R.A. Kumar (Ravinesh); D.T. Pilz (Daniela); T.D. Babatz (Timothy); T.D. Cushion (Thomas); K. Harvey (Kirsten); M. Topf (Maya); L. Yates (Laura); S. Robb (Stephanie); G. Uyanik (Gökhan); G.M.S. Mancini (Grazia); M.I. Rees (Mark); R.J. Harvey (Robert); W.B. Dobyns (William)
2010-01-01
textabstracte previously showed that mutations in LIS1 and DCX account for ~85% of patients with the classic form of lissencephaly (LIS). Some rare forms of LIS are associated with a disproportionately small cerebellum, referred to as lissencephaly with cerebellar hypoplasia (LCH). Tubulin alpha1A
Jang, Mi-Ae; Woo, Hye In; Kim, Jong-Won; Lee, Jeehun; Ki, Chang-Seok
2013-05-01
Malformations of cortical development include a wide range of brain developmental anomalies that commonly lead to developmental delay and epilepsy. Lissencephaly and subcortical band heterotopia are major malformations of cortical development due to abnormal neuronal migration and several genes have been identified including ARX, DCX, LIS1, RELN, TUBA1A, and VLDLR. Traditionally, genetic testing for lissencephaly and subcortical band heterotopia has been done in the order of the probability of detection of mutation according to the radiologic features, but the success rate could be variable with this time-consuming approach. In this study we used whole-exome sequencing to identify mutations in a 5-year-old girl with lissencephaly spectrum with subcortical band heterotopia. After excluding lissencephaly-related genes, one deleterious mutation (NM_178153.2:c.665C > T, p.Thr222Ile) in the DCX gene was identified. Further Sanger sequencing validated the variant in the patient but not in both parents indicating a de novo mutation. The present report demonstrates that whole-exome sequencing may be a useful tool for the identification of mutations in patients with lissencephaly and subcortical band heterotopias as well as malformations of cortical development. Copyright © 2013 Elsevier Inc. All rights reserved.
Bahi-Buisson, Nadia; Souville, Isabelle; Fourniol, Franck J; Toussaint, Aurelie; Moores, Carolyn A; Houdusse, Anne; Lemaitre, Jean Yves; Poirier, Karine; Khalaf-Nazzal, Reham; Hully, Marie; Leger, Pierre Louis; Elie, Caroline; Boddaert, Nathalie; Beldjord, Cherif; Chelly, Jamel; Francis, Fiona
2013-01-01
X-linked isolated lissencephaly sequence and subcortical band heterotopia are allelic human disorders associated with mutations of doublecortin (DCX), giving both familial and sporadic forms. DCX encodes a microtubule-associated protein involved in neuronal migration during brain development. Structural data show that mutations can fall either in surface residues, likely to impair partner interactions, or in buried residues, likely to impair protein stability. Despite the progress in understanding the molecular basis of these disorders, the prognosis value of the location and impact of individual DCX mutations has largely remained unclear. To clarify this point, we investigated a cohort of 180 patients who were referred with the agyria-pachygyria subcortical band heterotopia spectrum. DCX mutations were identified in 136 individuals. Analysis of the parents' DNA revealed the de novo occurrence of DCX mutations in 76 cases [62 of 70 females screened (88.5%) and 14 of 60 males screened (23%)], whereas in the remaining cases, mutations were inherited from asymptomatic (n = 14) or symptomatic mothers (n = 11). This represents 100% of families screened. Female patients with DCX mutation demonstrated three degrees of clinical-radiological severity: a severe form with a thick band (n = 54), a milder form (n = 24) with either an anterior thin or an intermediate thickness band and asymptomatic carrier females (n = 14) with normal magnetic resonance imaging results. A higher proportion of nonsense and frameshift mutations were identified in patients with de novo mutations. An analysis of predicted effects of missense mutations showed that those destabilizing the structure of the protein were often associated with more severe phenotypes. We identified several severe- and mild-effect mutations affecting surface residues and observed that the substituted amino acid is also critical in determining severity. Recurrent mutations representing 34.5% of all DCX mutations often lead
Bahi-Buisson, Nadia; Souville, Isabelle; Fourniol, Franck?J.; Toussaint, Aurelie; Moores, Carolyn A.; Houdusse, Anne; Yves Lemaitre, Jean; Poirier, Karine; Khalaf-Nazzal, Reham; Hully, Marie; Louis Leger, Pierre; Elie, Caroline; Boddaert, Nathalie; Beldjord, Cherif; Chelly, Jamel
2013-01-01
X-linked isolated lissencephaly sequence and subcortical band heterotopia are allelic human disorders associated with mutations of doublecortin (DCX), giving both familial and sporadic forms. DCX encodes a microtubule-associated protein involved in neuronal migration during brain development. Structural data show that mutations can fall either in surface residues, likely to impair partner interactions, or in buried residues, likely to impair protein stability. Despite the progress in understa...
Lissencephaly: Expanded imaging and clinical classification.
Di Donato, Nataliya; Chiari, Sara; Mirzaa, Ghayda M; Aldinger, Kimberly; Parrini, Elena; Olds, Carissa; Barkovich, A James; Guerrini, Renzo; Dobyns, William B
2017-06-01
Lissencephaly ("smooth brain," LIS) is a malformation of cortical development associated with deficient neuronal migration and abnormal formation of cerebral convolutions or gyri. The LIS spectrum includes agyria, pachygyria, and subcortical band heterotopia. Our first classification of LIS and subcortical band heterotopia (SBH) was developed to distinguish between the first two genetic causes of LIS-LIS1 (PAFAH1B1) and DCX. However, progress in molecular genetics has led to identification of 19 LIS-associated genes, leaving the existing classification system insufficient to distinguish the increasingly diverse patterns of LIS. To address this challenge, we reviewed clinical, imaging and molecular data on 188 patients with LIS-SBH ascertained during the last 5 years, and reviewed selected archival data on another ∼1,400 patients. Using these data plus published reports, we constructed a new imaging based classification system with 21 recognizable patterns that reliably predict the most likely causative genes. These patterns do not correlate consistently with the clinical outcome, leading us to also develop a new scale useful for predicting clinical severity and outcome. Taken together, our work provides new tools that should prove useful for clinical management and genetic counselling of patients with LIS-SBH (imaging and severity based classifications), and guidance for prioritizing and interpreting genetic testing results (imaging based- classification). © 2017 Wiley Periodicals, Inc.
Genetics Home Reference: isolated lissencephaly sequence
... Home Health Conditions Isolated lissencephaly sequence Isolated lissencephaly sequence Printable PDF Open All Close All Enable Javascript ... view the expand/collapse boxes. Description Isolated lissencephaly sequence (ILS) is a condition that affects brain development ...
Lissencephaly and band heterotopia: LIS1, TUBA1A, and DCX mutations in Hungary.
Mokánszki, Attila; Körhegyi, Ivett; Szabó, Nóra; Bereg, Edit; Gergev, Gyurgyinka; Balogh, Erzsébet; Bessenyei, Beáta; Sümegi, Andrea; Morris-Rosendahl, Deborah J; Sztriha, László; Oláh, Eva
2012-12-01
The spectrum of lissencephaly ranges from absent (agyria) or decreased (pachygyria) convolutions to less severe malformation known as subcortical band heterotopia. Mutations involving LIS1 and TUBA1A result in the classic form of lissencephaly, whereas mutations of the DCX gene cause lissencephaly in males and subcortical band heterotopia in females. This report describes the clinical manifestations and imaging and genetic findings in 2 boys with lissencephaly and a girl with subcortical band heterotopia. An ovel mutation (c.83_84delAT, p.Tyr28Phefs*31) was identified in LIS1 in 1 of the boys with lissencephaly and another novel mutation (c.200delG, p.Ile68Leufs*87) was found in DCX in the girl with subcortical band heterotopia. The mutations appeared in the first half of the genes and are predicted to result in truncated proteins. A mutation was found in the TUBA1A gene (c.1205G>A, p.Arg402His) in the other boy. This mutation affects the folding of tubulin heterodimers, changing the interactions with proteins that bind microtubules.
Genotypically defined lissencephalies show distinct pathologies.
Forman, Mark S; Squier, Waney; Dobyns, William B; Golden, Jeffrey A
2005-10-01
Lissencephaly is traditionally divided into 2 distinct pathologic forms: classic (type I) and cobblestone (type II). To date, mutations in 4 genes, LIS1, DCX, RELN, and ARX, have been associated with distinct type I lissencephaly syndromes. Each of these genes has been shown to play a role in normal cell migration, consistent with the presumed pathogenesis of type I lissencephaly. Based on these data, we hypothesized that all forms of radiographically defined type I lissencephaly independent of genotype would be pathologically similar. To test this hypothesis, we examined brains from 16 patients, including 15 lissencephalic patients and one patient with subcortical band heterotopia. Of these 16 patients, 6 had LIS1 deletions, 2 had DCX mutations, and 2 had ARX mutations. In addition, 6 patients had no defined genetic defect, although the patient with subcortical band heterotopia exhibited the same pattern of malformation expected with an XLIS mutation. In all cases, the cortex was thickened; however, the topographic distribution of the cortical pathology varied, ranging from frontal- to occipital-biased pathology to diffuse involvement of the neocortex. Although brains with LIS1 deletions exhibited the classic 4-layer lissencephalic architecture, patients with DCX and ARX mutations each had unique cytoarchitectural findings distinct from LIS1. Furthermore, 2 of the 5 patients with no known genetic defect showed a fourth type of histopathology characterized by a 2-layered cortex. Interestingly, the 2 brains with the fourth type of lissencephaly showed profound brainstem and cerebellar abnormalities. In summary, we identified at least 4 distinct histopathologic subtypes of lissencephaly that stratify with the underlying genetic defect. Based on these data, a new classification for lissencephaly is proposed that incorporates both pathologic and genetic findings.
Midbrain and Hindbrain Involvement in Lissencephaly
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J Gordon Millichap
2009-02-01
Full Text Available Involvement of the midbrain and hindbrain (MHB in the various groups of lissencephalies was examined in an MRI study of 111 patients (aged 1 day to 32 years; mean 5 years 4 months studied at University of California San Francisco, and centers in France, Belgium, and Turkey.
The location of DCX mutations predicts malformation severity in X-linked lissencephaly.
Leger, Pierre-Louis; Souville, Isabelle; Boddaert, Nathalie; Elie, Caroline; Pinard, Jean Marc; Plouin, Perrine; Moutard, Marie Laure; des Portes, Vincent; Van Esch, Hilde; Joriot, Sylvie; Renard, Jean Louis; Chelly, Jamel; Francis, Fiona; Beldjord, Cherif; Bahi-Buisson, Nadia
2008-10-01
Lissencephaly spectrum (LIS) is one of the most severe neuronal migration disorders that ranges from agyria/pachygyria to subcortical band heterotopia. Approximately 80% of patients with the LIS spectrum carry mutations in either the LIS1 or DCX (doublecortin) genes which have an opposite gradient of severity. The aim of the study was to evaluate in detail the phenotype of DCX-associated lissencephaly and to look for genotype-phenotype correlations. Of the 180 male patients with DCX-related lissencephaly, 33 males (24 familial cases and nine cases with de novo mutations) were found with hemizygous DCX mutations and were clinically and genetically assessed here. DCX mutation analysis revealed that the majority of mutations were missense (79.2%), clustered in the two evolutionary conserved domains, N-DC and C-DC, of DCX. The most prominent radiological phenotype was an anteriorly predominant pachygyria or agyria (54.5%) although DCX-associated lissencephaly encompasses a complete range of LIS grades. The severity of neurological impairment was in accordance with the degree of agyria with severe cognitive impairment in all patients, inability to walk independently in over half and refractory epilepsy in more than a third. For genotype-phenotype correlations, patients were divided in two groups according to the location of DCX missense mutations. Patients with mutations in the C-DC domain tended to have a less severe lissencephaly (grade 4-5 in 58.3%) compared with those in the N-DC domain (grade 4-5 in 36.3%) although, in this dataset, this was not statistically significant (p = 0.12). Our evaluation suggests a putative correlation between phenotype and genotype. These data provide further clues to deepen our understanding of the function of the DCX protein and may give new insights into the molecular mechanisms that could influence the consequence of the mutation in the N-DC versus the C-DC domain of DCX.
A case of TUBA1A mutation presenting with lissencephaly and Hirschsprung disease.
Hikita, Norikatsu; Hattori, Hideji; Kato, Mitsuhiro; Sakuma, Satoru; Morotomi, Yoshiki; Ishida, Hiroshi; Seto, Toshiyuki; Tanaka, Katsuji; Shimono, Taro; Shintaku, Haruo; Tokuhara, Daisuke
2014-02-01
Gene mutation of tubulin alpha-1A (TUBA1A), a critical component of microtubules of the cytoskeleton, impairs neural migration and causes lissencephaly (LIS). The approximately 45 cases of disease-associated TUBA1A mutations reported to date demonstrate a wide spectrum of phenotypes. Here we describe an 8-year-old girl with lissencephaly, microcephaly, and early-onset epileptic seizures associated with a novel mutation in the TUBA1A gene. The patient developed Hirschsprung disease and the syndrome of inappropriate antidiuretic hormone secretion (SIADH), which had not previously been described in TUBA1A mutation-associated disease. Our case provides new insight into the wide spectrum of disease phenotypes associated with TUBA1A mutation. Copyright © 2013 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.
DEFF Research Database (Denmark)
Pedersen, Lotte B; Rompolas, Panteleimon; Christensen, Søren T
2007-01-01
Lissencephaly is a developmental brain disorder characterized by a smooth cerebral surface, thickened cortex and misplaced neurons. Classical lissencephaly is caused by mutations in LIS1, which encodes a WD-repeat protein involved in cytoplasmic dynein regulation, mitosis and nuclear migration....... Biochemical experiments confirmed that CrLis1 associates with outer dynein arm components and revealed that CrLis1 binds directly to rat NudC. Our results suggest that Lis1 and NudC are present in cilia and flagella and may regulate outer dynein arm activity....
Tian, Guoling; Cristancho, Ana G; Dubbs, Holly A; Liu, Grant T; Cowan, Nicholas J; Goldberg, Ethan M
2016-11-01
Microtubules are dynamic polymers of α/β tubulin heterodimers that play a critical role in cerebral cortical development, by regulating neuronal migration, differentiation, and morphogenesis. Mutations in genes that encode either α- or β-tubulin or a spectrum of proteins involved in the regulation of microtubule dynamics lead to clinically devastating malformations of cortical development, including lissencephaly. This is a single case report or a patient with lissencephaly, developmental delay, nystagmus, persistent hyperplastic primary vitreous, and infantile spasms, and undertook a neurogenetic workup. We include studies of mutant function in Escherichia coli and HeLa cells. The patient was found to have a novel de novo mutation in kinesin family member 2A (KIF2A). This mutation results in a substitution of isoleucine at a highly conserved threonine residue within the ATP-binding domain. The KIF2A p.Thr320Ile mutant protein exhibited abnormal solubility, and KIF2A p.Thr320Ile overexpression in cultured cells led to the formation of aberrant microtubule networks. Findings support the pathogenic link between KIF2A mutation and lissencephaly, and expand the range of presentation to include infantile spasms and congenital anomalies.
Lissencephaly and subcortical band heterotopia: molecular basis and diagnosis.
Leventer, R J; Pilz, D T; Matsumoto, N; Ledbetter, D H; Dobyns, W B
2000-07-01
Magnetic resonance imaging is now used routinely in the evaluation of developmental and neurological disorders and provides exquisite images of the living human brain. Consequently, it is evident that cortical malformations are more common than previously thought. Among the most severe is classical lissencephaly, in which the cortex lacks the complex folding that characterizes the normal human brain. Lissencephaly includes agyria and pachygyria, and merges with subcortical band heterotopia. Current molecular genetic techniques combined with the identification of affected patients have enabled the detection of two of the genes responsible: LIS1 (PAFAH1B1) on chromosome 17 and DCX (doublecortin) on the X chromosome. This review highlights the discovery of these genes and discusses the advances made in understanding the molecular basis of cortical development and improvements in diagnosis and genetic counseling.
Aigner, L; Fluegel, D; Dietrich, J; Ploetz, S; Winkler, J
2000-08-01
Isolated Lissencephaly Sequence (ILS) and Double-Cortex Syndrome (DC) are neuronal heterotopias caused by developmental defects in neuronal precursor cell migration. We report on the clinical and genetic assessment of a German pedigree with DCIILS. Affected males showed clinical symptoms typical of lissencephaly, i.e. seizures, severe mental retardation and extensive physical disability starting in the early postnatal period. Females, however, displayed a milder phenotype with epileptic seizures being the only clinical symptom of note. The MR imaging of a male ILS patient showed a smooth cortex with pachygyria, hydrocephalus and a diffuse, broad distribution of grey matter throughout the brain. In the affected female, a double cortex syndrome in the form of a subcortical bilateral band of grey matter was evident by MR imaging. The molecular and genetic basis of DC/ILS is associated with mutations in the X-linked doublecortin gene (DCX). The genetic assessment of the family revealed a novel missense mutation 211 G-->T in DCX exon 2 in affected family members. This mutation cosegregated with the clinical symptoms and resulted in a non-conservative amino acid substitution A71S. DCX is a microtubule-associated phosphoprotein and mutations in DCX might affect cytoskeletal dynamics and the regulation of cell migration.
Shimojima, Keiko; Okumura, Akihisa; Hayashi, Masaharu; Kondo, Takayuki; Inoue, Haruhisa; Yamamoto, Toshiyuki
2015-10-01
The human cerebral cortex is peculiar for a six-layered cellular-sheet structure with convolution, which is a consequence of neuronal migration. Dysfunctions of the pathways contributing to this mechanism typically lead to lissencephaly manifesting smooth brain surfaces. To investigate the unknown mechanism underlying neuronal migration disorders, we generated induced pluripotent stem (iPS) cells from two patients with lissencephaly. Whole gene expression study for iPS cells derived from a patient with a LIS1 deletion showed reduced expression of the coiled-coil-helix-coiled-coil-helix domain containing 2 gene (CHCHD2), which was also confirmed in iPS cells derived from a patient with a TUBA1A mutation. CHCHD2 expression was detected in neuronal cells differentiated from normal iPS cells in a time-dependent manner, as well as in the brain of a fetus at 26-28 week gestational age, suggesting development-dependent expression. Migrating neuronal cells showed CHCHD2 expression, suggesting its functional relevance to neuronal migration. Copyright © 2015 Elsevier Inc. All rights reserved.
Leventer, Richard Jacob
2005-04-01
Lissencephaly and subcortical band heterotopia are closely related cortical malformations and are true disorders of neuronal migration. The genetic basis of approximately 70% of classic lissencephaly and 80% of typical subcortical band heterotopia is known. Most are due to abnormalities within the LIS1 or DCX genes, with abnormalities ranging from single basepair substitutions to contiguous gene deletions. Understanding the genetic basis of these disorders has led to the elucidation of the molecular and developmental mechanisms that are adversely affected. There is a robust correlation between many of the clinical aspects of lissencephaly or subcortical band heterotopia and the type and location of mutations in the affected gene. Using this knowledge, the clinician can predict with some accuracy which gene is likely to be affected based on the clinical and imaging features. This review answers some of the key questions regarding the genotype-phenotype correlation for lissencephaly and subcortical band heterotopia.
Classical lissencephaly and double cortex (subcortical band heterotopia): LIS1 and doublecortin.
Gleeson, J G
2000-04-01
Classical lissencephaly and double cortex are genetic neuronal migration disorders associated with mental retardation and epilepsy. In classical lissencephaly, the six-layered cortex is replaced by a four layered structure lacking normal gyri or sulci. In double cortex, a second layer of cortical neurons underlies a normal cortex. A mutation in LIS1 or doublecortin can lead to either classical lissencephaly or double cortex, but because LIS1 is autosomal and doublecortin is X-linked (on the X chromosome), the disease inheritance pattern and risk of recurrence for the two genes are distinct. Mutation analysis for LIS1 and doublecortin is essential in determining the etiology of the disease in patients and may be helpful in determining the recurrence risk in families.
[Subcortical laminal heterotopia and lissencephaly: cerebral malformations of X-linked inheritance].
Pinard, J M; Desguerre, I; Motte, J; Dulac, O; Ponsot, G
1995-03-01
Subcortical laminar heterotopia (band heterotopia) is a brain malformation now recognized by MRI. We report 3 families (2 previously described) in which several members had subcortical laminar heterotopia or a more severe malformation (agyria/pachygyria). In these families, subcortical laminar heterotopia were observed in women and were associated with epilepsy or slight mental retardation depending on the extend of heterotopia. Males had lissencephaly with refractory epilepsy and severe mental retardation. The pedigrees of these families demonstrate that these 2 malformations originate from a single genetic origin. A single X-linked dominant gene is postulated. Diagnosis of subcortical laminar heterotopia in a female or lissencephaly in a male (except in the case of Miller-Dieker syndrome) requires appropriate genetic counselling in the family: brain imaging should be performed in relatives.
Mutation screening in a cohort of patients with lissencephaly and subcortical band heterotopia.
Torres, F R; Montenegro, M A; Marques-De-Faria, A P; Guerreiro, M M; Cendes, F; Lopes-Cendes, I
2004-03-09
The authors describe clinical, neuroimaging and molecular findings in a group of 15 patients with classic lissencephaly (LIS) and subcortical band heterotopia (SBH). A 1385A-->C mutation was found in the LIS1 gene in one patient with LIS more severe than expected for individuals with missense mutations in LIS1. The authors believe that the site of the mutation, present in a functionally critical region of the protein, could explain the unusual severe phenotype found in this patient.
Mutation screening in a cohort of patients with lissencephaly and subcortical band heterotopia
Torres, FR; Montenegro, MA; Marques-de-Faria, AP; Guerreiro, MM; Cendes, F.; Lopes-Cendes, I
2004-01-01
The authors describe clinical, neuroimaging and molecular findings in a group of 15 patients with classic lissencephaly ( LIS) and subcortical band heterotopia (SBH). A 1385A-->C mutation was found in the LIS1 gene in one patient with LIS more severe than expected for individuals with missense mutations in LIS1. The authors believe that the site of the mutation, present in a functionally critical region of the protein, could explain the unusual severe phenotype found in this patient.
Novel DCX mutation-caused lissencephaly in a boy and very mild heterotopia in his mother.
Takeshita, Satoru; Higuchi, Machiko; Suyama, Megumi; Koide, Wakato; Maki, Kanemasa; Ushijima, Katsumi; Ban, Kyoko; Saito, Mariko; Kato, Mitsuhiro; Saitoh, Shinji
2015-04-01
We describe a novel mutation in DCX in a family in which a proband boy had classical lissencephaly and his mother had extremely mild subcortical band heterotopia. No factors that would make the mother's symptoms milder, such as somatic mosaicism or skewed X chromosome inactivation, were observed. From this family, we conclude that a DCX mutation causes a pleiotropic phenotype in the female even if X chromosome inactivation pattern is not skewed, and the novel missense mutation in DCX produced relatively mild dysfunction of the doublecortin protein. © 2015 Japan Pediatric Society.
Tsai, Meng-Han; Kuo, Pei-Wen; Myers, Candace T; Li, Shih-Wen; Lin, Wei-Che; Fu, Ting-Ying; Chang, Hsin-Yun; Mefford, Heather C; Chang, Yao-Chung; Tsai, Jin-Wu
2016-09-01
To study the genetics and functional alteration of a family with X-linked lissencephaly and subcortical band heterotopia. Five affected patients (one male with lissencephaly, four female with subcortical band heterotopia) and their relatives were studied. Sanger sequencing of DCX gene, allele specific PCR and molecular inversion probe technique were performed. Mutant and wild type of the gene products, namely doublecortin, were expressed in cells followed by immunostaining to explore the localization of doublecortin and microtubules in cells. In vitro microtubule-binding protein spin-down assay was performed to quantify the binding ability of doublecortin to microtubules. We identified a novel DCX mutation c.785A > G, p.Asp262Gly that segregated with the affected members of the family. Allele specific PCR and molecular inversion probe technique demonstrated that the asymptomatic female carrier had an 8% mutant allele fraction in DNA derived from peripheral leukocytes. This mother had 7 children, 4 of whom were affected and all four affected siblings carried the mutation. Functional study showed that the mutant doublecortin protein had a significant reduction of its ability to bind microtubules. Low level mosaicism could be a cause of inherited risk from asymptomatic parents for DCX related lissencephaly-subcortical band heterotopia spectrum. This is particularly important in terms of genetic counselling for recurrent risk of future pregnancies. The reduced binding affinity of mutant doublecortin may contribute to developmental malformation of the cerebral cortex. Copyright © 2016 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.
Morris-Rosendahl, D.J.; Najm, J.; Lachmeijer, A.M.A.; Sztriha, L.; Martins, M.; Kuechler, A.; Haug, V.; Zeschnigk, C.; Martin, P.; Santos, M.; Vasconcelos, C.; Omran, H.; Kraus, U.; van der Knaap, M.S.; Schuierer, G.; Kutsche, K.; Uyanik, G.
2008-01-01
Mutations in the α-1a Tubulin (TUBA1A) gene have recently been found to cause cortical malformations resemblant of classical lissencephaly but with a specific combination of features. To date, TUBA1A mutations have been described in five patients and three foetuses. Our aims were to establish how
X-Linked Lissencephaly With Absent Corpus Callosum and Abnormal Genitalia
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David Coman FRACP
2017-11-01
Full Text Available X-linked lissencephaly with abnormal genitalia is a rare and devastating syndrome. The authors present an infant with a multisystem phenotype where the intestinal manifestations were as life limiting as the central nervous system features. Severe chronic diarrhea resulted in failure to thrive, dehydration, electrolyte derangements, long-term hospitalization, and prompted transition to palliative care. Other multisystem manifestations included megacolon, colitis, pancreatic insufficiency hypothalamic dysfunction, hypothyroidism, and hypophosphatasia. A novel aristaless-related homeobox gene mutation, c.1136G>T/p.R379L, was identified. This case contributes to the clinical, histological, and molecular understanding of the multisystem nature of this disorder, especially the role of ARX in the development of the enteroendocrine system.
DEFF Research Database (Denmark)
Høgfeldt Hansen, Leif
2016-01-01
The publication functions as a proces description of the development and construction of an urban furniture SPECTRUM in the city of Gwangju, Republic of Korea. It is used as the cataloque for the exhibition of Spectrum.......The publication functions as a proces description of the development and construction of an urban furniture SPECTRUM in the city of Gwangju, Republic of Korea. It is used as the cataloque for the exhibition of Spectrum....
des Portes, V; Pinard, J M; Billuart, P; Vinet, M C; Koulakoff, A; Carrié, A; Gelot, A; Dupuis, E; Motte, J; Berwald-Netter, Y; Catala, M; Kahn, A; Beldjord, C; Chelly, J
1998-01-09
X-SCLH/LIS syndrome is a neuronal migration disorder with disruption of the six-layered neocortex. It consists of subcortical laminar heterotopia (SCLH, band heterotopia, or double cortex) in females and lissencephaly (LIS) in males, leading to epilepsy and cognitive impairment. We report the characterization of a novel CNS gene encoding a 40 kDa predicted protein that we named Doublecortin and the identification of mutations in four unrelated X-SCLH/LIS cases. The predicted protein shares significant homology with the N-terminal segment of a protein containing a protein kinase domain at its C-terminal part. This novel gene is highly expressed during brain development, mainly in fetal neurons including precursors. The complete disorganization observed in lissencephaly and heterotopia thus seems to reflect a failure of early events associated with neuron dispersion.
Cowles, Martis W; Hubert, Amy; Zayas, Ricardo M
2012-05-01
Planarians are renowned for their capacity to replace lost tissues from adult pluripotent stem cells (neoblasts). Here we report that Lissencephaly-1 (lis1), which has roles in cellular processes such as mitotic spindle apparatus orientation and in signal regulation required for stem cell self-renewal, is required for stem cell maintenance in the planarian Schmidtea mediterranea. In planarians, lis1 is expressed in differentiated tissues and stem cells. lis1 RNAi leads to head regression, ventral curling, and death by lysis. By labeling the neoblasts and proliferating cells, we found lis1 knockdown animals show a dramatic increase in the number of mitotic cells, followed by depletion of the stem cell pool. Analysis of the mitotic spindles in dividing neoblasts revealed that defective spindle positioning is correlated with cells arrested at metaphase. In addition, we show that inhibiting a planarian homologue of nudE, predicted to encode a LIS-1 interacting protein, also leads to cell cycle progression defects. Our results provide evidence for a conserved role of LIS1 and NUDE in regulating the function of the mitotic spindle apparatus in a representative Lophotrochozoan and that planarians will be useful organisms in which to investigate LIS1 regulation of signaling events underlying stem cell self-renewal. Copyright © 2012 Wiley Periodicals, Inc.
Sinha, Rajnikant
2014-01-01
This book offers an introduction to the theory of smooth manifolds, helping students to familiarize themselves with the tools they will need for mathematical research on smooth manifolds and differential geometry. The book primarily focuses on topics concerning differential manifolds, tangent spaces, multivariable differential calculus, topological properties of smooth manifolds, embedded submanifolds, Sard’s theorem and Whitney embedding theorem. It is clearly structured, amply illustrated and includes solved examples for all concepts discussed. Several difficult theorems have been broken into many lemmas and notes (equivalent to sub-lemmas) to enhance the readability of the book. Further, once a concept has been introduced, it reoccurs throughout the book to ensure comprehension. Rank theorem, a vital aspect of smooth manifolds theory, occurs in many manifestations, including rank theorem for Euclidean space and global rank theorem. Though primarily intended for graduate students of mathematics, the book ...
Kato, M; Kimura, T; Lin, C; Ito, A; Kodama, S; Morikawa, T; Soga, T; Hayasaka, K
1999-04-01
The doublecortin (DCX) gene was recently found to be involved in patients with X-linked lissencephaly and subcortical band heterotopia or double cortex syndrome. We have studied the coding regions of the DCX gene in 11 Japanese patients with cortical dysplasia and have identified three different mutations (R186C in exon 3, R272X and R303X in exon 5) in four sporadic female cases. R272X, which has been detected in two unrelated cases, is a novel mutation. Although the number of cases studied remains limited, exon 5 may be a common mutational site in Japanese patients in contrast to many previous reports concerning exons 2 and 3.
Haverfield, Eden V; Whited, Amanda J; Petras, Kristin S; Dobyns, William B; Das, Soma
2009-07-01
Classical lissencephaly, or isolated lissencephaly sequence (ILS), and subcortical band heterotopia (SBH) are neuronal migration disorders associated with severe mental retardation and epilepsy. Abnormalities of the LIS1 and DCX genes are implicated in the majority of patients with these disorders and account for approximately 75% of patients with ILS, whereas mutations of DCX account for 85% of patients with SBH. The molecular basis of disease in patients with ILS and SBH, in whom no abnormalities have been identified, has been questioned. We studied a series of 83 patients with ILS, SBH or pachygyria, in whom no abnormalities of the LIS1 or DCX genes had been identified, for intragenic deletions and duplications by multiplex ligation-dependent probe amplification (MLPA). In 52 patients with ILS, we identified 12 deletions and 6 duplications involving the LIS1 gene (35%), with the majority resulting in grade 3 lissencephaly. Three deletions of the DCX gene were identified in the group of nine female patients with SBH (out of 31 patients with DCX-suggestive brain anomalies), ie 33%. We estimate an overall mutation detection rate of approximately 85% by LIS1 and DCX sequencing and MLPA in ILS, and 90% by DCX sequencing and MLPA in SBH. Our results show that intragenic deletions and duplications of the LIS1 and DCX genes account for a significant number of patients with ILS and SBH, where no molecular defect had previously been identified. Incorporation of deletion/duplication analysis of the LIS1 and DCX genes will be important for the molecular diagnosis of patients with ILS and SBH.
Energy Technology Data Exchange (ETDEWEB)
Righini, Andrea; Parazzini, Cecilia; Izzo, Giana [Children' s Hospital ' ' V. Buzzi' ' , Department of Radiology and Neuroradiology, Milan (Italy); Cesaretti, Claudia [Children' s Hospital ' ' V. Buzzi' ' , Department of Radiology and Neuroradiology, Milan (Italy); Ospedale Maggiore Policlinico, Medical Genetics Unit, Fondazione I.R.C.C.S. Ca' Granda, Milan (Italy); Conte, Giorgio [Children' s Hospital ' ' V. Buzzi' ' , Department of Radiology and Neuroradiology, Milan (Italy); University of Milan, Department of Health Sciences, Milan (Italy); Frassoni, Carolina; Inverardi, Francesca [Fondazione I.R.C.C.S. Istituto Neurologico ' ' C. Besta' ' , Clinical Epileptology and Experimental Neurophysiology Unit, Milan (Italy); Bulfamante, Gaetano; Avagliano, Laura [San Paolo Hospital, Division of Human Pathology, Milan (Italy); Rustico, Mariangela [Children' s Hospital ' ' V. Buzzi' ' , Department of Obstetrics and Gynaecology, Prenatal Diagnosis, Milan (Italy)
2016-03-15
Ganglionic eminence (GE) is a transient fetal brain structure that harvests a significant amount of precursors of cortical GABA-ergic interneurons. Prenatal magnetic resonance (MR) imaging features of GE anomalies (i.e., cavitations) have already been reported associated with severe micro-lissencephaly. The purpose of this report was to illustrate the MR imaging features of GE anomalies in conditions other than severe micro-lissencephalies. Among all the fetuses submitted to prenatal MR imaging at our center from 2005 to 2014, we collected eight cases with GE anomalies and only limited associated brain anomalies. The median gestational age at the time of MR imaging was 21 weeks ranging from 19 to 29 weeks. Two senior pediatric neuroradiologists categorized the anomalies of the GE region in two groups: group one showing cavitation in the GE region and group two showing enlarged GE region. For each fetal case, associated cranial anomalies were also reported. Five out of the eight cases were included in group one and three in group two. Besides the GE region abnormality, all eight cases had additional intracranial anomalies, such as mild partial callosal agenesis, vermian hypoplasia and rotation, cerebellar hypoplasia, ventriculomegaly, enlarged subarachnoid spaces, molar tooth malformation. Ultrasound generally detected most of the associated intracranial anomalies, prompting the MR investigation; on the contrary in none of the cases, GE anomalies had been detected by ultrasound. Our observation expands the spectrum of human GE anomalies, demonstrating that these may take place also without associated severe micro-lissencephalies. (orig.)
Lin, Chin-Yi; Chen, Chih-Ping; Liau, Chiung-Ling; Su, Pen-Hua; Tsao, Teng-Fu; Chang, Tung-Yao; Wang, Wayseen
2009-12-01
To present the prenatal magnetic resonance imaging (MRI) and ultrasound findings of Miller-Dieker lissencephaly syndrome (MDLS) associated with chromosome 17p13.3 deletion in a fetus. A 30-year-old, primigravid woman was referred to the hospital at 31 weeks' gestation because of intrauterine growth restriction (IUGR) and polyhydramnios detected by ultrasound. The pregnancy was uneventful until 31 weeks of gestation when IUGR and polyhydramnios were first noted. Level II ultrasound at 31 weeks' gestation showed fetal biometry equivalent to 27 weeks' gestation, an amniotic fluid index of 33.4 cm, ventriculomegaly, and abnormal sulcal development with absence of gyri and sulci, and a shallow Sylvian fissure. Other organs were unremarkable. Subsequent amniocentesis revealed a 46,XY,del(17)(p13.3) karyotype. Ultrafast fetal MRI performed at 34 weeks of gestation revealed agyria/pachygyria, a figure-eight appearance of the brain, a wide and shallow Sylvian fissure, enlarged subarachnoid space, ventriculomegaly, and polyhydramnios. At 35 weeks' gestation, a 1,346-g male baby was delivered with facial dysmorphism, characteristic of MDLS. Postnatal MRI confirmed the prenatal diagnosis. Polyhydramnios, IUGR and ventriculomegaly are important prenatal ultrasound markers of MDLS. Prenatal diagnosis of these markers should include a detailed investigation of cerebral sulci and fissures, and genetic analysis for MDLS. Fetal MRI is helpful for the diagnosis of lissencephaly.
Günther, Felix
2017-03-15
Polyhedral surfaces are fundamental objects in architectural geometry and industrial design. Whereas closeness of a given mesh to a smooth reference surface and its suitability for numerical simulations were already studied extensively, the aim of our work is to find and to discuss suitable assessments of smoothness of polyhedral surfaces that only take the geometry of the polyhedral surface itself into account. Motivated by analogies to classical differential geometry, we propose a theory of smoothness of polyhedral surfaces including suitable notions of normal vectors, tangent planes, asymptotic directions, and parabolic curves that are invariant under projective transformations. It is remarkable that seemingly mild conditions significantly limit the shapes of faces of a smooth polyhedral surface. Besides being of theoretical interest, we believe that smoothness of polyhedral surfaces is of interest in the architectural context, where vertices and edges of polyhedral surfaces are highly visible.
J.C. de Jongste (Johan)
1987-01-01
textabstractThe function of airway smooth muscle in normal subjects is not evident. Possible physiological roles include maintenance of optimal regional ventilation/perfusion ratios, reduction of anatomic dead space, stabilisation of cartilaginous bronchi, defense against impurities and, less
Laplacians on smooth distributions
Kordyukov, Yu. A.
2017-10-01
Let M be a compact smooth manifold equipped with a positive smooth density μ and let H be a smooth distribution endowed with a fibrewise inner product g. We define the Laplacian Δ_H associated with (H,μ,g) and prove that it gives rise to an unbounded self-adjoint operator in L^2(M,μ). Then, assuming that H generates a singular foliation \\mathscr F, we prove that, for any function \\varphi in the Schwartz space \\mathscr S( R), the operator \\varphi(Δ_H) is a smoothing operator in the scale of longitudinal Sobolev spaces associated with \\mathscr F. The proofs are based on pseudodifferential calculus on singular foliations, which was developed by Androulidakis and Skandalis, and on subelliptic estimates for Δ_H. Bibliography: 35 titles.
Energy Technology Data Exchange (ETDEWEB)
2017-12-12
smoothG is a collection of parallel C++ classes/functions that algebraically constructs reduced models of different resolutions from a given high-fidelity graph model. In addition, smoothG also provides efficient linear solvers for the reduced models. Other than pure graph problem, the software finds its application in subsurface flow and power grid simulations in which graph Laplacians are found
Jongste, Johan
1987-01-01
textabstractThe function of airway smooth muscle in normal subjects is not evident. Possible physiological roles include maintenance of optimal regional ventilation/perfusion ratios, reduction of anatomic dead space, stabilisation of cartilaginous bronchi, defense against impurities and, less likely, squeezing mucus out of mucous glands and pulling open the alveoli next to the airways1 . Any role of airway smooth muscle is necessarily limited, because an important degree of contraction will l...
Indian Academy of Sciences (India)
Annual Meetings · Mid Year Meetings · Discussion Meetings · Public Lectures · Lecture Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Proceedings – Mathematical Sciences; Volume 125; Issue 2. Smoothness of limit functors. Benedictus Margaux. Volume 125 Issue 2 May 2015 pp 161-165 ...
Smoothed Particle Hydrodynamic Simulator
Energy Technology Data Exchange (ETDEWEB)
2016-10-05
This code is a highly modular framework for developing smoothed particle hydrodynamic (SPH) simulations running on parallel platforms. The compartmentalization of the code allows for rapid development of new SPH applications and modifications of existing algorithms. The compartmentalization also allows changes in one part of the code used by many applications to instantly be made available to all applications.
Generalizing smooth transition autoregressions
DEFF Research Database (Denmark)
Chini, Emilio Zanetti
We introduce a variant of the smooth transition autoregression - the GSTAR model - capable to parametrize the asymmetry in the tails of the transition equation by using a particular generalization of the logistic function. A General-to-Specific modelling strategy is discussed in detail...
Smoothed Spectra, Ogives, and Error Estimates for Atmospheric Turbulence Data
Dias, Nelson Luís
2017-09-01
A systematic evaluation is conducted of the smoothed spectrum, which is a spectral estimate obtained by averaging over a window of contiguous frequencies. The technique is extended to the ogive, as well as to the cross-spectrum. It is shown that, combined with existing variance estimates for the periodogram, the variance—and therefore the random error—associated with these estimates can be calculated in a straightforward way. The smoothed spectra and ogives are biased estimates; with simple power-law analytical models, correction procedures are devised, as well as a global constraint that enforces Parseval's identity. Several new results are thus obtained: (1) The analytical variance estimates compare well with the sample variance calculated for the Bartlett spectrum and the variance of the inertial subrange of the cospectrum is shown to be relatively much larger than that of the spectrum. (2) Ogives and spectra estimates with reduced bias are calculated. (3) The bias of the smoothed spectrum and ogive is shown to be negligible at the higher frequencies. (4) The ogives and spectra thus calculated have better frequency resolution than the Bartlett spectrum, with (5) gradually increasing variance and relative error towards the low frequencies. (6) Power-law identification and extraction of the rate of dissipation of turbulence kinetic energy are possible directly from the ogive. (7) The smoothed cross-spectrum is a valid inner product and therefore an acceptable candidate for coherence and spectral correlation coefficient estimation by means of the Cauchy-Schwarz inequality. The quadrature, phase function, coherence function and spectral correlation function obtained from the smoothed spectral estimates compare well with the classical ones derived from the Bartlett spectrum.
Indian Academy of Sciences (India)
Indian Acad. Sci. (Math. Sci.) Vol. 125, No. 2, May 2015, pp. 161–165. c Indian Academy of Sciences. Smoothness of limit functors. BENEDICTUS MARGAUX. Laboratoire de Recherche “Princess .... On the same vein, the coaction cλ : A[X] → A[X][t±1] is defined 'at a finite level', that is, there exists α1 ≥ α0 and a Aα1 ...
Dabrowska, Dorota M.
1997-01-01
Nonparametric regression was shown by Beran and McKeague and Utikal to provide a flexible method for analysis of censored failure times and more general counting processes models in the presence of covariates. We discuss application of kernel smoothing towards estimation in a generalized Cox regression model with baseline intensity dependent on a covariate. Under regularity conditions we show that estimates of the regression parameters are asymptotically normal at rate root-n, and we also dis...
Smoothly Varying Bright Blazars
Van Alfen, Nicholas; Hindman, Lauren; Moody, Joseph Ward; Biancardi, Rochelle; Whipple, Parkes; Gaunt, Caleb
2018-01-01
It is becoming increasingly apparent that blazar light can vary sinusoidally with periods of hundreds of days to tens of years. Such behavior is expected of, among other things, jets coming from binary black holes. To look for general variability in lesser-known blazars and AGN, in 2015-2016 we monitored 182 objects with Johnson V-band magnitudes reported as being < 16. In all, this campaign generated 22,000 frames from 2,000 unique pointings. We find that approximately one dozen of these objects show evidence of smooth variability consistent with sinusoidal periods. We report on the entire survey sample, highlighting those that show sinusoidal variations.
Background Subtraction of Raman Spectra Based on Iterative Polynomial Smoothing.
Wang, Tuo; Dai, Liankui
2017-06-01
In this paper, a novel background subtraction algorithm is presented that can automatically recover Raman signal. This algorithm is based on an iterative polynomial smoothing method that highly reduces the need for experience and a priori knowledge. First, a polynomial filter is applied to smooth the input spectrum (the input spectrum is just an original spectrum at the first iteration). The output curve of the filter divides the original spectrum into two parts, top and bottom. Second, a proportion is calculated between the lowest point of the signal in the bottom part and the highest point of the signal in the top part. The proportion is a key index that decides whether to go into a new iteration. If a new iteration is needed, the minimum value between the output curve and the original spectrum forms a new curve that goes into the same filter in the first step and continues as another iteration until no more iteration is needed to finally get the background of the original spectrum. Results from the simulation experiments not only show that the iterative polynomial smoothing algorithm achieves good performance, processing time, cost, and accuracy of recovery, but also prove that the algorithm adapts to different background types and a large signal-to-noise ratio range. Furthermore, real measured Raman spectra of organic mixtures and non-organic samples are used to demonstrate the application of the algorithm.
Geographic smoothing of solar PV: results from Gujarat
Klima, Kelly; Apt, Jay
2015-10-01
We examine the potential for geographic smoothing of solar photovoltaic (PV) electricity generation using 13 months of observed power production from utility-scale plants in Gujarat, India. To our knowledge, this is the first published analysis of geographic smoothing of solar PV using actual generation data at high time resolution from utility-scale solar PV plants. We use geographic correlation and Fourier transform estimates of the power spectral density (PSD) to characterize the observed variability of operating solar PV plants as a function of time scale. Most plants show a spectrum that is linear in the log-log domain at high frequencies f, ranging from {f}-1.23 to {f}-1.56 (slopes of -1.23 and -1.56), thus exhibiting more relative variability at high frequencies than exhibited by wind plants. PSDs for large PV plants have a steeper slope than those for small plants, hence more smoothing at short time scales. Interconnecting 20 Gujarat plants yields a {f}-1.66 spectrum, reducing fluctuations at frequencies corresponding to 6 h and 1 h by 23% and 45%, respectively. Half of this smoothing can be obtained through connecting 4-5 plants; reaching marginal improvement of 1% per added plant occurs at 12-14 plants. The largest plant (322 MW) showed an {f}-1.76 spectrum. This suggests that in Gujarat the potential for smoothing is limited to that obtained by one large plant.
Classification of smooth Fano polytopes
DEFF Research Database (Denmark)
Øbro, Mikkel
A simplicial lattice polytope containing the origin in the interior is called a smooth Fano polytope, if the vertices of every facet is a basis of the lattice. The study of smooth Fano polytopes is motivated by their connection to toric varieties. The thesis concerns the classification of smooth...... Fano polytopes up to isomorphism. A smooth Fano -polytope can have at most vertices. In case of vertices an explicit classification is known. The thesis contains the classification in case of vertices. Classifications of smooth Fano -polytopes for fixed exist only for . In the thesis an algorithm...... for the classification of smooth Fano -polytopes for any given is presented. The algorithm has been implemented and used to obtain the complete classification for ....
Smoothing - Strichartz Estimates for the Schrodinger Equation with small Magnetic Potential
Georgiev, Vladimir; Stefanov, Atanas; Tarulli, Mirko
2005-01-01
The work treats smoothing and dispersive properties of solutions to the Schrodinger equation with magnetic potential. Under suitable smallness assumption on the potential involving scale invariant norms we prove smoothing - Strichartz estimate for the corresponding Cauchy problem. An application that guarantees absence of pure point spectrum of the corresponding perturbed Laplace operator is discussed too.
Dynamics of smooth muscle contraction
G.A. van Kloeveringe (Gommert)
1997-01-01
textabstractSmooth muscle can economically maintain tonus for a long time and in many organs, its purpose is to maintain organ dimensions. It is however relatively slow and also inefficient as far as mechanical work is concerned. Smooth muscle is found in the majority of organs in the human body. It
Smooth analysis in Banach spaces
Hájek, Petr
2014-01-01
This bookis aboutthe subject of higher smoothness in separable real Banach spaces.It brings together several angles of view on polynomials, both in finite and infinite setting.Also a rather thorough and systematic view of the more recent results, and the authors work is given. The book revolves around two main broad questions: What is the best smoothness of a given Banach space, and its structural consequences? How large is a supply of smooth functions in the sense of approximating continuous functions in the uniform topology, i.e. how does the Stone-Weierstrass theorem generalize into in
Smooth Sailing with Contract Services.
Fickes, Michael
2001-01-01
Discusses how to make the contract services relationship work smoothly for educational facilities. Covers topics of food, child care, and transportation services, along with a brief explanation of the benefits of outsourcing on-campus amenities. (GR)
on gastro intestinal smooth muscle
African Journals Online (AJOL)
USER
, Kaduna State. Correspondence author: am.huguma@yahoo.com. ABSTRACT. The effects of the aqueous leaf extract of Combretum micranthum were studied on gastro intestinal smooth muscle of rodents. The extract was screened using ...
Aging and gastrointestinal smooth muscle.
Bitar, Khalil N; Patil, Suresh B
2004-12-01
The present review is an attempt to put into perspective the available information on the putative changes in cellular mechanisms of the contractile properties of the aging gastrointestinal (GI) smooth muscle. Information on smooth muscle of the GI tract is scanty. Smooth muscle cells from old rats (32 months old) exhibit limited cell length distribution and diminished contractility. The observed reduced contractile response may be due to the effect of aging on signal transduction pathways, especially an inhibition of the tyrosine kinase-Src kinase pathway, a reduced activation of the PKCalpha pathway, a reduced association of contractile proteins (HSP27-tropomyosin, HSP27-actin, and actin-myosin). Levels of HSP27-phosphorylation are also reduced compared to adult rats. Regulation of GI motility is a complex mechanism of signal transduction and interaction of signaling and contractile proteins. It is suggested that further studies to elucidate the role of HSP27 in aging smooth muscle of the GI tract are needed.
Smooth Nonparametric Bernstein Vine Copulas
Weiß, Gregor; Scheffer, Marcus
2012-01-01
We propose to use nonparametric Bernstein copulas as bivariate pair-copulas in high-dimensional vine models. The resulting smooth and nonparametric vine copulas completely obviate the error-prone need for choosing the pair-copulas from parametric copula families. By means of a simulation study and an empirical analysis of financial market data, we show that our proposed smooth nonparametric vine copula model is superior to competing parametric vine models calibrated via Akaike's Information C...
Radar data smoothing filter study
White, J. V.
1984-01-01
The accuracy of the current Wallops Flight Facility (WFF) data smoothing techniques for a variety of radars and payloads is examined. Alternative data reduction techniques are given and recommendations are made for improving radar data processing at WFF. A data adaptive algorithm, based on Kalman filtering and smoothing techniques, is also developed for estimating payload trajectories above the atmosphere from noisy time varying radar data. This algorithm is tested and verified using radar tracking data from WFF.
Exotic smoothness and quantum gravity
Energy Technology Data Exchange (ETDEWEB)
Asselmeyer-Maluga, T, E-mail: torsten.asselmeyer-maluga@dlr.d [German Aerospace Center, Berlin, Germany and Loyola University, New Orleans, LA (United States)
2010-08-21
Since the first work on exotic smoothness in physics, it was folklore to assume a direct influence of exotic smoothness to quantum gravity. Thus, the negative result of Duston (2009 arXiv:0911.4068) was a surprise. A closer look into the semi-classical approach uncovered the implicit assumption of a close connection between geometry and smoothness structure. But both structures, geometry and smoothness, are independent of each other. In this paper we calculate the 'smoothness structure' part of the path integral in quantum gravity assuming that the 'sum over geometries' is already given. For that purpose we use the knot surgery of Fintushel and Stern applied to the class E(n) of elliptic surfaces. We mainly focus our attention to the K3 surfaces E(2). Then we assume that every exotic smoothness structure of the K3 surface can be generated by knot or link surgery in the manner of Fintushel and Stern. The results are applied to the calculation of expectation values. Here we discuss the two observables, volume and Wilson loop, for the construction of an exotic 4-manifold using the knot 5{sub 2} and the Whitehead link Wh. By using Mostow rigidity, we obtain a topological contribution to the expectation value of the volume. Furthermore, we obtain a justification of area quantization.
... Us Donate The Zellweger Spectrum Zellweger Syndrome, Neonatal Adrenoleukodystrophy (NALD), and Infantile Refsum’s Disease (IRD) The disorders ... of the Zellweger spectrum: Zellweger syndrome (ZS), neonatal adrenoleukodystrophy (NALD), and infantile Refsum disease (IRD). While these ...
2000-01-01
The book provides a self-contained introduction to the mathematical theory of non-smooth dynamical problems, as they frequently arise from mechanical systems with friction and/or impacts. It is aimed at applied mathematicians, engineers, and applied scientists in general who wish to learn the subject.
Income smoothing by Dutch hospitals
Boterenbrood, D.R.
2014-01-01
Research indicates that hospitals manage their earnings. However, these findings might be influenced by methodological issues. In this study, I exploit specific features of Dutch hospitals to study income smoothing while limiting these methodological issues. The managers of Dutch hospitals have the
Panel Smooth Transition Regression Models
DEFF Research Database (Denmark)
González, Andrés; Terasvirta, Timo; Dijk, Dick van
We introduce the panel smooth transition regression model. This new model is intended for characterizing heterogeneous panels, allowing the regression coefficients to vary both across individuals and over time. Specifically, heterogeneity is allowed for by assuming that these coefficients are bou...
Green, J. L.
1986-01-01
Although automatic, computer scaling methods appeared at the start of the MST (mesosphere stratosphere troposphere) radar technique, there is a continuing need for scaling algorithms that perform editing functions and increase the sensitivity of radar by post processing. The scaling method presented is an adaptation of the method of scaling MST Doppler spectra presented by Rastogi (1984). A brief overview of this method is as follows: a median spectrum is calculated from several sequential spectra; the median noise value is subtracted from this derived spectrum; the median spectrum is smoothed; the detection/nondetection decision is made by comparing the smoothed spectrum to the variance of the smoothed noise; and if a signal is detected, then the half-power points of the smoothed echo spectrum are used to place limits on the evaluation of the first two moments of the unsmoothed median spectrum. In all of the above steps, the algorithm is guided by tracing the expected velocity range upward from the lowest range as far as possible. The method is discussed in more detail.
Smooth paths of conditional expectations
Andruchow, Esteban; Larotonda, Gabriel
2010-01-01
Let A be a von Neumann algebra with a finite trace $\\tau$, represented in $H=L^2(A,\\tau)$, and let $B_t\\subset A$ be sub-algebras, for $t$ in an interval $I$. Let $E_t:A\\to B_t$ be the unique $\\tau$-preserving conditional expectation. We say that the path $t\\mapsto E_t$ is smooth if for every $a\\in A$ and $v \\in H$, the map $$ I\
Beam smoothing and temporal effects
Energy Technology Data Exchange (ETDEWEB)
Hora, H.; Aydin, M.; Eliezer, S.; Goldsworthy, M.P.; Min, G.; Gahatak, A.K.; Lalousis, P.; Stening, R.J.; Szichman, H. [University of Technology, Sydney, NSW (Australia); Boreham, B.W. [Queensland Inst. of Tech., Gardens Point, QLD (Australia). Dept. of Physics; Luther-Davies, B.; Baldwin, K.G.H.; Rode, A.V. [Australian National Univ., Canberra, ACT (Australia)
1995-05-01
Until recently, and in spite of the introduction of smoothing methods, direct drive laser fusion received lots of setbacks from experiments, this being due to nonlinear and anomalous phenomena. This report deals with a method of analysis which, as self-generated von-Laue gratings, preventing the propagation of laser radiation through the outermost plasma corona, and preventing energy deposition. (TEC). 36 refs., 5 figs.
