Curvature versus V-bends in a group B titanium T-loop spring

Objective: To compare the system of forces acting on curvature and preactivated V-bends in titanium T-loop springs (TTLSs) made of 0.017- X 0.025-inch TMA (titanium molibdenium alloy) wire.Materials and Methods: Pictures of TTLSs preactivated by curvature and V-bends were inserted in the LOOP software program to design both TTLSs. Symmetry was assured using the program. Both TTLSs used the same amount (length) of wire and had the same angulation between their anterior and posterior extremities when passive. The loops were activated 7 mm, and forces and moments were registered after each 0.5 mm of deactivation. The brackets were at the same height, separated by 23 mm and angulated 0 degrees.Results: The preactivated curvature TTLS delivered horizontal forces ranging from 34 gF to 456 gF, while the TTLS preactivated by V-bends delivered forces ranging from 54 gF to 517 gF. The forces decreased more (30 gF vs 33 gF) with every 0.5 mm of activation on the preactivated V-bend TTLS than on the preactivated curvature TTLS. Vertical forces were low and clinically insignificant for both TTLSs. The moment to force (MF) ratios were systematically higher on the preactivated curvature than on the preactivated V-bend TTLS (from 5.8 mm to 38.8 mm vs 4.7 mm to 28.3 mm).Conclusions: Although both loops show symmetrical moments in their anterior and posterior extremities and can be used for group B anchorage, the curvature preactivated TTLS delivers lower horizontal forces and higher MF ratios than the acute preactivated V-bend TTLS.

Chromosomal evolution in Gekkonidae. I. Chromosome painting between Gekko and Hemidactylus species reveals phylogenetic relationships within the group

Geckos are a large group of lizards characterized by a rich variety of species, different modes of sex determination and diverse karyotypes. In spite of many unresolved questions on lizards' phylogeny and taxonomy, the karyotypes of most geckos have been studied by conventional cytogenetic methods only. We used flow-sorted chromosome-specific painting probes of Japanese gecko (Gekko japonicus), Mediterranean house gecko (Hemidactylus turcicus) and flat-tailed house gecko (Hemidactylus platyurus) to reveal homologous regions and to study karyotype evolution in seven gecko species (Gekko gecko, G. japonicus, G. ulikovskii, G. vittatus, Hemidactylus frenatus, H. platyurus and H. turcicus). Generally, the karyotypes of geckos were found to be conserved, but we revealed some characteristic rearrangements including both fissions and fusions in Hemidactylus. The karyotype of H. platyurus contained a heteromorphic pair in all female individuals, where one of the homologues had a terminal DAPI-negative and C-positive heterochromatic block that might indicate a putative sex chromosome. Among two male individuals studied, only one carried such a polymorphism, and the second one had none, suggesting a possible ZZ/ZW sex determination in some populations of this species. We found that all Gekko species have retained the putative ancestral karyotype, whilst the fission of the largest ancestral chromosome occurred in the ancestor of modern Hemidactylus species. Three common fissions occurred in the ancestor of Mediterranean house and flat-tailed house geckos, suggesting their sister group relationships. PCR-assisted mapping on flow-sorted chromosome libraries with conserved DMRT1 gene primers in G. japonicus indicates the localization of DMRT1 gene on chromosome 6.

Group A T-loop for differential moment mechanics: An implant study

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Escherichia coli phylogenetic group determination and its application in the identification of the major animal source of fecal contamination

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Chromosome analysis in Pseudopaludicola (Anura, Leiuperidae), with description of sex chromosomes XX/XY in P-saltica

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A new species of Galendromus (Acari : Phytoseiidae): A case of intraspecific variation and redefinition of carinulatus species group

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Calcretes of the Bauru Group ( Cretaceous), Brazil; petrology and geological significance.

