presentation for a supernumerary, ectopic tooth in literature before. We recommend that in patients with sinusitis-type of opacification of maxillary antrum and whose condition is refractory to conventional medical treatment, consideration should be given to the investigation of possible underlying anomalies as the cause of such symptoms. Presence of foreign bodies and ectopic teeth in paranasal sinuses can be reliably excluded with the use

  3. Supernumerary, ectopic tooth in the maxillary antrum presenting with recurrent haemoptysis.

    Science.gov (United States)

    Saleem, Taimur; Khalid, Umair; Hameed, Anam; Ghaffar, Shehzad

    2010-11-11

    Ectopic eruption of teeth in non-dental sites is a rare phenomenon and can present in a variety of ways such as chronic or recurrent sinusitis, sepsis, nasolacrimal duct obstruction, headaches, ostiomeatal complex disease and facial numbness. However, presentation of such patients with recurrent haemoptysis has not been described in the literature so far. We have described a case of an ectopic, supernumerary molar tooth in the maxillary antrum in a patient who initially presented with haemoptysis. A 45-year-old male presented with a 2-month history of episodic haemoptysis. A pedunculated growth from the inferior nasal turbinate was seen with fibre-optic visualization. Although the patient was empirically started on antibiotic and anti-allergic therapy, there was no improvement after a few weeks and the patient had recurrent episodes of haemoptysis. Fibre-optic visualization was repeated showing bilateral osteomeatal erythema. Computed tomography scan of the paranasal sinuses demonstrated complete opacification of the left maxillary antrum along with a focal area of density comparable to bone. An ectopic, supernumerary molar tooth was found in the left maxillary antrum on endoscopic examination and subsequently removed. In addition, copious purulent discharge was seen. Post-operatively, the patient was treated with a 10-day course of oral amoxicillin-clavulanate. On follow-up, he reported resolution of symptoms. Recurrent haemoptysis has not been described as a presentation for a supernumerary, ectopic tooth in literature before. We recommend that in patients with sinusitis-type of opacification of maxillary antrum and whose condition is refractory to conventional medical treatment, consideration should be given to the investigation of possible underlying anomalies as the cause of such symptoms. Presence of foreign bodies and ectopic teeth in paranasal sinuses can be reliably excluded with the use of appropriate radiological imaging and endoscopic examination.

  4. Multiple bilateral supernumerary mandibular premolars in a non-syndromic patient with associated orthokeratised odontogenic cyst- A case report and review of literature

    Directory of Open Access Journals (Sweden)

    Vikrant O Kasat

    2012-01-01

    Full Text Available Multiple supernumerary teeth are very rare, accounting for less than 1% of cases. They are commonly associated with syndromes like Gardner′s syndrome and cleidocranial dysostosis and cleft lip and palate. Non-syndromic multiple supernumerary teeth have a predilection to occur in the mandibular premolar region. Orthokeratinized odontogenic cyst (OOC is a relatively uncommon developmental cyst comprising about 10% of the cases that had been previously implied as odontogenic keratocysts. More than half of the cases of OOC are associated with impacted tooth; but not a single case of OOC associated with supernumerary teeth is reported. Hence, the purpose of this article is to report the first case of multiple supernumerary mandibular premolars associated with OOC in a 35-year-old male and to review the literature associated with multiple bilateral supernumerary mandibular premolars.

  5. Small supernumerary marker chromosomes (sSMC) in humans; are there B chromosomes hidden among them

    OpenAIRE

    Ogilvie Caroline; Kosyakova Nadezda; Mrasek Kristin; Liehr Thomas; Vermeesch Joris; Trifonov Vladimir; Rubtsov Nikolai

    2008-01-01

    Abstract Background Small supernumerary marker chromosomes (sSMC) and B-chromosomes represent a heterogeneous collection of chromosomes added to the typical karyotype, and which are both small in size. They may consist of heterochromatic and/or euchromatic material. Also a predominance of maternal transmission was reported for both groups. Even though sSMC and B-chromosomes show some similarity it is still an open question if B-chromosomes are present among the heterogeneous group of sSMC. Ac...

  6. A comparison between various radiological techniques in the localization and analysis of impacted and supernumerary teeth

    Directory of Open Access Journals (Sweden)

    Christoph M Ziegler

    2013-01-01

    Full Text Available Background and Objectives: An increasing number of different types of commercial cone-beam computed tomography (CBCT devices are available for three-dimensional (3D imaging in the field of dental and maxillofacial radiology. When removing impacted or supernumerary teeth, surgical teams often operate adjacent significant anatomical structures such as nerves, vessels, adjacent teeth roots, and paranasal sinuses. It is therefore important to choose the appropriate surgical approach to avoid iatrogenic damage to the essential anatomical neighbouring structures. CBCT, also called digital volume tomography (DVT, can visualize impacted and supernumerary teeth in all standard planes, as well as multisectional 3D views. These devices have shown to be highly beneficial in the assessment of small bony lesions and maxillofacial injuries. However, it is still necessary to determine the effectiveness of such devices in the assessment of impacted and supernumerary teeth, in comparison to the conventional radiological methods of intraoral X-rays and panoramic X-rays. Materials and Methods: During a period of 2 years, a total of 61 patients of whom majority had impacted teeth or supernumerary elements in the frontal maxillary region were studied with CBCT and treated at the St. Olavs University Hospital. Patients were referred to our Department of Oral and Maxillofacial Surgery with both conventional and digital intraoral X-rays and/or panoramic X-rays. None had any acute infections or odontogenic abscesses, and most presented with asymptomatic impacted tooth. A comparison between the preoperative conventional and the CBCT images, the resulting diagnoses, and the intraoperative findings as "gold standard" were made and recorded in a compiled scoring sheet. The objects of interest were researched with the magnification method. Each patient was identified only with a patient number. Results: In contrast to the conventional X-rays, the pre-surgical evaluation with

  7. Newborn with Supernumerary Marker Chromosome Derived from Chromosomes 11 And 22- A Case Report.

    Science.gov (United States)

    Vahidi Mehrjardi, Mohammad Yahya; Dehghan Tezerjani, Masoud; Nori-Shadkam, Mahmoud; Kalantar, Seyed Mehdi; Dehghani, Mohammadreza

    2016-03-01

    The interpretation of supernumerary chromosome is important for genetic counseling and prognosis. Here, we used SNP array and conventional karyotyping method to identify a denovo marker chromosome originated from chromosome 22 and 11 in a newborn transferred to the Neonatal Intensive Care Unit of Shahid Sadoughi Hospital in 2015. Clinical abnormalities identified in the newborn were dysmorphic face, intrauterine growth retardation, atrial septal defect (ASD), the hypoplasia of corpus callosum and septum pellucidum. These clinical abnormalities can be related to this marker, and it may help genetic counselor for predicting abnormality risk in susceptible individuals as well as prenatal diagnosis.

  8. Dioctophyme renale Goeze, 1782 in a cat with a supernumerary kidney

    Directory of Open Access Journals (Sweden)

    Daniela Pedrassani

    Full Text Available This study reports a case of parasitism by Dioctophyme renale in a supernumerary kidney and abdominal cavity of a female cat in Brazil. The three-year-old cat of indeterminate breed presented abdominal distension and was taken to the University of Contestado Veterinary Hospital in Canoinhas, state of Santa Catarina, since the owner suspected pregnancy. An ultrasound scan did not confirm pregnancy but revealed parasitism in the kidney. This case is worth reporting because domestic cats are rarely hosts of this nematode species.

  9. Dioctophyme renale Goeze, 1782 in a cat with a supernumerary kidney.

    Science.gov (United States)

    Pedrassani, Daniela; Wendt, Hamilton; Rennau, Erley Alexandre; Pereira, Samuel Tibes; Wendt, Simone Balão Taques

    2014-03-01

    This study reports a case of parasitism by Dioctophyme renale in a supernumerary kidney and abdominal cavity of a female cat in Brazil. The three-year-old cat of indeterminate breed presented abdominal distension and was taken to the University of Contestado Veterinary Hospital in Canoinhas, state of Santa Catarina, since the owner suspected pregnancy. An ultrasound scan did not confirm pregnancy but revealed parasitism in the kidney. This case is worth reporting because domestic cats are rarely hosts of this nematode species.

  10. Mandibular midline supernumerary tooth associated with agenesis of permanent central incisors: a diagnostic conundrum.

    Science.gov (United States)

    Marya, Charu Mohan; Sharma, Gaurav; Parashar, Vijay P; Dahiya, Vandana; Gupta, Anil

    2012-01-01

    Concomitant hypo-hyperdontia is a rare mixed numeric anomalous condition. The presence of this condition in the same area of dental arch and specifically in the mandibular anterior region is reported very infrequently. This case report presents a case of 20 years old male with congenitally missing permanent mandibular central incisors in conjunction with a mandibular midline supernumerary tooth. Only 3 cases have been documented in English literature till date. The article focuses on the review of mandibular mesiodens and the clarity regarding the usage of the terminology "mesiodens".

  11. Pindborg tumor arising in association with an impacted supernumerary tooth in the anterior maxilla.

    Science.gov (United States)

    Waingade, Manjushri; Gawande, Pushkar; Aditya, Amita; Medikeri, Raghavendra S

    2014-06-01

    Pindborg tumor/Calcifying Epithelial Odontogenic Tumor (CEOT) is a benign epithelial odontogenic tumor which shows locally aggressive behavior and accounts for less than 1% of all odontogenic tumors. The most frequent location is the mandibular premolar and molar area; less frequently the lesion is found in the maxilla. Since histopathology remains the main method for definitive diagnosis, this lesion presents an enigma to a clinician when lesions occur in atypical locations. The authors report a case of CEOT in the maxillary anterior region associated with an impacted supernumerary tooth (mesiodens).

  12. Prevalence and characterıstıcs of supernumerary teeth in a child population from Central Anatolıa - Turkey.

    Science.gov (United States)

    Arikan, Volkan; Ozgul, Betul Memis; Firdevs, Tulga O Z

    2013-12-01

    This article aimed to characterize the incidence of supernumerary teeth in Turkish children according to sex, location, number and morphology and to explore possible correlations between these variables. The study population comprised 7,551 non-syndromic patients aged 3-16 years who applied for routine check-ups at the Ankara University Department of Pediatric Dentistry between January 2009 and January 2010. The population included children in deciduous, mixed and permanent dentition. Both clinical and radiographic examinations were conducted. Demographic variables (age, sex) as well as number, location (maxilla or mandible), position, type and morphology of supernumeraries were recorded for all patients with supernumerary teeth. Supernumerary teeth with odontomes were also noted. Of the 7,551 patients examined, supernumerary teeth were detected in 74 patients (0.98%). Of these, 48 were male and 26 were female (male-to-female ratio: 1.84:1). A total of 84 supernumerary teeth were detected, 80 (95.2%) of which were permanent teeth and 4 (4.8%) of which were deciduous teeth (n=4). Most supernumerary teeth (n=59, 70.2%) were located in the maxillary arch. The most common supernumerary teeth were mesiodens (36.9%), followed by supernumerary teeth located in the maxillary incisor region (33.3%), the mandibular premolar region (17.9%), the mandibular molar region (5.9%), the mandibular incisor region (4.8%) and the mandibular canine region (1.2%). The prevalence of supernumerary teeth was found to be 0.98% and mesiodens was the most frequent type.

  13. 多发性多生牙1例%A case report of multiple supernumerary teeth

    Institute of Scientific and Technical Information of China (English)

    姜华

    2013-01-01

      多生牙的发生率占正常人群的1%~3%。多生牙常见于恒牙列,数目一般多见于1~3颗,5颗以上非常罕见。%Incidence of supernumerary teeth in total normal population is 1%-3%. Supernumerary teeth are com-mon in the permanent dentition, and 1-3 teeth are common, but more than 5 teeth are rare.

  14. Topological rings

    CERN Document Server

    Warner, S

    1993-01-01

    This text brings the reader to the frontiers of current research in topological rings. The exercises illustrate many results and theorems while a comprehensive bibliography is also included. The book is aimed at those readers acquainted with some very basic point-set topology and algebra, as normally presented in semester courses at the beginning graduate level or even at the advanced undergraduate level. Familiarity with Hausdorff, metric, compact and locally compact spaces and basic properties of continuous functions, also with groups, rings, fields, vector spaces and modules, and with Zorn''s Lemma, is also expected.

  15. Ring interferometry

    CERN Document Server

    Malykin, Grigorii B; Zhurov, Alexei

    2013-01-01

    This monograph is devoted to the creation of a comprehensive formalism for quantitative description of polarized modes' linear interaction in modern single-mode optic fibers. The theory of random connections between polarized modes, developed in the monograph, allows calculations of the zero shift deviations for a fiber ring interferometer. The monograph addresses also the

  16. Supernumerary Formation of Olfactory Glomeruli Induced by Chronic Odorant Exposure: A Constructivist Expression of Neural Plasticity

    Science.gov (United States)

    Valle-Leija, Pablo; Blanco-Hernández, Eduardo; Drucker-Colín, Rene; Gutiérrez-Ospina, Gabriel; Vidaltamayo, Roman

    2012-01-01

    It is accepted that sensory experience instructs the remodelling of neuronal circuits during postnatal development, after their specification has occurred. The story is less clear with regard to the role of experience during the initial formation of neuronal circuits, whether prenatal or postnatal, since this process is now supposed to be primarily influenced by genetic determinants and spontaneous neuronal firing. Here we evaluated this last issue by examining the effect that postnatal chronic exposure to cognate odorants has on the formation of I7 and M72 glomeruli, iterated olfactory circuits that are formed before and after birth, respectively. We took advantage of double knock-in mice whose I7 and M72 primary afferents express green fluorescent protein and β-galactosidase, correspondingly. Our results revealed that postnatal odorant chronic exposure led to the formation of permanent supernumerary I7 and M72 glomeruli in a dose and time dependent manner. Glomeruli in exposed mice were formed within the same regions of olfactory bulb and occupy small space volumes compared to the corresponding single circuits in non-exposed mice. We suggest that local reorganization of the primary afferents could participate in the process of formation of supernumerary glomeruli. Overall, our results support that sensory experience indeed instructs the permanent formation of specific glomeruli in the mouse olfactory bulb by means of constructivist processes. PMID:22511987

  17. Non-syndromic multiple impacted supernumerary teeth with peripheral giant cell granuloma

    Directory of Open Access Journals (Sweden)

    Pankaj Bansal

    2011-01-01

    Full Text Available Peripheral giant cell granuloma (PGCG is a relatively frequent benign reactive lesion of the gingiva, originating from the periosteum or periodontal membrane following local irritation or chronic trauma. PGCG manifests as a red-purple nodule located in the region of the gingiva or edentulous alveolar margins. The lesion can develop at any age, although it is more common between the second and third decades of life, and shows a slight female predilection. PGCG is a soft tissue lesion that very rarely affects the underlying bone, although the latter may suffer superficial erosion. A supernumerary tooth is one that is additional to the normal series and can be found in almost any region of the dental arch. These teeth may be single, multiple, erupted or unerupted and may or may not be associated with syndrome. Usually, they cause one or the other problem in eruption or alignment of teeth, but may also present without disturbing the normal occlusion or eruption pattern. Management of these teeth depends on the symptoms. Presented here is a case of PGCG in relation to the lower left permanent first molar with three supernumerary teeth in the mandibular arch but no associated syndrome.

  18. Analyses of 1100 supernumerary teeth in a nonsyndromic Turkish population: A retrospective multicenter study.

    Science.gov (United States)

    Bereket, C; Çakır-Özkan, N; Şener, İ; Bulut, E; Baştan, A İ

    2015-01-01

    The aim of this study was to analyze the clinical and radiological features of supernumerary teeth (ST), record the related complications, and discuss different forms of treatment. A total of 111,293 patients were examined over a 3-year period. The patients' ages and genders, in addition to the number, morphology, location, position, shape, developmental stage, and eruption status of ST and associated complications, were recorded. Among the 111,293 patients, there were 851 (0.76%) patients with 1100 ST. Of these patients, 478 (56.2%) were males, and 373 (43.8%) were females, with a mean age of 22.71. Most of the 1100 ST were located in the maxilla, 437 (39.72%) were a conical shape, with 82.81% of these including a fully developed tooth. A mesiodens was the most common type of supernumerary tooth (n=284, 33.37%), followed by distomolars (n=204, 23.97%) and parapremolars (n=146, 17.16%). Among the 1100 ST, 422 (38.36%) were associated with complications. No previous studies in the literature have examined in detail so many cases with ST. The demographic profile of the patients with ST presented herein provides useful additional epidemiological information.

  19. A rare case of impacted supernumerary premolar causing resorption of mandibular first molar

    Directory of Open Access Journals (Sweden)

    R V Murali

    2015-01-01

    Full Text Available The management of patients with pain in today′s general practice has become a major concern and sometimes this pain is related to some rare causes. A male patient aged 26 years reported with pain in the lower left molar region (36 and then an intra-oral periapical radiograph (IOPA, and orthopantomograph was taken. IOPA revealed the presence of supernumerary premolar causing pressure and root resorption of 36. Also, there was missing 21 and proximal decay in 11. Eleven was treated endodontically, and then bridge was done in relation to 11, 21 and 22. Lower anterior crowding was also present. The treatment plan was to extract 36 followed by orthodontic extrusion of the supernumerary premolar and also the correction of lower anterior crowding. Hidden approach (lingual orthodontics was used as the patient was insisting upon the braces not being seen outside during the course of the treatment. Later all ceramic bridge was done in relation to 11, 21 and 22. Orthodontic tooth extrusion techniques offer excellent treatment options for Partially Impacted tooth. It is a well-documented clinical method for extruding sound tooth material from within the alveolar socket by light forces. The use of lingual technique for forced eruption enhance acceptance of orthodontic treatment by adults. The treatment of a young adult patient illustrates the importance of treatment planning from one discipline to another, communication among team members and the benefits of working together in an interdisciplinary approach

  20. On SAP-rings

    OpenAIRE

    Zhixiang, Wu

    2006-01-01

    The rings whose simple right modules are absolutely pure are called right $SAP$-rings. We give a new characterization of right $SAP$ rings, right $V$ rings, and von Neumann regular rings. We also obtain a new decomposition theory of right selfinjective von Neumann regular rings. The relationships between $SAP$-rings, $V$-rings, and von Neumann regular rings are explored. Some recent results obtained by Faith are generalized and the results of Wu-Xia are strengthened.

  1. Clinical Report of 1 Cases of Monozygotic Twins Supernumerary Teeth%单卵双胞胎兄弟额外牙1例

    Institute of Scientific and Technical Information of China (English)

    杨春敏

    2014-01-01

    额外牙是指牙数目异常,其发生可能来自形成过多的牙蕾,也可能是牙胚分裂而成。临床上最多见的是上前牙区单颗多生牙。单卵双胞胎同患多生牙未见报道,同时含有2颗或多颗多生牙者更少见。近日笔者遇到一对双胞胎兄弟,因上前牙区多生牙影响美观前来就诊,由此正确的诊断及时拔除额外牙具有临床意义。%Supernumerary tooth is tooth abnormalities, which may be derived from the formation of excessive tooth bud, may also be split into tooth germ. Clinical go up to see at most is the anterior teeth area single supernumerary teeth. Monozygotic twins with supernumerary teeth is not reported, while containing two or more supernumerary teeth are more rare. I recently met a pair of twin brothers, because to supernumerary teeth appearance came to visit, report as fol ows now.Because the forward supernumerary teeth af ect the appearance to come round to see a doctor, the clinical significance of the correct diagnosis and timely removal of supernumerary teeth. Report as fol ows now.

  2. Phenotypic Spectrum of 20 Novel Patients With Molecularly Defined Supernumerary Marker Chromosomes 15 and a Review of the Literature

    NARCIS (Netherlands)

    Kleefstra, Tjitske; de Leeuw, Nicole; Wolf, Roy; Nillesen, Willy M.; Schobers, Gaby; Mieloo, Hanneke; Willemsen, Marjolein; Perrotta, Concetta Simona; Poddighe, Pino J.; Feenstra, Ilse; Draaisma, Jos; van Ravenswaaij-Arts, Conny M. A.

    Supernumerary marker chromosomes (SMC) originating from chromosome 15 are the most common SMCs. They encompass clinically irrelevant SMC(15)s containing only heterochromatin and 15p material, and clinically relevant SMC(15)s that consist of both eu- and heterochromatic 15q material. On the basis of

  3. Phenotypic Spectrum of 20 Novel Patients With Molecularly Defined Supernumerary Marker Chromosomes 15 and a Review of the Literature

    NARCIS (Netherlands)

    Kleefstra, Tjitske; de Leeuw, Nicole; Wolf, Roy; Nillesen, Willy M.; Schobers, Gaby; Mieloo, Hanneke; Willemsen, Marjolein; Perrotta, Concetta Simona; Poddighe, Pino J.; Feenstra, Ilse; Draaisma, Jos; van Ravenswaaij-Arts, Conny M. A.

    2010-01-01

    Supernumerary marker chromosomes (SMC) originating from chromosome 15 are the most common SMCs. They encompass clinically irrelevant SMC(15)s containing only heterochromatin and 15p material, and clinically relevant SMC(15)s that consist of both eu- and heterochromatic 15q material. On the basis of

  4. Nuclear Physics Experiments with Ion Storage Rings

    CERN Document Server

    Litvinova, Yu A; Blaum, K; Bosch, F; Brandau, C; Chen, L X; Dillmann, I; Egelhof, P; Geissel, H; Grisenti, R E; Hagmann, S; Heil, M; Heinz, A; Kalantar-Nayestanaki, N; Knöbel, R; Kozhuharov, C; Lestinsky, M; Ma, X W; Nilsson, T; Nolden, F; Ozawa, A; Raabe, R; Reed, M W; Reifarth, R; Sanjari, M S; Schneider, D; Simon, H; Steck, M; Stöhlker, T; Sun, B H; Tu, X L; Uesaka, T; Walker, P M; Wakasugi, M; Weick, H; Winckler, N; Woods, P J; Xu, H S; Yamaguchi, T; Yamaguchi, Y; Zhang, Y H

    2013-01-01

    In the last two decades a number of nuclear structure and astrophysics experiments were performed at heavy-ion storage rings employing unique experimental conditions offered by such machines. Furthermore, building on the experience gained at the two facilities presently in operation, several new storage ring projects were launched worldwide. This contribution is intended to provide a brief review of the fast growing field of nuclear structure and astrophysics research at storage rings.

  5. Giant Rings in the CMB Sky

    CERN Document Server

    Kovetz, Ely D; Itzhaki, Nissan

    2010-01-01

    We find a unique direction in the CMB sky around which giant rings have an anomalous mean temperature profile. This direction is in very close alignment with the afore measured anomalously large bulk flow direction. We argue that a cosmic defect seeded by a pre-inflationary particle could explain the giant rings, the large bulk flow and their alignment.

  6. Fibroadenoma in Axillary Supernumerary Breast in a 17-Year-Old Girl: Case Report.

    Science.gov (United States)

    Surd, Adrian; Mironescu, Aurel; Gocan, Horatiu

    2016-10-01

    Supernumerary breast or polymastia is a well documented anomaly of the breast, and commonly presents along the embryonic milk line extending between the axilla and groin. However, cases of polymastia have been recorded in the face, vulva, and perineum. The clinical significance of these anomalies include their susceptibility to inflammatory and malignant changes, and their association with other congenital anomalies of the urinary and cardiovascular systems. In this article we report a case of fibroadenoma that developed in the supernumerary breast of the right axilla in a 17-year-old girl. It is uncommon to find such palpable masses in young patients. Clinical and sonographic examination of both breasts revealed no abnormalities and no lymph nodes were detected in the axillae or the neck. No associated urologic or cardiovascular abnormalities were found, and the histopathological examination of the excisional biopsy samples showed a well-defined, capsulated intracanalicular type of fibroadenoma similar to that of eutopic mammary tissue. In this report, we describe a rare case of fibroadenoma in an accessory breast in a young woman. There are a fewer than 40 reports in the world about this subject, of which differential diagnoses include: cancer in axillary supernumerary breast, hidradenitis, axillary lymphadenomegaly, lipomas, anexial cutaneous neoplasia, cysts, and phylloides tumor. The combination of clinical examination, ultrasound, and cytology leads to adequate treatment, especially surgical. The diagnosis could be confused because of findings from cytology. In this case, because of the clinical and sonographic findings and multiple differential diagnosis, only the histopathological study was used to confirm the diagnosis. Despite its high sensitivity, cytology has low specificity and could create false positive results. However, atypical lesions can be seen in fibroadenomas, especially in younger patients, pregnant patients, and in patients who use hormonal

  7. Supernumerary rainbows

    Science.gov (United States)

    Sawicki, Mikolaj; Sawicki, Pawel

    2000-01-01

    Late in the afternoon of July 19, 1999, we were able to photograph some very unusual rainbows in the sky over Boulder, Colorado. The picture here shows a primary rainbow, a fainter secondary bow above it, and several pastel-shaded rainbows inside the primary one. While we think we counted as many as four concurrent rainbows in that afternoon, only three of them show up in developed prints.

  8. Paradental cyst associated with supernumerary tooth fused with third molar: A rare case report

    Directory of Open Access Journals (Sweden)

    A Ravi Prakash

    2012-01-01

    Full Text Available Fusion is the union of two tooth buds that are normally separated. Fusion is more frequent in deciduous teeth, particularly in the anterior region. The etiology of fusion is not known. It has been suggested that the pressure of adjacent dental follicles produces their contact and fusion before calcification. There is no difference between men and women in incidence. The term paradental cyst means that such type of cysts that are close proximity with the root of a tooth. A history of recurrent pericoronitis is reported usually and there is often the presence of a communication between the periodontal pocket and the cyst. We present a rare case report where in partially erupted mandibular third molar is fused horizontally with a supernumerary tooth with paradental cyst.

  9. Paradental cyst associated with supernumerary tooth fused with third molar: A rare case report

    Science.gov (United States)

    Prakash, A Ravi; Reddy, P Sreenivas; Rajanikanth, M

    2012-01-01

    Fusion is the union of two tooth buds that are normally separated. Fusion is more frequent in deciduous teeth, particularly in the anterior region. The etiology of fusion is not known. It has been suggested that the pressure of adjacent dental follicles produces their contact and fusion before calcification. There is no difference between men and women in incidence. The term paradental cyst means that such type of cysts that are close proximity with the root of a tooth. A history of recurrent pericoronitis is reported usually and there is often the presence of a communication between the periodontal pocket and the cyst. We present a rare case report where in partially erupted mandibular third molar is fused horizontally with a supernumerary tooth with paradental cyst. PMID:22434950

  10. Cleidocranial dysplasia presenting with retained deciduous teeth and impacted permanent and supernumerary teeth

    Directory of Open Access Journals (Sweden)

    Mahalakshmi Ikkanur Puttaranganaik

    2014-01-01

    Full Text Available Cleidocranial dysplasia is a disease that occurs secondary to a dominant autosomal inheritance. There is no predilection for any genre or ethnic group. As there is a delay in the eruption and/or absence of permanent teeth, the patients usually report to a dental surgeon for replacement of the missing teeth. This condition is characterized by several cranial malformations and underdevelopment, absence of clavicles, and multiple impacted supernumerary and permanent teeth. The diagnosis of the condition is usually based on the presence of the above-mentioned main features and on clinical and familial evidence. Here we report a rare case of cleidocranial dysplasia in a male patient, having most of the characteristic features of this syndrome.

  11. Caries, Periodontal Disease, Supernumerary Teeth and Other Dental Disorders in Swedish Wild Boar (Sus scrofa).

    Science.gov (United States)

    Malmsten, A; Dalin, A-M; Pettersson, A

    2015-07-01

    Between January and December 2013, the dental and periodontal health of 99 Swedish wild boars (Sus scrofa) was investigated. Sampling occurred in conjunction with routine hunting at six large estates in the southern and middle parts of Sweden. All six of the estates use supplemental feeding. The weight of the animals, their sex and their dates of death were noted. Age was estimated using tooth eruption and tooth replacement patterns. The oral cavity was inspected and abnormalities were recorded on a dental chart modified for wild boars. The findings included supernumerary teeth, absence of teeth, mild class II malocclusion, severe tooth wear, periodontitis, calculus, caries, tooth fractures and the presence of enamel defects. Swedish wild boars suffer from different dental lesions and the impact of supplemental feeding on dental and periodontal health is still to be investigated.

  12. Removal of Supernumerary Teeth Utilizing a Computer-Aided Design/Computer-Aided Manufacturing Surgical Guide.

    Science.gov (United States)

    Jo, Chanwoo; Bae, Doohwan; Choi, Byungho; Kim, Jihun

    2017-05-01

    Supernumerary teeth need to be removed because they can cause various complications. Caution is needed because their removal can cause damage to permanent teeth or tooth germs in the local vicinity. Surgical guides have recently been used in maxillofacial surgery. Because surgical guides are designed through preoperative analysis by computer-aided design software and fabricated using a 3-dimensional printer applying computer-aided manufacturing technology, they increase the accuracy and predictability of surgery. This report describes 2 cases of removal of a mesiodens-1 from a child and 1 from an adolescent-using a surgical guide; these would have been difficult to remove with conventional surgical methods. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  13. Atypical supernumerary phantom limb and phantom limb pain in two patients with pontine hemorrhage.

    Science.gov (United States)

    Yoo, Seung Don; Kim, Dong Hwan; Jeong, Yong Seol; Chon, Jinmann; Bark, Jihea

    2011-06-01

    Phantom limbs are usually observed after amputation of extremities. In patients after a stroke, a similar but rarely occurring phenomenon consisting of the patient experiencing the presence of an additional limb has been described. This phenomenon, generally called supernumerary phantom limb (SPL), may be caused by lesions in the right or left cerebral hemisphere, but has been predominantly reported in patients who have had a right hemispheric stroke. We report two cases of atypical SPL and phantom limb pain (PLP) after pontine hemorrhage. The patients were treated conservatively and their symptoms lasted more than 1 month. This is the first report of SPLs after left pontine hemorrhage, and phantom perception and pain lasted longer than those in previously observed cases. Our results indicate that SPL may be more common than reported; therefore, thorough examinations are essential for the care of stroke patients.

  14. Origami rings

    CERN Document Server

    Buhler, Joe; de Launey, Warwick; Graham, Ron

    2010-01-01

    Motivated by a question in origami, we consider sets of points in the complex plane constructed in the following way. Let $L_\\alpha(p)$ be the line in the complex plane through $p$ with angle $\\alpha$ (with respect to the real axis). Given a fixed collection $U$ of angles, let $\\RU$ be the points that can be obtained by starting with $0$ and $1$, and then recursively adding intersection points of the form $L_\\alpha(p) \\cap L_\\beta(q)$, where $p, q$ have been constructed already, and $\\alpha, \\beta$ are distinct angles in $U$. Our main result is that if $U$ is a group with at least three elements, then $\\RU$ is a subring of the complex plane, i.e., it is closed under complex addition and multiplication. This enables us to answer a specific question about origami folds: if $n \\ge 3$ and the allowable angles are the $n$ equally spaced angles $k\\pi/n$, $0 \\le k < n$, then $\\RU$ is the ring $\\Z[\\zeta_n]$ if $n$ is prime, and the ring $\\Z[1/n,\\zeta_{n}]$ if $n$ is not prime, where $\\zeta_n := \\exp(2\\pi i/n)$ is ...

  15. Multi-Stage FE Simulation of Hot Ring Rolling

    NARCIS (Netherlands)

    Wang, C.; Geijselaers, H.J.M.; Boogaard, van den A.H.; Zhang, S.-H.; Liu, X.-H.

    2013-01-01

    As a unique and important member of the metal forming family, ring rolling provides a cost effective process route to manufacture seamless rings. Applications of ring rolling cover a wide range of products in aerospace, automotive and civil engineering industries [1]. Above the recrystallization tem

  16. Autotransplantation of a Supernumerary Tooth to Replace a Misaligned Incisor with Abnormal Dimensions and Morphology: 2-Year Follow-Up

    Directory of Open Access Journals (Sweden)

    R. Ebru Tirali

    2013-01-01

    Full Text Available Autotransplantation is a viable treatment option to restore esthetics and function impaired by abnormally shaped teeth when a suitable donors tooth is available. This paper describes the autotransplantation and 2-year follow-up of a supernumerary maxillary incisor as a replacement to a misaligned maxillary incisor with abnormal crown morphology and size. The supernumerary incisor was immediately autotransplanted into the extraction site of the large incisor and was stabilized with a bonded semirigid splint for 2 weeks. Fixed orthodontic therapy was initiated 3 months after autotransplantation. Ideal alignment of the incisors was accomplished after 6 months along with radiographic evidence of apical closure and osseous/periodontal regeneration. In autogenous tooth transplantation, a successful clinical outcome can be achieved if the cases are selected and treated properly.

  17. Sarjeev′s supernumerary tooth notation system: A universally compatible add-on to the Two-Digit system

    Directory of Open Access Journals (Sweden)

    Sarjeev Singh Yadav

    2013-01-01

    Full Text Available Aim: To give notation for quadrants, tooth position, and the type of supernumerary teeth for both permanent and deciduous dentition. Tooth numbering provides dentists with an essential shortcut in clinical record keeping. Materials and Methods: Three systems are favored worldwide: the Zsigmondy/Palmer system, the Universal system, and the Federation Dentaire Internationale (FDI Two-Digit system. Histories of all tooth-numbering methods were traced and the strengths and deficiencies of each system were reviewed. The FDI Two-Digit system is widely used throughout the world, except USA, and is the only method that makes the visual sense, cognitive sense, and computer sense. Conclusion: On review it was noticed that all tooth notation systems in vogue have a drawback as they do not provide any information or notations for supernumerary teeth such as paramolar, distomolar, mesiodens, and fused teeth.

  18. Sarjeev's supernumerary tooth notation system: a universally compatible add-on to the Two-Digit system.

    Science.gov (United States)

    Yadav, Sarjeev Singh; Sonkurla, Sapna

    2013-01-01

    To give notation for quadrants, tooth position, and the type of supernumerary teeth for both permanent and deciduous dentition. Tooth numbering provides dentists with an essential shortcut in clinical record keeping. Three systems are favored worldwide: the Zsigmondy/Palmer system, the Universal system, and the Federation Dentaire Internationale (FDI) Two-Digit system. Histories of all tooth-numbering methods were traced and the strengths and deficiencies of each system were reviewed. The FDI Two-Digit system is widely used throughout the world, except USA, and is the only method that makes the visual sense, cognitive sense, and computer sense. On review it was noticed that all tooth notation systems in vogue have a drawback as they do not provide any information or notations for supernumerary teeth such as paramolar, distomolar, mesiodens, and fused teeth.

  19. On varieties of rings whose finite rings are determined by their zero-divisor graphs

    CERN Document Server

    Maltsev, Yu N

    2012-01-01

    The zero-divisor graph $\\Gamma(R)$ of an associative ring $R$ is the graph whose vertices are all nonzero zero-divisors (one-sided and two-sided) of $R$, and two distinct vertices $x$ and $y$ are joined by an edge iff either $xy=0$ or $yx=0$. In the present paper, we study some properties of ring varieties where every finite ring is uniquely determined by its zero-divisor graph.

  20. Mechanisms of ring chromosome formation in 11 cases of human ring chromosome 21

    DEFF Research Database (Denmark)

    McGinniss, M J; Kazazian, H H; Stetten, G

    1992-01-01

    We studied the mechanism of ring chromosome 21 (r(21)) formation in 13 patients (11 unique r(21)s), consisting of 7 from five families with familial r(21) and 6 with de novo r(21). The copy number of chromosome 21 sequences in the rings of these patients was determined by quantitative dosage anal...