The Spectrum of Wind Power Fluctuations
Bandi, Mahesh
2016-11-01
Wind is a variable energy source whose fluctuations threaten electrical grid stability and complicate dynamical load balancing. The power generated by a wind turbine fluctuates due to the variable wind speed that blows past the turbine. Indeed, the spectrum of wind power fluctuations is widely believed to reflect the Kolmogorov spectrum; both vary with frequency f as f - 5 / 3. This variability decreases when aggregate power fluctuations from geographically distributed wind farms are averaged at the grid via a mechanism known as geographic smoothing. Neither the f - 5 / 3 wind power fluctuation spectrum nor the mechanism of geographic smoothing are understood. In this work, we explain the wind power fluctuation spectrum from the turbine through grid scales. The f - 5 / 3 wind power fluctuation spectrum results from the largest length scales of atmospheric turbulence of order 200 km influencing the small scales where individual turbines operate. This long-range influence spatially couples geographically distributed wind farms and synchronizes farm outputs over a range of frequencies and decreases with increasing inter-farm distance. Consequently, aggregate grid-scale power fluctuations remain correlated, and are smoothed until they reach a limiting f - 7 / 3 spectrum. This work was funded by the Collective Interactions Unit, OIST Graduate University, Japan.
When does the H∞ fixed-lag smoothing saturate for finite smoothing lag
Mirkin, Leonid; Meinsma, Gjerrit
2004-01-01
A notable difference between the H∞ smoothing is that the achievable performance in the latter problem might "saturate" as the function of the smoothing lag in the sense that there might exist a finite smoothing lag for which the achievable performance level is the same as for the infinite smoothing
s-SMOOTH: Sparsity and Smoothness Enhanced EEG Brain Tomography
Directory of Open Access Journals (Sweden)
Ying Li
2016-11-01
Full Text Available EEG source imaging enables us to reconstruct current density in the brain from the electrical measurements with excellent temporal resolution (~ms. The corresponding EEG inverse problem is an ill-posed one that has infinitely many solutions. This is due to the fact that the number of EEG sensors is usually much smaller than that of the potential dipole locations, as well as noise contamination in the recorded signals. To obtain a unique solution, regularizations can be incorporated to impose additional constraints on the solution. An appropriate choice of regularization is critically important for the reconstruction accuracy of the brain image. In this paper, we propose a novel Sparsity and SMOOthness enhanced brain TomograpHy (s-SMOOTH method to improve the reconstruction accuracy by integrating two recently proposed regularization techniques: Total Generalized Variation (TGV regularization and l_(1-2 regularization. TGV is able to preserve the source edge and recover the spatial distribution of the source intensity with high accuracy. Compared to the relevant total variation (TV regularization, TGV enhances the smoothness of the image and reduces staircasing artifacts. The traditional TGV defined on a 2D image has been widely used in image processing field. In order to handle 3D EEG source images, we propose a voxel-based TGV (vTGV regularization that extends the definition of second-order TGV from 2D planar image to 3D irregular surfaces such as cortex surface. In addition, the l_(1-2 regularization is utilized to promote sparsity on the current density itself. We demonstrate that l_(1-2 regularization is able to enhance sparsity and accelerate computations than l_1 regularization. The proposed model is solved by an efficient and robust algorithm based on the difference of convex functions algorithm (DCA and the alternating direction method of multipliers (ADMM. Numerical experiments using synthetic data demonstrate the advantages of the
s-SMOOTH: Sparsity and Smoothness Enhanced EEG Brain Tomography.
Li, Ying; Qin, Jing; Hsin, Yue-Loong; Osher, Stanley; Liu, Wentai
2016-01-01
EEG source imaging enables us to reconstruct current density in the brain from the electrical measurements with excellent temporal resolution (~ ms). The corresponding EEG inverse problem is an ill-posed one that has infinitely many solutions. This is due to the fact that the number of EEG sensors is usually much smaller than that of the potential dipole locations, as well as noise contamination in the recorded signals. To obtain a unique solution, regularizations can be incorporated to impose additional constraints on the solution. An appropriate choice of regularization is critically important for the reconstruction accuracy of a brain image. In this paper, we propose a novel Sparsity and SMOOthness enhanced brain TomograpHy (s-SMOOTH) method to improve the reconstruction accuracy by integrating two recently proposed regularization techniques: Total Generalized Variation (TGV) regularization and ℓ1-2 regularization. TGV is able to preserve the source edge and recover the spatial distribution of the source intensity with high accuracy. Compared to the relevant total variation (TV) regularization, TGV enhances the smoothness of the image and reduces staircasing artifacts. The traditional TGV defined on a 2D image has been widely used in the image processing field. In order to handle 3D EEG source images, we propose a voxel-based Total Generalized Variation (vTGV) regularization that extends the definition of second-order TGV from 2D planar images to 3D irregular surfaces such as cortex surface. In addition, the ℓ1-2 regularization is utilized to promote sparsity on the current density itself. We demonstrate that ℓ1-2 regularization is able to enhance sparsity and accelerate computations than ℓ1 regularization. The proposed model is solved by an efficient and robust algorithm based on the difference of convex functions algorithm (DCA) and the alternating direction method of multipliers (ADMM). Numerical experiments using synthetic data demonstrate the
Smooth Adaptation by Sigmoid Shrinkage
Directory of Open Access Journals (Sweden)
Atto AbdourrahmaneM
2009-01-01
Full Text Available This paper addresses the properties of a subclass of sigmoid-based shrinkage functions: the non zeroforcing smooth sigmoid-based shrinkage functions or SigShrink functions. It provides a SURE optimization for the parameters of the SigShrink functions. The optimization is performed on an unbiased estimation risk obtained by using the functions of this subclass. The SURE SigShrink performance measurements are compared to those of the SURELET (SURE linear expansion of thresholds parameterization. It is shown that the SURE SigShrink performs well in comparison to the SURELET parameterization. The relevance of SigShrink is the physical meaning and the flexibility of its parameters. The SigShrink functions performweak attenuation of data with large amplitudes and stronger attenuation of data with small amplitudes, the shrinkage process introducing little variability among data with close amplitudes. In the wavelet domain, SigShrink is particularly suitable for reducing noise without impacting significantly the signal to recover. A remarkable property for this class of sigmoid-based functions is the invertibility of its elements. This propertymakes it possible to smoothly tune contrast (enhancement, reduction.
Pioline, Boris
2015-01-01
In $D=4,N=2$ theories on $R^{3,1}$, the index receives contributions not only from single-particle BPS states, counted by the BPS indices, but also from multi-particle states made of BPS constituents. In a recent work [arXiv:1406.2360], a general formula expressing the index in terms of the BPS indices was proposed, which is smooth across walls of marginal stability and reproduces the expected single-particle contributions. In this note, I analyze the two-particle contributions predicted by this formula, and show agreement with the spectral asymmetry of the continuum of scattering states in the supersymmetric quantum mechanics of two non-relativistic, mutually non-local dyons. This provides a physical justification for the error function profile used in the mathematics literature on indefinite theta series, and in the physics literature on black hole partition functions.
Smooth ergodic theory for endomorphisms
Qian, Min; Zhu, Shu
2009-01-01
This volume presents a general smooth ergodic theory for deterministic dynamical systems generated by non-invertible endomorphisms, mainly concerning the relations between entropy, Lyapunov exponents and dimensions. The authors make extensive use of the combination of the inverse limit space technique and the techniques developed to tackle random dynamical systems. The most interesting results in this book are (1) the equivalence between the SRB property and Pesin’s entropy formula; (2) the generalized Ledrappier-Young entropy formula; (3) exact-dimensionality for weakly hyperbolic diffeomorphisms and for expanding maps. The proof of the exact-dimensionality for weakly hyperbolic diffeomorphisms seems more accessible than that of Barreira et al. It also inspires the authors to argue to what extent the famous Eckmann-Ruelle conjecture and many other classical results for diffeomorphisms and for flows hold true. After a careful reading of the book, one can systematically learn the Pesin theory for endomorphis...
Autoregressive smoothing of GOMOS transmittances
Fussen, D.; Vanhellemont, F.; Bingen, C.; Kyrölä, B.; Tamminen, J.; Sofieva, V.; Hassinen, S.; Seppälä, A.; Verronen, P. T.; Bertaux, J. L.; Hauchecorne, A.; Dalaudier, F.; d'Andon, O. Fanton; Barrot, G.; Mangin, A.; Theodore, B.; Guirlet, M.; Renard, J. B.; Fraisse, R.; Snoeij, P.; Koopman, R.; Saavedra, L.
GOMOS is a stellar occultation instrument onboard ENVISAT. It has already measured several hundreds of thousands occultations since March 2002. In some circumstances, the obliqueness of the star setting causes the remote sounding of possible horizontal turbulence that cannot be adequately corrected by using the fast photometer signals, leading to the presence of residual scintillation in the atmospheric transmittance. We investigate the mechanism that produces this spurious signal that may cause the retrieval of wavy constituent profiles. A special algorithm of vertical autoregressive smoothing (VAS) is proposed that takes into account the physical correlation between adjacent measurements at different tangent altitudes. A regularization parameter of the method may be optimized on basis of the minimal correlation between the residuals as prescribed by the Durbin-Watson statistics. The improvements obtained in the retrieval of both O 3 and NO 2 number density profiles is presented and discussed with respect to the results of the official data processing model.
Properties of the extremal infinite smooth words
Directory of Open Access Journals (Sweden)
Srecko Brlek
2007-05-01
Full Text Available Smooth words are connected to the Kolakoski sequence. We construct the maximal and the minimal infinite smooth words, with respect to the lexicographical order. The naive algorithm generating them is improved by using a reduction of the De Bruijn graph of their factors. We also study their Lyndon factorizations. Finally, we show that the minimal smooth word over the alphabet {1,3} belongs to the orbit of the Fibonacci word.
Smoothed analysis of complex conic condition numbers
Buergisser, Peter; Cucker, Felipe; Lotz, Martin
2006-01-01
Smoothed analysis of complexity bounds and condition numbers has been done, so far, on a case by case basis. In this paper we consider a reasonably large class of condition numbers for problems over the complex numbers and we obtain smoothed analysis estimates for elements in this class depending only on geometric invariants of the corresponding sets of ill-posed inputs. These estimates are for a version of smoothed analysis proposed in this paper which, to the best of our knowledge, appears ...
DEFF Research Database (Denmark)
Henten, Anders; Tadayoni, Reza; Windekilde, Iwona Maria
a conflict in accessing to the valuable spectrum resources allocated to TV broadcast that has been there for many years and which has been intensified in different phases of technological development and the second being an obvious conflict of interest between the different stake holders within the mobile...
Smooth horizons and quantum ripples
Golovnev, Alexey
2014-01-01
Black Holes are unique objects which allow for meaningful theoretical studies of strong gravity and even quantum gravity effects. An infalling and a distant observer would have very different views on the structure of the world. However, a careful analysis has shown that it entails no genuine contradictions for physics, and the paradigm of observer complementarity has been coined. Recently this picture was put into doubt. In particular, it was argued that in old Black Holes a firewall must form in order to protect the basic principles of quantum mechanics. This AMPS paradox has already been discussed in a vast number of papers with different attitudes and conclusions. Here we want to argue that a possible source of confusion is neglection of quantum gravity effects. Contrary to widespread perception, it does not necessarily mean that effective field theory is inapplicable in rather smooth neighbourhoods of large Black Hole horizons. The real offender might be an attempt to consistently use it over the huge di...
Local Transfer Coefficient, Smooth Channel
Directory of Open Access Journals (Sweden)
R. T. Kukreja
1998-01-01
Full Text Available Naphthalene sublimation technique and the heat/mass transfer analogy are used to determine the detailed local heat/mass transfer distributions on the leading and trailing walls of a twopass square channel with smooth walls that rotates about a perpendicular axis. Since the variation of density is small in the flow through the channel, buoyancy effect is negligible. Results show that, in both the stationary and rotating channel cases, very large spanwise variations of the mass transfer exist in he turn and in the region immediately downstream of the turn in the second straight pass. In the first straight pass, the rotation-induced Coriolis forces reduce the mass transfer on the leading wall and increase the mass transfer on the trailing wall. In the turn, rotation significantly increases the mass transfer on the leading wall, especially in the upstream half of the turn. Rotation also increases the mass transfer on the trailing wall, more in the downstream half of the turn than in the upstream half of the turn. Immediately downstream of the turn, rotation causes the mass transfer to be much higher on the trailing wall near the downstream corner of the tip of the inner wall than on the opposite leading wall. The mass transfer in the second pass is higher on the leading wall than on the trailing wall. A slower flow causes higher mass transfer enhancement in the turn on both the leading and trailing walls.
Smoothing a Piecewise-Smooth: An Example from Plankton Population Dynamics
DEFF Research Database (Denmark)
Piltz, Sofia Helena
2016-01-01
In this work we discuss a piecewise-smooth dynamical system inspired by plankton observations and constructed for one predator switching its diet between two different types of prey. We then discuss two smooth formulations of the piecewise-smooth model obtained by using a hyperbolic tangent...
The smoothness criterion as a trend diagnostic
P. Fogarty; Weber, N.C.
2006-01-01
The smoothness criterion is used in the design of symmetric moving average trend filters in time series and in graduation in actuarial studies. This measure of smoothness is used to motivate a diagnostic for determining the order of local polynomial trend.
Very smooth points of spaces of operators
Indian Academy of Sciences (India)
Home; Journals; Proceedings – Mathematical Sciences; Volume 113; Issue 1 ... We show that when the space of compact operators is an -ideal in the space of bounded operators, a very smooth operator attains its norm at a unique vector (up to a constant multiple) and ( ) is a very smooth point of the range space.
Smoothed Analysis of Local Search Algorithms
Manthey, Bodo; Dehne, Frank; Sack, Jörg-Rüdiger; Stege, Ulrike
2015-01-01
Smoothed analysis is a method for analyzing the performance of algorithms for which classical worst-case analysis fails to explain the performance observed in practice. Smoothed analysis has been applied to explain the performance of a variety of algorithms in the last years. One particular class of
Income and Consumption Smoothing among US States
DEFF Research Database (Denmark)
Sørensen, Bent; Yosha, Oved
within regions but not between regions. This suggests that capital markets transcend regional barriers while credit markets are regional in their nature. Smoothing within the club of rich states is accomplished mainly via capital markets whereas consumption smoothing is dominant within the club of poor...
The smoothness criterion as a trend diagnostic
Directory of Open Access Journals (Sweden)
2006-01-01
Full Text Available The smoothness criterion is used in the design of symmetric moving average trend filters in time series and in graduation in actuarial studies. This measure of smoothness is used to motivate a diagnostic for determining the order of local polynomial trend.
The smoothness criterion as a trend diagnostic
Directory of Open Access Journals (Sweden)
N. C. Weber
2006-02-01
Full Text Available The smoothness criterion is used in the design of symmetric moving average trend filters in time series and in graduation in actuarial studies. This measure of smoothness is used to motivate a diagnostic for determining the order of local polynomial trend.
Very smooth points of spaces of operators
Indian Academy of Sciences (India)
R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22
or Y has the compact metric approximation property (CMAP), then it is easy to see that K (X, Y ) ⊂ L(X, Y ) satisfies the above condition (see [R6]). Thus for a compact operator that is a very smooth point, directional derivatives exist in the direction of all bounded operators. Smooth points of operator spaces has been ...
Spline-Based Smoothing of Airfoil Curvatures
Li, W.; Krist, S.
2008-01-01
Constrained fitting for airfoil curvature smoothing (CFACS) is a splinebased method of interpolating airfoil surface coordinates (and, concomitantly, airfoil thicknesses) between specified discrete design points so as to obtain smoothing of surface-curvature profiles in addition to basic smoothing of surfaces. CFACS was developed in recognition of the fact that the performance of a transonic airfoil is directly related to both the curvature profile and the smoothness of the airfoil surface. Older methods of interpolation of airfoil surfaces involve various compromises between smoothing of surfaces and exact fitting of surfaces to specified discrete design points. While some of the older methods take curvature profiles into account, they nevertheless sometimes yield unfavorable results, including curvature oscillations near end points and substantial deviations from desired leading-edge shapes. In CFACS as in most of the older methods, one seeks a compromise between smoothing and exact fitting. Unlike in the older methods, the airfoil surface is modified as little as possible from its original specified form and, instead, is smoothed in such a way that the curvature profile becomes a smooth fit of the curvature profile of the original airfoil specification. CFACS involves a combination of rigorous mathematical modeling and knowledge-based heuristics. Rigorous mathematical formulation provides assurance of removal of undesirable curvature oscillations with minimum modification of the airfoil geometry. Knowledge-based heuristics bridge the gap between theory and designers best practices. In CFACS, one of the measures of the deviation of an airfoil surface from smoothness is the sum of squares of the jumps in the third derivatives of a cubicspline interpolation of the airfoil data. This measure is incorporated into a formulation for minimizing an overall deviation- from-smoothness measure of the airfoil data within a specified fitting error tolerance. CFACS has been
Lunar Smooth Plains Identification and Classification
Boyd, A. K.; Robinson, M. S.; Mahanti, P.; Lawrence, S. J.; Spudis, P.; Jolliff, B. L.
2012-12-01
Smooth plains are widespread on the Moon and have diverse origins. The maria comprise the majority of the smooth plains and are volcanic in origin. Highland smooth plains are patchy, and tend to fill large craters and basins; their origins have eluded unambiguous classification. Prior to the Apollo 16 mission, many workers thought that highland plains were volcanic, possibly more silicic than the maria. However, as the Apollo 16 samples are mostly impact breccias, the highland smooth plains were re-interpreted basin impact ejecta, most likely from the Imbrium and possibly Orientale basins. Conversely, some known non-mare volcanic units, such as the Apennine Bench Formation, contain light plains. These interpretations do not rule out alternate origins for a subset of highland smooth plains, including impact melt or volcanic origins (effusive or pyroclastic). We developed an algorithm to identify smooth plains using topographic parameters from the WAC Global Lunar Digital Terrain Model (DTM) (GLD100), sampled at 333 m/pixel. We classify the smooth plains using the Clementine UVVIS FeO map and photometrically corrected Lunar Reconnaissance Orbiter Camera (LROC) Wide Angle Camera (WAC) images. Terrain with slopes less than 2° (1 km baseline) and standard deviation of slope less than 0.75° (1 km x 1 km box, n=9) are defined as smooth plains. Highland smooth plains are distinguished from basaltic smooth plains using the following criteria: LROC WAC 643 nm normalized reflectance > 0.056, LROC WAC 321 nm / 415 nm ratio 0.77 is termed blue maria and a ratio ≤ 0.77 is termed red maria. The automatic classification was limited to the 87% of the Moon covered by photometrically normalized WAC data (60°S to 60°N). The differences between the maria and highland smooth plains deposits were more ambiguous in regions where the Clementine data had gores and albedo of the maria was elevated (i.e. Mare Frigoris and eastern Imbrium basin). For example, Schickard crater hosts a
Progress in smooth particle hydrodynamics
Energy Technology Data Exchange (ETDEWEB)
Wingate, C.A.; Dilts, G.A.; Mandell, D.A.; Crotzer, L.A.; Knapp, C.E.
1998-07-01
Smooth Particle Hydrodynamics (SPH) is a meshless, Lagrangian numerical method for hydrodynamics calculations where calculational elements are fuzzy particles which move according to the hydrodynamic equations of motion. Each particle carries local values of density, temperature, pressure and other hydrodynamic parameters. A major advantage of SPH is that it is meshless, thus large deformation calculations can be easily done with no connectivity complications. Interface positions are known and there are no problems with advecting quantities through a mesh that typical Eulerian codes have. These underlying SPH features make fracture physics easy and natural and in fact, much of the applications work revolves around simulating fracture. Debris particles from impacts can be easily transported across large voids with SPH. While SPH has considerable promise, there are some problems inherent in the technique that have so far limited its usefulness. The most serious problem is the well known instability in tension leading to particle clumping and numerical fracture. Another problem is that the SPH interpolation is only correct when particles are uniformly spaced a half particle apart leading to incorrect strain rates, accelerations and other quantities for general particle distributions. SPH calculations are also sensitive to particle locations. The standard artificial viscosity treatment in SPH leads to spurious viscosity in shear flows. This paper will demonstrate solutions for these problems that they and others have been developing. The most promising is to replace the SPH interpolant with the moving least squares (MLS) interpolant invented by Lancaster and Salkauskas in 1981. SPH and MLS are closely related with MLS being essentially SPH with corrected particle volumes. When formulated correctly, JLS is conservative, stable in both compression and tension, does not have the SPH boundary problems and is not sensitive to particle placement. The other approach to
Smoothing properties for Hirota-Satsuma systems
Directory of Open Access Journals (Sweden)
S. Jimenez
2011-08-01
Full Text Available We study local existence and smoothing properties for the initial value problem associated to Hirota-Satsuma systems that describes an interaction of two long waves with different dispersion relations.
Smooth surfaces from rational bilinear patches
Shi, Ling
2014-01-01
Smooth freeform skins from simple panels constitute a challenging topic arising in contemporary architecture. We contribute to this problem area by showing how to approximate a negatively curved surface by smoothly joined rational bilinear patches. The approximation problem is solved with help of a new computational approach to the hyperbolic nets of Huhnen-Venedey and Rörig and optimization algorithms based on it. We also discuss its limits which lie in the topology of the input surface. Finally, freeform deformations based on Darboux transformations are used to generate smooth surfaces from smoothly joined Darboux cyclide patches; in this way we eliminate the restriction to surfaces with negative Gaussian curvature. © 2013 Elsevier B.V.
Smoothed generalized free energies for thermodynamics
van der Meer, Remco; Ng, Nelly Huei Ying; Wehner, Stephanie
2017-12-01
In the study of thermodynamics for nanoscale quantum systems, a family of quantities known as generalized free energies have been derived as necessary and sufficient conditions that govern state transitions. These free energies become important especially in the regime where the system of interest consists of only a few (quantum) particles. In this work, we introduce a family of smoothed generalized free energies, by constructing explicit smoothing procedures that maximize or minimize the free energy over an ɛ ball of quantum states. In contrast to previously known smoothed free energies, these quantities now allow us to make an operational statement for approximate thermodynamic state transitions. We show that these smoothed quantities converge to the standard free energy in the thermodynamic limit.
Doing smooth pursuit paradigms in Windows 7
DEFF Research Database (Denmark)
Wilms, Inge Linda
Smooth pursuit eye movements are interesting to study as they reflect the subject’s ability to predict movement of external targets, keep focus and move the eyes appropriately. The process of smooth pursuit requires collaboration between several systems in the brain and the resulting action may p...... in Windows 7 with live capturing of eye movements using a Tobii TX300 eye tracker. In particular, the poster describes the challenges and limitations created by the hardware and the software...
Kalman Filter Desing, Smoothing and Analysis
Cederkvist, Henrik Rene
2001-01-01
Thesis is based on three different aspects of Kalman filtering. >Kalman filters for navigation. Investigate the difference between a Extended Kalman Filter and a Linearized Kalman Filter with feedback. And show how different system models relate to these Kalman Filters when implemented in a filter. >Smoothing. Investigate how much there is to be gained from smoothing. We will only look at the fixed-interval smoother, using the method of forward and backward filtering. ...
Smooth embeddings with Stein surface images
Gompf, Robert E.
2011-01-01
A simple characterization is given of open subsets of a complex surface that smoothly perturb to Stein open subsets. As applications, complex 2-space C^2 contains domains of holomorphy (Stein open subsets) that are exotic R^4's, and others homotopy equivalent to the 2-sphere but cut out by smooth, compact 3-manifolds. Pseudoconvex embeddings of Brieskorn spheres and other 3-manifolds into complex surfaces are constructed, as are pseudoconcave holomorphic fillings (with disagreeing contact and...
Some splines produced by smooth interpolation
Czech Academy of Sciences Publication Activity Database
Segeth, Karel
2018-01-01
Roč. 319, 15 February (2018), s. 387-394 ISSN 0096-3003 R&D Projects: GA ČR GA14-02067S Institutional support: RVO:67985840 Keywords : smooth data approximation * smooth data interpolation * cubic spline Subject RIV: BA - General Mathematics Impact factor: 1.738, year: 2016 http://www.sciencedirect.com/science/article/pii/S0096300317302746?via%3Dihub
Beam-smoothing investigation on Heaven I
Xiang, Yi-huai; Gao, Zhi-xing; Tong, Xiao-hui; Dai, Hui; Tang, Xiu-zhang; Shan, Yu-sheng
2007-01-01
Directly driven targets for inertial confinement fusion (ICF) require laser beams with extremely smooth irradiance profiles to prevent hydrodynamic instabilities that destroy the spherical symmetry of the target during implosion. Such instabilities can break up and mix together the target's wall and fuel material, preventing it from reaching the density and temperature required for fusion ignition. 1,2 Measurements in the equation of state (EOS) experiments require laser beams with flat-roofed profiles to generate uniform shockwave 3. Some method for beam smooth, is thus needed. A technique called echelon-free induced spatial incoherence (EFISI) is proposed for producing smooth target beam profiles with large KrF lasers. The idea is basically an image projection technique that projects the desired time-averaged spatial profile onto the target via the laser system, using partially coherent broadband lighe. Utilize the technique, we developing beam- smoothing investigation on "Heaven I". At China Institute of Atomic Energy , a new angular multiplexing providing with beam-smoothing function has been developed, the total energy is 158J, the stability of energy is 4%, the pulse duration is 25ns, the effective diameter of focusing spot is 400um, and the ununiformity is about 1.6%, the power density on the target is about 3.7×10 12W/cm2. At present, the system have provided steady and smooth laser irradiation for EOS experiments.
Nonequilibrium flows with smooth particle applied mechanics
Energy Technology Data Exchange (ETDEWEB)
Kum, Oyeon [Univ. of California, Davis, CA (United States)
1995-07-01
Smooth particle methods are relatively new methods for simulating solid and fluid flows through they have a 20-year history of solving complex hydrodynamic problems in astrophysics, such as colliding planets and stars, for which correct answers are unknown. The results presented in this thesis evaluate the adaptability or fitness of the method for typical hydrocode production problems. For finite hydrodynamic systems, boundary conditions are important. A reflective boundary condition with image particles is a good way to prevent a density anomaly at the boundary and to keep the fluxes continuous there. Boundary values of temperature and velocity can be separately controlled. The gradient algorithm, based on differentiating the smooth particle expression for (uρ) and (Tρ), does not show numerical instabilities for the stress tensor and heat flux vector quantities which require second derivatives in space when Fourier`s heat-flow law and Newton`s viscous force law are used. Smooth particle methods show an interesting parallel linking to them to molecular dynamics. For the inviscid Euler equation, with an isentropic ideal gas equation of state, the smooth particle algorithm generates trajectories isomorphic to those generated by molecular dynamics. The shear moduli were evaluated based on molecular dynamics calculations for the three weighting functions, B spline, Lucy, and Cusp functions. The accuracy and applicability of the methods were estimated by comparing a set of smooth particle Rayleigh-Benard problems, all in the laminar regime, to corresponding highly-accurate grid-based numerical solutions of continuum equations. Both transient and stationary smooth particle solutions reproduce the grid-based data with velocity errors on the order of 5%. The smooth particle method still provides robust solutions at high Rayleigh number where grid-based methods fails.
Manual tracking enhances smooth pursuit eye movements.
Niehorster, Diederick C; Siu, Wilfred W F; Li, Li
2015-01-01
Previous studies have reported that concurrent manual tracking enhances smooth pursuit eye movements only when tracking a self-driven or a predictable moving target. Here, we used a control-theoretic approach to examine whether concurrent manual tracking enhances smooth pursuit of an unpredictable moving target. In the eye-hand tracking condition, participants used their eyes to track a Gaussian target that moved randomly along a horizontal axis. In the meantime, they used their dominant hand to move a mouse to control the horizontal movement of a Gaussian cursor to vertically align it with the target. In the eye-alone tracking condition, the target and cursor positions recorded in the eye-hand tracking condition were replayed, and participants only performed eye tracking of the target. Catch-up saccades were identified and removed from the recorded eye movements, allowing for a frequency-response analysis of the smooth pursuit response to unpredictable target motion. We found that the overall smooth pursuit gain was higher and the number of catch-up saccades made was less when eye tracking was accompanied by manual tracking than when not. We conclude that concurrent manual tracking enhances smooth pursuit. This enhancement is a fundamental property of eye-hand coordination that occurs regardless of the predictability of the target motion.
Interstitial Cells: Regulators of Smooth Muscle Function
Sanders, Kenton M.; Ward, Sean M.; Koh, Sang Don
2014-01-01
Smooth muscles are complex tissues containing a variety of cells in addition to muscle cells. Interstitial cells of mesenchymal origin interact with and form electrical connectivity with smooth muscle cells in many organs, and these cells provide important regulatory functions. For example, in the gastrointestinal tract, interstitial cells of Cajal (ICC) and PDGFRα+ cells have been described, in detail, and represent distinct classes of cells with unique ultrastructure, molecular phenotypes, and functions. Smooth muscle cells are electrically coupled to ICC and PDGFRα+ cells, forming an integrated unit called the SIP syncytium. SIP cells express a variety of receptors and ion channels, and conductance changes in any type of SIP cell affect the excitability and responses of the syncytium. SIP cells are known to provide pacemaker activity, propagation pathways for slow waves, transduction of inputs from motor neurons, and mechanosensitivity. Loss of interstitial cells has been associated with motor disorders of the gut. Interstitial cells are also found in a variety of other smooth muscles; however, in most cases, the physiological and pathophysiological roles for these cells have not been clearly defined. This review describes structural, functional, and molecular features of interstitial cells and discusses their contributions in determining the behaviors of smooth muscle tissues. PMID:24987007
On the Absolutely Continuous Spectrum of Stark Operators
Perelman, Galina
The stability of the absolutely continuous spectrum of the one-dimensional Stark operator under perturbations of the potential is discussed. The focus is on proving this stability under minimal assumptions on smoothness of the perturbation. A general criterion is presented together with some applications. These include the case of periodic perturbations where we show that any perturbation vL1()∩H-1/2() preserves the a.c. spectrum.
Smooth muscle actin and myosin expression in cultured airway smooth muscle cells.
Wong, J Z; Woodcock-Mitchell, J; Mitchell, J; Rippetoe, P; White, S; Absher, M; Baldor, L; Evans, J; McHugh, K M; Low, R B
1998-05-01
In this study, the expression of smooth muscle actin and myosin was examined in cultures of rat tracheal smooth muscle cells. Protein and mRNA analyses demonstrated that these cells express alpha- and gamma-smooth muscle actin and smooth muscle myosin and nonmuscle myosin-B heavy chains. The expression of the smooth muscle specific actin and myosin isoforms was regulated in the same direction when growth conditions were changed. Thus, at confluency in 1 or 10% serum-containing medium as well as for low-density cells (50-60% confluent) deprived of serum, the expression of the smooth muscle forms of actin and myosin was relatively high. Conversely, in rapidly proliferating cultures at low density in 10% serum, smooth muscle contractile protein expression was low. The expression of nonmuscle myosin-B mRNA and protein was more stable and was upregulated only to a small degree in growing cells. Our results provide new insight into the molecular basis of differentiation and contractile function in airway smooth muscle cells.
Cardiac, Skeletal, and smooth muscle mitochondrial respiration
DEFF Research Database (Denmark)
Park, Song-Young; Gifford, Jayson R; Andtbacka, Robert H I
2014-01-01
, skeletal, and smooth muscle was harvested from a total of 22 subjects (53±6 yrs) and mitochondrial respiration assessed in permeabilized fibers. Complex I+II, state 3 respiration, an index of oxidative phosphorylation capacity, fell progressively from cardiac, skeletal, to smooth muscle (54±1; 39±4; 15......±1 pmol•s(-1)•mg (-1), pindex of mitochondrial density, also fell progressively from cardiac, skeletal, to smooth muscle (222±13; 115±2; 48±2 umol•g(-1)•min(-1), p... per mitochondrial content), oxidative phosphorylation capacity was no longer different between the three muscle types. Interestingly, Complex I state 2 normalized for CS activity, an index of non-phosphorylating respiration per mitochondrial content, increased progressively from cardiac, skeletal...
Smoothing of Fused Spectral Consistent Satellite Images
DEFF Research Database (Denmark)
Sveinsson, Johannes; Aanæs, Henrik; Benediktsson, Jon Atli
2006-01-01
Several widely used methods have been proposed for fusing high resolution panchromatic data and lower resolution multi-channel data. However, many of these methods fail to maintain spectral consistency of the fused high resolution image, which is of high importance to many of the applications based...... in a statistically meaningful way. The fusion method was called spectral consistent panshapen- ing (SC) and it was shown that spectral consistency was a direct consequence of imaging physics and hence guaranteed by the SCP. In this paper exploit this framework and investigate two smoothing methods of the fused image...... obtain by SCP. The first smoothing method is based on Markov random field (MRF) model, while the second method uses wavelet domain hidden Markov models (HMM) for smoothing of the SCP fused image....
Multiple predictor smoothing methods for sensitivity analysis.
Energy Technology Data Exchange (ETDEWEB)
Helton, Jon Craig; Storlie, Curtis B.
2006-08-01
The use of multiple predictor smoothing methods in sampling-based sensitivity analyses of complex models is investigated. Specifically, sensitivity analysis procedures based on smoothing methods employing the stepwise application of the following nonparametric regression techniques are described: (1) locally weighted regression (LOESS), (2) additive models, (3) projection pursuit regression, and (4) recursive partitioning regression. The indicated procedures are illustrated with both simple test problems and results from a performance assessment for a radioactive waste disposal facility (i.e., the Waste Isolation Pilot Plant). As shown by the example illustrations, the use of smoothing procedures based on nonparametric regression techniques can yield more informative sensitivity analysis results than can be obtained with more traditional sensitivity analysis procedures based on linear regression, rank regression or quadratic regression when nonlinear relationships between model inputs and model predictions are present.
ibr: Iterative bias reduction multivariate smoothing
Energy Technology Data Exchange (ETDEWEB)
Hengartner, Nicholas W [Los Alamos National Laboratory; Cornillon, Pierre-andre [AGRO-SUP, FRANCE; Matzner - Lober, Eric [RENNES 2, FRANCE
2009-01-01
Regression is a fundamental data analysis tool for relating a univariate response variable Y to a multivariate predictor X {element_of} E R{sup d} from the observations (X{sub i}, Y{sub i}), i = 1,...,n. Traditional nonparametric regression use the assumption that the regression function varies smoothly in the independent variable x to locally estimate the conditional expectation m(x) = E[Y|X = x]. The resulting vector of predicted values {cflx Y}{sub i} at the observed covariates X{sub i} is called a regression smoother, or simply a smoother, because the predicted values {cflx Y}{sub i} are less variable than the original observations Y{sub i}. Linear smoothers are linear in the response variable Y and are operationally written as {cflx m} = X{sub {lambda}}Y, where S{sub {lambda}} is a n x n smoothing matrix. The smoothing matrix S{sub {lambda}} typically depends on a tuning parameter which we denote by {lambda}, and that governs the tradeoff between the smoothness of the estimate and the goodness-of-fit of the smoother to the data by controlling the effective size of the local neighborhood over which the responses are averaged. We parameterize the smoothing matrix such that large values of {lambda} are associated to smoothers that averages over larger neighborhood and produce very smooth curves, while small {lambda} are associated to smoothers that average over smaller neighborhood to produce a more wiggly curve that wants to interpolate the data. The parameter {lambda} is the bandwidth for kernel smoother, the span size for running-mean smoother, bin smoother, and the penalty factor {lambda} for spline smoother.
Local smoothness for global optical flow
DEFF Research Database (Denmark)
Rakêt, Lars Lau
2012-01-01
by this technique and work on local-global optical flow we propose a simple method for fusing optical flow estimates of different smoothness by evaluating interpolation quality locally by means of L1 block match on the corresponding set of gradient images. We illustrate the method in a setting where optical flows...... are estimated by a TV-L1 energy. On average this procedure reduces the average endpoint error by 15% over flows estimated using the OPP, and gives flow fields that are consistently better than the single best flows with a fixed smoothness parameter....
Production of super-smooth articles
Energy Technology Data Exchange (ETDEWEB)
Duchane, D.V.
1981-05-29
Super-smooth rounded or formed articles made of thermoplastic materials including various poly(methyl methacrylate) or acrylonitrile-butadiene-styrene copolymers are produced by immersing the articles into a bath, the composition of which is slowly changed with time. The starting composition of the bath is made up of at least one solvent for the polymer and a diluent made up of at least one nonsolvent for the polymer and optional materials which are soluble in the bath. The resulting extremely smooth articles are useful as mandrels for laser fusion and should be useful for a wide variety of other purposes, for example lenses.
Analysis of Two Advanced Smoothing Algorithms.
1985-09-01
equations 1.3 19 - and 1.4. The problem with this method is that the smoothing program may have to be run several times with each run containing a...uruie 48iOsragtln thog pont in wido Fi I ..ea .n to enpont an eta on :7-" - - . . . .I SUNIXY NC.1.XSZ O (3.10) For each I=1, ., (MNWNSZ-1), the right...smoothed point values were plotted, the plot would show too many peaks and would appear very jagged. In order to alleviate this problem , these
Autophagic regulation of smooth muscle cell biology
Directory of Open Access Journals (Sweden)
Joshua K. Salabei
2015-04-01
Full Text Available Autophagy regulates the metabolism, survival, and function of numerous cell types, including those comprising the cardiovascular system. In the vasculature, changes in autophagy have been documented in atherosclerotic and restenotic lesions and in hypertensive vessels. The biology of vascular smooth muscle cells appears particularly sensitive to changes in the autophagic program. Recent evidence indicates that stimuli or stressors evoked during the course of vascular disease can regulate autophagic activity, resulting in modulation of VSMC phenotype and viability. In particular, certain growth factors and cytokines, oxygen tension, and pharmacological drugs have been shown to trigger autophagy in smooth muscle cells. Importantly, each of these stimuli has a redox component, typically associated with changes in the abundance of reactive oxygen, nitrogen, or lipid species. Collective findings support the hypothesis that autophagy plays a critical role in vascular remodeling by regulating smooth muscle cell phenotype transitions and by influencing the cellular response to stress. In this graphical review, we summarize current knowledge on the role of autophagy in the biology of the smooth muscle cell in (pathophysiology.
Interval Forecast for Smooth Transition Autoregressive Model ...
African Journals Online (AJOL)
In this paper, we propose a simple method for constructing interval forecast for smooth transition autoregressive (STAR) model. This interval forecast is based on bootstrapping the residual error of the estimated STAR model for each forecast horizon and computing various Akaike information criterion (AIC) function. This new ...
Full Waveform Inversion Using Nonlinearly Smoothed Wavefields
Li, Y.
2017-05-26
The lack of low frequency information in the acquired data makes full waveform inversion (FWI) conditionally converge to the accurate solution. An initial velocity model that results in data with events within a half cycle of their location in the observed data was required to converge. The multiplication of wavefields with slightly different frequencies generates artificial low frequency components. This can be effectively utilized by multiplying the wavefield with itself, which is nonlinear operation, followed by a smoothing operator to extract the artificially produced low frequency information. We construct the objective function using the nonlinearly smoothed wavefields with a global-correlation norm to properly handle the energy imbalance in the nonlinearly smoothed wavefield. Similar to the multi-scale strategy, we progressively reduce the smoothing width applied to the multiplied wavefield to welcome higher resolution. We calculate the gradient of the objective function using the adjoint-state technique, which is similar to the conventional FWI except for the adjoint source. Examples on the Marmousi 2 model demonstrate the feasibility of the proposed FWI method to mitigate the cycle-skipping problem in the case of a lack of low frequency information.
Smooth rank one perturbations of selfadjoint operators
Hassi, Seppo; Snoo, H.S.V. de; Willemsma, A.D.I.
Let A be a selfadjoint operator in a Hilbert space aleph with inner product [.,.]. The rank one perturbations of A have the form A+tau [.,omega]omega, tau epsilon R, for some element omega epsilon aleph. In this paper we consider smooth perturbations, i.e. we consider omega epsilon dom \\A\\(k/2) for
Role of Smooth Muscle in Intestinal Inflammation
Directory of Open Access Journals (Sweden)
Stephen M Collins
1996-01-01
Full Text Available The notion that smooth muscle function is altered in inflammation is prompted by clinical observations of altered motility in patients with inflammatory bowel disease (IBD. While altered motility may reflect inflammation-induced changes in intrinsic or extrinsic nerves to the gut, changes in gut hormone release and changes in muscle function, recent studies have provided in vitro evidence of altered muscle contractility in muscle resected from patients with ulcerative colitis or Crohn’s disease. In addition, the observation that smooth muscle cells are more numerous and prominent in the strictured bowel of IBD patients compared with controls suggests that inflammation may alter the growth of intestinal smooth muscle. Thus, inflammation is associated with changes in smooth muscle growth and contractility that, in turn, contribute to important symptoms of IBD including diarrhea (from altered motility and pain (via either altered motility or stricture formation. The involvement of smooth muscle in this context may be as an innocent bystander, where cells and products of the inflammatory process induce alterations in muscle contractility and growth. However, it is likely that intestinal muscle cells play a more active role in the inflammatory process via the elaboration of mediators and trophic factors, including cytokines, and via the production of collagen. The concept of muscle cells as active participants in the intestinal inflammatory process is a new concept that is under intense study. This report summarizes current knowledge as it relates to these two aspects of altered muscle function (growth and contractility in the inflamed intestine, and will focus on mechanisms underlying these changes, based on data obtained from animal models of intestinal inflammation.
Analytic continuation average spectrum method for transport in quantum liquids
Energy Technology Data Exchange (ETDEWEB)
Kletenik-Edelman, Orly [School of Chemistry, Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel); Rabani, Eran, E-mail: rabani@tau.ac.il [School of Chemistry, Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel); Reichman, David R. [Department of Chemistry, Columbia University, 3000 Broadway, New York, NY 10027 (United States)
2010-05-12
Recently, we have applied the analytic continuation averaged spectrum method (ASM) to calculate collective density fluctuations in quantum liquid . Unlike the maximum entropy (MaxEnt) method, the ASM approach is capable of revealing resolved modes in the dynamic structure factor in agreement with experiments. In this work we further develop the ASM to study single-particle dynamics in quantum liquids with dynamical susceptibilities that are characterized by a smooth spectrum. Surprisingly, we find that for the power spectrum of the velocity autocorrelation function there are pronounced differences in comparison with the MaxEnt approach, even for this simple case of smooth unimodal dynamic response. We show that for liquid para-hydrogen the ASM is closer to the centroid molecular dynamics (CMD) result while for normal liquid helium it agrees better with the quantum mode coupling theory (QMCT) and with the MaxEnt approach.
Semiparametric smoothing of discrete failure time data.
Patil, Prakash N; Bagkavos, Dimitrios
2012-01-01
An estimator of the hazard rate function from discrete failure time data is obtained by semiparametric smoothing of the (nonsmooth) maximum likelihood estimator, which is achieved by repeated multiplication of a Markov chain transition-type matrix. This matrix is constructed so as to have a given standard discrete parametric hazard rate model, termed the vehicle model, as its stationary hazard rate. As with the discrete density estimation case, the proposed estimator gives improved performance when the vehicle model is a good one and otherwise provides a nonparametric method comparable to the only purely nonparametric smoother discussed in the literature. The proposed semiparametric smoothing approach is then extended to hazard models with covariates and is illustrated by applications to simulated and real data sets. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Tame geometry with application in smooth analysis
Yomdin, Yosef
2004-01-01
The Morse-Sard theorem is a rather subtle result and the interplay between the high-order analytic structure of the mappings involved and their geometry rarely becomes apparent. The main reason is that the classical Morse-Sard theorem is basically qualitative. This volume gives a proof and also an "explanation" of the quantitative Morse-Sard theorem and related results, beginning with the study of polynomial (or tame) mappings. The quantitative questions, answered by a combination of the methods of real semialgebraic and tame geometry and integral geometry, turn out to be nontrivial and highly productive. The important advantage of this approach is that it allows the separation of the role of high differentiability and that of algebraic geometry in a smooth setting: all the geometrically relevant phenomena appear already for polynomial mappings. The geometric properties obtained are "stable with respect to approximation", and can be imposed on smooth functions via polynomial approximation.
Cortex phellodendri Extract Relaxes Airway Smooth Muscle
Qiu-Ju Jiang; Weiwei Chen; Hong Dan; Li Tan; He Zhu; Guangzhong Yang; Jinhua Shen; Yong-Bo Peng; Ping Zhao; Lu Xue; Meng-Fei Yu; Liqun Ma; Xiao-Tang Si; Zhuo Wang; Jiapei Dai
2016-01-01
Cortex phellodendri is used to reduce fever and remove dampness and toxin. Berberine is an active ingredient of C. phellodendri. Berberine from Argemone ochroleuca can relax airway smooth muscle (ASM); however, whether the nonberberine component of C. phellodendri has similar relaxant action was unclear. An n-butyl alcohol extract of C. phellodendri (NBAECP, nonberberine component) was prepared, which completely inhibits high K+- and acetylcholine- (ACH-) induced precontraction of airway smoo...
On the thermodynamics of smooth muscle contraction
Stålhand, Jonas; McMeeking, Robert M.; Holzapfel, Gerhard A.
2016-09-01
Cell function is based on many dynamically complex networks of interacting biochemical reactions. Enzymes may increase the rate of only those reactions that are thermodynamically consistent. In this paper we specifically treat the contraction of smooth muscle cells from the continuum thermodynamics point of view by considering them as an open system where matter passes through the cell membrane. We systematically set up a well-known four-state kinetic model for the cross-bridge interaction of actin and myosin in smooth muscle, where the transition between each state is driven by forward and reverse reactions. Chemical, mechanical and energy balance laws are provided in local forms, while energy balance is also formulated in the more convenient temperature form. We derive the local (non-negative) production of entropy from which we deduce the reduced entropy inequality and the constitutive equations for the first Piola-Kirchhoff stress tensor, the heat flux, the ion and molecular flux and the entropy. One example for smooth muscle contraction is analyzed in more detail in order to provide orientation within the established general thermodynamic framework. In particular the stress evolution, heat generation, muscle shorting rate and a condition for muscle cooling are derived.
Intercellular ultrafast Ca2+ wave in vascular smooth muscle cells: numerical and experimental study
Quijano, J. C.; Raynaud, F.; Nguyen, D.; Piacentini, N.; Meister, J. J.
2016-08-01
Vascular smooth muscle cells exhibit intercellular Ca2+ waves in response to local mechanical or KCl stimulation. Recently, a new type of intercellular Ca2+ wave was observed in vitro in a linear arrangement of smooth muscle cells. The intercellular wave was denominated ultrafast Ca2+ wave and it was suggested to be the result of the interplay between membrane potential and Ca2+ dynamics which depended on influx of extracellular Ca2+, cell membrane depolarization and its intercel- lular propagation. In the present study we measured experimentally the conduction velocity of the membrane depolarization and performed simulations of the ultrafast Ca2+ wave along coupled smooth muscle cells. Numerical results reproduced a wide spectrum of experimental observations, including Ca2+ wave velocity, electrotonic membrane depolarization along the network, effects of inhibitors and independence of the Ca2+ wave speed on the intracellular stores. The numerical data also provided new physiological insights suggesting ranges of crucial model parameters that may be altered experimentally and that could significantly affect wave kinetics allowing the modulation of the wave characteristics experimentally. Numerical and experimental results supported the hypothesis that the propagation of membrane depolarization acts as an intercellular messenger mediating intercellular ultrafast Ca2+ waves in smooth muscle cells.
How Do Families Smooth Household Heads` Earnings Volatility?
National Research Council Canada - National Science Library
Ki Seong Park;
2010-01-01
...` earnings is almost entirely smoothed. The most effective measure of smoothing heads` earnings volatility is income from self-employment, with the next most effective being labor income of other family members...
Smoothed nonparametric estimation for current status competing risks data
Chenxi Li; Jason P. Fine
2013-01-01
We study the nonparametric estimation of the cumulative incidence function and the cause-specific hazard function for current status data with competing risks via kernel smoothing. A smoothed naive nonparametric maximum likelihood estimator and a smoothed full nonparametric maximum likelihood estimator are shown to have pointwise asymptotic normality and faster convergence rates than the corresponding unsmoothed nonparametric likelihood estimators. Using the smoothed estimators and the plug-i...
Smooth Fano polytopes can not be inductively constructed
DEFF Research Database (Denmark)
Øbro, Mikkel
2008-01-01
We examine a concrete smooth Fano 5-polytope $P$ with 8 vertices with the following properties: There does not exist a smooth Fano 5-polytope $Q$ with 7 vertices such that $P$ contains $Q$, and there does not exist a smooth Fano 5-polytope $R$ with 9 vertices such that $R$ contains $P$. As the po...
Smoothed Analysis for the Conjugate Gradient Algorithm
Menon, Govind; Trogdon, Thomas
2016-11-01
The purpose of this paper is to establish bounds on the rate of convergence of the conjugate gradient algorithm when the underlying matrix is a random positive definite perturbation of a deterministic positive definite matrix. We estimate all finite moments of a natural halting time when the random perturbation is drawn from the Laguerre unitary ensemble in a critical scaling regime explored in Deift et al. (2016). These estimates are used to analyze the expected iteration count in the framework of smoothed analysis, introduced by Spielman and Teng (2001). The rigorous results are compared with numerical calculations in several cases of interest.
Smooth leading edge transition in hypersonic flow
Energy Technology Data Exchange (ETDEWEB)
Gaillard, L.; Benard, E.; Alziary de Roquefort, T. [CEAT, Poitiers (France). Lab. d`Etudes Aerodynamiques
1999-01-01
The boundary layer transition along the attachment line of a smooth swept circular cylinder in hypersonic flow is investigated in a blowdown wind tunnel. A wide range of spanwise Mach numbers Me (3.28 to 6.78) is covered with the help of different models at several sweep angles (60 {<=}{Lambda}{<=}80 ). The transition is indirectly detected by means of heat flux measurements. The influence of the wall to stagnation temperature ratio is investigated by cooling the model with liquid nitrogen. (orig.) With 9 figs., 2 tabs., 30 refs.
Vestibular activation, smooth pursuit tracking, and psychosis.
Jones, A M; Pivik, R T
1985-04-01
Pursuit tracking and vestibular activation procedures were combined in an investigation to determine if smooth pursuit tracking deficits could be related to abnormalities of visual-vestibular interaction in psychiatric patients. In actively psychotic patients, but not in comparison groups of schizophrenic outpatients with remitted symptomatology or normal controls, a significant failure of visual fixation to suppress caloric nystagmus was related to a higher incidence of disordered tracking during both baseline and postirrigation conditions. Other vestibular irregularities including dysrhythmia and reduced fast phase velocity were observed in these same patients. The results are supportive of a central deficit in visual-vestibular interaction that may contribute to pursuit tracking deficits in psychosis.
Smooth Nanowire/Polymer Composite Transparent Electrodes
Gaynor, Whitney
2011-04-29
Smooth composite transparent electrodes are fabricated via lamination of silver nanowires into the polymer poly-(4,3-ethylene dioxythiophene): poly(styrene-sulfonate) (PEDOT:PSS). The surface roughness is dramatically reduced compared to bare nanowires. High-efficiency P3HT:PCBM organic photovoltaic cells can be fabricated using these composites, reproducing the performance of cells on indium tin oxide (ITO) on glass and improving the performance of cells on ITO on plastic. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Smooth nanowire/polymer composite transparent electrodes
Energy Technology Data Exchange (ETDEWEB)
Gaynor, Whitney; McGehee, Michael D. [Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305 (United States); Burkhard, George F. [Department of Applied Physics, Stanford University, Stanford, CA 94305 (United States); Peumans, Peter [Department of Electrical Engineering, Stanford University, Stanford, CA 94305 (United States)
2011-07-12
Smooth composite transparent electrodes are fabricated via lamination of silver nanowires into the polymer poly-(4,3-ethylene dioxythiophene):poly(styrene-sulfonate) (PEDOT:PSS). The surface roughness is dramatically reduced compared to bare nanowires. High-efficiency P3HT:PCBM organic photovoltaic cells can be fabricated using these composites, reproducing the performance of cells on indium tin oxide (ITO) on glass and improving the performance of cells on ITO on plastic. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Peinke, J.; Parisi, J.; Röhricht, B.; Rössler, O. E.; Metzler, W.
1988-01-01
Generalized Mandelbrot sets arise in perturbed (non-analytic) versions of the complex logistic map. Numerically, it contains smooth portions as shown previously. To exclude that this result is specific to particular initial conditions only, the structure of the analogue to the Fatou set is looked at in the region in question. The set of non-divergent points is being "eaten up" by a smooth invading boundary. Therefore, the same type of decomposition applies independent of position in parameter space, in the region in question.
Autism spectrum disorder (ASD) is a neurological and developmental disorder that begins early in childhood and lasts throughout a person's life. ... be known as Asperger syndrome and pervasive developmental disorders. It is called a "spectrum" disorder because people ...
Coupling of smooth particle hydrodynamics with PRONTO
Energy Technology Data Exchange (ETDEWEB)
Attaway, S.W.; Heinstein, M.W.; Mello, F.J.; Swegle, J.W.
1993-08-01
A gridless numerical technique called smooth particle hydrodynamics (SPH) has been coupled to the transient dynamics finite element code, PRONTO. In this paper, a new weighted residual derivation for the SPH method will be presented, and the methods used to embed SPH within PRONTO will be outlined. Example SPH-PRONTO calculations will also be presented. One major difficulty associated with the Lagrangian finite element method is modeling materials with no shear strength; for example, gases, fluids and explosive bi-products. Typically these materials can be modeled for only a short time with a Lagrangian finite element code. Large distortions cause tangling of the mesh, which will eventually lead to numerical difficulties such as negative element area or ``bow tie`` elements. Remeshing will allow the problem to continue for a short while, but the large distortions can prevent a complete analysis. Smooth particle hydrodynamics is a gridless Lagrangian technique. Requiring no mesh, SPH has the potential to model material fracture, large shear flows, and penetration. SPH computes the strain rate and the stress divergence based on the nearest neighbors of a particle, which are determined using an efficient particle sorting technique. Embedding the SPH method within PRONTO allows part of the problem to be modeled with quadrilateral finite elements while other parts are modeled with the gridless SPH method. SPH elements are coupled to the quadrilateral elements through a contact like algorithm.
Cortex phellodendri Extract Relaxes Airway Smooth Muscle
Directory of Open Access Journals (Sweden)
Qiu-Ju Jiang
2016-01-01
Full Text Available Cortex phellodendri is used to reduce fever and remove dampness and toxin. Berberine is an active ingredient of C. phellodendri. Berberine from Argemone ochroleuca can relax airway smooth muscle (ASM; however, whether the nonberberine component of C. phellodendri has similar relaxant action was unclear. An n-butyl alcohol extract of C. phellodendri (NBAECP, nonberberine component was prepared, which completely inhibits high K+- and acetylcholine- (ACH- induced precontraction of airway smooth muscle in tracheal rings and lung slices from control and asthmatic mice, respectively. The contraction induced by high K+ was also blocked by nifedipine, a selective blocker of L-type Ca2+ channels. The ACH-induced contraction was partially inhibited by nifedipine and pyrazole 3, an inhibitor of TRPC3 and STIM/Orai channels. Taken together, our data demonstrate that NBAECP can relax ASM by inhibiting L-type Ca2+ channels and TRPC3 and/or STIM/Orai channels, suggesting that NBAECP could be developed to a new drug for relieving bronchospasm.
