743 research outputs found
Nontrivial classes in from nontrivalent graph cocycles
We construct nontrivial cohomology classes of the space of
imbeddings of the circle into , by means of Feynman diagrams. More
precisely, starting from a suitable linear combination of nontrivalent
diagrams, we construct, for every even number , a de Rham cohomology
class on . We prove nontriviality of these classes by evaluation
on the dual cycles.Comment: 10 pages, 11 figures. V2: minor changes, typos correcte
Restauración y puesta en valor de esculturas metálicas
Las esculturas en metal pueden permanecer al exterior durante un cierto tiempo que dependerá de su composición y del grado de ataque ambiental, siendo necesarios su mantenimiento y reparaciones a lo largo de su vida útil.
En este trabajo se presentan estudios y recomendaciones para la recuperación de las esculturas de metal fundido, de alto valor artístico y urbanístico, pero expuestas a daños atmosféricos y roturas por maltrato, ubicadas en espacio público urbano
The homotopy invariance of the string topology loop product and string bracket
Let M be a closed, oriented, n -manifold, and LM its free loop space.
Chas and Sullivan defined a commutative algebra structure in the homology of
LM, and a Lie algebra structure in its equivariant homology. These structures
are known as the string topology loop product and string bracket, respectively.
In this paper we prove that these structures are homotopy invariants in the
following sense.
Let f : M_1 \to M_2 be a homotopy equivalence of closed, oriented n
-manifolds. Then the induced equivalence, Lf : LM_1 \to LM_2 induces a ring
isomorphism in homology, and an isomorphism of Lie algebras in equivariant
homology. The analogous statement also holds true for any generalized homology
theory h_* that supports an orientation of the M_i 's.Comment: 21 pages, 2 figures final version published in Journal of Topolog
Design and Tests of the Silicon Sensors for the ZEUS Micro Vertex Detector
To fully exploit the HERA-II upgrade,the ZEUS experiment has installed a
Micro Vertex Detector (MVD) using n-type, single-sided, silicon micro-strip
sensors with capacitive charge division. The sensors have a readout pitch of
120 micrometers, with five intermediate strips (20 micrometer strip pitch). The
designs of the silicon sensors and of the test structures used to verify the
technological parameters, are presented. Results on the electrical measurements
are discussed. A total of 1123 sensors with three different geometries have
been produced by Hamamatsu Photonics K.K. Irradiation tests with reactor
neutrons and Co-60 photons have been performed for a small sample of sensors.
The results on neutron irradiation (with a fluence of 1 x 10^{13} 1 MeV
equivalent neutrons / cm^2) are well described by empirical formulae for bulk
damage. The Co-60 photons (with doses up to 2.9 kGy) show the presence of
generation currents in the SiO_2-Si interface, a large shift of the flatband
voltage and a decrease of the hole mobility.Comment: 33 pages, 25 figures, 3 tables, accepted for publication in NIM
Expression study of receptor tyrosine kinase targets of Imatinib mesylate in skull base chordomas
Chordomas are rare neoplasms arising along the axial skeleton. Up to now, the most suitable therapeutic approach is based on a combination of surgical excision and radiotherapy. Chemotherapy in not applied due to its reported low efficacy. Recently, evidence on the efficacy of Imatinib mesylate in two patients has been reported. We analyzed 14 chordoma samples for the expression of the Imatinib mesylate targets by means of RT-PCR and immunohistochemistry and found that PDGFR\u3b1 and PDGFR\u3b2 are in some cases expressed in neoplastic cells, while the stromal counterpart of the same tumor shows the above receptors. Findings on the PDGFA/PDGFB expression suggest a receptor-activated status. Our study provides new insights into the specific localization of Imatinib mesylate targets in skull base chordomas that could be taken into account for the setting up of a pharmacological treatment for this tumor
Self-ligating versus conventional metallic brackets on Streptococcus mutans retention:A systematic review
ABSTRACT
Objective: The present study aimed to review the literature systematically and assess comparatively whether self-ligating metallic brackets accumulate less Streptococcus mutans biofilm than conventional metallic brackets. Material and methods: The systematic search was performed following PRISMA guidelines and registration in PROSPERO. Seven electronic databases (Google Scholar, LILACS, Open Grey, PubMed, SciELO, ScienceDirect, and Scopus) were consulted until April 2016, with no restriction of language and time of publication. Only randomized clinical studies verifying S. mutans colonization in metallic brackets (self-ligating and conventional) were included. All steps were performed independently by two operators. Results: The search resulted in 546 records obtained