  1. Formalized Linear Algebra over Elementary Divisor Rings in Coq

    OpenAIRE

    Cano, Guillaume; Cohen, Cyril; Dénès, Maxime; Mörtberg, Anders; Siles, Vincent

    2016-01-01

    International audience; This paper presents a Coq formalization of linear algebra over elementary divisor rings, that is, rings where every matrix is equivalent to a matrix in Smith normal form. The main results are the formalization that these rings support essential operations of linear algebra, the classification theorem of finitely pre-sented modules over such rings and the uniqueness of the Smith normal form up to multiplication by units. We present formally verified algorithms comput-in...

  2. Formalized linear algebra over Elementary Divisor Rings in Coq

    OpenAIRE

    Cano, Guillaume; Cohen, Cyril; Dénès, Maxime; Mörtberg, Anders; Siles, Vincent

    2016-01-01

    International audience; This paper presents a Coq formalization of linear algebra over elementary divisor rings, that is, rings where every matrix is equivalent to a matrix in Smith normal form. The main results are the formalization that these rings support essential operations of linear algebra, the classification theorem of finitely pre-sented modules over such rings and the uniqueness of the Smith normal form up to multiplication by units. We present formally verified algorithms comput-in...

  3. Prime rings with PI rings of constants

    CERN Document Server

    Kharchenko, V K; Rodríguez-Romo, S

    1996-01-01

    It is shown that if the ring of constants of a restricted differential Lie algebra with a quasi-Frobenius inner part satisfies a polynomial identity (PI) then the original prime ring has a generalized polynomial identitiy (GPI). If additionally the ring of constants is semiprime then the original ring is PI. The case of a non-quasi-Frobenius inner part is also considered.

  4. Radical theory of rings

    CERN Document Server

    Gardner, JW

    2003-01-01

    Radical Theory of Rings distills the most noteworthy present-day theoretical topics, gives a unified account of the classical structure theorems for rings, and deepens understanding of key aspects of ring theory via ring and radical constructions. Assimilating radical theory's evolution in the decades since the last major work on rings and radicals was published, the authors deal with some distinctive features of the radical theory of nonassociative rings, associative rings with involution, and near-rings. Written in clear algebraic terms by globally acknowledged authorities, the presentation

  5. Beyond the big five: the Dark Triad and the supernumerary personality inventory.

    Science.gov (United States)

    Veselka, Livia; Schermer, Julie Aitken; Vernon, Philip A

    2011-04-01

    The Dark Triad of personality, comprising Machiavellianism, narcissism, and psychopathy, was investigated in relation to the Supernumerary Personality Inventory (SPI) traits, because both sets of variables are predominantly distinct from the Big Five model of personality. Correlational and principal factor analyses were conducted to assess the relations between the Dark Triad and SPI traits. Multivariate behavioral genetic model-fitting analyses were also conducted to determine the correlated genetic and/or environmental underpinnings of the observed phenotypic correlations. Participants were 358 monozygotic and 98 same-sex dizygotic adult twin pairs from North America. As predicted, results revealed significant correlations between the Dark Triad and most SPI traits, and these correlations were primarily attributable to common genetic and non-shared environmental factors, except in the case of Machiavellianism, where shared environmental effects emerged. Three correlated factors were extracted during joint factor analysis of the Dark Triad and SPI traits, as well as a heritable general factor of personality - results that clarified the structure of the Dark Triad construct. It is concluded that the Dark Triad represents an exploitative and antisocial construct that extends beyond the Big Five model and shares a theoretical space with the SPI traits.

  6. Origin and molecular organization of supernumerary chromosomes of Prochilodus lineatus (characiformes, prochilodontidae) obtained by DNA probes.

    Science.gov (United States)

    Voltolin, Tatiana Aparecida; Laudicina, Alejandro; Senhorini, José Augusto; Bortolozzi, Jehud; Oliveira, Cláudio; Foresti, Fausto; Porto-Foresti, Fábio

    2010-12-01

    In Prochilodus lineatus B-chromosomes are visualized as reduced size extra elements identified as microchromosomes and are variable in morphology and number. We describe the specific total probe (B-chromosome probe) in P. lineatus obtained by chromosome microdissection and a whole genomic probe (genomic probe) from an individual without B-chromosome. The specific B-chromosome was scraped and processed to obtain DNA with amplification by DOP-PCR, and so did the genomic probe DNA. Fluorescence in situ hybridization using the B-chromosome probe labeled with dUTP-Tetramethyl-rhodamine and the genomic probe labeled with digoxigenin-FITC permitted to establish that in this species supernumerary chromosomes with varying number and morphology had different structure of chromatin when compared to that of the regular chromosomes or A complement, since only these extra elements were labeled in the metaphases. The present findings suggest that modifications in the chromatin structure of B-chromosomes to differentiate them from the A chromosomes could occur along their dispersion in the individuals of the population.

  7. An EMG Interface for the Control of Motion and Compliance of a Supernumerary Robotic Finger

    Directory of Open Access Journals (Sweden)

    Irfan Hussain

    2016-11-01

    Full Text Available In this paper, we present an electromyographic (EMG control interface for a supernumerary robotic finger. This novel wearable robot can be used to compensate the missing grasping abilities in chronic stroke patients or to augment human healthy hand so to enhance its grasping capabilities and workspace. The proposed EMG interface controls the motion of the robotic extra finger and its joint compliance. In particular, we use a commercial EMG armband for gesture recognition to be associated with the motion control of the robotic device and surface one channel EMG electrodes interface to regulate the compliance of the robotic device. We also present an updated version of a robotic extra finger where the adduction/abduction motion is realized through ball bearing and spur gears mechanism. We validated the proposed interface with two sets of experiments related to compensation and augmentation. In the first set of experiments, different bi-manual tasks have been performed with the help of the robotic device and simulating a paretic hand. In the second set, the robotic extra finger is used to enlarge the workspace and manipulation capability of healthy hands. In both the sets, the same EMG control interface has been used. The obtained results demonstrate that the proposed control interface is intuitive and can successfully be used for both compensation and augmentation purposes. The proposed approach can be exploited also for the control of different wearable devices that has to actively cooperate with the human limbs.

  8. Array comparative genomic hybridization analysis of small supernumerary marker chromosomes in human infertility.

    Science.gov (United States)

    Guediche, N; Tosca, L; Kara Terki, A; Bas, C; Lecerf, L; Young, J; Briand-Suleau, A; Tou, B; Bouligand, J; Brisset, S; Misrahi, M; Guiochon-Mantel, A; Goossens, M; Tachdjian, G

    2012-01-01

    Small supernumerary marker chromosomes (sSMC) are structurally abnormal chromosomes that cannot be unambiguously identified by conventional banding cytogenetics. This study describes four patients with sSMC in relation with infertility. Patient 1 had primary infertility. His brother, fertile, carried the same sSMC (patient 2). Patient 3 presented polycystic ovary syndrome and patient 4 primary ovarian insufficiency. Cytogenetic studies, array comparative genomic hybridization (CGH) and sperm analyses were compared with cases previously reported. sSMC corresponded to the 15q11.2 region (patients 1 and 2), the centromeric chromosome 15 region (patient 3) and the 21p11.2 region (patient 4). Array CGH showed 3.6-Mb gain for patients 1 and 2 and 0.266-Mb gain for patient 4. Sperm fluorescent in-situ hybridization analyses found ratios of 0.37 and 0.30 of sperm nuclei with sSMC(15) for patients 1 and 2, respectively (P < 0.001). An increase of sperm nuclei with disomy X, Y and 18 was noted for patient 1 compared with control and patient 2 (P < 0.001). Among the genes mapped in the unbalanced chromosomal regions, POTE B and BAGE are related to the testis and ovary, respectively. The implication of sSMC in infertility could be due to duplication, but also to mechanical effects perturbing meiosis.

  9. A clinical, cytogenetic, FISH and molecular study of supernumerary marker 15 chromosomes

    Energy Technology Data Exchange (ETDEWEB)

    Dennis, N.R. [Princess Anne Hospital, Southampton (United Kingdom); Crolla, J.A.; Harvey, J.F. [Salisbury District Hospital (United Kingdom)

    1994-09-01

    We studied 17 patients with supernumerary marker chromosomes shown by fluorescent in situ hybridization (FISH) with the 15-centromere specific probe pTRA-25 to be 15-derived. Genetic constitution of the marker chromosomes was investigated using FISH, Southern blot analysis and PCR for proximal and distal loci on 15q as well as conventional cytogenetics. Eight of the 17 patients were mentally retarded. Six of the eight carried a de novo marker 15 containing one or two doses of loci known to be in or near the Prader-Willi/Angelman (PWS/AS) region, whereas none of the nine non-retarded patients had duplications of this region, and only two of the eight whose parents were available had a de novo marker. None of the mentally retarded patients had PWS or AS. In two retarded patients (one de novo, one familial) there was no duplication of the PWS/AS region. Uniparental disomy affecting the normal 15 homologs was excluded in 10 of the patients, including all eight with mental retardation.

  10. Zika virus causes supernumerary foci with centriolar proteins and impaired spindle positioning

    Science.gov (United States)

    Wolf, Benita; Diop, Fodé; Ferraris, Pauline; Wichit, Sineewanlaya; Busso, Coralie; Missé, Dorothée

    2017-01-01

    Zika virus (ZIKV) causes congenital microcephaly. Although ZIKV can impair cell cycle progression and provoke apoptosis, which probably contributes to disease aetiology through depletion of neural progenitor cells, additional cellular mechanisms may be important. Here, we investigated whether ZIKV infection alters centrosome number and spindle positioning, because such defects are thought to be at the root of inherited primary autosomal recessive microcephaly (MCPH). In addition to HeLa cells, in which centrosome number and spindle positioning can be well monitored, we analysed retinal epithelial cells (RPE-1), as well as brain-derived microglial (CHME-5) and neural progenitor (ReN) cells, using immunofluorescence. We established that ZIKV infection leads to supernumerary foci containing centriolar proteins that in some cases drive multipolar spindle assembly, as well as spindle positioning defects in HeLa, RPE-1 and CHME-5 cells, but not in ReN cells. We uncovered similar phenotypes in HeLa cells upon infection with dengue virus (DENV-2), another flavivirus that does not target brain cells and does not cause microcephaly. We conclude that infection with Flaviviridae can increase centrosome numbers and impair spindle positioning, thus potentially contributing to microcephaly in the case of Zika. PMID:28100662

  11. Clinical impact of somatic mosaicism in cases with small supernumerary marker chromosomes.

    Science.gov (United States)

    Liehr, T; Klein, E; Mrasek, K; Kosyakova, N; Guilherme, R S; Aust, N; Venner, C; Weise, A; Hamid, A B

    2013-01-01

    Somatic mosaicism is present in slightly more than 50% of small supernumerary marker chromosome (sSMC) carriers. Interestingly, non-acrocentric derived sSMC show mosaicism much more frequently than acrocentric ones. sSMC can be present in different mosaic rates, which may go below 5% of the studied cells. Also cryptic mosaicism can be present and mosaics may be differently expressed in different tissues of the body. Even though in the overwhelming majority of the cases somatic sSMC mosaicism has no direct clinical effect, there are also cases with altered clinical outcomes due to mosaicism. Also clinically important is the fact that a de novo sSMC, even present in mosaic, may be a hint of uniparental disomy (UPD). As it is under discussion to possibly replace standard karyotyping by methods like array-CGH, the impracticality of the latter to detect low-level sSMC mosaics and/or UPD has to be considered as well. Overall, sSMC mosaicism has to be studied carefully in each individual case, as it can be extremely informative and of importance, especially for prenatal genetic counseling.

  12. Multiple, supernumerary retained teeth in the course of cleido-cranial dysplasia. A case report.

    Science.gov (United States)

    Lewandowski, Bogumił; Martula-Gala, Katarzyna; Brodowski, Robert; Zych, Barbara

    2015-01-01

    Cleido-cranial dysplasia, often referred to as Scheuthauer-Marie-Sainton syndrome, is an autosomal dominant disorder of the musculo-skeletal system. Patients with cleido-cranial dysplasia are characterized by short stature, frequent varus or valgus hip, kyphoscoliosis, underdevelopment of the scapulas and the sternum, incorrect number of ribs. The most characteristic feature is unilateral or bilateral, partial or total underdevelopment of clavicles. Mental development is not affected in this syndrome. Malocclusion, occlusal irregularities, multiple supernumerary teeth, impacted teeth, and persistent milk teeth are found in the stomatognathic system. Teeth often have abnormal anatomy. Gothic palate, cleft hard and soft palate are diagnosed. The aim of this paper is to present a case of a 12-year-old boy diagnosed with irregularities in the masticatory system involving an additional number of retained teeth. The boy was referred by an orthodontist for surgical and orthodontic team therapy. The case presented confirms the observations of other authors that only the multi-specialty collaboration of a pediatrician, a geneticist, an orthopedist, an orthodontist, a maxillofacial surgeon, an implant prosthetic surgeon and a physiotherapist can provide proper diagnosis and treatment.

  13. Clinical management of a fused mandibular lateral incisor with supernumerary tooth: A case report

    Directory of Open Access Journals (Sweden)

    Seda Aydemir

    2016-01-01

    Full Text Available The purpose of this report is to present a rare case of a fused mandibular lateral incisor with supernumerary tooth with a follow-up for 18-months. A 35-year-old female patient was referred to our clinic with an extraoral sinus tract in the chin. The intraoral diagnosis revealed the fusion of her mandibular lateral incisors. Vitality pulp tests were negative for mandibular right central and lateral incisors. Radiographic examinations showed a fused tooth with two separate pulp chambers, two distinct roots, and two separate root canals. There were also periapical lesion of fused teeth and mandibular right central incisor, so endodontic treatment was carried out the related teeth. Radiographic examination revealed a complete healing of the lesion postoperatively at the end of 18-months. This paper reports the successful endodontic and restorative treatment of unilateral fused incisors. Because of the abnormal morphology of the crown and the complexity of the root canal system in fused teeth, treatment protocols require special attention.

  14. Ownership and Agency of an Independent Supernumerary Hand Induced by an Imitation Brain-Computer Interface.

    Directory of Open Access Journals (Sweden)

    Luke Bashford

    Full Text Available To study body ownership and control, illusions that elicit these feelings in non-body objects are widely used. Classically introduced with the Rubber Hand Illusion, these illusions have been replicated more recently in virtual reality and by using brain-computer interfaces. Traditionally these illusions investigate the replacement of a body part by an artificial counterpart, however as brain-computer interface research develops it offers us the possibility to explore the case where non-body objects are controlled in addition to movements of our own limbs. Therefore we propose a new illusion designed to test the feeling of ownership and control of an independent supernumerary hand. Subjects are under the impression they control a virtual reality hand via a brain-computer interface, but in reality there is no causal connection between brain activity and virtual hand movement but correct movements are observed with 80% probability. These imitation brain-computer interface trials are interspersed with movements in both the subjects' real hands, which are in view throughout the experiment. We show that subjects develop strong feelings of ownership and control over the third hand, despite only receiving visual feedback with no causal link to the actual brain signals. Our illusion is crucially different from previously reported studies as we demonstrate independent ownership and control of the third hand without loss of ownership in the real hands.

  15. Unusual small supernumerary marker chromosome (sSMC) 9 in a Klinefelter patient.

    Science.gov (United States)

    Liehr, T; Mrasek, K; Starke, H; Claussen, U; Schreiber, G

    2005-01-01

    Small supernumerary marker chromosomes (sSMC) are small additional chromosomes characterizable for their origin only by molecular cytogenetic approaches. sSMC have been reported previously in four types of syndromes associated with chromosomal imbalances: in approximately 150 cases with Turner syndrome, 26 cases with Down syndrome and only one case each with Klinefelter syndrome and "Triple-X"-syndrome. Here we report the second case with an sSMC detected in addition to a Klinefelter karyotype. Molecular cytogenetics applying centromere-specific multicolor FISH (cenM-FISH) and a specific subcentromere-specific (subcenM-FISH) probe set characterized the sSMC as a dic(9)(:p12-->q11.1::q11.1--> p11.1:). The reported patient was described with hypogonadism, gynaecomastia plus a bronchial carcinoma. The patient's clinical features are discussed in connection with other Klinefelter cases and possible consequences of presence of the sSMC(9). Furthermore, a suggestion is made for the mode of sSMC-formation in this case.

  16. Supernumerary marker chromosomes derived from chromosome 6: cytogenetic, molecular cytogenetic, and array CGH characterization.

    Science.gov (United States)

    Huang, Bing; Pearle, Phyllis; Rauen, Katherine A; Cotter, Philip D

    2012-07-01

    Supernumerary marker chromosomes (SMC) are relatively common in prenatal diagnosis. As the clinical outcomes vary greatly, a better understanding of the karyotype-phenotype correlation for different SMCs will be important for genetic counseling. We present two cases of prenatally detected de novo, small SMCs. The markers were present in 80% of amniocyte colonies in Case 1 and 38% of the colonies in Case 2. The SMCs were determined to be derived from chromosome 6 during postnatal confirmation studies. Although the sizes and the chromosomal origin of the SMCs in these two cases appeared to be similar, the clinical outcomes varied. The clinical manifestations observed in Case 1 included small for gestational age, feeding difficulty at birth, hydronephrosis, deviated septum and dysmorphic features, while the phenotype is apparently normal in Case 2. Array comparative genomic hybridization (CGH) was performed and showed increase in dosage for approximately 26 Mb of genetic material from the proximal short and long arms of chromosome 6 in Case 1. Results of array CGH were uninformative in Case 2, either due to mosaicism or lack of detectable euchromatin. The difference in the clinical presentation in these two patients may have resulted from the difference in the actual gene contents of the marker chromosomes and/or the differential distribution of the mosaicism.

  17. Characteristics and sequelae of erupted supernumerary teeth: A study of 218 cases among Sri Lankan children.

    Science.gov (United States)

    Herath, Chandra; Jayawardena, Chantha; Nagarathne, Nandani; Perera, Kanthi

    2016-12-19

    In the present study, we investigated the characteristics and sequelae of erupted supernumerary teeth (ST) in a sample of Sri Lankan children. Data were recorded from patients' clinical records, radiographs, models, and extracted teeth. The sample consisted of 239 ST from 218 patients. The mean age of the sample was 9.08 ± 2.47 years. The male-to-female ratio was 2.8:1. The majority (42.66%) of patients with ST were in aged 8-10 years. Many (94.94%) of the ST were located in the premaxilla (incisor), followed by the canine (4.22%), premolar (0.42%), and molar (0.42%) regions. The most common shape of ST teeth was conical. Malocclusion (59.83%) was the major problem associated with ST, and the clinical impact was highest on the 8-10-year age group. A strong association was observed between patients' age and clinical impact to the dentition (χ(2) =42.09, P=.000). Because the majority of ST can lead to malocclusion, especially in mixed dentition, awareness, early detection, and timely clinical intervention of ST are recommended. © 2016 John Wiley & Sons Australia, Ltd.

  18. Clinical management of a fused mandibular lateral incisor with supernumerary tooth: A case report

    Science.gov (United States)

    Aydemir, Seda; Ozel, Emre; Arukaslan, Goze; Tekce, Neslihan

    2016-01-01

    The purpose of this report is to present a rare case of a fused mandibular lateral incisor with supernumerary tooth with a follow-up for 18-months. A 35-year-old female patient was referred to our clinic with an extraoral sinus tract in the chin. The intraoral diagnosis revealed the fusion of her mandibular lateral incisors. Vitality pulp tests were negative for mandibular right central and lateral incisors. Radiographic examinations showed a fused tooth with two separate pulp chambers, two distinct roots, and two separate root canals. There were also periapical lesion of fused teeth and mandibular right central incisor, so endodontic treatment was carried out the related teeth. Radiographic examination revealed a complete healing of the lesion postoperatively at the end of 18-months. This paper reports the successful endodontic and restorative treatment of unilateral fused incisors. Because of the abnormal morphology of the crown and the complexity of the root canal system in fused teeth, treatment protocols require special attention. PMID:26962321

  19. Unexpected structural complexity of supernumerary marker chromosomes characterized by microarray comparative genomic hybridization

    Directory of Open Access Journals (Sweden)

    Hing Anne V

    2008-04-01

    Full Text Available Abstract Background Supernumerary marker chromosomes (SMCs are structurally abnormal extra chromosomes that cannot be unambiguously identified by conventional banding techniques. In the past, SMCs have been characterized using a variety of different molecular cytogenetic techniques. Although these techniques can sometimes identify the chromosome of origin of SMCs, they are cumbersome to perform and are not available in many clinical cytogenetic laboratories. Furthermore, they cannot precisely determine the region or breakpoints of the chromosome(s involved. In this study, we describe four patients who possess one or more SMCs (a total of eight SMCs in all four patients that were characterized by microarray comparative genomic hybridization (array CGH. Results In at least one SMC from all four patients, array CGH uncovered unexpected complexity, in the form of complex rearrangements, that could have gone undetected using other molecular cytogenetic techniques. Although array CGH accurately defined the chromosome content of all but two minute SMCs, fluorescence in situ hybridization was necessary to determine the structure of the markers. Conclusion The increasing use of array CGH in clinical cytogenetic laboratories will provide an efficient method for more comprehensive characterization of SMCs. Improved SMC characterization, facilitated by array CGH, will allow for more accurate SMC/phenotype correlation.

  20. Burnside Rings of Fusion Systems

    DEFF Research Database (Denmark)

    Reeh, Sune Precht

    of the characteristic idempotent of F { the unique idempotent in the p-local double Burnside ring of S satisfying properties of Linckelmann and Webb. We describe this idempotent both in terms of fixed points and as a linear combination of transitive bisets. Additionally, using fixed points we determine the map......In this thesis we study the interactions between saturated fusion systems and group actions of the underlying p-groups. For a saturated fusion system F on a finite p-group S we construct the Burnside ring of F in terms of the finite S-sets whose actions respect the structure of the fusion system......, and we produce a basis for the Burnside ring that shares properties with the transitive sets for a finite group. We construct a transfer map from the p-local Burnside ring of the underlying p-group S to the p-local Burnside ring of F. Using such transfer maps, we give a new explicit construction...

  1. Unique Path Partitions

    DEFF Research Database (Denmark)

    Bessenrodt, Christine; Olsson, Jørn Børling; Sellers, James A.

    2013-01-01

    We give a complete classification of the unique path partitions and study congruence properties of the function which enumerates such partitions.......We give a complete classification of the unique path partitions and study congruence properties of the function which enumerates such partitions....

  2. The pattern of a specimen of Pycnogonum litorale (Arthropoda, Pycnogonida) with a supernumerary leg can be explained with the "boundary model" of appendage formation

    Science.gov (United States)

    Scholtz, Gerhard; Brenneis, Georg

    2016-02-01

    A malformed adult female specimen of Pycnogonum litorale (Pycnogonida) with a supernumerary leg in the right body half is described concerning external and internal structures. The specimen was maintained in our laboratory culture after an injury in the right trunk region during a late postembryonic stage. The supernumerary leg is located between the second and third walking legs. The lateral processes connecting to these walking legs are fused to one large structure. Likewise, the coxae 1 of the second and third walking legs and of the supernumerary leg are fused to different degrees. The supernumerary leg is a complete walking leg with mirror image symmetry as evidenced by the position of joints and muscles. It is slightly smaller than the normal legs, but internally, it contains a branch of the ovary and a gut diverticulum as the other legs. The causes for this malformation pattern found in the Pycnogonum individual are reconstructed in the light of extirpation experiments in insects, which led to supernumerary mirror image legs, and the "boundary model" for appendage differentiation.

  3. Stirling engine piston ring

    Science.gov (United States)

    Howarth, Roy B.

    1983-01-01

    A piston ring design for a Stirling engine wherein the contact pressure between the piston and the cylinder is maintained at a uniform level, independent of engine conditions through a balancing of the pressure exerted upon the ring's surface and thereby allowing the contact pressure on the ring to be predetermined through the use of a preloaded expander ring.

  4. Birth Control Ring

    Science.gov (United States)

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Birth Control Ring KidsHealth > For Teens > Birth Control Ring A A A What's in this article? ... español Anillo vaginal anticonceptivo What Is It? The birth control ring is a soft, flexible, doughnut-shaped ring ...

  5. Actin Rings of Power.

    Science.gov (United States)

    Schwayer, Cornelia; Sikora, Mateusz; Slováková, Jana; Kardos, Roland; Heisenberg, Carl-Philipp

    2016-06-20

    Circular or ring-like actin structures play important roles in various developmental and physiological processes. Commonly, these rings are composed of actin filaments and myosin motors (actomyosin) that, upon activation, trigger ring constriction. Actomyosin ring constriction, in turn, has been implicated in key cellular processes ranging from cytokinesis to wound closure. Non-constricting actin ring-like structures also form at cell-cell contacts, where they exert a stabilizing function. Here, we review recent studies on the formation and function of actin ring-like structures in various morphogenetic processes, shedding light on how those different rings have been adapted to fulfill their specific roles.

  6. Alternative loop rings

    CERN Document Server

    Goodaire, EG; Polcino Milies, C

    1996-01-01

    For the past ten years, alternative loop rings have intrigued mathematicians from a wide cross-section of modern algebra. As a consequence, the theory of alternative loop rings has grown tremendously. One of the main developments is the complete characterization of loops which have an alternative but not associative, loop ring. Furthermore, there is a very close relationship between the algebraic structures of loop rings and of group rings over 2-groups. Another major topic of research is the study of the unit loop of the integral loop ring. Here the interaction between loop rings and group ri

  7. Cytogenetic and molecular analysis of a ring (21) in a patient with partial trisomy 21 and megakaryocytic leukemia

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, C.G.; Blouin, J.L.; Bull, M.J. [Indiana Univ. School of Medicine, Indianapolis, IN (United States)]|[Univ. of Geneva Medical School, Geneva (Switzerland)] [and others

    1995-07-17

    We describe a patient with an asymmetric double ring 21 in mosaic form, 45,XX,-21/46,X,-21,+r(21), who has limited manifestations of Down syndrome and who developed acute myelofibrosis and megakaryocytic leukemia (AMKL), FAB M7, a hematologic disorder particularly common in Down syndrome patients. In situ hybridization studies, gene dosage, and DNA polymorphism analysis showed that the ring chromosome carries a duplicated region which extends from D21S406 on the centromeric side and includes marker D21S3 on the telomeric side. FISH studies indicate two sizes of ring 21 in the patient. The origin of the supernumerary chromosome 21 in the proband was paternal; furthermore, the r(21) probably was formed postzygotically. Included in the duplicated segment are the candidate genes for leukemia AML-1, ETS, and ERG. The potential significance of disomic homozygosity of loci on 21q in M7 megakaryocytic leukemia is discussed. 35 refs., 6 figs., 6 tabs.

  8. An Archetype Semi-Ring Fabry-Perot (SRFP) Resonator

    Science.gov (United States)

    Taghavi-Larigani, Shervin; VanZyl, Jakob

    2009-01-01

    We introduce and demonstrate the generation of a novel resonator, termed Semi-Ring Fabry-Perot (SRFP), that exhibits unique features, such as, its use of one plane mirror, allowing the SRFP to be easily fabricated as a symmetrical device. In addition to its unique features, it exhibits advantages of ring and Fabry-Perot resonators: 1) compared to a ring resonator that only allows a transmitted intensity, the Semi-Ring Fabry-Perot (SRFP) supports standing waves, allowing both a reflected and transmitted intensity; 2) the reflected light spectrum of the SRFP resonator is much narrower than similar Fabry-Perot, implying higher finesse.

  9. Supernumerary breast. A case Presentation Mama supernumeraria. Presentación de un caso

    Directory of Open Access Journals (Sweden)

    Juan Miguel Guerra Cabrera

    2010-07-01

    Full Text Available Congenital malformations of the breast appear in 10 % of the population. The existence of mammary tissue at any line of the breast is classified according to Kajava’s categories into eight classes which differ one from the other in the presence or absence of the areola of the breast, nipple and glandular tissue. This report presents a case of a puerpera who had delivered her child seven days before her attendance to hospital. She presented with discharge from her both axillae. On physical examination, a supernumerary nipple with milky secretion out from it was found in her right axilla and secretion throughout the contralateral axilla through the skin pores, with absence of nipple and areola in that axillary region. The echographic study revealed the presence of bilateral ectopic mammary tissue. This case belongs to Kajava’s class IV classification in the left axilla and a variery of Type I in the right axilla. In facing a mammary malformation, a conservative attitude seems to be the most appropriate although esthetics requires surgery. To keep into account the presence of supernumerary breasts will be a need for the prevention of breast cancer. This case has been presented due to all these reasons and the unusual features of this case.Las malformaciones congénitas de la mama aparecen hasta en un 10 % de la población. La existencia de tejido mamario en algún punto de las líneas mamarias se clasifica, según Kajava, en 8 clases, que se diferencian por la presencia o no de areola mamaria, pezón y tejido glandular. Se presenta el caso de una paciente con secreción por ambas axilas en su séptimo día de puerperio. En la exploración se detectó un pezón supernumerario en axila derecha con secreción láctea a través de este y secreción a través de la axila contra lateral por los poros de la piel, con ausencia de pezón y de areola. El estudio ecográfico demostró la presencia de tejido mamario ectópico bilateral. Este caso pertenece

  10. Supernumerary registrar experience at the University of Cape Town, South Africa

    Directory of Open Access Journals (Sweden)

    S Peer

    2017-01-01

    Full Text Available Background. Despite supernumerary registrars (SNRs being hosted in South African (SA training programmes, there are no reports of their experience. Objectives. To evaluate the experience of SNRs at the University of Cape Town, SA, and the experience of SNRs from the perspective of SA registrars (SARs. Methods. SNRs and SARs completed an online survey in 2012. Results. Seventy-three registrars responded; 42 were SARs and 31 were SNRs. Of the SNRs 47.8% were self-funded, 17.4% were funded through private organisations, and 34.8% were funded by governments. Average annual income was ZAR102 349 (range ZAR680 - 460 000. Funding was considered insufficient by 61.0%. Eighty-seven percent intended to return to their home countries. Personal sacrifices were deemed worthwhile from academic (81.8% and social (54.5% perspectives, but not financially (33.3%. Only a small majority were satisfied with the orientation provided and with assimilation into their departments. Almost half experienced challenges relating to cultural and social integration. Almost all SARs supported having SNRs. SNRs reported xenophobia from patients (23.8% and colleagues (47.8%, and felt disadvantaged in terms of learning opportunities, academic support and on-call allocations. Conclusions. SNRs are fee-paying students and should enjoy academic and teaching support equal to that received by SARs. Both the university and the teaching hospitals must take steps to improve the integration of SNRs and ensure that they receive equal access to academic support and clinical teaching, and also need to take an interest in their financial wellbeing. Of particular concern are perceptions of xenophobia from SA medical colleagues.

  11. Small supernumerary marker chromosomes (sSMC in humans; are there B chromosomes hidden among them

    Directory of Open Access Journals (Sweden)

    Ogilvie Caroline

    2008-06-01

    Full Text Available Abstract Background Small supernumerary marker chromosomes (sSMC and B-chromosomes represent a heterogeneous collection of chromosomes added to the typical karyotype, and which are both small in size. They may consist of heterochromatic and/or euchromatic material. Also a predominance of maternal transmission was reported for both groups. Even though sSMC and B-chromosomes show some similarity it is still an open question if B-chromosomes are present among the heterogeneous group of sSMC. According to current theories, sSMC would need drive, drift or beneficial effects to increase in frequency in order to become B chromosome. However, up to now no B-chromosomes were described in human. Results Here we provide first evidence and discuss, that among sSMC B-chromosomes might be hidden. We present two potential candidates which may already be, or may in future evolve into B chromosomes in human: (i sSMC cases where the marker is stainable only by DNA derived from itself; and (ii acrocentric-derived inverted duplication sSMC without associated clinical phenotype. Here we report on the second sSMC stainable exclusively by its own DNA and show that for acrocentric derived sSMC 3.9× more are familial cases than reported for other sSMC. Conclusion The majority of sSMC are not to be considered as B-chromosomes. Nonetheless, a minority of sSMC show similarities to B-chromosomes. Further studies are necessary to come to final conclusions for that problem.

  12. Esthetic and endodontic management of fused maxillary lateral incisor and supernumerary teeth with all ceramic restoration after trauma

    Directory of Open Access Journals (Sweden)

    Kiranmeet Kaur Khurana

    2014-01-01

    Full Text Available Double or fusion of the teeth is a primary developmental anomaly union of two independently developing primary or permanent teeth. The tooth fusion may contribute to various significant problems such as crowding, caries and periodontal diseases. Fused teeth require an interdisciplinary approach combining the endodontic, esthetic and prosthetic treatments. All ceramic restoration meets the requirement of better appearance, biocompatibility and long life. By using restorative therapy esthetic and functional criteria were satisfied. Management of a case of fusion of a maxillary lateral incisor and a supernumerary tooth is presented.

  13. Supernumerary teeth and pseudarthrosis of the mandible in a young male from the mediaeval cemetery in Stenjevec

    Directory of Open Access Journals (Sweden)

    Željka Bedić

    2010-06-01

    Full Text Available Anthropological analysis of a young adult male from the mediaeval Stenjevec skeletal series revealed supernumerary teeth on both sides of the mandible, and an un-united subcondylar fracture of the mandible. The first condition is a developmental abnormality, while subcondylar fractures are one of the most frequent fractures of the mandible. Although, the osteological collection of the Department of Archaeology of the Croatian academy of Sciences and Arts consists of nearly 5,500 skeletons, this is the first documented case that exhibits these conditions in Croatian archaeological skeletal series.

  14. On JB-Rings

    Institute of Scientific and Technical Information of China (English)

    Huanyin CHEN

    2007-01-01

    A ring R is a QB-ring provided that aR + bR = R with a, b ∈ R implies that there exists a y ∈ R such that a+by ∈ R-1q. It is said that a ring R is a JB-ring provided that R/J(R) is a QB-ring, where J(R) is the Jacobson radical of R. In this paper, various necessary and sufficient conditions, under which a ring is a JB-ring, are established. It is proved that JB-rings can be characterized by pseudo-similarity. Furthermore, the author proves that R is a J B-ring iff so is R/J(R)2.

  15. Multiple Impacted Permanent and Supernumerary Teeth in the Anterior Mandible of Nonsyndromic Case: A Systematic Review and Multidisciplinary Approach to Management

    Directory of Open Access Journals (Sweden)

    Pushkar Gawande

    2015-01-01

    Full Text Available Multiple impacted permanent and supernumerary teeth have been associated with the syndromes and metabolic disorders. Approximately, 75% of all the supernumerary teeth are impacted and are asymptomatic. Consequently, most such teeth constitute casual findings in the context of routine X-ray studies. Lack of eruptive force and rotation of tooth buds may cause multiple impactions, and additional examinations may be necessary to exclude systemic and metabolic conditions. We present a rare nonsyndromic case with 11 multiple impacted teeth in the anterior mandible, with systematic literature review and multidisciplinary management.

  16. On semi ring bornologies

    Science.gov (United States)

    Imran, A. N.; Rakhimov, I. S.; Husain, Sh. K. Said

    2016-06-01

    Our main focus in this work is to introduce new structure bornological semi rings. This generalizes the theory of algebraic semi rings from the algebraic setting to the framework of bornological sets. We give basic properties for this new structure. As well as, We study the fundamental construction of bornological semi ring as product, inductive limits and projective limits and their extensions on bornological semi ring. Additionally, we introduce the category of bornological semi rings and study product and pullback (fiber product) in the category of bornological semi rings.

  17. Idiopathic Fenestrated Complex Syndactyly in a Unique Crisscross Fashion.

    Science.gov (United States)

    Williams, Benjamin R; Van Heest, Ann E

    2016-12-01

    This case presents surgical treatment of a unique form of syndactyly: an isolated fenestrated, complex, crisscross syndactyly of the right middle and ring fingers. A 2-year-old boy presented with the ring finger lying dorsal and the middle finger lying volar, with the middle phalanges syndactylized. A surgical release was performed with a subsequent z-plasty, 2 years later, for scar elongation. At the age of 4, he has essentially full function of his hand with minimal limitations. This case demonstrates that 2 digits that were syndactylized in a coronal plane (ring finger dorsal and middle finger volar) can be successfully surgically separated.