Cortex phellodendri Extract Relaxes Airway Smooth Muscle
Jiang, Qiu-Ju; Chen, Weiwei; Dan, Hong; Tan, Li; Zhu, He; Yang, Guangzhong; Shen, Jinhua; Peng, Yong-Bo; Zhao, Ping; Xue, Lu; Yu, Meng-Fei; Ma, Liqun; Si, Xiao-Tang; Wang, Zhuo; Dai, Jiapei; Qin, Gangjian; Zou, Chunbin; Liu, Qing-Hua
2016-01-01
Cortex phellodendri is used to reduce fever and remove dampness and toxin. Berberine is an active ingredient of C. phellodendri. Berberine from Argemone ochroleuca can relax airway smooth muscle (ASM); however, whether the nonberberine component of C. phellodendri has similar relaxant action was unclear. An n-butyl alcohol extract of C. phellodendri (NBAECP, nonberberine component) was prepared, which completely inhibits high K+- and acetylcholine- (ACH-) induced precontraction of airway smooth muscle in tracheal rings and lung slices from control and asthmatic mice, respectively. The contraction induced by high K+ was also blocked by nifedipine, a selective blocker of L-type Ca2+ channels. The ACH-induced contraction was partially inhibited by nifedipine and pyrazole 3, an inhibitor of TRPC3 and STIM/Orai channels. Taken together, our data demonstrate that NBAECP can relax ASM by inhibiting L-type Ca2+ channels and TRPC3 and/or STIM/Orai channels, suggesting that NBAECP could be developed to a new drug for relieving bronchospasm. PMID:27239213
REACTIVE POWER COMPENSATOR WITH SMOOTH CONTROL
Directory of Open Access Journals (Sweden)
V. V. Burlaka
2014-12-01
Full Text Available Reactive power compensation devices are widely used: thyristor-control reactors (TCR and thyristor-switched capacitors (TSC. The TCR disadvantages are discussed. The TSC disadvantages are: influence of higher harmonics on nonsinusoidal voltage power system, the inability to ensure the smooth regulation. The proposed reactive power compensator consists of series with active filter and capacitors with step switch. Reactive power compensator’s control system is proposed. Hysteretic control of the inverter with current feedback is applied. DC-voltage regulator provides balance of active power. The control system allows overcompensation or undercompensation of reactive power modes. Reactive power distribution regulator performs the redistribution of power between switching capacitors and active filter. Minimization condition of this regulator is active filter’s power. Adjustment properties of reactive power compensator are analyzed. The choice of relations between the capacitors TSC steps to minimize the installed capacity of the active filter and the number of stages in TSC is considered. The approach that makes possible to «isolate» capacitors from harmonic currents and provide smooth control of reactive power is proposed
Smooth manifold structure for extreme channels
Iten, Raban; Colbeck, Roger
2018-01-01
A quantum channel from a system A of dimension dA to a system B of dimension dB is a completely positive trace-preserving map from complex dA × dA to dB × dB matrices, and the set of all such maps with Kraus rank r has the structure of a smooth manifold. We describe this set in two ways. First, as a quotient space of (a subset of) the rdB × dA dimensional Stiefel manifold. Second, as the set of all Choi-states of a fixed rank r. These two descriptions are topologically equivalent. This allows us to show that the set of all Choi-states corresponding to extreme channels from system A to system B of a fixed Kraus rank r is a smooth submanifold of dimension 2 r dAdB-dA2-r2 of the set of all Choi-states of rank r. As an application, we derive a lower bound on the number of parameters required for a quantum circuit topology to be able to approximate all extreme channels from A to B arbitrarily well.
Raizada, Rajeev D S; Lee, Yune-Sang
2013-01-01
Spatial smoothness is helpful when averaging fMRI signals across multiple subjects, as it allows different subjects' corresponding brain areas to be pooled together even if they are slightly misaligned. However, smoothing is usually not applied when performing multivoxel pattern-based analyses (MVPA), as it runs the risk of blurring away the information that fine-grained spatial patterns contain. It would therefore be desirable, if possible, to carry out pattern-based analyses which take unsmoothed data as their input but which produce smooth images as output. We show here that the Gaussian Naive Bayes (GNB) classifier does precisely this, when it is used in "searchlight" pattern-based analyses. We explain why this occurs, and illustrate the effect in real fMRI data. Moreover, we show that analyses using GNBs produce results at the multi-subject level which are statistically robust, neurally plausible, and which replicate across two independent data sets. By contrast, SVM classifiers applied to the same data do not generate a replication, even if the SVM-derived searchlight maps have smoothing applied to them. An additional advantage of GNB classifiers for searchlight analyses is that they are orders of magnitude faster to compute than more complex alternatives such as SVMs. Collectively, these results suggest that Gaussian Naive Bayes classifiers may be a highly non-naive choice for multi-subject pattern-based fMRI studies.
Directory of Open Access Journals (Sweden)
Rajeev D S Raizada
Full Text Available Spatial smoothness is helpful when averaging fMRI signals across multiple subjects, as it allows different subjects' corresponding brain areas to be pooled together even if they are slightly misaligned. However, smoothing is usually not applied when performing multivoxel pattern-based analyses (MVPA, as it runs the risk of blurring away the information that fine-grained spatial patterns contain. It would therefore be desirable, if possible, to carry out pattern-based analyses which take unsmoothed data as their input but which produce smooth images as output. We show here that the Gaussian Naive Bayes (GNB classifier does precisely this, when it is used in "searchlight" pattern-based analyses. We explain why this occurs, and illustrate the effect in real fMRI data. Moreover, we show that analyses using GNBs produce results at the multi-subject level which are statistically robust, neurally plausible, and which replicate across two independent data sets. By contrast, SVM classifiers applied to the same data do not generate a replication, even if the SVM-derived searchlight maps have smoothing applied to them. An additional advantage of GNB classifiers for searchlight analyses is that they are orders of magnitude faster to compute than more complex alternatives such as SVMs. Collectively, these results suggest that Gaussian Naive Bayes classifiers may be a highly non-naive choice for multi-subject pattern-based fMRI studies.
Raizada, Rajeev D. S.; Lee, Yune-Sang
2013-01-01
Spatial smoothness is helpful when averaging fMRI signals across multiple subjects, as it allows different subjects' corresponding brain areas to be pooled together even if they are slightly misaligned. However, smoothing is usually not applied when performing multivoxel pattern-based analyses (MVPA), as it runs the risk of blurring away the information that fine-grained spatial patterns contain. It would therefore be desirable, if possible, to carry out pattern-based analyses which take unsmoothed data as their input but which produce smooth images as output. We show here that the Gaussian Naive Bayes (GNB) classifier does precisely this, when it is used in “searchlight” pattern-based analyses. We explain why this occurs, and illustrate the effect in real fMRI data. Moreover, we show that analyses using GNBs produce results at the multi-subject level which are statistically robust, neurally plausible, and which replicate across two independent data sets. By contrast, SVM classifiers applied to the same data do not generate a replication, even if the SVM-derived searchlight maps have smoothing applied to them. An additional advantage of GNB classifiers for searchlight analyses is that they are orders of magnitude faster to compute than more complex alternatives such as SVMs. Collectively, these results suggest that Gaussian Naive Bayes classifiers may be a highly non-naive choice for multi-subject pattern-based fMRI studies. PMID:23922740
An earthquake rate forecast for Europe based on smoothed seismicity and smoothed fault contribution
Hiemer, Stefan; Woessner, Jochen; Basili, Roberto; Wiemer, Stefan
2013-04-01
The main objective of project SHARE (Seismic Hazard Harmonization in Europe) is to develop a community-based seismic hazard model for the Euro-Mediterranean region. The logic tree of earthquake rupture forecasts comprises several methodologies including smoothed seismicity approaches. Smoothed seismicity thus represents an alternative concept to express the degree of spatial stationarity of seismicity and provides results that are more objective, reproducible, and testable. Nonetheless, the smoothed-seismicity approach suffers from the common drawback of being generally based on earthquake catalogs alone, i.e. the wealth of knowledge from geology is completely ignored. We present a model that applies the kernel-smoothing method to both past earthquake locations and slip rates on mapped crustal faults and subductions. The result is mainly driven by the data, being independent of subjective delineation of seismic source zones. The core parts of our model are two distinct location probability densities: The first is computed by smoothing past seismicity (using variable kernel smoothing to account for varying data density). The second is obtained by smoothing fault moment rate contributions. The fault moment rates are calculated by summing the moment rate of each fault patch on a fully parameterized and discretized fault as available from the SHARE fault database. We assume that the regional frequency-magnitude distribution of the entire study area is well known and estimate the a- and b-value of a truncated Gutenberg-Richter magnitude distribution based on a maximum likelihood approach that considers the spatial and temporal completeness history of the seismic catalog. The two location probability densities are linearly weighted as a function of magnitude assuming that (1) the occurrence of past seismicity is a good proxy to forecast occurrence of future seismicity and (2) future large-magnitude events occur more likely in the vicinity of known faults. Consequently
Smooth Transitions: Helping Students with Autism Spectrum Disorder Navigate the School Day
Hume, Kara; Sreckovic, Melissa; Snyder, Kate; Carnahan, Christina R.
2014-01-01
In school, students are expected to navigate different types of transitions every day, including those between instructors, subjects, and instructional formats, as well as classrooms. Despite the routines that many teachers develop to facilitate efficient transitions and maximize instructional time, many learners with ASD continue to struggle with…
An analysis of smoothed particle hydrodynamics
Energy Technology Data Exchange (ETDEWEB)
Swegle, J.W.; Attaway, S.W.; Heinstein, M.W.; Mello, F.J. [Sandia National Labs., Albuquerque, NM (United States); Hicks, D.L. [Michigan Technological Univ., Houghton, MI (United States)
1994-03-01
SPH (Smoothed Particle Hydrodynamics) is a gridless Lagrangian technique which is appealing as a possible alternative to numerical techniques currently used to analyze high deformation impulsive loading events. In the present study, the SPH algorithm has been subjected to detailed testing and analysis to determine its applicability in the field of solid dynamics. An important result of the work is a rigorous von Neumann stability analysis which provides a simple criterion for the stability or instability of the method in terms of the stress state and the second derivative of the kernel function. Instability, which typically occurs only for solids in tension, results not from the numerical time integration algorithm, but because the SPH algorithm creates an effective stress with a negative modulus. The analysis provides insight into possible methods for removing the instability. Also, SPH has been coupled into the transient dynamics finite element code PRONTO, and a weighted residual derivation of the SPH equations has been obtained.
Clip art rendering of smooth isosurfaces.
Stroila, Matei; Eisemann, Elmar; Hart, John
2008-01-01
Clip art is a simplified illustration form consisting of layered filled polygons or closed curves used to convey 3D shape information in a 2D vector graphics format. This paper focuses on the problem of direct conversion of smooth surfaces, ranging from the free-form shapes of art and design to the mathematical structures of geometry and topology, into a clip art form suitable for illustration use in books, papers and presentations. We show how to represent silhouette, shadow, gleam and other surface feature curves as the intersection of implicit surfaces, and derive equations for their efficient interrogation via particle chains. We further describe how to sort, orient, identify and fill the closed regions that overlay to form clip art. We demonstrate the results with numerous renderings used to illustrate the paper itself.
On the dynamic smoothing of mountains
Bonetti, S.; Porporato, A.
2017-06-01
After their formation, mountainous landscapes gradually evolve toward smoother geometries controlled by the interplay of erosion and sedimentation. The statistical mechanical properties of this process and the link between topography and geology have remained largely unexplored. We analyze the slope statistics of different mountains worldwide, showing that landscape age is fingerprinted in their distribution tails. Data reveal a universal relaxation process, through an algebraic decay progressively replaced by an exponential one, with exponents described by a global monotonic function. We then investigate the dominant components of this dynamic smoothing using a landscape evolution model, showing that the time evolution of slope statistics results from a delicate balance between diffusive soil creep, noise, and advective river incision, with the relaxation phase mainly dominated by diffusion. Results may suggest ways to formulate reduced order topographic evolution models for geomorphological and climatological applications, and to explore similarities in surface evolution in different contexts.
Video tonal stabilization via color states smoothing.
Wang, Yinting; Tao, Dacheng; Li, Xiang; Song, Mingli; Bu, Jiajun; Tan, Ping
2014-11-01
We address the problem of removing video color tone jitter that is common in amateur videos recorded with hand-held devices. To achieve this, we introduce color state to represent the exposure and white balance state of a frame. The color state of each frame can be computed by accumulating the color transformations of neighboring frame pairs. Then, the tonal changes of the video can be represented by a time-varying trajectory in color state space. To remove the tone jitter, we smooth the original color state trajectory by solving an L1 optimization problem with PCA dimensionality reduction. In addition, we propose a novel selective strategy to remove small tone jitter while retaining extreme exposure and white balance changes to avoid serious artifacts. Quantitative evaluation and visual comparison with previous work demonstrate the effectiveness of our tonal stabilization method. This system can also be used as a preprocessing tool for other video editing methods.
Adaptively Smoothed Seismicity Earthquake Forecasts for Italy
Werner, M J; Jackson, D D; Kagan, Y Y; Wiemer, S
2010-01-01
We present a model for estimating the probabilities of future earthquakes of magnitudes m > 4.95 in Italy. The model, a slightly modified version of the one proposed for California by Helmstetter et al. (2007) and Werner et al. (2010), approximates seismicity by a spatially heterogeneous, temporally homogeneous Poisson point process. The temporal, spatial and magnitude dimensions are entirely decoupled. Magnitudes are independently and identically distributed according to a tapered Gutenberg-Richter magnitude distribution. We estimated the spatial distribution of future seismicity by smoothing the locations of past earthquakes listed in two Italian catalogs: a short instrumental catalog and a longer instrumental and historical catalog. The bandwidth of the adaptive spatial kernel is estimated by optimizing the predictive power of the kernel estimate of the spatial earthquake density in retrospective forecasts. When available and trustworthy, we used small earthquakes m>2.95 to illuminate active fault structur...
Numerical quadrature over smooth surfaces with boundaries
Reeger, Jonah A.; Fornberg, Bengt
2018-02-01
This paper describes a high order accurate method to calculate integrals over curved surfaces with boundaries. Given data locations that are arbitrarily distributed over the surface, together with some functional description of the surface and its boundary, the algorithm produces matching quadrature weights. This extends on the authors' earlier methods for integrating over the surface of a sphere and over arbitrarily shaped smooth closed surfaces by also considering domain boundaries. The core approach consists again of combining RBF-FD (radial basis function-generated finite difference) approximations for curved surface triangles, which together make up the full surface. The provided examples include both curved and flat domains. In the highly special case of equi-spaced nodes over a regular interval in 1-D, the method provides a new opportunity for improving on the classical Gregory enhancements of the trapezoidal rule.
Smooth Pursuit of Flicker-Defined Motion
Mulligan, Jeffrey B.; Stevenson, Scott B.
2014-01-01
We examined the pursuit response to stimuli defined by space-variant flicker of a dense random dot carrier pattern. On each frame, every element of the pattern could change polarity, with a probability given by a two-dimensional Gaussian distribution. A normal distribution produces a circular region of twinkle, while inverting the distribution results in a spot of static texture in a twinkling surround. In this latter case, the carrier texture could be stationary, or could move with the twinkle modulator, thereby producing first-order motion in the region of the spot. While the twinkle-defined spot produces a strong sensation of motion, the complementary stimulus defined by the absence of twinkle does not, when viewed peripherally, it appears to move in steps even when the generating distribution moves smoothly. We examined pursuit responses to these stimuli using two techniques: 1) the eye movement correlogram, obtained by cross-correlating eye velocity with the velocity of a randomly-moving stimulus; and 2) delayed visual feedback, where transient stabilization of a target can produce spontaneous oscillations of the eye, with a period empirically observed to vary linearly with the applied delay. Both techniques provide an estimate of the internal processing time, which can be as short as 100 milliseconds for a first-order target. Assessed by the correlogram method, the response to flicker-defined motion is delayed by more than 100 milliseconds, and significantly weaker (especially in the vertical dimension). When initially presented in the delayed feedback condition, purely saccadic oscillation is observed. One subject eventually developed smooth oscillations (albeit with significant saccadic intrusions), showing a period-versus-delay slope similar to that observed for first-order targets. This result is somewhat surprising, given that we interpret the slope of the period-versus-delay-function as reflecting the balance between position- and velocity
Anisotropic Smoothing Improves DT-MRI-Based Muscle Fiber Tractography.
Directory of Open Access Journals (Sweden)
Amanda K W Buck
Full Text Available To assess the effect of anisotropic smoothing on fiber tracking measures, including pennation angle, fiber tract length, and fiber tract number in the medial gastrocnemius (MG muscle in healthy subjects using diffusion-weighted magnetic resonance imaging (DW-MRI.3T DW-MRI data were used for muscle fiber tractography in the MG of healthy subjects. Anisotropic smoothing was applied at three levels (5%, 10%, 15%, and pennation angle, tract length, fiber tract number, fractional anisotropy, and principal eigenvector orientation were quantified for each smoothing level.Fiber tract length increased with pre-fiber tracking smoothing, and local heterogeneities in fiber direction were reduced. However, pennation angle was not affected by smoothing.Modest anisotropic smoothing (10% improved fiber-tracking results, while preserving structural features.
Impact of FM-AM conversion on smoothing by spectral dispersion
Penninckx, Denis; Coïc, Hervé; Leblanc, Adrien; Chatagnier, Aurore; Bourgeade, Antoine; d'Humières, Emmanuel; Loiseau, Pascal
2015-02-01
In order to set the shape of the focal spot, high power lasers for inertial confinement fusion have a phase plate at the end of the chain. This produces hot spots that can be avoided by the use of optical smoothing. Smoothing consists either in reducing the number of high-energy hot spots by splitting the focal spot energy on two orthogonal states of polarization or in moving the speckle pattern sufficiently fast so that the focal spot seems more homogeneous over time. In the latter case, the spectrum is broadened by a temporal phase modulation and dispersed with a grating. However, because of propagation impairments (filtering functions, chromatic dispersion, frequency conversion,...), part of the frequency modulation is converted into detrimental amplitude modulation. This is called FM-AM conversion. Its impact on smoothing performance is considered here. Three main parameters may be affected: power fluctuations of the focal spot, size of the speckle hot spots (autocorrelation function) and dynamic of the evolution of the spatial contrast of the focal spot versus time. We show that depending on the features of the FM-AM conversion (frequency content of AM, type of filtering function) either one or more of these parameters may be affected. As a matter of fact, a low frequency AM induces power fluctuations while higher frequency AM induces variation of the autocorrelation function. Moreover, as opposed to an amplitude-filtering function, chromatic dispersion will not change the power spectral density of the pulse and thus the dynamic of the contrast.
Changes of smooth muscle contractile filaments in small bowel atresia
Gfrörer, Stefan; Fiegel, Henning; Ramachandran, Priya; Rolle, Udo; Metzger, Roman
2012-01-01
AIM: To investigate morphological changes of intestinal smooth muscle contractile fibres in small bowel atresia patients. METHODS: Resected small bowel specimens from small bowel atresia patients (n = 12) were divided into three sections (proximal, atretic and distal). Standard histology hematoxylin-eosin staining and enzyme immunohistochemistry was performed to visualize smooth muscle contractile markers α-smooth muscle actin (SMA) and desmin using conventional paraffin sections of the proxi...
Caveolin-3 promotes a vascular smooth muscle contractile phenotype
Directory of Open Access Journals (Sweden)
Jorge L. Gutierrez-Pajares
2015-06-01
Full Text Available Epidemiological studies have demonstrated the importance of cardiovascular diseases in Western countries. Among the cell types associated with a dysfunctional vasculature, smooth muscle cells are believed to play an essential role in the development of these illnesses. Vascular smooth muscle cells are key regulators of the vascular tone and also have an important function in the development of atherosclerosis and restenosis. While in the normal vasculature contractile smooth muscle cells are predominant, in atherosclerotic vascular lesions, synthetic cells migrate toward the neointima, proliferate, and synthetize extracellular matrix proteins. In the present study, we have examined the role of caveolin-3 in the regulation of smooth muscle cell phenotype. Caveolin-3 is expressed in vivo in normal arterial smooth muscle cells, but its expression appears to be lost in cultured smooth muscle cells. Our data show that caveolin-3 expression in the A7r5 smooth muscle cell line is associated with increased expression of contractility markers such as smooth muscle actin, smooth muscle myosin heavy chain but decreased expression of the synthetic phenotype markers such as p-Elk and Klf4. Moreover, we also show that caveolin-3 expression can reduce proliferation upon treatment with LDL or PDGF. Finally, we show that caveolin-3-expressing smooth muscle cells are less sensitive to apoptosis than control cells upon treatment with oxidized LDL. Taken together, our data suggest that caveolin-3 can regulate the phenotypic switch between contractile and synthetic smooth muscle cells. A better understanding of the factors regulating caveolin-3 expression and function in this cell type will permit the development of a better comprehension of the factors regulating smooth muscle function in atherosclerosis and restenosis.
Modifying the double smoothing bandwidth selector in nonparametric regression
Beran, Jan; Feng, Yuanhua; Heiler, Siegfried
2000-01-01
In this paper a modified double smoothing bandwidth selector, ^h MDS , based on a new criterion, which combines the plug-in and the double smoothing ideas, is proposed. A self-complete iterative double smoothing rule ( ^ h IDS ) is introduced as a pilot method. The asymptotic properties of both ^ h IDS and ^ h MDS are investigated. It is shown that ^ h MDS performs asymptotically very well. Moreover, it is asymptotically negatively correlated with h ASE , the minimizer of the averaged squared...
Recursive Robot-Arm Dynamics via Filtering and Smoothing
Rodriguez, Guillermo
1987-01-01
Forward and inverse dynamics solved using Kalman filtering and Bryson-Frazier smoothing. Dynamics of serial-link robot arm solved by using recursive techniques from linear filtering and smoothing theory. Solutions of dynamical equations give forces, moments, and accelerations at joints between links, and multilink inertia matrix and its inverse. Theoretical developments lay foundation for use of filtering and smoothing techniques in design of robot controls.
Robust forecasting with exponential and Holt-Winters smoothing.
Gelper, SEC Sarah; Fried, R; Croux, C.
2007-01-01
Robust versions of the exponential and Holt-Winters smoothing method for forecasting are presented. They are suitable for forecasting univariate time series in presence of outliers. The robust exponential and Holt-Winters smoothing methods are presented as a recursive updating scheme. Both the update equation and the selection of the smoothing parameters are robustied. This robust method is equivalent to a particular form of the robust Kalman lter in a local linear trend model. A simulation s...
Hydrochlorothiazide Potentiates Contractile Activity of Mouse Cavernosal Smooth Muscle
Directory of Open Access Journals (Sweden)
Thiago Gagliano-Jucá, MD, PhD
2016-06-01
Conclusion: Hydrochlorothiazide potentiates contraction of smooth muscle from mouse CC. These findings could explain why diuretics such as hydrochlorothiazide are associated with erectile dysfunction.
How Do Families Smooth Household Heads` Earnings Volatility?
National Research Council Canada - National Science Library
Ki Seong Park;
2010-01-01
We investigate the extent to which household heads` earnings volatility is translated into household consumption volatility, and, in the process, identify measures of smoothing idiosyncratic earnings variation...
I-spline Smoothing for Calibrating Predictive Models.
Wu, Yuan; Jiang, Xiaoqian; Kim, Jihoon; Ohno-Machado, Lucila
2012-01-01
We proposed the I-spline Smoothing approach for calibrating predictive models by solving a nonlinear monotone regression problem. We took advantage of I-spline properties to obtain globally optimal solutions while keeping the computational cost low. Numerical studies based on three data sets showed the empirical evidences of I-spline Smoothing in improving calibration (i.e.,1.6x, 1.4x, and 1.4x on the three datasets compared to the average of competitors-Binning, Platt Scaling, Isotonic Regression, Monotone Spline Smoothing, Smooth Isotonic Regression) without deterioration of discrimination.
Zhang, Rong; Jack, Gregory S; Rao, Nagesh; Zuk, Patricia; Ignarro, Louis J; Wu, Benjamin; Rodríguez, Larissa V
2012-03-01
Human adipose-derived stem cells hASC have been isolated and were shown to have multilineage differentiation capacity. Although both plasticity and cell fusion have been suggested as mechanisms for cell differentiation in vivo, the effect of the local in vivo environment on the differentiation of adipose-derived stem cells has not been evaluated. We previously reported the in vitro capacity of smooth muscle differentiation of these cells. In this study, we evaluate the effect of an in vivo smooth muscle environment in the differentiation of hASC. We studied this by two experimental designs: (a) in vivo evaluation of smooth muscle differentiation of hASC injected into a smooth muscle environment and (b) in vitro evaluation of smooth muscle differentiation capacity of hASC exposed to bladder smooth muscle cells. Our results indicate a time-dependent differentiation of hASC into mature smooth muscle cells when these cells are injected into the smooth musculature of the urinary bladder. Similar findings were seen when the cells were cocultured in vitro with primary bladder smooth muscle cells. Chromosomal analysis demonstrated that microenvironment cues rather than nuclear fusion are responsible for this differentiation. We conclude that cell plasticity is present in hASCs, and their differentiation is accomplished in the absence of nuclear fusion. Copyright © 2011 AlphaMed Press.
An implicit Smooth Particle Hydrodynamic code
Energy Technology Data Exchange (ETDEWEB)
Knapp, Charles E. [Univ. of New Mexico, Albuquerque, NM (United States)
2000-05-01
An implicit version of the Smooth Particle Hydrodynamic (SPH) code SPHINX has been written and is working. In conjunction with the SPHINX code the new implicit code models fluids and solids under a wide range of conditions. SPH codes are Lagrangian, meshless and use particles to model the fluids and solids. The implicit code makes use of the Krylov iterative techniques for solving large linear-systems and a Newton-Raphson method for non-linear corrections. It uses numerical derivatives to construct the Jacobian matrix. It uses sparse techniques to save on memory storage and to reduce the amount of computation. It is believed that this is the first implicit SPH code to use Newton-Krylov techniques, and is also the first implicit SPH code to model solids. A description of SPH and the techniques used in the implicit code are presented. Then, the results of a number of tests cases are discussed, which include a shock tube problem, a Rayleigh-Taylor problem, a breaking dam problem, and a single jet of gas problem. The results are shown to be in very good agreement with analytic solutions, experimental results, and the explicit SPHINX code. In the case of the single jet of gas case it has been demonstrated that the implicit code can do a problem in much shorter time than the explicit code. The problem was, however, very unphysical, but it does demonstrate the potential of the implicit code. It is a first step toward a useful implicit SPH code.
An Improved Sequential Smoothing Particle Filtering Method
Directory of Open Access Journals (Sweden)
Cao Shijie
2017-01-01
Full Text Available In order to cope with the challenges of non-cooperative targets such as stealth targets to modern radar, especially when traditional threshold detection and tracking methods can hardly detect fast-moving stealth targets, technological innovation has long been required. In this paper we have proposed a new algorithm which can reduce computational cost and improve tracking accuracy. Firstly, the number of particles in the traditional particle filter is reduced and a small number of sampling points are derived from the possible distribution of the target to be tracked, each given a proper weight. Then, the transformed sampling points are sequentially smoothed. And finally, the target positions are estimated. The simulation results show that the proposed algorithm is more accurate than the traditional particle filter algorithm and has lower computational complexity. In the case when SNR is between 0dB to 15dB, a total of 100 Monte Carlo simulations are carried out, obtaining a high detection probability. The detection probability of the improved algorithm is higher than that of the existing particle filter at 7dB. Also, the computational cost is lower than the existing particle filter algorithm.
Drop splash on a smooth, dry surface
Riboux, Guillaume; Gordillo, Jose Manuel; Korobkin, Alexander
2013-11-01
It is our purpose here to determine the conditions under which a drop of a given liquid with a known radius R impacting against a smooth impermeable surface at a velocity V, will either spread axisymmetrically onto the substrate or will create a splash, giving rise to usually undesired star-shaped patterns. In our experimental setup, drops are generated injecting low viscosity liquids falling under the action of gravity from a stainless steel hypodermic needle. The experimental observations using two high speed cameras operating simultaneously and placed perpendicularly to each other reveal that, initially, the drop deforms axisymmetrically, with A (T) the radius of the wetted area. For high enough values of the drop impact velocity, a thin sheet of liquid starts to be ejected from A (T) at a velocity Vjet > V for instants of time such that T >=Tc . If Vjet is above a certain threshold, which depends on the solid wetting properties as well as on the material properties of both the liquid and the atmospheric gas, the rim of the lamella dewets the solid to finally break into drops. Using Wagner's theory we demonstrate that A (T) =√{ 3 RVT } and our results also reveal that Tc We - 1 / 2 =(ρV2 R / σ) - 1 / 2 and Vjet We 1 / 4 .
Dynamics of wetting on smooth and rough surfaces.
Cazabat, A.M.; Cohen Stuart, M.A.
1987-01-01
The rate of spreading of non-volatile liquids on smooth and on rough surfaces was investigated. The radius of the wetted spot was found to agree with recently proposed scaling laws (t 1/10 for capillarity driven andt 1/8 for gravity driven spreading) when the surface was smooth. However, the
Three-phase electric drive with modified electronic smoothing inductor
DEFF Research Database (Denmark)
Singh, Yash Veer; Rasmussen, Peter Omand; Andersen, Torben Ole
2010-01-01
This paper presents a three-phase electric drive with a modified electronic smoothing inductor (MESI) having reduced size of passive components. The classical electronic smoothing inductor (ESI) is able to control a diode bridge output current and also reduce not only mains current harmonics...
Genetic Programming with Smooth Operators for Arithmetic Expressions
DEFF Research Database (Denmark)
Ursem, Rasmus Kjær; Krink, Thiemo
2002-01-01
This paper introduces the smooth operators for arithmetic expressions as an approach to smoothening the search space in Genetic Programming (GP). Smooth operator GP interpolates between arithmetic operators such as * and /, thereby allowing a gradual adaptation to the problem. The suggested...
Altered extracellular magnesium and variations in vascular smooth ...
African Journals Online (AJOL)
Background: There is a paucity of information on the heterogeneity of vascular smooth muscles in their responses to agonists following exposure to varying extracellular magnesium, [Mg2+]0. The present study was designed to examine, comparatively, the influence of variations in [Mg2+]0 on vascular smooth muscles of ...
Estimate of K-functionals and modulus of smoothness constructed ...
Indian Academy of Sciences (India)
Using a generalized spherical mean operator, we define generalized modulus of smoothness in the space L k 2 ( R d ) . Based on the Dunkl operator we define Sobolev-type space and -functionals. The main result of the paper is the proof of the equivalence theorem for a -functional and a modulus of smoothness for the ...
Smooth surfaces from bilinear patches: Discrete affine minimal surfaces
Käferböck, Florian
2013-06-01
Motivated by applications in freeform architecture, we study surfaces which are composed of smoothly joined bilinear patches. These surfaces turn out to be discrete versions of negatively curved affine minimal surfaces and share many properties with their classical smooth counterparts. We present computational design approaches and study special cases which should be interesting for the architectural application. 2013 Elsevier B.V.
Bandwidth selection in smoothing functions | Kibua | East African ...
African Journals Online (AJOL)
... inexpensive and, hence, worth adopting. We argue that the bandwidth parameter is determined by two factors: the kernel function and the length of the smoothing region. We give an illustrative example of its application using real data. Keywords: Kernel, Smoothing functions, Bandwidth > East African Journal of Statistics ...
Smooth maps of a foliated manifold in a symplectic manifold
Indian Academy of Sciences (India)
Let be a smooth manifold with a regular foliation F and a 2-form which induces closed forms on the leaves of F in the leaf topology. A smooth map f : ( M , F ) ⟶ ( N , ) in a symplectic manifold ( N , ) is called a foliated symplectic immersion if restricts to an immersion on each leaf of the foliation and further, the ...
A Monte-Carlo weighted moving average process for smoothing ...
African Journals Online (AJOL)
A Monte-Carlo weighted moving average process for smoothing time series data. N Ekhosuehi, DEA Omorogbe. Abstract. A Monte-Carlo weighted moving average procedure was developed for smoothing time series data. The applicability of the method was demonstrated by using two economic time series data set to ...
Airway structural components drive airway smooth muscle remodeling in asthma
Dekkers, Bart G J; Maarsingh, Harm; Meurs, Herman; Gosens, Reinoud
2009-01-01
Chronic asthma is an inflammatory airways disease characterized by pathological changes in the airway smooth muscle (ASM) bundle that contribute to airway obstruction and hyperresponsiveness. Remodeling of the ASM is associated with an increased smooth muscle mass, involving components of cellular
A generalized relative total variation method for image smoothing
Liu, Qiegen; Xiong, Biao; Yang, Dingcheng; Zhang, Minghui
2016-01-01
Recently, two piecewise smooth models L0smoothing and relative total variation (RTV) have been proposed for feature/structure-preserving filtering. One is very efficient for tackling image with little texture patterns and the other has appearance performance on image with abundant uniform textural
On smoothed analysis of quicksort and Hoare's find
Fouz, Mahmoud; Kufleitner, Manfred; Manthey, Bodo; Zeini Jahromi, Nima; Ngo, H.Q.
2009-01-01
We provide a smoothed analysis of Hoare’s find algorithm and we revisit the smoothed analysis of quicksort. Hoare’s find algorithm – often called quickselect – is an easy-to-implement algorithm for finding the $k$-th smallest element of a sequence. While the worst-case number of comparisons that
Dissimilarity for functional data clustering based on smoothing parameter commutation.
Tzeng, ShengLi; Hennig, Christian; Li, Yu-Fen; Lin, Chien-Ju
2017-01-01
Many studies measure the same type of information longitudinally on the same subject at multiple time points, and clustering of such functional data has many important applications. We propose a novel and easy method to implement dissimilarity measure for functional data clustering based on smoothing splines and smoothing parameter commutation. This method handles data observed at regular or irregular time points in the same way. We measure the dissimilarity between subjects based on varying curve estimates with pairwise commutation of smoothing parameters. The intuition is that smoothing parameters of smoothing splines reflect the inverse of the signal-to-noise ratios and that when applying an identical smoothing parameter the smoothed curves for two similar subjects are expected to be close. Our method takes into account the estimation uncertainty using smoothing parameter commutation and is not strongly affected by outliers. It can also be used for outlier detection. The effectiveness of our proposal is shown by simulations comparing it to other dissimilarity measures and by a real application to methadone dosage maintenance levels.
Nekovee, Maziar; Rudd, Richard
2017-01-01
In this paper an overview is given of the current status of 5G industry standards, spectrum allocation and use cases, followed by initial investigations of new opportunities for spectrum sharing in 5G using cognitive radio techniques, considering both licensed and unlicensed scenarios. A particular attention is given to sharing millimeter-wave frequencies, which are of prominent importance for 5G.
Regeneration and Maintenance of Intestinal Smooth Muscle Phenotypes
Walthers, Christopher M.
Tissue engineering is an emerging field of biomedical engineering that involves growing artificial organs to replace those lost to disease or injury. Within tissue engineering, there is a demand for artificial smooth muscle to repair tissues of the digestive tract, bladder, and vascular systems. Attempts to develop engineered smooth muscle tissues capable of contracting with sufficient strength to be clinically relevant have so far proven unsatisfactory. The goal of this research was to develop and sustain mature, contractile smooth muscle. Survival of implanted SMCs is critical to sustain the benefits of engineered smooth muscle. Survival of implanted smooth muscle cells was studied with layered, electrospun polycaprolactone implants with lasercut holes ranging from 0--25% porosity. It was found that greater angiogenesis was associated with increased survival of implanted cells, with a large increase at a threshold between 20% and 25% porosity. Heparan sulfate coatings improved the speed of blood vessel infiltration after 14 days of implantation. With these considerations, thicker engineered tissues may be possible. An improved smooth muscle tissue culture technique was utilized. Contracting smooth muscle was produced in culture by maintaining the native smooth muscle tissue organization, specifically by sustaining intact smooth muscle strips rather than dissociating tissue in to isolated smooth muscle cells. Isolated cells showed a decrease in maturity and contained fewer enteric neural and glial cells. Muscle strips also exhibited periodic contraction and regular fluctuation of intracellular calclium. The muscle strip maturity persisted after implantation in omentum for 14 days on polycaprolactone scaffolds. A low-cost, disposable bioreactor was developed to further improve maturity of cultured smooth muscle cells in an environment of controlled cyclical stress.The bioreactor consistently applied repeated mechanical strain with controllable inputs for strain
LUM Smoother with Smooth Control for Noisy Image Sequences
Directory of Open Access Journals (Sweden)
Lukàč Rastislav
2001-01-01
Full Text Available This paper focuses on adaptive structure of LUM (lower-upper-middle smoothers for noisy image sequences. For the balance between noise suppression and signal-detail preservation, the LUM smoothers are widely used in smoothing applications. The amount of smoothing done by LUM smoothers is controlled by tuning parameter. However, the smoothing level is fixed for whole image. Thus, the excessive or insufficient smoothing can be performed. This problem is solved by a new method based on the adaptive controlled level of smoothing. A new method has excellent performance of the noise reduction in the environments corrupted by the impulse noise. In addition, minimal signal-detail and motion blurring can be observed. The performance of proposed method is evaluated through objective criteria and compared with traditional temporal, spatial, and spatiotemporal LUM smoothers.
Moving least-squares corrections for smoothed particle hydrodynamics
Directory of Open Access Journals (Sweden)
Ciro Del Negro
2011-12-01
Full Text Available First-order moving least-squares are typically used in conjunction with smoothed particle hydrodynamics in the form of post-processing filters for density fields, to smooth out noise that develops in most applications of smoothed particle hydrodynamics. We show how an approach based on higher-order moving least-squares can be used to correct some of the main limitations in gradient and second-order derivative computation in classic smoothed particle hydrodynamics formulations. With a small increase in computational cost, we manage to achieve smooth density distributions without the need for post-processing and with higher accuracy in the computation of the viscous term of the Navier–Stokes equations, thereby reducing the formation of spurious shockwaves or other streaming effects in the evolution of fluid flow. Numerical tests on a classic two-dimensional dam-break problem confirm the improvement of the new approach.
The effect of robot dynamics on smoothness during wrist pointing.
Erwin, Andrew; Pezent, Evan; Bradley, Joshua; O'Malley, Marcia K
2017-07-01
The improvement of movement smoothness over the course of therapy is one of the positive outcomes observed during robotic rehabilitation. Although movements are generally robust to disturbances, certain perturbations might disrupt an individual's ability to produce these smooth movements. In this paper, we explore how a rehabilitation robot's inherent dynamics impact movement smoothness during pointing tasks. Able-bodied participants made wrist pointing movements under four different operating conditions. Despite the relative transparency of the device, inherent dynamic characteristics negatively impacted movement smoothness. Active compensation for Coulomb friction effects failed to mitigate the degradation in smoothness. Assessment of movements that involved coupled motions of the robot's joints reduced the bias seen in single degree of freedom movements. When using robotic devices for assessment of movement quality, the impact of the inherent dynamics must be considered.
ON THE DERIVATIVE OF SMOOTH MEANINGFUL FUNCTIONS
Directory of Open Access Journals (Sweden)
Sanjo Zlobec
2011-02-01
Full Text Available The derivative of a function f in n variables at a point x* is one of the most important tools in mathematical modelling. If this object exists, it is represented by the row n-tuple f(x* = [∂f/∂xi(x*] called the gradient of f at x*, abbreviated: “the gradient”. The evaluation of f(x* is usually done in two stages, first by calculating the n partials and then their values at x = x*. In this talk we give an alternative approach. We show that one can characterize the gradient without differentiation! The idea is to fix an arbitrary row n-tuple G and answer the following question: What is a necessary and sufficient condition such that G is the gradient of a given f at a given x*? The answer is given after adjusting the quadratic envelope property introduced in [3]. We work with smooth, i.e., continuously differentiable, functions with a Lipschitz derivative on a compact convex set with a non-empty interior. Working with this class of functions is not a serious restriction. In fact, loosely speaking, “almost all” smooth meaningful functions used in modelling of real life situations are expected to have a bounded “acceleration” hence they belong to this class. In particular, the class contains all twice differentiable functions [1]. An important property of the functions from this class is that every f can be represented as the difference of some convex function and a convex quadratic function. This decomposition was used in [3] to characterize the zero derivative points. There we obtained reformulations and augmentations of some well known classic results on optimality such as Fermats extreme value theorem (known from high school and the Lagrange multiplier theorem from calculus [2, 3]. In this talk we extend the results on zero derivative points to characterize the relation G = f(x*, where G is an arbitrary n-tuple. Some special cases: If G = O, we recover the results on zero derivative points. For functions of a single
Adaptively smoothed seismicity earthquake forecasts for Italy
Directory of Open Access Journals (Sweden)
Yan Y. Kagan
2010-11-01
Full Text Available We present a model for estimation of the probabilities of future earthquakes of magnitudes m ≥ 4.95 in Italy. This model is a modified version of that proposed for California, USA, by Helmstetter et al. [2007] and Werner et al. [2010a], and it approximates seismicity using a spatially heterogeneous, temporally homogeneous Poisson point process. The temporal, spatial and magnitude dimensions are entirely decoupled. Magnitudes are independently and identically distributed according to a tapered Gutenberg-Richter magnitude distribution. We have estimated the spatial distribution of future seismicity by smoothing the locations of past earthquakes listed in two Italian catalogs: a short instrumental catalog, and a longer instrumental and historic catalog. The bandwidth of the adaptive spatial kernel is estimated by optimizing the predictive power of the kernel estimate of the spatial earthquake density in retrospective forecasts. When available and reliable, we used small earthquakes of m ≥ 2.95 to reveal active fault structures and 29 probable future epicenters. By calibrating the model with these two catalogs of different durations to create two forecasts, we intend to quantify the loss (or gain of predictability incurred when only a short, but recent, data record is available. Both forecasts were scaled to five and ten years, and have been submitted to the Italian prospective forecasting experiment of the global Collaboratory for the Study of Earthquake Predictability (CSEP. An earlier forecast from the model was submitted by Helmstetter et al. [2007] to the Regional Earthquake Likelihood Model (RELM experiment in California, and with more than half of the five-year experimental period over, the forecast has performed better than the others.
Bronchial Smooth Muscle Remodeling in Nonsevere Asthma.
Girodet, Pierre-Olivier; Allard, Benoit; Thumerel, Matthieu; Begueret, Hugues; Dupin, Isabelle; Ousova, Olga; Lassalle, Régis; Maurat, Elise; Ozier, Annaig; Trian, Thomas; Marthan, Roger; Berger, Patrick
2016-03-15
Increased bronchial smooth muscle (BSM) mass is a key feature of airway remodeling that classically distinguishes severe from nonsevere asthma. Proliferation of BSM cells involves a specific mitochondria-dependent pathway in individuals with severe asthma. However, BSM remodeling and mitochondrial biogenesis have not been examined in nonsevere asthma. We aimed to assess whether an increase in BSM mass was also implicated in nonsevere asthma and its relationship with mitochondria and clinical outcomes. We enrolled 34 never-smoker subjects with nonsevere asthma. In addition, we recruited 56 subjects with nonsevere asthma and 19 subjects with severe asthma as comparative groups (COBRA cohort [Cohorte Obstruction Bronchique et Asthme; Bronchial Obstruction and Asthma Cohort; sponsored by the French National Institute of Health and Medical Research, INSERM]). A phenotypic characterization was performed using questionnaires, atopy and pulmonary function testing, exhaled nitric oxide measurement, and blood collection. Bronchial biopsy specimens were processed for immunohistochemistry and electron microscopy analysis. After BSM remodeling assessment, subjects were monitored over a 12-month period. We identified characteristic features of remodeling (BSM area >26.6%) and increased mitochondrial number within BSM in a subgroup of subjects with nonsevere asthma. The number of BSM mitochondria was positively correlated with BSM area (r = 0.78; P asthma with high BSM had worse asthma control and a higher rate of exacerbations per year compared with subjects with low BSM. This study reveals that BSM remodeling and mitochondrial biogenesis may play a critical role in the natural history of nonsevere asthma (Mitasthme study). Clinical trial registered with www.clinicaltrials.gov (NCT00808730).
An invertebrate smooth muscle with striated muscle myosin filaments
Sulbarán, Guidenn; Alamo, Lorenzo; Pinto, Antonio; Márquez, Gustavo; Méndez, Franklin; Padrón, Raúl; Craig, Roger
2015-01-01
Muscle tissues are classically divided into two major types, depending on the presence or absence of striations. In striated muscles, the actin filaments are anchored at Z-lines and the myosin and actin filaments are in register, whereas in smooth muscles, the actin filaments are attached to dense bodies and the myosin and actin filaments are out of register. The structure of the filaments in smooth muscles is also different from that in striated muscles. Here we have studied the structure of myosin filaments from the smooth muscles of the human parasite Schistosoma mansoni. We find, surprisingly, that they are indistinguishable from those in an arthropod striated muscle. This structural similarity is supported by sequence comparison between the schistosome myosin II heavy chain and known striated muscle myosins. In contrast, the actin filaments of schistosomes are similar to those of smooth muscles, lacking troponin-dependent regulation. We conclude that schistosome muscles are hybrids, containing striated muscle-like myosin filaments and smooth muscle-like actin filaments in a smooth muscle architecture. This surprising finding has broad significance for understanding how muscles are built and how they evolved, and challenges the paradigm that smooth and striated muscles always have distinctly different components. PMID:26443857
Smooth pursuit eye movements and schizophrenia: literature review.
Franco, J G; de Pablo, J; Gaviria, A M; Sepúlveda, E; Vilella, E
2014-09-01
To review the scientific literature about the relationship between impairment on smooth pursuit eye movements and schizophrenia. Narrative review that includes historical articles, reports about basic and clinical investigation, systematic reviews, and meta-analysis on the topic. Up to 80% of schizophrenic patients have impairment of smooth pursuit eye movements. Despite the diversity of test protocols, 65% of patients and controls are correctly classified by their overall performance during this pursuit. The smooth pursuit eye movements depend on the ability to anticipate the target's velocity and the visual feedback, as well as on learning and attention. The neuroanatomy implicated in smooth pursuit overlaps to some extent with certain frontal cortex zones associated with some clinical and neuropsychological characteristics of the schizophrenia, therefore some specific components of smooth pursuit anomalies could serve as biomarkers of the disease. Due to their sedative effect, antipsychotics have a deleterious effect on smooth pursuit eye movements, thus these movements cannot be used to evaluate the efficacy of the currently available treatments. Standardized evaluation of smooth pursuit eye movements on schizophrenia will allow to use specific aspects of that pursuit as biomarkers for the study of its genetics, psychopathology, or neuropsychology. Copyright © 2013 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.
Efficient computation of smoothing splines via adaptive basis sampling
Ma, Ping
2015-06-24
© 2015 Biometrika Trust. Smoothing splines provide flexible nonparametric regression estimators. However, the high computational cost of smoothing splines for large datasets has hindered their wide application. In this article, we develop a new method, named adaptive basis sampling, for efficient computation of smoothing splines in super-large samples. Except for the univariate case where the Reinsch algorithm is applicable, a smoothing spline for a regression problem with sample size n can be expressed as a linear combination of n basis functions and its computational complexity is generally O(n^{3}). We achieve a more scalable computation in the multivariate case by evaluating the smoothing spline using a smaller set of basis functions, obtained by an adaptive sampling scheme that uses values of the response variable. Our asymptotic analysis shows that smoothing splines computed via adaptive basis sampling converge to the true function at the same rate as full basis smoothing splines. Using simulation studies and a large-scale deep earth core-mantle boundary imaging study, we show that the proposed method outperforms a sampling method that does not use the values of response variables.
Super-smooth polishing on aspherical surfaces (II): achievement of a super-smooth polishing
Ando, Manabu; Negishi, Mahito; Takimoto, Masafumi; Deguchi, Akinobu; Nakamura, Nobuo
1995-08-01
This paper discusses super-smooth polishing technology for excimer lasers, soft X-rays, and other short-wavelength light applications. Short-wavelength light elements require surface quality and contour accuracy superior to traditional specifications, as well as free-form contours. For this reason, our target for free-form contours of a 500 mm diameter was set to 0.08 mm PV for contour accuracy, and 0.2 nm RMS for surface roughness. To improve surface quality we employed local pitch polishing, utilizing a flexible tool laminated with an elastic sheet, which adapts well to various contours. For greater contour accuracy, we developed the CSSP (Canon Super-Smooth Polisher), which polishes 500 mm diameter optical elements. The CSSP polishing process achieves a contour accuracy of 0.078 mm PV and a surface roughness of 0.13 nm RMS on a 500 mm diameter fused silica toroidal mirror. We also fabricated both CaF2 and CVD-SiC, materials widely used in short-wavelength light elements.
Direct Data Domain Sparsity-Based STAP Utilizing Subaperture Smoothing Techniques
Directory of Open Access Journals (Sweden)
Zhaocheng Yang
2015-01-01
Full Text Available We propose a novel direct data domain (D3 sparsity-based space-time adaptive processing (STAP algorithm utilizing subaperture smoothing techniques for airborne radar applications. Different from either normal sparsity-based STAP or D3 sparsity-based STAP, the proposed algorithm firstly uses only the snapshot in the cell under test (CUT to generate multiple subsnapshots by exploiting the space-time structure of the steering vector and the uncorrelated nature of the components of the interference covariance matrix. Since the interference spectrum is sparse in the whole angle-Doppler plane, by employing a sparse regularization, the generated multiple subsnapshots are jointly used to recover the interference spectrum. The interference covariance matrix is then estimated from the interference spectrum, followed by the space-time filtering and the target detection. Simulation results illustrate that the proposed algorithm outperforms the generalized forward/backward method, the conventional D3 least squares STAP algorithm, and the existing D3 sparsity-based STAP algorithm. Furthermore, compared with the normal sparsity-based STAP algorithm using multiple snapshots, the proposed algorithm can also avoid the performance degradation caused by discrete interferers merely appearing in the CUT.
Smooth muscle phenotypic modulation--a personal experience.
Campbell, Julie H; Campbell, Gordon R
2012-08-01
The idea that smooth muscle cells can exist in multiple phenotypic states depending on the functional demands placed upon them has been around for >5 decades. However, much of the literature today refers to only recent articles, giving the impression that it is a new idea. At the same time, the current trend is to delve deeper and deeper into transcriptional regulation of smooth muscle genes, and much of the work describing the change in biology of the cells in the different phenotypic states does not appear to be known. This loss of historical perspective regarding the biology of smooth muscle phenotypic modulation is what the current article has tried to mitigate.
Stabilizing S.P.H. with conservative smoothing
Energy Technology Data Exchange (ETDEWEB)
Wen, Y.; Hicks, D.L. [Michigan Tech. Univ., Houghton, MI (United States); Swegle, J.W. [Sandia National Labs., Albuquerque, NM (United States)
1994-08-01
There is an instability in certain S.P.H. (Smoothed Particle Hydrodynamics method) material dynamics computations. Evidence from analyses and experiments suggests that the instabilities in S.P.H. are not removable with artificial viscosities. However, the analysis shows that a type of conservative smoothing does remove the instability. Also, numerical experiments, on certain test problems, show that SPHCS, and S.P.H. code with conservative smoothing, compares well in accuracy with computations based on the von Neumann-Richtmyer method.
EXCHANGE-RATES FORECASTING: EXPONENTIAL SMOOTHING TECHNIQUES AND ARIMA MODELS
Directory of Open Access Journals (Sweden)
Dezsi Eva
2011-07-01
Full Text Available Exchange rates forecasting is, and has been a challenging task in finance. Statistical and econometrical models are widely used in analysis and forecasting of foreign exchange rates. This paper investigates the behavior of daily exchange rates of the Romanian Leu against the Euro, United States Dollar, British Pound, Japanese Yen, Chinese Renminbi and the Russian Ruble. Smoothing techniques are generated and compared with each other. These models include the Simple Exponential Smoothing technique, as the Double Exponential Smoothing technique, the Simple Holt-Winters, the Additive Holt-Winters, namely the Autoregressive Integrated Moving Average model.
DEFF Research Database (Denmark)
Reuman, Daniel C.; Gislason, Henrik; Barnes, Carolyn
2014-01-01
of taxonomy (all the species in a region regardless of clade) are much less studied but are equally important and will illuminate a different set of ecological and evolutionary processes. We develop and test a mechanistic model of how diversity varies with body mass in marine ecosystems. The model predicts...... the form of the diversity spectrum', which quantifies the distribution of species' asymptotic body masses, is a species analogue of the classic size spectrum of individuals, and which we have found to be a new and widely applicable description of diversity patterns. The marine diversity spectrum...... is predicted to be approximately linear across an asymptotic mass range spanning seven orders of magnitude. Slope -0 center dot 5 is predicted for the global marine diversity spectrum for all combined pelagic zones of continental shelf seas, and slopes for large regions are predicted to lie between -0 center...
Fetal Alcohol Spectrum Disorders
Alcohol can harm your baby at any stage during a pregnancy. That includes the earliest stages, before ... can cause a group of conditions called fetal alcohol spectrum disorders (FASDs). Children who are born with ...
Todd, Donald; Tsvetkov, Pavel
2012-01-01
Fast Spectrum Reactors presents a detailed overview of world-wide technology contributing to the development of fast spectrum reactors. With a unique focus on the capabilities of fast spectrum reactors to address nuclear waste transmutation issues, in addition to the well-known capabilities of breeding new fuel, this volume describes how fast spectrum reactors contribute to the wide application of nuclear power systems to serve the global nuclear renaissance while minimizing nuclear proliferation concerns. Readers will find an introduction to the sustainable development of nuclear energy and the role of fast reactors, in addition to an economic analysis of nuclear reactors. A section devoted to neutronics offers the current trends in nuclear design, such as performance parameters and the optimization of advanced power systems. The latest findings on fuel management, partitioning and transmutation include the physics, efficiency and strategies of transmutation, homogeneous and heterogeneous recycling, in addit...
Autism Spectrum Disorder (ASD)
... Español (Spanish) Recommend on Facebook Tweet Share Compartir Autism spectrum disorder (ASD) is a developmental disability that ... interview about being fathers of sons who have autism. Watch more Autism videos COMMUNITY REPORT The Community ...
Neutron spectrum unfolding using computer code SAIPS
Karim, S
1999-01-01
The main objective of this project was to study the neutron energy spectrum at rabbit station-1 in Pakistan Research Reactor (PARR-I). To do so, multiple foils activation method was used to get the saturated activities. The computer code SAIPS was used to unfold the neutron spectra from the measured reaction rates. Of the three built in codes in SAIPS, only SANDI and WINDOWS were used. Contribution of thermal part of the spectra was observed to be higher than the fast one. It was found that the WINDOWS gave smooth spectra while SANDII spectra have violet oscillations in the resonance region. The uncertainties in the WINDOWS results are higher than those of SANDII. The results show reasonable agreement with the published results.