from the electronic databases. Additionally, 216 references obtained from the manual search of eligible articles were assessed. Finally, a total of 5 studies were included in the qualitative synthesis. In 1 study, the total bacterial count was not different among self-ligating and conventional brackets, whereas in 2 studies the amount was lower for self-ligating brackets. Regarding the specific count of S. mutans, 2 studies showed less accumulation in self-ligating than in conventional brackets. Conclusion: Based on the limited evidence, self-ligating metallic brackets accumulate less S. mutans than conventional ones. However, these findings must be interpreted in conjunction with particularities individual for each patient – such as hygiene and dietary habits, which are components of the multifactorial environment that enables S. Mutans to proliferate and keep retained in the oral cavity.</jats:p
Editorial: Advances in biofabrication for skin regeneration
info:eu-repo/semantics/publishedVersio
Hypercalciuria and nephrolithiasis: Expanding the renal phenotype of Donnai-Barrow syndrome
Whole exome sequencing detected novel likely pathogenic variants in LRP2 gene in 2 patients presenting with hearing and vision loss, and the Dent disease (DD) classical renal phenotype, that is, low molecular weight proteinuria (LMWP), hypercalciuria and nephrocalcinosis/nephrolithiasis. We propose that a subset of patients presenting as DD may represent unrecognized cases or mild forms of Donnai-Barrow/facio-oculo-acustico-renal (DB/FOAR) syndrome or be on the phenotypic continuum between the 2 conditions
Caracterización físico-química de ambientes acuáticos permanentes y temporarios del Chaco Oriental
Physico-chemical characteristies of 17 strearas and 3 tropical swamps-so called "esteros"- were studied in the provinces of Santa Fe, Chaco and Formosa in the esastern Chaco (Argentine). This study was done in order to gather suitable information about the availability of regional hydric re-sources, to determine the possible utilization and to contribute to the improvement of the landscape management.
In the initial stage, samples were analyzed in three different opportunities during the hydrologic cycle, including dry and flooded seasons.
The paper describes seasonal variations of the salinity, major ion composition, expressed as the porcentage of equivalent sum of total cations or anions, their geographical distribution and some other features, as the nutrient levels,hardness and aptitude for irrigation. On this basis, a characterization of the differents habitats is given also considering the most distinctive physico-chemical features.
Analysis have been made according with the methodology described in Standard Methods (APHA, 1975) and Golterman and Clymo (IBP, 1978).
Among the obtained records, the most relevant was the one concerning with the salinization phenomena being frequent in the Salado, Saladito, Saladillo and Palometa streams. In low water periods, they increased the conductivity to 103 uS.cm-1, with the correlative increment in the sodium, chloride and sulfate concentration which determined changes in the ionic typology.Physico-chemical characteristies of 17 strearas and 3 tropical swamps-so called "esteros"- were studied in the provinces of Santa Fe, Chaco and Formosa in the esastern Chaco (Argentine). This study was done in order to gather suitable information about the availability of regional hydric re-sources, to determine the possible utilization and to contribute to the improvement of the landscape management.
In the initial stage, samples were analyzed in three different opportunities during the hydrologic cycle, including dry and flooded seasons.
The paper describes seasonal variations of the salinity, major ion composition, expressed as the porcentage of equivalent sum of total cations or anions, their geographical distribution and some other features, as the nutrient levels,hardness and aptitude for irrigation. On this basis, a characterization of the differents habitats is given also considering the most distinctive physico-chemical features.
Analysis have been made according with the methodology described in Standard Methods (APHA, 1975) and Golterman and Clymo (IBP, 1978).
Among the obtained records, the most relevant was the one concerning with the salinization phenomena being frequent in the Salado, Saladito, Saladillo and Palometa streams. In low water periods, they increased the conductivity to 103 uS.cm-1, with the correlative increment in the sodium, chloride and sulfate concentration which determined changes in the ionic typology
Absence of acquired copy number neutral loss of heterozygosity (CN-LOH) of chromosome 7 in a series of 10 patients with Shwachman-Diamond syndrome
We report that acquired copy number neutral loss of heterozygosity (CN-LOH) of chromosome 7 was not identified in a series of 10 patients with Shwachman\u2013Diamond syndrome (SDS)
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