  18. An unusual double supernumerary maxillary mesiodens in a Middle Iron Age skeleton from South Uist, Western Isles, Scotland.

    Science.gov (United States)

    Ives, Rachel

    2014-06-01

    Bilaterally occurring and fully erupted mesiodens occur infrequently in the modern population and have been little documented from past populations. This research presents an unusual case of a double maxillary mesiodens in the permanent dentition occurring in skeletal remains dating to the Middle Iron Age (250-410 AD) from South Uist, Western Isles of Scotland. Osteological analysis of an adult male included the inventory of teeth present/absent and analysis of dental pathologies (caries, calculus, periodontal disease, ante-mortem tooth loss, periapical abscesses), developmental defects and orthodontic anomalies (enamel hypoplastic defects, malposition, rotation, crowding, agenesis and supernumerary teeth). An unusual expression of double, fully erupted, mesiodens in the anterior permanent maxillary dentition representing supernumerary central incisors exists. The complete eruption had contributed to anterior displacement of one central incisor alveolar socket similar to documented modern clinical cases. Shallow sockets also implied an associated stunted development of the original central maxillary incisor roots. Occlusal enamel wear indicated the mesiodens had been abraded during mastication. Current clinical data suggest there is a much higher tendency for single mesiodens to exist rather than double and examples often fail to fully erupt into the dentition. This relative rarity may account for the few previous reports of this dental anomaly from past human remains and especially of this date. The fully erupted double example from South Uist contributes to the known evidence for orthodontic anomalies in the past. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Unique Access to Learning

    Science.gov (United States)

    Goble, Don

    2009-01-01

    This article describes the many learning opportunities that broadcast technology students at Ladue Horton Watkins High School in St. Louis, Missouri, experience because of their unique access to technology and methods of learning. Through scaffolding, stepladder techniques, and trial by fire, students learn to produce multiple television programs,…

  20. Birth Control Ring

    Science.gov (United States)

    ... Right Sport for You Healthy School Lunch Planner Birth Control Ring KidsHealth > For Teens > Birth Control Ring Print A A A What's in ... español Anillo vaginal anticonceptivo What Is It? The birth control ring is a soft, flexible, doughnut-shaped ...

  1. On Weakly Semicommutative Rings*

    Institute of Scientific and Technical Information of China (English)

    CHEN WEI-XING; CUI SHU-YING

    2011-01-01

    A ring R is said to be weakly scmicommutative if for any a, b ∈ R,ab = 0 implies aRb C_ Nil(R), where Nil(R) is the set of all nilpotcnt elements in R.In this note, we clarify the relationship between weakly semicommutative rings and NI-rings by proving that the notion of a weakly semicommutative ring is a proper generalization of NI-rings. We say that a ring R is weakly 2-primal if the set of nilpotent elements in R coincides with its Levitzki radical, and prove that if R is a weakly 2-primal ring which satisfies oα-condition for an endomorphism α of R (that is, ab = 0 (←→) aα(b) = 0 where a, b ∈ R) then the skew polynomial ring R[π; αα]is a weakly 2-primal ring, and that if R is a ring and I is an ideal of R such that I and R/I are both weakly semicommutative then R is weakly semicommutative.Those extend the main results of Liang et al. 2007 (Taiwanese J. Math., 11(5)(2007),1359-1368) considerably. Moreover, several new results about weakly semicommutative rings and NI-rings are included.

  2. Physics of quantum rings

    CERN Document Server

    Fomin, Vladimir M

    2013-01-01

    This book deals with a new class of materials, quantum rings. Innovative recent advances in experimental and theoretical physics of quantum rings are based on the most advanced state-of-the-art fabrication and characterization techniques as well as theoretical methods. The experimental efforts allow to obtain a new class of semiconductor quantum rings formed by capping self-organized quantum dots grown by molecular beam epitaxy. Novel optical and magnetic properties of quantum rings are associated with non-trivial topologies at the nanoscale. An adequate characterization of quantum rings is po

  3. Envelopes of Commutative Rings

    Institute of Scientific and Technical Information of China (English)

    Rafael PARRA; Manuel SAOR(I)N

    2012-01-01

    Given a significative class F of commutative rings,we study the precise conditions under which a commutative ring R has an F-envelope.A full answer is obtained when.F is the class of fields,semisimple commutative rings or integral domains.When F is the class of Noetherian rings,we give a full answer when the Krull dimension of R is zero and when the envelope is required to be epimorphic.The general problem is reduced to identifying the class of non-Noetherian rings having a monomorphic Noetherian envelope,which we conjecture is the empty class.

  4. RING PROXY SIGNATURES

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Proxy signatures have been used to enable the transfer of digital signing power within some context and ring signatures can be used to provide the anonymity of a signer. By combining the functionalities of proxy signatures and ring signatures, this paper introduces a new concept, named ring proxy signature, which is a proxy signature generated by an anonymous member from a set of potential signers. The paper also constructs the first concrete ring proxy signature scheme based on the provably secure Schnorr's signatures and two ID-based ring proxy signature schemes. The security analysis is provided as well.

  5. Generalized Derivations with Nilpotent Values on Semiprime Rings

    Institute of Scientific and Technical Information of China (English)

    Feng WEI

    2004-01-01

    Let R be a semiprime ring, RF be its left Martindale quotient ring and I be an essential ideal of R. Then every generalized derivation u defined on I can be uniquely extended to a generalized derivation of RF. Furthermore, if there exists a fixed positive integer n such that μ(x)n = 0 for all x ∈ I, thenμ = 0.

  6. Dosage Effects of X and Y Chromosomes on Language and Social Functioning in Children with Supernumerary Sex Chromosome Aneuploidies: Implications for Idiopathic Language Impairment and Autism Spectrum Disorders

    Science.gov (United States)

    Lee, Nancy Raitano; Wallace, Gregory L.; Adeyemi, Elizabeth I.; Lopez, Katherine C.; Blumenthal, Jonathan D.; Clasen, Liv S.; Giedd, Jay N.

    2012-01-01

    Background: Supernumerary sex chromosome aneuploidies (X/Y-aneuploidies), the presence of extra X and/or Y chromosomes, are associated with heightened rates of language impairments and social difficulties. However, no single study has examined different language domains and social functioning in the same sample of children with tri-, tetra-, and…

  7. Efficient ring perception for the Chemistry Development Kit.

    Science.gov (United States)

    May, John W; Steinbeck, Christoph

    2014-01-30

    The Chemistry Development Kit (CDK) is an open source Java library for manipulating and processing chemical information. A key aspect in handling chemical structures is the determination of the chemical rings. The rings of a structure are used areas including descriptors, stereochemistry, similarity, screening and atom typing. The CDK includes multiple algorithms for determining the rings of a structure on demand. Non-unique descriptions of rings were often used due to the slower performance of the unique alternatives. Efficient algorithms for handling chemical ring perception have been implemented and optimised in the CDK. The algorithms provide much faster computation of new and existing types of rings. Several optimisation and implementation considerations are discussed which improve real case usage. The performance is measured on several publicly available data sets and in several cases the new implementations were found to be more than an order of magnitude faster. Algorithmic improvements allow handling of much larger datasets in reasonable time. Faster computation allows more appropriate rings to be utilised in procedures such as aromaticity. Several areas that require ring perception have also seen a noticeable improvement. The time taken to compute the unique rings is now comparable allowing a correct usage throughout the toolkit. All source code is open source and freely available.

  8. Saturn's largest ring.

    Science.gov (United States)

    Verbiscer, Anne J; Skrutskie, Michael F; Hamilton, Douglas P

    2009-10-22

    Most planetary rings in the Solar System lie within a few radii of their host body, because at these distances gravitational accelerations inhibit satellite formation. The best known exceptions are Jupiter's gossamer rings and Saturn's E ring, broad sheets of dust that extend outward until they fade from view at five to ten planetary radii. Source satellites continuously supply the dust, which is subsequently lost in collisions or by radial transport. Here we report that Saturn has an enormous ring associated with its outer moon Phoebe, extending from at least 128R(S) to 207R(S) (Saturn's radius R(S) is 60,330 km). The ring's vertical thickness of 40R(S) matches the range of vertical motion of Phoebe along its orbit. Dynamical considerations argue that these ring particles span the Saturnian system from the main rings to the edges of interplanetary space. The ring's normal optical depth of approximately 2 x 10(-8) is comparable to that of Jupiter's faintest gossamer ring, although its particle number density is several hundred times smaller. Repeated impacts on Phoebe, from both interplanetary and circumplanetary particle populations, probably keep the ring populated with material. Ring particles smaller than centimetres in size slowly migrate inward and many of them ultimately strike the dark leading face of Iapetus.

  9. The contraceptive vaginal ring.

    Science.gov (United States)

    Edwardson, Jill; Jamshidi, Roxanne

    2010-03-01

    The contraceptive vaginal ring offers effective contraception that is self-administered, requires less frequent dosing than many other forms of contraception, and provides low doses of hormones. NuvaRing (Organon, Oss, The Netherlands), the only contraceptive vaginal ring approved for use in the United States, contains etonogestrel and ethinyl estradiol. It is inserted into the vagina for 3 weeks, followed by a 1-week ring-free period, and works by inhibiting ovulation. Most women note a beneficial effect on bleeding profiles and are satisfied with NuvaRing. Commonly reported adverse events include vaginitis, leukorrhea, headaches, and device-related events such as discomfort. Serious adverse events are rare. In Chile and Peru, progesterone-only vaginal contraceptive rings are available for nursing women. Studies are ongoing examining new formulations of vaginal contraceptive rings.

  10. New Dust Belts of Uranus: One Ring, Two Ring, Red Ring, Blue Ring

    Energy Technology Data Exchange (ETDEWEB)

    de Pater, I; Hammel, H B; Gibbard, S G; Showalter, M R

    2006-02-02

    We compare near-infrared observations of the recently discovered outer rings of Uranus with HST results. We find that the inner ring, R/2003 U 2, is red, whereas the outer ring, R/2003 U 1, is very blue. Blue is an unusual color for rings; Saturn's enigmatic E ring is the only other known example. By analogy to the E ring, R/2003 U 1 is probably produced via impacts into the embedded moon Mab, which apparently orbits at a location where non-gravitational perturbations favor the survival and spreading of sub-micron sized dust. R/2003 U 2 more closely resembles Saturn's G ring.

  11. Certain near-rings are rings, II

    Directory of Open Access Journals (Sweden)

    Howard E. Bell

    1986-01-01

    Full Text Available We investigate distributively-generated near-rings R which satisfy one of the following conditions: (i for each x,y∈R, there exist positive integers m, n for which xy=ymxn; (ii for each x,y∈R, there exists a positive integer n such that xy=(yxn. Under appropriate additional hypotheses, we prove that R must be a commutative ring.

  12. On Exchange QB∞-Rings

    Institute of Scientific and Technical Information of China (English)

    Huanyin Chen

    2007-01-01

    In this paper, we introduce a new class of rings, the QB∞-rings. We investigate necessary and sufficient conditions under which an exchange ring is a QB∞-ring. The modules over an exchange QB∞-ring are studied. Also, we prove that every regular square matrix over an exchange QB∞-ring admits a diagonal reduction by pseudo-invertible matrices.

  13. Neutrosophic LA-Semigroup Rings

    Directory of Open Access Journals (Sweden)

    Mumtaz Ali

    2015-01-01

    Full Text Available Neutrosophic LA-semigroup is a midway structure between a neutrosophic groupoid and a commutative neutrosophic semigroup. Rings are the old concept in algebraic structures. We combine the neutrosophic LA-semigroup and ring together to form the notion of neutrosophic LA-semigroup ring. Neutrosophic LAsemigroup ring is defined analogously to neutrosophic group ring and neutrosophic semigroup ring.

  14. NASA's unique networking environment

    Science.gov (United States)

    Johnson, Marjory J.

    1988-01-01

    Networking is an infrastructure technology; it is a tool for NASA to support its space and aeronautics missions. Some of NASA's networking problems are shared by the commercial and/or military communities, and can be solved by working with these communities. However, some of NASA's networking problems are unique and will not be addressed by these other communities. Individual characteristics of NASA's space-mission networking enviroment are examined, the combination of all these characteristics that distinguish NASA's networking systems from either commercial or military systems is explained, and some research areas that are important for NASA to pursue are outlined.

  15. Familial ring (18) mosaicism in a 23-year-old young adult with 46,XY,r(18) (::p11→q21::)/46,XY karyotype, intellectual disability, motor retardation and single maxillary incisor and in his phenotypically normal mother, karyotype 47,XX,+r(18)(::p11→q21::)/46,XX.

    Science.gov (United States)

    Balci, Sevim; Tümer, Celal; Karaca, Ciğdem; Bartsch, Oliver

    2011-05-01

    We report on a 23-year-old man with craniofacial findings of the holoprosencephaly spectrum disorder (microcephaly, hypotelorism, depressed nasal bridge, single median maxillary central incisor), fusion of C2-C3 vertebrae, intellectual disability, and severe sleep apnea. Chromosome analysis of blood lymphocytes showed 75% ring (18) cells and 25% normal cells, karyotype mos 46,XY,r(18)(::p11→q21::)[75]/46,XY[25]. His mother was phenotypically normal except for a double ureter and bifid renal pelvis as in his son. She had a supernumerary ring (18) in 10% of blood lymphocytes, karyotype mos 47,XX,+r(18)(::p11→q21::)[10]/46,XX[90]. Familial ring (18) is a rare cytogenetic abnormality. This is the first report of a mother with a supernumerary ring (18) and a son with ring (18) mosaicism. Interestingly, the son showed a true mosaicism (mixoploidy) of ring (18) and normal cells. The mother's 46,XX cells could be easily explained by mitotic instability and ring loss during cell division. However, the coexistence of ring (18) and normal cells in the son is unusual. Possibly, during early postzygotic divisions of a 47,XY,+r(18) zygote, two (possibly subsequent) genetic events could have occurred, one when one normal chromosome 18 was lost (resulting in a cell line with ring 18), and one when the ring 18 was lost (resulting in a cell line without ring, "escape to normal"). Alternatively, the zygote of the son could have been 46,XY,r(18), and postzygotic loss of the ring 18 could have resulted in monosomy 18 cells followed by duplication of chromosome 18 in these cells (a rare mechanism for cell survival previously described as "compensatory" isodisomy). Copyright © 2011 Wiley-Liss, Inc.

  16. Gulf ring algae

    Science.gov (United States)

    Although they rank among the tiniest of the microspcopic phytoplankton, coccolithophore algae aid oceanographers studying the Gulf Stream rings and the ring boundaries. The algal group could help to identify more precisely the boundary of the warm rings of water that spin off from the Gulf Stream and become independent pools of warm water in the colder waters along the northeastern U.S. coast.Coccolithophore populations in the Gulf Stream rings intrigue oceanographers for two reasons: The phytoplankton are subjected to an environment that changes every few days, and population explosions within one coccolithophore species seem to be associated with changes in the characteristics of ocean water, said Pat Blackwelder, an associate professor at the Nova Oceanographic Center in Dania, Fla. She is one of many studying the physics, chemistry, and biology of warm core rings. A special oceanography session on these rings was held at the recent AGU Fall Meeting/ASLO Winter Meeting.

  17. Token Ring Project

    Directory of Open Access Journals (Sweden)

    Adela Ionescu

    2007-01-01

    Full Text Available Ring topology is a simple configuration used to connect processes that communicate among themselves. A number of network standards such as token ring, token bus, and FDDI are based on the ring connectivity. This article will develop an implementation of a ring of processes that communicate among themselves via pipe links. The processes are nodes in the ring. Each process reads from its standard input and writes in its standard output. N-1 process redirects the its standard output to a standard input of the process through a pipe. When the ring-structure is designed, the project can be extended to simulate networks or to implement algorithms for mutual exclusion

  18. Impacted lower third molar fused with a supernumerary tooth--diagnosis and treatment planning using cone-beam computed tomography.

    Science.gov (United States)

    Ferreira-Junior, Osny; de Avila, Luciana Dorigatti; Sampieri, Marcelo Bonifácio da Silva; Dias-Ribeiro, Eduardo; Chen, Wei-liang; Fan, Song

    2009-12-01

    This paper reported a case of fusion between an impacted third molar and a supernumerary tooth, in which a surgical intervention was carried out, with the objective of removing the dental elements. The panoramic radiography was complemented by the Donovan's radiographic technique; but because of the proximity of the dental element to the mandibular ramus, it was not possible to have a final fusion diagnosis. Hence, the Cone-Beam Computed Tomography-which provides precise three-dimensional information-was used to determinate the fusion diagnosis and also to help in the surgical planning. In this case report we observed that the periapical, occlusal and panoramic were not able to show details which could only be examined through the cone-beam computed tomography.

  19. Pure and complete trisomy 18p due to a supernumerary marker chromosome associated with moderate mental retardation.

    Science.gov (United States)

    Mabboux, P; Brisset, S; Aboura, A; Pineau, D; Koubi, V; Joannidis, S; Labrune, P; Tachdjian, G

    2007-04-01

    Trisomy for the short arm of chromosome 18 or trisomy 18p, is rarely described. We report on a 13-year-old boy with minor facial anomalies, mental retardation, bilateral cryptorchidism associated with a de novo supernumerary marker chromosome (SMC). Using fluorescence in situ hybridization and comparative genomic hybridization analyses, this SMC corresponded to the p arm of chromosome 18 associated with a centromere of either chromosome 13 or 21 and nucleolus organizing regions (NORs). We report here the first case of a pure and complete trisomy 18p due to a SMC. This report and review of literature confirm that the main phenotypic anomaly associated with trisomy 18p is moderate mental retardation.

  20. Revascularization of an impacted, immature dilacerated permanent maxillary central incisor associated with odontoma and a supernumerary tooth

    Directory of Open Access Journals (Sweden)

    Priya Subramaniam

    2013-01-01

    Full Text Available To intentionally replant an impacted immature permanent maxillary central incisor in the mixed dentition period followed by revascularization in order to achieve apical root closure. A 9-year-old boy presented with retained maxillary left primary incisors. Radiographic evaluation revealed the presence of a supernumerary tooth and an odontoma associated with an impacted permanent maxillary left central incisor, having root dilaceration. Treatment included surgical removal of mesiodens and odontoma. The impacted dilacerated permanent central incisor was removed and intentionally replanted, followed by revascularization of pulp. During the follow-up, root end closure with narrowing of canal space was observed, patient has been asymptomatic and the tooth remains vital. Revascularization of the immature reimplanted tooth showed continued root development and thickening of the lateral dentinal walls through deposition of new hard tissue and narrowing of the canal space.

  1. Dusty plasma (Yukawa) rings

    CERN Document Server

    Sheridan, T E

    2010-01-01

    One-dimensional and quasi-one-dimensional strongly-coupled dusty plasma rings have been created experimentally. Longitudinal (acoustic) and transverse (optical) dispersion relations for the 1-ring were measured and found to be in very good agreement with the theory for an unbounded straight chain of particles interacting through a Yukawa (i.e., screened Coulomb or Debye-H\\"uckel) potential. These rings provide a new system in which to study one-dimensional and quasi-one-dimensional physics.

  2. Token ring technology report

    CERN Document Server

    2013-01-01

    Please note this is a Short Discount publication. This report provides an overview of the IBM Token-Ring technology and products built by IBM and compatible vendors. It consists of two sections: 1. A summary of the design trade-offs for the IBM Token-Ring. 2. A summary of the products of the major token-ring compatible vendors broken down by adapters and components, wiring systems, testing, and new chip technology.

  3. On -Coherent Endomorphism Rings

    Indian Academy of Sciences (India)

    Li-Xin Mao

    2008-11-01

    A ring is called right -coherent if every principal right ideal is finitely presented. Let $M_R$ be a right -module. We study the -coherence of the endomorphism ring of $M_R$. It is shown that is a right -coherent ring if and only if every endomorphism of $M_R$ has a pseudokernel in add $M_R; S$ is a left -coherent ring if and only if every endomorphism of $M_R$ has a pseudocokernel in add $M_R$. Some applications are given.

  4. Physics of quantum rings

    Energy Technology Data Exchange (ETDEWEB)

    Fomin, Vladimir M. (ed.) [Leibniz Institute for Solid State and Materials Research, Dresden (Germany)

    2014-07-01

    Presents the new class of materials of quantum rings. Provides an elemental basis for low-cost high-performance devices promising for electronics, optoelectronics, spintronics and quantum information processing. Explains the physical properties of quantum rings to cover a gap in scientific literature. Presents the application of most advanced nanoengineering and nanocharacterization techniques. This book deals with a new class of materials, quantum rings. Innovative recent advances in experimental and theoretical physics of quantum rings are based on the most advanced state-of-the-art fabrication and characterization techniques as well as theoretical methods. The experimental efforts allow to obtain a new class of semiconductor quantum rings formed by capping self-organized quantum dots grown by molecular beam epitaxy. Novel optical and magnetic properties of quantum rings are associated with non-trivial topologies at the nanoscale. An adequate characterization of quantum rings is possible on the basis of modern characterization methods of nanostructures, such as Scanning Tunneling Microscopy. A high level of complexity is demonstrated to be needed for a dedicated theoretical model to adequately represent the specific features of quantum rings. The findings presented in this book contribute to develop low-cost high-performance electronic, spintronic, optoelectronic and information processing devices based on quantum rings.

  5. Collisional Features in Saturn's F Ring

    Science.gov (United States)

    Attree, Nicholas Oliver; Murray, Carl; Cooper, Nicholas; Williams, Gareth

    2016-10-01

    Saturn's highly dynamic F ring contains a population of small (radius ~ 1 km) moonlets embedded within its core or on nearby orbits. These objects interact, both gravitationally and collisionally, with the ring producing a range of features, some of which are unique to it. Here we present a brief overview of F ring collisional processes, investigated using a combination of Cassini imaging, simulations and orbital dynamics. Collisions produce linear debris clouds, known as 'jets' and 'mini-jets', which evolve, due to differential orbital motion, over periods ranging from hours to months. Mini-jet-forming collisions occur daily in the F ring whilst larger, more dramatic, events are rarer but produce jets that persist for many months, 'wrapping around' the ring to form almost parallel strands. Measuring jet properties, such as formation rates and relative orbits, allows us to infer a local population of order hundreds of objects colliding at relative velocities of a few metres per second. N-body modelling of the collisions shows good agreement with observations when two aggregates are allowed to impact and partially fragment (as opposed to a solid moonlet encountering dust), implying massive objects both in the core and nearby. Multiple, repeated collisions by the same, or fragments of the same, object are also important in explaining some jet morphology, showing that many objects survive the collisions. The F ring represents a natural laboratory for observing low-velocity collisions between icy objects as well as the ongoing aggregation and accretion that most-likely forms them.

  6. Ring Around a Galaxy

    Science.gov (United States)

    1999-01-01

    Space Telescope Science Institute astronomers are giving the public chances to decide where to aim NASA's Hubble Space Telescope. Guided by 8,000 Internet voters, Hubble has already been used to take a close-up, multi-color picture of the most popular object from a list of candidates, the extraordinary 'polar-ring' galaxy NGC 4650A. Located about 130 million light-years away, NGC 4650A is one of only 100 known polar-ring galaxies. Their unusual disk-ring structure is not yet understood fully. One possibility is that polar rings are the remnants of colossal collisions between two galaxies sometime in the distant past, probably at least 1 billion years ago. What is left of one galaxy has become the rotating inner disk of old red stars in the center. Meanwhile, another smaller galaxy which ventured too close was probably severely damaged or destroyed. The bright bluish clumps, which are especially prominent in the outer parts of the ring, are regions containing luminous young stars, examples of stellar rebirth from the remnants of an ancient galactic disaster. The polar ring appears to be highly distorted. No regular spiral pattern stands out in the main part of the ring, and the presence of young stars below the main ring on one side and above on the other shows that the ring is warped and does not lie in one plane. Determining the typical ages of the stars in the polar ring is an initial goal of our Polar Ring Science Team that can provide a clue to the evolution of this unusual galaxy. The HST exposures were acquired by the Hubble Heritage Team, consisting of Keith Noll, Howard Bond, Carol Christian, Jayanne English, Lisa Frattare, Forrest Hamilton, Anne Kinney and Zolt Levay, and guest collaborators Jay Gallagher (University of Wisconsin-Madison), Lynn Matthews (National Radio Astronomy Observatory-Charlottesville), and Linda Sparke (University of Wisconsin-Madison).

  7. Neptune's ring system.

    Science.gov (United States)

    Porco, C. C.; Nicholson, P. D.; Cuzzi, J. N.; Lissauer, J. J.; Esposito, L. W.

    The authors review the current state of knowledge regarding the structure, particle properties, kinematics, dynamics, origin, and evolution of the Neptune rings derived from Earth-based and Voyager data. Neptune has a diverse system of five continuous rings - 2 broad (Galle and Lassell) and 3 narrow (Adams, Le Verrier, and Arago) - plus a narrow discontinuous ring sharing the orbit of one of its ring-region satellites, Galatea. The outermost Adams ring contains the only arcs observed so far in Voyager images. The five arcs vary in angular extent from ≡1° to ≡10°, and exhibit internal azimuthal structure with typical spatial scales of ≡0.5°. All five lie within ≡40° of longitude. Dust is present throughout the Neptune system and measureable quantities of it were detected over Neptune's north pole. The Adams ring (including the arcs) and the Le Verrier ring contain a significant fraction of dust. The Neptune ring particles are probably red, and may consist of ice "dirtied" with silicates and/or some carbon-bearing material. A kinematic model for the arcs derived from Voyager data, the arcs' physical characteristics, and their orbital geometry and phasing are all roughly in accord with single-satellite arc shepherding by Galatea, though the presence of small kilometer-sized bodies embedded either within the arcs or placed at their Lagrange points may explain some inconsistencies with this model.

  8. Algorithms for finite rings

    NARCIS (Netherlands)

    Ciocanea Teodorescu I.,

    2016-01-01

    In this thesis we are interested in describing algorithms that answer questions arising in ring and module theory. Our focus is on deterministic polynomial-time algorithms and rings and modules that are finite. The first main result of this thesis is a solution to the module isomorphism problem in

  9. Revocable Ring Signature

    Institute of Scientific and Technical Information of China (English)

    Dennis Y. W. Liu; Joseph K. Liu; Yi Mu; Willy Susilo; Duncan S. Wong

    2007-01-01

    Group signature allows the anonymity of a real signer in a group to be revoked by a trusted party called group manager. It also gives the group manager the absolute power of controlling the formation of the group. Ring signature, on the other hand, does not allow anyone to revoke the signer anonymity, while allowing the real signer to forma group (also known as a ring) arbitrarily without being controlled by any other party. In this paper, we propose a new variant for ring signature, called Revocable Ring Signature. The signature allows a real signer to form a ring arbitrarily while allowing a set of authorities to revoke the anonymity of the real signer. This new variant inherits the desirable properties from both group signature and ring signature in such a way that the real signer will be responsible for what it has signed as the anonymity is revocable by authorities while the real signer still has the freedom on ring formation. We provide a formal security model for revocable ring signature and propose an efficient construction which is proven secure under our security model.

  10. Illustration of Saturn's Rings

    Science.gov (United States)

    2001-01-01

    This illustration shows a close-up of Saturn's rings. These rings are thought to have formed from material that was unable to form into a Moon because of tidal forces from Saturn, or from a Moon that was broken up by Saturn's tidal forces.

  11. The Fermilab recycler ring

    Energy Technology Data Exchange (ETDEWEB)

    Martin Hu

    2001-07-24

    The Fermilab Recycler is a permanent magnet storage ring for the accumulation of antiprotons from the Antiproton Source, and the recovery and cooling of the antiprotons remaining at the end of a Tevatron store. It is an integral part of the Fermilab III luminosity upgrade. The following paper describes the design features, operational and commissioning status of the Recycler Ring.

  12. EBT ring physics

    Energy Technology Data Exchange (ETDEWEB)

    Uckan, N.A. (ed.)

    1980-04-01

    This workshop attempted to evaluate the status of the current experimental and theoretical understanding of hot electron ring properties. The dominant physical processes that influence ring formation, scaling, and their optimal behavior are also studied. Separate abstracts were prepared for each of the 27 included papers. (MOW)

  13. Smoke Ring Physics

    Science.gov (United States)

    Huggins, Elisha

    2011-01-01

    The behavior of smoke rings, tornados, and quantized vortex rings in superfluid helium has many features in common. These features can be described by the same mathematics we use when introducing Ampere's law in an introductory physics course. We discuss these common features. (Contains 7 figures.)

  14. Algorithms for finite rings

    NARCIS (Netherlands)

    Ciocanea Teodorescu I.,

    2016-01-01

    In this thesis we are interested in describing algorithms that answer questions arising in ring and module theory. Our focus is on deterministic polynomial-time algorithms and rings and modules that are finite. The first main result of this thesis is a solution to the module isomorphism problem in

  15. Planetary rings - Theory

    Science.gov (United States)

    Borderies, Nicole

    1989-01-01

    Theoretical models of planetary-ring dynamics are examined in a brief analytical review. The mathematical description of streamlines and streamline interactions is outlined; the redistribution of angular momentum due to collisions between particles is explained; and problems in the modeling of broad, narrow, and arc rings are discussed.

  16. Steroidal contraceptive vaginal rings.

    Science.gov (United States)

    Sarkar, N N

    2003-06-01

    The development of steroid-releasing vaginal rings over the past three decades is reviewed to illustrate the role of this device as an effective hormonal contraceptive for women. Vaginal rings are made of polysiloxane rubber or ethylene-vinyl-acetate copolymer with an outer diameter of 54-60 mm and a cross-sectional diameter of 4-9.5 mm and contain progestogen only or a combination of progestogen and oestrogen. The soft flexible combined ring is inserted in the vagina for three weeks and removed for seven days to allow withdrawal bleeding. Progesterone/progestogen-only rings are kept in for varying periods and replaced without a ring-free period. Rings are in various stages of research and development but a few, such as NuvaRing, have reached the market in some countries. Women find this method easy to use, effective, well tolerated and acceptable with no serious side-effects. Though the contraceptive efficacy of these vaginal rings is high, acceptability is yet to be established.

  17. Jupiter's Rings: Sharpest View

    Science.gov (United States)

    2007-01-01

    The New Horizons spacecraft took the best images of Jupiter's charcoal-black rings as it approached and then looked back at Jupiter. The top image was taken on approach, showing three well-defined lanes of gravel- to boulder-sized material composing the bulk of the rings, as well as lesser amounts of material between the rings. New Horizons snapped the lower image after it had passed Jupiter on February 28, 2007, and looked back in a direction toward the sun. The image is sharply focused, though it appears fuzzy due to the cloud of dust-sized particles enveloping the rings. The dust is brightly illuminated in the same way the dust on a dirty windshield lights up when you drive toward a 'low' sun. The narrow rings are confined in their orbits by small 'shepherding' moons.

  18. The Enceladus Ring

    Science.gov (United States)

    2006-01-01

    [figure removed for brevity, see original site] The Enceladus Ring (labeled) This excellent view of the faint E ring -- a ring feature now known to be created by Enceladus -- also shows two of Saturn's small moons that orbit within the ring, among a field of stars in the background. The E ring extends from three to eight Saturn radii -- about 180,000 kilometers (118,000 miles) to 482,000 kilometers (300,000 miles). Its full extent is not visible in this view. Calypso (22 kilometers, or 14 miles across) and Helene (32 kilometers, or 20 miles across) orbit within the E ring's expanse. Helene skirts the outer parts of the E ring, but here it is projected in front of a region deeper within the ring. Calypso and Helene are trojan satellites, or moons that orbit 60 degrees in front or behind a larger moon. Calypso is a Tethys trojan and Helene is a trojan of Dione. An interesting feature of note in this image is the double-banded appearance of the E-ring, which is created because the ring is somewhat fainter in the ringplane than it is 500-1,000 kilometers (300-600 miles) above and below the ringplane. This appearance implies that the particles in this part of the ring have nonzero inclinations (a similar affect is seen in Jupiter's gossamer ring). An object with a nonzero inclination does not orbit exactly at Saturn's ringplane. Instead, its orbit takes it above and below the ringplane. Scientists are not entirely sure why the particles should have such inclinations, but they are fairly certain that the reason involves Enceladus. One possible explanation is that all the E ring particles come from the plume of icy material that is shooting due south out of the moon's pole. This means all of the particles are created with a certain velocity out of the ringplane, and then they orbit above and below that plane. Another possible explanation is that Enceladus produces particles with a range of speeds, but the moon gravitationally scatters any particles that lie very close to

  19. Molecular Scale Dynamics of Large Ring Polymers

    Science.gov (United States)

    Gooßen, S.; Brás, A. R.; Krutyeva, M.; Sharp, M.; Falus, P.; Feoktystov, A.; Gasser, U.; Pyckhout-Hintzen, W.; Wischnewski, A.; Richter, D.

    2014-10-01

    We present neutron scattering data on the structure and dynamics of melts from polyethylene oxide rings with molecular weights up to ten times the entanglement mass of the linear counterpart. The data reveal a very compact conformation displaying a structure approaching a mass fractal, as hypothesized by recent simulation work. The dynamics is characterized by a fast Rouse relaxation of subunits (loops) and a slower dynamics displaying a lattice animal-like loop displacement. The loop size is an intrinsic property of the ring architecture and is independent of molecular weight. This is the first experimental observation of the space-time evolution of segmental motion in ring polymers illustrating the dynamic consequences of their topology that is unique among all polymeric systems of any other known architecture.

  20. Earth: A Ringed Planet?

    Science.gov (United States)

    Hancock, L. O.; Povenmire, H.

    2010-12-01

    Among the most beautiful findings of the Space Age have been the discoveries of planetary rings. Not only Saturn but also Jupiter, Uranus and Neptune have rings; Saturn’s ring system has structures newly discovered; even Saturn's moon Rhea itself has a ring. All these are apparently supplied by material from the planetary moons (Rhea's ring by Rhea itself). The question naturally arises, why should the Earth not have a ring, and on the other hand, if it does, why has it not been observed? No rings have yet been observed in the inner solar system, but after all, rings in the inner solar system might simply tend to be fainter and more transient than those of the outer solar system: the inner solar system is more affected by the solar wind, and the Sun’s perturbing gravitational influence is greater. J.A. O’Keefe first suggested (1980) that Earth might have a ring system of its own. An Earth ring could account for some climate events. O’Keefe remarked that formation or thickening of a ring system in Earth’s equatorial plane could drive glaciation by deepening the chill of the winter hemisphere. (It is very well established that volcanic dust is an effective agent for the extinction of sunlight; this factor can be overwhelmingly apparent in eclipse observations.) O’Keefe died in 2000 and the speculation was not pursued, but the idea of an Earth ring has a prima facie reasonableness that calls for its renewed consideration. The program of this note is to hypothesize that, as O’Keefe proposed: (a) an Earth ring system exists; (b) it affects Earth's weather and climate; (c) the tektite strewn fields comprise filaments of the ring fallen to Earth's surface on various occasions of disturbance by comets or asteroids. On this basis, and drawing on the world's weather records, together with the Twentieth Century Reanalysis by NCEP/CIRES covering the period 1870-2010 and the geology of the tektite strewn fields, we herein propose the hypothesized Earth ring

  1. Local loop near-rings

    OpenAIRE

    Franetič, Damir

    2015-01-01

    We study loop near-rings, a generalization of near-rings, where the additive structure is not necessarily associative. We introduce local loop near-rings and prove a useful detection principle for localness.