Spectrum and network measurements
Witte, Robert A
2014-01-01
This new edition of Spectrum and Network Measurements enables readers to understand the basic theory, relate it to measured results, and apply it when creating new designs. This comprehensive treatment of frequency domain measurements successfully consolidates all the pertinent theory into one text. It covers the theory and practice of spectrum and network measurements in electronic systems. It also provides thorough coverage of Fourier analysis, transmission lines, intermodulation distortion, signal-to-noise ratio and S-parameters.
Autism spectrum disorder - Asperger syndrome
... part of the larger developmental disorder category of autism spectrum disorder . ... American Psychiatric Association. Autism spectrum disorder. ... VA: American Psychiatric Publishing: 2013;50-59. Raviola GJ, ...
A wave smoothing algorithm and applications to the financial markets
National Research Council Canada - National Science Library
Omar Ait Hellal; Gerald H Meyer
2014-01-01
In this paper we present an algorithm that can be implemented recursively or iteratively, to smooth waves by filtering out "noise" until the base case is reached, a canonical form that we call the wave's imprint...
Calcium-sensitivity of smooth muscle contraction in the isolated ...
African Journals Online (AJOL)
sensitivity of smooth muscle contraction were studied in the isolated perfused rat tail artery, employing the activators noradrenaline (NA) (3ìM) sand potassium chloride (KC1) (100mM). Experiments were conduced in Ca2+ - buffered saline.
Modeling Free-surface Solitary Waves with Smoothed Particle Hydrodynamics
National Research Council Canada - National Science Library
Balázs Tóth
2017-01-01
A three-dimensional weakly compressible Smoothed Particle Hydrodynamics (SPH) solver is presented and applied to simulate free-surface solitary waves generated in a quasi two dimensional dam-break experiment...
Iterative Bias Reduction Multivariate Smoothing in R: The ibr Package
Directory of Open Access Journals (Sweden)
Pierre-André Cornillon
2017-05-01
Full Text Available In multivariate nonparametric analysis curse of dimensionality forces one to use large smoothing parameters. This leads to a biased smoother. Instead of focusing on optimally selecting the smoothing parameter, we fix it to some reasonably large value to ensure an over-smoothing of the data. The resulting base smoother has a small variance but a substantial bias. In this paper, we propose an R package named ibr to iteratively correct the initial bias of the (base estimator by an estimate of the bias obtained by smoothing the residuals. After a brief description of iterated bias reduction smoothers, we examine the base smoothers implemented in the package: Nadaraya-Watson kernel smoothers, Duchon splines smoothers and their low rank counterparts. Then, we explain the stopping rules available in the package and their implementation. Finally we illustrate the package on two examples: a toy example in R2 and the original Los Angeles ozone dataset.
Functional consequences of human airway smooth muscle phenotype plasticity
Dekkers, Bart G J; Bos, I Sophie T; Zaagsma, Johan; Meurs, Herman
BACKGROUND AND PURPOSE: Airway smooth muscle (ASM) phenotype plasticity, characterized by reversible switching between contractile and proliferative phenotypes, is considered to contribute to increased ASM mass and airway hyper-responsiveness in asthma. Further, increased expression of collagen I
Derivatives of Multivariate Bernstein Operators and Smoothness with Jacobi Weights
Directory of Open Access Journals (Sweden)
Jianjun Wang
2012-01-01
Full Text Available Using the modulus of smoothness, directional derivatives of multivariate Bernstein operators with weights are characterized. The obtained results partly generalize the corresponding ones for multivariate Bernstein operators without weights.
A robust Kalman framework with resampling and optimal smoothing
National Research Council Canada - National Science Library
Kautz, Thomas; Eskofier, Bjoern M
2015-01-01
.... We introduce a novel Kalman-based analysis procedure that encompasses robustness towards outliers, Kalman smoothing and real-time conversion from non-uniformly sampled inputs to a constant output rate...
Estimation of UAV Position with Use of Smoothing Algorithms
Directory of Open Access Journals (Sweden)
Kaniewski Piotr
2017-03-01
Full Text Available The paper presents methods of on-line and off-line estimation of UAV position on the basis of measurements from its integrated navigation system. The navigation system installed on board UAV contains an INS and a GNSS receiver. The UAV position, as well as its velocity and orientation are estimated with the use of smoothing algorithms. For off-line estimation, a fixed-interval smoothing algorithm has been applied. On-line estimation has been accomplished with the use of a fixed-lag smoothing algorithm. The paper includes chosen results of simulations demonstrating improvements of accuracy of UAV position estimation with the use of smoothing algorithms in comparison with the use of a Kalman filter.
Interference between smooth pursuit and color working memory
Yue, Shulin; Jin, Zhenlan; Fan, Chenggui; Zhang, Qian; Li, Ling
2017-01-01
Spatial working memory (WM) and spatial attention are closely related, but the relationship between non-spatial WM and spatial attention still remains unclear. The present study aimed to investigate the interaction between color WM and smooth pursuit eye movements. A modified delayed-match-to-sample paradigm (DMS) was applied with 2 or 4 items presented in each visual field. Subjects memorized the colors of items in the cued visual field and smoothly moved eyes towards or away from memorized ...
Ureter smooth muscle cell orientation in rat is predominantly longitudinal.
Spronck, Bart; Merken, Jort J; Reesink, Koen D; Kroon, Wilco; Delhaas, Tammo
2014-01-01
In ureter peristalsis, the orientation of the contracting smooth muscle cells is essential, yet current descriptions of orientation and composition of the smooth muscle layer in human as well as in rat ureter are inconsistent. The present study aims to improve quantification of smooth muscle orientation in rat ureters as a basis for mechanistic understanding of peristalsis. A crucial step in our approach is to use two-photon laser scanning microscopy and image analysis providing objective, quantitative data on smooth muscle cell orientation in intact ureters, avoiding the usual sectioning artifacts. In 36 rat ureter segments, originating from a proximal, middle or distal site and from a left or right ureter, we found close to the adventitia a well-defined longitudinal smooth muscle orientation. Towards the lamina propria, the orientation gradually became slightly more disperse, yet the main orientation remained longitudinal. We conclude that smooth muscle cell orientation in rat ureter is predominantly longitudinal, though the orientation gradually becomes more disperse towards the proprial side. These findings do not support identification of separate layers. The observed longitudinal orientation suggests that smooth muscle contraction would rather cause local shortening of the ureter, than cause luminal constriction. However, the net-like connective tissue of the ureter wall may translate local longitudinal shortening into co-local luminal constriction, facilitating peristalsis. Our quantitative, minimally invasive approach is a crucial step towards more mechanistic insight into ureter peristalsis, and may also be used to study smooth muscle cell orientation in other tube-like structures like gut and blood vessels.
Smooth maps of a foliated manifold in a symplectic manifold
Indian Academy of Sciences (India)
Abstract. Let M be a smooth manifold with a regular foliation F and a 2-form ω which induces closed forms on the leaves of F in the leaf topology. A smooth map f : (M, F) −→ (N,σ) in a symplectic manifold (N,σ) is called a foliated symplectic immersion if f restricts to an immersion on each leaf of the foliation and further, the.
Global smoothness preservation and the variation-diminishing property
Directory of Open Access Journals (Sweden)
Gavrea Ioan
1999-01-01
Full Text Available In the center of our paper are two counterexamples showing the independence of the concepts of global smoothness preservation and variation diminution for sequences of approximation operators. Under certain additional assumptions it is shown that the variation-diminishing property is the stronger one. It is also demonstrated, however, that there are positive linear operators giving an optimal pointwise degree of approximation, and which preserve global smoothness, monotonicity and convexity, but are not variation-diminishing.
The evolutionary origin of bilaterian smooth and striated myocytes
Brunet, Thibaut; Fischer, Antje HL; Steinmetz, Patrick RH; Lauri, Antonella; Bertucci, Paola; Arendt, Detlev
2016-01-01
The dichotomy between smooth and striated myocytes is fundamental for bilaterian musculature, but its evolutionary origin is unsolved. In particular, interrelationships of visceral smooth muscles remain unclear. Absent in fly and nematode, they have not yet been characterized molecularly outside vertebrates. Here, we characterize expression profile, ultrastructure, contractility and innervation of the musculature in the marine annelid Platynereis dumerilii and identify smooth muscles around the midgut, hindgut and heart that resemble their vertebrate counterparts in molecular fingerprint, contraction speed and nervous control. Our data suggest that both visceral smooth and somatic striated myocytes were present in the protostome-deuterostome ancestor and that smooth myocytes later co-opted the striated contractile module repeatedly – for example, in vertebrate heart evolution. During these smooth-to-striated myocyte conversions, the core regulatory complex of transcription factors conveying myocyte identity remained unchanged, reflecting a general principle in cell type evolution. DOI: http://dx.doi.org/10.7554/eLife.19607.001 PMID:27906129
Understanding Symmetric Smoothing Filters: A Gaussian Mixture Model Perspective
Chan, Stanley H.; Zickler, Todd; Lu, Yue M.
2017-11-01
Many patch-based image denoising algorithms can be formulated as applying a smoothing filter to the noisy image. Expressed as matrices, the smoothing filters must be row normalized so that each row sums to unity. Surprisingly, if we apply a column normalization before the row normalization, the performance of the smoothing filter can often be significantly improved. Prior works showed that such performance gain is related to the Sinkhorn-Knopp balancing algorithm, an iterative procedure that symmetrizes a row-stochastic matrix to a doubly-stochastic matrix. However, a complete understanding of the performance gain phenomenon is still lacking. In this paper, we study the performance gain phenomenon from a statistical learning perspective. We show that Sinkhorn-Knopp is equivalent to an Expectation-Maximization (EM) algorithm of learning a Gaussian mixture model of the image patches. By establishing the correspondence between the steps of Sinkhorn-Knopp and the EM algorithm, we provide a geometrical interpretation of the symmetrization process. This observation allows us to develop a new denoising algorithm called Gaussian mixture model symmetric smoothing filter (GSF). GSF is an extension of the Sinkhorn-Knopp and is a generalization of the original smoothing filters. Despite its simple formulation, GSF outperforms many existing smoothing filters and has a similar performance compared to several state-of-the-art denoising algorithms.
Stimulation of aortic smooth muscle cell mitogenesis by serotonin
Energy Technology Data Exchange (ETDEWEB)
Nemecek, G.M.; Coughlin, S.R.; Handley, D.A.; Moskowitz, M.A.
1986-02-01
Bovine aortic smooth muscle cells in vitro responded to 1 nM to 10 ..mu..M serotonin with increased incorporation of (/sup 3/H)thymidine into DNA. The mitogenic effect of serotonin was half-maximal at 80 nM and maximal above 1 ..mu..M. At a concentration of 1 ..mu..M, serotonin stimulated smooth muscle cell mitogenesis to the same extent as human platelet-derived growth factor (PDGF) at 12 ng/ml. Tryptamine was approx. = 1/10th as potent as serotonin as a mitogen for smooth muscle cells. Other indoles that are structurally related to serotonin (D- and L-tryptophan, 5-hydroxy-L-tryptophan, N-acetyl-5-hydroxytryptamine, melatonin, 5-hydroxyindoleacetic acid, and 5-hydroxytryptophol) and quipazine were inactive. The stimulatory effect of serotonin on smooth muscle cell DNA synthesis required prolonged (20-24 hr) exposure to the agonist and was attenuated in the presence of serotonin D receptor antagonists. When smooth muscle cells were incubated with submaximal concentrations of serotonin and PDGF, synergistic rather than additive mitogenic responses were observed. These data indicate that serotonin has a significant mitogenic effect on smooth muscle cells in vitro, which appears to be mediated by specific plasma membrane receptors.
Understanding Symmetric Smoothing Filters: A Gaussian Mixture Model Perspective.
Chan, Stanley H; Zickler, Todd; Lu, Yue M
2017-11-01
Many patch-based image denoising algorithms can be formulated as applying a smoothing filter to the noisy image. Expressed as matrices, the smoothing filters must be row normalized, so that each row sums to unity. Surprisingly, if we apply a column normalization before the row normalization, the performance of the smoothing filter can often be significantly improved. Prior works showed that such performance gain is related to the Sinkhorn-Knopp balancing algorithm, an iterative procedure that symmetrizes a row-stochastic matrix to a doubly stochastic matrix. However, a complete understanding of the performance gain phenomenon is still lacking. In this paper, we study the performance gain phenomenon from a statistical learning perspective. We show that Sinkhorn-Knopp is equivalent to an expectation-maximization (EM) algorithm of learning a Gaussian mixture model of the image patches. By establishing the correspondence between the steps of Sinkhorn-Knopp and the EM algorithm, we provide a geometrical interpretation of the symmetrization process. This observation allows us to develop a new denoising algorithm called Gaussian mixture model symmetric smoothing filter (GSF). GSF is an extension of the Sinkhorn-Knopp and is a generalization of the original smoothing filters. Despite its simple formulation, GSF outperforms many existing smoothing filters and has a similar performance compared with several state-of-the-art denoising algorithms.
Efficient searching of globally optimal and smooth multi-surfaces with shape priors
Xu, Lei; Stojkovic, Branislav; Ding, Hu; Song, Qi; Wu, Xiaodong; Sonka, Milan; Xu, Jinhui
2012-02-01
Despite extensive studies in the past, the problem of segmenting globally optimal multiple surfaces in 3D volumetric images remains challenging in medical imaging. The problem becomes even harder in highly noisy and edge-weak images. In this paper we present a novel and highly efficient graph-theoretical iterative method based on a volumetric graph representation of the 3D image that incorporates curvature and shape prior information. Compared with the graph-based method, applying the shape prior to construct the graph on a specific preferred shape model allows easy incorporation of a wide spectrum of shape prior information. Furthermore, the key insight that computation of the objective function can be done independently in the x and y directions makes local improvement possible. Thus, instead of using global optimization technique such as maximum flow algorithm, the iteration based method is much faster. Additionally, the utilization of the curvature in the objective function ensures the smoothness. To the best of our knowledge, this is the first paper to combine the shape-prior penalties with utilizing curvature in objective function to ensure the smoothness of the generated surfaces while striving for achieving global optimality. To evaluate the performance of our method, we test it on a set of 14 3D OCT images. Comparing to the best existing approaches, our experiments suggest that the proposed method reduces the unsigned surface positioning errors form 5.44 +/- 1.07(μm) to 4.52 +/- 0.84(μm). Moreover, our method has a much improved running time, yields almost the same global optimality but with much better smoothness, which makes it especially suitable for segmenting highly noisy images. The proposed method is also suitable for parallel implementation on GPUs, which could potentially allow us to segment highly noisy volumetric images in real time.
A New Transceiver for OFDM Systems Using Smooth Local Trigonometric Transforms
Chang, Qing; Tan, Yongbo; Qi, Wei; Chen, Dirong
This letter proposes a new transceiver for OFDM systems based on Smooth Local Trigonometric Transform (LTT). In our transceiver, the transmitter is realized by firstmodulating the original serial data using a constellation mapper, then feeding the results into the inverse LTT modulator. Unlike the conventional DFT-OFDM system, which always uses the roll cosine function as its window function, the proposed system needs no additional window function for the reason that LTT transform includes a bell-shaped window function by itself. Moreover, each LTT-OFDM symbol has a much more rapid attenuation rate outside of the spectral bandwidth and better spectrum convergence. In the receiver, the original data is recovered by demodulating the received data using forward LTT. Comparative simulation results from the conventional DFT-OFDM system, the system we proposed, and the recently proposed DCT based OFDM system are discussed in terms of bit error rate (BER).
Stability of bumps in piecewise smooth neural fields with nonlinear adaptation
Kilpatrick, Zachary P.
2010-06-01
We study the linear stability of stationary bumps in piecewise smooth neural fields with local negative feedback in the form of synaptic depression or spike frequency adaptation. The continuum dynamics is described in terms of a nonlocal integrodifferential equation, in which the integral kernel represents the spatial distribution of synaptic weights between populations of neurons whose mean firing rate is taken to be a Heaviside function of local activity. Discontinuities in the adaptation variable associated with a bump solution means that bump stability cannot be analyzed by constructing the Evans function for a network with a sigmoidal gain function and then taking the high-gain limit. In the case of synaptic depression, we show that linear stability can be formulated in terms of solutions to a system of pseudo-linear equations. We thus establish that sufficiently strong synaptic depression can destabilize a bump that is stable in the absence of depression. These instabilities are dominated by shift perturbations that evolve into traveling pulses. In the case of spike frequency adaptation, we show that for a wide class of perturbations the activity and adaptation variables decouple in the linear regime, thus allowing us to explicitly determine stability in terms of the spectrum of a smooth linear operator. We find that bumps are always unstable with respect to this class of perturbations, and destabilization of a bump can result in either a traveling pulse or a spatially localized breather. © 2010 Elsevier B.V. All rights reserved.
Stein, David B.; Guy, Robert D; Thomases, Becca
2015-01-01
The Immersed Boundary method is a simple, efficient, and robust numerical scheme for solving PDE in general domains, yet it only achieves first-order spatial accuracy near embedded boundaries. In this paper, we introduce a new high-order numerical method which we call the Immersed Boundary Smooth Extension (IBSE) method. The IBSE method achieves high-order accuracy by smoothly extending the unknown solution of the PDE from a given sm...
DEFF Research Database (Denmark)
Frandsen, Lars Hagedorn; Borel, Peter Ingo; Thorhauge, Morten
2003-01-01
In this paper, bends in planar PCWs are investigated by introducing two smoothed 60° bends each having one hole. The PCWs are defined by leaving out single rows of holes. In and out coupling of light to the PCWs is obtained utilising tapered ridge waveguides. Transmission spectra are recorded for...... for both the TE and TM polarisation with an optical spectrum analyser by using two LED sources centred at 1330 nm and 1550 nm. The 3D FDTD simulations successfully explain the observed bend losses both for the TE and TM polarisations....
Bottomonium spectrum revisited
Segovia, Jorge; Entem, David R.; Fernández, Francisco
2016-01-01
We revisit the bottomonium spectrum motivated by the recently exciting experimental progress in the observation of new bottomonium states, both conventional and unconventional. Our framework is a nonrelativistic constituent quark model which has been applied to a wide range of hadronic observables from the light to the heavy quark sector and thus the model parameters are completely constrained. Beyond the spectrum, we provide a large number of electromagnetic, strong and hadronic decays in order to discuss the quark content of the bottomonium states and give more insights about the better way to determine their properties experimentally.
Fermi Bubble Edges: Spectrum and Diffusion Function
Keshet, Uri; Gurwich, Ilya
2017-05-01
Current measurements of the γ-ray Fermi bubbles (FB) are based on model-dependent tracers, carry substantial systematic uncertainties, and contain some discrepancies between each other. We show that gradient filters pick out the FB edges, which are found to smoothly connect to the bipolar X-ray structure emanating from the Galactic center, thus supporting the interpretation of the FBs as a Galactic-scale phenomenon. The sharp edges facilitate a direct, model-free measurement of the peripheral FB spectrum. The result is strikingly similar to the full FB-integrated spectrum, softened by a power law of index η ≃ (0.2-0.3). This is naturally explained, in both hadronic and leptonic models, if cosmic rays are injected at the edge, and diffuse away preferentially at higher energies E. The inferred, averaged diffusion function in the (more plausible) leptonic model, D{(E)≃ {10}29.5(E/10{GeV})}0.48+/- 0.02 {{cm}}2 {{{s}}}-1, is consistent with estimates for Kraichnan-like turbulence. Our results, in particular the minute spatial variations in η, indicate that the FB edge is a strong, Mach ≳5, forward shock.
Intermittent Smoothing Approaches for Wind Power Output: A Review
Directory of Open Access Journals (Sweden)
Muhammad Jabir
2017-10-01
Full Text Available Wind energy is one of the most common types of renewable energy resource. Due to its sustainability and environmental benefits, it is an emerging source for electric power generation. Rapid and random changes of wind speed makes it an irregular and inconsistent power source when connected to the grid, causing different technical problems in protection, power quality and generation dispatch control. Due to these problems, effective intermittent smoothing approaches for wind power output are crucially needed to minimize such problems. This paper reviews various intermittent smoothing approaches used in smoothing the output power fluctuations caused by wind energy. Problems associated with the inclusion of wind energy resources to grid are also briefly reviewed. From this review, it has been found that battery energy storage system is the most suitable and effective smoothing approach, provided that an effective control strategy is available for optimal utilization of battery energy system. This paper further demonstrates different control strategies built for battery energy storage system to obtain the smooth output wind power.
Accuracy of eye position for saccades and smooth pursuit.
Shanidze, Natela; Ghahghaei, Saeideh; Verghese, Preeti
2016-12-01
In this study, we address the question of whether a target is foveated during smooth pursuit. Specifically, we examine whether smooth pursuit eye movements land near the center-of-mass of the target, as is the case for saccades. To that end, we instructed eight untrained, healthy participants to follow moving targets, presented monocularly in a scanning laser ophthalmoscope. Stimuli moved either in a modified step-ramp (smooth pursuit), or made a single step (saccade), stepping 6° from the center. Targets were ring-shaped and either 0.6° or 1.7° in diameter. In an additional set of experiments, two participants collected more extensive data on smooth pursuit and saccades for a larger range of target sizes (0.6°, 1.7°, or 4.3°). During pursuit, eyes were rarely placed at target center, even when participants' fixational stability was taken into account. Furthermore, there was a clear tendency for distance from target center to increase with target size. This outcome was in contrast to saccades, where there was no effect of target size across participants. The difference in foveal placement between the two types of eye movements is consistent with their different purposes: closer inspection of the target for saccades versus maintenance of the target in the visual field for smooth pursuit.
Centers for Disease Control (CDC) Podcasts
2014-04-02
This podcast discusses autism spectrum disorder (ASD), a developmental disability that causes problems with social, communication, and behavioral skills. CDC estimates that one in 68 children has been identified as having ASD. Created: 4/2/2014 by National Center on Birth Defects and Developmental Disabilities (NCBDDD). Date Released: 4/2/2014.
Evans, Neal D.; Capone, Dean E.; Bonness, William K.
2013-07-01
The vibration response of a thin cylindrical shell excited by fully developed turbulent pipe flow is measured and used to extract the fluctuating pressure levels generated by the boundary layer. Parameters used to extract the turbulent fluctuating pressure levels are determined via experimental modal analyses of the water-filled pipe and measured vibration levels from flow through the pipe at 5.8 m/s. Measurements are reported for hydraulically smooth and fully rough surface conditions. Smooth wall-pressure levels are compared to the turbulent boundary layer pressure model of Chase [The character of the turbulent wall pressure at subconvective wavenumbers and a suggested comprehensive model. Journal of Sound and Vibration112 (1) (1987) 125-147] and the measurements of Bonness et al. [Low-wavenumber turbulent boundary layer wall-pressure measurements from vibration data on a cylinder in pipe flow. Journal of Sound and Vibration329 (2010) 4166-4180]. Results for the smooth pipe match the predicted smooth wall-pressure spectrum and correspond to a normalized low wavenumber-white level which is -41 dB below the maximum level at the convective peak. Pressure levels from the fully rough condition display a low-wavenumber-white level which is 28 dB below the convective peak level. This suggests an increase of 13 dB in low-wavenumber wall pressure for the uniformly distributed roughness elements in this study over a hydraulically smooth surface.
Spectrum of localized states in graphene quantum dots and wires
Energy Technology Data Exchange (ETDEWEB)
Zalipaev, V.V. [Department of Mathematical Sciences, Loughborough University, Leicestershire, LE11 3TU (United Kingdom); Maksimov, D.N. [LV Kirensky Institute of Physics, Krasnoyarsk 660036 (Russian Federation); Linton, C.M. [Department of Mathematical Sciences, Loughborough University, Leicestershire, LE11 3TU (United Kingdom); Kusmartsev, F.V., E-mail: F.Kusmartsev@lboro.ac.uk [Department of Physics, Loughborough University, Leicestershire, LE11 3TU (United Kingdom)
2013-01-03
We developed semiclassical method and show that any smooth potential in graphene describing elongated a quantum dot or wire may behave as a barrier or as a trapping well or as a double barrier potential, Fabry–Perot structure, for 1D Schrödinger equation. The energy spectrum of quantum wires has been found and compared with numerical simulations. We found that there are two types of localized states, stable and metastable, having finite life time. These life times are calculated, as is the form of the localized wave functions which are exponentially decaying away from the wire in the perpendicular direction.
Smoothing-Norm Preconditioning for Regularizing Minimum-Residual Methods
DEFF Research Database (Denmark)
Hansen, Per Christian; Jensen, Toke Koldborg
2006-01-01
When GMRES (or a similar minimum-residual algorithm such as RRGMRES, MINRES, or MR-II) is applied to a discrete ill-posed problem with a square matrix, in some cases the iterates can be considered as regularized solutions. We show how to precondition these methods in such a way that the iterations...... take into account a smoothing norm for the solution. This technique is well established for CGLS, but it does not immediately carry over to minimum-residual methods when the smoothing norm is a seminorm or a Sobolev norm. We develop a new technique which works for any smoothing norm of the form $\\|L......\\,x\\|_2$ and which preserves symmetry if the coefficient matrix is symmetric. We also discuss the efficient implementation of our preconditioning technique, and we demonstrate its performance with numerical examples in one and two dimensions....
Return Smoothing Mechanisms in Life and Pension Insurance
DEFF Research Database (Denmark)
Montserrat, Guillén; Jørgensen, Peter Løchte; Nielsen, Jens Perch
2006-01-01
Traditional with-profits pension saving schemes have been criticized for their opacity, plagued by embedded options and guarantees, and have recently created enormous problems for the solvency of the life insurance and pension industry. This has fueled creativity in the industry's product...... development departments, and this paper analyzes a representative member of a family of new pension schemes that have been introduced in the new millennium to alleviate these problems. The complete transparency of the new scheme's smoothing mechanism means that it can be analyzed using contingent claims...... pricing theory. We explore the properties of this pension scheme in detail and find that in terms of market value, smoothing is an illusion, but also that the return smoothing mechanism implies a dynamic asset allocation strategy which corresponds with traditional pension saving advice...
Smoothing the payoff for efficient computation of Basket option prices
Bayer, Christian
2017-07-22
We consider the problem of pricing basket options in a multivariate Black–Scholes or Variance-Gamma model. From a numerical point of view, pricing such options corresponds to moderate and high-dimensional numerical integration problems with non-smooth integrands. Due to this lack of regularity, higher order numerical integration techniques may not be directly available, requiring the use of methods like Monte Carlo specifically designed to work for non-regular problems. We propose to use the inherent smoothing property of the density of the underlying in the above models to mollify the payoff function by means of an exact conditional expectation. The resulting conditional expectation is unbiased and yields a smooth integrand, which is amenable to the efficient use of adaptive sparse-grid cubature. Numerical examples indicate that the high-order method may perform orders of magnitude faster than Monte Carlo or Quasi Monte Carlo methods in dimensions up to 35.
Czuryło, Edward A; Kulikova, Natalia; Sobota, Andrzej
2008-05-01
Lysenin, a toxin present in the coelomic fluid of the earthworm Eisenia foetida, is known to cause a long-lasting contraction of rat aorta smooth muscle strips. We addressed the mechanisms underlying its action on smooth muscle cells and present the first report demonstrating a completely new property of lysenin unrelated to its basic sphingomyelin-binding ability. Here we report lysenin enhancement effect on smooth muscle actomyosin ATPase activity and the ability of networking the actin filaments. The maximum enhancement of the ATPase activity of actomyosin at 120 mM KCl was observed at a molar ratio of lysenin to actin of about 1:10(5), while at 70 mM KCl at the ratio of about 1:10(6). The effect of lysenin became most pronounced only when both smooth muscle regulatory proteins, tropomyosin and caldesmon, were present. Co-sedimentation experiments indicated that lysenin did not displace neither tropomyosin nor caldesmon from the thin filament. Thus, the lysenin-dependent abolishment of the inhibitory effect of caldesmon on the ATPase activity was related rather to the modification of the filament structure. The ability of the toxin to exert its stimulatory effect at extremely low concentrations (as low as one molecule of lysenin per 10(6) actin molecules) may result from the long-range cooperative transitions in the entire thin filament with an involvement of smooth muscle tropomyosin, while the role of caldesmon may be limited exclusively to the inhibition of ATPase activity.
Chlamydia pneumoniae induces aponecrosis in human aortic smooth muscle cells
Directory of Open Access Journals (Sweden)
Walch Michael
2005-01-01
Full Text Available Abstract Background The intracellular bacterium Chlamydia pneumoniae is suspected to play a role in formation and progression of atherosclerosis. Many studies investigated cell death initiation versus inhibition by Chlamydia pneumoniae in established cell lines but nothing is known in primary human aortic smooth muscle cells, a cell type among others known to be involved in the formation of the atherosclerotic plaque. Type of cell death was analyzed by various methods in primary aortic smooth muscle cells after infection with Chlamydia pneumoniae to investigate a possible pathogenic link in atherosclerosis. Results Chlamydiae were found to be localized up to 72 h post infection in aortic smooth muscle cells either as single bacteria or inside of large inclusions. Quantification of host cell death by lactate dehydrogenase release assay revealed strictly dose and time dependent lysis for all tested isolates of Chlamydia pneumoniae. Phosphatidylserine exposure was detected by flow cytometry in Chlamydia pneumoniae infected cells. Ultrastructure of Chlamydia pneumoniae infected human aortic smooth muscle cells showed extensive membrane- and organelle damage, chromatin condensation but no nuclear fragmentation. DNA fragmentation as well as cell membrane permeability was analyzed by TUNEL and NHS-biotin staining and occurred exclusively in cells carrying Chlamydia pneumoniae spots but not in smooth muscle cells with inclusions. These morphological features of cell death were not accompanied by an activation of caspase-3 as revealed by analysis of enzyme activity but involved mitochondrial membrane depolarization as shown by TMRE uptake and release of cytochrome c from mitochondria. Conclusion This study provides evidence that Chlamydia pneumoniae induce a spot like infection in human aortic smooth muscle cells, which results in a chimeric cell death with both apoptotic and necrotic characteristics. This aponecrotic cell death may assist chronic
The Initiation of Smooth Pursuit is Delayed in Anisometropic Amblyopia.
Raashid, Rana Arham; Liu, Ivy Ziqian; Blakeman, Alan; Goltz, Herbert C; Wong, Agnes M F
2016-04-01
Several behavioral studies have shown that the reaction times of visually guided movements are slower in people with amblyopia, particularly during amblyopic eye viewing. Here, we tested the hypothesis that the initiation of smooth pursuit eye movements, which are responsible for accurately keeping moving objects on the fovea, is delayed in people with anisometropic amblyopia. Eleven participants with anisometropic amblyopia and 14 visually normal observers were asked to track a step-ramp target moving at ±15°/s horizontally as quickly and as accurately as possible. The experiment was conducted under three viewing conditions: amblyopic/nondominant eye, binocular, and fellow/dominant eye viewing. Outcome measures were smooth pursuit latency, open-loop gain, steady state gain, and catch-up saccade frequency. Participants with anisometropic amblyopia initiated smooth pursuit significantly slower during amblyopic eye viewing (206 ± 20 ms) than visually normal observers viewing with their nondominant eye (183 ± 17 ms, P = 0.002). However, mean pursuit latency in the anisometropic amblyopia group during binocular and monocular fellow eye viewing was comparable to the visually normal group. Mean open-loop gain, steady state gain, and catch-up saccade frequency were similar between the two groups, but participants with anisometropic amblyopia exhibited more variable steady state gain (P = 0.045). This study provides evidence of temporally delayed smooth pursuit initiation in anisometropic amblyopia. After initiation, the smooth pursuit velocity profile in anisometropic amblyopia participants is similar to visually normal controls. This finding differs from what has been observed previously in participants with strabismic amblyopia who exhibit reduced smooth pursuit velocity gains with more catch-up saccades.
Histomorphometry of penile smooth muscle fiber in severe erectile dysfunction
Directory of Open Access Journals (Sweden)
Joaquim de Almeida Claro
Full Text Available CONTEXT AND OBJECTIVE: Smooth muscle fiber has fundamental importance in erection. Alterations in its function or quantity may be associated with erectile dysfunction. The study objective was to assess the proportion of penile smooth muscle fiber in patients with severe erectile dysfunction. DESIGN AND SETTING: Clinical study, in the Sexual Dysfunction Group, Universidade Federal de São Paulo (Unifesp, and in the Anatomy Laboratory, Universidade Estadual do Rio de Janeiro (UERJ. METHODS: Twenty patients with severe erectile dysfunction were selected to form two groups of ten patients: one with normal arterial flow (age range: 44 to 78 years and the other with altered arterial flow (age range: 38 to 67 years. These groups were compared with a group formed by ten cadavers aged 18 to 25 years that were presumed to have been potent. Quantification of the smooth muscle fibers was done by means of an immunohistochemical study. RESULTS: The proportion of smooth muscle fiber found was 41.15% for the control group. The patients with erectile dysfunction and normal arterial flow presented 27.24% and those with altered arterial flow presented 25.74%; 19 patients presented at least one chronic disease or risk factor for erectile dysfunction, with prominence for diabetes mellitus, systemic arterial hypertension and smoking. CONCLUSION: Among patients with severe erectile dysfunction, the arterial flow on its own does not present interference in the proportion of smooth muscle fiber. The diminution of the proportion of smooth muscle fiber may result from chronic diseases and vascular risk factors.
Motion dependence of smooth pursuit eye movements in the marmoset.
Mitchell, Jude F; Priebe, Nicholas J; Miller, Cory T
2015-06-01
Smooth pursuit eye movements stabilize slow-moving objects on the retina by matching eye velocity with target velocity. Two critical components are required to generate smooth pursuit: first, because it is a voluntary eye movement, the subject must select a target to pursue to engage the tracking system; and second, generating smooth pursuit requires a moving stimulus. We examined whether this behavior also exists in the common marmoset, a New World primate that is increasingly attracting attention as a genetic model for mental disease and systems neuroscience. We measured smooth pursuit in two marmosets, previously trained to perform fixation tasks, using the standard Rashbass step-ramp pursuit paradigm. We first measured the aspects of visual motion that drive pursuit eye movements. Smooth eye movements were in the same direction as target motion, indicating that pursuit was driven by target movement rather than by displacement. Both the open-loop acceleration and closed-loop eye velocity exhibited a linear relationship with target velocity for slow-moving targets, but this relationship declined for higher speeds. We next examined whether marmoset pursuit eye movements depend on an active engagement of the pursuit system by measuring smooth eye movements evoked by small perturbations of motion from fixation or during pursuit. Pursuit eye movements were much larger during pursuit than from fixation, indicating that pursuit is actively gated. Several practical advantages of the marmoset brain, including the accessibility of the middle temporal (MT) area and frontal eye fields at the cortical surface, merit its utilization for studying pursuit movements. Copyright © 2015 the American Physiological Society.
Adaptive control of energy storage systems for power smoothing applications
DEFF Research Database (Denmark)
Meng, Lexuan; Dragicevic, Tomislav; Guerrero, Josep M.
2017-01-01
for systems with multiple ESS units to realize several objectives simultaneously including SoC limiting, SoC balancing and power smoothing. Experiment is conducted considering a pulsed load profile. The results demonstrate the effectiveness of the proposal concerning the mentioned control objectives.......Energy storage systems (ESSs) are desired and widely applied for power smoothing especially in systems with renewable generation and pulsed loads. High-pass-filter (HPF) is commonly applied in those applications in which the HPF extracts the high frequency fluctuating power and uses...
Modelling conditional correlations of asset returns: A smooth transition approach
DEFF Research Database (Denmark)
Silvennoinen, Annastiina; Teräsvirta, Timo
In this paper we propose a new multivariate GARCH model with time-varying conditional correlation structure. The time-varying conditional correlations change smoothly between two extreme states of constant correlations according to a predetermined or exogenous transition variable. An LM-test is d......In this paper we propose a new multivariate GARCH model with time-varying conditional correlation structure. The time-varying conditional correlations change smoothly between two extreme states of constant correlations according to a predetermined or exogenous transition variable. An LM...
Porcine Stomach Smooth Muscle Force Depends on History-Effects
Directory of Open Access Journals (Sweden)
André Tomalka
2017-10-01
Full Text Available The stomach serves as food reservoir, mixing organ and absorption area for certain substances, while continually varying its position and size. Large dimensional changes during ingestion and gastric emptying of the stomach are associated with large changes in smooth muscle length. These length changes might induce history-effects, namely force depression (FD following active muscle shortening and force enhancement (FE following active muscle stretch. Both effects have impact on the force generating capacity of the stomach, and thus functional relevance. However, less is known about history-effects and active smooth muscle properties of stomach smooth muscle. Thus, the aim of this study was to investigate biomechanical muscle properties as force-length and force-velocity relations (FVR of porcine stomach smooth muscle strips, extended by the analysis of history-effects on smooth muscle force. Therefore, in total n = 54 tissue strips were dissected in longitudinal direction from the ventral fundus of porcine stomachs. Different isometric, isotonic, and isokinetic contraction protocols were performed during electrical muscle stimulation. Cross-sectional areas (CSA of smooth muscles were determined from cryo-histological sections stained with Picrosirius Red. Results revealed that maximum smooth muscle tension was 10.4 ± 2.6 N/cm2. Maximum shortening velocity (Vmax and curvature factor (curv of the FVR were 0.04 ± 0.01 [optimum muscle length/s] and 0.36 ± 0.15, respectively. The findings of the present study demonstrated significant (P < 0.05 FD [up to 32% maximum muscle force (Fim] and FE (up to 16% Fim of gastric muscle tissue, respectively. The FE- and FD-values increased with increasing ramp amplitude. This outstanding muscle behavior is not accounted for in existing models so far and strongly supports the idea of a holistic reflection of distinct stomach structure and function. For the first time this study provides a comprehensive set of
Airway smooth muscle excitation-contraction coupling and airway hyperresponsiveness.
Hirota, Simon; Helli, Peter B; Catalli, Adriana; Chew, Allyson; Janssen, Luke J
2005-01-01
The primary complaints from patients with asthma pertain to function of airway smooth muscle (ASM) function including shortness of breath, wheezing, and coughing. Thus, it is imperative to better understand the mechanisms underlying excitation-contraction coupling in ASM. Here, we review the various signaling pathways underlying contraction in ASM, and then examine how these are altered in asthma and airway hyperresponsiveness (a hallmark feature of asthma). Throughout, we highlight how studies of vascular smooth muscle have helped or hindered progress in understanding ASM physiology and pathophysiology.
Methods and electrolytes for electrodeposition of smooth films
Zhang, Jiguang; Xu, Wu; Graff, Gordon L; Chen, Xilin; Ding, Fei; Shao, Yuyan
2015-03-17
Electrodeposition involving an electrolyte having a surface-smoothing additive can result in self-healing, instead of self-amplification, of initial protuberant tips that give rise to roughness and/or dendrite formation on the substrate and/or film surface. For electrodeposition of a first conductive material (C1) on a substrate from one or more reactants in an electrolyte solution, the electrolyte solution is characterized by a surface-smoothing additive containing cations of a second conductive material (C2), wherein cations of C2 have an effective electrochemical reduction potential in the solution lower than that of the reactants.
The smooth entropy formalism for von Neumann algebras
Energy Technology Data Exchange (ETDEWEB)
Berta, Mario, E-mail: berta@caltech.edu [Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125 (United States); Furrer, Fabian, E-mail: furrer@eve.phys.s.u-tokyo.ac.jp [Department of Physics, Graduate School of Science, University of Tokyo, Tokyo, Japan and Institute for Theoretical Physics, Leibniz University Hanover, Hanover (Germany); Scholz, Volkher B., E-mail: scholz@phys.ethz.ch [Institute for Theoretical Physics, ETH Zurich, Zurich (Switzerland)
2016-01-15
We discuss information-theoretic concepts on infinite-dimensional quantum systems. In particular, we lift the smooth entropy formalism as introduced by Renner and collaborators for finite-dimensional systems to von Neumann algebras. For the smooth conditional min- and max-entropy, we recover similar characterizing properties and information-theoretic operational interpretations as in the finite-dimensional case. We generalize the entropic uncertainty relation with quantum side information of Tomamichel and Renner and discuss applications to quantum cryptography. In particular, we prove the possibility to perform privacy amplification and classical data compression with quantum side information modeled by a von Neumann algebra.
Inhibitory action of relaxin on human cervical smooth muscle.
Norström, A; Bryman, I; Wiqvist, N; Sahni, S; Lindblom, B
1984-09-01
The influence of purified porcine relaxin on contractility of human cervical smooth muscle was investigated in vitro. Strips of cervical tissue were obtained by needle biopsy from pregnant and nonpregnant women and were mounted in a superfused organ chamber for isometric measurement of contractile activity. Relaxin (0.005-25 micrograms/ml) inhibited the spontaneous contractions in cervical strips from 18% of nonpregnant, 68% of early pregnant, and in 100% of term pregnant women. These results indicate that relaxin has an inhibitory action on cervical smooth muscle and that this effect is more constantly detected as pregnancy proceeds.
Smooth torque speed characteristic of switched reluctance motors
DEFF Research Database (Denmark)
Zeng, Hui; Chen, Zhe; Chen, Hao
2014-01-01
The torque ripple of switched reluctance motors (SRMs) is the main disadvantage that limits the industrial application of these motors. Although several methods for smooth-toque operation (STO) have been proposed, STO works well only within a certain torque and speed range because of the constrai......The torque ripple of switched reluctance motors (SRMs) is the main disadvantage that limits the industrial application of these motors. Although several methods for smooth-toque operation (STO) have been proposed, STO works well only within a certain torque and speed range because...
Adaptive spectrum decision framework for heterogeneous dynamic spectrum access networks
CSIR Research Space (South Africa)
Masonta, M
2015-09-01
Full Text Available Spectrum decision is the ability of a cognitive radio (CR) system to select the best available spectrum band to satisfy dynamic spectrum access network (DSAN) users¿ quality of service (QoS) requirements without causing harmful interference...
Kordilla, J.; Tartakovsky, A. M.; Geyer, T.
2014-12-01
Unsaturated flow in fractured porous media exhibits highly complex flow dynamics and a wide range of intermittent flow processes. Especially in wide aperture fractures, flow processes may be dominated by gravitational instead of capillary forces leading to a deviation from the classical volume effective approaches (Richard's equation, Van Genuchten type relationships). The existence of various flow modes such as droplets, rivulets, turbulent and adsorbed films is well known, however, their spatial and temporal distribution within fracture networks is still an open question partially due to the lack of appropriate modeling tools. With our work we want to gain a deeper understanding of the underlying flow and transport dynamics in unsaturated fractured media in order to support the development of more refined upscaled methods, applicable on catchment scales. We present pore- and fracture-scale flow simulations obtained with a Smoothed Particle Hydrodynamics (SPH) model. The model allows to simulate free-surface flow dynamics including the effect of surface tension for a wide range of wetting conditions. Several empirical and semi-analytical solutions are used to verify the model. We show that our results satisfy the empirical scaling laws for droplet velocity and critical contact angle. Due to the efficient generation of surface tension via particle-particle interaction forces the dynamic wetting of surfaces as well as the velocity enhancement of droplets on saturated surfaces can readily be obtained. Furthermore, we study the effect of surface roughness on droplet velocities. Lastly, we present flow and transport simulations in the presence of an adjacent porous matrix in order to investigate its influence on the fracture surface flow dynamics and transport across the matrix-fracture interface.
Genetics Home Reference: X-linked lissencephaly with abnormal genitalia
... genitalia). Additional signs and symptoms of XLAG include chronic diarrhea, periods of increased blood sugar (transient hyperglycemia), and ... in the pancreas plays a role in the chronic diarrhea and hyperglycemia experienced by individuals with XLAG. Learn ...
Abdallah, Wael A.
2012-11-05
Asphaltenes extracted from seven different crude oils representing different geological formations from around the globe were analyzed using the Raman spectroscopic technique. Each spectrum is fitted with four main peaks using the Gaussian function. On the basis of D1 and G bands of the Raman spectrum, asphaltene indicated an ordered structure with the presence of boundary defected edges. The average aromatic sheet size of the asphaltene molecules is estimated within the range of 1.52-1.88 nm, which represents approximately seven to eight aromatic fused rings. This estimation is based on the integrated intensity of D1 and G bands, as proposed by Tunistra and Koenig. The results here are in perfect agreement with so many other used techniques and indicate the potential applicability of Raman measurements to determine the average aromatic ring size and its boundary. © 2012 American Chemical Society.
Radio frequency spectrum management
Sujdak, E. J., Jr.
1980-03-01
This thesis is a study of radio frequency spectrum management as practiced by agencies and departments of the Federal Government. After a brief introduction to the international agency involved in radio frequency spectrum management, the author concentrates on Federal agencies engaged in frequency management. These agencies include the National Telecommunications and Information Administration (NTIA), the Interdepartment Radio Advisory Committee (IRAC), and the Department of Defense (DoD). Based on an analysis of Department of Defense frequency assignment procedures, recommendations are given concerning decentralizing military frequency assignment by delegating broader authority to unified commanders. This proposal includes a recommendation to colocate the individual Service frequency management offices at the Washington level. This would result in reduced travel costs, lower manpower requirements, and a common tri-Service frequency management data base.
1988-11-30
bands and space services since it accounts for carrier types , modulation and multiple access techniques, and regenerative repeaters that are not... TYPE OF REPORT 13b. TIME COVERED 14. DATE OF REPORT (Yeaw, Mont, Day) 15. PAGE COUNT Final FROM Dec87 TO Nov 88 1988 November 30 240 16. SUPPLEMENTARY...MILSATCOM, WARC, Spectrum Use 19,ABSTRACT (Continue on reverse it necessary and Identify by blod number) The objective of this task was to provide
AUTISM SPECTRUM DISORDERS (ASD)
Middha Akanksha; Kataria Sahil; Sandhu Premjeet; Kapoor Bhawna
2011-01-01
Autism or Autism Spectrum Disorders (ASD) is a serious neurological disorder affecting communication skills, social interactions, adaptability in an individual, and also causes dramatic changes in behavioral patterns. This condition typically lasts throughout one’s lifetime and affects both, children as well as adults. Research has shown a tenfold increase in autism cases over the past decade and still rising at an alarming pace. The origins of autism are not known even to modern science. Aut...
Mode spectrum and temporal soliton formation in optical microresonators
Herr, T; Jost, J D; Mirgorodskiy, I; Lihachev, G; Gorodetsky, M L; Kippenberg, T J
2013-01-01
The formation of temporal dissipative solitons in optical microresonators enables compact, high repetition rate sources of ultra-short pulses as well as low noise, broadband optical frequency combs with smooth spectral envelopes. Here we study the influence of the resonator mode spectrum on temporal soliton formation. Using frequency comb assisted diode laser spectroscopy, the measured mode structure of crystalline MgF2 resonators are correlated with temporal soliton formation. While an overal general anomalous dispersion is required, it is found that higher order dispersion can be tolerated as long as it does not dominate the resonator's mode structure. Mode coupling induced avoided crossings in the resonator mode spectrum are found to prevent soliton formation, when affecting resonator modes close to the pump laser. The experimental observations are in excellent agreement with numerical simulations based on the nonlinear coupled mode equations, which reveal the rich interplay of mode crossings and soliton f...
Dobos, L.; Budavári, T.; Csabai, I.; Szalay, A. S.
2008-10-01
We present the Filter and Spectrum Services consisting of easy-to-use web applications and web services for searching, plotting and managing large collections of spectral energy distribution data and filter profiles as well as for performing various scientific operations on spectra in a unified framework. The services provide keyword search, advanced query forms and SQL query possibilities for selecting spectra or bandpass curves which may be retrieved in a variety of file formats including XML, VOTable and ASCII. All SDSS DR1-DR5 spectra had been loaded into a database as well as the entire 2dF catalog that adds up to more than 2.5 million SEDs of about a million spatial objects, but registered users can upload their own data making it available for the rest of the community and are free to modify or delete them at any time. Theoretical catalogs, such as the Bruzual-Charlot stochastic burst model spectrum library (100k spectra) and the BaSeL stellar library are also available. Scientific services allow building rest-frame composite spectra out of selected spectra; calculating synthetic magnitudes by convolving spectra with an arbitrary set of bandpass curves of optical instrument filters to generate simulated photometric catalogs on-the-fly; galactic extinction correction, fitting of the continuum using different set of templates (Bruzual-Charlot '03 templates, SDSS eigenspectra), line fitting. All scientific functionalities are available from the web user interface and via the SOAP web services for programmers. MySpectrum is a cross-platform version of the spectrum web service for setting up your own spectrum repository. It integrates into the main service allowing easy access to your data for the whole VO community. The main idea behind our web services is to move scientific functionalities physically close to the database in order to spare network bandwidth. This way scientists may do research without setting up expensive hardware, downloading large datasets
Operational calculus and differential equations with infinitely smooth coefficients
Directory of Open Access Journals (Sweden)
Dennis Nemzer
1990-01-01
Full Text Available A subring MF of the field of Mikusiński operators is constructed as a countable union space. Some topological properties of MF are investigated. Then, the product of an infinitely differentiable function and an element of MF is given and is used to investigate operational equations with infinitely smooth coefficients.
Suppression of vascular smooth muscle cells' proliferation and ...
African Journals Online (AJOL)
This study aimed to determine the effects of valsartan on the proliferation and migration of isolated rat vascular smooth muscle cells (VSMCs) and the expression of phospho-p42/44 mitogen-activated protein kinase (MAPK) promoted by angiotensin II (Ang II). VSMCs from the rat thoracic aorta were cultured by ...
[Intrarenal smooth muscle: histology of a complex urodymamic machine].
Arias, L F; Ortiz-Arango, N
2013-03-01
To know better the microscopic arrangement of the bundles of smooth muscle in the human renal parenchyma, their distribution and anatomical relationships, trying to make a reconstruction of this muscular system. Five adult human kidneys and one fetal kidney were processed "in toto" with cross sections every 300μm. In the histological sections we identify the smooth muscle fibers trying to determine its insertion, course and anatomical relationship with other structures of the kidney tissue. There are bundles of smooth muscle fibers of variable thickness parallel to the edges of the medullary pyramids, bundles that surrounding the medulla in a spiral course, and bundles that accompany arcuate vessels, the latter being the most abundant and easy to identify. These groups of muscle fibers do not have a precise or constant insertion site, their periodicity is not homogeneous and they are not a direct extension of the muscle of the renal pelvis, although some bundles are in contact with it. There are also unusual and inconstant small muscle fibers no associated to vessels in the interstitium of the cortex and, exceptionally, in the medulla. There is a complex microscopic system of smooth muscle fibers that partially surround the renal medulla and are related to renal pelvic muscles without a direct continuity with them. Although this small muscular system is under-recognized, could be very important in urodynamics. Copyright © 2012 AEU. Published by Elsevier Espana. All rights reserved.
Wide-band array signal processing via spectral smoothing
Xu, Guanghan; Kailath, Thomas
1989-01-01
A novel algorithm for the estimation of direction-of-arrivals (DOA) of multiple wide-band sources via spectral smoothing is presented. The proposed algorithm does not require an initial DOA estimate or a specific signal model. The advantages of replacing the MUSIC search with an ESPRIT search are discussed.
Smooth Rényi Entropy of Ergodic Quantum Information Sources
Schoenmakers, Berry; Tjoelker, Jilles; Tuyls, Pim; Verbitskiy, Evgeny
2007-01-01
We investigate the recently introduced notion of smooth Rényi entropy for the case of ergodic information sources, thereby generalizing previous work which concentrated mainly on i.i.d. information sources. We will actually consider ergodic quantum information sources, of which ergodic classical
Smoothing depth maps for improved steroscopic image quality
Tam, Wa James; Alain, Guillaume; Zhang, Liang; Martin, Taali; Renaud, Ronald
2004-10-01
A technique to improve the image quality of stereoscopic pictures generated from depth maps (depth image based rendering or DIBR) is examined. In general, there are two fundamental problems with DIBR: a depth map could contain artifacts (e.g., noise or "blockiness") and there is no explicit information on how to render newly exposed regions ("holes") in the rendered image as a result of new virtual camera positions. We hypothesized that smoothing depth maps before rendering will not only minimize the effects of noise and distortions in the depth maps but will also reduce areas of newly exposed regions where potential artifacts can arise. A formal subjective assessment of four stereoscopic sequences of natural scenes was conducted with 23 viewers. The stereoscopic sequences consisted of source images for the left-eye view and rendered images for the right-eye view. The depth maps were smoothed with a Gaussian blur filter at different levels of strength before depth image based rendering. Results indicated that ratings of perceived image quality improved with increasing levels of smoothing of the depth maps. Even though the depth maps were smoothed, a negative effect on ratings of overall perceived depth quality was not found.
Wave Forces on a Vertical Smooth Cylinder in Directional Waves
DEFF Research Database (Denmark)
Høgedal, M.; Skourup, J.; Burcharth, H. F.
1994-01-01
In this paper the results from physical experiments with an instrumented cylinder conducted in laboratory environments are presented. The primary aim of the study has been to investigate the effect from wave directionality on the local and depth integrated maximum wave forces on a smooth vertical...
Smooth plains on Mercury. A comparison with Vesta.
Zambon, F.; Capaccioni, F.; Carli, C.; De Sanctis, M. C.; Filacchione, G.; Giacomini, L.
Mercury, the closest planet to the Sun, has been visited by the MESSENGER spacecraft \\citet{solomon2007}. After 3 years of orbit around Mercury a global coverage of the surface has been done revealing that ∼27% of Mercury's surface is covered by smooth plains \\citet{denevi2013}. Large part of Mercury's smooth plain (SP) seems to have volcanic origin. Different composition has been observed, most of the SP have a magnesian alkali-basalt-like composition, while some of them have been interpreted as ultramafic. A further 2% of smooth plains have been identified as Odin-type plains and represent the knobby and hummocky plains surrounding the Caloris basin \\citet{denevi2013}. Application of classification methods \\citet{adams2006} applied to color image data of the MESSENGER wide angle camera (MDIS-WAC) \\citet{MDIS} and a spectral analysis of the spec- trometer data (MASCS-VIRS) \\citet{MASCS} are useful to highlight the differences in composition of the smooth planes. A compa rison between Mercury's SP and those of other solar system bodies, such as Vesta \\citet{desanctis2012}, reveals useful to obtain information on the origin and the evolution of this bodies.
SMOOTH SPALLATION RESULTING FROM COLLISIONS OF COPPER PLATES
Zakharenko, I.
1988-01-01
The author examines the processes occuring during the collision of the metal plates with the speed 800-400 m/s. The experiment showed the formation of smooth cracks due to the collision of heat-treated copper plates with equal thickness.
Airway smooth muscle and fibroblasts in the pathogenesis of asthma
Johnson, Peter R A; Burgess, Janette K
2004-01-01
Asthma is a disease characterized by marked structural changes within the airway wall. These changes include deposition of extracellular matrix proteins and an increase in the numbers of airway smooth muscle cells and subepithelial fibroblasts. Both these cell types possess properties that would
A Semiclassical Calculation of Scars for a Smooth Potential
Provost, D; Provost, Daniel; Baranger, Michel
1993-01-01
Bogomolny's formula for energy-smoothed scars is applied for the first time to a non-specific, non-scalable Hamiltonian, a 2-D anharmonic oscillator. The semiclassical theory reproduces well the exact quantal results over a large spatial and energy range.
On a class of smooth Frechet subalgebras of C -algebras
Indian Academy of Sciences (India)
Proc. Indian Acad. Sci. (Math. Sci.) Vol. 123, No. 3, August 2013, pp. 393–413. c Indian Academy of Sciences. On a class of smooth Frechet subalgebras of C. ∗ ... Department of Mathematics, Sardar Patel University, Vallabh Vidyanagar, .... which was further developed in [5] at the level of generality of the present definition.
Launch Environment Water Flow Simulations Using Smoothed Particle Hydrodynamics
Vu, Bruce T.; Berg, Jared J.; Harris, Michael F.; Crespo, Alejandro C.
2015-01-01
This paper describes the use of Smoothed Particle Hydrodynamics (SPH) to simulate the water flow from the rainbird nozzle system used in the sound suppression system during pad abort and nominal launch. The simulations help determine if water from rainbird nozzles will impinge on the rocket nozzles and other sensitive ground support elements.
Water Flow Simulation using Smoothed Particle Hydrodynamics (SPH)
Vu, Bruce; Berg, Jared; Harris, Michael F.
2014-01-01
Simulation of water flow from the rainbird nozzles has been accomplished using the Smoothed Particle Hydrodynamics (SPH). The advantage of using SPH is that no meshing is required, thus the grid quality is no longer an issue and accuracy can be improved.
Postprocessing Fourier spectral methods: The case of smooth solutions
Energy Technology Data Exchange (ETDEWEB)
Garcia-Archilla, B. [Univ. Autonoma de Madrid (Spain). Dept. de Matematicas; Novo, J. [Univ. de Valladolid (Spain). Dept. de Matematica Aplicada y Computacion; Titi, E.S. [Univ. of California, Irvine, CA (United States)
1998-11-01
A postprocessing technique to improve the accuracy of Galerkin methods, when applied to dissipative partial differential equations, is examined in the particular case of smooth solutions. Pseudospectral methods are shown to perform poorly. This performance is analyzed and a refined postprocessing technique is proposed.
Comparative Analysis for Robust Penalized Spline Smoothing Methods
Directory of Open Access Journals (Sweden)
Bin Wang
2014-01-01
Full Text Available Smoothing noisy data is commonly encountered in engineering domain, and currently robust penalized regression spline models are perceived to be the most promising methods for coping with this issue, due to their flexibilities in capturing the nonlinear trends in the data and effectively alleviating the disturbance from the outliers. Against such a background, this paper conducts a thoroughly comparative analysis of two popular robust smoothing techniques, the M-type estimator and S-estimation for penalized regression splines, both of which are reelaborated starting from their origins, with their derivation process reformulated and the corresponding algorithms reorganized under a unified framework. Performances of these two estimators are thoroughly evaluated from the aspects of fitting accuracy, robustness, and execution time upon the MATLAB platform. Elaborately comparative experiments demonstrate that robust penalized spline smoothing methods possess the capability of resistance to the noise effect compared with the nonrobust penalized LS spline regression method. Furthermore, the M-estimator exerts stable performance only for the observations with moderate perturbation error, whereas the S-estimator behaves fairly well even for heavily contaminated observations, but consuming more execution time. These findings can be served as guidance to the selection of appropriate approach for smoothing the noisy data.
beta-Catenin regulates airway smooth muscle contraction
Jansen, Sepp R.; Van Ziel, Anna M.; Baarsma, Hoeke A.; Gosens, Reinoud
Jansen SR, Van Ziel AM, Baarsma HA, Gosens R. beta-Catenin regulates airway smooth muscle contraction. Am J Physiol Lung Cell Mol Physiol 299: L204-L214, 2010. First published May 14, 2010; doi:10.1152/ajplung.00020.2010.-beta-Catenin is an 88-kDa member of the armadillo family of proteins that is
Technique for smoothing free-flight oscillation data.
CSIR Research Space (South Africa)
Beyers, ME
1975-01-01
Full Text Available A technique based on superposition of tricyclic solutions has been proposed for smoothing free-flight angular motion. When incorporated into a conventional tricyclic data reduction program, the method is convenient to use and does not require a...
Adaptive Smoothed Finite Elements (ASFEM) for history dependent material models
Quak, W.; van den Boogaard, Antonius H.; Menary, Gary
2011-01-01
A successful simulation of a bulk forming process with finite elements can be difficult due to distortion of the finite elements. Nodal smoothed Finite Elements (NSFEM) are an interesting option for such a process since they show good distortion insensitivity and moreover have locking-free behavior
Congenital smooth muscle hamartoma of the palpebral conjunctiva.
Mora, L Evelyn; Rodríguez-Reyes, Abelardo A; Vera, Ana M; Rubio, Rosa Isela; Mayorquín-Ruiz, Mariana; Salcedo, Guillermo
2012-01-01
Smooth muscle hamartoma is defined as a disorganized focus or an overgrowth of mature smooth muscle, generally with low capacity of autonomous growth and benign behavior. The implicated tissues are mature and proliferate in a disorganized fashion. A healthy 5-day-old Mexican boy was referred to the authors' hospital in México city for evaluation of a "cystic" lesion of the right eye that had been noted since birth. The pregnancy and delivery were unremarkable. On physical examination, there was a reddish-pink soft lesion with a tender "cystic" appearance, which was probably emerging from the upper eyelid conjunctiva, which measured 2.7 cm in its widest diameter and transilluminated. Ultrasound imaging revealed an anterior "cystic" lesion with normally formed phakic eye. An excisional biopsy was performed, and the lesion was dissected from the upper tarsal subconjunctival space. Subsequent histologic and immunohistochemical findings were consistent with the diagnosis of congenital smooth muscle hamartoma (CSMH) of the tarsal conjunctiva. The authors' research revealed that only one case of CSMH localized in the conjunctiva (Roper GJ, Smith MS, Lueder GT. Congenital smooth muscle hamartoma of the conjunctival fornix. Am J Ophthalmol. 1999;128:643-4) has been reported to date in the literature. To the best of the authors' knowledge, this current case would be the second case reported of CSMH in this anatomic location. Therefore, the authors' recommendation is to include CSMH in the differential diagnosis of a cystic mass that presents in the fornix and palpebral conjunctiva.
Smooth and rough boundaries in turbulent Taylor-Couette flow
van den Berg, Th.H.; Doering, Charles R.; Lohse, Detlef; Lathrop, Daniel P.
2003-01-01
We examine the torque required to drive the smooth or rough cylinders in turbulent Taylor-Couette flow. With rough inner and outer walls the scaling of the dimensionless torque G is found to be consistent with pure Kolmogorov scaling G~Re2. The results are interpreted within the Grossmann-Lohse
Vascular smooth muscle sensitivity to varying oxygen tensions, Bay ...
African Journals Online (AJOL)
I this our study, using rat tail artery activate by nordrenaline and potassium chloride in thepresence of Bay K. 8644 and nifedipine at different oxygen levels, we showed that desensitization of the responses of the vscular smooth muscle occurred. It was evident that the underlying basis of vascular reponses observed with ...
Peptostreptococcus micros smooth and rough genotypes in periodontitis and gingivitis
Kremer, BHA; Loos, BG; van der Velden, U; van Winkelhoff, AJ; Craandijk, J; Bulthuis, HM; Hutter, J; Varoufaki, AS; van Steenbergen, TJM
Background: Two genotypes can be distinguished within the species Peptostreptococcus micros: a smooth (Sm) and a rough (Rg) type. To date no systematic study has been performed on the prevalence and proportion of both types in untreated periodontitis patients and subjects without destructive
An adaptive filter for smoothing noisy radar images
Frost, V. S.; Stiles, J. A.; Shanmugam, K. S.; Holtzman, J. C.; Smith, S. A.
1981-01-01
A spatial domain adaptive Wiener filter for smoothing radar images corrupted by multiplicative noise is presented. The filter is optimum in a minimum mean squared error sense, computationally efficient, and preserves edges in the image better than other filters. The proposed algorithm can also be used for processing optical images with illumination variations that have a multiplicative effect.
Upsilon-quaternion splines for the smooth interpolation of orientations.
Nielson, Gregory M
2004-01-01
We present a new method for smoothly interpolating orientation matrices. It is based upon quaternions and a particular construction of upsilon-spline curves. The new method has tension parameters and variable knot (time) spacing which both prove to be effective in designing and controlling key frame animations.
Smoothed analysis of partitioning algorithms for Euclidean functionals
Bläser, Markus; Manthey, Bodo; Rao, B.V. Raghavendra
2013-01-01
Euclidean optimization problems such as TSP and minimum-length matching admit fast partitioning algorithms that compute near-optimal solutions on typical instances. In order to explain this performance, we develop a general framework for the application of smoothed analysis to partitioning
Smoothed analysis of partitioning algorithms for Euclidean functionals
Bläser, Markus; Manthey, Bodo; Rao, B.V. Raghavendra; Dehne, F.; Iacono, J.; Sack, J.-R.
2011-01-01
Euclidean optimization problems such as TSP and minimum-length matching admit fast partitioning algorithms that compute near-optimal solutions on typical instances. We develop a general framework for the application of smoothed analysis to partitioning algorithms for Euclidean optimization problems.
Mechanism of kolaviron-induced relaxation of rabbit aortic smooth ...
African Journals Online (AJOL)
Mechanism of kolaviron-induced relaxation of rabbit aortic smooth muscle. 1Uche O.K.* Baseerah E.B. 2Anukam C.K.. 1Department of Physiology and 2TWAS Genomic Research Unit, Department of Medical Laboratory Sciences,. School of Basic Medical Sciences, University of Benin, PMB 1154 Benin City, Nigeria.
An Error Detection and Smoothing Algorithm for Infrared Data.
1986-04-01
34A Dynamic Programming Technique for Nonlinear ’R. L. Lucke, A. P. Schaum , J. C. Kershenstein, J. Michalo- Smoothing", Proc. IEEE International Conf...UNIVERSITY APPLIED PHYSICS LABORATORY LAUREL. MARYLAND REFERENCES 1R. L. Lucke, A. P. Schaum , J. C. Kershenstein, J. 7 H. Ney, "A Dynamic Programming
Smooth transition autoregressive models - A survey of recent developments
D.J.C. van Dijk (Dick); T. Terasvirta; Ph.H.B.F. Franses (Philip Hans)
2000-01-01
textabstractThis paper surveys recent developments related to the smooth transition autoregressive [STAR] time series model and several of its variants. We put emphasis on new methods for testing for STAR nonlinearity, model evaluation, and forecasting. Several useful extensions of the basic STAR
Vascular effects of 3-carbomethoxypyridine on rabbit aortic smooth ...
African Journals Online (AJOL)
Background: 3-Carbomethoxypyridine (3-CMP) is a methyl nicotinate that has been isolated and characterized from one of the alkaloidal fractions of Pyrenacantha staudtii. No literature is available on its vascular action. The goal of this study was to characterize the mechanism of action of 3-CMP on rabbit aortic smooth ...
Estimate of K-functionals and modulus of smoothness constructed ...
Indian Academy of Sciences (India)
Introduction and preliminaries. In [2], Belkina and Platonov proved the equivalence theorem for a K-functional and a modulus of smoothness for the Dunkl transform in the Hilbert space L2(R, |x|2α+1. ), α > −1/2, using a Dunkl translation operator. In this paper, we prove the analog of this result (see [2]) in the Hilbert space.
Association of smooth muscle cell tissue factor with caveolae
Mulder, AB; Smit, JW; Bom, VJJ; Blom, NR; Ruiters, MHJ; Halie, MR; vanderMeer, J
1996-01-01
There is still no satisfactory explanation for the low catalytic activity of tissue factor (TF)/factor VII(a) complexes towards coagulation factor X, as found on the apical surface side of cell layers. It has been hypothesized that TF exists in a latent form. Layers of cultured human smooth muscle
Conditional electron confinement in graphene via smooth magnetic fields
Le, Dai-Nam; Le, Van-Hoang; Roy, Pinaki
2018-02-01
In this article we discuss confinement of electrons in graphene via smooth magnetic fields which are finite everywhere on the plane. We shall consider two types of magnetic fields leading to systems which are conditionally exactly solvable and quasi exactly solvable. The bound state energies and wavefunctions in both cases have been found exactly.
Morinda lucida reduces contractility of isolated uterine smooth ...
African Journals Online (AJOL)
The present work investigated the effect of Morinda lucida (M. lucida) extract on isolated uterine smooth muscle of pregnant and non-pregnant mice. Pregnant and non-pregnant mice were pretreated with oral stilboesterol (0.1mg/kg body weight) and killed by cervical dislocation. Thin strips of the uterus were cut and ...
Evaluation of eigenvalues of a smooth potential via Schroedinger ...
Indian Academy of Sciences (India)
Evaluation of eigenvalues of a smooth potential via Schroedinger transmission across multi-step potential. BASUDEB SAHU1,∗, BIDHUBHUSAN SAHU1 and SANTOSH K AGARWALLA2. 1Department of Physics, North Orissa University, Baripada 757 003, India. 2Department of Applied Physics and Ballistics, Fakir Mohan ...
Improving convergence in smoothed particle hydrodynamics simulations without pairing instability
Dehnen, Walter; Aly, Hossam
2012-09-01
The numerical convergence of smoothed particle hydrodynamics (SPH) can be severely restricted by random force errors induced by particle disorder, especially in shear flows, which are ubiquitous in astrophysics. The increase in the number NH of neighbours when switching to more extended smoothing kernels at fixed resolution (using an appropriate definition for the SPH resolution scale) is insufficient to combat these errors. Consequently, trading resolution for better convergence is necessary, but for traditional smoothing kernels this option is limited by the pairing (or clumping) instability. Therefore, we investigate the suitability of the Wendland functions as smoothing kernels and compare them with the traditional B-splines. Linear stability analysis in three dimensions and test simulations demonstrate that the Wendland kernels avoid the pairing instability for all NH, despite having vanishing derivative at the origin (disproving traditional ideas about the origin of this instability; instead, we uncover a relation with the kernel Fourier transform and give an explanation in terms of the SPH density estimator). The Wendland kernels are computationally more convenient than the higher order B-splines, allowing large NH and hence better numerical convergence (note that computational costs rise sublinear with NH). Our analysis also shows that at low NH the quartic spline kernel with NH ≈ 60 obtains much better convergence than the standard cubic spline.
Mechanism of kolaviron-induced relaxation of rabbit aortic smooth ...
African Journals Online (AJOL)
induced relaxation on contractile responses in ring preparations of vascular smooth muscle (VSM) of the rabbit aorta in vitro, in standard laboratory organ bath procedure. Following Phenylephrine (PE) (10-7M), or high-K+ (80 mMK+) PSS induced ...
A remark on smooth images of Banach spaces
Czech Academy of Sciences Publication Activity Database
Hájek, Petr Pavel; Johanis, M.
2018-01-01
Roč. 458, č. 2 (2018), s. 1307-1313 ISSN 0022-247X R&D Projects: GA ČR GA16-07378S Institutional support: RVO:67985840 Keywords : smooth surjections Subject RIV: BA - General Mathematics Impact factor: 1.064, year: 2016 http://www.sciencedirect.com/science/article/pii/S0022247X17309186?via%3Dihub
Smoothed analysis of left-to-right maxima with applications
Damerow, Valentina; Manthey, Bodo; Meyer auf der Heide, Friedhelm; Räcke, Heide Harald; Scheideler, Christian; Sohler, Christian; Tantau, Till
A left-to-right maximum in a sequence of n numbers $s_1, ..., s_n$ is a number that is strictly larger than all preceding numbers. In this paper we present a smoothed analysis of the number of left-to-right maxima in the presence of additive random noise. We show that for every sequence of $n$
Particle motions in oscillatory flow over a smooth bed
DEFF Research Database (Denmark)
Jensen, Karsten Lindegård; Sumer, B. Mutlu; Fredsøe, Jørgen
2014-01-01
This study investigates particle motions near the bed in an oscillating tunnel with a smooth bed. Trajectories of a heavy particle were recorded in two dimensions (horizontal and vertical) and in time. The wave boundary layer Reynolds number is Re = 520000. Kinematical quantities such as the prob...
Phenotype modulation of airway smooth muscle in asthma
Wright, David B.; Trian, Thomas; Siddiqui, Sana; Pascoe, Chris D.; Johnson, Jill R.; Dekkers, Bart G. J.; Dakshinamurti, Shyamala; Bagchi, Rushita; Burgess, Janette K.; Kanabar, Varsha; Ojo, Oluwaseun O.
The biological responses of airway smooth muscle (ASM) are diverse, in part due to ASM phenotype plasticity. ASM phenotype plasticity refers to the ability of ASM cells to change the degree of a variety of functions, including contractility, proliferation, migration and secretion of inflammatory
Airway smooth muscle cells : regulators of airway inflammation
Zuyderduyn, Suzanne
2007-01-01
Airways from asthmatic subjects are more responsive to bronchoconstrictive stimuli than airways from healthy subjects. Airway smooth muscle (ASM) cells mediate contraction of the airways by responding to the bronchoconstrictive stimuli, which was thought to be the primary role of ASM cells. In this
Airway smooth muscle dysfunction in Pompe (Gaa-/- ) mice.
Keeler, Allison M; Liu, Donghai; Zieger, Marina; Xiong, Lang; Salemi, Jeffrey; Bellvé, Karl; Byrne, Barry J; Fuller, David D; ZhuGe, Ronghua; ElMallah, Mai K
2017-06-01
Pompe disease is an autosomal recessive disorder caused by a deficiency of acid α-glucosidase (GAA), an enzyme responsible for hydrolyzing lysosomal glycogen. Deficiency of GAA leads to systemic glycogen accumulation in the lysosomes of skeletal muscle, motor neurons, and smooth muscle. Skeletal muscle and motor neuron pathology are known to contribute to respiratory insufficiency in Pompe disease, but the role of airway pathology has not been evaluated. Here we propose that GAA enzyme deficiency disrupts the function of the trachea and bronchi and this lower airway pathology contributes to respiratory insufficiency in Pompe disease. Using an established mouse model of Pompe disease, the Gaa-/- mouse, we compared histology, pulmonary mechanics, airway smooth muscle (ASM) function, and calcium signaling between Gaa-/- and age-matched wild-type (WT) mice. Lysosomal glycogen accumulation was observed in the smooth muscle of both the bronchi and the trachea in Gaa-/- but not WT mice. Furthermore, Gaa-/- mice had hyporesponsive airway resistance and bronchial ring contraction to the bronchoconstrictive agents methacholine (MCh) and potassium chloride (KCl) and to a bronchodilator (albuterol). Finally, calcium signaling during bronchiolar smooth muscle contraction was impaired in Gaa-/- mice indicating impaired extracellular calcium influx. We conclude that GAA enzyme deficiency leads to glycogen accumulation in the trachea and bronchi and impairs the ability of lower ASM to regulate calcium and respond appropriately to bronchodilator or constrictors. Accordingly, ASM dysfunction may contribute to respiratory impairments in Pompe disease. Copyright © 2017 the American Physiological Society.
HSP20 phosphorylation and airway smooth muscle relaxation
Directory of Open Access Journals (Sweden)
Mariam Ba
2009-06-01
Full Text Available Mariam Ba1, Cherie A Singer1, Manoj Tyagi2, Colleen Brophy3, Josh E Baker4, Christine Cremo4, Andrew Halayko5, William T Gerthoffer21Department of Pharmacology, University of Nevada School of Medicine, Reno, NV, USA; 2Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL, USA; 3Harrington Department of Biochemistry, Arizona State University, Tempe, AZ, USA; 4Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV, USA; 5Departments of Physiology and Internal Medicine, University of Manitoba, Winnipeg, MB, CanadaAbstract: HSP20 (HSPB6 is a small heat shock protein expressed in smooth muscles that is hypothesized to inhibit contraction when phosphorylated by cAMP-dependent protein kinase. To investigate this hypothesis in airway smooth muscle (ASM we showed that HSP20 was constitutively expressed as well as being inducible in cultured hASM cells by treatment with 1 µM isoproterenol or 10 µM salmeterol. In contrast, a mixture of proinflammatory mediators (interleukin-1β, tumor necrosis factor α, and interferon γ inhibited expression of HSP20 by about 50% in 48 hours. To determine whether phosphorylation of HSP20 is sufficient to induce relaxation, canine tracheal smooth muscle was treated with a cell permeant phosphopeptide that mimics the phosphorylation of HSP20. The HSP20 phosphopeptide antagonized carbacholinduced contraction by 60% with no change in myosin light chain phosphorylation. Recombinant full length HSP20 inhibited skeletal actin binding to smooth muscle myosin subfragment 1 (S1, and recombinant cell permeant TAT-HSP20 S16D mutant reduced F-actin filaments in cultured hASM cells. Carbachol stimulation of canine tracheal smooth muscle tissue caused redistribution of HSP20 from large macromolecular complexes (200–500 kDa to smaller complexes (<60 kDa. The results are consistent with HSP20 expression and macromolecular structure being dynamically regulated in airway
Full-waveform inversion using a nonlinearly smoothed wavefield
Li, Yuanyuan
2017-12-08
Conventional full-waveform inversion (FWI) based on the least-squares misfit function faces problems in converging to the global minimum when using gradient methods because of the cycle-skipping phenomena. An initial model producing data that are at most a half-cycle away from the observed data is needed for convergence to the global minimum. Low frequencies are helpful in updating low-wavenumber components of the velocity model to avoid cycle skipping. However, low enough frequencies are usually unavailable in field cases. The multiplication of wavefields of slightly different frequencies adds artificial low-frequency components in the data, which can be used for FWI to generate a convergent result and avoid cycle skipping. We generalize this process by multiplying the wavefield with itself and then applying a smoothing operator to the multiplied wavefield or its square to derive the nonlinearly smoothed wavefield, which is rich in low frequencies. The global correlation-norm-based objective function can mitigate the dependence on the amplitude information of the nonlinearly smoothed wavefield. Therefore, we have evaluated the use of this objective function when using the nonlinearly smoothed wavefield. The proposed objective function has much larger convexity than the conventional objective functions. We calculate the gradient of the objective function using the adjoint-state technique, which is similar to that of the conventional FWI except for the adjoint source. We progressively reduce the smoothing width applied to the nonlinear wavefield to naturally adopt the multiscale strategy. Using examples on the Marmousi 2 model, we determine that the proposed FWI helps to generate convergent results without the need for low-frequency information.
Rouhi, Amirreza; Chung, Daniel; Hutchins, Nicholas
2017-11-01
Direct numerical simulations (DNSs) are reported for open channel flow over streamwise-alternating patches of smooth and fully rough walls. Owing to the streamwise periodicity, the flow configuration is composed of a step change from smooth to rough, and a step change from rough to smooth. The friction Reynolds number varies from 443 over the smooth patch to 715 over the rough patch. The flow is thoroughly studied by mean and fluctuation profiles, and spectrograms. The detailed flow from DNS reveals discrepancies of up to 50% among the various definitions of the internal-layer thickness, with apparent power-law exponents differing by up to 60%. The definition based on the logarithmic slope of the velocity profile, as proposed by Chamorro et al. (Boundary-Layer Meteorol., vol. 130, 2009, pp. 29-41), is most consistent with the physical notion of the internal layer; this is supported by the defect similarity based on this internal-layer thickness, and the streamwise homogeneity of the dissipation length-scale within this internal layer. The statistics inside this internal-layer, and the growth of the internal layer itself, are minimally affected by the streamwise periodicity when the patch length is at least six times the channel height.
Modulating activity of M1 receptor to the reaction of ileal smooth muscle
Directory of Open Access Journals (Sweden)
Izabela Glaza
2011-08-01
Full Text Available Background:The subject of the study was determination of the effect of drugs on ileal smooth muscle contraction induced by activation of M1 type muscarinic receptors. Drugs that have an effect on muscarinic receptors are divided to agonists, with close ties to the receptor and high internal activity and antagonists, with no internal activity. Conducted experiments tested interactions between a broad-spectrum agonist of muscarinic receptors, carbachol and a selective muscarinic receptor antagonist of M1 type, pirenzepine.Material/Methods:Testing was conducted on tissues isolated from rat’s intestine. Male Wistar rats with weight between 220 g and 360 g were anesthetized by intraperitoneal injection of urethane (120 mg/kg. Concentration-effect curves were determined with the use of cumulated concentration method, in accordance with the van Rossum method (1963 in Kenakin modification (2006.Results:The purpose of the study was determination of concentration-effect curves for carbachol. This curve was compared with the curve of receptor occupation depending on concentration of this drug. Based on concentration-effect curves, the average value of EC50 was calculated for carbachol, amounting to 2.44×10–6 [M/l].Conclusions:The results confirmed that atropine is effective in stopping contractions caused by carbachol, meeting the conditions of competitive antagonists. Atropine caused the shift of curves for carbachol to the right. Pirenzepine, selectively blocking muscarinic receptors of M1 type gave similar results. It was proved that in the preparation of gastric fundus smooth muscle, M1 type receptors occur not only presynaptically, but also postsynaptically.
WaVPeak: Picking NMR peaks through wavelet-based smoothing and volume-based filtering
Liu, Zhi
2012-02-10
Motivation: Nuclear magnetic resonance (NMR) has been widely used as a powerful tool to determine the 3D structures of proteins in vivo. However, the post-spectra processing stage of NMR structure determination usually involves a tremendous amount of time and expert knowledge, which includes peak picking, chemical shift assignment and structure calculation steps. Detecting accurate peaks from the NMR spectra is a prerequisite for all following steps, and thus remains a key problem in automatic NMR structure determination. Results: We introduce WaVPeak, a fully automatic peak detection method. WaVPeak first smoothes the given NMR spectrum by wavelets. The peaks are then identified as the local maxima. The false positive peaks are filtered out efficiently by considering the volume of the peaks. WaVPeak has two major advantages over the state-of-the-art peak-picking methods. First, through wavelet-based smoothing, WaVPeak does not eliminate any data point in the spectra. Therefore, WaVPeak is able to detect weak peaks that are embedded in the noise level. NMR spectroscopists need the most help isolating these weak peaks. Second, WaVPeak estimates the volume of the peaks to filter the false positives. This is more reliable than intensity-based filters that are widely used in existing methods. We evaluate the performance of WaVPeak on the benchmark set proposed by PICKY (Alipanahi et al., 2009), one of the most accurate methods in the literature. The dataset comprises 32 2D and 3D spectra from eight different proteins. Experimental results demonstrate that WaVPeak achieves an average of 96%, 91%, 88%, 76% and 85% recall on 15N-HSQC, HNCO, HNCA, HNCACB and CBCA(CO)NH, respectively. When the same number of peaks are considered, WaVPeak significantly outperforms PICKY. The Author(s) 2012. Published by Oxford University Press.
Directory of Open Access Journals (Sweden)
Ichiro Yajima
Full Text Available BACKGROUND: Patent ductus arteriosus is a life-threatening condition frequent in premature newborns but also present in some term infants. Current mouse models of this malformation generally lead to perinatal death, not reproducing the full phenotypic spectrum in humans, in whom genetic inheritance appears complex. The ductus arteriosus (DA, a temporary fetal vessel that bypasses the lungs by shunting the aortic arch to the pulmonary artery, is constituted by smooth muscle cells of distinct origins (SMC1 and SMC2 and many fewer melanocytes. To understand novel mechanisms preventing DA closure at birth, we evaluated the importance of cell fate specification in SMC that form the DA during embryonic development. Upon specific Tyr::Cre-driven activation of Wnt/β-catenin signaling at the time of cell fate specification, melanocytes replaced the SMC2 population of the DA, suggesting that SMC2 and melanocytes have a common precursor. The number of SMC1 in the DA remained similar to that in controls, but insufficient to allow full DA closure at birth. Thus, there was no cellular compensation by SMC1 for the loss of SMC2. Mice in which only melanocytes were genetically ablated after specification from their potential common precursor with SMC2, demonstrated that differentiated melanocytes themselves do not affect DA closure. Loss of the SMC2 population, independent of the presence of melanocytes, is therefore a cause of patent ductus arteriosus and premature death in the first months of life. Our results indicate that patent ductus arteriosus can result from the insufficient differentiation, proliferation, or contractility of a specific smooth muscle subpopulation that shares a common neural crest precursor with cardiovascular melanocytes.
Puig, Isabel; Champeval, Delphine; Kumasaka, Mayuko; Belloir, Elodie; Bonaventure, Jacky; Mark, Manuel; Yamamoto, Hiroaki; Taketo, Mark M.; Choquet, Philippe; Etchevers, Heather C.; Beermann, Friedrich; Delmas, Véronique; Monassier, Laurent; Larue, Lionel
2013-01-01
Background Patent ductus arteriosus is a life-threatening condition frequent in premature newborns but also present in some term infants. Current mouse models of this malformation generally lead to perinatal death, not reproducing the full phenotypic spectrum in humans, in whom genetic inheritance appears complex. The ductus arteriosus (DA), a temporary fetal vessel that bypasses the lungs by shunting the aortic arch to the pulmonary artery, is constituted by smooth muscle cells of distinct origins (SMC1 and SMC2) and many fewer melanocytes. To understand novel mechanisms preventing DA closure at birth, we evaluated the importance of cell fate specification in SMC that form the DA during embryonic development. Upon specific Tyr::Cre-driven activation of Wnt/β-catenin signaling at the time of cell fate specification, melanocytes replaced the SMC2 population of the DA, suggesting that SMC2 and melanocytes have a common precursor. The number of SMC1 in the DA remained similar to that in controls, but insufficient to allow full DA closure at birth. Thus, there was no cellular compensation by SMC1 for the loss of SMC2. Mice in which only melanocytes were genetically ablated after specification from their potential common precursor with SMC2, demonstrated that differentiated melanocytes themselves do not affect DA closure. Loss of the SMC2 population, independent of the presence of melanocytes, is therefore a cause of patent ductus arteriosus and premature death in the first months of life. Our results indicate that patent ductus arteriosus can result from the insufficient differentiation, proliferation, or contractility of a specific smooth muscle subpopulation that shares a common neural crest precursor with cardiovascular melanocytes. PMID:23382837
Next-to-leading order correction to the factorization limit of the radiation spectrum
Bondarenco, M. V.
2017-10-01
A next-to-leading order correction to the high-energy factorization limit of radiation spectrum from an ultra-relativistic electron scattering in an external field is evaluated. Generally, it does not express through scattering characteristics, and accounts for smoothness of the crossover between the initial and final electron asymptotes. A few examples of application of this formula are given, including bremsstrahlung in amorphous matter and undulator radiation.
Image decomposition: separation of texture from piecewise smooth content
Starck, Jean-Luc; Elad, Mikael; Donoho, David L.
2003-11-01
This paper presents a novel method for separating images into texture and piecewise smooth parts. The proposed approach is based on a combination of the Basis Pursuit Denoising (BPDN) algorithm and the Total-Variation (TV) regularization scheme. The basic idea promoted in this paper is the use of two appropriate dictionaries, one for the representation of textures, and the other for the natural scene parts. Each dictionary is designed for sparse representation of a particular type of image-content (either texture or piecewise smooth). The use of BPDN with the two augmented dictionaries leads to the desired separation, along with noise removal as a by-product. As the need to choose a proper dictionary for natural scene is very hard, a TV regularization is employed to better direct the separation process. Experimental results validate the algorithm's performance.
Modelling free surface flows with smoothed particle hydrodynamics
Directory of Open Access Journals (Sweden)
L.Di G.Sigalotti
2006-01-01
Full Text Available In this paper the method of Smoothed Particle Hydrodynamics (SPH is extended to include an adaptive density kernel estimation (ADKE procedure. It is shown that for a van der Waals (vdW fluid, this method can be used to deal with free-surface phenomena without difficulties. In particular, arbitrary moving boundaries can be easily handled because surface tension is effectively simulated by the cohesive pressure forces. Moreover, the ADKE method is seen to increase both the accuracy and stability of SPH since it allows the width of the kernel interpolant to vary locally in a way that only the minimum necessary smoothing is applied at and near free surfaces and sharp fluid-fluid interfaces. The method is robust and easy to implement. Examples of its resolving power are given for both the formation of a circular liquid drop under surface tension and the nonlinear oscillation of excited drops.
Smoothed particle hydrodynamics method from a large eddy simulation perspective
Di Mascio, A.; Antuono, M.; Colagrossi, A.; Marrone, S.
2017-03-01
The Smoothed Particle Hydrodynamics (SPH) method, often used for the modelling of the Navier-Stokes equations by a meshless Lagrangian approach, is revisited from the point of view of Large Eddy Simulation (LES). To this aim, the LES filtering procedure is recast in a Lagrangian framework by defining a filter that moves with the positions of the fluid particles at the filtered velocity. It is shown that the SPH smoothing procedure can be reinterpreted as a sort of LES Lagrangian filtering, and that, besides the terms coming from the LES convolution, additional contributions (never accounted for in the SPH literature) appear in the equations when formulated in a filtered fashion. Appropriate closure formulas are derived for the additional terms and a preliminary numerical test is provided to show the main features of the proposed LES-SPH model.
Smooth Horizonless Geometries Deep Inside the Black-Hole Regime.
Bena, Iosif; Giusto, Stefano; Martinec, Emil J; Russo, Rodolfo; Shigemori, Masaki; Turton, David; Warner, Nicholas P
2016-11-11
We construct the first family of horizonless supergravity solutions that have the same mass, charges, and angular momenta as general supersymmetric rotating D1-D5-P black holes in five dimensions. This family includes solutions with arbitrarily small angular momenta, deep within the regime of quantum numbers and couplings for which a large classical black hole exists. These geometries are well approximated by the black-hole solution, and in particular exhibit the same near-horizon throat. Deep in this throat, the black-hole singularity is resolved into a smooth cap. We also identify the holographically dual states in the N=(4,4) D1-D5 orbifold conformal field theory (CFT). Our solutions are among the states counted by the CFT elliptic genus, and provide examples of smooth microstate geometries within the ensemble of supersymmetric black-hole microstates.
Stochastic clustered-dot screen design for improved smoothness
Gupta, Madhur; Goyal, Puneet; Fischer, Mani; Staelin, Carl; Kashti, Tamar; Shacham, Omri; Allebach, Jan
2011-01-01
Printers employing electrophotographic technology typically use clustered-dot screening to avoid potential artifacts caused by unstable dot rendering. Periodic clustered-dot screens are quite smooth, but also suffer from periodic moiŕe artifacts due to interference with other color channels. Stochastic, clustered-dot screens provide an alternative solution. In this paper, we introduce a new approach for stochastic, clustered-dot screen design based on Direct Binary Search (DBS). The method differs from the conventional DBS in its use of a modified cost metric which was derived in an earlier work from using different filters in the initialization and update phases of DBS. The objective of the chosen approach is to design screen for improved print smoothness by generating a homogeneous distribution of compact, uniformly-sized clusters. The results include halftone of a screened folded-ramp, compared against a screen designed with a previous method.
Uremia modulates the phenotype of aortic smooth muscle cells
DEFF Research Database (Denmark)
Madsen, Marie; Pedersen, Annemarie Aarup; Albinsson, Sebastian
2017-01-01
BACKGROUND AND AIMS: Chronic kidney disease leads to uremia and markedly accelerates atherosclerosis. Phenotypic modulation of smooth muscle cells (SMCs) in the arterial media plays a key role in accelerating atherogenesis. The aim of this study was to investigate whether uremia per se modulates...... the phenotype of aortic SMCs in vivo. METHODS: Moderate uremia was induced by 5/6 nephrectomy in apolipoprotein E knockout (ApoE(-/-)) and wildtype C57Bl/6 mice. Plasma analysis, gene expression, histology, and myography were used to determine uremia-mediated changes in the arterial wall. RESULTS: Induction...... in the aortic media. In the aortic arch, mRNA and miRNA expression patterns were consistent with a uremia-mediated phenotypic modulation of SMCs; e.g. downregulation of myocardin, α-smooth muscle actin, and transgelin; and upregulation of miR146a. Notably, these expression patterns were observed after acute (2...
A new insight into the consistency of smoothed particle hydrodynamics
Sigalotti, Leonardo Di G; Klapp, Jaime; Vargas, Carlos A; Campos, Kilver
2016-01-01
In this paper the problem of consistency of smoothed particle hydrodynamics (SPH) is solved. A novel error analysis is developed in $n$-dimensional space using the Poisson summation formula, which enables the treatment of the kernel and particle approximation errors in combined fashion. New consistency integral relations are derived for the particle approximation which correspond to the cosine Fourier transform of the classically known consistency conditions for the kernel approximation. The functional dependence of the error bounds on the SPH interpolation parameters, namely the smoothing length $h$ and the number of particles within the kernel support ${\\cal{N}}$ is demonstrated explicitly from which consistency conditions are seen to follow naturally. As ${\\cal{N}}\\to\\infty$, the particle approximation converges to the kernel approximation independently of $h$ provided that the particle mass scales with $h$ as $m\\propto h^{\\beta}$, with $\\beta >n$. This implies that as $h\\to 0$, the joint limit $m\\to 0$, $...
Calcium-antagonist effects of quercetin on aortic smooth muscle.
Morales, M A; Lozoya, X
1994-08-01
Relaxation induced by quercetin was studied on aortic rings depolarized with KCl and on Ca2+ dependent aortic contraction. Quercetin's actions as a cyclooxygenase inhibitor were compared with those of indomethacin. To determine the possible effects of quercetin on internal Ca2+ mobilization, it was assayed on aortic muscle contracted with caffeine. Quercetin relaxes aortic smooth muscle contracted with KCl (RC50 = 1.8 x 10(-4) M) and induces a rightward displacement of Ca2+ curves. The relaxation induced by quercetin is higher than that produced by indomethacin, suggesting that its action is independent of cyclooxygenase inhibition. Caffeine-induced aortic contraction was not modified by quercetin, suggesting that its effect should not involve internal calcium modulation. Our results further support the thesis that the spasmolytic action of quercetin arises from its negative modulation of calcium entry to the smooth muscle.
A generalized transport-velocity formulation for smoothed particle hydrodynamics
Zhang, Chi; Hu, Xiangyu Y.; Adams, Nikolaus A.
2017-05-01
The standard smoothed particle hydrodynamics (SPH) method suffers from tensile instability. In fluid-dynamics simulations this instability leads to particle clumping and void regions when negative pressure occurs. In solid-dynamics simulations, it results in unphysical structure fragmentation. In this work the transport-velocity formulation of Adami et al. (2013) [14] is generalized for providing a solution of this long-standing problem. Other than imposing a global background pressure, a variable background pressure is used to modify the particle transport velocity and eliminate the tensile instability completely. Furthermore, such a modification is localized by defining a shortened smoothing length. The generalized formulation is suitable for fluid and solid materials with and without free surfaces. The results of extensive numerical tests on both fluid and solid dynamics problems indicate that the new method provides a unified approach for multi-physics SPH simulations.
A generalized transport-velocity formulation for smoothed particle hydrodynamics
Energy Technology Data Exchange (ETDEWEB)
Zhang, Chi; Hu, Xiangyu Y., E-mail: xiangyu.hu@tum.de; Adams, Nikolaus A.
2017-05-15
The standard smoothed particle hydrodynamics (SPH) method suffers from tensile instability. In fluid-dynamics simulations this instability leads to particle clumping and void regions when negative pressure occurs. In solid-dynamics simulations, it results in unphysical structure fragmentation. In this work the transport-velocity formulation of Adami et al. (2013) is generalized for providing a solution of this long-standing problem. Other than imposing a global background pressure, a variable background pressure is used to modify the particle transport velocity and eliminate the tensile instability completely. Furthermore, such a modification is localized by defining a shortened smoothing length. The generalized formulation is suitable for fluid and solid materials with and without free surfaces. The results of extensive numerical tests on both fluid and solid dynamics problems indicate that the new method provides a unified approach for multi-physics SPH simulations.
Sarcoglycan subcomplex expression in normal human smooth muscle.
Anastasi, Giuseppe; Cutroneo, Giuseppina; Sidoti, Antonina; Rinaldi, Carmen; Bruschetta, Daniele; Rizzo, Giuseppina; D'Angelo, Rosalia; Tarone, Guido; Amato, Aldo; Favaloro, Angelo
2007-08-01
The sarcoglycan complex (SGC) is a multimember transmembrane complex interacting with other members of the dystrophin-glycoprotein complex (DGC) to provide a mechanosignaling connection from the cytoskeleton to the extracellular matrix. The SGC consists of four proteins (alpha, beta, gamma, and delta). A fifth sarcoglycan subunit, epsilon-sarcoglycan, shows a wider tissue distribution. Recently, a novel sarcoglycan, the zeta-sarcoglycan, has been identified. All reports about the structure of SGC showed a common assumption of a tetrameric arrangement of sarcoglycans. Addressing this issue, our immunofluorescence and molecular results showed, for the first time, that all sarcoglycans are always detectable in all observed samples. Therefore, one intriguing possibility is the existence of a pentameric or hexameric complex considering zeta-sarcoglycan of SGC, which could present a higher or lower expression of a single sarcoglycan in conformity with muscle type--skeletal, cardiac, or smooth--or also in conformity with the origin of smooth muscle.
Menthol inhibiting parasympathetic function of tracheal smooth muscle.
Wang, Hsing-Won; Liu, Shao-Cheng; Chao, Pin-Zhir; Lee, Fei-Peng
2016-01-01
Menthol is used as a constituent of food and drink, tobacco and cosmetics nowadays. This cold receptor agonist has been used as a nasal inhalation solution in the daily life. The effect of menthol on nasal mucosa in vivo is well known; however, the effect of the drug on tracheal smooth muscle has been rarely explored. Therefore, during administration of the drug for nasal symptoms, it might also affect the trachea via oral intake or inhalation. We used our preparation to test the effectiveness of menthol on isolated rat tracheal smooth muscle. A 5 mm long portion of rat trachea was submersed in 30 ml Krebs solution in a muscle bath at 37ºC. Changes in tracheal contractility in response to the application of a parasympathetic mimetic agent were measured using a transducer connected to a Pentium III computer equipped with polygraph software. The following assessments of menthol were performed: (1) effect on tracheal smooth muscle resting tension; (2) effect on contraction caused by 10 -6 M methacholine as a parasympathetic mimetic; (3) effect of the drug on electrically induced tracheal smooth muscle contractions. Results indicated that addition of a parasympathetic mimetic to the incubation medium caused the trachea to contract in a dose-dependent manner. Addition of menthol at doses of 10 -5 M or above elicited a relaxation response to 10 -6 M methacholine-induced contraction. Menthol could also inhibit electrical field stimulation (EFS) induced spike contraction. However, it alone had a minimal effect on the basal tension of trachea as the concentration increased. We concluded that the degree of drug-induced tracheal contraction or relaxation was dose-dependent. In addition, this study indicated that high concentrations of menthol might actually inhibit parasympathetic function of the trachea.
3D Reconstruction of Coronary Artery Vascular Smooth Muscle Cells
Tong Luo; Huan Chen; Kassab, Ghassan S.
2016-01-01
Aims The 3D geometry of individual vascular smooth muscle cells (VSMCs), which are essential for understanding the mechanical function of blood vessels, are currently not available. This paper introduces a new 3D segmentation algorithm to determine VSMC morphology and orientation. Methods and Results A total of 112 VSMCs from six porcine coronary arteries were used in the analysis. A 3D semi-automatic segmentation method was developed to reconstruct individual VSMCs from cell clumps as well a...
Metal diffusion in smoothed particle hydrodynamics simulations of dwarf galaxies
Williamson, David John; Martel, Hugo; Kawata, Daisuke
2016-01-01
We perform a series of smoothed particle hydrodynamics simulations of isolated dwarf galaxies to compare different metal mixing models. In particular, we examine the role of diffusion in the production of enriched outflows, and in determining the metallicity distributions of gas and stars. We investigate different diffusion strengths, by changing the pre-factor of the diffusion coefficient, by varying how the diffusion coefficient is calculated from the local velocity distribution, and by var...
Superluminal tunneling of microwaves in smoothly varying transmission lines.
Shvartsburg, A B; Marklund, M; Brodin, G; Stenflo, L
2008-07-01
Tunneling of microwaves through a smooth barrier in a transmission line is considered. In contrast to standard wave barriers, we study the case where the dielectric permittivity is positive, and the barrier is caused by the inhomogeneous dielectric profile. It is found that reflectionless, superluminal tunneling can take place for waves with a finite spectral width. The consequences of these findings are discussed, and an experimental setup testing our predictions is proposed.
Chaos and Exponentially Localized Eigenstates in Smooth Hamiltonian Systems
Santhanam, M S; Lakshminarayan, A
1998-01-01
We present numerical evidence to show that the wavefunctions of smooth classically chaotic Hamiltonian systems scarred by certain simple periodic orbits are exponentially localized in the space of unperturbed basis states. The degree of localization, as measured by the information entropy, is shown to be correlated with the local phase space structure around the scarring orbit; indicating sharp localization when the orbit undergoes a pitchfork bifurcation and loses stability.
Blink effects on ongoing smooth pursuit eye movements in humans.
Rambold, Holger; El Baz, Ieman; Helmchen, Christoph
2005-02-01
Blinks are known to affect eye movements, e.g., saccades, slow and fast vergence, and saccade-vergence interaction, in two ways: by superimposition of blink-associated eye movements and changes of the central premotor activity in the brainstem. The goal of this study was to determine, for the first time, the effects of trigeminal evoked blinks on ongoing smooth pursuit eye movements which could be related to visual sensory or premotor neuronal changes. This was compared to the effect of a target disappearing for 100-300 ms duration during ongoing smooth pursuit (blank paradigm) in order to control for the visual sensory effects of a blink. Eye and blink movements were recorded in eight healthy subjects with the scleral search coil technique. Blink-associated eye movements during the first 50% of the blink duration were non-linearly superimposed on the smooth pursuit eye movements. Immediately after the blink-associated eye movements, the pursuit velocity slowly decreased by an average of 3.2+/-2.1 degrees /s. This decrease was not dependent on the stimulus direction. The pursuit velocity decrease caused by blinks which occluded the pupil more than 50% could be explained mostly by blanking the visual target. However, small blinks that did not occlude the pupil (smooth pursuit velocity. Thus, this blink effect on pursuit velocity cannot be explained by blink-associated eye movements or by the blink having blanked the visual input. We propose that part of this effect might either be caused by incomplete visual suppression during blinks and/or a change in the activity of omnipause neurons.
Entering PIN codes by smooth pursuit eye movements
Cymek, Dietlind Helene; Venjakob, Antje Christine; Ruff, Stefan; Lutz, Otto Hans-Martin; Hofmann, Simon; Roetting, Matthias
2014-01-01
Despite its potential gaze interaction is still not a widely-used interaction concept. Major drawbacks as the calibration, strain of the eyes and the high number of false alarms are associated with gaze based interaction and limit its practicability for every-day human computer interaction. In this paper two experiments are described which use smooth pursuit eye movements on moving display buttons. The first experiment was conducted to extract an easy and fast interaction concept and at the s...
Smoothed particle hydrodynamics modelling of fluids and solids
Directory of Open Access Journals (Sweden)
Lobovský L.
2007-11-01
Full Text Available The study is concerned about the application of the smoothed particle hydrodynamics (SPH method within the computational fluid dynamics and elastodynamics. A brief description of the SPH model for an incompressible fluid and for an elastic solid is presented. The implemented model of incompressible fluid is tested for internal flows as well as for flows involving a free surface of the fluid. The implemented elastic solid model is examined during the simulation of the mechanical response of rubber rings.
Radial Basis Function Based Quadrature over Smooth Surfaces
2016-03-24
Stieltjessche Integrale und Harmonische Analyse,” Math . Ann., vol. 108, pp. 378–410, 1933. 12. I. J. Schoenberg, “Metric Spaces and Positive Definite Functions ...Fornberg, “Interpolation in the Limit of Increasingly Flat Radial Basis Functions ,” Comput. Math . Appl., vol. 43, pp. 413–422, 2002. 83 REPORT...Radial Basis Function Based Quadrature over Smooth Surfaces THESIS March 2016 Maloupu L. Watts, Second Lieutenant, USAF AFIT-ENC-MS-16-M-003
Accurate Position Estimation in Switched Reluctance Motor With Smooth Starting
Panda, Debiprasad; Ramarayanan, V
2000-01-01
This paper presents a novel method of position estimation for switched reluctance (SR) motors. The method is suitable from starting to full speed. It ensures smooth starting without initial hesitation. The method further proposes a better position estimating algorithm incorporating corrections for eddy current and mutual inductance effects. The algorithm is better suited in a digital control platform for its realisation. In the present work, a Texas Instruments made DSP (TMS320c50) is used fo...
Experimental model of human corpus cavernosum smooth muscle relaxation
Regadas, Rommel P.; Maria E. A. Moraes; Mesquita,Francisco J. C.; Joao B. G. Cerqueira; Gonzaga-Silva,Lucio F.
2010-01-01
PURPOSE: To describe a technique for en bloc harvesting of the corpus cavernosum, cavernous artery and urethra from transplant organ donors and contraction-relaxation experiments with corpus cavernosum smooth muscle. MATERIALS AND METHODS: The corpus cavernosum was dissected to the point of attachment with the crus penis. A 3 cm segment (corpus cavernosum and urethra) was isolated and placed in ice-cold sterile transportation buffer. Under magnification, the cavernous artery was dissected. Th...
A Robust Kalman Framework with Resampling and Optimal Smoothing
Thomas Kautz; Bjoern M. Eskofier
2015-01-01
The Kalman filter (KF) is an extremely powerful and versatile tool for signal processing that has been applied extensively in various fields. We introduce a novel Kalman-based analysis procedure that encompasses robustness towards outliers, Kalman smoothing and real-time conversion from non-uniformly sampled inputs to a constant output rate. These features have been mostly treated independently, so that not all of their benefits could be exploited at the same time. Here, we present a coherent...
Reuman, Daniel C; Gislason, Henrik; Barnes, Carolyn; Mélin, Frédéric; Jennings, Simon
2014-01-01
Distributions of species body sizes within a taxonomic group, for example, mammals, are widely studied and important because they help illuminate the evolutionary processes that produced these distributions. Distributions of the sizes of species within an assemblage delineated by geography instead of taxonomy (all the species in a region regardless of clade) are much less studied but are equally important and will illuminate a different set of ecological and evolutionary processes. We develop and test a mechanistic model of how diversity varies with body mass in marine ecosystems. The model predicts the form of the ‘diversity spectrum’, which quantifies the distribution of species' asymptotic body masses, is a species analogue of the classic size spectrum of individuals, and which we have found to be a new and widely applicable description of diversity patterns. The marine diversity spectrum is predicted to be approximately linear across an asymptotic mass range spanning seven orders of magnitude. Slope −0·5 is predicted for the global marine diversity spectrum for all combined pelagic zones of continental shelf seas, and slopes for large regions are predicted to lie between −0·5 and −0·1. Slopes of −0·5 and −0·1 represent markedly different communities: a slope of −0·5 depicts a 10-fold reduction in diversity for every 100-fold increase in asymptotic mass; a slope of −0·1 depicts a 1·6-fold reduction. Steeper slopes are predicted for larger or colder regions, meaning fewer large species per small species for such regions. Predictions were largely validated by a global empirical analysis. Results explain for the first time a new and widespread phenomenon of biodiversity. Results have implications for estimating numbers of species of small asymptotic mass, where taxonomic inventories are far from complete. Results show that the relationship between diversity and body mass can be explained from the dependence of predation behaviour
Liquid-Infused Smooth Surface for Improved Condensation Heat Transfer.
Tsuchiya, Hirotaka; Tenjimbayashi, Mizuki; Moriya, Takeo; Yoshikawa, Ryohei; Sasaki, Kaichi; Togasawa, Ryo; Yamazaki, Taku; Manabe, Kengo; Shiratori, Seimei
2017-09-12
Control of vapor condensation properties is a promising approach to manage a crucial part of energy infrastructure conditions. Heat transfer by vapor condensation on superhydrophobic coatings has garnered attention, because dropwise condensation on superhydrophobic surfaces with rough structures leads to favorable heat-transfer performance. However, pinned condensed water droplets within the rough structure and a high thermodynamic energy barrier for nucleation of superhydrophobic surfaces limit their heat-transfer increase. Recently, slippery liquid-infused surfaces (SLIPS) have been investigated, because of their high water sliding ability and surface smoothness originating from the liquid layer. However, even on SLIPS, condensed water droplets are eventually pinned to degrade their heat-transfer properties after extended use, because the rough base layer is exposed as infused liquid is lost. Herein, we report a liquid-infused smooth surface named "SPLASH" (surface with π electron interaction liquid adsorption, smoothness, and hydrophobicity) to overcome the problems derived from the rough structures in previous approaches to obtain stable, high heat-transfer performance. The SPLASH displayed a maximum condensation heat-transfer coefficient that was 175% higher than that of an uncoated substrate. The SPLASH also showed higher heat-transfer performance and more stable dropwise condensation than superhydrophobic surfaces and SLIPS from the viewpoints of condensed water droplet mobility and the thermodynamic energy barrier for nucleation. The effects of liquid-infused surface roughness and liquid viscosity on condensation heat transfer were investigated to compare heat-transfer performance. This research will aid industrial applications using vapor condensation.
Efficient estimation of smooth distributions from coarsely grouped data.
Rizzi, Silvia; Gampe, Jutta; Eilers, Paul H C
2015-07-15
Ungrouping binned data can be desirable for many reasons: Bins can be too coarse to allow for accurate analysis; comparisons can be hindered when different grouping approaches are used in different histograms; and the last interval is often wide and open-ended and, thus, covers a lot of information in the tail area. Age group-specific disease incidence rates and abridged life tables are examples of binned data. We propose a versatile method for ungrouping histograms that assumes that only the underlying distribution is smooth. Because of this modest assumption, the approach is suitable for most applications. The method is based on the composite link model, with a penalty added to ensure the smoothness of the target distribution. Estimates are obtained by maximizing a penalized likelihood. This maximization is performed efficiently by a version of the iteratively reweighted least-squares algorithm. Optimal values of the smoothing parameter are chosen by minimizing Akaike's Information Criterion. We demonstrate the performance of this method in a simulation study and provide several examples that illustrate the approach. Wide, open-ended intervals can be handled properly. The method can be extended to the estimation of rates when both the event counts and the exposures to risk are grouped. © The Author 2015. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health.
Ensemble Kalman filtering with one-step-ahead smoothing
Raboudi, Naila F.