  2. Management of Developing Anterior Malocclusion due to SupernumeraryTooth with Preventive and Intercep-tive Approach: A 1½ Year Case Study

    Science.gov (United States)

    Kambalimath, HV; Banda, Naveen Reddy

    2010-01-01

    ABSTRACT Variety of clinical complications occurs due to the presence of supernumerary teeth, especially mesiodens. It may result in impaction of one or both central incisors which in turn may lead to a variety of malocclusions. Timely intervention not only prevents malocclusion but also the time taken for corrective orthodontics. A complete case report of developing mesiodens’ tooth germ resulting in malocclusion including treatment in 1½ year period is presented. PMID:27507922

  3. Theodolite Ring Lights

    Science.gov (United States)

    Clark, David

    2006-01-01

    Theodolite ring lights have been invented to ease a difficulty encountered in the well-established optical-metrology practice of using highly reflective spherical tooling balls as position references. A theodolite ring light produces a more easily visible reflection and eliminates the need for an autocollimating device. A theodolite ring light is a very bright light source that is well centered on the optical axis of the instrument. It can be fabricated, easily and inexpensively, for use on a theodolite or telescope of any diameter.

  4. Heavy ion storage rings

    Energy Technology Data Exchange (ETDEWEB)

    Schuch, R.

    1987-01-01

    A brief overview of synchrotron storage rings for heavy ions, which are presently under construction in different accelerator laboratories is given. Ions ranging from protons up to uranium ions at MeV/nucleon energies will be injected into these rings using multiturn injection from the accelerators available or being built in these laboratories. After injection, it is planned to cool the phase space distribution of the ions by merging them with cold electron beams or laser beams, or by using stochastic cooling. Some atomic physics experiments planned for these rings are presented.

  5. Uniqueness is Important in Competition

    Institute of Scientific and Technical Information of China (English)

    FENG Ai-Xia; XV Xiu-Lian; HE Da-Ren

    2009-01-01

    We propose a quantitative network description on the function of uniqueness in a competition system. Two statistical parameters, competition ability and uniqueness are defined, and their relationship in ordinary cases is analytically discussed. The competition between Chinese regional universities is taken as an example. The empirical investigation results show that the uniqueness of a university is really important in competition. Also,uniqueness is very helpful in the promotion of the university overall quality.

  6. On Uniqueness of coalitional equilibria

    NARCIS (Netherlands)

    Finus, M.; Mouche, van P.H.M.; Rundshagen, B.

    2014-01-01

    For the so-called "new approach" of coalitio formation it is important that coalitional equilibria are unique. Uniqueness comes down to existene and to semi-uniqueness, i.e.\\\\that there exists at most one equilibrium. Although conditions for existence are not problematic, conditions for semi-uniquen

  7. 胎儿标记染色体及衍生染色体的细胞与分子遗传学研究%Cytogenetic and molecular genetic study of fetal supernumerary marker chromosomes and derivative chromosomes

    Institute of Scientific and Technical Information of China (English)

    林少宾; 史珊珊; 谢英俊; 陈争; 陈宝江; 吴坚柱; 方群

    2014-01-01

    Objective To investigate the prenatal diagnosis and phenotypic assessment strategies for fetal supernumerary marker chromosomes and derivative chromosomes. Methods Five cases of fetal supernumerary marker chromosomes and one case of fetal derivative chromosomes were diagnosed in the First Affiliated Hospital of Sun Yat-Sen University from March 12, 2010 to November 9, 2012 by conventional chromosome banding, fluorescence in situ hybridization (FISH) and spectral karyotyping (SKY). These cases were retrospectively reviewed. Combined with the results of ultrasonography, abnormal phenotypes and pregnancy outcomes were evaluated in these cases. Results All of the five supernumerary marker chromosomes were de novo, in which two were mosaic and the remaining three cases were non-mosaic. Of these five cases, two were type 47, XX+mar and ultrasound indicated abnormal phenotypes. FISH and SKY confirmed that they were derived from chromosome 4 and 22, respectively. The other three cases were marker chromosome with Turner syndrome karyotype (abnormal phenotypes were not found by ultrasound), in which two cases were derived from chromosome Y (by FISH) and one case was identified as ring chromosome X (by FISH and SKY). One de novo derivative chromosome was verified as a product of reciprocal translocation between chromosome 2 and 6 (by FISH and SKY). Induced abortion was performed in all cases between 25 and 32 gestational weeks. Conclusions By combining conventional chromosome banding, FISH and SKY, the origin and content of supernumerary marker chromosomes and derivative chromosomes can be identified. On this basis, clinical phenotype evaluation and genetic counseling may be offered with the ultrasonographic result.%目的:探讨胎儿标记染色体及衍生染色体的产前诊断与评估策略。方法通过传统染色体显带技术、荧光原位杂交(fluorescence in situ hybridization,FISH)及光谱核型分析(spectral karyotyping,SKY)等3种技

  8. Ringed Seal Distribution Map

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains GIS layers that depict the known spatial distributions (i.e., ranges) of the five subspecies of ringed seals (Phoca hispida). It was produced...

  9. The g-2 ring

    CERN Multimedia

    1974-01-01

    The precise measurement of "g-2", the anomalous magnetic moment of the muon, required a special muon storage ring with electrostatic focussing and very accurate knowledge of the magnetic bending field. For more details see under photo 7405430.

  10. Modified Newton's rings: II

    CERN Document Server

    Chaitanya, T Sai; Krishna, V Sai; Anandh, B Shankar; Umesh, K S

    2010-01-01

    In an earlier work (Shankar kumar Jha, A Vyas, O S K S Sastri, Rajkumar Jain & K S Umesh, 'Determination of wavelength of laser light using Modified Newton's rings setup', Physics Education, vol. 22, no.3, 195-202(2005)) reported by our group, a version of Newton's rings experiment called Modified Newton's rings was proposed. The present work is an extension of this work. Here, a general formula for wavelength has been derived, applicable for a plane of observation at any distance. A relation between the focal length and the radius curvature is also derived for a plano-convex lens which is essentially used as a concave mirror. Tracker, a video analysis software, freely downloadable from the net, is employed to analyze the fringes captured using a CCD camera. Two beams which give rise to interference fringes in conventional Newton's rings and in the present setup are clearly distinguished.

  11. Centralizer Near-rings, Matrix Near-rings and Cyclic p-Groups

    Institute of Scientific and Technical Information of China (English)

    Kirby C. Smith; Leon van Wyk

    2005-01-01

    If G is a finite group and A is a group of automorphisms of G, then it is known that the matrix near-ring Mm(MA(G); G) is a subnear-ring of the centralizer near ring MA(Gm) for every m ≥2. Conditions are known under which Mm(MA(G); G) is a proper subnear-ring of MA(Gm), and if .A and G are abelian, then conditions are known which imply the equality Mm(MA(G); G) = MA(Gm). In this paper, we characterize the groups 4 of automorphisms of a cyclic p-group G for which this equality holds. We also show that for every group A of automorphisms of a cyclic p-group G, either all the nonzero orbits of G are of unique type or none of the orbits of G is of unique type if p is odd, and there is a third possibility if p = 2, namely precisely one of the orbits of G is of unique type.

  12. Descent from the form ring and Buchsbaum rings

    CERN Document Server

    Schenzel, P

    1996-01-01

    There is a spectral sequence technique in order to estimate the local cohomology of a ring by the local cohomology of a certain form ring. As applications there are information on the descent of homological properties (Cohen-Macaulay, Buchsbaum etc.) from the form ring to the ring itself. In the case of Buchsbaum ring there is a discussion of the descent of the surjectivity of a natural map into the local cohomology.

  13. In search for significant cognitive features in Klinefelter syndrome through cross-species comparison of a supernumerary X chromosome.

    Science.gov (United States)

    Bruining, H; Swaab, H; de Sonneville, L M J; van Rijn, S; van Engeland, H; Kas, M J H

    2011-08-01

    The behavioral characterization of animals that carry genetic disorder abnormalities in a controlled genetic and environmental background may be used to identify human deficits that are significant to understand underlying neurobiological mechanisms. Here, we studied whether previously reported object recognition impairments in mice with a supernumerary X chromosome relate to specific cognitive deficits in Klinefelter syndrome (47,XXY). We aimed to optimize face validity by studying temporal object recognition in human cognitive assays. Thirty-four boys with Klinefelter syndrome (mean age 12.01) were compared with 90 age-matched normal controls, on a broad range of visual object memory tasks, including tests for pattern and temporal order discrimination. The results indicate that subjects with Klinefelter syndrome have difficulty in the processing of visual object and pattern information. Visual object patterns seem difficult to discriminate especially when temporal information needs to be processed and reproduced. On the basis of cross-species comparison, we propose that impaired temporal processing of object pattern information is an important deficit in Klinefelter syndrome. The current study shows how cross-species behavioral characterization may be used as a starting point to understand the neurobiology of syndromal phenotypic expression. The features of this study may serve as markers for interventions in Klinefelter syndrome. Similar cross-species evaluations of standard mouse behavioral paradigms in different genetic contexts may be powerful tools to optimize genotype-phenotype relationships.

  14. Unusually rapid growth of brown tumour in the mandible after parathyroidectomy associated with the presence of a supernumerary parathyroid gland.

    Science.gov (United States)

    Dorigatti de Ávila, Érica; de Molon, Rafael Scaf; Cabrini Gabrielli, Marisa Aparecida; Hochuli-Vieira, Eduardo; Sgavioli Massucato, Elaine Maria; de Mello-Filho, Francisco Veríssimo; Conti, Luis Carlos; Real Gabrielli, Mário Francisco

    2012-01-01

    The aim of this study is to report the case of a quick growing brown tumour in the jaw after a parathyroidectomy due to the presence of a rare fifth parathyroid gland. The patient had chronic renal disease and the diagnosis was tertiary hyperparathyroidism. Thirty days after the parathyroidectomy, the patient returned with a significant increase in the tumour size. The suspicion of a supernumerary gland was confirmed by parathyroid scintigraphy. The treatment of brown tumour is dependent on the treatment of the hyperparathyroidism. However, curettage should be considered if a large lesion is disturbing mastication. In conclusion, this case should attract the attention of general practitioner dentists, since they may be the first professionals who have contact with the patient with a brown tumour in the jaws. Likewise, this case emphasises the importance of knowing the type of hyperparathyroidism involved to allow for effective treatment planning. Copyright © 2011 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  15. Interactions between BMP-7 and USAG-1 (uterine sensitization-associated gene-1 regulate supernumerary organ formations.

    Directory of Open Access Journals (Sweden)

    Honoka Kiso

    Full Text Available Bone morphogenetic proteins (BMPs are highly conserved signaling molecules that are part of the transforming growth factor (TGF-beta superfamily, and function in the patterning and morphogenesis of many organs including development of the dentition. The functions of the BMPs are controlled by certain classes of molecules that are recognized as BMP antagonists that inhibit BMP binding to their cognate receptors. In this study we tested the hypothesis that USAG-1 (uterine sensitization-associated gene-1 suppresses deciduous incisors by inhibition of BMP-7 function. We learned that USAG-1 and BMP-7 were expressed within odontogenic epithelium as well as mesenchyme during the late bud and early cap stages of tooth development. USAG-1 is a BMP antagonist, and also modulates Wnt signaling. USAG-1 abrogation rescued apoptotic elimination of odontogenic mesenchymal cells. BMP signaling in the rudimentary maxillary incisor, assessed by expressions of Msx1 and Dlx2 and the phosphorylation of Smad protein, was significantly enhanced. Using explant culture and subsequent subrenal capsule transplantation of E15 USAG-1 mutant maxillary incisor tooth primordia supplemented with BMP-7 demonstrated in USAG-1+/- as well as USAG-1-/- rescue and supernumerary tooth development. Based upon these results, we conclude that USAG-1 functions as an antagonist of BMP-7 in this model system. These results further suggest that the phenotypes of USAG-1 and BMP-7 mutant mice reported provide opportunities for regenerative medicine and dentistry.

  16. B chromosome dynamics in Prochilodus costatus (Teleostei, Characiformes) and comparisons with supernumerary chromosome system in other Prochilodus species

    Science.gov (United States)

    Melo, Silvana; Utsunomia, Ricardo; Penitente, Manolo; Sobrinho-Scudeler, Patrícia Elda; Porto-Foresti, Fábio; Oliveira, Claudio; Foresti, Fausto; Dergam, Jorge Abdala

    2017-01-01

    Abstract Within the genus Prochilodus Agassiz, 1829, five species are known to carry B chromosomes, i.e. chromosomes beyond the usual diploid number that have been traditionally considered as accessory for the genome. Chromosome microdissection and mapping of repetitive DNA sequences are effective tools to assess the DNA content and allow a better understanding about the origin and composition of these elements in an array of species. In this study, a novel characterization of B chromosomes in Prochilodus costatus Valenciennes, 1850 (2n=54) was reported for the first time and their sequence complementarity with the supernumerary chromosomes observed in Prochilodus lineatus (Valenciennes, 1836) and Prochilodus argenteus Agassiz, 1829 was investigated. The hybridization patterns obtained with chromosome painting using the micro B probe of P. costatus and the satDNA SATH1 mapping made it possible to assume homology of sequences between the B chromosomes of these congeneric species. Our results suggest that the origin of B chromosomes in the genus Prochilodus is a phylogenetically old event. PMID:28919971

  17. Small supernumerary marker chromosomes derived from chromosomes 6 and 20 in a woman with recurrent spontaneous abortions.

    Science.gov (United States)

    Guediche, Narjes; Tosca, Lucie; Nouchy, Marc; Lecerf, Laure; Cornet, Dominique; Brisset, Sophie; Goossens, Michel; Tachdjian, Gérard

    2012-12-01

    In this report, we describe a case of multiple small supernumerary marker chromosomes (sSMC) presenting with recurrent abortions. Peripheral blood lymphocytes of a young, healthy and non-consanguineous couple who asked for genetic evaluation after two spontaneous miscarriages were obtained for karyotypes. Lymphocytes of the woman were analyzed by FISH techniques and DNA was extracted and used for array CGH investigation. Karyotyping revealed 48,XX,+2mar[24]/47,XX,+mar[5]/46,XX[3] for the woman and 46,XY for her husband. FISH analysis showed that the two sSMC consisted of chromosomes 6 and 20. Array CGH analysis showed gains of the 6p11.2q12 (9 Mb) and 20 p11.21 (3.3 Mb) chromosomal regions with a total of 42 genes present on both sSMC. Our findings support also the hypothesis that the modification of the expression of some genes involved in embryo implantation, like THBD gene, could be responsible in the recurrent abortions. This report underpins the necessity of array CGH for characterizing precisely sSMC and helping in genotype-phenotype correlations. Furthermore, a literature review on sSMC is included.

  18. Atypical supernumerary phantom limb and phantom limb pain in a patient with spinal cord injury: case report.

    Science.gov (United States)

    Choi, Ja Young; Kim, Hyo In; Lee, Kil Chan; Han, Zee-A

    2013-12-01

    Supernumerary phantom limb (SPL) resulting from spinal cord lesions are very rare, with only sporadic and brief descriptions in the literature. Furthermore, the reported cases of SPL typically occurred in neurologically incomplete spinal cord patients. Here, we report a rare case of SPL with phantom limb pain that occurred after traumatic spinal cord injury in a neurologically complete patient. After a traffic accident, a 43-year-old man suffered a complete spinal cord injury with a C6 neurologic level of injury. SPL and associated phantom limb pain occurred 6 days after trauma onset. The patient felt the presence of an additional pair of legs that originated at the hip joints and extended medially, at equal lengths to the paralyzed legs. The intensity of SPL and associated phantom limb pain subsequently decreased after visual-tactile stimulation treatment, in which the patient visually identified the paralyzed limbs and then gently tapped them with a wooden stick. This improvement continued over the 2 months of inpatient treatment at our hospital and the presence of the SPLs was reduced to 20% of the real paralyzed legs. This is the first comprehensive report on SPLs of the lower extremities after neurologically complete spinal cord injury.

  19. Multi-stage FE simulation of hot ring rolling

    Science.gov (United States)

    Wang, C.; Geijselaers, H. J. M.; van den Boogaard, A. H.

    2013-05-01

    As a unique and important member of the metal forming family, ring rolling provides a cost effective process route to manufacture seamless rings. Applications of ring rolling cover a wide range of products in aerospace, automotive and civil engineering industries [1]. Above the recrystallization temperature of the material, hot ring rolling begins with the upsetting of the billet cut from raw stock. Next a punch pierces the hot upset billet to form a hole through the billet. This billet, referred to as preform, is then rolled by the ring rolling mill. For an accurate simulation of hot ring rolling, it is crucial to include the deformations, stresses and strains from the upsetting and piercing process as initial conditions for the rolling stage. In this work, multi-stage FE simulations of hot ring rolling process were performed by mapping the local deformation state of the workpiece from one step to the next one. The simulations of upsetting and piercing stages were carried out by 2D axisymmetric models using adaptive remeshing and element erosion. The workpiece for the ring rolling stage was subsequently obtained after performing a 2D to 3D mapping. The commercial FE package LS-DYNA was used for the study and user defined subroutines were implemented to complete the control algorithm. The simulation results were analyzed and also compared with those from the single-stage FE model of hot ring rolling.

  20. Holomorphic Dynamics and Herman Rings

    DEFF Research Database (Denmark)

    Henriksen, Christian

    1997-01-01

    Existence theorem for Herman Rings of holomorphic mappings in a certain holomorphic family is given, using quasiconformal mappings. Proofs of topological properties of these Herman rings are given.......Existence theorem for Herman Rings of holomorphic mappings in a certain holomorphic family is given, using quasiconformal mappings. Proofs of topological properties of these Herman rings are given....

  1. Thermodynamic black di-rings

    CERN Document Server

    Iguchi, Hideo

    2010-01-01

    Previously the five dimensional $S^1$-rotating black rings have been superposed in concentric way by some solitonic methods and regular systems of two $S^1$-rotating black rings were constructed by the authors and then Evslin and Krishnan (we called these solutions black di-rings). In this place we show some characteristics of the solutions of five dimensional black di-rings, especially in thermodynamic equilibrium. After the summary of the di-ring expressions and their physical quantities, first we comment on the equivalence of the two different solution-sets of the black di-rings. Then the existence of thermodynamic black di-rings are shown, in which both iso-thermality and iso-rotation between the inner black ring and the outer black ring are realized. We also give detailed analysis of peculiar properties of the thermodynamic black di-ring including discussion about a certain kind of thermodynamic stability (instability) of the system.

  2. Ringed accretion disks: equilibrium configurations

    CERN Document Server

    Pugliese, D

    2015-01-01

    We investigate a model of ringed accretion disk, made up by several rings rotating around a supermassive Kerr black hole attractor. Each toroid of the ringed disk is governed by the General Relativity hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. Properties of the tori can be then determined by an appropriately defined effective potential reflecting the background Kerr geometry and the centrifugal effects. The ringed disks could be created in various regimes during the evolution of matter configurations around supermassive black holes. Therefore, both corotating and counterrotating rings have to be considered as being a constituent of the ringed disk. We provide constraints on the model parameters for the existence and stability of various ringed configurations and discuss occurrence of accretion onto the Kerr black hole and possible launching of jets from the ringed disk. We demonstrate that various ringed disks can be characterized by a maximum number of rings. We pr...

  3. Saturn's Other Ring Current

    Science.gov (United States)

    Crary, F. J.

    2014-04-01

    Saturn's main rings orbit the planet within an atmosphere and ionosphere of water, oxygen and hydrogen, produced by meteoritic impacts on and ultraviolet photodesorbtion of the ring particles [Johnson et al., 2006; Luhmann et al., 2006; Tseng et al., 2010]. The neutral atmosphere itself has only been tentatively detected through ultraviolet fluorescents of OH [Hall et al., 1996] while the ionosphere was observed in situ by the Cassini spacecraft shortly after orbital insertion [Coates et al.,2005; Tokar et al. 2005, Waite et al. 2005]. Although the plasma flow velocity of this ionosphere is not well-constrained, but the close association with the rings suggests that its speed would be couppled to the keplarian velocity of the rings themselves. As a result, the motion of the plasma through Saturn's magnetic field would produce an induced voltage, oriented away from the planet outside synchronous orbit and towards the planet inside synchronous orbit. Such a potential could result in currents flowing across the ring plane and closeing along magnetic field lines and through Saturn's ionosphere at latitudes between 36o and 48o. Cassini observations of whistler-mode plasma wave emissions [Xin et al.,2006] centered on synchronous orbit (1.76 Rs, mapping to 41o latitude) have been interpreted as a product of field-aligned electron beams associated with such a current. This presentation will investigate the magnitude of these currents and the resulting Joule heating of the ionosphere. An important constraint is that no auroral ultraviolet emissions have been observed at the relevant latitudes. In contrast, Joule heating could affect infrared emissions from H3+. Variations in H3+ emission associated with Saturn's rings have been reported by O'Donoghue et al., 2013, and interpreted as a result of ring "rain", i.e. precipitating water group species from the rings which alter ionosphereic chemistry and H3+ densities. As noted by O'Donoghue et al., this interpretation may be

  4. Design of a novel electrostatic ion storage ring at KACST

    Energy Technology Data Exchange (ETDEWEB)

    El Ghazaly, M.O.A., E-mail: maelghazaly@kacst.edu.sa [National Center for Mathematics and Physics (NCMP), King Abdulaziz City for Sciences and Technology (KACST), P.O. Box 6086, Riyadh 11442 (Saudi Arabia); Alshammari, S.M. [National Center for Mathematics and Physics (NCMP), King Abdulaziz City for Sciences and Technology (KACST), P.O. Box 6086, Riyadh 11442 (Saudi Arabia); Welsch, C.P. [Cockcroft Institute and the University of Liverpool (United Kingdom); Alharbi, H.H. [National Center for Mathematics and Physics (NCMP), King Abdulaziz City for Sciences and Technology (KACST), P.O. Box 6086, Riyadh 11442 (Saudi Arabia)

    2013-05-01

    A new electrostatic storage ring for beams at energies up to 30 keV·q is currently under development at the National Centre for Mathematics and Physics (NCMP), King Abdulaziz City for Science and Technology (KACST). The ring design is based on the existing electrostatic storage rings, but stretches significantly beyond them in that it shall form the core of a unique flexible experimental facility at KACST. The lattice of this ring has been designed in a way that enables the use of state-of-the-art experimental methods to study electron–ion, laser-ion, and ion-neutral beams interactions. The lattice design also allows for a future upgrade of the ring to a double storage ring structure that would enable ion–ion beam interactions to be performed. In this paper, we present the design of this ring with a focus on beam dynamics calculations for the 7° single-bend racetrack layout. The study is principally based on the SIMION8 program. We complemented this study further by using purpose-written routine and MAD-X simulation code. An in-depth investigation into beam stability under consideration of non-linear field components in the electrostatic optical elements, is presented. Finally, different working points and stability regions are discussed. -- Highlights: ► The design for a highly flexible electrostatic storage ring is carried out. ► It is shown this design can be upgraded to a double storage ring structure. ► SIMION can be used in ray-tracing simulations to compute aberrations in the ring. ► Non-linear effects in an electrostatic ring can potentially disturb the stored beam. ► An electrostatic ring can store low-energy beams in spite of existing fringe fields.

  5. Giant Rings in the Cosmic Microwave Background Sky

    Science.gov (United States)

    Kovetz, Ely D.; Ben-David, Assaf; Itzhaki, Nissan

    2010-11-01

    We find a unique direction in the cosmic microwave background sky around which giant rings have an anomalous mean temperature profile. This direction is in very close alignment with the afore measured anomalously large bulk flow direction. Using Monte Carlo simulations, we estimate the significance of the giant rings at the 3σ level and the alignment with the bulk flow at 2.5σ. We argue that a cosmic defect seeded by a pre-inflationary particle could explain the giant rings, the large bulk flow, and their alignment.

  6. 锥形束 CT在164例多生牙诊断中的应用研究%The application of CBCT in diagnosis of supernumerary teeth of 164 patients

    Institute of Scientific and Technical Information of China (English)

    戴昱; 黄盛兴; 陈圳华

    2015-01-01

    目的:探讨CBCT在多生牙的诊断和定位中的临床应用价值。方法以经CBCT发现的上下颌多生牙的164例患者的225颗多生牙为研究对象,分析多生牙的三维位置和类型。结果225颗多生牙全部显示,CBCT能清晰显示多生牙的数目、大小、位置、与邻近组织的关系。结论 CBCT能精确提示多生牙的影像信息,对多生牙的诊断及定位具有重要的指导意义。%Objective To evaluate the value of cone -beam CT ( CBCT) in the diagnosis and orientation of supernumerary teeth .Methods 225 supernumerary teeth of 164 patients examined by CBCT were included . The three-dimensional position and size were analyzed .Results 225 supernumerary teeth were totally clearly discovered, including the number, size, spatial location, and the relationship with the adjacent teeth and organizations .Conclusions Accurate three -dimensional information of supernumerary was provided by CBCT imaging, which is helpful for diagnosis and orientation of supernumerary teeth .

  7. An Optimal Algorithm for Conflict-Free Coloring for Tree of Rings

    CERN Document Server

    Pira, Einollah

    2012-01-01

    An optimal algorithm is presented about Conflict-Free Coloring for connected subgraphs of tree of rings. Suppose the number of the rings in the tree is |T| and the maximum length of rings is |R|. A presented algorithm in [1] for a Tree of rings used O(log|T|.log|R|) colors but this algorithm uses O(log|T|+log|R|) colors. The coloring earned by this algorithm has the unique-min property, that is, the unique color is also minimum.

  8. Oligomeric ferrocene rings

    Science.gov (United States)

    Inkpen, Michael S.; Scheerer, Stefan; Linseis, Michael; White, Andrew J. P.; Winter, Rainer F.; Albrecht, Tim; Long, Nicholas J.

    2016-09-01

    Cyclic oligomers comprising strongly interacting redox-active monomer units represent an unknown, yet highly desirable class of nanoscale materials. Here we describe the synthesis and properties of the first family of molecules belonging to this compound category—differently sized rings comprising only 1,1‧-disubstituted ferrocene units (cyclo[n], n = 5-7, 9). Due to the close proximity and connectivity of centres (covalent Cp-Cp linkages; Cp = cyclopentadienyl) solution voltammograms exhibit well-resolved, separated 1e- waves. Theoretical interrogations into correlations based on ring size and charge state are facilitated using values of the equilibrium potentials of these transitions, as well as their relative spacing. As the interaction free energies between the redox centres scale linearly with overall ring charge and in conjunction with fast intramolecular electron transfer (˜107 s-1), these molecules can be considered as uniformly charged nanorings (diameter ˜1-2 nm).

  9. Rings dominate western Gulf

    Science.gov (United States)

    Vidal L., Francisco V.; Vidal L., Victor M. V.; Molero, José María Pérez

    Surface and deep circulation of the central and western Gulf of Mexico is controlled by interactions of rings of water pinched from the gulf's Loop Current. The discovery was made by Mexican oceanographers who are preparing a full-color, 8-volume oceanographic atlas of the gulf.Anticyclonic warm-core rings pinch off the Loop Current at a rate of about one to two per year, the scientists of the Grupo de Estudios Oceanográficos of the Instituto de Investigaciones Eléctricas (GEO-IIE) found. The rings migrate west until they collide with the continental shelf break of the western gulf, almost always between 22° and 23°N latitude. On their westward travel they transfer angular momentum and vorticity to the surrounding water, generating cyclonic circulations and vortex pairs that completely dominate the entire surface and deep circulation of the central and western gulf.

  10. Autocatalytic chemical smoke rings

    CERN Document Server

    Rogers, M C; Rogers, Michael C.; Morris, Stephen W.

    2005-01-01

    Buoyant plumes, evolving free of boundary constraints, may develop well-defined mushroom shaped heads. In normal plumes, overturning flow in the head entrains less buoyant fluid from the surroundings as the head rises, robbing the plume of its driving force. We consider here a new type of plume in which the source of buoyancy is an autocatalytic chemical reaction. The reaction occurs at a sharp front which separates reactants from less dense products. In this type of plume, entrainment assists the reaction, producing new buoyancy which fuels an accelerating plume head. When the head has grown to a critical size, it detaches from the upwelling conduit, forming an accelerating, buoyant vortex ring. This vortex is analogous to a rising smoke ring. A second-generation head then develops at the point of detachment.Multiple generations of chemical vortex rings can detach from a single triggering event.

  11. Decay ring design

    CERN Document Server

    Chancé, A; Bouquerel, E; Hancock, S; Jensen, E

    The study of the neutrino oscillation between its different flavours needs pureand very intense fluxes of high energy, well collimated neutrinos with a welldetermined energy spectrum. A dedicated machine seems to be necessarynowadays to reach the required flux. A new concept based on the β-decayof radioactive ions which were accelerated in an accelerator chain was thenproposed. After ion production, stripping, bunching and acceleration, the unstableions are then stored in a racetrack-shaped superconducting decay ring.Finally, the ions are accumulated in the decay ring until being lost. The incomingbeam is merged to the stored beam by using a specific RF system, whichwill be presented here.We propose here to study some aspects of the decay ring, such as its opticalproperties, its RF system or the management of the losses which occur in thering (mainly by decay or by collimation).

  12. Almost ring theory

    CERN Document Server

    2003-01-01

    This book develops thorough and complete foundations for the method of almost etale extensions, which is at the basis of Faltings' approach to p-adic Hodge theory. The central notion is that of an "almost ring". Almost rings are the commutative unitary monoids in a tensor category obtained as a quotient V-Mod/S of the category V-Mod of modules over a fixed ring V; the subcategory S consists of all modules annihilated by a fixed ideal m of V, satisfying certain natural conditions. The reader is assumed to be familiar with general categorical notions, some basic commutative algebra and some advanced homological algebra (derived categories, simplicial methods). Apart from these general prerequisites, the text is as self-contained as possible. One novel feature of the book - compared with Faltings' earlier treatment - is the systematic exploitation of the cotangent complex, especially for the study of deformations of almost algebras.

  13. On Simple Noetherian Rings

    Institute of Scientific and Technical Information of China (English)

    Somyot Plubtieng

    2003-01-01

    A module M is called a CS-module (or extending module [5]) if every submodule of M is essential in a direct summand of M. It is shown that (i) a simple ring R is right noetherian if and only if every cyclic singular right R-module is either a CS-module or a noetherian module; (ii) for a prime ring R, if every proper cyclic right R-module is a direct sum of a quasi-injective module and a finitely cogenerated module, then R is either semisimple artinian or a right Ore domain; and (iii) a prime ring R is right noetherian if and only if every cyclic right R-module is a direct sum of a quasi-injective module and a noetherian module.

  14. Tunneling Through Black Rings

    Institute of Scientific and Technical Information of China (English)

    ZHAO Liu

    2007-01-01

    Hawking radiation of black ring solutions to 5-dimensional Einstein-Maxwell-dilaton theory is analyzed by use of the Parikh-Wilczek tunneling method. To get the correct tunneling amplitude and emission rate, we adopt and develop the Angheben-Nadalini-Vanzo-Zerbini covariant approach to cover the effects of rotation and electronic discharge all at once, and the effect of back reaction is also taken into account. This constitutes a unified approach to the tunneling problem. Provided the first law of thermodynamics for black rings holds, the emission rate is proportional to the exponential of the change of Bekenstein-Hawking entropy. Explicit calculation for black ring temperatures agrees exactly with the results obtained via the classical surface gravity method and the quasi-local formalism.

  15. Deployable Fresnel Rings

    Science.gov (United States)

    Kennedy, Timothy F.; Fink, Patrick W.; Chu, Andrew W.; Lin, Gregory Y.

    2014-01-01

    Deployable Fresnel rings (DFRs) significantly enhance the realizable gain of an antenna. This innovation is intended to be used in combination with another antenna element, as the DFR itself acts as a focusing or microwave lens element for a primary antenna. This method is completely passive, and is also completely wireless in that it requires neither a cable, nor a connector from the antenna port of the primary antenna to the DFR. The technology improves upon the previous NASA technology called a Tri-Sector Deployable Array Antenna in at least three critical aspects. In contrast to the previous technology, this innovation requires no connector, cable, or other physical interface to the primary communication radio or sensor device. The achievable improvement in terms of antenna gain is significantly higher than has been achieved with the previous technology. Also, where previous embodiments of the Tri-Sector antenna have been constructed with combinations of conventional (e.g., printed circuit board) and conductive fabric materials, this innovation is realized using only conductive and non-conductive fabric (i.e., "e-textile") materials, with the possible exception of a spring-like deployment ring. Conceptually, a DFR operates by canceling the out-of-phase radiation at a plane by insertion of a conducting ring or rings of a specific size and distance from the source antenna, defined by Fresnel zones. Design of DFRs follow similar procedures to those outlined for conventional Fresnel zone rings. Gain enhancement using a single ring is verified experimentally and through computational simulation. The experimental test setup involves a microstrip patch antenna that is directly behind a single-ring DFR and is radiating towards a second microstrip patch antenna. The first patch antenna and DFR are shown. At 2.42 GHz, the DFR improves the transmit antenna gain by 8.6 dB, as shown in Figure 2, relative to the wireless link without the DFR. A figure illustrates the

  16. Ring galaxies as the cradle for ULXs

    Science.gov (United States)

    Wolter, Anna

    2015-08-01

    Ring galaxies are unique laboratories where the effects of galaxy interactions can be studied and the final stages of stellar evolution investigated. They are characterized by high star formation rates (SFR) and low metallicity, which favours the formation of high mass remnants. The few ring galaxies for which high resolution X-ray data are available show enhanced X-ray emission, and large numbers of Ultraluminous X-ray sources (ULXs). Due to the peculiar morphology of ring galaxies, detected point sources in the ring are very likely to be physically associated with the galaxy, reducing the problem of contamination from spurious sources which affects other samples. However the evidence in the X-ray band is based on a very scanty sample of four galaxies.In order to find an unbiased sample with which to compare these findings, we have selected all the peculiar galaxies labelled as collisional rings with a spectroscopic redshift z<0.02 from the Arp & Madore `Catalogue of southern peculiar galaxies and associations'. This selection produces a sample of 12 galaxies which we have observed with Chandra and XMM-Newton. We will discuss the results of these observations and support for current models that propose low metallicity environments as the ideal cradle for ULXs. We will compare the results from this statistically selected sample with those from brighter and known ring galaxies in order to asses the likelihood to find IMBHs due to collision events. We will address the presence of other signs of interaction, from high SFR to multiwavelenght morphology and spectra (eg. IR, Halpha..).

  17. Saturn's rings - high resolution

    Science.gov (United States)

    1981-01-01

    Voyager 2 obtained this high-resolution picture of Saturn's rings Aug. 22, when the spacecraft was 4 million kilometers (2.5 million miles) away. Evident here are the numerous 'spoke' features, in the B-ring; their very sharp, narrow appearance suggests short formation times. Scientists think electromagnetic forces are responsible in some way for these features, but no detailed theory has been worked out. Pictures such as this and analyses of Voyager 2's spoke movies may reveal more clues about the origins of these complex structures. The Voyager project is managed for NASA by the Jet Propulsion Laboratory, Pasadena, Calif.

  18. Mechanisms of ring chromosome formation in 11 cases of human ring chromosome 21

    DEFF Research Database (Denmark)

    McGinniss, M J; Kazazian, H H; Stetten, G;

    1992-01-01

    We studied the mechanism of ring chromosome 21 (r(21)) formation in 13 patients (11 unique r(21)s), consisting of 7 from five families with familial r(21) and 6 with de novo r(21). The copy number of chromosome 21 sequences in the rings of these patients was determined by quantitative dosage......), resulting in deletion of varying amounts of 21q22.1 to 21qter. The data from one individual who had a Down syndrome phenotype were consistent with asymmetric breakage and reunion of 21q sequences from an intermediate isochromosome or Robertsonian translocation chromosome as reported by Wong et al. Another...... patient, who also exhibited Down syndrome, showed evidence of a third mechanism of ring formation. The likely initial event was breakage and reunion of the short and long arms, resulting in a small r(21), followed by a sister-chromatid exchange resulting in a double-sized and symmetrically dicentric r(21...

  19. Ring chromosome 13

    DEFF Research Database (Denmark)

    Brandt, C A; Hertz, Jens Michael; Petersen, M B;

    1992-01-01

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

  20. Planetary ring systems

    CERN Document Server

    Miner, Ellis D; Cuzzi, Jeffrey N

    2007-01-01

    This is the most comprehensive and up-to-date book on the topic of planetary rings systems yet written. The book is written in a style that is easily accessible to the interested non expert. Each chapter includes notes, references, figures and tables.

  1. On topologies over rings

    Directory of Open Access Journals (Sweden)

    Syed M. Fakhruddin

    1985-01-01

    Full Text Available In this note, we show that if a topology F¯ over a ring A satisfies a certain finiteness condition, then the Gabriel topology G¯ generated by F¯ can be explicitly constructed and it also satisfies the same finiteness condition.

  2. Fusion Rings for Quantum Groups

    DEFF Research Database (Denmark)

    2012-01-01

    We study the fusion rings of tilting modules for a quantum group at a root of unity modulo the tensor ideal of negligible tilting modules. We identify them in type A with the combinatorial rings from [12] and give a similar description of the sp2n-fusion ring in terms of noncommutative symmetric...... functions. Moreover we give a presentation of all fusion rings in classical types as quotients of polynomial rings. Finally we also compute the fu- sion rings for type G2....

  3. Fusion Rings for Quantum Groups

    DEFF Research Database (Denmark)

    Andersen, Henning Haahr; Stroppel, Catharina

    2012-01-01

    We study the fusion rings of tilting modules for a quantum group at a root of unity modulo the tensor ideal of negligible tilting modules. We identify them in type A with the combinatorial rings from [12] and give a similar description of the sp2n-fusion ring in terms of noncommutative symmetric...... functions. Moreover we give a presentation of all fusion rings in classical types as quotients of polynomial rings. Finally we also compute the fu- sion rings for type G2....

  4. Rings from Close Encounters

    Science.gov (United States)

    Kohler, Susanna

    2016-09-01

    Weve recently discovered narrow sets of rings around two minor planets orbiting in our solar system. How did these rings form? A new study shows that they could be a result of close encounters between the minor planets and giants like Jupiter or Neptune.Unexpected Ring SystemsPositions of the centaurs in our solar system (green). Giant planets (red), Jupiter trojans (grey), scattered disk objects (tan) and Kuiper belt objects (blue) are also shown. [WilyD]Centaurs are minor planets in our solar system that orbit between Jupiter and Neptune. These bodies of which there are roughly 44,000 with diameters larger than 1 km have dynamically unstable orbits that cross paths with those of one or more giant planets.Recent occultation observations of two centaurs, 10199 Chariklo and 2060 Chiron, revealed that these bodies both host narrow ring systems. Besides our four giant planets, Chariklo and Chiron are the only other bodies in the solar system known to have rings. But how did these rings form?Scientists have proposed several models, implicating collisions, disruption of a primordial satellite, or dusty outgassing. But a team of scientists led by Ryuki Hyodo (Paris Institute of Earth Physics, Kobe University) has recently proposed an alternative scenario: what if the rings were formed from partial disruption of the centaur itself, after it crossed just a little too close to a giant planet?Tidal Forces from a GiantHyodo and collaborators first used past studies of centaur orbits to estimate that roughly 10% of centaurs experience close encounters (passing within a distance of ~2x the planetary radius) with a giant planet during their million-year lifetime. The team then performed a series of simulations of close encounters between a giant planet and a differentiated centaur a body in which the rocky material has sunk to form a dense silicate core, surrounded by an icy mantle.Some snapshots of simulation outcomes (click for a closer look!) for different initial states of

  5. A small supernumerary marker chromosome present in a Turner syndrome patient not derived from X- or Y-chromosome: a case report

    OpenAIRE

    Vermeesch Joris; Andrieux Joris; Desai Manisha; Sheth Jayesh; Weise Anja; Kosyakova Nadezda; Ewers Elisabeth; Sheth Frenny; Hamid Ahmed B; Ziegler Monika; Liehr Thomas

    2009-01-01

    Abstract Background Small supernumerary marker chromosomes (sSMC) can be present in numerically abnormal karyotypes like in a 'Turner-syndrome karyotype' mos 45,X/46,X,+mar. Results Here we report the first case of an sSMC found in Turner syndrome karyotypes (sSMCT) derived from chromosome 14 in a Turner syndrome patient. According to cytogenetic and molecular cytogenetic characterization the karyotype was 46,X,+del(14)(q11.1). The present case is the third Turner syndrome case with an sSMCT ...

  6. The effect of virtual visual feedback on supernumerary phantom limb pain in a patient with high cervical cord injury: a single-case design study.

    Science.gov (United States)

    Katayama, Osamu; Iki, Hidemasa; Sawa, Shunji; Osumi, Michihiro; Morioka, Shu

    2015-01-01

    We characterized the effect of virtual visual feedback (VVF) on supernumerary phantom limb pain (SPLP) in a patient with high cervical cord injury. The subject was a 22-year-old man diagnosed with complete spinal cord injury (level C2) approximately 5 years ago. We applied the ABA'B' single-case design and set phases B and B' as intervention phases for comparison. SPLP significantly improved in comparison of phase A with phase B and phase A with phase B'. We suggest that VVF reduces SPLP and the effect lasts after VVF.

  7. Uniqueness property for quasiharmonic functions

    Directory of Open Access Journals (Sweden)

    Sevdiyor A. Imomkulov

    2014-10-01

    Full Text Available In this paper we consider a class of continuous functions, called quasiaharmonic functions, admitting best approximations by harmonic polynomials. In this class we prove a uniqueness theorem by analogy with the analytic functions.

  8. Diabetes: Unique to Older Adults

    Science.gov (United States)

    ... Stroke Urinary Incontinence Related Documents PDF Choosing Wisely: Diabetes Tests and Treatments Download Related Video Join our e-newsletter! Aging & Health A to Z Diabetes Unique to Older Adults This section provides information ...

  9. Osteoporosis: Unique to Older Adults

    Science.gov (United States)

    ... our e-newsletter! Aging & Health A to Z Osteoporosis Unique to Older Adults This section provides information ... and widely-prescribed medications for the treatment of osteoporosis. Some serious side effects of these medication have ...

  10. Nutrition: Unique to Older Adults

    Science.gov (United States)

    ... our e-newsletter! Aging & Health A to Z Nutrition Unique to Older Adults This section provides information ... teeth that are needed for grinding up food, nutrition suffers. If you are unable to chew and ...

  11. Ring autosomes: some unexpected findings.

    Science.gov (United States)

    Caba, L; Rusu, C; Plăiaşu; Gug, G; Grămescu, M; Bujoran, C; Ochiană, D; Voloşciuc, M; Popescu, R; Braha, E; Pânzaru, M; Butnariu, L; Sireteanu, A; Covic, M; Gorduza, Ev

    2012-12-01

    Ring chromosomes are rare entities, usually associated with phenotypic abnormalities in correlation with the loss of genetic material. There are various breakpoints and sometimes there is a dynamic mosaicism that is reflected in clinical features. Most of the ring chromosomes are de novo occurrences. Our study reflects the experience of three Romanian cytogenetic laboratories in the field of ring chromosomes. We present six cases with ring chromosomes involving chromosomes 5, 13, 18, and 21. All ring chromosomes were identified after birth in children with plurimalformative syndromes. The ring chromosome was present in mosaic form in three cases, and this feature reflects the ring's instability. In case of ring chromosome 5, we report a possible association with oculo-auriculo-vertebral spectrum.

  12. On Skew Triangular Matrix Rings

    Institute of Scientific and Technical Information of China (English)

    Wang Wei-liang; Wang Yao; Ren Yan-li

    2016-01-01

    Letαbe a nonzero endomorphism of a ring R, n be a positive integer and Tn(R,α) be the skew triangular matrix ring. We show that some properties related to nilpotent elements of R are inherited by Tn(R,α). Meanwhile, we determine the strongly prime radical, generalized prime radical and Behrens radical of the ring R[x;α]/(xn), where R[x;α] is the skew polynomial ring.

  13. e-læring

    DEFF Research Database (Denmark)

    Helms, Niels Henrik

    e-læring kan defineres på ganske mange måder. Ordet e-læring består jo tydeligt nok af to elementer. E + læring ligesom e-handel eller e-banking, og umiddelbart vil de fleste nok sige, at det så handler om læring vha. internettet. I bidraget advokeres for en læringsmæssig frem for normativ tilgang....

  14. The Black Ring is Unstable

    CERN Document Server

    Santos, Jorge E

    2015-01-01

    We study non-axisymmetric linearised gravitational perturbations of the Emparan-Reall black ring using numerical methods. We find an unstable mode whose onset lies within the "fat" branch of the black ring and continues into the "thin" branch. Together with previous results using Penrose inequalities that fat black rings are unstable, this provides numerical evidence that the entire black ring family is unstable.

  15. A Database of Invariant Rings

    OpenAIRE

    Kemper, Gregor; Körding, Elmar; Malle, Gunter; Matzat, B. Heinrich; Vogel, Denis; Wiese, Gabor

    2001-01-01

    We announce the creation of a database of invariant rings. This database contains a large number of invariant rings of finite groups, mostly in the modular case. It gives information on generators and structural properties of the invariant rings. The main purpose is to provide a tool for researchers in invariant theory.

  16. Integrated silicon optofluidic ring resonator

    NARCIS (Netherlands)

    Testa, G.; Huang, Y.; Sarro, P.M.; Zeni, L.; Bernini, R.

    2010-01-01

    The feasibility of an integrated silicon optofluidic ring resonator is demonstrated. Liquid core antiresonant reflecting optical waveguides are used to realize a rectangular ring resonator with a multimode interference liquid core coupler between the ring and the bus waveguide. In this configuration

  17. Non-Commutative Ring Theory

    CERN Document Server

    López-Permouth, Sergio

    1990-01-01

    The papers of this volume share as a common goal the structure and classi- fication of noncommutative rings and their modules, and deal with topics of current research including: localization, serial rings, perfect endomorphism rings, quantum groups, Morita contexts, generalizations of injectivitiy, and Cartan matrices.

  18. Ring closure in actin polymers

    Science.gov (United States)

    Sinha, Supurna; Chattopadhyay, Sebanti

    2017-03-01

    We present an analysis for the ring closure probability of semiflexible polymers within the pure bend Worm Like Chain (WLC) model. The ring closure probability predicted from our analysis can be tested against fluorescent actin cyclization experiments. We also discuss the effect of ring closure on bend angle fluctuations in actin polymers.

  19. RINGED ACCRETION DISKS: EQUILIBRIUM CONFIGURATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Pugliese, D.; Stuchlík, Z., E-mail: d.pugliese.physics@gmail.com, E-mail: zdenek.stuchlik@physics.cz [Institute of Physics and Research Centre of Theoretical Physics and Astrophysics, Faculty of Philosophy and Science, Silesian University in Opava, Bezručovo náměstí 13, CZ-74601 Opava (Czech Republic)

    2015-12-15

    We investigate a model of a ringed accretion disk, made up by several rings rotating around a supermassive Kerr black hole attractor. Each toroid of the ringed disk is governed by the general relativity hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. Properties of the tori can then be determined by an appropriately defined effective potential reflecting the background Kerr geometry and the centrifugal effects. The ringed disks could be created in various regimes during the evolution of matter configurations around supermassive black holes. Therefore, both corotating and counterrotating rings have to be considered as being a constituent of the ringed disk. We provide constraints on the model parameters for the existence and stability of various ringed configurations and discuss occurrence of accretion onto the Kerr black hole and possible launching of jets from the ringed disk. We demonstrate that various ringed disks can be characterized by a maximum number of rings. We present also a perturbation analysis based on evolution of the oscillating components of the ringed disk. The dynamics of the unstable phases of the ringed disk evolution seems to be promising in relation to high-energy phenomena demonstrated in active galactic nuclei.

  20. Saturn's ``Gossamer'' Ring: The F Ring's Inner Sheet

    Science.gov (United States)

    Showalter, M. R.; Burns, J. A.; Hamilton, D. P.

    1998-09-01

    Recent Galileo and Earth-based images have revealed for the first time that Jupiter's ``gossamer'' ring is actually composed of two rings, one bounded at the outer edge by Amalthea and the other bounded by Thebe. Dynamical models suggest that these rings are composed of dust grains ejected off the surfaces of the two moons, which then evolve inward under Poynting-Robertson drag. A very faint sheet of material filling the region between Saturn's A and F Rings reported by Burns et al. (BAAS 15, 1013--1014, 1983) may be a dynamically analogous system, in which dust escapes from the F Ring and evolves inward to the A Ring. Unlike Jupiter's gossamer rings, however, the inner sheet of Saturn's F Ring has been well observed from a large range of phase angles and visual wavelengths by Voyager. Voyager images reveal that this faint ring shows a tenfold increase in brightness between phase angles of 125(deg) and 165(deg) , indicating that it is composed of fine dust microns in size. Preliminary estimates of the normal optical depth fall in the range 1--2*E(-4) , depending on the dust size distribution assumed. Initial spectrophotometry reveals that the ring is neutral in color. The ring is uniform in brightness over the entire region between the two rings, with no evidence for internal structure associated with Prometheus and Atlas, suggesting that neither of these embedded moons acts as either a source or a sink. We will refine the aforementioned measurements and develop photometric models to better constrain the properties of the dust in this ring. This will enable us to relate the dust population to that in the F Ring proper, and to better explore the dynamical processes at work.

  1. Fine mapping of a supernumerary proleg mutant (E(Cs) -l) and comparative expression analysis of the abdominal-A gene in silkworm, Bombyx mori.

    Science.gov (United States)

    Chen, P; Tong, X-L; Li, D-D; Liang, P-F; Fu, M-Y; Li, C-F; Hu, H; Xiang, Z-H; Lu, C; Dai, F-Y

    2013-10-01

    Patterning and phenotypic variations of appendages in insects provide important clues on developmental genetics. In the silkworm Bombyx mori, morphological variations associated with the E complex, an analogue of the Drosophila melanogaster bithorax complex, mainly determine the shape and number of prolegs on abdominal segments. Here, we report the identification and characterization of the allele responsible for the supernumerary crescents and legs-like (E(Cs) -l) mutant, a model derived from spontaneous mutation of the E complex, with supernumerary legs and extra crescents. Fine mapping with 1605 individuals revealed a ∼68 kb sequence in the upstream intergenic region of B. mori abdominal-A (Bmabd-A) clustered with the E(Cs) -l locus. Quantitative real-time PCR (qRT-PCR) and Western blotting analyses disclosed a marked increase in Bmabd-A expression in the E(Cs) -l mutant at both the transcriptional and translational levels, compared to wild-type Dazao. Furthermore, we observed ectopic expression of the Bmabd-A protein in the second abdominal segment (A2) of the E(Cs) -l mutant. Our results collectively suggest that the 68 kb region contains important regulatory elements of the Bmabd-A gene, and provide evidence that the gene is required for limb development in abdominal segments in the silkworm.

  2. Combining VLBI and ring laser observations at normal equation level

    Science.gov (United States)

    Schartner, Matthias; Böhm, Johannes; Böhm, Sigrid; Schreiber, Karl Ulrich; Gebauer, André

    2017-04-01

    Observations from ring laser gyroscopes can be used to continuously monitor earth rotation with high resolution and without an external reference frame, which makes them unique in contrast to other techniques like VLBI or GNSS. A combination, however, of ring laser and VLBI data could potentially result in an improved accuracy of estimated earth rotation parameters. In this study, we use observations from the ring laser "G" (Grossring) located at Wettzell (Germany) and combine them with VLBI observations at the normal equation level. The Vienna VLBI and Satellite Software (VieVS) is used to set up the normal equations for each VLBI session as SINEX files. We present combined estimates for polar motion and length of day and assess the impact by the ring laser observations.

  3. Crystalline beams in dispersion-free storage rings

    Directory of Open Access Journals (Sweden)

    Masahiro Ikegami

    2006-12-01

    Full Text Available Generating a multidimensional crystalline beam in a storage ring has been known to be difficult without a special cooling force, i.e., tapered cooling, because of the momentum dispersion induced by bending magnets. It is, however, possible to eliminate the dispersion all around the ring by adding an electric dipole field in each magnetic bending region. A storage ring with such unique deflectors should enable us to reach multidimensional crystalline states with an ordinary untapered cooling force. In order to verify this expectation, molecular dynamics simulations are performed to study beam crystallization in several dispersion-free storage rings including the S-LSR at Kyoto University. The present results show that various crystalline states can be established without relying on the tapered force.

  4. Computational studies of carbodiimide rings.

    Science.gov (United States)

    Damrauer, Robert; Lin, Hai; Damrauer, Niels H

    2014-05-02

    Computational studies of alicyclic carbodiimides (RN═C═NR) (rings five through twelve) at the MP2/6-31G(d,p)//MP2/6-31G(d,p) level of theory were conducted to locate the transition states between carbodiimides isomers. Transition states for rings six through twelve were found. The RNCNR dihedral angle is ∼0° for even-numbered rings, but deviates from 0° for rings seven, nine, eleven, and twelve. The even- and odd-numbered ring transition states have different symmetry point groups. Cs transition states (even rings) have an imaginary frequency mode that transforms as the asymmetric irreducible representation of the group. C2 transition states (odd rings) have a corresponding mode that transforms as the totally symmetric representation. Intrinsic reaction coordinate analyses followed by energy minimization along the antisymmetric pathways led to enantiomeric pairs. The symmetric pathways give diastereomeric isomers. The five-membered ring carbodiimide is a stable structure, possibly isolable. A twelve-membered ring transition state was found only without applying symmetry constraints (C1). Molecular mechanics and molecular dynamics studies of the seven-, eight-, and nine-membered rings gave additional structures, which were then minimized using ab initio methods. No structures beyond those found from the IRC analyses described were found. The potential for optical resolution of the seven-membered ring is discussed.

  5. Cytogenetic and molecular analysis of a ring (21) in a patient with partial trisomy 21 and megakaryocytic leukemia

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, C.G.; Bull, M.; Breitfeld, P. [Indiana Univ., Indianapolis, IN (United States)] [and others

    1994-09-01

    We describe a patient with an asymmetrical double ring 21 in mosaic form, 45,XX, -21/46,XX, -21, +r(21) (q22.11{yields}p11.2::q11.1{yields}q22.3), who has limited manifestations of Down`s syndrome and who developed acute myelofibrosis and megakaryocytic leukemia (AMKL), M7, a hematologic disorder particularly common in Down`s syndrome patients. In situ hybridization studies (gene dosage and DNA polymorphism analysis) show that the ring chromosome carries a duplicated region which extends from D21S258 on the centromeric side and includes marker D21S1245 on the telomeric side, but does not include the region from PFKL and ITGB2 through the telomere. FISH studies indicate two sizes of ring 21 in the patient. The origin of the supernumerary chromosome 21 in the proband was paternal; furthermore, the r(21) was probably formed post-zygotically. Included in the duplicated segment are the candidate genes for leukemia AML-1, ETS2 and ERG. If disomic homozygosity is important in the development of AMKL in the proband, the gene responsible maps either between the centromere and D21S11 or between D21S1239 and D21S1245.

  6. Magnetic fields in ring galaxies

    CERN Document Server

    Moss, D; Silchenko, O; Sokoloff, D; Horellou, C; Beck, R

    2016-01-01

    Many galaxies contain magnetic fields supported by galactic dynamo action. However, nothing definitive is known about magnetic fields in ring galaxies. Here we investigate large-scale magnetic fields in a previously unexplored context, namely ring galaxies, and concentrate our efforts on the structures that appear most promising for galactic dynamo action, i.e. outer star-forming rings in visually unbarred galaxies. We use tested methods for modelling $\\alpha-\\Omega$ galactic dynamos, taking into account the available observational information concerning ionized interstellar matter in ring galaxies. Our main result is that dynamo drivers in ring galaxies are strong enough to excite large-scale magnetic fields in the ring galaxies studied. The variety of dynamo driven magnetic configurations in ring galaxies obtained in our modelling is much richer than that found in classical spiral galaxies. In particular, various long-lived transients are possible. An especially interesting case is that of NGC 4513 where th...

  7. A season in Saturn's rings: Cycling, recycling and ring history

    Science.gov (United States)

    Esposito, L. W.; Meinke, B. K.; Albers, N.; Sremcevic, M.

    2012-04-01

    Cassini experiments have watched Saturn's ring system evolve before our eyes. Images and occultations show changes and transient events. The rings are a dynamic and complex geophysical system, incompletely modeled as a single-phase fluid. Key Cassini observations: High resolution images show straw, propellers, embedded moonlets, and F ring objects. Multiple UVIS, RSS and VIMS occutlations indicate multimodal ringlet and edge structure, including free and forced modes along with stochastic perturbations that are most likely caused by nearby mass concentrations. Vertical excursions are evident at ring edges and in other perturbed regions. The rings are occasionally hit by meteorites that leave a signature that may last centuries; meteoritic dust pollutes the rings. Temperature, reflectance and transmission spectra are influenced by the dynamical state of the ring particles. Saturn's Equinox 2009: Oblique lighting exposed vertical structure and embedded objects. The rings were the coldest ever. Images inspired new occultation and spectral analysis that show abundant structure in the perturbed regions. The rings are more variable and complex than we had expected prior to this seasonal viewing geometry. Sub-kilometer structure in power spectral analysis: Wavelet analysis shows features in the strongest density waves and at the shepherded outer edge of the B ring. Edges are variable as shown by multiple occultations and occultations of double stars. F ring kittens: 25 features seen in the first 102 occultations show a weak correlation with Prometheus location. We interpret these features as temporary aggregations. Simulation results indicate that accretion must be enhanced to match the kittens' size distribution. Images show that Prometheus triggers the formation of transient objects. Propellers and ghosts: Occulations and images provide evidence for small moonlets in the A, B and C rings. These indicate accretion occurs inside the classical Roche limit. Implications

  8. Design of a novel electrostatic ion storage ring at KACST

    CERN Document Server

    Ghazaly, M O A El; Welsch, C P; Alharbi, H H

    2013-01-01

    A new electrostatic storage ring for beams at energies up to 30keV.q is currently under development at the National Centre for Mathematics and Physics (NCMP), King Abdulaziz City for Science and Technology (KACST). The ring design is based on the existing electrostatic storage rings, but stretches significantly beyond them in that it shall form the core of a unique flexible experimental facility at KACST. The lattice of this ring has been designed in a way that enables the use of state-of-the-art experimental methods to study electron-ion, laser-ion, and ion-neutral beams interactions. The lattice design also allows for a future upgrade of the ring to a double storage ring structure that would enable ion-ion beam interactions to be performed. In this paper, we present the design of this ring with a focus on beam dynamics calculations for the 7o single-bend racetrack layout. The study is principally based on the SIMION8 program. We complemented this study further by using purpose-written routine and MAD-X simu...

  9. New Views of Jupiter's Rings

    Science.gov (United States)

    Burns, J. A.

    1998-09-01

    Jupiter's rings are the archetype of ethereal planetary rings (very-low optical-depth bands containing micron-sized "dust"). As a result of much improved observations by Galileo (Ockert-Bell* -- most citations are et al. and Icarus in press* or this meeting) and Keck (de Pater*), we now understand the nature of such rings. The ring has three components: a 104 km-thick toroidal halo (1.4-1.7 RJ; normal optical depth t = 10-6), a thin main ring (1.7-1.8 RJ; t = 10-6), and a pair of exterior gossamer rings (1.8-3.5RJ; t = 10-7). The main ring has patchy ( 20-30 percent) brightness. The ring is reddish and its particles satisfy a -2.5 differential power-law size distribution. Because particle lifetimes are brief, the rings must be continually regenerated, by collisions into parent bodies, which may be unseen or may be the known small ring-moons (Thomas*, Simonelli). The gossamer ring seems to be collisional ejecta derived from the ring-moons Amalthea and Thebe, and evolving inward by Poynting-Robertson drag (Burns). The particles drift through many electromagnetic resonances, clustering around synchronous orbit, which produce jumps in the particles' inclinations (Hamilton). The main ring is probably debris from Adrastea and Metis, which orbit in the equatorial plane. The halo particles are driven vertically by electromagnetic forces, which may be resonant (Schaffer & Burns) or not (Horanyi & Cravens). When halo orbits become highly distorted, particles are lost into Jupiter. Similar faint rings may be attendant to all small, close-in satellites (Showalter).

  10. Rufus Choate: A Unique Orator.

    Science.gov (United States)

    Markham, Reed

    Rufus Choate, a Massachusetts lawyer and orator, has been described as a "unique and romantic phenomenon" in America's history. Born in 1799 in Essex, Massachusetts, Choate graduated from Dartmouth College and attended Harvard Law School. Choate's goal was to be the top in his profession. Daniel Webster was Choate's hero. Choate became well…

  11. Uniqueness of PL Minimal Surfaces

    Institute of Scientific and Technical Information of China (English)

    Yi NI

    2007-01-01

    Using a standard fact in hyperbolic geometry, we give a simple proof of the uniqueness of PL minimal surfaces, thus filling in a gap in the original proof of Jaco and Rubinstein. Moreover, in order to clarify some ambiguity, we sharpen the definition of PL minimal surfaces, and prove a technical lemma on the Plateau problem in the hyperbolic space.

  12. On the Nagumo uniqueness theorem

    OpenAIRE

    Octavian G. Mustafa; O'Regan, Donal

    2011-01-01

    By a convenient reparametrisation of the integral curves of a nonlinear ordinary differential equation (ODE), we are able to improve the conclusions of the recent contribution [A. Constantin, Proc. Japan Acad. {\\bf 86(A)} (2010), 41--44]. In this way, we establish a flexible uniqueness criterion for ODEs without Lipschitz-like nonlinearities.

  13. The Lasso Problem and Uniqueness

    CERN Document Server

    Tibshirani, Ryan J

    2012-01-01

    The lasso is a popular tool for sparse linear regression, especially for problems in which the number of variables p exceeds the number of observations n. But when p>n, the lasso criterion is not strictly convex, and hence it may not have a unique minimum. An important question is: when is the lasso solution well-defined (unique)? We review results from the literature, which show that if the predictor variables are drawn from a continuous probability distribution, then there is a unique lasso solution with probability one, regardless of the sizes of n and p. We also show that this result extends easily to $\\ell_1$ penalized minimization problems over a wide range of loss functions. A second important question is: how can we deal with the case of non-uniqueness in lasso solutions? In light of the aforementioned result, this case really only arises when some of the predictor variables are discrete, or when some post-processing has been performed on continuous predictor measurements. Though we certainly cannot c...

  14. Tree Rings: Timekeepers of the Past.

    Science.gov (United States)

    Phipps, R. L.; McGowan, J.

    One of a series of general interest publications on science issues, this booklet describes the uses of tree rings in historical and biological recordkeeping. Separate sections cover the following topics: dating of tree rings, dating with tree rings, tree ring formation, tree ring identification, sample collections, tree ring cross dating, tree…

  15. The Rings Characterized by Minimal Left Ideals

    Institute of Scientific and Technical Information of China (English)

    Jun Chao WEI

    2005-01-01

    We study these rings with every minimal left ideal being a projective, direct summand and a p-injective module, respectively. Some characterizations of these rings are given, and the relations among them are obtained. With these rings, we characterize semisimple rings. Finally, we introduce MC2 rings, and give some characterizations of MC2 rings.

  16. RING E3 ligases

    DEFF Research Database (Denmark)

    Cho, Seok Keun; Ryu, Moon Young; Kim, Jong Hum

    2017-01-01

    response pathways of plants through various molecular and genetic studies. In particular, it was recently discovered that ubiquitin proteasome system (UPS), a regulatory mechanism for protein turn over, is greatly involved in the stress responsive pathways. In the UPS, many E3 ligases play key roles...... in recognizing and tethering poly-ubiquitins on target proteins for subsequent degradation by the 26S proteasome. Here we discuss the roles of RING ligases that have been defined in related to abiotic stress responses in plants....

  17. Fusion Rings for Quantum Groups

    DEFF Research Database (Denmark)

    2014-01-01

    We study the fusion rings of tilting modules for a quantum group at a root of unity modulo the tensor ideal of negligible tilting modules. We identify them in type A with the combinatorial rings from Korff, C., Stroppel, C.: The sl(ˆn)k-WZNW fusion ring: a combinato-rial construction and a realis......We study the fusion rings of tilting modules for a quantum group at a root of unity modulo the tensor ideal of negligible tilting modules. We identify them in type A with the combinatorial rings from Korff, C., Stroppel, C.: The sl(ˆn)k-WZNW fusion ring: a combinato-rial construction...... and a realisation as quotient of quantum cohomology. Adv. Math. 225(1), 200–268, (2010) and give a similar description of the sp2n-fusion ring in terms of non-commutative symmetric functions. Moreover we give a presentation of all fusion rings in classical types as quotients of polynomial rings. Finally we also...... compute the fusion rings for type G2....

  18. Viscosity of ring polymer melts

    KAUST Repository

    Pasquino, Rossana

    2013-10-15

    We have measured the linear rheology of critically purified ring polyisoprenes, polystyrenes, and polyethyleneoxides of different molar masses. The ratio of the zero-shear viscosities of linear polymer melts η0,linear to their ring counterparts η0,ring at isofrictional conditions is discussed as a function of the number of entanglements Z. In the unentangled regime η0,linear/η 0,ring is virtually constant, consistent with the earlier data, atomistic simulations, and the theoretical expectation η0,linear/ η0,ring = 2. In the entanglement regime, the Z-dependence of ring viscosity is much weaker than that of linear polymers, in qualitative agreement with predictions from scaling theory and simulations. The power-law extracted from the available experimental data in the rather limited range 1 < Z < 20, η0,linear/η0,ring ∼ Z 1.2±0.3, is weaker than the scaling prediction (η0,linear/η0,ring ∼ Z 1.6±0.3) and the simulations (η0,linear/ η0,ring ∼ Z2.0±0.3). Nevertheless, the present collection of state-of-the-art experimental data unambiguously demonstrates that rings exhibit a universal trend clearly departing from that of their linear counterparts, and hence it represents a major step toward resolving a 30-year-old problem. © 2013 American Chemical Society.

  19. Buoyant Norbury's vortex rings

    Science.gov (United States)

    Blyth, Mark; Rodriguez-Rodriguez, Javier; Salman, Hayder

    2014-11-01

    Norbury's vortices are a one-parameter family of axisymmetric vortex rings that are exact solutions to the Euler equations. Due to their relative simplicity, they are extensively used to model the behavior of real vortex rings found in experiments and in Nature. In this work, we extend the original formulation of the problem to include buoyancy effects for the case where the fluid that lies within the vortex has a different density to that of the ambient. In this modified formulation, buoyancy effects enter the problem through the baroclinic term of the vorticity equation. This permits an efficient numerical solution of the governing equation of motion in terms of a vortex contour method that tracks the evolution of the boundary of the vortex. Finally, we compare our numerical results with the theoretical analysis of the short-time evolution of a buoyant vortex. Funded by the Spanish Ministry of Economy and Competitiveness through grant DPI2011-28356-C03-02 and by the London Mathematical Society.

  20. Parameterization of tree-ring growth in Siberia

    Science.gov (United States)

    Tychkov, Ivan; Popkova, Margarita; Shishov, Vladimir; Vaganov, Eugene

    2016-04-01

    No doubt, climate-tree growth relationship is an one of the useful and interesting subject of studying in dendrochronology. It provides an information of tree growth dependency on climatic environment, but also, gives information about growth conditions and whole tree-ring growth process for long-term periods. New parameterization approach of the Vaganov-Shashkin process-based model (VS-model) is developed to described critical process linking climate variables with tree-ring formation. The approach (co-called VS-Oscilloscope) is presented as a computer software with graphical interface. As most process-based tree-ring models, VS-model's initial purpose is to describe variability of tree-ring radial growth due to variability of climatic factors, but also to determinate principal factors limiting tree-ring growth. The principal factors affecting on the growth rate of cambial cells in the VS-model are temperature, day light and soil moisture. Detailed testing of VS-Oscilloscope was done for semi-arid area of southern Siberia (Khakassian region). Significant correlations between initial tree-ring chronologies and simulated tree-ring growth curves were obtained. Direct natural observations confirm obtained simulation results including unique growth characteristic for semi-arid habitats. New results concerning formation of wide and narrow rings under different climate conditions are considered. By itself the new parameterization approach (VS-oscilloscope) is an useful instrument for better understanding of various processes in tree-ring formation. The work was supported by the Russian Science Foundation (RSF # 14-14-00219).

  1. Uniqueness theorems in linear elasticity

    CERN Document Server

    Knops, Robin John

    1971-01-01

    The classical result for uniqueness in elasticity theory is due to Kirchhoff. It states that the standard mixed boundary value problem for a homogeneous isotropic linear elastic material in equilibrium and occupying a bounded three-dimensional region of space possesses at most one solution in the classical sense, provided the Lame and shear moduli, A and J1 respectively, obey the inequalities (3 A + 2 J1) > 0 and J1>O. In linear elastodynamics the analogous result, due to Neumann, is that the initial-mixed boundary value problem possesses at most one solution provided the elastic moduli satisfy the same set of inequalities as in Kirchhoffs theorem. Most standard textbooks on the linear theory of elasticity mention only these two classical criteria for uniqueness and neglect altogether the abundant literature which has appeared since the original publications of Kirchhoff. To remedy this deficiency it seems appropriate to attempt a coherent description ofthe various contributions made to the study of uniquenes...

  2. Ring current and radiation belts

    Science.gov (United States)

    Williams, D. J.

    1987-01-01

    Studies performed during 1983-1986 on the ring current, the injection boundary model, and the radiation belts are discussed. The results of these studies yielded the first observations on the composition and charge state of the ring current throughout the ring-current energy range, and strong observational support for an injection-boundary model accounting for the origins of radiation-belt particles, the ring current, and substorm particles observed at R less than about 7 earth radii. In addition, the results have demonstrated that the detection of energetic neutral atoms generated by charge-exchange interactions between the ring current and the hydrogen geocorona can provide global images of the earth's ring current and its spatial and temporal evolution.

  3. Magnetization of two coupled rings

    Energy Technology Data Exchange (ETDEWEB)

    Avishai, Y [Department of Physics and Ilse Katz Center for Nanotechnology, Ben Gurion University, Beer Sheva 84105 (Israel); Luck, J M [Institut de Physique Theorique, IPhT, CEA Saclay, and URA 2306, CNRS, 91191 Gif-sur-Yvette cedex (France)], E-mail: yshai@bgu.ac.il, E-mail: jean-marc.luck@cea.fr

    2009-05-01

    We investigate the persistent currents and magnetization of a mesoscopic system consisting of two clean metallic rings sharing a single contact point in a magnetic field. Many novel features with respect to the single-ring geometry are underlined, including the explicit dependence of wavefunctions on the Aharonov-Bohm fluxes, the complex pattern of two-fold and three-fold degeneracies, the key role of length and flux commensurability, and in the case of commensurate ring lengths the occurrence of idle levels which do not carry any current. Spin-orbit interactions, induced by the electric fields of charged wires threading the rings, give rise to a peculiar version of the Aharonov-Casher effect where, unlike for a single ring, spin is not conserved. Remarkably enough, this can only be realized when the Aharonov-Bohm fluxes in both rings are neither integer nor half-integer multiples of the flux quantum.