2018-01-11
The ensemble Kalman filter (EnKF) is widely used for sequential data assimilation. It operates as a succession of forecast and analysis steps. In realistic large-scale applications, EnKFs are implemented with small ensembles and poorly known model error statistics. This limits their representativeness of the background error covariances and, thus, their performance. This work explores the efficiency of the one-step-ahead (OSA) smoothing formulation of the Bayesian filtering problem to enhance the data assimilation performance of EnKFs. Filtering with OSA smoothing introduces an updated step with future observations, conditioning the ensemble sampling with more information. This should provide an improved background ensemble in the analysis step, which may help to mitigate the suboptimal character of EnKF-based methods. Here, the authors demonstrate the efficiency of a stochastic EnKF with OSA smoothing for state estimation. They then introduce a deterministic-like EnKF-OSA based on the singular evolutive interpolated ensemble Kalman (SEIK) filter. The authors show that the proposed SEIK-OSA outperforms both SEIK, as it efficiently exploits the data twice, and the stochastic EnKF-OSA, as it avoids observational error undersampling. They present extensive assimilation results from numerical experiments conducted with the Lorenz-96 model to demonstrate SEIK-OSA’s capabilities.
Potassium currents in cultured human pulmonary arterial smooth muscle cells.
Peng, W; Karwande, S V; Hoidal, J R; Farrukh, I S
1996-04-01
In this study, using whole cell and single-channel configurations of the patch-clamp technique, we characterized K+ currents (IK) in cultured human pulmonary arterial smooth muscle cells. The net whole cell outward membrane current (IKo) was activated at potentials positive to -60 mV. One component of IKo, IK(dr), was inhibited by 4-aminopyridine (4-AP) and high concentrations of tetraethylammonium (TEA) but was Ca2+ and charybdotoxin (CTX) insensitive. The other component of IKo, IK(Ca), was voltage and Ca2+ dependent and was inhibited by CTX and low concentrations of TEA. Activation of IKo in single-channel recordings was voltage dependent and demonstrated a high-conductance channel (245 +/- 2 pS) that was Ca2+ and CTX sensitive [IK(Ca)] and a low-conductance channel (109 +/- 2 pS) that was inhibited by 4-AP [IK(dr)] but was insensitive to low concentrations of TEA or to an increase in intracellular [Ca2+]. In isolated pulmonary arterial rings, TEA and 4-AP caused an additive increase in arterial tension. To our knowledge these data provide the first characterization of the IK in human pulmonary arterial smooth muscle cells and indicate that IK(Ca) and IK(dr) play an important role in maintaining pulmonary vascular tone. The data confirm previous observations in pulmonary smooth muscle cells of animal models.
Experimental model of human corpus cavernosum smooth muscle relaxation
Directory of Open Access Journals (Sweden)
Rommel P. Regadas
2010-08-01
Full Text Available PURPOSE: To describe a technique for en bloc harvesting of the corpus cavernosum, cavernous artery and urethra from transplant organ donors and contraction-relaxation experiments with corpus cavernosum smooth muscle. MATERIALS AND METHODS: The corpus cavernosum was dissected to the point of attachment with the crus penis. A 3 cm segment (corpus cavernosum and urethra was isolated and placed in ice-cold sterile transportation buffer. Under magnification, the cavernous artery was dissected. Thus, 2 cm fragments of cavernous artery and corpus cavernosum were obtained. Strips measuring 3 x 3 x 8 mm3 were then mounted vertically in an isolated organ bath device. Contractions were measured isometrically with a Narco-Biosystems force displacement transducer (model F-60, Narco-Biosystems, Houston, TX, USA and recorded on a 4-channel Narco-Biosystems desk model polygraph. RESULTS: Phenylephrine (1µM was used to induce tonic contractions in the corpus cavernosum (3 - 5 g tension and cavernous artery (0.5 - 1g tension until reaching a plateau. After precontraction, smooth muscle relaxants were used to produce relaxation-response curves (10-12M to 10-4 M. Sodium nitroprusside was used as a relaxation control. CONCLUSION: The harvesting technique and the smooth muscle contraction-relaxation model described in this study were shown to be useful instruments in the search for new drugs for the treatment of human erectile dysfunction.
Skeletal, cardiac, and smooth muscle failure in Duchenne muscular dystrophy.
Boland, B J; Silbert, P L; Groover, R V; Wollan, P C; Silverstein, M D
1996-01-01
The goals of this study were to describe the clinical course of skeletal, cardiac, and gastrointestinal muscle manifestations and trends in age at diagnosis and survival of Duchenne muscular dystrophy (DMD) patients. A retrospective cohort of 33 male patients with DMD, born between 1953 and 1983 and followed at the Mayo Clinic during their second decade of life, was studied. The mean age at DMD diagnosis was 4.6 years. Skeletal muscle weakness present in all patients at diagnosis progressed to wheelchair dependency in 32 patients (97%) by the age of 13 years (median age 10 years). Cardiac muscle failure developed in 5 patients (15%) (median age 21.5 years). Smooth muscle manifestations related to the digestive and urinary tracts occurred in 7 (21%) and 2 (6%) patients (median age 15 years), respectively. The gastrointestinal dilatations were primary in 2 patients or secondary to surgery or acute respiratory illness in 5 patients. By the end of the study period, 17 deaths had occurred (median age 17 years). Over time, there was a decrease in the time to DMD diagnosis (P = .05) but no significant change in survival (P = .44). Cardiac and smooth muscle manifestations occur late in the course of DMD. Clinical gastrointestinal symptoms related to smooth muscle function most often were secondary to surgery or a respiratory illness. In recent years, the diagnosis of DMD has been made at a younger age, but survival has not changed.
Lysyl Oxidase Propeptide Inhibits Smooth Muscle Cell Signaling and Proliferation
Hurtado, Paola A.; Vora, Siddharth; Sume, Siddika Selva; Yang, Dan; St. Hilaire, Cynthia; Guo, Ying; Palamakumbura, Amitha H.; Schreiber, Barbara M.; Ravid, Katya; Trackman, Philip C.
2008-01-01
Lysyl oxidase is required for the normal biosynthesis and maturation of collagen and elastin. It is expressed by vascular smooth muscle cells, and its increased expression has been previously found in atherosclerosis and in models of balloon angioplasty. The lysyl oxidase propeptide (LOX-PP) has more recently been found to have biological activity as a tumor suppressor, and it inhibits Erk1/2 Map kinase activation. We reasoned that LOX-PP may have functions in normal non-transformed cells. We, therefore, investigated its effects on smooth muscle cells, focusing on important biological processes mediated by Erk1/2-dependent signaling pathways including proliferation and matrix metalloproteinase-9 (MMP-9) expression. In addition, we investigated whether evidence for accumulation of LOX-PP could be found in vivo in a femoral artery injury model. Recombinant LOX-PP was expressed and purified, and was found to inhibit primary rat aorta smooth muscle cell proliferation and DNA synthesis by more than 50%. TNF-α-stimulated MMP-9 expression and Erk1/2 activation were both significantly inhibited by LOX-PP. Immunohistochemistry studies carried out with affinity purified anti-LOX-PP antibody showed that LOX-PP epitopes were expressed at elevated levels in vascular lesions of injured arteries. These novel data suggest that LOX-PP may provide a feedback control mechanism that serves to inhibit properties associated with the development of vascular pathology. PMID:18060869
Thapsigargin induces apoptosis in cultured human aortic smooth muscle cells.
Peiró, C; Vallejo, S; Cercas, E; Llergo, J L; Lafuente, N; Matesanz, N; Rodríguez-Mañas, L; Sánchez-Ferrer, C F
2000-11-01
Vascular remodeling is a key feature of many pathologic states, including atherosclerosis, or hypertension. Vascular smooth muscle cells participate in determining the vessel structure by several mechanisms such as cell migration, cell growth, or cell death (necrosis or apoptosis). Here we report that thapsigargin, an inhibitor of endoplasmic reticulum Ca2+ -adenosine triphosphatase (ATPase), is able to induce apoptosis in human vascular smooth muscle cells (HVSMCs). Apoptosis was assessed by three different methods: differential chromatin binding dye staining. cytoplasmic histone-associated DNA fragments detection by enzyme-linked immunosorbent assay (ELISA) and terminal deoxyribonucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL). When HVSMCs were treated for 1 h with thapsigargin (100 nM-10 microM), there was a concentration-dependent increase in both parameters 24 h after the thapsigargin pulse. When a time-course experiment was performed, both parameters were significantly enhanced from 3 to 6 h after the exposure to thapsigargin. We conclude that thapsigargin promotes apoptosis in HVSMCs, providing a useful tool for the study of programmed cell death in human vascular smooth muscle.
Experimental model of human corpus cavernosum smooth muscle relaxation.
Regadas, Rommel P; Moraes, Maria E A; Mesquita, Francisco J C; Cerqueira, Joao B G; Gonzaga-Silva, Lucio F
2010-01-01
To describe a technique for en bloc harvesting of the corpus cavernosum, cavernous artery and urethra from transplant organ donors and contraction-relaxation experiments with corpus cavernosum smooth muscle. The corpus cavernosum was dissected to the point of attachment with the crus penis. A 3 cm segment (corpus cavernosum and urethra) was isolated and placed in ice-cold sterile transportation buffer. Under magnification, the cavernous artery was dissected. Thus, 2 cm fragments of cavernous artery and corpus cavernosum were obtained. Strips measuring 3 x 3 x 8 mm(3) were then mounted vertically in an isolated organ bath device. Contractions were measured isometrically with a Narco-Biosystems force displacement transducer (model F-60, Narco-Biosystems, Houston, TX, USA) and recorded on a 4-channel Narco-Biosystems desk model polygraph. Phenylephrine (1 microM) was used to induce tonic contractions in the corpus cavernosum (3-5 g tension) and cavernous artery (0.5-1 g tension) until reaching a plateau. After precontraction, smooth muscle relaxants were used to produce relaxation-response curves (10(-12) M to 10(-4) M). Sodium nitroprusside was used as a relaxation control. The harvesting technique and the smooth muscle contraction-relaxation model described in this study were shown to be useful instruments in the search for new drugs for the treatment of human erectile dysfunction.
Electromyogram amplitude estimation with adaptive smoothing window length.
Clancy, E A
1999-06-01
Typical electromyogram (EMG) amplitude estimators use a fixed window length for smoothing the amplitude estimate. When the EMG amplitude is dynamic, previous research suggests that varying the smoothing length as a function of time may improve amplitude estimation. This paper develops optimal time-varying selection of the smoothing window length using a stochastic model of the EMG signal. Optimal selection is a function of the EMG amplitude and its derivatives. Simulation studies, in which EMG amplitude was changed randomly, found that the "best" adaptive filter performed as well as the "best" fixed-length filter. Experimental studies found the advantages of the adaptive processor to be situation dependent. Subjects used real-time EMG amplitude estimates to track a randomly-moving target. Perhaps due to task difficulty, no differences in adaptive versus fixed-length processors were observed when the target speed was fast. When the target speed was slow, the experimental results were consistent with the simulation predictions. When the target moved between two constant levels, the adaptive processor responded rapidly to the target level transitions and had low variance while the target dwelled on a level.
Stoppage in Autism Spectrum Disorders
DEFF Research Database (Denmark)
Grønborg, Therese Koops; Hansen, Stefan Nygaard; Nielsen, Svend V
2015-01-01
of bias in sibling recurrence risk estimation. This study investigated whether stoppage occurs in Danish families with a firstborn child diagnosed with autism spectrum disorders, and if stoppage was differential. We found that stoppage occurs moderately in Danish families affected by autism spectrum...... disorders, and that stoppage is differential. However, differential stoppage is a minor source of estimation bias in Danish sibling recurrence risk studies of autism spectrum disorders....
Rotational spectrum of tryptophan
Energy Technology Data Exchange (ETDEWEB)
Sanz, M. Eugenia, E-mail: maria.sanz@kcl.ac.uk; Cabezas, Carlos, E-mail: ccabezas@qf.uva.es; Mata, Santiago, E-mail: santiago.mata@uva.es; Alonso, Josè L., E-mail: jlalonso@qf.uva.es [Grupo de Espectroscopia Molecular (GEM), Edificio Quifima, Laboratorios de Espectroscopia y Bioespectroscopia, Unidad Asociada CSIC, Parque Científico Uva, Universidad de Valladolid, 47011 Valladolid (Spain)
2014-05-28
The rotational spectrum of the natural amino acid tryptophan has been observed for the first time using a combination of laser ablation, molecular beams, and Fourier transform microwave spectroscopy. Independent analysis of the rotational spectra of individual conformers has conducted to a definitive identification of two different conformers of tryptophan, with one of the observed conformers never reported before. The analysis of the {sup 14}N nuclear quadrupole coupling constants is of particular significance since it allows discrimination between structures, thus providing structural information on the orientation of the amino group. Both observed conformers are stabilized by an O–H···N hydrogen bond in the side chain and a N–H···π interaction forming a chain that reinforce the strength of hydrogen bonds through cooperative effects.
Electromagnetic spectrum management system
Seastrand, Douglas R.
2017-01-31
A system for transmitting a wireless countermeasure signal to disrupt third party communications is disclosed that include an antenna configured to receive wireless signals and transmit wireless counter measure signals such that the wireless countermeasure signals are responsive to the received wireless signals. A receiver processes the received wireless signals to create processed received signal data while a spectrum control module subtracts known source signal data from the processed received signal data to generate unknown source signal data. The unknown source signal data is based on unknown wireless signals, such as enemy signals. A transmitter is configured to process the unknown source signal data to create countermeasure signals and transmit a wireless countermeasure signal over the first antenna or a second antenna to thereby interfere with the unknown wireless signals.
Directory of Open Access Journals (Sweden)
Rebecca E. Rosenberg
2011-01-01
Full Text Available We used a national online registry to examine variation in cumulative prevalence of community diagnosis of psychiatric comorbidity in 4343 children with autism spectrum disorders (ASD. Adjusted multivariate logistic regression models compared influence of individual, family, and geographic factors on cumulative prevalence of parent-reported anxiety disorder, depression, bipolar disorder, and attention deficit/hyperactivity disorder or attention deficit disorder. Adjusted odds of community-assigned lifetime psychiatric comorbidity were significantly higher with each additional year of life, with increasing autism severity, and with Asperger syndrome and pervasive developmental disorder—not otherwise specified compared with autistic disorder. Overall, in this largest study of parent-reported community diagnoses of psychiatric comorbidity, gender, autistic regression, autism severity, and type of ASD all emerged as significant factors correlating with cumulative prevalence. These findings could suggest both underlying trends in actual comorbidity as well as variation in community interpretation and application of comorbid diagnoses in ASD.
Electromagnetic spectrum management system
Energy Technology Data Exchange (ETDEWEB)
Seastrand, Douglas R.
2017-10-17
A system for transmitting a wireless countermeasure signal to disrupt third party communications is disclosed that include an antenna configured to receive wireless signals and transmit wireless counter measure signals such that the wireless countermeasure signals are responsive to the received wireless signals. A receiver processes the received wireless signals to create processed received signal data while a spectrum control module subtracts known source signal data from the processed received signal data to generate unknown source signal data. The unknown source signal data is based on unknown wireless signals, such as enemy signals. A transmitter is configured to process the unknown source signal data to create countermeasure signals and transmit a wireless countermeasure signal over the first antenna or a second antenna to thereby interfere with the unknown wireless signals.
[Uterine smooth muscle tumors--determination of clinical behavior and classification].
Gincheva, D; Nikolova, M; Gorchev, G; Tomov, S
2014-01-01
The establishment of the clinical behavior of uterine smooth muscle tumors /USMT/ is an essential stage of modern diagnostics. There are significant differences in the criteria determining the malignant potential of smooth muscle gynecological tumors. Generally USMT generating diagnostic problems are classified into: clinically benign tumors; clinically malignant tumors with benign morphological features; smooth muscle tumors of uncertain malignant potential (SMTUMP) and lesions whose smooth muscle differentiation is not obvious. The knowledge in this area is essential for an adequate therapeutic approach.
Chang, Julia Yu Fong; Kessler, Harvey P.
2008-01-01
Myofibromas are well described in the head and neck region, but differentiating them from smooth muscle lesions is still difficult using smooth muscle immunohistochemical stains. This study evaluated the usefulness of the Masson trichrome stain in differentiating myofibromas from smooth muscle lesions in the head and neck region. Methods: Samples of 11 oral myofibromas, two leiomyomas, one angioleiomyoma, and one smooth muscle hamartoma were retrieved from our archives. Immunohistochemistr...
Stein, David B.; Guy, Robert D.; Thomases, Becca
2016-01-01
The Immersed Boundary method is a simple, efficient, and robust numerical scheme for solving PDE in general domains, yet it only achieves first-order spatial accuracy near embedded boundaries. In this paper, we introduce a new high-order numerical method which we call the Immersed Boundary Smooth Extension (IBSE) method. The IBSE method achieves high-order accuracy by smoothly extending the unknown solution of the PDE from a given smooth domain to a larger computational domain, enabling the use of simple Cartesian-grid discretizations (e.g. Fourier spectral methods). The method preserves much of the flexibility and robustness of the original IB method. In particular, it requires minimal geometric information to describe the boundary and relies only on convolution with regularized delta-functions to communicate information between the computational grid and the boundary. We present a fast algorithm for solving elliptic equations, which forms the basis for simple, high-order implicit-time methods for parabolic PDE and implicit-explicit methods for related nonlinear PDE. We apply the IBSE method to solve the Poisson, heat, Burgers', and Fitzhugh-Nagumo equations, and demonstrate fourth-order pointwise convergence for Dirichlet problems and third-order pointwise convergence for Neumann problems.
Pipes, G. C. Teg; Sinha, Sanjay; Qi, Xiaoxia; Zhu, Chun-Hong; Gallardo, Teresa D.; Shelton, John; Creemers, Esther E.; Sutherland, Lillian; Richardson, James A.; Garry, Daniel J.; Wright, Woodring E.; Owens, Gary K.; Olson, Eric N.
2005-01-01
The Serum Response Factor (SRF) coactivator myocardin stimulates the transcription of multiple muscle genes during cardiac and smooth muscle development. Mouse embryos lacking myocardin die during the earliest stages of smooth muscle development and fail to express multiple smooth muscle marker
Woudt, Edwin; de Boer, Pieter-Tjerk; van Ommeren, Jan C.W.
2007-01-01
Previous work on state-dependent adaptive importance sampling techniques for the simulation of rare events in Markovian queueing models used either no smoothing or a parametric smoothing technique, which was known to be non-optimal. In this paper, we introduce the use of kernel smoothing in this
Su, Gang; Sun, Guangli; Liu, Hai; Shu, Liliang; Zhang, Jingchao; Guo, Longhui; Huang, Chen; Xu, Jing
2015-12-29
BACKGROUND Niacin is a broad-spectrum lipid-regulating drug used for the clinical therapy of atherosclerosis; however, the mechanisms by which niacin ameliorates atherosclerosis are not clear. MATERIAL AND METHODS The effect of niacin on atherosclerosis was assessed by detection of atherosclerotic lesion area. Adhesion molecules in arterial endothelial cells were determined by using qRT-PCR and Western blot analysis. The levels of serum inflammatory cytokines in ApoE-/- mice were detected by using ELISA. We detected the expression levels of phosphorylated nuclear factors-kB (NF-κB) p65 in aortic endothelial cells of mice using Western blot analysis. Furthermore, we investigated the anti-inflammation effect and endothelium-protecting function of niacin and their regulatory mechanisms in vitro. RESULTS Niacin inhibited the progress of atherosclerosis and decreased the levels of serum inflammatory cytokines and adhesion molecules in ApoE-/- mice. Niacin suppressed the activity of NF-κB and apoptosis of vascular smooth muscle cells (VSMCs). Furthermore, niacin induced phosphorylated focal adhesion kinase (FAK) and FAK inhibitor PF-573228 reduced the level of Bcl-2 and elevated the level of cleaved caspase-3 in VSMCs. CONCLUSIONS Niacin inhibits vascular inflammation and apoptosis of VSMCs via inhibiting the NF-κB signaling and the FAK signaling pathway, respectively, thus protecting ApoE-/- mice against atherosclerosis.
Dynamic Spectrum Sharing among Femtocells
DEFF Research Database (Denmark)
Da Costa, Gustavo Wagner Oliveira
2012-01-01
The ever-growing demand for mobile broadband is leading to an imminent spectrum scarcity. In order to cope with such situation dynamic spectrum sharing and the widespread deployment of small cells (femtocells) are promising solutions. Delivering such a view is not short of challenges. Massive...
Autism Spectrum Disorder - Multiple Languages
... Supplements Videos & Tools You Are Here: Home → Multiple Languages → All Health Topics → Autism Spectrum Disorder URL of this page: https://medlineplus. ... V W XYZ List of All Topics All Autism Spectrum Disorder - Multiple Languages To use the sharing features on this page, ...
Indecomposable polynomials and their spectrum
Bodin, Arnaud; Debes, Pierre; Najib, Salah
We address some questions concerning indecomposable polynomials and their spectrum. How does the spectrum behave via reduction or specialization, or via a more general ring morphism? Are the indecomposability properties equivalent over a field and over its algebraic closure? How many polynomials are decomposable over a finite field?
Smoothing of respiratory motion traces for motion-compensated radiotherapy.
Ernst, Floris; Schlaefer, Alexander; Schweikard, Achim
2010-01-01
The CyberKnife system has been used successfully for several years to radiosurgically treat tumors without the need for stereotactic fixation or sedation of the patient. It has been shown that tumor motion in the lung, liver, and pancreas can be tracked with acceptable accuracy and repeatability. However, highly precise targeting for tumors in the lower abdomen, especially for tumors which exhibit strong motion, remains problematic. Reasons for this are manifold, like the slow tracking system operating at 26.5 Hz, and using the signal from the tracking camera "as is." Since the motion recorded with the camera is used to compensate for system latency by prediction and the predicted signal is subsequently used to infer the tumor position from a correlation model based on x-ray imaging of gold fiducials around the tumor, camera noise directly influences the targeting accuracy. The goal of this work is to establish the suitability of a new smoothing method for respiratory motion traces used in motion-compensated radiotherapy. The authors endeavor to show that better prediction--With a lower rms error of the predicted signal--and/or smoother prediction is possible using this method. The authors evaluated six commercially available tracking systems (NDI Aurora, PolarisClassic, Polaris Vicra, MicronTracker2 H40, FP5000, and accuTrack compact). The authors first tracked markers both stationary and while in motion to establish the systems' noise characteristics. Then the authors applied a smoothing method based on the a trous wavelet decomposition to reduce the devices' noise level. Additionally, the smoothed signal of the moving target and a motion trace from actual human respiratory motion were subjected to prediction using the MULIN and the nLMS2 algorithms. The authors established that the noise distribution for a static target is Gaussian and that when the probe is moved such as to mimic human respiration, it remains Gaussian with the exception of the FP5000 and the
Rotational Spectrum of Saccharine
Alonso, Elena R.; Mata, Santiago; Alonso, José L.
2017-06-01
A significant step forward in the structure-activity relationships of sweeteners was the assignment of the AH-B moiety in sweeteners by Shallenberger and Acree. They proposed that all sweeteners contain an AH-B moiety, known as glucophore, in which A and B are electronegative atoms separated by a distance between 2.5 to 4 Å. H is a hydrogen atom attached to one of the electronegative atom by a covalent bond. For saccharine, one of the oldest artificial sweeteners widely used in food and drinks, two possible B moieties exist ,the carbonyl oxygen atom and the sulfoxide oxygen atom although there is a consensus of opinion among scientists over the assignment of AH-B moieties to HN-SO. In the present work, the solid of saccharine (m.p. 220°C) has been vaporized by laser ablation (LA) and its rotational spectrum has been analyzed by broadband CP-FTMW and narrowband MB-FTMW Fourier transform microwave techniques. The detailed structural information extracted from the rotational constants and ^{14}N nuclear quadrupole coupling constants provided enough information to ascribe the glucophore's AH and B sites of saccharine. R. S. Shallenberger, T. E. Acree. Nature 216, 480-482 Nov 1967. R. S. Shallenberger. Taste Chemistry; Blackie Academic & Professional, London, (1993).
Fetal Alcohol Spectrum Disorders.
Williams, Janet F; Smith, Vincent C
2015-11-01
Prenatal exposure to alcohol can damage the developing fetus and is the leading preventable cause of birth defects and intellectual and neurodevelopmental disabilities. In 1973, fetal alcohol syndrome was first described as a specific cluster of birth defects resulting from alcohol exposure in utero. Subsequently, research unequivocally revealed that prenatal alcohol exposure causes a broad range of adverse developmental effects. Fetal alcohol spectrum disorder (FASD) is the general term that encompasses the range of adverse effects associated with prenatal alcohol exposure. The diagnostic criteria for fetal alcohol syndrome are specific, and comprehensive efforts are ongoing to establish definitive criteria for diagnosing the other FASDs. A large and growing body of research has led to evidence-based FASD education of professionals and the public, broader prevention initiatives, and recommended treatment approaches based on the following premises:▪ Alcohol-related birth defects and developmental disabilities are completely preventable when pregnant women abstain from alcohol use.▪ Neurocognitive and behavioral problems resulting from prenatal alcohol exposure are lifelong.▪ Early recognition, diagnosis, and therapy for any condition along the FASD continuum can result in improved outcomes.▪ During pregnancy:◦no amount of alcohol intake should be considered safe;◦there is no safe trimester to drink alcohol;◦all forms of alcohol, such as beer, wine, and liquor, pose similar risk; and◦binge drinking poses dose-related risk to the developing fetus. Copyright © 2015 by the American Academy of Pediatrics.
PINS Spectrum Identification Guide
Energy Technology Data Exchange (ETDEWEB)
A.J. Caffrey
2012-03-01
The Portable Isotopic Neutron Spectroscopy—PINS, for short—system identifies the chemicals inside munitions and containers without opening them, a decided safety advantage if the fill chemical is a hazardous substance like a chemical warfare agent or an explosive. The PINS Spectrum Identification Guide is intended as a reference for technical professionals responsible for the interpretation of PINS gamma-ray spectra. The guide is divided into two parts. The three chapters that constitute Part I cover the science and technology of PINS. Neutron activation analysis is the focus of Chapter 1. Chapter 2 explores PINS hardware, software, and related operational issues. Gamma-ray spectral analysis basics are introduced in Chapter 3. The six chapters of Part II cover the identification of PINS spectra in detail. Like the PINS decision tree logic, these chapters are organized by chemical element: phosphorus-based chemicals, chlorine-based chemicals, etc. These descriptions of hazardous, toxic, and/or explosive chemicals conclude with a chapter on the identification of the inert chemicals, e.g. sand, used to fill practice munitions.
Directory of Open Access Journals (Sweden)
Alexander Kramida
2017-02-01
Full Text Available New wavelength measurements in the vacuum ultraviolet (VUV, ultraviolet and visible spectral regions have been combined with available literature data to refine and extend the description of the spectrum of singly ionized copper (Cu II. In the VUV region, we measured 401 lines using a concave grating spectrograph and photographic plates. In the UV and visible regions, we measured 276 lines using a Fourier-transform spectrometer. These new measurements were combined with previously unpublished data from the thesis of Ross, with accurate VUV grating measurements of Kaufman and Ward, and with less accurate older measurements of Shenstone to construct a comprehensive list of ≈2440 observed lines, from which we derived a revised set of 379 optimized energy levels, complemented with 89 additional levels obtained using series formulas. Among the 379 experimental levels, 29 are new. Intensities of all lines observed in different experiments have been reduced to the same uniform scale by using newly calculated transition probabilities (A-values. We combined our calculations with published measured and calculated A-values to provide a set of 555 critically evaluated transition probabilities with estimated uncertainties, 162 of which are less than 20%.
Comparison of RF spectrum prediction methods for dynamic spectrum access
Kovarskiy, Jacob A.; Martone, Anthony F.; Gallagher, Kyle A.; Sherbondy, Kelly D.; Narayanan, Ram M.
2017-05-01
Dynamic spectrum access (DSA) refers to the adaptive utilization of today's busy electromagnetic spectrum. Cognitive radio/radar technologies require DSA to intelligently transmit and receive information in changing environments. Predicting radio frequency (RF) activity reduces sensing time and energy consumption for identifying usable spectrum. Typical spectrum prediction methods involve modeling spectral statistics with Hidden Markov Models (HMM) or various neural network structures. HMMs describe the time-varying state probabilities of Markov processes as a dynamic Bayesian network. Neural Networks model biological brain neuron connections to perform a wide range of complex and often non-linear computations. This work compares HMM, Multilayer Perceptron (MLP), and Recurrent Neural Network (RNN) algorithms and their ability to perform RF channel state prediction. Monte Carlo simulations on both measured and simulated spectrum data evaluate the performance of these algorithms. Generalizing spectrum occupancy as an alternating renewal process allows Poisson random variables to generate simulated data while energy detection determines the occupancy state of measured RF spectrum data for testing. The results suggest that neural networks achieve better prediction accuracy and prove more adaptable to changing spectral statistics than HMMs given sufficient training data.
Smooth extrapolation of unknown anatomy via statistical shape models
Grupp, R. B.; Chiang, H.; Otake, Y.; Murphy, R. J.; Gordon, C. R.; Armand, M.; Taylor, R. H.
2015-03-01
Several methods to perform extrapolation of unknown anatomy were evaluated. The primary application is to enhance surgical procedures that may use partial medical images or medical images of incomplete anatomy. Le Fort-based, face-jaw-teeth transplant is one such procedure. From CT data of 36 skulls and 21 mandibles separate Statistical Shape Models of the anatomical surfaces were created. Using the Statistical Shape Models, incomplete surfaces were projected to obtain complete surface estimates. The surface estimates exhibit non-zero error in regions where the true surface is known; it is desirable to keep the true surface and seamlessly merge the estimated unknown surface. Existing extrapolation techniques produce non-smooth transitions from the true surface to the estimated surface, resulting in additional error and a less aesthetically pleasing result. The three extrapolation techniques evaluated were: copying and pasting of the surface estimate (non-smooth baseline), a feathering between the patient surface and surface estimate, and an estimate generated via a Thin Plate Spline trained from displacements between the surface estimate and corresponding vertices of the known patient surface. Feathering and Thin Plate Spline approaches both yielded smooth transitions. However, feathering corrupted known vertex values. Leave-one-out analyses were conducted, with 5% to 50% of known anatomy removed from the left-out patient and estimated via the proposed approaches. The Thin Plate Spline approach yielded smaller errors than the other two approaches, with an average vertex error improvement of 1.46 mm and 1.38 mm for the skull and mandible respectively, over the baseline approach.
Neuronal nitric oxide inhibits intestinal smooth muscle growth.
Pelletier, Anne-Marie; Venkataramana, Shriram; Miller, Kurtis G; Bennett, Brian M; Nair, Dileep G; Lourenssen, Sandra; Blennerhassett, Michael G
2010-06-01
Hyperplasia of smooth muscle contributes to the thickening of the intestinal wall that is characteristic of inflammation, but the mechanisms of growth control are unknown. Nitric oxide (NO) from enteric neurons expressing neuronal NO synthase (nNOS) might normally inhibit intestinal smooth muscle cell (ISMC) growth, and this was tested in vitro. In ISMC from the circular smooth muscle of the adult rat colon, chemical NO donors inhibited [(3)H]thymidine uptake in response to FCS, reducing this to baseline without toxicity. This effect was inhibited by the guanylyl cyclase inhibitor ODQ and potentiated by the phosphodiesterase-5 inhibitor zaprinast. Inhibition was mimicked by 8-bromo (8-Br)-cGMP, and ELISA measurements showed increased levels of cGMP but not cAMP in response to sodium nitroprusside. However, 8-Br-cAMP and cilostamide also showed inhibitory actions, suggesting an additional role for cAMP. Via a coculture model of ISMC and myenteric neurons, immunocytochemistry and image analysis showed that innervation reduced bromodeoxyuridine uptake by ISMC. Specific blockers of nNOS (7-NI, NAAN) significantly increased [(3)H]thymidine uptake in response to a standard stimulus, showing that nNOS activity normally inhibits ISMC growth. In vivo, nNOS axon number was reduced threefold by day 1 of trinitrobenzene sulfonic acid-induced rat colitis, preceding the hyperplasia of ISMC described earlier in this model. We conclude that NO can inhibit ISMC growth primarily via a cGMP-dependent mechanism. Functional evidence that NO derived from nNOS causes inhibition of ISMC growth in vitro predicts that the loss of nNOS expression in colitis contributes to ISMC hyperplasia in vivo.
Effects of slope smoothing in river channel modeling
Kim, Kyungmin; Liu, Frank; Hodges, Ben R.
2017-04-01
In extending dynamic river modeling with the 1D Saint-Venant equations from a single reach to a large watershed there are critical questions as to how much bathymetric knowledge is necessary and how it should be represented parsimoniously. The ideal model will include the detail necessary to provide realism, but not include extraneous detail that should not exert a control on a 1D (cross-section averaged) solution. In a Saint-Venant model, the overall complexity of the river channel morphometry is typically abstracted into metrics for the channel slope, cross-sectional area, hydraulic radius, and roughness. In stream segments where cross-section surveys are closely spaced, it is not uncommon to have sharp changes in slope or even negative values (where a positive slope is the downstream direction). However, solving river flow with the Saint-Venant equations requires a degree of smoothness in the equation parameters or the equation set with the directly measured channel slopes may not be Lipschitz continuous. The results of non-smoothness are typically extended computational time to converge solutions (or complete failure to converge) and/or numerical instabilities under transient conditions. We have investigated using cubic splines to smooth the bottom slope and ensure always positive reference slopes within a 1D model. This method has been implemented in the Simulation Program for River Networks (SPRNT) and is compared to the standard HEC-RAS river solver. It is shown that the reformulation of the reference slope is both in keeping with the underlying derivation of the Saint-Venant equations and provides practical numerical stability without altering the realism of the simulation. This research was supported in part by the National Science Foundation under grant number CCF-1331610.
Bessel smoothing filter for spectral-element mesh
Trinh, P. T.; Brossier, R.; Métivier, L.; Virieux, J.; Wellington, P.
2017-06-01
Smoothing filters are extremely important tools in seismic imaging and inversion, such as for traveltime tomography, migration and waveform inversion. For efficiency, and as they can be used a number of times during inversion, it is important that these filters can easily incorporate prior information on the geological structure of the investigated medium, through variable coherent lengths and orientation. In this study, we promote the use of the Bessel filter to achieve these purposes. Instead of considering the direct application of the filter, we demonstrate that we can rely on the equation associated with its inverse filter, which amounts to the solution of an elliptic partial differential equation. This enhances the efficiency of the filter application, and also its flexibility. We apply this strategy within a spectral-element-based elastic full waveform inversion framework. Taking advantage of this formulation, we apply the Bessel filter by solving the associated partial differential equation directly on the spectral-element mesh through the standard weak formulation. This avoids cumbersome projection operators between the spectral-element mesh and a regular Cartesian grid, or expensive explicit windowed convolution on the finite-element mesh, which is often used for applying smoothing operators. The associated linear system is solved efficiently through a parallel conjugate gradient algorithm, in which the matrix vector product is factorized and highly optimized with vectorized computation. Significant scaling behaviour is obtained when comparing this strategy with the explicit convolution method. The theoretical numerical complexity of this approach increases linearly with the coherent length, whereas a sublinear relationship is observed practically. Numerical illustrations are provided here for schematic examples, and for a more realistic elastic full waveform inversion gradient smoothing on the SEAM II benchmark model. These examples illustrate well the
Experimental comparison of PV-smoothing controllers using distributed generators
Energy Technology Data Exchange (ETDEWEB)
Johnson, Jay Dean; Ellis, Abraham; Denda, Atsushi; Morino, Kimio; Hawkins, John N.; Arellano, Brian; Shinji, Takao; Ogata, Takao; Tadokoro, Masayuki
2014-02-01
The power output variability of photovoltaic systems can affect local electrical grids in locations with high renewable energy penetrations or weak distribution or transmission systems. In those rare cases, quick controllable generators (e.g., energy storage systems) or loads can counteract the destabilizing effects by compensating for the power fluctuations. Previously, control algorithms for coordinated and uncoordinated operation of a small natural gas engine-generator (genset) and a battery for smoothing PV plant output were optimized using MATLAB/Simulink simulations. The simulations demonstrated that a traditional generation resource such as a natural gas genset in combination with a battery would smooth the photovoltaic output while using a smaller battery state of charge (SOC) range and extending the life of the battery. This paper reports on the experimental implementation of the coordinated and uncoordinated controllers to verify the simulations and determine the differences in the controllers. The experiments were performed with the PNM PV and energy storage Prosperity site and a gas engine-generator located at the Aperture Center at Mesa Del Sol in Albuquerque, New Mexico. Two field demonstrations were performed to compare the different PV smoothing control algorithms: (1) implementing the coordinated and uncoordinated controls while switching off a subsection of the PV array at precise times on successive clear days, and (2) comparing the results of the battery and genset outputs for the coordinated control on a high variability day with simulations of the coordinated and uncoordinated controls. It was found that for certain PV power profiles the SOC range of the battery may be larger with the coordinated control, but the total amp-hours through the battery-which approximates battery wear-will always be smaller with the coordinated control.
Interaction of Vascular Smooth Muscle Cells Under Low Shear Stress
Seidel, Charles L.
1998-01-01
The blood vessel wall consists of three cellular layers, an outer adventitial, a middle medial and an inner intimal layer. When the blood vessel forms in the embryo it begins as a tube composed of a single cell type called endothelial cells. Over time, other cells are recruited from the surrounding tissue to form additional layers on the outer surface of the endothelial tube. The cells that are recruited are called mesenchymal cells. Mesenchymal cells are responsible for the production of connective tissue that holds the blood vessel together and for developing into vascular smooth muscle cells that are responsible for regulating the diameter of the vessel (1) and therefore, blood flow. In a fully developed blood vessel, the endothelial cells make- up the majority of cells in the intimal layer while the mesenchymal cells make-up the majority of cells in the medial and adventitial layers. Within the medial layer of a mature vessel, cells are organized into multiple circular layers of alternating bands of connective tissue and cells. The cell layer is composed of a mixture of mesenchymal cells that have not developed into smooth muscle cells and fully developed smooth muscle cells (2). The assembly and organization of complex tissues is directed in part by a signaling system composed of proteins on the cell surface called adhesion molecules. Adhesion molecules enable cells to recognize each other as well as the composition of the connective tissue in which they reside (3). It was hypothesized that the different cell types that compose the vascular wall possess different adhesion molecules that enable them to recognize each other and through this recognition system, form the complex layered organization of the vascular wall. In other words, the layered organization is an intrinsic property of the cells. If this hypothesis is correct then the different cells that make up the vessel wall, when mixed together, should organize themselves into a layered structure
Modeling electrokinetic flows by consistent implicit incompressible smoothed particle hydrodynamics
Pan, Wenxiao; Kim, Kyungjoo; Perego, Mauro; Tartakovsky, Alexandre M.; Parks, Michael L.
2017-04-01
We present a consistent implicit incompressible smoothed particle hydrodynamics (I2SPH) discretization of Navier-Stokes, Poisson-Boltzmann, and advection-diffusion equations subject to Dirichlet or Robin boundary conditions. It is applied to model various two and three dimensional electrokinetic flows in simple or complex geometries. The accuracy and convergence of the consistent I2SPH are examined via comparison with analytical solutions, grid-based numerical solutions, or empirical models. The new method provides a framework to explore broader applications of SPH in microfluidics and complex fluids with charged objects, such as colloids and biomolecules, in arbitrary complex geometries.
Plasticity of cerebrovascular smooth muscle cells after subarachnoid hemorrhage
DEFF Research Database (Denmark)
Edvinsson, Lars; Larsen, Stine Schmidt; Maddahi, Aida
2014-01-01
Subarachnoid hemorrhage (SAH) is most often followed by a delayed phase of cerebral ischemia which is associated with high morbidity and mortality rates. The causes underlying this delayed phase are still unsettled, but are believed to include cerebral vasospasm, cortical spreading depression......, inflammatory reactions, and microthrombosis. Additionally, a large body of evidence indicates that vascular plasticity plays an important role in SAH pathophysiology, and this review aims to summarize our current knowledge on the phenotypic changes of vascular smooth muscle cells of the cerebral vasculature...
Brownian semi-stationary processes, turbulence and smooth processes
DEFF Research Database (Denmark)
Urbina, José Ulises Márquez
This thesis analysis the use of Brownian semi-stationary (BSS) processes to model the main statistical features present in turbulent time series, and some asymptotic properties of certain classes of smooth processes. Turbulence is a complex phenomena governed by the Navier-Stokes equations....... We also studied the distributional properties of the increments of BSS processes with the intent to better understand why the BSS processes seem to accurately reproduce the temporal turbulent dynamics. BSS processes in general are not semimartingales. However, there are conditions which make a BSS...
Modeling electrokinetic flows by consistent implicit incompressible smoothed particle hydrodynamics
Energy Technology Data Exchange (ETDEWEB)
Pan, Wenxiao; Kim, Kyungjoo; Perego, Mauro; Tartakovsky, Alexandre M.; Parks, Michael L.
2017-04-01
We present an efficient implicit incompressible smoothed particle hydrodynamics (I2SPH) discretization of Navier-Stokes, Poisson-Boltzmann, and advection-diffusion equations subject to Dirichlet or Robin boundary conditions. It is applied to model various two and three dimensional electrokinetic flows in simple or complex geometries. The I2SPH's accuracy and convergence are examined via comparison with analytical solutions, grid-based numerical solutions, or empirical models. The new method provides a framework to explore broader applications of SPH in microfluidics and complex fluids with charged objects, such as colloids and biomolecules, in arbitrary complex geometries.
A Smoothed Eclipse Model for Solar Electric Propulsion Trajectory Optimization
Aziz, Jonathan; Scheeres, Daniel; Parker, Jeffrey; Englander, Jacob
2017-01-01
Solar electric propulsion (SEP) is the dominant design option for employing low-thrust propulsion on a space mission. Spacecraft solar arrays power the SEP system but are subject to blackout periods during solar eclipse conditions. Discontinuity in power available to the spacecraft must be accounted for in trajectory optimization, but gradient-based methods require a differentiable power model. This work presents a power model that smooths the eclipse transition from total eclipse to total sunlight with a logistic function. Example trajectories are computed with differential dynamic programming, a second-order gradient-based method.
Smooth bridge between guided waves and spoof surface plasmon polaritons.
Liu, Liangliang; Li, Zhuo; Gu, Changqing; Xu, Bingzheng; Ning, Pingping; Chen, Chen; Yan, Jian; Niu, Zhenyi; Zhao, Yongjiu
2015-04-15
In this work, we build a smooth bridge between a coaxial waveguide and a plasmonic waveguide with subwavelength periodically cylindrical radial grooves, to realize high-efficiency mode conversion between conventional guided waves and spoof surface plasmon polaritons in broadband. This bridge consists of a flaring coaxial waveguide connected with a metal cylindrical wire corrugated with subwavelength gradient radial grooves. Experimental results of the transmission and reflection coefficients show excellent agreement with the numerical simulations. The proposed scheme can be extended readily to other bands and the bridge structure can find potential applications in the integration of conventional microwave or terahertz devices with plasmonic circuits.
A numerical optimization approach to generate smoothing spherical splines
Machado, L.; Monteiro, M. Teresa T.
2017-01-01
Approximating data in curved spaces is a common procedure that is extremely required by modern applications arising, for instance, in aerospace and robotics industries. Here, we are particularly interested in finding smoothing cubic splines that best fit given data in the Euclidean sphere. To achieve this aim, a least squares optimization problem based on the minimization of a certain cost functional is formulated. To solve the problem a numerical algorithm is implemented using several routines from MATLAB toolboxes. The proposed algorithm is shown to be easy to implement, very accurate and precise for spherical data chosen randomly.
Electric drive systems including smoothing capacitor cooling devices and systems
Dede, Ercan Mehmet; Zhou, Feng
2017-02-28
An electric drive system includes a smoothing capacitor including at least one terminal, a bus bar electrically coupled to the at least one terminal, a thermoelectric device including a first side and a second side positioned opposite the first side, where the first side is thermally coupled to at least one of the at least one terminal and the bus bar, and a cooling element thermally coupled to the second side of the thermoelectric device, where the cooling element dissipates heat from the thermoelectric device.
Violation of smooth observable macroscopic realism in a harmonic oscillator.
Leshem, Amir; Gat, Omri
2009-08-14
We study the emergence of macrorealism in a harmonic oscillator subject to consecutive measurements of a squeezed action. We demonstrate a breakdown of dynamical realism in a wide parameter range that is maximized in a scaling limit of extreme squeezing, where it is based on measurements of smooth observables, implying that macroscopic realism is not valid in the harmonic oscillator. We propose an indirect experimental test of these predictions with entangled photons by demonstrating that local realism in a composite system implies dynamical realism in a subsystem.
Smoothed Particle Hydrodynamics Method for Two-dimensional Stefan Problem
Tarwidi, Dede
2016-01-01
Smoothed particle hydrodynamics (SPH) is developed for modelling of melting and solidification. Enthalpy method is used to solve heat conduction equations which involved moving interface between phases. At first, we study the melting of floating ice in the water for two-dimensional system. The ice objects are assumed as solid particles floating in fluid particles. The fluid and solid motion are governed by Navier-Stokes equation and basic rigid dynamics equation, respectively. We also propose a strategy to separate solid particles due to melting and solidification. Numerical results are obtained and plotted for several initial conditions.
On the Complexity of Smooth Projective Toric Varieties
Hosten, S
1996-01-01
In this paper we answer a question posed by V.V. Batyrev. The question asked if there exists a complete regular fan with more than quadratically many primitive collections. We construct a smooth projective toric variety associated to a complete regular fan $\\Delta$ in R^d with $n$ generators where the number of primitive collections of $\\Delta$ is at least exponential in $n-d$. We also exhibit the connection between the number of primitive collections of $\\Delta$ and the facet complexity of the Gröbner fan of the associated integer program.
Dual conformal transformations of smooth holographic Wilson loops
Energy Technology Data Exchange (ETDEWEB)
Dekel, Amit [Nordita, KTH Royal Institute of Technology and Stockholm University, Roslagstullsbacken 23, SE-106 91 Stockholm (Sweden)
2017-01-19
We study dual conformal transformations of minimal area surfaces in AdS{sub 5}×S{sup 5} corresponding to holographic smooth Wilson loops and some other related observables. To act with dual conformal transformations we map the string solutions to the dual space by means of T-duality, then we apply a conformal transformation and finally T-dualize back to the original space. The transformation maps between string solutions with different boundary contours. The boundary contours of the minimal surfaces are not mapped back to the AdS boundary, and the regularized area of the surface changes.
Ferguson curve model and morphological smoothing of ruled surfaces
Popov, Antony T.
2001-11-01
This work studies the generation of a ruled surface from scattered data, which can be obtained by a shape- from - X procedure or can be an experimental output. The ruled surface is generated by the so- called Ferguson Curve Model. This model is an interpolation technique based on parametric cubic polynomials, and thus guaranteeing continuity of the curvature in each point of the initial set. We show how morphological operations - esp. openings and closings can be used to obtain good smoothness of the surface in practice. An application to robot motion planning is presented.
Measurements of drag and lift on smooth balls in flight
Cross, Rod; Lindsey, Crawford
2017-07-01
Measurements are presented on the drag and lift coefficients for three relatively smooth balls launched in air and tracked with two cameras separated horizontally by 6.4 m. The ball spin was varied in order to investigate whether the Magnus force would increase or decrease when the ball spin was increased. For one ball, the Magnus force increased. For another ball, the Magnus force decreased almost to zero after reaching a maximum. For the third ball, the Magnus force was negative at low ball spins and positive at high ball spins. For one of the balls, the ball spin increased with time as it travelled through the air.
On the vanishing rate of smooth CR functions
Directory of Open Access Journals (Sweden)
Giuseppe Della Sala
2014-01-01
Full Text Available Let be a lineally convex hypersurface of ℂⁿ of finite type, 0∈. Then there exist non-trivial smooth CR functions on that are flat at 0, i.e. whose Taylor expansion about 0 vanishes identically. Our aim is to characterize the rate at which flat CR functions can decrease without vanishing identically. As it turns out, non-trivial CR functions cannot decay arbitrarily fast, and a possible way of expressing the critical rate is by comparison with a suitable exponential of the modulus of a local peak function.
A Method for Low-Delay Pitch Tracking and Smoothing
Christensen, Mads Græsbøll
2012-01-01
In this paper, a new method for pitch tracking is presented. The method is comprised of two steps. In the first step, accurate pitch estimates are obtained on a sample-by-sample basis by updates of the signal statistics with an exponential forgetting factor and subse- quent numerical optimization. In the second step, a Kalman filter is used to smooth the estimates and separate the pitch into a slowly varying component and a rapidly varying component. The former represents the mean pitch while...
DEFF Research Database (Denmark)
Rumessen, Jüri Johannes; Thuneberg, Lars
1991-01-01
Anatomy, interstitial cells of Cajal, small intestine, gut motility, pacemaker cells, smooth muscle......Anatomy, interstitial cells of Cajal, small intestine, gut motility, pacemaker cells, smooth muscle...
Chang, Julia Yu Fong; Kessler, Harvey P
2008-10-01
Myofibromas are well described in the head and neck region, but differentiating them from smooth muscle lesions is still difficult using smooth muscle immunohistochemical stains. This study evaluated the usefulness of the Masson trichrome stain in differentiating myofibromas from smooth muscle lesions in the head and neck region. Samples of 11 oral myofibromas, two leiomyomas, one angioleiomyoma, and one smooth muscle hamartoma were retrieved from our archives. Immunohistochemistry and Masson trichrome stains were performed on tissue sections of these lesions. All 11 oral myofibromas, seven from male patients and four from female patients, were solitary myofibromas. The patients' mean age at diagnosis was 32.8 years. Oral myofibromas occurred most commonly on the gingiva (four cases) and in the mandible (three cases). With the Masson trichrome stain, the smooth muscle cell cytoplasm was stained red, while the collagenous fibrous tissue was stained blue. Myofibromas and smooth muscle lesions demonstrated different characteristic patterns with the Masson trichrome stain. Myofibromas were composed of a much more collagenous stroma intermixed with the spindle cells. Thick fibrous bundles with random, irregularly intersecting angles were prominent in myofibromas. Smooth muscle lesions showed only minimal delicate fibrous tissue surrounding the smooth muscle cells and in the septa between the smooth muscle masses. On low-power view, red masses of smooth muscle tumor surrounded by blue fibrous tissue were observed. The Masson trichrome stain can be a useful tool to differentiate myofibromas from smooth muscle lesions, but immunohistochemical methods to rule out other spindle cell lesions are still needed.
The Jacobian Consistency of a One-Parametric Class of Smoothing Functions for SOCCP
Directory of Open Access Journals (Sweden)
Xiaoni Chi
2013-01-01
Full Text Available Second-order cone (SOC complementarity functions and their smoothing functions have been much studied in the solution of second-order cone complementarity problems (SOCCP. In this paper, we study the directional derivative and B-subdifferential of the one-parametric class of SOC complementarity functions, propose its smoothing function, and derive the computable formula for the Jacobian of the smoothing function. Based on these results, we prove the Jacobian consistency of the one-parametric class of smoothing functions, which will play an important role for achieving the rapid convergence of smoothing methods. Moreover, we estimate the distance between the subgradient of the one-parametric class of the SOC complementarity functions and the gradient of its smoothing function, which will help to adjust a parameter appropriately in smoothing methods.
Directory of Open Access Journals (Sweden)
Nguyen Manh Hung
2008-03-01
Full Text Available In this paper, we consider the second initial boundary value problem for strongly general Schrodinger systems in both the finite and the infinite cylinders $Q_T, 0
Directional bilateral filters for smoothing fluorescence microscopy images
Venkatesh, Manasij; Mohan, Kavya; Seelamantula, Chandra Sekhar
2015-08-01
Images obtained through fluorescence microscopy at low numerical aperture (NA) are noisy and have poor resolution. Images of specimens such as F-actin filaments obtained using confocal or widefield fluorescence microscopes contain directional information and it is important that an image smoothing or filtering technique preserve the directionality. F-actin filaments are widely studied in pathology because the abnormalities in actin dynamics play a key role in diagnosis of cancer, cardiac diseases, vascular diseases, myofibrillar myopathies, neurological disorders, etc. We develop the directional bilateral filter as a means of filtering out the noise in the image without significantly altering the directionality of the F-actin filaments. The bilateral filter is anisotropic to start with, but we add an additional degree of anisotropy by employing an oriented domain kernel for smoothing. The orientation is locally adapted using a structure tensor and the parameters of the bilateral filter are optimized for within the framework of statistical risk minimization. We show that the directional bilateral filter has better denoising performance than the traditional Gaussian bilateral filter and other denoising techniques such as SURE-LET, non-local means, and guided image filtering at various noise levels in terms of peak signal-to-noise ratio (PSNR). We also show quantitative improvements in low NA images of F-actin filaments.
Smoothing-Based Relative Navigation and Coded Aperture Imaging
Saenz-Otero, Alvar; Liebe, Carl Christian; Hunter, Roger C.; Baker, Christopher
2017-01-01
This project will develop an efficient smoothing software for incremental estimation of the relative poses and velocities between multiple, small spacecraft in a formation, and a small, long range depth sensor based on coded aperture imaging that is capable of identifying other spacecraft in the formation. The smoothing algorithm will obtain the maximum a posteriori estimate of the relative poses between the spacecraft by using all available sensor information in the spacecraft formation.This algorithm will be portable between different satellite platforms that possess different sensor suites and computational capabilities, and will be adaptable in the case that one or more satellites in the formation become inoperable. It will obtain a solution that will approach an exact solution, as opposed to one with linearization approximation that is typical of filtering algorithms. Thus, the algorithms developed and demonstrated as part of this program will enhance the applicability of small spacecraft to multi-platform operations, such as precisely aligned constellations and fractionated satellite systems.
Effects of lubiprostone on human uterine smooth muscle cells.
Cuppoletti, John; Malinowska, Danuta H; Chakrabarti, Jayati; Ueno, Ryuji
2008-06-01
Lubiprostone, a bicyclic fatty acid derivative and member of a new class of compounds called prostones, locally activates ClC-2 Cl(-) channels without activation of prostaglandin receptors. The present study was specifically designed to test and compare lubiprostone and prostaglandin effects at the cellular level using human uterine smooth muscle cells. Effects on [Ca(2+)](i), membrane potential and [cAMP](i) in human uterine smooth muscle cells were measured. 10 nM lubiprostone significantly decreased [Ca(2+)](i) from 188 to 27 nM, which was unaffected by 100 nM SC-51322, a prostaglandin EP receptor antagonist. In contrast 10nM PGE(2) and PGE(1) both increased [Ca(2+)](i) 3-5-fold which was blocked by SC-51322. Similarly, lubiprostone and prostaglandins had opposite/different effects on membrane potential and [cAMP](i). Lubiprostone caused SC-51322-insensitive membrane hyperpolarization and no effect on [cAMP](i). PGE(2) and PGE(1) both caused SC-51322-sensitive membrane depolarization and increased [cAMP](i). Lubiprostone has fundamentally different cellular effects from prostaglandins that are not mediated by EP receptors.