  4. Black di-ring and infinite nonuniqueness

    CERN Document Server

    Iguchi, H; Iguchi, Hideo; Mishima, Takashi

    2007-01-01

    We show that the $S^1$-rotating black rings can be superposed by the solution generating technique. We analyze the black di-ring solution for the simplest case of multiple rings. There exists an equilibrium black di-ring where the conical singularities are cured by the suitable choice of physical parameters. Also there are infinite numbers of black di-rings with the same mass and angular momentum. These di-rings can have two different continuous limits of single black rings. Therefore we can transform the fat black ring to the thin ring with the same mass and angular momentum by way of the di-ring solutions.

  5. Saturn's Rings and Associated Ring Plasma Cavity: Evidence for Slow Ring Erosion

    Science.gov (United States)

    Farrell, W. M.; Kurth, W. S.; Gurnett, D. A.; Persoon, A. M.; MacDowall, R. J.

    2017-01-01

    We re-examine the radio and plasma wave observations obtained during the Cassini Saturn orbit insertion period, as the spacecraft flew over the northern ring surface into a radial distance of 1.3 Rs (over the C-ring). Voyager era studies suggest the rings are a source of micro-meteoroid generated plasma and dust, with theorized peak impact-created plasma outflows over the densest portion of the rings (central B-ring). In sharp contrast, the Cassini Radio and Plasma Wave System (RPWS) observations identify the presence of a ring-plasma cavity located in the central portion of the B-ring, with little evidence of impact-related plasma. While previous Voyager era studies have predicted unstable ion orbits over the C- ring, leading to field-aligned plasma transport to Saturns ionosphere, the Cassini RPWS observations do not reveal evidence for such instability-created plasma fountains. Given the passive ring loss processes observed by Cassini, we find that the ring lifetimes should extend >10(exp 9) years, and that there is limited evidence for prompt destruction (loss in <100 Myrs).

  6. Uniqueness and Non-uniqueness in the Einstein Constraints

    CERN Document Server

    Pfeiffer, H P; Pfeiffer, Harald P.; York, James W.

    2005-01-01

    We examine numerically a sequence of free data for the conformal thin sandwich (CTS) equations representing non-linearly perturbed Minkowski spacetimes. We find only one solution for the standard (four) CTS equations; however, we find {\\em two} distinct solutions for the same free data when the lapse is determined by a fifth elliptic equation arising from specification of the time derivative of the mean curvature. For a given {\\em physical} (conformally scaled) amplitude of the perturbation, the solution for the physical data $g_{ij}, K_{ij}$ nevertheless appears to be unique.

  7. Ion Composition of the Thermal Plasma in the F-Ring Region of Saturn

    Science.gov (United States)

    Ip, W. H.; Tseng, W. L.; Hsu, J. K.; Wei, C. E.; Shen, C. H.

    2016-12-01

    In the final phase of the Cassini mission in 2016-2017, the spacecraft will first move to orbits with periapse outside the F-ring and then to orbits grazing the upper atmosphere of Saturn. These trajectories will provide the unique opportunity to sample the structures and composition of Saturn's ionosphere but also those of the main rings. From an assessment of the neutral gas and plasma environment of the rings, we investigate the formation of molecular ions and nano-grains in the areas to be probed by Cassini during its F-ring and Proximal orbits

  8. ring og refleksion

    DEFF Research Database (Denmark)

    Wahlgren, B.; Rattleff, Pernille; Høyrup, S.

    State of the art inden for forskning om læring på arbejdspladsen samt gennemgang af læringsteori og refleksionsbegrebet hos Dewey, Dreyfus, Schön, Argyris, Kolb, Jarvis, Mezirow og Brookfield. Afsluttes med diskussion af syntetiseret model for læring på arbejdspladsen.......State of the art inden for forskning om læring på arbejdspladsen samt gennemgang af læringsteori og refleksionsbegrebet hos Dewey, Dreyfus, Schön, Argyris, Kolb, Jarvis, Mezirow og Brookfield. Afsluttes med diskussion af syntetiseret model for læring på arbejdspladsen....

  9. Why Are Ring Galaxies Interesting?

    CERN Document Server

    Higdon, James L

    2010-01-01

    Compared with ordinary spirals, the ISM in ring galaxies experiences markedly different physical conditions and evolution. As a result, ring galaxies provide interesting perspectives on the triggering/quenching of large scale star formation and the destructive effects of massive stars on molecular cloud complexes. We use high resolution radio, sub-millimeter, infrared, and optical data to investigate the role of gravitational stability in star formation regulation, factors influencing the ISM's molecular fraction, and evidence of peculiar star formation laws and efficiencies in two highly evolved ring galaxies: Cartwheel and the Lindsay-Shapley ring.

  10. On Weakly P.P. Rings

    Institute of Scientific and Technical Information of China (English)

    Xiang Yue-ming; Ouyang Lun-qun; Wang Shu-gui

    2015-01-01

    We introduce, in this paper, the right weakly p.p. rings as the generaliza-tion of right p.p. rings. It is shown that many properties of the right p.p. rings can be extended onto the right weakly p.p. rings. Relative examples are constructed. As applications, we also characterize the regular rings and the semisimple rings in terms of the right weakly p.p. rings.

  11. SIGNET-RING MUCINOUS ADENOCARCINOMA OF THE PANCREAS

    Institute of Scientific and Technical Information of China (English)

    W.H.Chow; LouisT.C.Chow

    1994-01-01

    An 88-year-old man presented symptoms and signs of ascending cholangitis and died 20 days after the onset of illness.Postmortem examination revealed a mucinous tumor arising from the head of the pancreas,encasing the common bile duct and invading the liver with multiple hepatic metastasis.The tumor showed a unique and uniform histological appearance,consisting of signet-ring neoplastic cells floating in mucin pools.The rapid clinical course and widespread hepatic metastasis of this patient suggest that this pure,signet-ring variant of mucinous adenocarcinoma of the pancreas might have a poorer prognosis.

  12. The eRHIC Ring-Ring Collider Design

    CERN Document Server

    Wang, Fuhua; Beebe-Wang, Joanne; Deshpande, Abhay A; Farkhondeh, Manouchehr; Franklin, Wilbur; Graves, William; Litvinenko, Vladimir N; MacKay, William W; Milner, Richard; Montag, Christoph; Ozaki, Satoshi; Parker, Brett; Peggs, Steve; Ptitsyn, Vadim; Roser, Thomas; Tepikian, Steven; Trbojevic, Dejan; Tschalär, C; Wang, Dong; Zolfaghari, Abbasali; Zwart, Townsend; van der Laan, Jan

    2005-01-01

    The eRHIC ring-ring collider is the main design option of the future lepton-ion collider at Brookhaven National Laboratory. We report the revisions of the ring-ring collider design features to the baseline design presented in the eRHIC Zeroth Design Report (ZDR). These revisions have been made during the past year. They include changes of the interaction region which are required from the modifications in the design of the main detector. They also include changes in the lepton storage ring for high current operations as a result of better understandings of beam-beam interaction effects. The updated collider luminosity and beam parameters also take into account a more accurate picture of current and future operational aspects of RHIC.

  13. Lithium nephropathy: unique sonographic findings.

    Science.gov (United States)

    Di Salvo, Donald N; Park, Joseph; Laing, Faye C

    2012-04-01

    This case series describes a unique sonographic appearance consisting of numerous microcysts and punctate echogenic foci seen on renal sonograms of 10 adult patients receiving chronic lithium therapy. Clinically, chronic renal insufficiency was present in 6 and nephrogenic diabetes insipidus in 2. Sonography showed numerous microcysts and punctate echogenic foci. Computed tomography in 5 patients confirmed microcysts and microcalcifications, which were fewer in number than on sonography. Magnetic resonance imaging in 2 patients confirmed microcysts in each case. Renal biopsy in 1 patient showed chronic interstitial nephritis, microcysts, and tubular dilatation. The diagnosis of lithium nephropathy should be considered when sonography shows these findings.

  14. Mucormycosis in India: unique features.

    Science.gov (United States)

    Chakrabarti, Arunaloke; Singh, Rachna

    2014-12-01

    Mucormycosis remains a devastating invasive fungal infection, with high mortality rates even after active management. The disease is being reported at an alarming frequency over the past decades from India. Indian mucormycosis has certain unique features. Rhino-orbito-cerebral presentation associated with uncontrolled diabetes is the predominant characteristic. Isolated renal mucormycosis has emerged as a new clinical entity. Apophysomyces elegans and Rhizopus homothallicus are emerging species in this region and uncommon agents such as Mucor irregularis and Thamnostylum lucknowense are also being reported. This review focuses on these distinct features of mucormycosis observed in India.

  15. UNIQUE ORAL DRUG DELIVERY SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Raphael M. Ottenbrite; ZHAO Ruifeng; Sam Milstein

    1995-01-01

    An oral drug delivery system using proteinoid microspheres is discussed with respect to its unique dependence on pH. It has been found that certain drugs such as insulin and heparin can be encapsulated in proteinoid spheres at stomach pH's (1-3). These spheres also dissemble at intestinal pH's (6-7) releasing the drug for absorption. Using this technique low molecular weight heparin and human growth hormone have been orally delivered successfully to several animal species. Future work has been proposed to study the interaction and binding of the specific drugs with synthesized oligopeptides.

  16. Analysis of unique beta transitions

    DEFF Research Database (Denmark)

    Eman, B.; Krmpotic, F.; Tadic, D;

    1967-01-01

    The Heidelberg group measurements [For abstr. see Phys. Rev. Nucl. Sci. Vol. 15 (1965)] of unique forbidden transitions have been analysed. It has been found that experimental shape factors can be reproduced only with the induced pseudoscalar form factor d ...-non-conserving tensor form factor b > 0. In the former case they contradict Daniel's results [See abstr. 1966A10720] for 0- rarr 0+ transitions, whereas in the latter they are in disagreement with other known analyses of mu-meson capture, allowed and forbidden transitions. The conclusion appears to be independent...

  17. Impacted Lower Third Molar Fused with a Supernumerary Tooth —Diagnosis and Treatment Planning Using Cone-Beam Computed Tomography

    Science.gov (United States)

    Ferreira-Junior, Osny; de Ávila, Luciana Dorigatti; da Silva Sampieri, Marcelo Bonifácio; Dias-Ribeiro, Eduardo; Chen, Wei-liang; Fan, Song

    2009-01-01

    This paper reported a case of fusion between an impacted third molar and a supernumerary tooth, in which a surgical intervention was carried out, with the objective of removing the dental elements. The panoramic radiography was complemented by the Donovan's radiographic technique; but because of the proximity of the dental element to the mandibular ramus, it was not possible to have a final fusion diagnosis. Hence, the Cone-Beam Computed Tomography—which provides precise three-dimensional information—was used to determinate the fusion diagnosis and also to help in the surgical planning. In this case report we observed that the periapical, occlusal and panoramic were not able to show details which could only be examined through the cone-beam computed tomography. PMID:20690426

  18. A small supernumerary marker chromosome present in a Turner syndrome patient not derived from X- or Y-chromosome: a case report

    Directory of Open Access Journals (Sweden)

    Vermeesch Joris

    2009-11-01

    Full Text Available Abstract Background Small supernumerary marker chromosomes (sSMC can be present in numerically abnormal karyotypes like in a 'Turner-syndrome karyotype' mos 45,X/46,X,+mar. Results Here we report the first case of an sSMC found in Turner syndrome karyotypes (sSMCT derived from chromosome 14 in a Turner syndrome patient. According to cytogenetic and molecular cytogenetic characterization the karyotype was 46,X,+del(14(q11.1. The present case is the third Turner syndrome case with an sSMCT not derived from the X- or the Y-chromosome. Conclusion More comprehensive characterization of such sSMCT might identify them to be more frequent than only ~0.6% in Turner syndrome cases according to available data.

  19. Clean Elements in Abelian Rings

    Indian Academy of Sciences (India)

    Angelina Y M Chin

    2009-04-01

    Let be a ring with identity. An element in is said to be clean if it is the sum of a unit and an idempotent. is said to be clean if all of its elements are clean. If every idempotent in is central, then is said to be abelian. In this paper we obtain some conditions equivalent to being clean in an abelian ring.

  20. DELPHI's Ring Imaging Cherenkov Chamber

    CERN Multimedia

    1989-01-01

    The hundreds of mirrors around this Ring Imaging Cherenkov Chamber reflect cones of light created by fast moving particles to a detector. The velocity of a particle can be measured by the size of the ring produced on the detector. DELPHI, which ran from 1989 to 2000 on the LEP accelerator, was primarily concerned with particle identification.

  1. Pyrimidine-pyridine ring interconversion

    NARCIS (Netherlands)

    Plas, van der H.C.

    2003-01-01

    This chapter discusses the pyrimidine-to-pyridine ring transformation and pyridine-to-pyrimidine ring transformation. In nucleophile-induced pyrimidine-to-pyridine rearrangements, two types of reactions can be distinguished depending on the structure of the nucleophile: (1) reactions in which the ni

  2. Supercharacter theories and Schur rings

    CERN Document Server

    Hendrickson, Anders O F

    2010-01-01

    Diaconis and Isaacs have defined the supercharacter theories of a finite group to be certain approximations to the ordinary character theory of the group. We make explicit the connection between supercharacter theories and Schur rings, and we provide supercharacter theory constructions which correspond to Schur ring constructions of Leung and Man and of Tamaschke.

  3. Contraceptive vaginal rings: a review.

    Science.gov (United States)

    Brache, Vivian; Faundes, Anibal

    2010-11-01

    Development efforts on contraceptive vaginal rings were initiated over 40 years ago based on two principles: the capacity of the vaginal epithelium to absorb steroids and the capacity of elastomers to release these hormones at a nearly constant rate. Numerous models of contraceptive vaginal rings (CVRs) have been studied, but only two have reached the market: NuvaRing, a combined ring that releases etonogestrel (ENG) and ethinylestradiol (EE), and Progering, a progesterone-releasing ring for use in lactating women. The main advantages of CVRs are their effectiveness (similar to or slightly better than the pill), ease of use without the need of remembering a daily routine, user's ability to control initiation and discontinuation, nearly constant release rate allowing for lower doses, greater bioavailability and good cycle control with the combined ring. The main disadvantages are related to the mode of delivery; CVRs may cause vaginal discharge and complaints, ring expulsion is not uncommon, the ring may be felt during coitus and vaginal insertion may be unpleasant for some women. The studies reviewed in this article provide evidence that CVRs are safe, effective and highly acceptable to women. There is no doubt that CVRs offer a new, effective contraceptive option to women, expanding their available choices of hormonal contraception.

  4. Constructions over localizations of rings

    Directory of Open Access Journals (Sweden)

    Alessandro Logar

    1987-11-01

    Full Text Available In this paper we construct a category of effective noetherian rings in which linear equations can be “solved”. This category is closed with respect to some important constructions like trascendental extensions, quotientations, finite products and localizations with respect to a large class of multiplicatively closed systems. Hence it gives a definition of “constructive” rings.

  5. The Search for Ringed Exoplanets

    Science.gov (United States)

    Kohler, Susanna

    2017-04-01

    Are planetary rings as common in our galaxy as they are in our solar system? A new study demonstrates how we might search for ringed exoplanets and then possibly finds one!Saturns Elsewhere?Artists illustration of the super ring system around exoplanet J1407b. This is the only exoplanet weve found with rings, but its not at all like Saturn. [Ron Miller]Our solar system is filled with moons and planetary rings, so it stands to reason that exoplanetary systems should exhibit the same features. But though weve been in the planet-hunting game for decades, weve only found one exoplanet thats surrounded by a ring system. Whats more, that system J1407b has enormous rings that are vastly different from the modest, Saturn-like rings that we might expect to be more commonplace.Have we not discovered ringed exoplanets just because theyre hard to identify? Or is it because theyre not out there? A team of scientists led by Masataka Aizawa (University of Tokyo) has set out to answer this question by conducting a systematic search for rings around long-period planet candidates.The transit light curve of KIC 10403228, shown with three models: the best-fitting planet-only model (blue) and the two best-fitting planet+ring models (green and red). [Aizawa et al. 2017]The Hunt BeginsWhy long-period planets? Rings are expected to be unstable as the planet gets closer to the central star. Whats more, the planet needs to be far enough away from the stars warmth for the icy rings to exist. The authors therefore select from the collection of candidate transiting planets 89 long-period candidates that might be able to host rings.Aizawa and collaborators then fit single-planet models (with no rings) to the light curves of these planets and search for anomalies curves that arent fit well by these standard models. Particularly suspicious characteristics include a long ingress/egress as the planet moves across the face of the star, and asymmetry of the transit shape.After applying a series of

  6. Formation of polar ring galaxies

    CERN Document Server

    Bournaud, F

    2003-01-01

    Polar ring galaxies are peculiar systems in which a gas rich, nearly polar ring surrounds an early-type or elliptical host galaxy. Two formation scenarios for these objects have been proposed: they are thought to form either in major galaxy mergers or by tidal accretion of the polar material from a gas rich donor galaxy. Both scenarios are studied through N-body simulations including gas dynamics and star formation. Constraints on physical parameters are drawn out, in order to determine which scenario is the most likely to occur. Polar ring galaxies from each scenario are compared with observations and we discuss whether the accretion scenario and the merging scenario account for observational properties of polar ring galaxies. The conclusion of this study is that the accretion scenario is both the most likely and the most supported by observations. Even if the merging scenario is rather robust, most polar ring galaxies are shown to be the result of tidal gas accretion events.

  7. Ionization cooling ring for muons

    Directory of Open Access Journals (Sweden)

    R. Palmer

    2005-06-01

    Full Text Available Practical ionization cooling rings could lead to lower cost or improved performance in neutrino factory or muon collider designs. The ring modeled here uses realistic three-dimensional fields. The performance of the ring compares favorably with the linear cooling channel used in the second U.S. Neutrino Factory Study. The normalized 6D emittance of an ideal ring is decreased by a factor of approximately 240, compared with a factor of only 15 for the linear channel. We also examine such real-world effects as windows on the absorbers and rf cavities and leaving empty lattice cells for injection and extraction. For realistic conditions the ring decreases the normalized 6D emittance by a factor of 49.

  8. Studies of methanol maser rings

    CERN Document Server

    Bartkiewicz, A; van Langevelde, H J; De Buizer, J M; Pihlström, Y

    2011-01-01

    We present the results of studies of a new class of 6.7 GHz methanol maser sources with a ring-like emission structure discovered recently with the EVN. We have used the VLA to search for water masers at 22 GHz and radio continuum at 8.4 GHz towards a sample of high-mass star forming regions showing a ring-like distribution of methanol maser spots. Using the Gemini telescopes we found mid-infrared (MIR) counterparts of five methanol rings with a resolution of 0."15. The centres of methanol maser rings are located within, typically, only 0."2 of the MIR emission peak, implying their physical relation with a central star. These results strongly support a scenario wherein the ring-like structures appear at the very early stage of massive star formation before either water-maser outflows or H II regions are seen.

  9. A Note on Clean Rings

    Institute of Scientific and Technical Information of China (English)

    Zhou Wang; Jianlong Chen

    2007-01-01

    Let R be a ring and g(x) a polynomial in C[x],where C=C(R) denotes the center of R.Camillo and Sim6n called the ring g(x)-clean if every element of R can be written as the sum of a unit and a root of g(x).In this paper,we prove that for a,b (E) C,the ring R is clean and b - a is invertible in R if and only if R is g1(x)-clean,where gl(x) = (x - a)(x - b).This implies that in some sense the notion of g(x)-clean rings in the Nicholson-Zhou Theorem and in the Camillo-Sim6n Theorem is indeed equivalent to the notion of clean rings.

  10. Septins promote F-actin ring formation by crosslinking actin filaments into curved bundles.

    Science.gov (United States)

    Mavrakis, Manos; Azou-Gros, Yannick; Tsai, Feng-Ching; Alvarado, José; Bertin, Aurélie; Iv, Francois; Kress, Alla; Brasselet, Sophie; Koenderink, Gijsje H; Lecuit, Thomas

    2014-04-01

    Animal cell cytokinesis requires a contractile ring of crosslinked actin filaments and myosin motors. How contractile rings form and are stabilized in dividing cells remains unclear. We address this problem by focusing on septins, highly conserved proteins in eukaryotes whose precise contribution to cytokinesis remains elusive. We use the cleavage of the Drosophila melanogaster embryo as a model system, where contractile actin rings drive constriction of invaginating membranes to produce an epithelium in a manner akin to cell division. In vivo functional studies show that septins are required for generating curved and tightly packed actin filament networks. In vitro reconstitution assays show that septins alone bundle actin filaments into rings, accounting for the defects in actin ring formation in septin mutants. The bundling and bending activities are conserved for human septins, and highlight unique functions of septins in the organization of contractile actomyosin rings.

  11. Concise synthesis of the A/BCD-ring fragment of gambieric acid A

    Science.gov (United States)

    Fuwa, Haruhiko; Fukazawa, Ryo; Sasaki, Makoto

    2014-01-01

    Gambieric acid A (GAA) and its congeners belong to the family of marine polycyclic ether natural products. Their highly complex molecular architecture and unique biological activities have been of intense interest within the synthetic community. We have previously reported the first total synthesis, stereochemical reassignment, and preliminary structure–activity relationships of GAA. Here we disclose a concise synthesis of the A/BCD-ring fragment of GAA. The synthesis started from our previously reported synthetic intermediate that represents the A/B-ring. The C-ring was synthesized via an oxiranyl anion coupling and a 6-endo cyclization, and the D-ring was forged by means of an oxidative lactonization and subsequent palladium-catalyzed functionalization of the lactone ring. In this manner, the number of linear synthetic steps required for the construction of the C- and D-rings was reduced from 22 to 11. PMID:25629027

  12. Quantum Unique Ergodicity for Eisenstein Series on the Hilbert Modular Group over a Totally Real Field

    DEFF Research Database (Denmark)

    Truelsen, Jimi Lee

    W. Luo and P. Sarnak have proved quantum unique ergodicity for Eisenstein series on $PSL(2,Z) \\backslash H$. We extend their result to Eisenstein series on $PSL(2,O) \\backslash H^n$, where $O$ is the ring of integers in a totally real field of degree $n$ over $Q$ with narrow class number one, usi...

  13. Quantum unique ergodicity of Eisenstein series on the Hilbert modular group over a totally real field

    DEFF Research Database (Denmark)

    Truelsen, Jimi Lee

    2011-01-01

    W. Luo and P. Sarnak have proved the quantum unique ergodicity property for Eisenstein series on PSL(2, )\\. Their result is quantitative in the sense that they find the precise asymptotics of the measure considered. We extend their result to Eisenstein series on , where is the ring of integers in...

  14. Unique aspect of Tibetan medicine.

    Science.gov (United States)

    Dakpa, Tenzing

    2014-01-01

    Tibetan medicine is known as the knowledge of healing in the Four Tantras, the main medical text studied by Tibetan doctors. In the 8th century, King Trisong Deutsen (718-785 CE) invited eminent physicians from India, China, Persia, East Turkestan, Mongolia, and Nepal for the First International Medical Symposium in Samye, Tibet and ordered his personal physician Elder Yuthog Yonten Gonpo (708-833 CE), who lived 125 years, and participated in this conference to summarize. By combining all the information available and presented during this symposium, he compiled the Four Tantras. He established the Tanadug medical school at Menlung in Kongpo, Southern Tibet in 763 CE, and worked for the propagation of Tibetan medicine. He is considered an emanation of Medicine Buddha, who is a symbol of mental and physical well being. In his left hand, the Medicine Buddha clasps a begging bowl with long-life nectar, signifying immortality, and in his right, the Chebulic myrobalan (Haritaki), a symbol of good health. Chebulic myrobalan, Belleric myrobalan, and Emblic myrobalan are together called the "3 Fruits" and are common ingredients in Tibetan medicines. Prof. Omura, Y of NY Medical College evaluated these "3 Fruits" and found that one of them available as a "Haritaki," had the highest normal cell telomere increasing effect by optimal dose, with improvement of circulation all over the body, which in turn inhibits cancer activity. He considered Tibetan medicine to be the most advanced medicine in the world before the 19th Century with its well-organized systematic method as described by colorful Tibetan medical paintings by Sangye Gyamtso (1653-1705 CE). During a typical diagnosis, the physician examines the patients' tongue, radial arteries for pulse beats by the index, middle, and ring fingers of both hands and the urine for features like color, vapor, and bubbles, etc.

  15. Black Hole Ringing, Quasinormal Modes, and Light Rings

    CERN Document Server

    Khanna, Gaurav

    2016-01-01

    Modelling of gravitational waves from binary black hole inspiral has played an important role in the recent observations of such signals. The late-stage ringdown phase of the gravitational waveform is often associated with the null particle orbit (\\light ring") of the black hole spacetime. With simple models we show that this link between the light ring and spacetime ringing is based more on the history of applications than on an actual constraining relationship. We also show, in particular, that a better understanding of the disassociation between the two, may be relevant to the astrophysically interesting case of rotating (Kerr) black holes.

  16. Unique Features of Mobile Commerce

    Institute of Scientific and Technical Information of China (English)

    DING Xiaojun; IIJIMA Junichi; HO Sho

    2004-01-01

    While the market potentials and impacts of web-based e-commerce are still in the ascendant, the advances in wireless technologies and mobile networks have brought about a new business opportunity and research attention, what is termed mobile commerce. Commonly, mobile commerce is considered to be another new application of existing web-based e-commerce onto wireless networks, but as an independent business area, mobile commerce has its own advantages and challenges as opposed to traditional e-commerce applications. This paper focuses on exploring the unique features of mobile commerce as. Compared with traditional e-commerce. Also, there are still some limitations arisen in m-commerce in contrast to web-based e-commerce. Finally, current state of mobile commerce in Japan is presented in brief, with an introduction of several cases involving mobile commerce applications in today 's marketplace.

  17. Unique features of space reactors

    Science.gov (United States)

    Buden, David

    Space reactors are designed to meet a unique set of requirements; they must be sufficiently compact to be launched in a rocket to their operational location, operate for many years without maintenance and servicing, operate in extreme environments, and reject heat by radiation to space. To meet these restrictions, operating temperatures are much greater than in terrestrial power plants, and the reactors tend to have a fast neutron spectrum. Currently, a new generation of space reactor power plants is being developed. The major effort is in the SP-100 program, where the power plant is being designed for seven years of full power, and no maintenance operation at a reactor outlet operating temperature of 1350 K.

  18. The probabilities of unique events.

    Directory of Open Access Journals (Sweden)

    Sangeet S Khemlani

    Full Text Available Many theorists argue that the probabilities of unique events, even real possibilities such as President Obama's re-election, are meaningless. As a consequence, psychologists have seldom investigated them. We propose a new theory (implemented in a computer program in which such estimates depend on an intuitive non-numerical system capable only of simple procedures, and a deliberative system that maps intuitions into numbers. The theory predicts that estimates of the probabilities of conjunctions should often tend to split the difference between the probabilities of the two conjuncts. We report two experiments showing that individuals commit such violations of the probability calculus, and corroborating other predictions of the theory, e.g., individuals err in the same way even when they make non-numerical verbal estimates, such as that an event is highly improbable.

  19. The Evolution of Human Uniqueness.

    Science.gov (United States)

    Boyd, Robert

    2017-01-09

    The human species is an outlier in the natural world. Two million years ago our ancestors were a slightly odd apes. Now we occupy the largest ecological and geographical range of any species, have larger biomass, and process more energy. Usually, this transformation is explained in terms of cognitive ability-people are just smarter than all the rest. In this paper I argue that culture, our ability to learn from each other, and cooperation, our ability to make common cause with large groups of unrelated individuals are the real roots of human uniqueness, and sketch an evolutionary account of how these crucial abilities co-evolved with each other and with other features of our life histories.

  20. Is the bell ringing?

    CERN Multimedia

    Francesco Poppi

    2010-01-01

    During the Nobel prize-winning UA1 experiment, scientists in the control room used to ring a bell if a particularly interesting event had occurred. Today, the “CMS Exotica hotline” routine produces a daily report that lists the exotic events that were recorded the day before.   Display of an event selected by the Exotica routine. Take just a very small fraction of the available data (max. 5%); define the events that you want to keep and set the parameters accordingly; run the Exotica routine and only look at the very few images that the system has selected for you. This is the recipe that a small team of CMS researchers has developed to identify the signals coming from possible new physics processes. “This approach does not replace the accurate data analysis on the whole set of data. However, it is a very fast and effective way to focus on just a few events that are potentially very interesting”, explains Maurizio Pierini (CERN), who developed the...

  1. Anomalous Hollow Electron Beams in a Storage Ring

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Y.K.

    2005-04-12

    This paper reports the first observations of an anomalous hollow electron beam in the Duke storage ring. Created by exciting the single bunch beam in a lattice with a negative chromaticity, the hollow beam consists of a solid core inside and a large ring outside. We report the detailed measurements of the hollow beam phenomenon, including its distinct image pattern, spectrum signature, and its evolution with time. By capturing the post-instability bursting beam, the hollow beam is a unique model system for studying the transverse instabilities, in particular, the interplay of the wake field and the lattice nonlinearity. In addition, the hollow beam can be used as a powerful tool to study the linear and nonlinear particle dynamics in the storage ring.

  2. Stable ring resonator with bidirectional passes through the gain medium

    Science.gov (United States)

    Paxton, Alan H.; Miller, Harold C.

    2014-03-01

    Ring resonators have unique properties that are sometimes desirable. Spatial hole burning is eliminated. Beam transformation, such as image rotation which may reduce the magnitude of certain aberrations, can be implemented in a traveling-wave region. There is a drawback, however. As usually constructed, a ring resonator has half as many passes through the gain medium as can be achieved with a standing-wave resonator. This may have a detrimental effect on laser efficiency. We have constructed a type of ring resonator that allows counterpropagating collinear passes through the gain medium, while there is also a section with a unidirectional beam. The resonator includes a polarizing beam splitter. The linear polarization is transformed to the orthogonal state by optical elements at the two ends of the region with counter-propagating beams. The beams passing through the gain medium in opposite directions are linearly polarized with orthogonal states.

  3. Scores of RINGS but no PHDs in ubiquitin signaling.

    Science.gov (United States)

    Aravind, L; Iyer, L M; Koonin, E V

    2003-01-01

    Recently, it has been reported that PHD fingers of MEKK1 kinase and a family of viral and cellular membrane proteins have E3 ubiquitin ligase activity. Here we describe unique sequence and structural signatures that distinguish PHD fingers from RING fingers, which function primarily as E3 ubiquitin ligases, and demonstrate that the Zn-binding modules of the above proteins are distinct versions of the RING domain rather than PHD fingers. Thus, currently available data reveal extreme versatility of RINGs and their derivatives that function as E3 ubiquitin ligases but provide no evidence of this activity among PHD fingers whose principal function appears to involve specific protein-protein and possibly protein-DNA interactions in chromatin.

  4. Twin "Fano-Snowflakes" Over the Smallest Ring of Ternions

    CERN Document Server

    Saniga, Metod; Planat, Michel; Pracna, Petr

    2008-01-01

    Given a finite associative ring with unity, $R$, any free (left) cyclic submodule (FCS) generated by a $uni$modular ($n+1$)-tuple of elements of $R$ represents a point of the $n$-dimensional projective space over $R$. Suppose that $R$ also features FCSs generated by ($n+1$)-tuples that are $not$ unimodular: what kind of geometry can be ascribed to such FCSs? Here, we (partially) answer this question for $n=2$ when $R$ is the (unique) non-commutative ring of order eight. The corresponding geometry is dubbed a "Fano-Snowflake" due to its diagrammatic appearance and the fact that it contains the Fano plane in its center. There exist, in fact, two such configurations -- each being tied to either of the two maximal ideals of the ring -- which have the Fano plane in common and can, therefore, be viewed as twins. Potential relevance of these noteworthy configurations to quantum information theory and stringy black holes is also outlined.

  5. Optimal focusing of a beam in a ring vortex

    Science.gov (United States)

    Arrizón, Victor; Ruiz, Ulises; Aguirre-Olivas, Dilia; Mellado-Villaseñor, Gabriel

    2015-12-01

    Conventional light focusing, i.e. concentration of an extended optical field within a small area around a point, is a frequently used process in Optics. An important extension to conventional focusing is the generation of the annular focal field of an optical beam. We discuss a simple optical setup that achieves this kind of focusing employing a phase plate as unique optical component. It is assumed that the annular focal field is modulated by an azimuthal phase of integer order q that converts the field in a ring vortex. We first establish the class of beams that being transmitted through the phase plate can be focused into a ring vortex. Then, for each beam in this class we determine the plate transmittance that generates the vortex with the maximum possible intensity, which is referred to as optimal ring vortex.

  6. SPARC Collaboration: New Strategy for Storage Ring Physics at FAIR

    CERN Document Server

    Stöhlker, Thomas; Bräuning-Demian, Angela; Lestinsky, Michael; Herfurth, Frank; Maier, Rudolf; Prasuhn, Dieter; Schuch, Reinhold; Steck, Markus

    2014-01-01

    SPARC collaboration at FAIR pursues the worldwide unique research program by utilizing storage ring and trapping facilities for highly-charged heavy ions. The main focus is laid on the exploration of the physics at strong, ultra-short electromagnetic fields including the fundamental interactions between electrons and heavy nuclei as well as on the experiments at the border between nuclear and atomic physics. Very recently SPARC worked out a realization scheme for experiments with highly-charged heavy-ions at relativistic energies in the High-Energy Storage Ring HESR and at very low-energies at the CRYRING coupled to the present ESR. Both facilities provide unprecedented physics opportunities already at the very early stage of FAIR operation. The installation of CRYRING, dedicated Low-energy Storage Ring (LSR) for FLAIR, may even enable a much earlier realisation of the physics program of FLAIR with slow anti-protons.

  7. Ion Rings for Magnetic Fusion

    Energy Technology Data Exchange (ETDEWEB)

    Greenly, John, B.

    2005-07-31

    This Final Technical Report presents the results of the program, Ion Rings for Magnetic Fusion, which was carried out under Department of Energy funding during the period August, 1993 to January, 2005. The central objective of the program was to study the properties of field-reversed configurations formed by ion rings. In order to reach this objective, our experimental program, called the Field-reversed Ion Ring Experiment, FIREX, undertook to develop an efficient, economical technology for the production of field-reversed ion rings. A field-reversed configuration (FRC) in which the azimuthal (field-reversing) current is carried by ions with gyro-radius comparable to the magnetic separatrix radius is called a field-reversed ion ring. A background plasma is required for charge neutralization of the ring, and this plasma will be confined within the ring's closed magnetic flux. Ion rings have long been of interest as the basis of compact magnetic fusion reactors, as the basis for a high-power accelerator for an inertial fusion driver, and for other applications of high power ion beams or plasmas of high energy density. Specifically, the FIREX program was intended to address the longstanding question of the contribution of large-orbit ions to the observed stability of experimental FRCs to the MHD tilt mode. Typical experimental FRCs with s {approx} 2-4, where s is the ratio of separatrix radius to ion gyro-radius, have been stable to tilting, but desired values for a fusion reactor, s > 20, should be unstable. The FIREX ring would consist of a plasma with large s for the background ions, but with s {approx} 1 for the ring ions. By varying the proportions of these two populations, the minimum proportion of large-orbit ions necessary for stability could be determined. The incorporation of large-orbit ions, perhaps by neutral-beam injection, into an FRC has been advanced for the purpose of stabilizing, heating, controlling angular momentum, and aiding the formation

  8. Ideals in Morita Rings and Morita Semigroups

    Institute of Scientific and Technical Information of China (English)

    Yu Qun CHEN; Yun FAN; Zhi Feng HAO

    2005-01-01

    We characterize the lattice of all ideals of a Morita ring (semigroup) when the corresponding pair of rings (semigroups) in the Morita context are Morita equivalent s-unital (like-unity) rings(semigroups).

  9. Ring-Ringlet Interactions in Saturn's C Ring

    Science.gov (United States)

    Rappaport, N. J.

    1997-01-01

    The overall obejective of this work is to derive a theoretical model for the formation of gaps harboring isolated ringlets in order to explain the presence of such features in Saturn's C ring and Cassini division.

  10. Soft Congruence Relations over Rings

    Directory of Open Access Journals (Sweden)

    Xiaolong Xin

    2014-01-01

    Full Text Available Molodtsov introduced the concept of soft sets, which can be seen as a new mathematical tool for dealing with uncertainty. In this paper, we initiate the study of soft congruence relations by using the soft set theory. The notions of soft quotient rings, generalized soft ideals and generalized soft quotient rings, are introduced, and several related properties are investigated. Also, we obtain a one-to-one correspondence between soft congruence relations and idealistic soft rings and a one-to-one correspondence between soft congruence relations and soft ideals. In particular, the first, second, and third soft isomorphism theorems are established, respectively.

  11. Soft congruence relations over rings.

    Science.gov (United States)

    Xin, Xiaolong; Li, Wenting

    2014-01-01

    Molodtsov introduced the concept of soft sets, which can be seen as a new mathematical tool for dealing with uncertainty. In this paper, we initiate the study of soft congruence relations by using the soft set theory. The notions of soft quotient rings, generalized soft ideals and generalized soft quotient rings, are introduced, and several related properties are investigated. Also, we obtain a one-to-one correspondence between soft congruence relations and idealistic soft rings and a one-to-one correspondence between soft congruence relations and soft ideals. In particular, the first, second, and third soft isomorphism theorems are established, respectively.

  12. CYP1B1: a unique gene with unique characteristics.

    Science.gov (United States)

    Faiq, Muneeb A; Dada, Rima; Sharma, Reetika; Saluja, Daman; Dada, Tanuj

    2014-01-01

    CYP1B1, a recently described dioxin inducible oxidoreductase, is a member of the cytochrome P450 superfamily involved in the metabolism of estradiol, retinol, benzo[a]pyrene, tamoxifen, melatonin, sterols etc. It plays important roles in numerous physiological processes and is expressed at mRNA level in many tissues and anatomical compartments. CYP1B1 has been implicated in scores of disorders. Analyses of the recent studies suggest that CYP1B1 can serve as a universal/ideal cancer marker and a candidate gene for predictive diagnosis. There is plethora of literature available about certain aspects of CYP1B1 that have not been interpreted, discussed and philosophized upon. The present analysis examines CYP1B1 as a peculiar gene with certain distinctive characteristics like the uniqueness in its chromosomal location, gene structure and organization, involvement in developmentally important disorders, tissue specific, not only expression, but splicing, potential as a universal cancer marker due to its involvement in key aspects of cellular metabolism, use in diagnosis and predictive diagnosis of various diseases and the importance and function of CYP1B1 mRNA in addition to the regular translation. Also CYP1B1 is very difficult to express in heterologous expression systems, thereby, halting its functional studies. Here we review and analyze these exceptional and startling characteristics of CYP1B1 with inputs from our own experiences in order to get a better insight into its molecular biology in health and disease. This may help to further understand the etiopathomechanistic aspects of CYP1B1 mediated diseases paving way for better research strategies and improved clinical management.

  13. Annelation of furan rings to arenes

    Science.gov (United States)

    Omelchuk, O. A.; Tikhomirov, A. S.; Shchekotikhin, A. E.

    2016-08-01

    Benzo[b]furans have been used in various fields of chemistry and technology due to their unique physical, chemical and biological properties. It is primarily a wide range of biological activities of natural and synthetic benzo[b]furan derivatives and their polyfused analogues (naphthofurans, anthrafurans, etc.) that attracts a significant scientific interest in the context of using these heterocycles as privileged scaffolds in drug design. This survey covers those methods for the annelation of a furan ring to arenes that have been developed mostly during the last decade. We also analyze trends in synthetic methods of benzo[b]furans. Some synthetic schemes are highly efficient in the synthesis of polyfunctionalized furan derivatives. The bibliography includes 110 references.

  14. Differentials of Cox rings: Jaczewski's theorem revisited

    CERN Document Server

    Kedzierski, Oskar

    2011-01-01

    A generalized Euler sequence over a complete normal variety X is the unique "identity" extension of the trivial bundle H^1(X,\\Omega_X) \\otimes O_X by the sheaf of differentials \\Omega_X. We prove that, if X is a smooth Mori Dream Space and the bundle arising from the Euler sequence splits into a direct sum of line bundles, then X is a toric variety. The proof of this characterization of toric varieties depends on a somewhat more general result which, in the case of a Mori Dream Space, identifies the module of sections of the twisted sheaf coming from the Euler extension with the module of differentials of the Cox ring of the variety in question.

  15. Isochronicity Correction in the CR Storage Ring

    CERN Document Server

    Litvinov, S; Weick, H; Dolinskii, A

    2013-01-01

    A challenge for nuclear physics is to measure masses of exotic nuclei up to the limits of nuclear existence which are characterized by low production cross sections and short half-lives. The large acceptance Collector Ring (CR) at FAIR tuned in the isochronous ion-optical mode offers unique possibilities for measuring short-lived and very exotic nuclides. However, in a ring designed for maximal acceptance, many factors limit the resolution. One point is a limit in time resolution inversely proportional to the transverse emittance. But most of the time aberrations can be corrected and others become small for large number of turns. We show the relations of the time correction to the corresponding transverse focusing and that the main correction for large emittance corresponds directly to the chromaticity correction for transverse focusing of the beam. With the help of Monte-Carlo simulations for the full acceptance we demonstrate how to correct the revolution times so that in principle resolutions of dm/m=1E-6 ...

  16. Human genetics of the Kula Ring: Y-chromosome and mitochondrial DNA variation in the Massim of Papua New Guinea

    NARCIS (Netherlands)

    M. van Oven (Mannis); S. Brauer (Silke); Y. Choi (Ying); J. Ensing (Joe); W. Schiefenhövel (Wulf); M. Stoneking (Mark); M.H. Kayser (Manfred)

    2014-01-01

    textabstractThe island region at the southeastern-most tip of New Guinea and its inhabitants known as Massim are well known for a unique traditional inter-island trading system, called Kula or Kula Ring. To characterize the Massim genetically, and to evaluate the influence of the Kula Ring on

  17. Vibration insensitive optical ring cavity

    Institute of Scientific and Technical Information of China (English)

    Miao Jin; Jiang Yan-Yi; Fang Su; Bi Zhi-Yi; Ma Long-Sheng

    2009-01-01

    The mounting configuration of an optical ring cavity is optimized for vibration insensitivity by finite element analysis. A minimum response to vertical accelerations is found by simulations made for different supporting positions.

  18. Autumn study on storage rings

    CERN Multimedia

    1974-01-01

    The first two weeks of October have seen storage ring people from accelerator Laboratories throughout the world at CERN to study the fundamental problems of very high energy protonproton colliding beam machines.

  19. Ring Model for Pneumatic Tires

    Institute of Scientific and Technical Information of China (English)

    危银涛; 范成建; 管迪华

    2002-01-01

    This paper reviews the state-of-the-art of the ring modeling method for tires, emphasizing the differences among the various tire ring models. A general tire ring model was then developed including all the nonlinear terms in the ring strain and the initial stresses induced by the internal pressure and rotation. The general equations of motion were derived from the Hamilton principle whth the geometric parameters for the model directly obtained from the tire design. The physical parameters were calculated from experimental mode parameters. A numerical example is given for a 195/70 R14-type tire. The analysis shows that the predicted natural frequencies and the tire mode shape agree well with experimental results.

  20. Perturbations of vortex ring pairs

    CERN Document Server

    Gubser, Steven S; Parikh, Sarthak

    2015-01-01

    We study pairs of co-axial vortex rings starting from the action for a classical bosonic string in a three-form background. We complete earlier work on the phase diagram of classical orbits by explicitly considering the case where the circulations of the two vortex rings are equal and opposite. We then go on to study perturbations, focusing on cases where the relevant four-dimensional transfer matrix splits into two-dimensional blocks. When the circulations of the rings have the same sign, instabilities are mostly limited to wavelengths smaller than a dynamically generated length scale at which single-ring instabilities occur. When the circulations have the opposite sign, larger wavelength instabilities can occur.

  1. Synlig læring

    DEFF Research Database (Denmark)

    Brandsen, Mads

    2017-01-01

    Introduktionen af John Hatties synlig læring i den danske skoleverden møder stadig meget kritik. Mange lærere og pædagoger oplever synlig læring som en tornado, der vil opsuge og ødelægge deres særlige danske udgave af den kontinentale dannelsestænkning, didaktik og pædagogik. Spørgsmålet er om...

  2. Commuting Π-regular rings

    Directory of Open Access Journals (Sweden)

    Shervin Sahebi

    2014-05-01

    Full Text Available ‎$R$ is called commuting regular ring (resp‎. ‎semigroupif‎ for each $x,y\\in R$ there exists $a\\in R$‎ such that$xy=yxayx$‎. ‎In this paper‎, ‎we introduce the concept of‎‎commuting $\\pi$-regular rings (resp‎. ‎semigroups and‎‎study various properties of them.

  3. 锥形束CT对埋伏多生牙定位的临床应用价值%Clinical application of cone-beam computer tomography in location of impacted supernumerary teeth

    Institute of Scientific and Technical Information of China (English)

    李辉; 王丽君; 李泽奎

    2012-01-01

    目的:探讨锥形束CT在埋伏多生牙定位中的应用价值.方法:对39例(42颗多生牙)经常规X线检查无法定位的埋伏多生牙患者做回顾性分析.经锥形束CT扫描,通过三维重建进行观察.结果:锥形束CT能准确定位多生牙的方向、数量及与邻近组织的空间位置关系.结论:锥形束CT可以直观、准确地对埋伏多生牙定位,对临床手术路径的确定、治疗方案的选择有重要应用价值.%Objective: To investigate the clinical application of cone-beam computer tomography in impacted supernumerary teeth location. Methods: 39 patients (with 42 supernumerary teeth) who had been examined by conventional X-ray examination with none location result, were scaned by cone-beam computer tomography and observed in three-dimensional reconstruction. Results: Cone-beam computer tomography possessed the advantages in three dimensional location,amount of the supernumerary teeth, and spital relationship with adjacent structures. Conclusion: Cone-beam computer tomography is intuitive and accurate positioning impacted supernumerary teeth, which has an important application value in surgical access option and treatment plan instruction.

  4. History of Neptune's Ring Arcs

    Science.gov (United States)

    Esposito, L. W.; Colwell, J. E.; Canup, R. M.

    1997-07-01

    The recent dynamical calculations for Neptune's Adams ring arcs by Foryta and Sicardy (1996) and Hanninen and Porco (1997) determine the basic evolutionary parameters for this system. The ring evolution is dominated by stochastic events, particularly chaotic motion that causes a migration between the corotation sites (FS96) and collisions near quadrature (HP97). A basic problem is that the high velocity collisions that produce the dusty arcs at the Galatea corotation resonances rapidly depopulate these sites (Colwell and Esposito 1990). With the new results in hand for the evolution of the ring particles over periods of less than a century, we can now calculate the long-term stochastic evolution of the Adams ring. Using a finite Markov chain as a model for this stochastic process, we follow the suggestion by FS96 that corotation sites provide preferential locations for accretion. A more general conclusion is that the longitudinal concentration of material in a few nearby sites (and that the majority of the Adams ring material is residing there) requires either an exceedingly recent event (EC92) or that the corotation sites be absorbing states of the Markov chain.In the latter case, the competing processes of chaotic diffusion and frustrated accretion can provide the arc and clump features as recurrent transient events near the Roche limit. Similar phenomena would be expected for Saturn's F and G rings.

  5. The ring of the narcissist.

    Science.gov (United States)

    Shengold, L

    1995-12-01

    The author has not attempted a complete exposition of the meaning of rings--which can refer to and symbolise many aspects of relationships with other human beings from 'transitional objects' of early development (Winnicott) to all sorts of bonds of loyalty, friendship, and love in the life of the child and the adult. He stresses the meanings of the ring from the point of view of early narcissistic development--the 'body ego' time of early development in which symbolism (in Freud's sense) develops. The clinical and literary examples therefore illustrate the use of rings as magical narcissistic symbols--part subject and part object--derived developmentally from the body ego and ultimately from the body sphincters. Endowed with these regressive primitive meanings, rings are felt to have magical powers that can either preserve or destroy, and that can control emotions in the self and in others. In the course of ordinary or pathological narcissistic regressions, rings (consciously associated with many positive feelings and achievements) also partake, in so far as they are 'Freudian' symbols, of qualities associated with developmentally early defensive mechanisms and modes of psychic functioning (projection, introjection; idealisation, devaluation). In the cases cited, rings seemed specifically associated with (and to symbolise) sphincteric (largely anal) narcissistic defensiveness--the mind functioning as an emotional sphincteric counterpart primarily deadening and distancing affect but intermittently letting through primitive rage and primal polymorphous perverse sexual impulses.

  6. Collar nut and thrust ring

    Science.gov (United States)

    Lowery, Guy B.

    1991-01-01

    A collar nut comprises a hollow cylinder having fine interior threads at one end for threadably engaging a pump mechanical seal assembly and an inwardly depending flange at the other end. The flange has an enlarged portion with a groove for receiving an O-ring for sealing against the intrusion of pumpage from the exterior. The enlarged portion engages a thrust ring about the pump shaft for crushing a hard O-ring, such as a graphite O-ring. The hard O-ring seals the interior of the mechanical seal assembly and pump housing against the loss of lubricants or leakage of pumpage. The fine threads of the hollow cylinder provide the mechanical advantage for crushing the hard O-ring evenly and easily with a hand tool from the side of the collar nut rather than by tightening a plurality of bolts from the end and streamlines the exterior surface of the mechanical seal. The collar nut avoids the spatial requirements of bolt heads at the end of a seal and associated bolt head turbulence.

  7. Accretion in Saturn's F Ring

    Science.gov (United States)

    Meinke, B. K.; Esposito, L. W.; Stewart, G.

    2012-12-01

    Saturn's F ring is the solar system's principal natural laboratory for direct observation of accretion and disruption processes. The ring resides in the Roche zone, where tidal disruption competes with self-gravity, which allows us to observe the lifecycle of moonlets. Just as nearby moons create structure at the B ring edge (Esposito et al. 2012) and the Keeler gap (Murray 2007), the F ring "shepherding" moons Prometheus and Pandora stir up ring material and create observably changing structures on timescales of days to decades. In fact, Beurle et al (2010) show that Prometheus makes it possible for "distended, yet gravitationally coherent clumps" to form in the F ring, and Barbara and Esposito (2002) predicted a population of ~1 km bodies in the ring. In addition to the observations over the last three decades, the Cassini Ultraviolet Imaging Spectrograph (UVIS) has detected 27 statistically significant features in 101 occultations by Saturn's F ring since July 2004. Seventeen of those 27 features are associated with clumps of ring material. Two features are opaque in occultation, which makes them candidates for solid objects, which we refer to as Moonlets. The 15 other features partially block stellar signal for 22 m to just over 3.7 km along the radial expanse of the occultation. Upon visual inspection of the occultation profile, these features resemble Icicles, thus we will refer to them as such here. The density enhancements responsible for such signal attenuations are likely due to transient clumping of material, evidence that aggregations of material are ubiquitous in the F ring. Our lengthy observing campaign reveals that Icicles are likely transient clumps, while Moonlets are possible solid objects. Optical depth is an indicator of clumping because more-densely aggregated material blocks more light; therefore, it is natural to imagine moonlets as later evolutionary stage of icicle, when looser clumps of material compact to form a feature that appears

  8. UNIQUENESS ON ZERO PRESSURE GAS DYNAMICS

    Institute of Scientific and Technical Information of China (English)

    黄飞敏; 王振

    2001-01-01

    By introducing a new idea, the authors prove the uniqueness of weak solution of pressureless gases with the large initial data. In particular, uniqueness theorem is obtained in the same functional space as the existence theorem.

  9. The rings of Saturn: State of current knowledge and some suggestions for future studies

    Science.gov (United States)

    Cuzzi, J. N.

    1978-01-01

    The state of our current knowledge of the properties of the ring system as a whole, and of the particles individually, is assessed. Attention is primarily devoted to recent results and possibilities for exploration of the ring system by a Saturn orbiter. In particular, the infrared and microwave properties of the ring system are discussed. The behavior of the ring brightness is not well understood in the critical transition spectral region from approximately 100 micrometers to approximately 1 cm. Also, the dynamical behavior of the ring system is discussed. Recent theoretical studies show that ongoing dynamical effects continually affect the ring structure in azimuth (possibly producing the A ring brightness asymmetry) and in the vertical direction. Orbital spacecraft-based studies of the rings will offer several unique advantages and impact important cosmogonical questions. Bistatic radar studies and millimeter-wavelength spectrometer/radiometry will give particle sizes and composition limits needed to resolve the question of the density of the rings, and provide important boundary conditions on the state of Saturn's protoplanetary nebula near the time of planetary formation.

  10. Double acting stirling engine piston ring

    Science.gov (United States)

    Howarth, Roy B.

    1986-01-01

    A piston ring design for a Stirling engine wherein the contact pressure between the piston and the cylinder is maintained at a uniform level, independent of engine conditions through a balancing of the pressure exerted upon the ring's surface and thereby allowing the contact pressure on the ring to be predetermined through the use of a preloaded expander ring.

  11. On the uniqueness of supersymmetric attractors

    Directory of Open Access Journals (Sweden)

    Taniya Mandal

    2015-10-01

    Full Text Available In this paper we discuss the uniqueness of supersymmetric attractors in four-dimensional N=2 supergravity theories coupled to n vector multiplets. We prove that for a given charge configuration the supersymmetry preserving axion free attractors are unique. We generalise the analysis to axionic attractors and state the conditions for uniqueness explicitly. We consider the example of a two-parameter model and find all solutions to the supersymmetric attractor equations and discuss their uniqueness.

  12. Extensions and Pullbacks in QB-rings

    OpenAIRE

    Ara, Pere; Pedersen, Gert K.; Perera, Francesc

    2001-01-01

    We prove a new extension result for $QB-$rings that allows us to examine extensions of rings where the ideal is purely infinite and simple. We then use this result to explore various constructions that provide new examples of $QB-$rings. More concretely, we show that a surjective pullback of two $QB-$rings is usually again a $QB-$ring. Specializing to the case of an extension of a semi-prime ideal $I$ of a unital ring $R$, the pullback setting leads naturally to the study of rings whose multi...

  13. The ribbon of the rings: the stability of the rings

    Science.gov (United States)

    Florinski, V.

    2016-11-01

    The astounding result of the Voyager 1 observations in the outer heliosheath region is the Kolmogorov-like spectrum of magnetic fluctuations, consistent with the ambient spectrum of interstellar turbulence deduced from remote sensing. Such quiet conditions appear to be incompatible with the ionization of the neutral solar wind hydrogen atoms by charge exchange, which would generate abundant turbulent fluctuations due to an instability of the resulting proton ring. Here we revisit the problem of stability of ring and shell distributions embedded in a warm plasma characteristic of the outer heliosheath. We show that ion rings with parallel velocity dispersion between a few km/s and the core thermal speed are stable, while those outside these bounds are subject to magnetic-fluctuation-producing left- and righthanded instabilities. Wave generation by the instability is too efficient to be transported to shorter scales and converted into heat by the turbulent cascade.

  14. 77 FR 69393 - Unique Device Identification System

    Science.gov (United States)

    2012-11-19

    ... HUMAN SERVICES Food and Drug Administration 21 CFR Part 801 RIN 0910-AG31 Unique Device Identification... unique device identification system as required by recent amendments to the Federal Food, Drug, and..., FDA published a proposed rule to establish a unique device identification system, as required by...

  15. On chromatic and flow polynomial unique graphs

    National Research Council Canada - National Science Library

    Duan, Yinghua; Wu, Haidong; Yu, Qinglin

    2008-01-01

    ... research on graphs uniquely determined by their chromatic polynomials and more recently on their Tutte polynomials, but rather spotty research on graphs uniquely determined by their flow polynomials or the combination of both chromatic and flow polynomials. This article is an initiation of investigation on graphs uniquely determin...

  16. Mathematical analysis of a model for moon-triggered clumping in Saturn's rings

    CERN Document Server

    Torres, Pedro J; Esposito, Larry W

    2013-01-01

    Spacecraft observations of Saturn's rings show evidence of an active aggregation-disaggregation process triggered by periodic influences from the nearby moons. This leads to clumping and break-up of the ring particles at time-scales of the order of a few hours. A mathematical model has been developed to explain these dynamics in the Saturn's F-ring and B-ring [3], the implications of which are in close agreement with the empirical results. In this paper, we conduct a rigorous analysis of the proposed forced dynamical system for a class of continuous, periodic and zero-mean forcing functions that model the ring perturbations caused by the moon flybys. In specific, we derive the existence of at least one periodic solution to the dynamic system with the period equal to the forcing period of the moon. Further, conditions for the uniqueness and stability of the solution and bounds for the amplitudes of the periodic solution are derived.

  17. Nerve ring of the hypostome in hydra. I. Its structure, development, and maintenance

    DEFF Research Database (Denmark)

    Koizumi, O; Itazawa, M; Mizumoto, H

    1992-01-01

    neuronal complex consisting of a thick nerve bundle running circumferentially at the border between the hypostome and tentacle zone. Immunostaining showed that the nerve ring was heterogeneous and contained at least four different subsets of neurons. During head regeneration and budding, the nerve ring......The anatomy and developmental dynamics of the nerve ring in the hypostome of Hydra oligactis were examined immunocytochemically with an antiserum against a neuropeptide and with neuron-specific monoclonal antibodies. The nerve ring is unique in the mesh-like nerve net of hydra. It is a distinct...... appeared only after the nerve net of ganglion and sensory cells had formed. Every epithelial cell is continuously displaced with neurons toward either head or foot in an adult hydra. However, the ectoderm in the immediate vicinity of, and including, the nerve ring constitutes a stationary zone...

  18. Intrinsic structure in Saturn's rings

    Science.gov (United States)

    Albers, N.

    2015-10-01

    Saturn's rings are the most prominent in our Solar system and one example of granular matter in space. Dominated by tides and inelastic collisions the system is highly flattened being almost 300000km wide while only tens of meters thick. Individual particles are composed of primarily water ice and range from microns to few tens of meters in size. Apparent patterns comprise ringlets, gaps, kinematic wakes, propellers, bending waves, and the winding spiral arms of density waves. These large-scale structures are perturbations foremost created by external as well as embedded moons. Observations made by the Cassini spacecraft currently in orbit around Saturn show these structures in unprecedented detail. But high-resolution measurements reveal the presence of small-scale structures throughout the system. These include self-gravity wakes (50-100m), overstable waves (100-300m), subkm structure at the A and B ring edges, "straw" and "ropy" structures (1-3km), and the C ring "ghosts". Most of these had not been anticipated and are found in perturbed regions, driven by resonances with external moons, where the system undergoes periodic phases of compression and relaxation that correlate with the presence of structure. High velocity dispersion and the presence of large clumps imply structure formation on time scales as short as one orbit (about 10 hours). The presence of these intrinsic structures is seemingly the response to varying local conditions such as internal density, optical depth, underlying particle size distribution, granular temperature, and distance from the central planet. Their abundance provides evidence for an active and dynamic ring system where aggregation and fragmentation are ongoing on orbital timescales. Thus a kinetic description of the rings may be more appropriate than the fluid one. I will present Cassini Ultraviolet Spectrometer (UVIS) High Speed Photometer (HSP) occultations, Voyager 1 and 2 Imaging Science Subsystem (ISS), and high

  19. Ring wormholes via duality rotations

    Directory of Open Access Journals (Sweden)

    Gary W. Gibbons

    2016-09-01

    Full Text Available We apply duality rotations and complex transformations to the Schwarzschild metric to obtain wormhole geometries with two asymptotically flat regions connected by a throat. In the simplest case these are the well-known wormholes supported by phantom scalar field. Further duality rotations remove the scalar field to yield less well known vacuum metrics of the oblate Zipoy–Voorhees–Weyl class, which describe ring wormholes. The ring encircles the wormhole throat and can have any radius, whereas its tension is always negative and should be less than −c4/4G. If the tension reaches the maximal value, the geometry becomes exactly flat, but the topology remains non-trivial and corresponds to two copies of Minkowski space glued together along the disk encircled by the ring. The geodesics are straight lines, and those which traverse the ring get to the other universe. The ring therefore literally produces a hole in space. Such wormholes could perhaps be created by negative energies concentrated in toroidal volumes, for example by vacuum fluctuations.

  20. Dream of Isochronous Ring Again

    CERN Document Server

    Hama, H

    2005-01-01

    More than 20 years ago, D.A.G. Deacon proposed an isochronous storage ring for FEL to avoid bunch heating and decreasing instantaneous gain [1]. Some of low momentum compaction (alpha) operations have been carried out, and recently coherent infrared radiation are observed on a 3rd generation light source. Because the 3rd generation rings are optimized to obtain very low emittance beam, the dispersion function in the arc sections are much reduced by introducing large bending radius, so that those are very big machines. Meanwhile N.A. Vinokurov et al. recently proposed a ring type SASE FEL based on a complete isochronous bending transport [2]. At least, experimental and theoretical study of the isochronous ring so far suggests nonlinear effects resulted from higher order dispersion and chromaticity declines the "complete" isochronous system. On the other hand, in a wavelength region of THz, tolerance of the path length along a turn of the ring seems to be within our reach. A concept to preserve of a form factor...

  1. Ring polymers in confined geometries

    CERN Document Server

    Usatenko, Z; Kuterba, P

    2016-01-01

    The investigation of a dilute solution of phantom ideal ring polymers and ring polymers with excluded volume interactions (EVI) in a good solvent confined in a slit geometry of two parallel repulsive walls and in a solution of colloidal particles of big size were performed. Taking into account the correspondence between the field theoretical $\\phi^4$ $O(n)$-vector model in the limit $n\\to 0$ and the behavior of long-flexible polymer chains in a good solvent the correspondent depletion interaction potentials, depletion forces and the forces which exert phantom ideal ring and ring polymer chains with EVI on the walls were obtained in the framework of the massive field theory approach at fixed space dimensions d=3 up to one-loop order. Additionally, the investigation of a dilute solution of phantom ideal ring polymers in a slit geometry of two inert walls and mixed walls with one repulsive and other one inert wall were performed and correspondent depletion interaction potentials and the depletion forces were cal...

  2. Ring wormholes via duality rotations

    CERN Document Server

    Gibbons, Gary W

    2016-01-01

    We apply duality rotations and complex transformations to the Schwarzschild metric to obtain wormhole geometries with two asymptotically flat regions connected by a throat. In the simplest case these are the well-known wormholes supported by phantom scalar field. Further duality rotations remove the scalar field to yield less well known vacuum metrics of the oblate Zipoy-Voorhees-Weyl class, which describe ring wormholes. The ring encircles the wormhole throat and can have any radius, whereas its tension is always negative and should be less than $-c^4/4G$. If the tension reaches the maximal value, the geometry becomes exactly flat, but the topology remains non-trivial and corresponds to two copies of Minkowski space glued together along the disk encircled by the ring. The geodesics are straight lines, and those which traverse the ring get to the other universe. The ring therefore literally produces a whole in space. Such wormholes could perhaps be created by negative energies concentrated in toroidal volumes...

  3. CYCLIC CODES OVER FORMAL POWER SERIES RINGS

    Institute of Scientific and Technical Information of China (English)

    Dougherty Steven T.; Liu Hongwei

    2011-01-01

    In this article, cyclic codes and negacyclic codes over formal power series rings are studied. The structure of cyclic codes over this class of rings is given, and the relationship between these codes and cyclic codes over finite chain rings is obtained. Using an isomorphism between cyclic and negacyclic codes over formal power series rings, the structure of negacyclic codes over the formal power series rings is obtained.

  4. Multiplex ligation dependent probe amplification (MLPA) for rapid distinction between unique sequence positive and negative marker chromosomes in prenatal diagnosis

    NARCIS (Netherlands)

    D. van Opstal (Diane); M. Boter (Marjan); P. Noomen (Petra); M. Srebniak (Malgorzata); G. Hamers (Guus); R-J.H. Galjaard (Robert-Jan)

    2011-01-01

    textabstractBackground: Small supernumerary marker chromosomes (sSMC) are extra structurally abnormal chromosomes that cannot be unambiguously identified with conventional chromosome banding techniques. These marker chromosomes may cause an abnormal phenotype or be harmless depending on different fa

  5. Traversable wormholes the Roman ring

    CERN Document Server

    Visser, M

    1997-01-01

    In this brief report I introduce a yet another class of geometries for which semi-classical chronology protection theorems are of dubious physical reliability. I consider a ``Roman ring'' of traversable wormholes, wherein a number of wormholes are arranged in a ring in such a manner that no subset of wormholes is near to chronology violation, though the combined system can be arbitrarily close to chronology violation. I show that (with enough wormholes in the ring) the gravitational vacuum polarization (the expectation value of the quantum stress-energy tensor) can be made arbitrarily small. In particular the back-reaction can be kept arbitrarily small all the way to the ``reliability horizon''---so that semi-classical quantum gravity becomes unreliable before the gravitational back reaction becomes large.

  6. Fusión de un tercer molar mandibular con un cuarto molar supernumerario Fusion of mandibular third molar with supernumerary fourth molar

    Directory of Open Access Journals (Sweden)

    C. López Carriches

    2008-10-01

    Full Text Available La fusión dental es la unión de dos gérmenes dentales normalmente separados, mientras que la geminación se define como el intento de división de un único germen dental. La fusión y geminación de molares es poco frecuente en la dentición permanente. Describimos un caso clínico de un tercer molar inferior derecho fusionado a un cuarto molar supernumerario en un paciente varón de 36 años que ha presentado repetidos episodios de pericoronaritis. Tras el estudio radiológico se realiza la exodoncia del cordal semiincluido bajo anestesia local. Llevamos a cabo una revisión bibliográfica al respecto.Dental fusion is the union of two tooth buds that normally are separated, while gemination is defined as an attempt by a single tooth bud to divide. The fusion and gemination of molars is uncommon in permanent teeth. We report a clinical case of a right lower third molar fused to a supernumerary fourth molar in a 36-year-old male patient with repeated episodes of inflammation. After the radiologic study, the semi-impacted third molar was extracted under local anesthesia. The literature was reviewed.

  7. Dissecting the phenotype of supernumerary marker chromosome 20 in a patient with syndromic Pierre Robin sequence: combinatorial effect of gene dosage and uniparental disomy.

    Science.gov (United States)

    Izumi, Kosuke; Kubota, Noriko; Arakawa, Michiko; Takayama, Masayoshi; Harada, Yukiko; Nakamura, Tomohiko; Nishi, Eriko; Hidaka, Eiko

    2015-06-01

    Clinical phenotypes in individuals with a supernumerary marker chromosome (SMC) are mainly caused by gene dosage effects due to the genes located on the SMC. An additional effect may result from uniparental disomy (UPD). Consequently, the occurrence of UPD may be a confounding factor in identifying genotype-phenotype correlations in SMC syndromes. Here, we report on a patient that illustrates this problem; the phenotype of this patient was a consequence of a combined effect of gene dosage and UPD. The proband showed facial dysmorphisms, growth retardation and developmental delay. G-band karyotype of the proband's peripheral blood showed the presence of mosaic SMC. A SNP array analysis documented maternal UPD20 and 20p duplication. It is known that maternal UPD20 causes prenatal onset growth retardation and feeding difficulties. By contrast, duplication of 20p causes facial dysmorphisms, micrognathia, cleft palate, developmental delay and vertebral anomalies. Our classification of the proband's phenotype showed a mixture of these two effects. Therefore, we suggest the routine use of genome-wide SNP array towards the detailed genotype-phenotype correlations for SMC syndromes.

  8. Co-occurrence of mosaic supernumerary isochromosome 18p and intermittent 2q13 deletions in a child with multiple congenital anomalies.

    Science.gov (United States)

    Jaiswal, Sushil Kumar; Kumar, Ashok; Ali, Akhtar; Rai, Amit Kumar

    2015-03-15

    The present study deals with karyotpye-phenotype correlations in a six month old child with multiple congenital abnormalities. Cytogenetic analysis revealed mosaicism of a small metacentric supernumerary marker chromosome with a karyotype mos 47,XY+mar[34]/46,XY[31]. Cytogenetic microarray result showed three copies of chromosome 18p (15,400 kb in size). Moreover, 255 kbp intermittent deletion of chromosome 2q13 involving RGPD5, RGPD6, LIMS3, and LIMS3-LOC440895 was also observed. Correlating microarray data with the mosaic karyotype, the marker chromosome was identified as mosaic isochromosome 18p and was found to be 32,600 kbp in size. Baby resembled clinical characteristics of trisomy chromosome 18p, isochromosome 18p and trisomy chromosome 18. The present study suggested that deletion of evolutionarily conserved developmental genes (RGPD5, RGPD and LIMS3) in the 2q13 region might have contributed to more severity in phenotype as compared to so far such reported cases of 18p trisomy's, as these are involved in nuclear-cytoplasm trafficking, signaling for tissue patterning and differentiation.

  9. Genetic dosage and position effect of small supernumerary marker chromosome (sSMC) in human sperm nuclei in infertile male patient.

    Science.gov (United States)

    Olszewska, Marta; Wanowska, Elzbieta; Kishore, Archana; Huleyuk, Nataliya; Georgiadis, Andrew P; Yatsenko, Alexander N; Mikula, Mariya; Zastavna, Danuta; Wiland, Ewa; Kurpisz, Maciej

    2015-11-30

    Chromosomes occupy specific distinct areas in the nucleus of the sperm cell that may be altered in males with disrupted spermatogenesis. Here, we present alterations in the positioning of the human chromosomes 15, 18, X and Y between spermatozoa with the small supernumerary marker chromosome (sSMC; sSMC(+)) and spermatozoa with normal chromosome complement (sSMC(-)), for the first time described in the same ejaculate of an infertile, phenotypically normal male patient. Using classical and confocal fluorescent microscopy, the nuclear colocalization of chromosomes 15 and sSMC was analyzed. The molecular cytogenetic characteristics of sSMC delineated the karyotype as 47,XY,+der(15)(pter->p11.2::q11.1->q11.2::p11.2->pter)mat. Analysis of meiotic segregation showed a 1:1 ratio of sSMC(+) to sSMC(-) spermatozoa, while evaluation of sperm aneuploidy status indicated an increased level of chromosome 13, 18, 21 and 22 disomy, up to 7 × (2.7 - 15.1). Sperm chromatin integrity assessment did not reveal any increase in deprotamination in the patient's sperm chromatin. Importantly, we found significant repositioning of chromosomes X and Y towards the nuclear periphery, where both chromosomes were localized in close proximity to the sSMC. This suggests the possible influence of sSMC/XY colocalization on meiotic chromosome division, resulting in abnormal chromosome segregation, and leading to male infertility in the patient.

  10. Tree rings and radiocarbon calibration

    Energy Technology Data Exchange (ETDEWEB)

    Barbetti, M. [University of Sydney, Sydney, NSW (Australia). NWG Macintosh Centre for Quaternary Dating

    1999-11-01

    Only a few kinds of trees in Australia and Southeast Asia are known to have growth rings that are both distinct and annual. Those that do are therefore extremely important to climatic and isotope studies. In western Tasmania, extensive work with Huon pine (Lagarostrobos franklinii) has shown that many living trees are more than 1,000 years old, and that their ring widths are sensitive to temperature, rainfall and cloud cover (Buckley et al. 1997). At the Stanley River there is a forest of living (and recently felled) trees which we have sampled and measured. There are also thousands of subfossil Huon pine logs, buried at depths less than 5 metres in an area of floodplain extending over a distance of more than a kilometre with a width of tens of metres. Some of these logs have been buried for 50,000 years or more, but most of them belong to the period between 15,000 years and the present. In previous expeditions in the 1980s and 1990s, we excavated and sampled about 350 logs (Barbetti et al. 1995; Nanson et al. 1995). By measuring the ring-width patterns, and matching them between logs and living trees, we have constructed a tree-ring dated chronology from 571 BC to AD 1992. We have also built a 4254-ring floating chronology (placed by radiocarbon at ca. 3580 to 7830 years ago), and an earlier 1268-ring chronology (ca. 7,580 to 8,850 years ago). There are many individuals, or pairs of logs which match and together span several centuries, at 9,000 years ago and beyond 15 refs., 1 tab., 1 fig.