Smooth time-dependent receiver operating characteristic curve estimators.
Martínez-Camblor, Pablo; Pardo-Fernández, Juan Carlos
2017-01-01
The receiver operating characteristic curve is a popular graphical method often used to study the diagnostic capacity of continuous (bio)markers. When the considered outcome is a time-dependent variable, two main extensions have been proposed: the cumulative/dynamic receiver operating characteristic curve and the incident/dynamic receiver operating characteristic curve. In both cases, the main problem for developing appropriate estimators is the estimation of the joint distribution of the variables time-to-event and marker. As usual, different approximations lead to different estimators. In this article, the authors explore the use of a bivariate kernel density estimator which accounts for censored observations in the sample and produces smooth estimators of the time-dependent receiver operating characteristic curves. The performance of the resulting cumulative/dynamic and incident/dynamic receiver operating characteristic curves is studied by means of Monte Carlo simulations. Additionally, the influence of the choice of the required smoothing parameters is explored. Finally, two real-applications are considered. An R package is also provided as a complement to this article.
Smooth Approximation of Lipschitz Functions on Finsler Manifolds
Directory of Open Access Journals (Sweden)
M. I. Garrido
2013-01-01
Full Text Available We study the smooth approximation of Lipschitz functions on Finsler manifolds, keeping control on the corresponding Lipschitz constants. We prove that, given a Lipschitz function f:M→ℝ defined on a connected, second countable Finsler manifold M, for each positive continuous function ε:M→(0,∞ and each r>0, there exists a C1-smooth Lipschitz function g:M→ℝ such that |f(x-g(x|≤ε(x, for every x∈M, and Lip(g≤Lip(f+r. As a consequence, we derive a completeness criterium in the class of what we call quasi-reversible Finsler manifolds. Finally, considering the normed algebra Cb1(M of all C1 functions with bounded derivative on a complete quasi-reversible Finsler manifold M, we obtain a characterization of algebra isomorphisms T:Cb1(N→Cb1(M as composition operators. From this we obtain a variant of Myers-Nakai Theorem in the context of complete reversible Finsler manifolds.
Contextual effects on smooth-pursuit eye movements.
Spering, Miriam; Gegenfurtner, Karl R
2007-02-01
Segregating a moving object from its visual context is particularly relevant for the control of smooth-pursuit eye movements. We examined the interaction between a moving object and a stationary or moving visual context to determine the role of the context motion signal in driving pursuit. Eye movements were recorded from human observers to a medium-contrast Gaussian dot that moved horizontally at constant velocity. A peripheral context consisted of two vertically oriented sinusoidal gratings, one above and one below the stimulus trajectory, that were either stationary or drifted into the same or opposite direction as that of the target at different velocities. We found that a stationary context impaired pursuit acceleration and velocity and prolonged pursuit latency. A drifting context enhanced pursuit performance, irrespective of its motion direction. This effect was modulated by context contrast and orientation. When a context was briefly perturbed to move faster or slower eye velocity changed accordingly, but only when the context was drifting along with the target. Perturbing a context into the direction orthogonal to target motion evoked a deviation of the eye opposite to the perturbation direction. We therefore provide evidence for the use of absolute and relative motion cues, or motion assimilation and motion contrast, for the control of smooth-pursuit eye movements.
On Smooth Time-Dependent Orbifolds and Null Singularities
Energy Technology Data Exchange (ETDEWEB)
Fabinger, Michel
2002-08-08
We study string theory on a non-singular time-dependent orbifold of flat space. The orbifold group, which involves only space-like identifications, is obtained by a combined action of a null Lorentz transformation and a constant shift in an extra direction. In the limit where the shift goes to zero, the geometry of this orbifold reproduces an orbifold with a light-like singularity, which was recently studied by Liu, Moore and Seiberg (hep-th/0204168). We find that the backreaction on the geometry due to a test particle can be made arbitrarily small, and that there are scattering processes which can be studied in the approximation of a constant background. We quantize strings on this orbifold and calculate the torus partition function. We construct a basis of states on the smooth orbifold whose tree level string interactions are nonsingular. We discuss the existence of physical modes in the singular orbifold which resolve the singularity. We also describe another way of making the singular orbifold smooth which involves a sandwich pp-wave.
ANALYSIS ON CENSORED QUANTILE RESIDUAL LIFE MODEL VIA SPLINE SMOOTHING.
Ma, Yanyuan; Wei, Ying
2012-01-01
We propose a general class of quantile residual life models, where a specific quantile of the residual life time, conditional on an individual has survived up to time t, is a function of certain covariates with their coefficients varying over time. The varying coefficients are assumed to be smooth unspecified functions of t. We propose to estimate the coefficient functions using spline approximation. Incorporating the spline representation directly into a set of unbiased estimating equations, we obtain a one-step estimation procedure, and we show that this leads to a uniformly consistent estimator. To obtain further computational simplification, we propose a two-step estimation approach in which we estimate the coefficients on a series of time points first, and follow this with spline smoothing. We compare the two methods in terms of their asymptotic efficiency and computational complexity. We further develop inference tools to test the significance of the covariate effect on residual life. The finite sample performance of the estimation and testing procedures are further illustrated through numerical experiments. We also apply the methods to a data set from a neurological study.
Response properties of MST parafoveal neurons during smooth pursuit adaptation.
Ono, Seiji; Mustari, Michael J
2016-07-01
Visual motion neurons in the posterior parietal cortex play a critical role in the guidance of smooth pursuit eye movements. Initial pursuit (open-loop period) is driven, in part, by visual motion signals from cortical areas, such as the medial superior temporal area (MST). The purpose of this study was to determine whether adaptation of initial pursuit gain arises because of altered visual sensitivity of neurons at the cortical level. It is well known that the visual motion response in MST is suppressed after exposure to a large-field visual motion stimulus, showing visual motion adaptation. One hypothesis is that foveal motion responses in MST are associated with smooth pursuit adaptation using a small target spot. We used a step-ramp tracking task with two steps of target velocity (double-step paradigm), which induces gain-down or gain-up adaptation. We found that after gain-down adaptation 58% of our MST visual neurons showed a significant decrease in firing rate. This was the case even though visual motion input (before the pursuit onset) from target motion was constant. Therefore, repetitive visual stimulation during the gain-down paradigm could lead to adaptive changes in the visual response. However, the time course of adaptation did not show a correlation between the visual response and pursuit behavior. These results indicate that the visual response in MST may not directly contribute to the adaptive change in pursuit initiation. Copyright © 2016 the American Physiological Society.
Assessing a 3D smoothed seismicity model of induced earthquakes
Zechar, Jeremy; Király, Eszter; Gischig, Valentin; Wiemer, Stefan
2016-04-01
As more energy exploration and extraction efforts cause earthquakes, it becomes increasingly important to control induced seismicity. Risk management schemes must be improved and should ultimately be based on near-real-time forecasting systems. With this goal in mind, we propose a test bench to evaluate models of induced seismicity based on metrics developed by the CSEP community. To illustrate the test bench, we consider a model based on the so-called seismogenic index and a rate decay; to produce three-dimensional forecasts, we smooth past earthquakes in space and time. We explore four variants of this model using the Basel 2006 and Soultz-sous-Forêts 2004 datasets to make short-term forecasts, test their consistency, and rank the model variants. Our results suggest that such a smoothed seismicity model is useful for forecasting induced seismicity within three days, and giving more weight to recent events improves forecast performance. Moreover, the location of the largest induced earthquake is forecast well by this model. Despite the good spatial performance, the model does not estimate the seismicity rate well: it frequently overestimates during stimulation and during the early post-stimulation period, and it systematically underestimates around shut-in. In this presentation, we also describe a robust estimate of information gain, a modification that can also benefit forecast experiments involving tectonic earthquakes.
Ultrafine and Smooth Full Metal Nanostructures for Plasmonics
Zhu, Xinli; Zhang, Jaseng; Xu, Jun; Liao, Zhimin; Wu, Xiaosong; Yu, Dapeng
2013-03-01
Surface plasmon polaritons (SPPs), which are coupled excitations of electrons bound to a metal-dielectric interface, show great potential for application in future nanoscale photonic systems due to the strong field confinement at the nanoscale, intensive local field enhancement, and interplay between strongly localized and propagating SPPs. The fabrication of sufficiently smooth metal surface with nanoscale feature size is crucial for SPPs to have practical applications. A template stripping (ST) method combined with PMMA as a template was successfully developed to create extraordinarily smooth metal nanostructures with a desirable feature size and morphology for plasmonics and metamaterials. The advantages of this method, including the high resolution, precipitous top-to bottom profile with a high aspect ratio, and three-dimensional characteristics, make it very suitable for the fabrication of plasmonic structures. By using this ST method, boxing ring-shaped nanocavities have been fabricated and the confined modes of surface plasmon polaritons in these nanocavities have been investigated and imaged by using cathodoluminescence spectroscopy. The mode of the out-of-plane field components of surface plasmon polaritons dominates the experimental mode patterns, indicating that the electron beam locally excites the out-of-plane field component of surface plasmon polaritons, and quality factors can be directly acquired. Numerous applications, such as plasmonic filter, nanolaser, and efficient light-emitting devices, can be expected to arise from these developments.
MicroRNAs dynamically remodel gastrointestinal smooth muscle cells.
Directory of Open Access Journals (Sweden)
Chanjae Park
2011-04-01
Full Text Available Smooth muscle cells (SMCs express a unique set of microRNAs (miRNAs which regulate and maintain the differentiation state of SMCs. The goal of this study was to investigate the role of miRNAs during the development of gastrointestinal (GI SMCs in a transgenic animal model. We generated SMC-specific Dicer null animals that express the reporter, green fluorescence protein, in a SMC-specific manner. SMC-specific knockout of Dicer prevented SMC miRNA biogenesis, causing dramatic changes in phenotype, function, and global gene expression in SMCs: the mutant mice developed severe dilation of the intestinal tract associated with the thinning and destruction of the smooth muscle (SM layers; contractile motility in the mutant intestine was dramatically decreased; and SM contractile genes and transcriptional regulators were extensively down-regulated in the mutant SMCs. Profiling and bioinformatic analyses showed that SMC phenotype is regulated by a complex network of positive and negative feedback by SMC miRNAs, serum response factor (SRF, and other transcriptional factors. Taken together, our data suggest that SMC miRNAs are required for the development and survival of SMCs in the GI tract.
Smoothness of chewing jaw movements in adults with mandibular prognathism.
Yashiro, K; Takagi, M; Takada, K
2012-02-01
Indices such as smoothness, movement time, peak velocity, and symmetry of the velocity profile have been shown to be effective in explaining the degree of skilfulness of human saccadic eye, limb, and jaw motions. We investigated whether adult subjects with mandibular prognathism show impaired smoothness of the masticatory jaw movements. Forty-nine adults with skeletal Class III malocclusions and 52 healthy adults with acceptably good occlusions were selected respectively as Test and Control subjects. Subjects of the Test Group were subdivided into two groups: Class III(closed) showed full occlusal contact between the upper and lower teeth at the habitual intercuspal position, whereas Class III(open) showed inability of occlusal contact between the upper and lower anterior teeth. Each subject was asked to chew a piece of chewing gum. The normalised jerk-cost (NJC), movement duration, and tangential velocity profile during jaw-closing movements were compared between groups. Test Groups showed greater NJC (P Control Group did. Class III(closed) showed greater NJC (P Control Group. The jaw movement skilfulness of the prognathic patients decreases most drastically with existence of malocclusal contact between upper and lower anterior teeth. © 2011 Blackwell Publishing Ltd.
Biophysical induction of vascular smooth muscle cell podosomes.
Directory of Open Access Journals (Sweden)
Na Young Kim
Full Text Available Vascular smooth muscle cell (VSMC migration and matrix degradation occurs with intimal hyperplasia associated with atherosclerosis, vascular injury, and restenosis. One proposed mechanism by which VSMCs degrade matrix is through the use of podosomes, transient actin-based structures that are thought to play a role in extracellular matrix degradation by creating localized sites of matrix metalloproteinase (MMP secretion. To date, podosomes in VSMCs have largely been studied by stimulating cells with phorbol esters, such as phorbol 12,13-dibutyrate (PDBu, however little is known about the physiological cues that drive podosome formation. We present the first evidence that physiological, physical stimuli mimicking cues present within the microenvironment of diseased arteries can induce podosome formation in VSMCs. Both microtopographical cues and imposed pressure mimicking stage II hypertension induce podosome formation in A7R5 rat aortic smooth muscle cells. Moreover, wounding using a scratch assay induces podosomes at the leading edge of VSMCs. Notably the effect of each of these biophysical stimuli on podosome stimulation can be inhibited using a Src inhibitor. Together, these data indicate that physical cues can induce podosome formation in VSMCs.
Directional bilateral filters for smoothing fluorescence microscopy images
Directory of Open Access Journals (Sweden)
Manasij Venkatesh
2015-08-01
Full Text Available Images obtained through fluorescence microscopy at low numerical aperture (NA are noisy and have poor resolution. Images of specimens such as F-actin filaments obtained using confocal or widefield fluorescence microscopes contain directional information and it is important that an image smoothing or filtering technique preserve the directionality. F-actin filaments are widely studied in pathology because the abnormalities in actin dynamics play a key role in diagnosis of cancer, cardiac diseases, vascular diseases, myofibrillar myopathies, neurological disorders, etc. We develop the directional bilateral filter as a means of filtering out the noise in the image without significantly altering the directionality of the F-actin filaments. The bilateral filter is anisotropic to start with, but we add an additional degree of anisotropy by employing an oriented domain kernel for smoothing. The orientation is locally adapted using a structure tensor and the parameters of the bilateral filter are optimized for within the framework of statistical risk minimization. We show that the directional bilateral filter has better denoising performance than the traditional Gaussian bilateral filter and other denoising techniques such as SURE-LET, non-local means, and guided image filtering at various noise levels in terms of peak signal-to-noise ratio (PSNR. We also show quantitative improvements in low NA images of F-actin filaments.
Visible spectrum of stable sonoluminescence
Carlson, Joseph T.
1992-12-01
Synchronous emissions of picosecond pulses of light are observed to originate from a bubble trapped at the pressure antinode of a resonant sound field. The spectrum has been measured using a single slit spectrometer equipped with a linear array CCD detector. Spectra from differing solutions of water and glycerin are compared to the visible blackbody spectrum distribution. Assuming a blackbody model, apparent temperatures of 18,900 Kelvins are observed in pure water. Increasing glycerin concentration appears to correlate with cooler blackbody temperatures. The spectrum is also found to continually change with time, independent of input parameters.
Autism Spectrum Disorder and Fragile X Syndrome
... only after another family member has been diagnosed. Autism Spectrum Disorder and Fragile X Syndrome Fragile X ... known single gene cause of ASD What Is Autism Spectrum Disorder? Autism spectrum disorder (ASD) is a ...
WaVPeak: picking NMR peaks through wavelet-based smoothing and volume-based filtering.
Liu, Zhi; Abbas, Ahmed; Jing, Bing-Yi; Gao, Xin
2012-04-01
Nuclear magnetic resonance (NMR) has been widely used as a powerful tool to determine the 3D structures of proteins in vivo. However, the post-spectra processing stage of NMR structure determination usually involves a tremendous amount of time and expert knowledge, which includes peak picking, chemical shift assignment and structure calculation steps. Detecting accurate peaks from the NMR spectra is a prerequisite for all following steps, and thus remains a key problem in automatic NMR structure determination. We introduce WaVPeak, a fully automatic peak detection method. WaVPeak first smoothes the given NMR spectrum by wavelets. The peaks are then identified as the local maxima. The false positive peaks are filtered out efficiently by considering the volume of the peaks. WaVPeak has two major advantages over the state-of-the-art peak-picking methods. First, through wavelet-based smoothing, WaVPeak does not eliminate any data point in the spectra. Therefore, WaVPeak is able to detect weak peaks that are embedded in the noise level. NMR spectroscopists need the most help isolating these weak peaks. Second, WaVPeak estimates the volume of the peaks to filter the false positives. This is more reliable than intensity-based filters that are widely used in existing methods. We evaluate the performance of WaVPeak on the benchmark set proposed by PICKY (Alipanahi et al., 2009), one of the most accurate methods in the literature. The dataset comprises 32 2D and 3D spectra from eight different proteins. Experimental results demonstrate that WaVPeak achieves an average of 96%, 91%, 88%, 76% and 85% recall on (15)N-HSQC, HNCO, HNCA, HNCACB and CBCA(CO)NH, respectively. When the same number of peaks are considered, WaVPeak significantly outperforms PICKY. WaVPeak is an open source program. The source code and two test spectra of WaVPeak are available at http://faculty.kaust.edu.sa/sites/xingao/Pages/Publications.aspx. The online server is under construction. statliuzhi
Family Process - Autism Spectrum Disorders
Benson, Mark
2012-01-01
Slides for a talk about family process and the importance of parenting dimensions in adolescent development. The slides list findings to date, and propose research into the influence of family on outcomes for those diagnosed with an autism spectrum disorder.
Interaction between smooth anticipation and saccades during ocular orientation in darkness.
Blohm, Gunnar; Missal, Marcus; Lefèvre, Philippe
2003-03-01
A saccade triggered during sustained smooth pursuit is programmed using retinal information about the relative position and velocity of the target with respect to the eye. Thus the smooth pursuit and saccadic systems are coordinated by using common retinal inputs. Yet, in the absence of retinal information about the relative motion of the eye with respect to the target, the question arises whether the smooth and saccadic systems are still able to be coordinated possibly by using extraretinal information to account for the saccadic and smooth eye movements. To address this question, we flashed a target during smooth anticipatory eye movements in darkness, and the subjects were asked to orient their visual axis to the remembered location of the flash. We observed multiple orientation saccades (typically 2-3) toward the memorized location of the flash. The first orienting saccade was programmed using only the position error at the moment of the flash, and the smooth eye movement was ignored. However, subsequent saccades executed in darkness compensated gradually for the smooth eye displacement (mean compensation congruent with 70%). This behavior revealed a 400-ms delay in the time course of orientation for the compensation of the ongoing smooth eye displacement. We conclude that extraretinal information about the smooth motor command is available to the saccadic system in the absence of visual input. There is a 400-ms delay for smooth movement integration, saccade programming and execution.
Autism spectrum disorder - childhood disintegrative disorder
... part of the larger developmental disorder category of autism spectrum disorder . ... American Psychiatric Association. Autism spectrum disorder. ... ed. Arlington, VA: American Psychiatric Publishing: 2013;50-59. ...
Airway smooth muscle, tidal stretches, and dynamically determined contractile states.
Fredberg, J J; Inouye, D; Miller, B; Nathan, M; Jafari, S; Raboudi, S H; Butler, J P; Shore, S A
1997-12-01
In the classic theory of airway lumen narrowing in asthma, active force in airway smooth muscle is presumed to be in static mechanical equilibrium with the external load against which the muscle has shortened. This theory is useful because it identifies the static equilibrium length toward which activated airway smooth muscle would tend if given enough time. The corresponding state toward which myosin-actin interactions would tend is called the latch state. But are the concepts of a static mechanical equilibrium and the latch state applicable in the setting of tidal loading, as occurs during breathing? To address this question, we have studied isolated, maximally contracted bovine tracheal smooth muscle subjected to tidal stretches imposed at 0.33 Hz. We measured the active force (F) and stiffness (E), which reflect numbers of actin-myosin interactions, and hysteresivity (eta) which reflects the rate of turnover of those interactions. When the amplitude of imposed tidal stretch (epsilon) was very small, 0.25% of muscle optimal length, the steady-state value of F approximated the isometric force, E was large, and eta was small. When epsilon was increased beyond 1%, however, F and E promptly decreased and eta promptly increased. The muscle could be maintained in these steady, dynamically determined contractile states for as long as the tidal stretches were sustained; when epsilon subsequently decreased back to 0.25%, F, E, and eta returned slowly toward their previous values. The provocative stretch amplitude required to cause active force or muscle stiffness to fall by half, or hysteresivity to double, was slightly greater than 2%. These observations are consistent with a direct effect of stretch upon bridge dynamics in which, with increasing tidal stretch amplitude, the number of actin-myosin interactions decreases and their rate of turnover increases. We conclude that the interactions of myosin with actin are at every instant tending toward those that would
Beyond the Spectrum: Rethinking Autism
Directory of Open Access Journals (Sweden)
Heather Thomas
2017-03-01
Full Text Available The "spectrum" has become the dominant metaphor for conceptualizing autism, with fundamental consequences for notions of disability, diversity, and normality. In this article, we draw on ethnographic research with autistic communities to explore how the notion of the autism spectrum has become a focus of explicit identification, reflection, and contestation. To further this inquiry, we place these debates into conversation with earlier debates regarding another spectrum—the Kinsey Scale, a "spectrum" for conceptualizing sexual orientation that first appeared in 1948 but has been critiqued since the 1970s. How might responses to the Kinsey Scale (like the Klein Grid contribute to rethinking the autism spectrum? This is a question about the cultural and political implications of metaphors and conceptual models. It is of broad importance because the spectrum metaphor is being extended to a range of conditions beyond autism itself. Our goal is thus to build on insights from sexuality studies as well as the insights of autistic persons, advocates, and researchers who wish to forestall the naturalization of "the spectrum." In doing so, we seek to contribute to a discussion of what alternative frameworks might bring to questions of social justice, ability, and human flourishing.
Dynamics of Traction Force Reinforcement in Smooth Muscle Cells
Lin, Yi-Chia; Kramer, Corinne; Chen, Christopher; Reich, Daniel
2010-03-01
Mechanical forces influence cell function in various ways. For instance, the force-induced contraction or relaxation of vascular smooth muscle cells (SMCs) is critical to regulating the properties of blood vessels. Here, we study the dynamics of cellular traction forces in SMCs using micro-scale magnetic nanowires together with flexible PDMS micropost arrays. We use dual magnetic tweezers to apply a sinusoidal magnetic torque on nickel nanowires which are internalized by the SMCs. The spatial and temporal responses of the SMCs cultured on the tips of the microposts are recorded by the deflected posts. We observe a global reinforcement of the cells' traction forces upon applying a localized torque via the nanowires. Interestingly, we also find that the contractile response depends on the frequency of the applied stimulation, with a greater percentage of the SMCs showing enhanced reinforcement at lower frequencies.
Efficient Estimation of Smooth Distributions From Coarsely Grouped Data
DEFF Research Database (Denmark)
Rizzi, Silvia; Gampe, Jutta; Eilers, Paul H C
2015-01-01
Ungrouping binned data can be desirable for many reasons: Bins can be too coarse to allow for accurate analysis; comparisons can be hindered when different grouping approaches are used in different histograms; and the last interval is often wide and open-ended and, thus, covers a lot of information...... in the tail area. Age group-specific disease incidence rates and abridged life tables are examples of binned data. We propose a versatile method for ungrouping histograms that assumes that only the underlying distribution is smooth. Because of this modest assumption, the approach is suitable for most...... to the estimation of rates when both the event counts and the exposures to risk are grouped....
Structure and Thermodynamics of Metal Clusters on Atomically Smooth Substrates.
Eckhoff, M; Schebarchov, D; Wales, D J
2017-10-23
We analyze the structure of model NiN and CuN clusters (N = 55, 147) supported on a variety of atomically smooth van der Waals surfaces. The global minima are mapped in the space of two parameters: (i) the laterally averaged surface stickiness, γ, which controls the macroscopic wetting angle, and (ii) the surface microstructure, which produces more subtle but important templating via epitaxial stresses. We find that adjusting the substrate lattice (even at constant γ) can favor different crystal plane orientations in the cluster, stabilize hexagonal close-packed order, or induce various defects, such as stacking faults, twin boundaries, and five-fold disclinations. Thermodynamic analysis reveals substrate-dependent solid-solid transitions in cluster morphology, with tunable transition temperature and sometimes exhibiting re-entrant behavior. These results shed new light on the extent to which a supporting surface can be used to influence the equilibrium behavior of nanoparticles.
Modeling Electrokinetic Flows by the Smoothed Profile Method
Luo, Xian; Beskok, Ali; Karniadakis, George Em
2010-01-01
We propose an efficient modeling method for electrokinetic flows based on the Smoothed Profile Method (SPM) [1–4] and spectral element discretizations. The new method allows for arbitrary differences in the electrical conductivities between the charged surfaces and the the surrounding electrolyte solution. The electrokinetic forces are included into the flow equations so that the Poisson-Boltzmann and electric charge continuity equations are cast into forms suitable for SPM. The method is validated by benchmark problems of electroosmotic flow in straight channels and electrophoresis of charged cylinders. We also present simulation results of electrophoresis of charged microtubules, and show that the simulated electrophoretic mobility and anisotropy agree with the experimental values. PMID:20352076
Feature-preserving surface mesh smoothing via suboptimal Delaunay triangulation.
Gao, Zhanheng; Yu, Zeyun; Holst, Michael
2013-01-01
A method of triangular surface mesh smoothing is presented to improve angle quality by extending the original optimal Delaunay triangulation (ODT) to surface meshes. The mesh quality is improved by solving a quadratic optimization problem that minimizes the approximated interpolation error between a parabolic function and its piecewise linear interpolation defined on the mesh. A suboptimal problem is derived to guarantee a unique, analytic solution that is significantly faster with little loss in accuracy as compared to the optimal one. In addition to the quality-improving capability, the proposed method has been adapted to remove noise while faithfully preserving sharp features such as edges and corners of a mesh. Numerous experiments are included to demonstrate the performance of the method.
Day-Ahead Load Forecasting Using Exponential Smoothing
Directory of Open Access Journals (Sweden)
R. Bindiu
2009-12-01
Full Text Available The existence of a liberated market for electricity implies the necessity of using load forecasting in order to optimize and reduce the costs for the electric energy consumption. Different strategies for the purchase of electrical energy require precise load forecasting. The Day Ahead Market makes possible the acquisition of electricity for one day in advance. This reduces the risk of making electrical energy transactions on Balance Market, which means buying at a very high price and selling at a very low price. This paper presents a Day Ahead Load Forecasting approach for an industrial costumer using exponential smoothing method. The purpose of this paper is to present a new method for day ahead load forecasting.
Membrane Currents in Airway Smooth Muscle: Mechanisms and Therapeutic Implications
Directory of Open Access Journals (Sweden)
Luke J Janssen
1997-01-01
Full Text Available Electrophysiological and pharmacological techniques were used to characterize the membrane conductance changes underlying spasmogen-evoked depolarization in airway smooth muscle (ASM. Changes included a transient activation of chloride ion channels and prolonged suppression of potassium ion channels; both changes are triggered by release of internally sequestered calcium ion and in turn cause opening of voltage-dependent calcium channels. The resultant influx of calcium ions contributes to contraction as well as to refilling of the internal calcium ion pool. Bronchodilators, on the other hand, act in part through activation of potassium channels, with consequent closure of calcium channels. The tools used to study ion channels in ASM are described, and the investigations of the roles of ion channels in ASM physiology (autacoid-evoked depolarization and hyperpolarization and pathophysiology (airway hyperresponsiveness are summarized. Finally, how the relationship between ion channels and ASM function/dysfunction may relate to the treatment of asthma and related breathing disorders is discussed.
Vascular smooth muscle function: defining the diabetic vascular phenotype.
Bruno, Rosa Maria; Ghiadoni, Lorenzo
2013-10-01
In this issue of Diabetologia, a meta-analysis performed by Montero and co-authors (Diabetologia doi 10.1007/s00125-013-2974-1 ) demonstrates a significant impairment of vascular smooth muscle (VSM) function in type 2 diabetic patients. Endothelial function and VSM function between type 2 diabetic and healthy individuals were associated, especially in the microcirculation, confirming the hypothesis that unresponsiveness of VSM cells to NO may amplify the consequences of reduced NO availability. This study suggests a novel interpretation for endothelial dysfunction in diabetic patients, indicating VSM cells as key players. Causative mechanisms of VSM dysfunction, which seems to be a feature of the vascular phenotype of type 2 diabetes mellitus, are largely unexplored in humans. Future studies should also address the crucial issue of the prognostic significance of VSM dysfunction in diabetic patients, and possibly in other conditions characterised by high cardiovascular risk.
Voltage harmonic elimination with RLC based interface smoothing filter
Chandrasekaran, K.; Ramachandaramurthy, V. K.
2015-04-01
A method is proposed for designing a Dynamic Voltage Restorer (DVR) with RLC interface smoothing filter. The RLC filter connected between the IGBT based Voltage Source Inverter (VSI) is attempted to eliminate voltage harmonics in the busbar voltage and switching harmonics from VSI by producing a PWM controlled harmonic voltage. In this method, the DVR or series active filter produces PWM voltage that cancels the existing harmonic voltage due to any harmonic voltage source. The proposed method is valid for any distorted busbar voltage. The operating VSI handles no active power but only harmonic power. The DVR is able to suppress the lower order switching harmonics generated by the IGBT based VSI. Good dynamic and transient results obtained. The Total Harmonic Distortion (THD) is minimized to zero at the sensitive load end. Digital simulations are carried out using PSCAD/EMTDC to validate the performance of RLC filter. Simulated results are presented.
Numerical modelling of extreme waves by Smoothed Particle Hydrodynamics
Directory of Open Access Journals (Sweden)
M. H. Dao
2011-02-01
Full Text Available The impact of extreme/rogue waves can lead to serious damage of vessels as well as marine and coastal structures. Such extreme waves in deep water are characterized by steep wave fronts and an energetic wave crest. The process of wave breaking is highly complex and, apart from the general knowledge that impact loadings are highly impulsive, the dynamics of the breaking and impact are still poorly understood. Using an advanced numerical method, the Smoothed Particle Hydrodynamics enhanced with parallel computing is able to reproduce well the extreme waves and their breaking process. Once the waves and their breaking process are modelled successfully, the dynamics of the breaking and the characteristics of their impact on offshore structures could be studied. The computational methodology and numerical results are presented in this paper.
Optimized first-order methods for smooth convex minimization.
Kim, Donghwan; Fessler, Jeffrey A
2016-09-01
We introduce new optimized first-order methods for smooth unconstrained convex minimization. Drori and Teboulle [5] recently described a numerical method for computing the N-iteration optimal step coefficients in a class of first-order algorithms that includes gradient methods, heavy-ball methods [15], and Nesterov's fast gradient methods [10,12]. However, the numerical method in [5] is computationally expensive for large N, and the corresponding numerically optimized first-order algorithm in [5] requires impractical memory and computation for large-scale optimization problems. In this paper, we propose optimized first-order algorithms that achieve a convergence bound that is two times smaller than for Nesterov's fast gradient methods; our bound is found analytically and refines the numerical bound in [5]. Furthermore, the proposed optimized first-order methods have efficient forms that are remarkably similar to Nesterov's fast gradient methods.
Numerical simulation of explosive welding using Smoothed Particle Hydrodynamics method
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J Feng
2017-09-01
Full Text Available In order to investigate the mechanism of explosive welding and the influences of explosive welding parameters on the welding quality, this paper presents numerical simulation of the explosive welding of Al-Mg plates using Smoothed Particle Hydrodynamics method. The multi-physical phenomena of explosive welding, including acceleration of the flyer plate driven by explosive detonation, oblique collision of the flyer and base plates, jetting phenomenon and the formation of wavy interface can be reproduced in the simulation. The characteristics of explosive welding are analyzed based on the simulation results. The mechanism of wavy interface formation is mainly due to oscillation of the collision point on the bonding surfaces. In addition, the impact velocity and collision angle increase with the increase of the welding parameters, such as explosive thickness and standoff distance, resulting in enlargement of the interfacial waves.
A Consistent Adaptive-resolution Smoothed Particle Hydrodynamics Method
Pan, Wenxiao; Hu, Wei; Hu, Xiaozhe; Negrut, Dan; Univ of Wisconsin, Madison Collaboration; Tufts University Collaboration
2017-11-01
We seek to accelerate and increase the size of simulations for fluid-structure interactions (FSI) by using adaptive resolutions in the spatial discretization of the equations governing the time evolution of systems displaying two-way fluid-solid coupling. To this end, we propose an adaptive-resolution smoothed particle hydrodynamics (SPH) approach, in which spatial resolutions adaptively vary according to a recovery-based error estimator of velocity gradient as flow evolves. The second-order consistent discretization of spatial differential operators is employed to ensure the accuracy of the proposed method. The convergence, accuracy, and efficiency attributes of the new method are assessed by simulating different flows. In this process, the numerical results are compared to the analytical, finite element, and consistent SPH single-resolution solutions. We anticipate that the proposed adaptive-resolution method will enlarge the class of SPH-tractable FSI applications.
Memory-Based Learning Using Similarity for Smoothing
Zavrel, J; Zavrel, Jakub; Daelemans, Walter
1997-01-01
This paper analyses the relation between the use of similarity in Memory-Based Learning and the notion of backed-off smoothing in statistical language modeling. We show that the two approaches are closely related, and we argue that feature weighting methods in the Memory-Based paradigm can offer the advantage of automatically specifying a suitable domain-specific hierarchy between most specific and most general conditioning information without the need for a large number of parameters. We report two applications of this approach: PP-attachment and POS-tagging. Our method achieves state-of-the-art performance in both domains, and allows the easy integration of diverse information sources, such as rich lexical representations.
Smoothing effects for the filtration equation with different powers
Fotache, Alin Razvan; Muratori, Matteo
2017-09-01
We study the nonlinear diffusion equation ut = Δϕ (u) on general Euclidean domains, with homogeneous Neumann boundary conditions. We assume that ϕ‧ (u) is bounded from below by | u| m1 - 1 for small | u | and by | u| m2 - 1 for large | u |, the two exponents m1 ,m2 being possibly different and larger than one. The equality case corresponds to the well-known porous medium equation. We establish sharp short- and long-time L q0-L∞ smoothing estimates: similar issues have widely been investigated in the literature in the last few years, but the Neumann problem with different powers had not been addressed yet. This work extends some previous results in many directions.
Pattern recognition issues on anisotropic smoothed particle hydrodynamics
Pereira Marinho, Eraldo
2014-03-01
This is a preliminary theoretical discussion on the computational requirements of the state of the art smoothed particle hydrodynamics (SPH) from the optics of pattern recognition and artificial intelligence. It is pointed out in the present paper that, when including anisotropy detection to improve resolution on shock layer, SPH is a very peculiar case of unsupervised machine learning. On the other hand, the free particle nature of SPH opens an opportunity for artificial intelligence to study particles as agents acting in a collaborative framework in which the timed outcomes of a fluid simulation forms a large knowledge base, which might be very attractive in computational astrophysics phenomenological problems like self-propagating star formation.
Gasoline2: a modern smoothed particle hydrodynamics code
Wadsley, James W.; Keller, Benjamin W.; Quinn, Thomas R.
2017-10-01
The methods in the Gasoline2 smoothed particle hydrodynamics (SPH) code are described and tested. Gasoline2 is the most recent version of the Gasoline code for parallel hydrodynamics and gravity with identical hydrodynamics to the Changa code. As with other Modern SPH codes, we prevent sharp jumps in time-steps, use upgraded kernels and larger neighbour numbers and employ local viscosity limiters. Unique features in Gasoline2 include its Geometric Density Average Force expression, explicit Turbulent Diffusion terms and Gradient-Based shock detection to limit artificial viscosity. This last feature allows Gasoline2 to completely avoid artificial viscosity in non-shocking compressive flows. We present a suite of tests demonstrating the value of these features with the same code configuration and parameter choices used for production simulations.
A corrected solid boundary treatment method for Smoothed Particle Hydrodynamics
Chen, Yun-sai; Zheng, Xing; Jin, Shan-qin; Duan, Wen-yang
2017-04-01
Smoothed Particle Hydrodynamics method (SPH) has a good adaptability for simulating of free surface flow problems. However, there are some shortcomings of SPH which are still in open discussion. This paper presents a corrected solid boundary handling method for weakly compressible SPH. This improved method is very helpful for numerical stability and pressure distribution. Compared with other solid boundary handling methods, this corrected method is simpler for virtual ghost particle interpolation and the ghost particle evaluation relationship is clearer. Several numerical tests are given, like dam breaking, solitary wave impact and sloshing tank waves. The results show that the corrected solid boundary processing method can recover the spurious oscillations of pressure distribution when simulating the problems with complex geometry boundary.
Scaling laws for implicit viscosities in smoothed particle hydrodynamics
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Bierwisch Claas
2017-01-01
Full Text Available Smoothed particle hydrodynamics (SPH is a particle-based method which solves continuum equations such as the Navier-Stokes equations. A periodic fluidic system under homogeneous shear is studied using SPH in the present work. The total pressure of the system and the shear stress contributions from the SPH interaction terms for pressure and viscosity as well as the contribution caused by velocity fluctuations are analyzed. It is found that the pressure and the shear stress contributions obey certain scaling laws depending on physical properties of the system such as compressibility, viscosity and shear rate as well as the spatial resolution. Some of the identified relations resemble scaling laws for the rheology of dense granular flows. These findings render an assessment of the convergence with respect to the spatial resolution of SPH simulations possible. Furthermore, the similarities between numerical SPH particles and physical grains in dense flow provide a deeper understanding of the nature of the SPH method.
Scaling laws for implicit viscosities in smoothed particle hydrodynamics
Bierwisch, Claas; Polfer, Pit
2017-06-01
Smoothed particle hydrodynamics (SPH) is a particle-based method which solves continuum equations such as the Navier-Stokes equations. A periodic fluidic system under homogeneous shear is studied using SPH in the present work. The total pressure of the system and the shear stress contributions from the SPH interaction terms for pressure and viscosity as well as the contribution caused by velocity fluctuations are analyzed. It is found that the pressure and the shear stress contributions obey certain scaling laws depending on physical properties of the system such as compressibility, viscosity and shear rate as well as the spatial resolution. Some of the identified relations resemble scaling laws for the rheology of dense granular flows. These findings render an assessment of the convergence with respect to the spatial resolution of SPH simulations possible. Furthermore, the similarities between numerical SPH particles and physical grains in dense flow provide a deeper understanding of the nature of the SPH method.
On the problems of non-smooth railway vehicle dynamics
DEFF Research Database (Denmark)
Thomsen, Per Grove; True, Hans
2005-01-01
Railway vehicle dynamics is inherently a problem of nonlinear dynamics. The unavoidable nonlinearities stem from the rail/wheel contact geometry and the stress/strain velocity relation in the rail/wheel contact surface. In addition motion delimiters and dry friction contact between elements...... in the construction create discontinuities in the mathematical dynamic model. The stick/slip of dry friction can be modelled as a discontinuity or be smoothed whereby discontinuities of higher order spatial derivatives are introduced. Higher order discontinuities are also introduced through the rail/wheel contact...... relation. These discontinuities create problems for the advanced equation solvers that are needed for the numerical investigation of the nonlinear dynamic problem. The results of the integration of the dynamic system will depend on the correct choice and application of the solver. In the worst case...
Simulated Hypergravity Alters Vascular Smooth Muscle Cell Proliferation and Motility
Hunt, Shameka; Bettis, Barika; Harris-Hooker, Sandra; Sanford, Gary L.
1997-01-01
The cellular effects of gravity are poorly understood due to its constancy and nonavailability of altered gravitational models. Such an understanding is crucial for prolonged space flights. In these studies, we assessed the influence of centrifugation at 6G (HGrav) on vascular smooth muscle (SMC) mobility and proliferation. Cells were: (a) plated at low density and subjected to HGrav for 24-72 hr for proliferation studies, or (b) grown to confluency, subjected to HGrav, mechanically denuded and monitored for cell movement into the denuded area. Controls were maintained under normogravity. SMC showed a 50% inhibition of growth under HGrav and 10% serum; HGrav and low serum resulted in greater growth inhibition. The rate of movement of SMC into the denuded area was 2-3-fold higher under HGrav in low serum compared to controls, but similar in 10% serum. These studies show that HGrav has significant effects on SMC growth and mobility, which are dependent on serum levels.
CRKSPH - A Conservative Reproducing Kernel Smoothed Particle Hydrodynamics Scheme
Frontiere, Nicholas; Owen, J Michael
2016-01-01
We present a formulation of smoothed particle hydrodynamics (SPH) that employs a first-order consistent reproducing kernel function, exactly interpolating linear fields with particle tracers. Previous formulations using reproducing kernel (RK) interpolation have had difficulties maintaining conservation of momentum due to the fact the RK kernels are not, in general, spatially symmetric. Here, we utilize a reformulation of the fluid equations such that mass, momentum, and energy are all manifestly conserved without any assumption about kernel symmetries. Additionally, by exploiting the increased accuracy of the RK method's gradient, we formulate a simple limiter for the artificial viscosity that reduces the excess diffusion normally incurred by the ordinary SPH artificial viscosity. Collectively, we call our suite of modifications to the traditional SPH scheme Conservative Reproducing Kernel SPH, or CRKSPH. CRKSPH retains the benefits of traditional SPH methods (such as preserving Galilean invariance and manif...
Protostellar jets and magnetised turbulence with smoothed particle magnetohydrodynamics
Tricco, Terrence
2016-01-01
Magnetic fields are an integral component of the formation of stars. During my thesis work, I built new methods to model magnetic fields in smoothed particle magnetohydrodynamics which enforce the divergence-free constraint on the magnetic field and reduce numerical dissipation of the magnetic field. Using these methods, we have performed simulations of isolated protostar formation, studying the production of jets and outflows of material and their effect on transporting angular momentum away from the protostar and reducing the efficiency of star formation. A major code comparison project on the small-scale turbulent dynamo amplification of magnetic fields was performed, using conditions representative of molecular clouds, the formation site of stars. The results were compared against results from grid-based methods, finding excellent agreement on their statistics and qualitative behaviour. I will outline the numerical methods developed, and present the results from our protostar and molecular cloud simulations.
A smoothed string-like braneworld in six dimensions
Energy Technology Data Exchange (ETDEWEB)
Araujo, J.C.B.; Silva, J.E.G.; Veras, D.F.S.; Almeida, C.A.S. [Universidade Federal do Ceara, Departamento de Fisica, C.P. 6030, Fortaleza, Ceara (Brazil)
2015-03-01
We propose a static and axisymmetric braneworld in six dimensions as a string-like model extension. For a subtle warp function, this scenario provides near brane corrections. By varying the bulk cosmological constant, we obtain a source which passes through different phases. The solution is defined both for the interior and for the exterior of the string and satisfies all the energy conditions. A smoothed gravitational massless mode is localized on the brane, of which the core is displaced from the origin. In contrast to the thin-string model, the massive solutions have a high amplitude near the brane. Furthermore, by means of an analog quantum potential analysis, we show that only s-wave gravitational Kaluza-Klein modes are permissible. (orig.)
Smoothing internal migration age profiles for comparative research
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Aude Bernard
2015-05-01
Full Text Available Background: Age patterns are a key dimension to compare migration between countries and over time. Comparative metrics can be reliably computed only if data capture the underlying age distribution of migration. Model schedules, the prevailing smoothing method, fit a composite exponential function, but are sensitive to function selection and initial parameter setting. Although non-parametric alternatives exist, their performance is yet to be established. Objective: We compare cubic splines and kernel regressions against model schedules by assessingwhich method provides an accurate representation of the age profile and best performs on metrics for comparing aggregate age patterns. Methods: We use full population microdata for Chile to perform 1,000 Monte-Carlo simulations for nine sample sizes and two spatial scales. We use residual and graphic analysis to assess model performance on the age and intensity at which migration peaks and the evolution of migration age patterns. Results: Model schedules generate a better fit when (1 the expected distribution of the age profile is known a priori, (2 the pre-determined shape of the model schedule adequately describes the true age distribution, and (3 the component curves and initial parameter values can be correctly set. When any of these conditions is not met, kernel regressions and cubic splines offer more reliable alternatives. Conclusions: Smoothing models should be selected according to research aims, age profile characteristics, and sample size. Kernel regressions and cubic splines enable a precise representation of aggregate migration age profiles for most sample sizes, without requiring parameter setting or imposing a pre-determined distribution, and therefore facilitate objective comparison.
Apelin attenuates the osteoblastic differentiation of vascular smooth muscle cells.
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Peng-Fei Shan
Full Text Available Vascular calcification, which results from a process osteoblastic differentiation of vascular smooth muscle cells (VSMCs, is a major risk factor for cardiovascular morbidity and mortality. Apelin is a recently discovered peptide that is the endogenous ligand for the orphan G-protein-coupled receptor, APJ. Several studies have identified the protective effects of apelin on the cardiovascular system. However, the effects and mechanisms of apelin on the osteoblastic differentiation of VSMCs have not been elucidated. Using a culture of calcifying vascular smooth muscle cells (CVMSCs as a model for the study of vascular calcification, the relationship between apelin and the osteoblastic differentiation of VSMCs and the signal pathway involved were investigated. Alkaline phosphatase (ALP activity and osteocalcin secretion were examined in CVSMCs. The involved signal pathway was studied using the extracellular signal-regulated kinase (ERK inhibitor, PD98059, the phosphatidylinositol 3-kinase (PI3-K inhibitor, LY294002, and APJ siRNA. The results showed that apelin inhibited ALP activity, osteocalcin secretion, and the formation of mineralized nodules. APJ protein was detected in CVSMCs, and apelin activated ERK and AKT (a downstream effector of PI3-K. Suppression of APJ with siRNA abolished the apelin-induced activation of ERK and Akt. Furthermore, inhibition of APJ expression, and the activation of ERK or PI3-K, reversed the effects of apelin on ALP activity. These results showed that apelin inhibited the osteoblastic differentiation of CVSMCs through the APJ/ERK and APJ/PI3-K/AKT signaling pathway. Apelin appears to play a protective role against arterial calcification.
Kernel Smoothing Methods for Non-Poissonian Seismic Hazard Analysis
Woo, Gordon
2017-04-01
For almost fifty years, the mainstay of probabilistic seismic hazard analysis has been the methodology developed by Cornell, which assumes that earthquake occurrence is a Poisson process, and that the spatial distribution of epicentres can be represented by a set of polygonal source zones, within which seismicity is uniform. Based on Vere-Jones' use of kernel smoothing methods for earthquake forecasting, these methods were adapted in 1994 by the author for application to probabilistic seismic hazard analysis. There is no need for ambiguous boundaries of polygonal source zones, nor for the hypothesis of time independence of earthquake sequences. In Europe, there are many regions where seismotectonic zones are not well delineated, and where there is a dynamic stress interaction between events, so that they cannot be described as independent. From the Amatrice earthquake of 24 August, 2016, the subsequent damaging earthquakes in Central Italy over months were not independent events. Removing foreshocks and aftershocks is not only an ill-defined task, it has a material effect on seismic hazard computation. Because of the spatial dispersion of epicentres, and the clustering of magnitudes for the largest events in a sequence, which might all be around magnitude 6, the specific event causing the highest ground motion can vary from one site location to another. Where significant active faults have been clearly identified geologically, they should be modelled as individual seismic sources. The remaining background seismicity should be modelled as non-Poissonian using statistical kernel smoothing methods. This approach was first applied for seismic hazard analysis at a UK nuclear power plant two decades ago, and should be included within logic-trees for future probabilistic seismic hazard at critical installations within Europe. In this paper, various salient European applications are given.
Smoothed dissipative particle dynamics with angular momentum conservation
Energy Technology Data Exchange (ETDEWEB)
Müller, Kathrin, E-mail: k.mueller@fz-juelich.de; Fedosov, Dmitry A., E-mail: d.fedosov@fz-juelich.de; Gompper, Gerhard, E-mail: g.gompper@fz-juelich.de
2015-01-15
Smoothed dissipative particle dynamics (SDPD) combines two popular mesoscopic techniques, the smoothed particle hydrodynamics and dissipative particle dynamics (DPD) methods, and can be considered as an improved dissipative particle dynamics approach. Despite several advantages of the SDPD method over the conventional DPD model, the original formulation of SDPD by Español and Revenga (2003) [9], lacks angular momentum conservation, leading to unphysical results for problems where the conservation of angular momentum is essential. To overcome this limitation, we extend the SDPD method by introducing a particle spin variable such that local and global angular momentum conservation is restored. The new SDPD formulation (SDPD+a) is directly derived from the Navier–Stokes equation for fluids with spin, while thermal fluctuations are incorporated similarly to the DPD method. We test the new SDPD method and demonstrate that it properly reproduces fluid transport coefficients. Also, SDPD with angular momentum conservation is validated using two problems: (i) the Taylor–Couette flow with two immiscible fluids and (ii) a tank-treading vesicle in shear flow with a viscosity contrast between inner and outer fluids. For both problems, the new SDPD method leads to simulation predictions in agreement with the corresponding analytical theories, while the original SDPD method fails to capture properly physical characteristics of the systems due to violation of angular momentum conservation. In conclusion, the extended SDPD method with angular momentum conservation provides a new approach to tackle fluid problems such as multiphase flows and vesicle/cell suspensions, where the conservation of angular momentum is essential.
Seismic hazard estimation of northern Iran using smoothed seismicity
Khoshnevis, Naeem; Taborda, Ricardo; Azizzadeh-Roodpish, Shima; Cramer, Chris H.
2017-07-01
This article presents a seismic hazard assessment for northern Iran, where a smoothed seismicity approach has been used in combination with an updated seismic catalog and a ground motion prediction equation recently found to yield good fit with data. We evaluate the hazard over a geographical area including the seismic zones of Azerbaijan, the Alborz Mountain Range, and Kopeh-Dagh, as well as parts of other neighboring seismic zones that fall within our region of interest. In the chosen approach, seismic events are not assigned to specific faults but assumed to be potential seismogenic sources distributed within regular grid cells. After performing the corresponding magnitude conversions, we decluster both historical and instrumental seismicity catalogs to obtain earthquake rates based on the number of events within each cell, and smooth the results to account for the uncertainty in the spatial distribution of future earthquakes. Seismicity parameters are computed for each seismic zone separately, and for the entire region of interest as a single uniform seismotectonic region. In the analysis, we consider uncertainties in the ground motion prediction equation, the seismicity parameters, and combine the resulting models using a logic tree. The results are presented in terms of expected peak ground acceleration (PGA) maps and hazard curves at selected locations, considering exceedance probabilities of 2 and 10% in 50 years for rock site conditions. According to our results, the highest levels of hazard are observed west of the North Tabriz and east of the North Alborz faults, where expected PGA values are between about 0.5 and 1 g for 10 and 2% probability of exceedance in 50 years, respectively. We analyze our results in light of similar estimates available in the literature and offer our perspective on the differences observed. We find our results to be helpful in understanding seismic hazard for northern Iran, but recognize that additional efforts are necessary to
Highly smooth Nb surfaces fabricated by buffered electropolishing
Energy Technology Data Exchange (ETDEWEB)
Andy T. Wu; John Mammossor; H. Phillips; Jean Delayen; Charles Reece; Amy Wilkerson; David Smith; Robert Ike
2005-05-01
It is demonstrated that highly smooth Nb surfaces can be obtained through Buffered ElectroPolishing (BEP) employing an electrolyte consisting of lactic, sulfuric, and hydrofluoric acids. Parameters that control the polishing process are optimized to achieve the smoothest surface finish with the help of surface observations using a scanning electron microscope and a Metallographic Optical Microscope (MOM). The polishing rate of BEP is determined to be 0.646 {micro}m/min that is much higher than 0.381 {micro}m/min achieved by the conventional ElectroPolishing (EP) process widely used in the Superconducting Radio Frequency (SRF) community. A high precision and large scan area 3-D profilometer is used to view morphology of the treated Nb surfaces. Statistical data, such as, rms, total indicator runout, and arithmetic mean deviation of the Nb surfaces are extracted from the profilometer images. It is found that Nb surfaces treated by BEP are an order of magnitude smoother than those treated by the optimized EP process. The chemical composition of the Nb surfaces after BEP is analyzed by static and dynamic Secondary Ion Mass Spectrometer (SIMS) systems. Cracking patterns of the Nb surfaces under different primary ion sources of Ga{sup +}, Au{sup +}, and Ar{sup +} are reported. The depth profile of the surface niobium oxides is studied through continuously monitoring niobium and its relevant oxides' peaks as a function of time. Dynamic SIMS results imply that the surface oxide structure of Nb may be more complicated than what usually believed and can be inhomogeneous. Preliminary results of BEP on Nb SRF single cell cavities and half-cells are reported. It is shown that smooth and bright surfaces can be obtained in 30 minutes when the electric field inside a SRF cavity is uniform during a BEP process. This study reveals that BEP is a highly promising technique for surface treatment on Nb SRF cavities to be used in particle accelerators.
Oxygen mediates vascular smooth muscle relaxation in hypoxia.
Directory of Open Access Journals (Sweden)
Jessica Dada
Full Text Available The activation of soluble guanylate cyclase (sGC by nitric oxide (NO and other ligands has been extensively investigated for many years. In the present study we considered the effect of molecular oxygen (O2 on sGC both as a direct ligand and its affect on other ligands by measuring cyclic guanosine monophosphate (cGMP production, as an index of activity, as well as investigating smooth muscle relaxation under hypoxic conditions. Our isolated enzyme studies confirm the function of sGC is impaired under hypoxic conditions and produces cGMP in the presence of O2, importantly in the absence of NO. We also show that while O2 could partially affect the magnitude of sGC stimulation by NO when the latter was present in excess, activation by the NO independent, haem-dependent sGC stimulator 3-(5'-hydroxymethyl-2'-furyl-1-benzylindazole (YC-1 was unaffected. Our in vitro investigation of smooth muscle relaxation confirmed that O2 alone in the form of a buffer bolus (equilibrated at 95% O2/5% CO2 had the ability to dilate vessels under hypoxic conditions and that this was dependent upon sGC and independent of eNOS. Our studies confirm that O2 can be a direct and important mediator of vasodilation through an increase in cGMP production. In the wider context, these observations are key to understanding the relative roles of O2 versus NO-induced sGC activation.
Directory of Open Access Journals (Sweden)
Raheela Akhtar1,2*, Yongqun O. He2, Charles B. Larson2, Zafar I. Chaudhary3 and Mansur ud-Din Ahmad4
2012-06-01
Full Text Available Brucella abortus lipopolysaccharide (LPS was isolated and purified from rough (RB51 and smooth (S2308 strains of Brucella. The LPS preparations were used to treat murine (RAW 264.7 macrophages in order to study their differential effects. Treated macrophages were tested by lysozyme release test (LRT, nitroblue tetrazolium test (NBT and nitric oxide (NO assay, respectively. Rough Brucella LPS induced significantly higher levels of lysozyme release, oxidative stress, and nitric oxide in murine macrophages than smooth Brucella LPS or combined LPS (rough + smooth LPS. These responses were dose-dependent. Macrophages treated with rough LPS were more Brucellacidal than those treated with smooth LPS. The minimal stimulation of murine macrophages by Brucella smooth LPS may provide basis for less active immune responses against smooth strains.
Gao, Harry; Kaweesa, Dorcas V.; Moore, Jacob; Meisel, Nicholas A.