  11. Multiplex ligation dependent probe amplification (MLPA for rapid distinction between unique sequence positive and negative marker chromosomes in prenatal diagnosis

    Directory of Open Access Journals (Sweden)

    Hamers Guus

    2011-01-01

    Full Text Available Abstract Background Small supernumerary marker chromosomes (sSMC are extra structurally abnormal chromosomes that cannot be unambiguously identified with conventional chromosome banding techniques. These marker chromosomes may cause an abnormal phenotype or be harmless depending on different factors such as genetic content, chromosomal origin and level of mosaicism. When a sSMC is found during prenatal diagnosis, the main question is whether the sSMC contains euchromatin since in most cases this will lead to phenotypic abnormalities. We present the use of Multiplex Ligation Dependent probe Amplification (MLPA for rapid distinction between non-euchromatic and euchromatic sSMC. Results 29 well-defined sSMC found during prenatal diagnosis were retrospectively investigated with MLPA with the SALSA MLPA centromere kits P181 and P182 as well as with the SALSA MLPA telomere kits P036B and P070 (MRC Holland BV, Amsterdam, The Netherlands. All unique-sequence positive sSMC were correctly identified with MLPA, whereas the unique-sequence negative sSMC had normal MLPA results. Conclusions Although different techniques exist for identification of sSMC, we show that MLPA is a valuable adjunctive tool for rapidly distinguishing between unique-sequence positive and negative sSMC. In case of positive MLPA results, genetic microarray analysis or, if not available, targeted FISH can be applied for further identification and determination of the exact breakpoints, which is important for prediction of the fetal phenotype. In case of a negative MLPA result, which means that the sSMC most probably does not contain genes, the parents can already be reassured and parental karyotyping can be initiated to assess the heritability. In the mean time, FISH techniques are needed for determination of the chromosomal origin.

  12. On Simple-Injective Rings

    Institute of Scientific and Technical Information of China (English)

    W.K. Nicholson; Jae Keol Park; M.F. Yousif

    2002-01-01

    A ring R is called right simple-injective if every R-linear map from a right ideal of R to R with simple image can be extended to R. It is shown that a right simple-injective ring R is quasi-Frobenius if R is right Goldie with essential right socle, or R is left perfect and the right annihilator of k ∈ R is finitely generated whenever kR or Rk is simple. This extends a result of Bjork.

  13. On Ideals of Regular Rings

    Institute of Scientific and Technical Information of China (English)

    CHEN Huan Yin; LI Fu An

    2002-01-01

    In this paper, we investigate ideals of regular rings and give several characterizations for an ideal to satisfy the comparability. In addition, it is shown that, if Ⅰ is a minimal two-sided ideal of a regular ring R, then Ⅰ satisfies the comparability if and only if Ⅰ is separative. Furthermore, we prove that, for ideals with stable range one, Roth's problem has an affirmative solution. These extend the corresponding results on unit-regularity and one-sided unit-regularity.

  14. Nanoscale nonlinear PANDA ring resonator

    CERN Document Server

    Yupapin, Preecha

    2012-01-01

    Microring/nanoring resonator is an interesting device that has been widely studied and investigated by researchers from a variety of specializations. This book begins with the basic background of linear and nonlinear ring resonators. A novel design of nano device known as a PANDA ring resonator is proposed. The use of the device in the form of a PANDA in applications such as nanoelectronics, measurement, communication, sensors, optical and quantum computing, drug delivery, hybrid transistor and a new concept of electron-hole pair is discussed in detail.

  15. Laparoscopic appendicectomy using endo-ring applicator and fallope rings

    Directory of Open Access Journals (Sweden)

    Ali Iyoob

    2009-01-01

    Full Text Available Background/Aim: Wider adoption of laparoscopic appendicectomy (LA is limited by problems in securing the appendiceal base as well as the cost and the duration compared with the open procedure. The objective of this study was to assess the feasibility and efficacy of a new method for securing the appendiceal base in LA, so as to make the entire procedure simpler and cheaper, and hence, more popular. Methods: Twenty-five patients who were candidates for appendicectomy (emergency as well as elective and willing for the laparoscopic procedure were selected for this study. Ports used were 10 mm at the umbilicus, 5 mm at the lower right iliac fossa, and 10 mm at the left iliac fossa. Extremely friable, ruptured, or turgid organs of diameters larger than 8 mm were excluded from the study. The mesoappendix was divided close to the appendix by diathermy. Fallope rings were applied to the appendiceal base using a special ring applicator, and the appendix was divided and extracted through the lumen of the applicator. Results: The procedure was successful in 23 (92% cases, and the mean duration of the procedure was 20 minutes (15-32 minutes. There were no procedural complications seen during a median follow-up of two weeks. The equipment and rings were cheaper when compared with that of the standard methods of securing the base of the appendix. Conclusion: LA using fallope rings is a safe, simple, easy-to-learn, and economically viable method.

  16. ring i Praksis: Praksis i Læring

    DEFF Research Database (Denmark)

    Kjær, Malene

    2015-01-01

    I denne artiklen er empirien hentet fra et dansk sykehus der en sykepleiestudent skal gis tilgang til en bestemt fagkultur ved hjelp av den erfarne sykepleierens multimodale opplæringsform. I analysen vises, at ord, blikk, positur, berøring – alt inngår i en følsom samhandlingssituasjon der det o...

  17. A Experimental Study of Viscous Vortex Rings.

    Science.gov (United States)

    Dziedzic, Mauricio

    Motivated by the role played by vortex rings in the process of turbulent mixing, the work is focused on the problem of stability and viscous decay of a single vortex ring. A new classification is proposed for vortex rings which is based on extensive hot-wire measurements of velocity in the ring core and wake and flow visualization. Vortex rings can be classified as laminar, wavy, turbulence-producing, and turbulent. Prediction of vortex ring type is shown to be possible based on the vortex ring Reynolds number. Linear growth rates of ring diameter with time are observed for all types of vortex rings, with different growth rates occurring for laminar and turbulent vortex rings. Data on the viscous decay of vortex rings are used to provide experimental confirmation of the accuracy of Saffman's equation for the velocity of propagation of a vortex ring. Experimental data indicate that instability of the vortex ring strongly depends on the mode of generation and can be delayed by properly adjusting the generation parameters. A systematic review of the literature on vortex-ring interactions is presented in the form of an appendix, which helps identify areas in which further research may be fruitful.

  18. SELF-DUAL PERMUTATION CODES OVER FORMAL POWER SERIES RINGS AND FINITE PRINCIPAL IDEAL RINGS

    Institute of Scientific and Technical Information of China (English)

    张光辉; 刘宏伟

    2013-01-01

    In this paper, we study self-dual permutation codes over formal power series rings and finite principal ideal rings. We first give some results on the torsion codes associated with the linear codes over formal power series rings. These results allow for obtaining some conditions for non-existence of self-dual permutation codes over formal power series rings. Finally, we describe self-dual permutation codes over finite principal ideal rings by examining permutation codes over their component chain rings.

  19. Oscillatory persistent currents in quantum rings: Semiconductors versus superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Devreese, J.T., E-mail: jozef.devreese@ua.ac.b [TFVS, Universiteit Antwerpen, B-2020 Antwerpen (Belgium); COBRA, Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Fomin, V.M. [TFVS, Universiteit Antwerpen, B-2020 Antwerpen (Belgium); COBRA, Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Dept. of Theoretical Physics, State Univ. of Moldova, MD-2009 Chisinau (Moldova, Republic of); Institute for Integrative Nanosciences, IFW Dresden, D-01069 Dresden (Germany); Gladilin, V.N. [TFVS, Universiteit Antwerpen, B-2020 Antwerpen (Belgium); Dept. of Theoretical Physics, State Univ. of Moldova, MD-2009 Chisinau (Moldova, Republic of); Tempere, J. [TFVS, Universiteit Antwerpen, B-2020 Antwerpen (Belgium); Lyman Laboratory of Physics, Harvard University, Cambridge, MA 02138 (United States)

    2010-10-01

    Persistent currents are a hallmark of superconductivity in metals. To observe those dissipationless currents in a non-superconducting ring, the circumference of the ring must be short enough so that the phase coherence of the electronic wave functions is preserved around the loop. Recent progress in the fabrication of self-assembled semiconductor quantum rings (SAQRs), which can be filled with only a few (1-2) electrons, has offered the unique possibility to study the magnetic-field-induced oscillations in the persistent current carried by a single electron. In this paper, we discuss similarities and distinctions between the behavior of persistent currents in semiconductor and superconductor samples and give an overview of the recent results for oscillatory persistent currents in SAQRs. Although the real SAQR shape differs strongly from an idealized circular-symmetric open ring structure, the Aharonov-Bohm oscillations of the magnetization survive, as observed in low temperature magnetization measurements on In{sub x}Ga{sub 1-x}As/GaAs SAQRs.

  20. Ringing phenomenon in silica microspheres

    Institute of Scientific and Technical Information of China (English)

    Chunhua Dong; Changling Zou; Jinming Cui; Yong Yang; Zhengfu Han; Guangcan Guo

    2009-01-01

    Whispering gallery modes in silica microspheres are excited by a tunable continuous-wave laser through the fiber taper. Ringing phenomenon can be observed with high frequency sweeping speed. The thermal nonlinearity in the microsphere can enhance this phenomenon. Our measurement results agree very well with the theoretical predictions by the dynamic equation.

  1. Characteristic of Rings. Prime Fields

    Directory of Open Access Journals (Sweden)

    Schwarzweller Christoph

    2015-12-01

    Full Text Available The notion of the characteristic of rings and its basic properties are formalized [14], [39], [20]. Classification of prime fields in terms of isomorphisms with appropriate fields (ℚ or ℤ/p are presented. To facilitate reasonings within the field of rational numbers, values of numerators and denominators of basic operations over rationals are computed.

  2. The Lord of the Rings

    Institute of Scientific and Technical Information of China (English)

    潘金梅

    2002-01-01

    Peter Jackson's first film in The Lord of the Rings trilogy (三步曲) has just grabbed (夺得) four Oscars-awards for the best make-up, best cinematography (摄影), best visual effects and best original score.Chinese audience had a chance to watch the fihn from late April.

  3. Fusion rings and fusion ideals

    DEFF Research Database (Denmark)

    Andersen, Troels Bak

    by the so-called fusion ideals. The fusion rings of Wess-Zumino-Witten models have been widely studied and are well understood in terms of precise combinatorial descriptions and explicit generating sets of the fusion ideals. They also appear in another, more general, setting via tilting modules for quantum...

  4. E-læring

    DEFF Research Database (Denmark)

    Heilesen, Simon

    2001-01-01

    E-læring er et modeord og et mantra. Undervisning bliver ikke automatisk bedre af, at der sættes et ”e-” foran. Forbedring og fornyelse af undervisningen er betinget af, at vi forstår computermediets muligheder og skaber forandring ved at tilpasse det til de undervisningsformer, vi ønsker....

  5. Exercises in modules and rings

    CERN Document Server

    Lam, TY

    2009-01-01

    This volume offers a compendium of exercises of varying degree of difficulty in the theory of modules and rings. All exercises are solved in full detail. Each section begins with an introduction giving the general background and the theoretical basis for the problems that follow.

  6. Livslang læring

    DEFF Research Database (Denmark)

    Larson, Anne

    2016-01-01

    Pædagogisk sociologi beskæftiger sig blandt andet med de politiske rammebetingelser for opdragelse, undervisning, socialisering og uddannelse. I dette kapitel præsenteres en komparativ undersøgelse af EU’s politik med hensyn til livslang læring på den ene side, og den danske politik og lovgivning...

  7. Counting problems for number rings

    NARCIS (Netherlands)

    Brakenhoff, Johannes Franciscus

    2009-01-01

    In this thesis we look at three counting problems connected to orders in number fields. First we study the probability that for a random polynomial f in Z[X] the ring Z[X]/f is the maximal order in Q[X]/f. Connected to this is the probability that a random polynomial has a squarefree discriminant. T

  8. Near rings, fuzzy ideals, and graph theory

    CERN Document Server

    Satyanarayana, Bhavanari

    2013-01-01

    Near Rings, Fuzzy Ideals, and Graph Theory explores the relationship between near rings and fuzzy sets and between near rings and graph theory. It covers topics from recent literature along with several characterizations. After introducing all of the necessary fundamentals of algebraic systems, the book presents the essentials of near rings theory, relevant examples, notations, and simple theorems. It then describes the prime ideal concept in near rings, takes a rigorous approach to the dimension theory of N-groups, gives some detailed proofs of matrix near rings, and discusses the gamma near

  9. Cascaded uncoupled dual-ring modulator

    CERN Document Server

    Gu, Tingyi; Wong, Chee Wei; Dong, Po

    2014-01-01

    We demonstrate that by coherent driving two uncoupled rings in same direction, the effective photon circulating time in the dual ring modulator is reduced, with increased modulation quality. The inter-ring detuning dependent photon dynamics, Q-factor, extinction ratio and optical modulation amplitude of two cascaded silicon ring resonators are studied and compared with that of a single ring modulator. Experimentally measured eye diagrams, together with coupled mode theory simulations, demonstrate the enhancement of dual ring configuration at 20 Gbps with a Q ~ 20,000.

  10. High-Speed Ring Bus

    Science.gov (United States)

    Wysocky, Terry; Kopf, Edward, Jr.; Katanyoutananti, Sunant; Steiner, Carl; Balian, Harry

    2010-01-01

    The high-speed ring bus at the Jet Propulsion Laboratory (JPL) allows for future growth trends in spacecraft seen with future scientific missions. This innovation constitutes an enhancement of the 1393 bus as documented in the Institute of Electrical and Electronics Engineers (IEEE) 1393-1999 standard for a spaceborne fiber-optic data bus. It allows for high-bandwidth and time synchronization of all nodes on the ring. The JPL ring bus allows for interconnection of active units with autonomous operation and increased fault handling at high bandwidths. It minimizes the flight software interface with an intelligent physical layer design that has few states to manage as well as simplified testability. The design will soon be documented in the AS-1393 standard (Serial Hi-Rel Ring Network for Aerospace Applications). The framework is designed for "Class A" spacecraft operation and provides redundant data paths. It is based on "fault containment regions" and "redundant functional regions (RFR)" and has a method for allocating cables that completely supports the redundancy in spacecraft design, allowing for a complete RFR to fail. This design reduces the mass of the bus by incorporating both the Control Unit and the Data Unit in the same hardware. The standard uses ATM (asynchronous transfer mode) packets, standardized by ITU-T, ANSI, ETSI, and the ATM Forum. The IEEE-1393 standard uses the UNI form of the packet and provides no protection for the data portion of the cell. The JPL design adds optional formatting to this data portion. This design extends fault protection beyond that of the interconnect. This includes adding protection to the data portion that is contained within the Bus Interface Units (BIUs) and by adding to the signal interface between the Data Host and the JPL 1393 Ring Bus. Data transfer on the ring bus does not involve a master or initiator. Following bus protocol, any BIU may transmit data on the ring whenever it has data received from its host. There

  11. Unique Physician Identification Number (UPIN) Directory

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Unique Physician Identification Number (UPIN) Directory contains selected information on physicians, doctors of Osteopathy, limited licensed practitioners and...

  12. RING-APODIZED VORTEX CORONAGRAPHS FOR OBSCURED TELESCOPES. I. TRANSMISSIVE RING APODIZERS

    Energy Technology Data Exchange (ETDEWEB)

    Mawet, D. [European Southern Observatory, Alonso de Cordóva 3107 Vitacura, Santiago (Chile); Pueyo, L. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Carlotti, A. [Mechanical and Aerospace Engineering, Princeton University, Olden Street, Princeton, NJ 08544 (United States); Mennesson, B.; Serabyn, E.; Wallace, J. K. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)

    2013-11-01

    The vortex coronagraph (VC) is a new generation small inner working angle (IWA) coronagraph currently offered on various 8 m class ground-based telescopes. On these observing platforms, the current level of performance is not limited by the intrinsic properties of actual vortex devices, but by wavefront control residuals and incoherent background (e.g., thermal emission of the sky), or the light diffracted by the imprint of the secondary mirror and support structures on the telescope pupil. In the particular case of unfriendly apertures (mainly large central obscuration) when very high contrast is needed (e.g., direct imaging of older exoplanets with extremely large telescopes or space-based coronagraphs), a simple VC, like most coronagraphs, cannot deliver its nominal performance because of the contamination due to the diffraction from the obscured part of the pupil. Here, we propose a novel yet simple concept that circumvents this problem. We combine a vortex phase mask in the image plane of a high-contrast instrument with a single pupil-based amplitude ring apodizer, tailor-made to exploit the unique convolution properties of the VC at the Lyot-stop plane. We show that such a ring-apodized vortex coronagraph (RAVC) restores the perfect attenuation property of the VC regardless of the size of the central obscuration, and for any (even) topological charge of the vortex. More importantly, the RAVC maintains the IWA and conserves a fairly high throughput, which are signature properties of the VC.

  13. Quantum Unique Ergodicity for Eisenstein Series on the Hilbert Modular Group over a Totally Real Field

    DEFF Research Database (Denmark)

    Truelsen, Jimi Lee

    W. Luo and P. Sarnak have proved quantum unique ergodicity for Eisenstein series on $PSL(2,Z) \\backslash H$. We extend their result to Eisenstein series on $PSL(2,O) \\backslash H^n$, where $O$ is the ring of integers in a totally real field of degree $n$ over $Q$ with narrow class number one, using...... the Eisenstein series considered by I. Efrat. We also give an expository treatment of the theory of Hecke operators on non-holomorphic Hilbert modular forms....

  14. The Canarias Einstein Ring: a Newly Discovered Optical Einstein Ring

    CERN Document Server

    Bettinelli, Margherita; Aparicio, Antonio; Hidalgo, Sebastian L; Cassisi, Santi; Walker, Alistair R; Piotto, Giampaolo; Valdes, Frank

    2016-01-01

    We report the discovery of an optical Einstein Ring in the Sculptor constellation, IAC J010127-334319, in the vicinity of the Sculptor Dwarf Spheroidal Galaxy. It is an almost complete ring ($\\sim 300^{\\circ}$) with a diameter of $\\sim 4.5\\, {\\rm arcsec}$. The discovery was made serendipitously from inspecting Dark Energy Camera (DECam) archive imaging data. Confirmation of the object nature has been obtained by deriving spectroscopic redshifts for both components, lens and source, from observations at the $10.4$ m Gran Telescopio CANARIAS (GTC) with the spectrograph OSIRIS. The lens, a massive early-type galaxy, has a redshift of ${\\rm z}=0.581$ while the source is a starburst galaxy with redshift of ${\\rm z}=1.165$. The total enclosed mass that produces the lensing effect has been estimated to be ${\\rm M_{tot}=(1.86 \\pm 0.23) \\,\\cdot 10^{12}\\, {\\rm M_{\\odot}}}$.

  15. Measurement of sextupole orbit offsets in the APS storage ring.

    Energy Technology Data Exchange (ETDEWEB)

    Borland, M.

    1999-04-16

    Horizontal orbit errors at the sextuples in the Advanced Photon Source (APS) storage ring can cause changes in tune and modulation of the beta functions around the ring. To determine the significance of these effects requires knowing the orbit relative to the magnetic center of the sextuples. The method considered here to determine the horizontal beam position in a given sextupole is to measure the tune shift caused by a change in the sextupole strength. The tune shift and a beta function for the same plane uniquely determine the horizontal beam position in the sextupole. The beta function at the sextupole was determined by propagating the beta functions measured at nearby quadrupoles to the sextupole location. This method was used to measure the sextupole magnetic center offset relative to an adjacent beam position monitor (BPM) at a number of sextupole locations. We report on the successes and problems of the method as well as an improved method.

  16. Feasibility of beam crystallization in a cooler storage ring

    Directory of Open Access Journals (Sweden)

    Yosuke Yuri

    2005-11-01

    Full Text Available It has been known theoretically that a charged-particle beam circulating in a storage ring exhibits an “ordered” configuration at the space-charge limit. Such an ultimate state of matter is called a crystalline beam whose emittance is ideally equal to zero except for quantum noise. This paper discusses how close one can come to various ordered states by employing currently available accelerator technologies. The dynamic nature of ultracold beams and conditions required for crystallization are briefly reviewed. Molecular dynamics simulations are performed to study the feasibility of this unique phenomenon, considering practical situations in general cooling experiments. It is pointed out that several essential obstacles must be overcome to reach a three-dimensional crystalline state in a storage ring. Doppler laser cooling of ion beams is also numerically simulated to explore the possibility of beam crystallization in an existing machine.

  17. Stable rings generated by their units

    Directory of Open Access Journals (Sweden)

    Huanyin Chen

    2001-01-01

    Full Text Available We introduce the class of rings satisfying (m,1-stable range and investigate equivalent characterizations of such rings. These give generalizations of the corresponding results by Badawi (1994, Ehrlich (1976, and Fisher and Snider (1976.

  18. How to Remove a Stuck Ring Safely

    Science.gov (United States)

    ... Gardening Safety Turkey Carving Removing a Ring Español Artritis de la base del pulgar Dedo en gatillo ... Gardening Safety Turkey Carving Removing a Ring Español Artritis de la base del pulgar Dedo en gatillo ...

  19. On π-regularity of General Rings

    Institute of Scientific and Technical Information of China (English)

    CHEN WEI-XING; CUI SHU-YING

    2010-01-01

    A general ring means an associative ring with or without identity. An idempotent e in a general ring I is called left (right) semicentral if for every x∈ I,xe = exe (ex = exe). And I is called semiabelian ff every idempotent in I is left or right semicentral. It is proved that a semiabelian general ring I is π-regular if and only ff the set N(I) of nilpotent elements in I is an ideal of I and I/N(I) is regular. It follows that if I is a semiabelian general ring and K is an ideal of I,then I is π-regular if and only if both K and I/K are r-regular. Based on this we prove that every semiabelian GVNL-ring is an SGVNL-ring. These generalize several known results on the relevant subject. Furthermore we give a characterization of a semiabelian GVNL-ring.

  20. International Tree Ring Data Bank (ITRDB)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tree ring data from the International Tree Ring Data Bank and World Data Center for Paleoclimatology archives. Data include raw treering measurements (most are...

  1. Experiments with vortex rings in air

    Science.gov (United States)

    Hernández, R. H.; Cibert, B.; Béchet, C.

    2006-09-01

    We report quantitative experimental measurements of the instability of vortex rings generated in air. Vortex rings are created by pushing air through the circular orifice of a cylindrical cavity with a flat piston driven by a loudspeaker. Hot-wire anemometry provides accurate measurements of the velocity profile at all stages of the ring formation including stable and unstable rings. Flow visualization using a laser light sheet shows that the initially undisturbed vortex ring is progressively deformed in the azimuthal direction giving rise to a wavy azimuthal and periodic pattern in the circumference of the ring. The wavy pattern is steady, i.e., it does not rotate or translate during the ring's motion. However as the vortex motion progresses in the axial direction, the displaced portions of the ring are convected away from the initial undisturbed position and the wavy pattern grows with local Reynolds number.

  2. Persistent currents in normal metal rings.

    Science.gov (United States)

    Bluhm, Hendrik; Koshnick, Nicholas C; Bert, Julie A; Huber, Martin E; Moler, Kathryn A

    2009-04-03

    The authors have measured the magnetic response of 33 individual cold mesoscopic gold rings, one ring at a time. The response of some sufficiently small rings has a component that is periodic in the flux through the ring and is attributed to a persistent current. Its period is close to h/e, and its sign and amplitude vary between rings. The amplitude distribution agrees well with predictions for the typical h/e current in diffusive rings. The temperature dependence of the amplitude, measured for four rings, is also consistent with theory. These results disagree with previous measurements of three individual metal rings that showed a much larger periodic response than expected. The use of a scanning SQUID microscope enabled in situ measurements of the sensor background. A paramagnetic linear susceptibility and a poorly understood anomaly around a zero field are attributed to defect spins.

  3. Towards a theory for the Uranian rings

    Science.gov (United States)

    Goldreich, P.; Tremaine, S.

    1979-01-01

    Interparticle collisions, radiation drag, and differential precession all tend to disrupt the rings of Uranus. The first two effects lead to radial spreading which would disrupt a free ring in less than or approximately 100,000,000 yr. It is proposed that the rings are confined in radius by gravitational torques from a series of small satellites that orbit with the ring system. Differential precession tends to destroy the apse alignment of the elliptical epsilon ring. It is suggested that apse alignment is maintained by the self-gravity of the ring. The resulting mass of the epsilon ring is approximately 5 times 10 to the 18th power g. Its radial confinement requires (for example) a pair of satellites of mass approximately 10 to the 19th power g, in circular orbits roughly 500 km away on either side of the ring

  4. Kernel representations for behaviors over finite rings

    NARCIS (Netherlands)

    Kuijper, M.; Pinto, R.; Polderman, J.W.; Yamamoto, Y.

    2006-01-01

    In this paper we consider dynamical systems finite rings. The rings that we study are the integers modulo a power of a given prime. We study the theory of representations for such systems, in particular kernel representations.

  5. The Structure of gr-simple Rings

    Institute of Scientific and Technical Information of China (English)

    朱彬

    2003-01-01

    A characterization of gr-simple rings is given by using the notion of componentwise-dense subrings of a full matrix ring over a division ring. As a conse-quence, any G-graded full matrix ring over a division ring is isomorphic to a dense subring of a full matrix ring with a good G-grading. Some conditions for a grading of a full matrix ring to be isomorphic to a good one are given, which generalize some results in: Dáscáscu, S., Lon, B., Niǎstǎsescu, C. and Montes, J. R., Group gradingson full matrix rings, J. Algebra, 220(1999), 709-728.

  6. On Splitting Rings for Azumaya Skew Polynomial Rings

    Institute of Scientific and Technical Information of China (English)

    George Szeto; Lianyong Xue

    2001-01-01

    Let B be a ring with 1, p an automorphism of B of order n for some integer n, and B[x; p] the skew polynomial ring in x over B such that 1, x,x2,... ,xn-1 are independent over B and xn ∈ U(Bp), where Bp is the set of elements in B fixed under p and U(Bρ) is the set of all units in Bρ. Let -ρ be the inner automorphism of B[x; p] induced by x. Assume n is a unit in B. It is shown that, for a -ρ-Galois extension B[x; p] over (B[x; ρ])-ρ (resp., a DeMeyer-Kanzaki Galois extention B over Bp), B[x; ρ] is Azumaya if and only if (B[x; ρ])-ρ (resp.,B) is Azumaya, and some splitting rings of B[x; ρ], (B[x; ρ])-ρ and B coincide.

  7. Uniqueness of time-independent electromagnetic fields

    DEFF Research Database (Denmark)

    Karlsson, Per W.

    1974-01-01

    As a comment on a recent paper by Steele, a more general uniqueness theorem for time-independent fields is mentioned. ©1974 American Institute of Physics......As a comment on a recent paper by Steele, a more general uniqueness theorem for time-independent fields is mentioned. ©1974 American Institute of Physics...

  8. Some Graphs Containing Unique Hamiltonian Cycles

    Science.gov (United States)

    Lynch, Mark A. M.

    2002-01-01

    In this paper, two classes of graphs of arbitrary order are described which contain unique Hamiltonian cycles. All the graphs have mean vertex degree greater than one quarter the order of the graph. The Hamiltonian cycles are detailed, their uniqueness proved and simple rules for the construction of the adjacency matrix of the graphs are given.…

  9. Constructing Dense Graphs with Unique Hamiltonian Cycles

    Science.gov (United States)

    Lynch, Mark A. M.

    2012-01-01

    It is not difficult to construct dense graphs containing Hamiltonian cycles, but it is difficult to generate dense graphs that are guaranteed to contain a unique Hamiltonian cycle. This article presents an algorithm for generating arbitrarily large simple graphs containing "unique" Hamiltonian cycles. These graphs can be turned into dense graphs…

  10. 78 FR 58785 - Unique Device Identification System

    Science.gov (United States)

    2013-09-24

    ... 16, 801, 803, et al. Unique Device Identification System; Final Rule #0;#0;Federal Register / Vol. 78... 0910-AG31 Unique Device Identification System AGENCY: Food and Drug Administration, HHS. ACTION: Final... will substantially reduce existing obstacles to the adequate identification of medical devices used in...

  11. Small supernumerary marker chromosome and chromosome 18p abnormalities%编外标记染色体与18p染色体异常

    Institute of Scientific and Technical Information of China (English)

    刘玉鹏; 秦炯

    2016-01-01

    人类正常细胞核中有22对常染色体与1对性染色体,但一些人细胞核内另有多余的常染色体片段,被称为编外标记染色体(small supernumerary marker chromosome,sSMC).sSMC属于染色体结构异常,因其片段太小,并缺少明显的显带模式,无法通过传统的细胞遗传学显带技术进行识别,需要采用芯片比较基因组杂交或荧光原位杂交等多种分子生物学诊断方法才能确诊.由sSMC导致的染色体异常综合征较多,常见为Pallister-Killian综合征、等臂18p染色体综合征、猫眼综合征、Emanuel综合征.智力障碍人群中sSMC中发生率较高,临床缺乏特异性表现,随着分子细胞遗传学分析技术的提高,sSMC的识别率逐步提高.遗传咨询及产前诊断是减少sSMC发生的重要措施,分子生物学技术是明确sSMC的必要方法.现就sSMC相关18p染色体异常综合征的核型特点、发病机制、临床表现等进行综述.%Humans typically have 22 pairs of autosomal chromosomes in cells,and a pair of sex chromosomes.Some individuals have an extra,autosomal chromosome called a small supernumerary marker chromosome (sSMC).sSMC is a structurally abnormal chromosome fragment.The fragments are too small and no-specific banding pattern to be identified by conventional banding cytogenetic analysis.Array-based comparative genomic hybridization (aCGH),fluorescence in situ hybridization (FISH) or other molecular biological methods are necessary for the diagnosis.This article summarized the karyotype,pathogenesis,and the clinical manifestations of the sSMC-related chromosome 18p abnormalities.The patients with sSMC usually presented with abnormal chromosome syndrome.Some syndromes are relative common,such as Pallister-Killian syndrome,isochromosome 18p syndrome,Cat eye syndromes or Emanuel syndrome.sSMC is considered to be the frequent cause of mental retardation.The patients have no specific symptoms.With the progress of molecular cytogenetics

  12. Nonlinear analysis of ring oscillator circuits

    KAUST Repository

    Ge, Xiaoqing

    2010-06-01

    Using nonlinear systems techniques, we analyze the stability properties and synchronization conditions for ring oscillator circuits, which are essential building blocks in digital systems. By making use of its cyclic structure, we investigate local and global stability properties of an n-stage ring oscillator. We present a sufficient condition for global asymptotic stability of the origin and obtain necessity if the ring oscillator consists of identical inverter elements. We then give a synchronization condition for identical interconnected ring oscillators.

  13. Dysphagia due to Multiple Esophageal Rings

    Directory of Open Access Journals (Sweden)

    Stephen N Sullivan

    1995-01-01

    Full Text Available A 27-year-old Saudi man with dysphagia due to multiple esophageal rings is reported and the literature reviewed. Dysphagia due to multiple esophageal rings is very rare. Only 15 cases have been reported. The patient is usually male and has had dysphagia for many years when presenting. The cause of the rings is unknown. Theories to explain dysphagia are that the rings are either congenital or an unusual manifestation of gastroesophageal reflux.

  14. Polar ring galaxies formation and properties

    CERN Document Server

    Bournaud, F; Bournaud, Frederic; Combes, Francoise

    2003-01-01

    Formation scenarios for polar ring galaxies are studied through N-body simulatio ns that are compared with existing observations. It is shown that polar rings ar e likely to be formed by tidal accretion of the polar material from a gas rich d onor galaxy. The distribution of dark matter in polar ring galaxies is studied: dark halos seem to be flattened towards the polar rings.

  15. Double hexagonal graphene ring synthesized using a growth-etching method

    Science.gov (United States)

    Liu, Jinyang; Xu, Yangyang; Cai, Hongbing; Zuo, Chuandong; Huang, Zhigao; Lin, Limei; Guo, Xiaomin; Chen, Zhendong; Lai, Fachun

    2016-07-01

    Precisely controlling the layer number, stacking order, edge configuration, shape and structure of graphene is extremely challenging but highly desirable in scientific research. In this report, a new concept named the growth-etching method has been explored to synthesize a graphene ring using the chemical vapor deposition process. The graphene ring is a hexagonal structure, which contains a hexagonal exterior edge and a hexagonal hole in the centre region. The most important concept introduced here is that the oxide nanoparticle derived from annealing is found to play a dual role. Firstly, it acts as a nucleation site to grow the hexagonal graphene domain and then it works as a defect for etching to form a hole. The evolution process of the graphene ring with the etching time was carefully studied. In addition, a double hexagonal graphene ring was successfully synthesized for the first time by repeating the growth-etching process, which not only confirms the validity and repeatability of the method developed here but may also be further extended to grow unique graphene nanostructures with three, four, or even tens of graphene rings. Finally, a schematic model was drawn to illustrate how the double hexagonal graphene ring is generated and propagated. The results shown here may provide valuable guidance for the design and growth of unique nanostructures of graphene and other two-dimensional materials.

  16. Generalized periodic and generalized Boolean rings

    Directory of Open Access Journals (Sweden)

    Howard E. Bell

    2001-01-01

    Full Text Available We prove that a generalized periodic, as well as a generalized Boolean, ring is either commutative or periodic. We also prove that a generalized Boolean ring with central idempotents must be nil or commutative. We further consider conditions which imply the commutativity of a generalized periodic, or a generalized Boolean, ring.

  17. A Ring Construction Using Finite Directed Graphs

    Science.gov (United States)

    Bardzell, Michael

    2012-01-01

    In this paper we discuss an interesting class of noncommutative rings which can be constructed using finite directed graphs. This construction also creates a vector space. These structures provide undergraduate students connections between ring theory and graph theory and, among other things, allow them to see a ring unity element that looks quite…

  18. IAG ring test animal proteins 2013

    NARCIS (Netherlands)

    Raamsdonk, van L.W.D.; Pinckaers, V.G.Z.; Scholtens-Toma, I.M.J.; Prins, T.W.; Vliege, J.J.M.

    2013-01-01

    A ring test was organized for the detection of animal proteins in animal feed by microscopy in the framework of the annual ring tests of the IAG - International Association for Feeding stuff Analysis, Section Feeding stuff Microscopy. The organizer of the the ring study was to provide the

  19. RRF Rings which are not LRF

    Indian Academy of Sciences (India)

    K Varadarajan

    2000-05-01

    Define a ring to be RRF (respectively LRF) if every right (respectively left) -module is residually finite. We determine the necessary and sufficient conditions for a formal triangular matrix ring $$T=\\begin{pmatrix}A & 0\\\\ M & B\\end{pmatrix}$$ to be RRF (respectively LRF). Using this we give examples of RRF rings which are not LRF.

  20. Familial transmission of a ring chromosome 21

    DEFF Research Database (Denmark)

    Hertz, Jens Michael

    1987-01-01

    A ring chromosome 21 was found in a phenotypically normal mother and her son. The clinical findings in the son were bilateral retention of the testes and a slightly delayed puberty onset. Consequences of a ring formation of a chromosome 21 in phenotypically normal patients are presented...... and discussed, and the previously reported cases of familially transmitted G-group ring chromosomes are reviewed....