2017-03-01
Acetone vapor smoothing is a chemical treatment that "melts" the surface of additively manufactured acrylonitrile butadiene styrene parts. The process fuses layers together and allows them to reform when vapor is removed, resulting in a smooth surface finish. Although commonly used to improve aesthetics, recent work has begun to investigate the effects of vapor smoothing on part strength. Nevertheless, most of this work has failed to take into account the anisotropic nature of printed parts. Prior research has shown that vapor smoothing reduces strength under best-case loading conditions, when the tensile load is parallel with the direction of the layers. In this article, the authors hypothesize that vapor smoothing may increase strength under nonoptimal loading conditions as a result of increased cohesion between layers and a reduction in stress concentrations. They use a design of experiments approach to identify the combined impact of printing and vapor smoothing parameters on part material properties.
[Phenotypic modulation of corpus cavernous smooth musle cells and its influencing factors].
Chen, Gang; Lü, Bo-dong; Huang, Xiao-jun
2010-03-01
Corpus cavernous smooth muscle cells are the main functional component of the corpus cavernosum penis, whose phenotypic modulation is the key initial step in the proliferation and migration of smooth muscle cells. Therefore, an insight into the mechanism of the phenotypic modulation of smooth muscle cells and its influencing factors is important for the prevention and management of penis erectile dysfunction. Smooth muscle cells are generally divided into contracting (differentiated) and composing (undifferentiated, proliferated or dedifferentiated) types. It is found that TGF-beta, transcription factor E2F1, BTEB2 and insulin may affect the phenotypic modulation of smooth muscle cells. This paper presents an overview of the progress in the researches on the phenotypic modulation of corpus cavernous smooth muscle cells and its influencing factors.
Krause, Katie M; Genest, Jerome
2006-07-01
The impact of the interferometer optical path difference (OPD) speed profile on the spectrum, derived through the use of Fourier-transform spectrometry (FTS), of a synchronous optical network (SONET) signal is found. The SONET signal carries high-speed data traffic. It also may be modulated by low-frequency intensity or frequency modulation. It is found that the SONET header, high-speed data traffic and low-frequency modulation all manifest themselves as artifacts in the FTS-derived spectrum of the SONET signal. It is shown that a nonconstant OPD speed profile can smooth out these artifacts, making it unlikely that they will be mistaken for carrier signal peaks. However, it is found that smoothing out these artifacts lessens the achievable dynamic range of the FTS instrument in the frequency range of interest, the International Telecommunications Union common (C) and long (L) bands.
Exact Filling of Figures with the Derivatives of Smooth Mappings Between Banach Spaces
Czech Academy of Sciences Publication Activity Database
Azagra, D.; Fabian, Marián; Jiménez-Sevilla, M.
2005-01-01
Roč. 48, č. 4 (2005), s. 481-499 ISSN 0008-4395 R&D Projects: GA AV ČR(CZ) IAA1019003; GA ČR(CZ) GA201/01/1198 Institutional research plan: CEZ:AV0Z10190503 Keywords : n-times smooth * Fréchet smooth * Gateaux smooth bump Subject RIV: BA - General Mathematics Impact factor: 0.316, year: 2005
A Pragmatic Smoothing Method for Improving the Quality of the Results in Atomic Spectroscopy
Bennun, Leonardo
2016-01-01
A new smoothing method for the improvement on the identification and quantification of spectral functions based on the previous knowledge of the signals that are expected to be quantified, is presented. These signals are used as weighted coefficients in the smoothing algorithm. This smoothing method was conceived to be applied in atomic and nuclear spectroscopies preferably to these techniques where net counts are proportional to acquisition time, such as particle induced X-ray emission (PIXE...
Ebeling, H; White, D.A.; Rangarajan, F. V. N.
2006-01-01
An efficient algorithm for adaptive kernel smoothing (AKS) of two-dimensional imaging data has been developed and implemented using the Interactive Data Language (IDL). The functional form of the kernel can be varied (top-hat, Gaussian etc.) to allow different weighting of the event counts registered within the smoothing region. For each individual pixel the algorithm increases the smoothing scale until the signal-to-noise ratio (s.n.r.) within the kernel reaches a preset value. Thus, noise i...
Components of the Hilbert scheme of space curves on low-degree smooth surfaces
Kleppe, Jan Oddvar; Ottem, John Christian
2015-01-01
We study maximal families W of the Hilbert scheme, H(d, g)sc, of smooth connected space curves whose general curve C lies on a smooth surface S of degree s. We give conditions on C under which W is a generically smooth component of H(d, g)sc and we determine dim W. If s = 4 and W is an irreducible component of H(d, g)sc, then the Picard number of S is at most 2 and we explicitly describe, also for s ≥ 5, non-reduced and generically smooth components in the case Pic(S) is generated by the clas...
Diagnosis of osteoarthritis by cartilage surface smoothness quantified automatically from knee MRI
DEFF Research Database (Denmark)
Tummala, Sudhakar; Bay-Jensen, Anne-Christine; Karsdal, Morten A.
2011-01-01
Objective: We investigated whether surface smoothness of articular cartilage in the medial tibiofemoral compartment quantified from magnetic resonance imaging (MRI) could be appropriate as a diagnostic marker of osteoarthritis (OA). Method: At baseline, 159 community-based subjects aged 21 to 81......, specifically cartilage volume from MRI, joint space width (JSW) from radiographs, and pain scores. Results: A total of 140 subjects concluded the 21-month study. Cartilage smoothness provided diagnostic ability in all compartments (P ... with pain severity (e.g., r = -0.32). The longitudinal change in smoothness was correlated with cartilage loss (r up to 0.60, P cartilage smoothness markers for diagnosis of moderate radiographic OA. Furthermore...
The Biokinetic Spectrum for Temperature
Corkrey, Ross; McMeekin, Tom A.; Bowman, John P.; Ratkowsky, David A.; Olley, June; Ross, Tom
2016-01-01
We identify and describe the distribution of temperature-dependent specific growth rates for life on Earth, which we term the biokinetic spectrum for temperature. The spectrum has the potential to provide for more robust modeling in thermal ecology since any conclusions derived from it will be based on observed data rather than using theoretical assumptions. It may also provide constraints for systems biology model predictions and provide insights in physiology. The spectrum has a Δ-shape with a sharp peak at around 42°C. At higher temperatures up to 60°C there was a gap of attenuated growth rates. We found another peak at 67°C and a steady decline in maximum rates thereafter. By using Bayesian quantile regression to summarise and explore the data we were able to conclude that the gap represented an actual biological transition between mesophiles and thermophiles that we term the Mesophile-Thermophile Gap (MTG). We have not identified any organism that grows above the maximum rate of the spectrum. We used a thermodynamic model to recover the Δ-shape, suggesting that the growth rate limits arise from a trade-off between activity and stability of proteins. The spectrum provides underpinning principles that will find utility in models concerned with the thermal responses of biological processes. PMID:27088362
Can the tinnitus spectrum identify tinnitus subgroups?
Heijneman, Karin M.; de Kleine, Emile; Wiersinga-Post, Esther; van Dijk, Pim
2013-01-01
The tinnitus spectrum is a psycho-acoustic metric of tinnitus. Previous work found a tight relation between the spectrum and the tone audiogram. This suggests that the spectrum and the audiogram provide essentially the same information, and the added value of the spectrum is limited. In order to
Energy Technology Data Exchange (ETDEWEB)
Hohenberger, M., E-mail: mhoh@lle.rochester.edu; Shvydky, A.; Marozas, J. A.; Bonino, M. J.; Canning, D.; Collins, T. J. B.; Dorrer, C.; Kessler, T. J.; Kruschwitz, B. E.; McKenty, P. W.; Regan, S. P.; Sangster, T. C.; Zuegel, J. D. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road Rochester, Rochester, New York 14623 (United States); Fiksel, G. [Nuclear Engineering and Radiological Sciences (NERS), University of Michigan, Ann Arbor, Michigan 48109 (United States); Meyerhofer, D. D. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
2016-09-15
Direct-drive ignition on the National Ignition Facility (NIF) requires single-beam smoothing to minimize imprinting of laser nonuniformities that can negatively affect implosion performance. One-dimensional, multi-FM smoothing by spectral dispersion (SSD) has been proposed to provide the required smoothing [Marozas et al., Bull. Am. Phys. Soc. 55, 294 (2010)]. A prototype multi-FM SSD system has been integrated into the NIF-like beamline of the OMEGA EP Laser System. Experiments have been performed to verify the smoothing performance by measuring Rayleigh–Taylor growth rates in planar targets of laser-imprinted and preimposed surface modulations. Multi-FM 1-D SSD has been observed to reduce imprint levels by ∼50% compared to the nominal OMEGA EP SSD system. The experimental results are in agreement with 2-D DRACO simulations using realistic, time-dependent far-field spot-intensity calculations that emulate the effect of SSD.
Luminosity Spectrum Reconstruction at Linear Colliders
Poss, Stéphane
2014-04-11
A good knowledge of the luminosity spectrum is mandatory for many measurements at future e+e- colliders. As the beam-parameters determining the luminosity spectrum cannot be measured precisely, the luminosity spectrum has to be measured through a gauge process with the detector. The measured distributions, used to reconstruct the spectrum, depend on Initial State Radiation, cross-section, and Final State Radiation. To extract the basic luminosity spectrum, a parametric model of the luminosity spectrum is created, in this case the spectrum at the 3 TeV Compact Linear Collider (CLIC). The model is used within a reweighting technique to extract the luminosity spectrum from measured Bhabha event observables, taking all relevant effects into account. The centre-of-mass energy spectrum is reconstructed within 5% over the full validity range of the model. The reconstructed spectrum does not result in a significant bias or systematic uncertainty in the exemplary physics benchmark process of smuon pair production.
Dynamic spectrum auction in wireless communication
Chen, Yanjiao
2015-01-01
This brief explores current research on dynamic spectrum auctions, focusing on fundamental auction theory, characteristics of the spectrum market, spectrum auction architecture and possible auction mechanisms. The brief explains how dynamic spectrum auctions, which enable new users to gain spectrum access and existing spectrum owners to obtain financial benefits, can greatly improve spectrum efficiency by resolving the artificial spectrum shortage. It examines why operators and users face significant challenges due to specialty of the spectrum market and the related requirements imposed on the auction mechanism design. Concise and up-to-date, Dynamic Spectrum Auction in Wireless Communication is designed for researchers and professionals in computer science or electrical engineering. Students studying networking will also find this brief a valuable resource.
Autism Spectrum Disorders in Iran
Mohammadi, Mohammad Reza; Salmanian, Maryam; AKHONDZADEH, Shahin
2011-01-01
How to Cite this Article: Mohammadi MR, Salmanian M, Akhondzadeh Sh. Autism Spectrum Disorders in Iran. Iranian Journal of Child Neurology2011;5(4):1-9.ObjectiveAutistic disorder, Asperger syndrome, and PDD-Not Otherwise Specified are subsets of autism spectrum disorders (ASDs), which are characterized by impairments in social communication and stereotyped behavior. This article reviews the prevalence, etiology, diagnosis, and treatment of ASDs in Iran.Materials & MethodsWe searched PubMe...
The effect of emotion on movement smoothness during gait in healthy young adults.
Kang, Gu Eon; Gross, M Melissa
2016-12-08
This study aimed to investigate the effect of emotion on movement smoothness during gait. We followed an autobiographical memories paradigm to induce four target emotions, neutral emotion, sadness, anger and joy, in eighteen healthy young adults. Participants performed gait trials while feeling the target emotions. We collected gait data using an eight-camera optoelectronic motion capture system. We measured spatiotemporal gait parameters, smoothness of linear movements for the whole body center-of-mass (COM), head, thorax and pelvis in the anterior-posterior (AP), vertical (VT) and mediolateral (ML) directions, and smoothness of angular movements in the sagittal plane for the shoulder, elbow, wrist, hip, knee and ankle. Movement smoothness was measured as jerk, the first time derivative to acceleration, normalized to movement distance and stride time. Compared to sadness, gait speed increased with anger and joy, and spatiotemporal parameters associated with increased gait speed changed accordingly. In the VT direction, movement smoothness in the whole body COM, head, thorax and pelvis increased for anger and joy compared to sadness. In the AP direction, movement smoothness increased only for the head for neutral emotion, anger and joy compared to sadness. In the ML direction, emotion did not affect movement smoothness. In angular movements, smoothness in the hip and ankle increased for anger compared to sadness. Smoothness in the shoulder increased for anger and joy compared to sadness. The present findings suggest that emotion affects movement smoothness during gait, and that anger and joy are associated with increased movement smoothness. Copyright © 2016 Elsevier Ltd. All rights reserved.
Simulating Magnetized Laboratory Plasmas with Smoothed Particle Hydrodynamics
Energy Technology Data Exchange (ETDEWEB)
Johnson, Jeffrey N. [Univ. of California, Davis, CA (United States)
2009-01-01
The creation of plasmas in the laboratory continues to generate excitement in the physics community. Despite the best efforts of the intrepid plasma diagnostics community, the dynamics of these plasmas remains a difficult challenge to both the theorist and the experimentalist. This dissertation describes the simulation of strongly magnetized laboratory plasmas with Smoothed Particle Hydrodynamics (SPH), a method born of astrophysics but gaining broad support in the engineering community. We describe the mathematical formulation that best characterizes a strongly magnetized plasma under our circumstances of interest, and we review the SPH method and its application to astrophysical plasmas based on research by Phillips [1], Buerve [2], and Price and Monaghan [3]. Some modifications and extensions to this method are necessary to simulate terrestrial plasmas, such as a treatment of magnetic diffusion based on work by Brookshaw [4] and by Atluri [5]; we describe these changes as we turn our attention toward laboratory experiments. Test problems that verify the method are provided throughout the discussion. Finally, we apply our method to the compression of a magnetized plasma performed by the Compact Toroid Injection eXperiment (CTIX) [6] and show that the experimental results support our computed predictions.
SREBP inhibits VEGF expression in human smooth muscle cells.
Motoyama, Koka; Fukumoto, Shinya; Koyama, Hidenori; Emoto, Masanori; Shimano, Hitoshi; Maemura, Koji; Nishizawa, Yoshiki
2006-03-31
Sterol regulatory element-binding proteins (SREBPs) are transcription factors that regulate expression of genes encoding enzymes for lipid biosynthesis. SREBPs are activated by HMG-CoA reductase inhibitors (statins). Statins have been also reported to suppress vascular endothelial growth factor (VEGF) expression in vascular smooth muscle cells (VSMCs). Therefore, we hypothesized that SREBPs are involved in statin-mediated regulation of VEGF production in VSMCs. SREBP1 was robustly expressed, and was activated by atorvastatin in VSMCs, as demonstrated by increased levels of the mature nuclear form of SREBP1, and increased promoter activities of a reporter containing sterol regulatory elements by atorvastatin. Moreover, overexpression of SREBP1a dose-dependently suppressed VEGF promoter activity. Site-specific mutation or deletion of the proximal Sp1 sites reduced the inhibitory effects of SREBP1a on VEGF promoter activity. These data demonstrated that SREBP1, activated by atorvastatin, suppressed VEGF expression through the indirect interaction with the proximal tandem Sp1 sites in VSMCs.
Smooth DNA transport through a narrowed pore geometry.
Carson, Spencer; Wilson, James; Aksimentiev, Aleksei; Wanunu, Meni
2014-11-18
Voltage-driven transport of double-stranded DNA through nanoscale pores holds much potential for applications in quantitative molecular biology and biotechnology, yet the microscopic details of translocation have proven to be challenging to decipher. Earlier experiments showed strong dependence of transport kinetics on pore size: fast regular transport in large pores (> 5 nm diameter), and slower yet heterogeneous transport time distributions in sub-5 nm pores, which imply a large positional uncertainty of the DNA in the pore as a function of the translocation time. In this work, we show that this anomalous transport is a result of DNA self-interaction, a phenomenon that is strictly pore-diameter dependent. We identify a regime in which DNA transport is regular, producing narrow and well-behaved dwell-time distributions that fit a simple drift-diffusion theory. Furthermore, a systematic study of the dependence of dwell time on DNA length reveals a single power-law scaling of 1.37 in the range of 35-20,000 bp. We highlight the resolution of our nanopore device by discriminating via single pulses 100 and 500 bp fragments in a mixture with >98% accuracy. When coupled to an appropriate sequence labeling method, our observation of smooth DNA translocation can pave the way for high-resolution DNA mapping and sizing applications in genomics.
Inflation and Topological Phase Transition Driven by Exotic Smoothness
Directory of Open Access Journals (Sweden)
Torsten Asselmeyer-Maluga
2014-01-01
Full Text Available We will discuss a model which describes the cause of inflation by a topological transition. The guiding principle is the choice of an exotic smoothness structure for the space-time. Here we consider a space-time with topology S3×ℝ. In case of an exotic S3×ℝ, there is a change in the spatial topology from a 3-sphere to a homology 3-sphere which can carry a hyperbolic structure. From the physical point of view, we will discuss the path integral for the Einstein-Hilbert action with respect to a decomposition of the space-time. The inclusion of the boundary terms produces fermionic contributions to the partition function. The expectation value of an area (with respect to some surface shows an exponential increase; that is, we obtain inflationary behavior. We will calculate the amount of this increase to be a topological invariant. Then we will describe this transition by an effective model, the Starobinski or R2 model which is consistent with the current measurement of the Planck satellite. The spectral index and other observables are also calculated.
Effects of Hyperglycemia on Vascular Smooth Muscle Ca2+ Signaling
El-Najjar, Nahed; Kulkarni, Rashmi P.; Nader, Nancy; Hodeify, Rawad
2017-01-01
Diabetes is a complex disease that is characterized with hyperglycemia, dyslipidemia, and insulin resistance. These pathologies are associated with significant cardiovascular implications that affect both the macro- and microvasculature. It is therefore important to understand the effects of various pathologies associated with diabetes on the vasculature. Here we directly test the effects of hyperglycemia on vascular smooth muscle (VSM) Ca2+ signaling in an isolated in vitro system using the A7r5 rat aortic cell line as a model. We find that prolonged exposure of A7r5 cells to hyperglycemia (weeks) is associated with changes to Ca2+ signaling, including most prominently an inhibition of the passive ER Ca2+ leak and the sarcoplasmic reticulum Ca2+-ATPase (SERCA). To translate these findings to the in vivo condition, we used primary VSM cells from normal and diabetic subjects and find that only the inhibition of the ER Ca2+ leaks replicates in cells from diabetic donors. These results show that prolonged hyperglycemia in isolation alters the Ca2+ signaling machinery in VSM cells. However, these alterations are not readily translatable to the whole organism situation where alterations to the Ca2+ signaling machinery are different. PMID:28713824
Dusty gas with one fluid in smoothed particle hydrodynamics
Laibe, Guillaume; Price, Daniel J.
2014-05-01
In a companion paper we have shown how the equations describing gas and dust as two fluids coupled by a drag term can be re-formulated to describe the system as a single-fluid mixture. Here, we present a numerical implementation of the one-fluid dusty gas algorithm using smoothed particle hydrodynamics (SPH). The algorithm preserves the conservation properties of the SPH formalism. In particular, the total gas and dust mass, momentum, angular momentum and energy are all exactly conserved. Shock viscosity and conductivity terms are generalized to handle the two-phase mixture accordingly. The algorithm is benchmarked against a comprehensive suit of problems: DUSTYBOX, DUSTYWAVE, DUSTYSHOCK and DUSTYOSCILL, each of them addressing different properties of the method. We compare the performance of the one-fluid algorithm to the standard two-fluid approach. The one-fluid algorithm is found to solve both of the fundamental limitations of the two-fluid algorithm: it is no longer possible to concentrate dust below the resolution of the gas (they have the same resolution by definition), and the spatial resolution criterion h limitation is that it does not capture multi-streaming of dust in the limit of zero coupling, suggesting that in this case a hybrid approach may be required.
Diet and scavenging habits of the smooth skate Dipturus innominatus.
Forman, J S; Dunn, M R
2012-04-01
The diet of smooth skate Dipturus innominatus was determined from examination of stomach contents of 321 specimens of 29·3-152·0 cm pelvic length, sampled from research and commercial trawlers at depths of 231-789 m on Chatham Rise, New Zealand. The diet was dominated by the benthic decapods Metanephrops challengeri and Munida gracilis, the natant decapod Campylonotus rathbunae and fishes from 17 families, of which hoki Macruronus novaezelandiae, sea perch Helicolenus barathri, various Macrouridae and a variety of discarded fishes were the most important. Multivariate analyses indicated the best predictors of diet variability were D. innominatus length and a spatial model. The diet of small D. innominatus was predominantly small crustaceans, with larger crustaceans, fishes and then scavenged discarded fishes increasing in importance as D. innominatus got larger. Scavenged discards were obvious as fish heads or tails only, or skeletal remains after filleting, often from pelagic species. Demersal fish prey were most frequent on the south and west Chatham Rise, in areas where commercial fishing was most active. Dipturus innominatus are highly vulnerable to overfishing, but discarding practices by commercial fishing vessels may provide a positive feedback to populations through improved scavenging opportunities. © 2012 NIWA. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.
Sparse Recovery using Smoothed $\\ell^0$ (SL0): Convergence Analysis
Mohimani, Hosein; Gorodnitsky, Irina; Jutten, Christian
2010-01-01
Finding the sparse solution of an underdetermined system of linear equations has many applications, especially, it is used in Compressed Sensing (CS), Sparse Component Analysis (SCA), and sparse decomposition of signals on overcomplete dictionaries. We have recently proposed a fast algorithm, called Smoothed $\\ell^0$ (SL0), for this task. Contrary to many other sparse recovery algorithms, SL0 is not based on minimizing the $\\ell^1$ norm, but it tries to directly minimize the $\\ell^0$ norm of the solution. The basic idea of SL0 is optimizing a sequence of certain (continuous) cost functions approximating the $\\ell^0$ norm of a vector. However, in previous papers, we did not provide a complete convergence proof for SL0. In this paper, we study the convergence properties of SL0, and show that under a certain sparsity constraint in terms of Asymmetric Restricted Isometry Property (ARIP), and with a certain choice of parameters, the convergence of SL0 to the sparsest solution is guaranteed. Moreover, we study the ...
Smoothing expansion rate data to reconstruct cosmological matter perturbations
Gonzalez, J. E.; Alcaniz, J. S.; Carvalho, J. C.
2017-08-01
The existing degeneracy between different dark energy and modified gravity cosmologies at the background level may be broken by analyzing quantities at the perturbative level. In this work, we apply a non-parametric smoothing (NPS) method to reconstruct the expansion history of the Universe (H(z)) from model-independent cosmic chronometers and high-z quasar data. Assuming a homogeneous and isotropic flat universe and general relativity (GR) as the gravity theory, we calculate the non-relativistic matter perturbations in the linear regime using the H(z) reconstruction and realistic values of Ωm0 and σ8 from Planck and WMAP-9 collaborations. We find a good agreement between the measurements of the growth rate and fσ8(z) from current large-scale structure observations and the estimates obtained from the reconstruction of the cosmic expansion history. Considering a recently proposed null test for GR using matter perturbations, we also apply the NPS method to reconstruct fσ8(z). For this case, we find a ~ 3σ tension (good agreement) with the standard relativistic cosmology when the Planck (WMAP-9) priors are used.
Simulating deposition of high density tailings using smoothed particle hydrodynamics
Babaoglu, Yagmur; Simms, Paul H.
2017-08-01
Tailings are a slurry of silt-sized residual material derived from the milling of rock. High density (HD) tailings are tailings that have been sufficiently dewatered to a point where they exhibit a yield stress upon deposition. They form gently sloped stacks on the surface when deposited; this eliminates or minimizes the need for dams or embankments for containment. Understanding the flow behaviour of high density tailings is essential for estimating the final stack geometry and overall slope angle. This paper focuses on modelling the flow behaviour of HD tailings using smoothed particle hydrodynamics (SPH) method incorporating a `bi-viscosity' model to simulate the non-Newtonian behaviour. The model is validated by comparing the numerical results with bench scale experiments simulating single or multi-layer deposits in two-dimensions. The results indicate that the model agreed fairly well with the experimental work, excepting some repulsion of particles away from the bottom boundary closer to the toe of the deposits. Novel aspects of the work, compared to other simulation of Bingham fluids by SPH, are the simulation of multilayer deposits and the use of a stopping criteria to characterize the rest state.
Impaired arterial smooth muscle cell vasodilatory function in methamphetamine users.
Nabaei, Ghaemeh; Oveisgharan, Shahram; Ghorbani, Askar; Fatehi, Farzad
2016-11-15
Methamphetamine use is a strong risk factor for stroke. This study was designed to evaluate arterial function and structure in methamphetamine users ultrasonographically. In a cross-sectional study, 20 methamphetamine users and 21 controls, aged between 20 and 40years, were enrolled. Common carotid artery intima-media thickness (CCA-IMT) marker of early atherogenesis, flow-mediated dilatation (FMD) determinants of endothelium-dependent vasodilation, and nitroglycerine-mediated dilatation (NMD) independent marker of vasodilation were measured in two groups. There were no significant differences between the two groups regarding demographic and metabolic characteristics. The mean (±SD) CCA-IMT in methamphetamine users was 0.58±0.09mm, versus 0.59±0.07mm in the controls (p=0.84). Likewise, FMD% was not significantly different between the two groups [7.6±6.1% in methamphetamine users vs. 8.2±5.1% in the controls; p=0.72], nor were peak flow and shear rate after hyperemia. However, NMD% was considerably decreased in the methamphetamine users [8.5±7.8% in methamphetamine users vs. 13.4±6.2% in controls; p=0.03]. According to our results, NMD is reduced among otherwise healthy methamphetamine users, which represents smooth muscle dysfunction in this group. This may contribute to the high risk of stroke among methamphetamine users. Copyright © 2016 Elsevier B.V. All rights reserved.
Noise robust linear dynamic system for phase unwrapping and smoothing.
Estrada, Julio C; Servin, Manuel; Quiroga, Juan A
2011-03-14
Phase unwrapping techniques remove the modulus ambiguities of wrapped phase maps. The present work shows a first-order feedback system for phase unwrapping and smoothing. This system is a fast sequential unwrapping system which also allows filtering some noise because in deed it is an Infinite Impulse Response (IIR) low-pass filter. In other words, our system is capable of low-pass filtering the wrapped phase as the unwrapping process proceeds. We demonstrate the temporal stability of this unwrapping feedback system, as well as its low-pass filtering capabilities. Our system even outperforms the most common and used unwrapping methods that we tested, such as the Flynn's method, the Goldstain's method, and the Ghiglia least-squares method (weighted or unweighted). The comparisons with these methods shows that our system filters-out some noise while preserving the dynamic range of the phase-data. Its application areas may cover: optical metrology, synthetic aperture radar systems, magnetic resonance, and those imaging systems where information is obtained as a demodulated wrapped phase map.
Metal Diffusion in Smoothed Particle Hydrodynamics Simulations of Dwarf Galaxies
Williamson, David; Martel, Hugo; Kawata, Daisuke
2016-05-01
We perform a series of smoothed particle hydrodynamics simulations of isolated dwarf galaxies to compare different metal mixing models. In particular, we examine the role of diffusion in the production of enriched outflows and in determining the metallicity distributions of gas and stars. We investigate different diffusion strengths by changing the pre-factor of the diffusion coefficient, by varying how the diffusion coefficient is calculated from the local velocity distribution, and by varying whether the speed of sound is included as a velocity term. Stronger diffusion produces a tighter [O/Fe]-[Fe/H] distribution in the gas and cuts off the gas metallicity distribution function at lower metallicities. Diffusion suppresses the formation of low-metallicity stars, even with weak diffusion, and also strips metals from enriched outflows. This produces a remarkably tight correlation between “metal mass-loading” (mean metal outflow rate divided by mean metal production rate) and the strength of diffusion, even when the diffusion coefficient is calculated in different ways. The effectiveness of outflows at removing metals from dwarf galaxies and the metal distribution of the gas is thus dependent on the strength of diffusion. By contrast, we show that the metallicities of stars are not strongly dependent on the strength of diffusion, provided that some diffusion is present.
The interaction of otolith organ stimulation and smooth pursuit tracking.
Shelhamer, M; Young, L R
1994-01-01
The interaction of otolith organ stimulation and horizontal pursuit eye tracking in humans was studied in two different paradigms. In the first we measured the effects of lateral linear acceleration on ocular tracking of a retinal after-image, as compared to eye movements produced by acceleration alone (the linear VOR). The second paradigm determined the improvement in smooth oculomotor tracking presumably due to otolith input, by comparing tracking of an earth-fixed target during subject motion to tracking of target motion with the subject stationary. Subject and target motions in each case were sinusoidal. After-image tracking enhanced the gain of the linear VOR by a factor of 2 to 10. This is interpreted to mean that oculomotor efferent copy information is used to reconstruct an internal representation of target velocity, which is then tracked by the oculomotor system in the after-image condition. In the second paradigm, linear motion information transduced by the otolith organs combined with visual target information to yield improved oculomotor tracking over either system alone.
On the role of exponential smoothing in circadian dosimetry.
Price, Luke L A
2014-01-01
The effects lighting has on health through modulation of circadian rhythms are becoming increasingly well documented. Data are still needed to show how light exposures are influenced by architecture and lighting design and circadian dosimetry analyses should provide duration, phase and amplitude measures of 24 h exposure profiles. Exponential smoothing is used to derive suitable metrics from 24 h light measurements collected from private dwellings. A further application of these modified exposure time series as physiological models of the light drive is discussed. Unlike previous light drive models, the dose rate persists into periods of darkness following exposures. Comparisons to long duration exposure studies suggest this type of persistent light drive model could be incorporated into contemporary physiological models of the human circadian oscillator. © 2014 Crown copyright. Photochemistry and Photobiology © 2014 The American Society of Photobiology. This article is published with the permission of the Controller of HMSO and the Queen's Printer for Scotland and Public Health England.
Static and dynamic properties of smoothed dissipative particle dynamics
Alizadehrad, Davod; Fedosov, Dmitry A.
2018-03-01
In this paper, static and dynamic properties of the smoothed dissipative particle dynamics (SDPD) method are investigated. We study the effect of method parameters on SDPD fluid properties, such as structure, speed of sound, and transport coefficients, and show that a proper choice of parameters leads to a well-behaved and accurate fluid model. In particular, the speed of sound, the radial distribution function (RDF), shear-thinning of viscosity, the mean-squared displacement (〈R2 〉 ∝ t), and the Schmidt number (Sc ∼ O (103) - O (104)) can be controlled, such that the model exhibits a fluid-like behavior for a wide range of temperatures in simulations. Furthermore, in addition to the consideration of fluid density variations for fluid compressibility, a more challenging test of incompressibility is performed by considering the Poisson ratio and divergence of velocity field in an elongational flow. Finally, as an example of complex-fluid flow, we present the applicability and validity of the SDPD method with an appropriate choice of parameters for the simulation of cellular blood flow in irregular geometries. In conclusion, the results demonstrate that the SDPD method is able to approximate well a nearly incompressible fluid behavior, which includes hydrodynamic interactions and consistent thermal fluctuations, thereby providing, a powerful approach for simulations of complex mesoscopic systems.
Discussion of Stokes' hypothesis through the smoothed particle hydrodynamics model
Colagrossi, Andrea; Durante, Danilo; Bonet Avalos, Josep; Souto-Iglesias, Antonio
2017-08-01
Stokes' hypothesis, the zeroing of the bulk viscosity in a Newtonian fluid, is discussed in this paper. To this aim, a continuum macroscopic fluid domain is initially modeled as a Hamiltonian system of discrete particles, for which the interparticle dissipative forces are required to be radial in order to conserve the angular momentum. The resulting system of particles is then reconverted to the continuum domain via the framework of the smoothed particle hydrodynamics (SPH) model. Since an SPH-consistent approximation of the Newtonian viscous term in the momentum equation incorporates interparticle radial as well as nonradial terms, it is postulated that the latter must be null. In the present work it is shown that this constraint implies that first and second viscosities are equal, resulting in a positive value for the bulk viscosity, in contradiction to the cited Stokes' hypothesis. Moreover, it is found that this postulate leads to bulk viscosity coefficients close to values found in the experimental literature for monoatomic gases and common liquids such as water.
Numerical Simulation of Solitary Waves Using Smoothed Particle Hydrodynamics Method
Directory of Open Access Journals (Sweden)
Swapnadip De Chowdhury
2012-09-01
Full Text Available Understanding shallow water wave propagation is of major concern in any coastal mitigation effort. Many times, a solitary wave replicates a shallow water wave in its extreme sense which includes a tsunami wave. It is mainly due to known physical characteristics of such waves. Therefore, the study of propagation of solitary waves in the near shore waters is of equal importance in the context of non linear water waves. Owing to the significant growth in computational technologies in the last few decades, a significant number of numerical methods have emerged and applied to simulate nonlinear solitary wave propagation. In this study, one such method, the Smoothed Particle Hydrodynamics (SPH method has been described to simulate the solitary waves. The split-up of a single solitary wave while it crosses a continental kind of shelf has been simulated by the present model. Then SPH model is coupled with the Boussinesq model to predict the time interval between two successive solitary waves on landfall. It has also been shown to be equally efficient in simulating the wave breaking while a solitary wave propagates over a mild slope.
Computing characteristic classes of subschemes of smooth toric varieties
DEFF Research Database (Denmark)
Helmer, Martin
2017-01-01
Let XΣ be a smooth complete toric variety defined by a fan Σ and let V=V(I) be a subscheme of XΣ defined by an ideal I homogeneous with respect to the grading on the total coordinate ring of XΣ. We show a new expression for the Segre class s(V,XΣ) in terms of the projective degrees of a rational...... for the projective degrees of this rational map in terms of the dimension of an explicit quotient ring. Under an additional technical assumption we construct what we call a general dehomogenizing ideal and apply this construction to give effective algorithms to compute the Segre class s(V,XΣ), the Chern......–Schwartz–MacPherson class cSM(V) and the topological Euler characteristic χ(V) of V. These algorithms can, in particular, be used for subschemes of any product of projective spaces Pn1 ×⋯×Pnj or for subschemes of many other projective toric varieties. Running time bounds for several of the algorithms are given...
Epigenetic Control of Smooth Muscle Cell Identity and Lineage Memory.
Gomez, Delphine; Swiatlowska, Pamela; Owens, Gary K
2015-12-01
Vascular smooth muscle cells (SMCs), like all cells, acquire a cell-specific epigenetic signature during development that includes acquisition of a unique repertoire of histone and DNA modifications. These changes are postulated to induce an open chromatin state (referred to as euchromatin) on the repertoire of genes that are expressed in differentiated SMC, including SMC-selective marker genes like Acta2 and Myh11, as well as housekeeping genes expressed by most cell types. In contrast, genes that are silenced in differentiated SMC acquire modifications associated with a closed chromatin state (ie, heterochromatin) and transcriptional silencing. Herein, we review mechanisms that regulate epigenetic control of the differentiated state of SMC. In addition, we identify some of the major limitations in the field and future challenges, including development of innovative new tools and approaches, for performing single-cell epigenetic assays and locus-selective editing of the epigenome that will allow direct studies of the functional role of specific epigenetic controls during development, injury repair, and disease, including major cardiovascular diseases, such as atherosclerosis, hypertension, and microvascular disease, associated with diabetes mellitus. © 2015 American Heart Association, Inc.
Efficient Smoothed Concomitant Lasso Estimation for High Dimensional Regression
Ndiaye, Eugene; Fercoq, Olivier; Gramfort, Alexandre; Leclère, Vincent; Salmon, Joseph
2017-10-01
In high dimensional settings, sparse structures are crucial for efficiency, both in term of memory, computation and performance. It is customary to consider ℓ 1 penalty to enforce sparsity in such scenarios. Sparsity enforcing methods, the Lasso being a canonical example, are popular candidates to address high dimension. For efficiency, they rely on tuning a parameter trading data fitting versus sparsity. For the Lasso theory to hold this tuning parameter should be proportional to the noise level, yet the latter is often unknown in practice. A possible remedy is to jointly optimize over the regression parameter as well as over the noise level. This has been considered under several names in the literature: Scaled-Lasso, Square-root Lasso, Concomitant Lasso estimation for instance, and could be of interest for uncertainty quantification. In this work, after illustrating numerical difficulties for the Concomitant Lasso formulation, we propose a modification we coined Smoothed Concomitant Lasso, aimed at increasing numerical stability. We propose an efficient and accurate solver leading to a computational cost no more expensive than the one for the Lasso. We leverage on standard ingredients behind the success of fast Lasso solvers: a coordinate descent algorithm, combined with safe screening rules to achieve speed efficiency, by eliminating early irrelevant features.
Traction in smooth muscle cells varies with cell spreading
Tolic-Norrelykke, Iva Marija; Wang, Ning
2005-01-01
Changes in cell shape regulate cell growth, differentiation, and apoptosis. It has been suggested that the regulation of cell function by the cell shape is a result of the tension in the cytoskeleton and the distortion of the cell. Here we explore the association between cell-generated mechanical forces and the cell morphology. We hypothesized that the cell contractile force is associated with the degree of cell spreading, in particular with the cell length. We measured traction fields of single human airway smooth muscle cells plated on a polyacrylamide gel, in which fluorescent microbeads were embedded to serve as markers of gel deformation. The traction exerted by the cells at the cell-substrate interface was determined from the measured deformation of the gel. The traction was measured before and after treatment with the contractile agonist histamine, or the relaxing agonist isoproterenol. The relative increase in traction induced by histamine was negatively correlated with the baseline traction. On the contrary, the relative decrease in traction due to isoproterenol was independent of the baseline traction, but it was associated with cell shape: traction decreased more in elongated than in round cells. Maximum cell width, mean cell width, and projected area of the cell were the parameters most tightly coupled to both baseline and histamine-induced traction in this study. Wide and well-spread cells exerted larger traction than slim cells. These results suggest that cell contractility is controlled by cell spreading.
Smoothing spline ANOVA frailty model for recurrent event data.
Du, Pang; Jiang, Yihua; Wang, Yuedong
2011-12-01
Gap time hazard estimation is of particular interest in recurrent event data. This article proposes a fully nonparametric approach for estimating the gap time hazard. Smoothing spline analysis of variance (ANOVA) decompositions are used to model the log gap time hazard as a joint function of gap time and covariates, and general frailty is introduced to account for between-subject heterogeneity and within-subject correlation. We estimate the nonparametric gap time hazard function and parameters in the frailty distribution using a combination of the Newton-Raphson procedure, the stochastic approximation algorithm (SAA), and the Markov chain Monte Carlo (MCMC) method. The convergence of the algorithm is guaranteed by decreasing the step size of parameter update and/or increasing the MCMC sample size along iterations. Model selection procedure is also developed to identify negligible components in a functional ANOVA decomposition of the log gap time hazard. We evaluate the proposed methods with simulation studies and illustrate its use through the analysis of bladder tumor data. © 2011, The International Biometric Society.
Agronomic and chemical evaluation of smooth sumac, Rhus glabra
Energy Technology Data Exchange (ETDEWEB)
Campbell, T.A.
Smooth sumac (Rhus glabra) is a potential whole-plant source of polyphenol and oil. In a 2-yr evaluation of progenies from 14 Maryland, 1 northern Virginia, and 2 Georgia populations, highly significant variation (1% level) in vigor, number of plants surviving the seeding year, dry matter yield the seeding year, and number of tillers produced the second year was observed. In 15 entries, highly significant variation (1% level) in polyphenol + oil and in gallotannins was observed. Dry matter yields, extrapolated to Mg ha/sup -1/, ranged from 0.02 to 1.4 (for a single harvest), % polyphenol + oil from 19.4-31.1, and % gallotannins (a class of polyphenols) from 9.8 to 15.7. It is suggested that significantly improved lines could be developed through breeding. Based on estimated ratios of sigma/sup 2//sub Entries//sigma/sup 2//sub Entries/ + sigma/sup 2/, genetic variation for most agronomic traits could be estimated with fair precision whereas variation for chemical traits could be affected substantially by nongenetic factors. Factor analysis indicated plants that would perform reasonably well over a 2-yr period could be selected on the basis of early seeding-year vigor scores. Selection for high amount of polyphenol + oil and gallotannins would have to be done independently of agronomic selection. Cutting frequencies should not exceed 2 x yr/sup -1/ or serious stand loss would occur.
Impaired Arterial Smooth Muscle Cell Vasodilatory Function In Methamphetamine Users
Directory of Open Access Journals (Sweden)
Ghaemeh Nabaei
2017-02-01
Full Text Available Objectives: Methamphetamine use is a strong risk factor for stroke. This study was designed to evaluate arterial function and structure in methamphetamine users ultrasonographically. Methods: In a cross-sectional study, 20 methamphetamine users and 21 controls, aged between 20 and 40years, were enrolled. Common carotid artery intima-media thickness (CCA-IMT marker of early atherogenesis, flow-mediated dilatation (FMD determinants of endothelium-dependent vasodilation, and nitroglycerine-mediated dilatation (NMD independent marker of vasodilation were measured in two groups. Results: There were no significant differences between the two groups regarding demographic and metabolic characteristics. The mean (±SD CCA-IMT in methamphetamine users was 0.58±0.09mm, versus 0.59±0.07mm in the controls (p=0.84. Likewise, FMD% was not significantly different between the two groups [7.6±6.1% in methamphetamine users vs. 8.2±5.1% in the controls; p=0.72], nor were peak flow and shear rate after hyperemia. However, NMD% was considerably decreased in the methamphetamine users [8.5±7.8% in methamphetamine users vs. 13.4±6.2% in controls; p=0.03]. Conclusion: According to our results, NMD is reduced among otherwise healthy methamphetamine users, which represents smooth muscle dysfunction in this group. This may contribute to the high risk of stroke among methamphetamine users.
Prestretched airway smooth muscle response to length oscillation.
Al-Jumaily, Ahmed M; Roos, Kevin; Bessaguet, Sandy; Jo Avila, Miguel
2017-01-01
Airway smooth muscle (ASM) hyperconstriction is the cause of many respiratory diseases including asthma. In vitro testing has demonstrated that the active forces of ASM are reduced by length oscillation (LO) mimicking tidal breathing. In a previous study, we demonstrated that this force reduction can be further enhanced when superimposing oscillations (with certain frequencies and amplitudes) on this LO In contrast, it has been reported that pressurizing the lung may help in relieving asthmatic airway constrictions. Ultimately, this pressurizing stretches the ASM and may disturb the acto-myosin cross-bridges in a manner similar to LO; however, it is of a static rather than dynamic nature. This research investigates the effect of combining both prestretch- and LO-applications on contracted porcine ASM Isolated porcine ASM relaxation was tested with a 0.56%, 2%, or 4% stretch of its reference length (Lref) in addition to LO These oscillations are composed of a main wave mimicking the normal breathing (frequency of 0.33 Hz and amplitude of 4% Lref) and superimposed oscillations (frequencies of 20, 30, 40, 60 and 80 Hz and amplitude of 1% Lref). The oscillations were maintained for 10 min. The results demonstrate that a prestretch of 0.56% and 2% Lref does enhance the contracted ASM relaxation at certain superimposed length oscillations frequencies while of 4% Lref does not. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.
Determination of adhesion forces between smooth and structured solids
Fischer, Hartmut R.; Gelinck, Edwin R. M.
2012-09-01
Surfaces tend to be made smoother in order to gain flatness or in order to fulfill the need for more precise and reproducible positioning of parts. Adhesion or even sticking of the surfaces is a major showstopper for these applications. There are several measures that can be taken in order to reduce spontaneous adhesion. Quantification of the effectiveness of the chosen solution is most often done using an atomic force microscope (AFM) with probes varying from 1 nm to 8 μm of contact diameter. A serious disadvantage in measuring adhesion by sharp tips is the wear of the tips. Sharp tips wear easily, resulting in undefined contact areas. When the real area of contact is not well defined, the quantification of the adhesion force is not significant. In the current study results of AFM measurements from literature with different tip diameters of colloidal probes are compared with AFM cantilevers with a plateau tip and using probes from large spheres using an alternative setup in combination with a Universal Nano-mechanical Analyzer (UNAT). Test results are shown. Another part of the study deals with a deliberately roughening of smooth surfaces to minimize (spontaneous) adhesion. Good agreement has been found with existing results.
A robust Kalman framework with resampling and optimal smoothing.
Kautz, Thomas; Eskofier, Bjoern M
2015-02-27
The Kalman filter (KF) is an extremely powerful and versatile tool for signal processing that has been applied extensively in various fields. We introduce a novel Kalman-based analysis procedure that encompasses robustness towards outliers, Kalman smoothing and real-time conversion from non-uniformly sampled inputs to a constant output rate. These features have been mostly treated independently, so that not all of their benefits could be exploited at the same time. Here, we present a coherent analysis procedure that combines the aforementioned features and their benefits. To facilitate utilization of the proposed methodology and to ensure optimal performance, we also introduce a procedure to calculate all necessary parameters. Thereby, we substantially expand the versatility of one of the most widely-used filtering approaches, taking full advantage of its most prevalent extensions. The applicability and superior performance of the proposed methods are demonstrated using simulated and real data. The possible areas of applications for the presented analysis procedure range from movement analysis over medical imaging, brain-computer interfaces to robot navigation or meteorological studies.
A Robust Kalman Framework with Resampling and Optimal Smoothing
Directory of Open Access Journals (Sweden)
Thomas Kautz
2015-02-01
Full Text Available The Kalman filter (KF is an extremely powerful and versatile tool for signal processing that has been applied extensively in various fields. We introduce a novel Kalman-based analysis procedure that encompasses robustness towards outliers, Kalman smoothing and real-time conversion from non-uniformly sampled inputs to a constant output rate. These features have been mostly treated independently, so that not all of their benefits could be exploited at the same time. Here, we present a coherent analysis procedure that combines the aforementioned features and their benefits. To facilitate utilization of the proposed methodology and to ensure optimal performance, we also introduce a procedure to calculate all necessary parameters. Thereby, we substantially expand the versatility of one of the most widely-used filtering approaches, taking full advantage of its most prevalent extensions. The applicability and superior performance of the proposed methods are demonstrated using simulated and real data. The possible areas of applications for the presented analysis procedure range from movement analysis over medical imaging, brain-computer interfaces to robot navigation or meteorological studies.
A Method for Low-Delay Pitch Tracking and Smoothing
DEFF Research Database (Denmark)
Christensen, Mads Græsbøll
2012-01-01
In this paper, a new method for pitch tracking is presented. The method is comprised of two steps. In the first step, accurate pitch estimates are obtained on a sample-by-sample basis by updates of the signal statistics with an exponential forgetting factor and subse- quent numerical optimization...... that require fast and sample-by-sample estimates, like tuners for musical instruments, transcription tasks requiring details like vi- brato, and real-time tracking of voiced speech.......In this paper, a new method for pitch tracking is presented. The method is comprised of two steps. In the first step, accurate pitch estimates are obtained on a sample-by-sample basis by updates of the signal statistics with an exponential forgetting factor and subse- quent numerical optimization....... In the second step, a Kalman filter is used to smooth the estimates and separate the pitch into a slowly varying component and a rapidly varying component. The former represents the mean pitch while the latter represents vibrato, slides and other fast changes. The method is intended for use in applica- tions...
van Engelen, E.
2008-01-01
Cervical ripening is a complex process of modification of cervical tissue that enables dilation of the cervix at parturition. Cervical smooth muscle tissue might play a role by contracting or by secretion of cytokines or MMPs. To assess a contractile role for the cervical smooth muscle cells in
Houwen, P.J. van der; Sommeijer, B.P.; Wubs, F.W.
1990-01-01
A smoothing technique for the “preconditioning” of the right-hand side of semidiscrete partial differential equations is analyzed. For a parabolic and a hyperbolic model problem, optimal smoothing matrices are constructed which result in a substantial amplification of the maximal stable integration
van Hoof, H.J.M.; Voss, H.P.; Kramer, K.; Boere, A.J.F.; Dormans, J.A.M.A.; van Bree, L.; Bast, A.
1997-01-01
We studied the effect of in vivo ozone inhalation (3 ppm, 2 h) on neuroreceptor function in guinea pig tracheal smooth muscle in vitro and the role of the epithelial layer in this process. Changes in smooth muscle tension after stimulation of the muscarinic- and β-adrenergic receptor were recorded
Directory of Open Access Journals (Sweden)
Luis Mello
2017-11-01
Full Text Available In this article we study the existence and positions of limit cycles in piecewise smooth perturbations of planar Hamiltonian centers. By using the regularization method we provide an analytical expression for the first order Melnikov function frequently used in the literature directly from the original non-smooth problem.
Vanaverbeke, S.; Keppens, R.; Poedts, S.; Boffin, H.
2009-01-01
We describe the algorithms implemented in the first version of GRADSPH, a parallel, tree-based, smoothed particle hydrodynamics code for simulating self-gravitating astrophysical systems written in FORTRAN 90. The paper presents details on the implementation of the Smoothed Particle Hydro (SPH)
Mast cell numbers in airway smooth muscle and PC(20)AMP in asthma and COPD
Liesker, J. J. W.; ten Hacken, N. H. T.; Rutgers, S. R.; Zeinstra-Smith, M.; Postma, D. S.; Timens, W.
Introduction: Most patients with asthma and many patients with COPD show bronchial hyperresponsiveness to adenosine (BHRAMP). BHRAMP may be caused by release of mast cell histamine, which induces smooth muscle contraction. Aim of the study: To evaluate whether mast cell numbers in airway smooth
Damage Mechanism in Counter Pairs Caused by Bionic Non-smoothed Surface
Directory of Open Access Journals (Sweden)
ZHANG Zhan-hui
2016-08-01
Full Text Available Four biomimetic non-smoothed surface specimens with different shapes were prepared by laser processing. Tests were conducted on MMU-5G wear and abrasion test machine to study the influencing rule of non-smoothed surfaces on counter pairs. The results show that the mass loss of the friction pair matching with the non-smoothed units is much greater than the ones matching with the smooth specimens. The pairs matching with different non-smoothed units suffer differently. The non-smoothed surface protruding zone exerts micro cutting on counter pairs. The striation causes the greatest mass loss of the pairs than the other non-smoothed units, which almost doubles the damage of the grid ones suffering the least. The difference in pairs damage is attributed to the different mechanism of undertaking the load in the process of wear. The damage can be alleviated effectively by changing the shapes of the units without increasing or decreasing the area ratio of the non-smoothed units.
Georgiev, Vladimir; Tarulli, Mirko
2005-01-01
We consider some scale invariant generalizations of the smoothing estimates for the free Schr\\"odnger equation obtained by Kenig, Ponce and Vega. Applying these estimates and using appropriate commutator estimates, we obtain similar scale invariant smoothing estimates for perturbed Schr\\"odnger equation with small magnetic potential.
On the Significance of Demand and Inventory Smoothing Interventions in Supply Chain
Cannella, S.; Ciancimino, E.; Ashayeri, J.
2010-01-01
The aim of this paper is to quantify the benefit of demand and inventory smoothing in contrasting the extreme volatility and impetuous alteration of the market produced by the current economic recession. To do so we model a traditional supply chain and we test five settings of order smoothing under
Wright, D B; Tripathi, S; Sikarwar, A; Santosh, K T; Perez-Zoghbi, J; Ojo, O O; Irechukwu, N; Ward, J P T; Schaafsma, D
Contractile G-protein-coupled receptors (GPCRs) have emerged as key regulators of smooth muscle contraction, both under healthy and diseased conditions. This brief review will discuss some key topics and novel insights regarding GPCR-mediated airway and vascular smooth muscle contraction as
Direct evidence for a position input to the smooth pursuit system.
Blohm, Gunnar; Missal, Marcus; Lefèvre, Philippe
2005-07-01
When objects move in our environment, the orientation of the visual axis in space requires the coordination of two types of eye movements: saccades and smooth pursuit. The principal input to the saccadic system is position error, whereas it is velocity error for the smooth pursuit system. Recently, it has been shown that catch-up saccades to moving targets are triggered and programmed by using velocity error in addition to position error. Here, we show that, when a visual target is flashed during ongoing smooth pursuit, it evokes a smooth eye movement toward the flash. The velocity of this evoked smooth movement is proportional to the position error of the flash; it is neither influenced by the velocity of the ongoing smooth pursuit eye movement nor by the occurrence of a saccade, but the effect is absent if the flash is ignored by the subject. Furthermore, the response started around 85 ms after the flash presentation and decayed with an average time constant of 276 ms. Thus this is the first direct evidence of a position input to the smooth pursuit system. This study shows further evidence for a coupling between saccadic and smooth pursuit systems. It also suggests that there is an interaction between position and velocity error signals in the control of more complex movements.
A three critical point theorem for non-smooth functionals with ...
Indian Academy of Sciences (India)
Abstract. A variety of three-critical-point theorems have been established for non- smooth functionals, based on a minimax inequality. In this paper, a generalized form of a recent result due to Ricceri is introduced for non-smooth functionals and by a few hypotheses, without any minimax inequality, the existence of at least ...
Growth factor-induced contraction of human bronchial smooth muscle is Rho-kinase-dependent
Gosens, Reinout; Schaafsma, D.; Grootte Bromhaar, M.M; Vrugt, B.; Zaagsma, Hans; Meurs, Herman; Nelemans, Herman
2004-01-01
Growth factors have been implicated in the pathophysiology of asthma. However, the putative effects of these growth factors on human airway smooth muscle tone are still largely unknown. We performed contraction experiments using human bronchial smooth muscle ring preparations. The growth factor
Non-linear second-order periodic systems with non-smooth potential
Indian Academy of Sciences (India)
R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22
Abstract. In this paper we study second order non-linear periodic systems driven by the ordinary vector p-Laplacian with a non-smooth, locally Lipschitz potential function. Our approach is variational and it is based on the non-smooth critical point theory. We prove existence and multiplicity results under general growth ...
Non-linear second-order periodic systems with non-smooth potential
Indian Academy of Sciences (India)
In this paper we study second order non-linear periodic systems driven by the ordinary vector -Laplacian with a non-smooth, locally Lipschitz potential function. Our approach is variational and it is based on the non-smooth critical point theory. We prove existence and multiplicity results under general growth conditions on ...
Wijnberg, M.J.; Nieuwenbroek, N.M.E.; Slomp, J.; Quax, P.H.A.; Verheijen, J.H.
1996-01-01
The objective of this study was to investigate the role of the plasminogen activation system in the migration of human vascular smooth muscle cells in vitro. After wounding of confluent human smooth muscle cell cultures by stripping cells from their extracellular matrix, cells start to migrate from
Target Selection by the Frontal Cortex during Coordinated Saccadic and Smooth Pursuit Eye Movements
Srihasam, Krishna; Bullock, Daniel; Grossberg, Stephen
2009-01-01
Oculomotor tracking of moving objects is an important component of visually based cognition and planning. Such tracking is achieved by a combination of saccades and smooth-pursuit eye movements. In particular, the saccadic and smooth-pursuit systems interact to often choose the same target, and to maximize its visibility through time. How do…
A. Tudor (Alexandra)
2010-01-01
textabstractExecutive Summary This study investigates the level of income smoothing and its impact on the informativeness of earnings. The main contribution of this research is that as well IFRS as investor protection are considered to examine the association between income smoothing and earnings