Reinterprets petrologic studies and their geologic significance in the light of recent literature on the calcretes in the world, and the recent revision of Bauru Group stratigraphy.-from English summary

Adsorption of MX2 (M = Mn, Ni, Cu, Zn, and Cd; X = Cl, Br, and I) and FeCl3 by modified silica surface with imidazolylpropyl group

Silica gel surface modified with imidazolylpropyl group was used to adsorb MX2 (M = Mn, Ni, Cu, Zn, and Cd; X = Cl, Br, and I) and FeCl3 from ethanol and acetone solution. The adsorption capacity and the intensity of the adsorption were determined by using the Langmuir equation. The influences of the solvent, temperature, and degree of functionalization on the adsorption were also studied. The infrared spectra of the functionalized silica were recorded between 1700-1300 cm-1. The bands of the imidazole skeletal vibrations are shifted to higher frequencies upon metal-to-base nitrogen interaction. © 1985.

Some remarks on the conformal group

It is shown that the local isomorphism between the conformal group of Minkowski spacetime and the group SO(4,2) makes sense only if one eliminates from SO(4,2) one of the Sitter boosts contained in it. © 1992.

Molecular genetic maps of the group 6 chromosomes of hexaploid wheat (Triticum aestivum L. em. Thell.)

Restriction fragment length polymorphism (RFLP) maps of chromosomes 6A, 6B, and 6D of hexaploid wheat (Triticum aestivum L. em. Thell.) have been produced. They were constructed using a population of F 7-8 recombinant inbred lines derived from a synthetic wheat X bread wheat cross. The maps consist of 74 markers assigned to map positions at a LOD ≥ 3 (29 markers assigned to 6A, 24 to 6B, and 21 to 6D) and 2 markers assigned to 6D ordered at a LOD of 2.7. Another 78 markers were assigned to intervals on the maps. The maps of 6A, 6B, and 6D span 178, 132, and 206 cM, respectively. Twenty-one clones detected orthologous loci in two homoeologues and 3 detected an orthologous locus in each chromosome. Orthologous loci are located at intervals of from 1.5 to 26 cM throughout 70% of the length of the linkage maps. Within this portion of the maps, colinearity (homosequentiality) among the three homoeologues is strongly indicated. The remainder of the linkage maps consists of three segments ranging in length from 47 to 60 cM. Colinearity among these chromosomes and other Triticeae homoeologous group 6 chromosomes is indicated and a consensus RFLP map derived from maps of the homoeologous group 6 chromosomes of hexaploid wheat, tetraploid wheat, Triticum tauschii, and barley is presented.

Polybitoxins: A group of phospholipases A2 from the venom of the neotropical social wasp paulistinha (Polybia paulista)

The neotropical wasp Polybia paulista is very aggressive and endemic in south-east Brazil, where it frequently causes stinging accidents. By using gel filtration on Sephadex G-200, followed by ion-exchange chromatography on DEAE-Cellulose under a pH gradient, a group of four toxins (designated as polybitoxins-I, II, lII and IV) presenting phospholipase A2 (PLA2) activities was purified. These toxins are dimeric with mol. wts ranging from 115,000 to 132,000 and formed by different subunits. The four toxins contain very high sugar contents attached to their molecules (22-43% w/w) and presented different values of pH optimum from 7.8 to 9.0; when dissociated, only residual catalytic activities were maintained. The catalytic activities of polybitoxins (from 18 to 771 μmoles/mg per minute) are lower than that of PLA2 from Apis mellifera venom and hornetin from Vespa basalis. The polybitoxins presented a non-linear steady-state kinetic behavior for the hydrolysis of phosphatidylcholine at pH 7.9, compatible with the negative co- operativity phenomena. All of the polybitoxins were very potent direct hemolysins, especially the polybitoxins-III and IV, which are as potent as the lethal toxin from V. basalis and hornetin from Vespa flavitarsus, respectively; polybitoxin-IV presented hemolytic action 20 times higher than that of PLA2 from A. mellifera, 17 times higher than that of neutral PLA2 from Naja nigricolis and about 37 times higher than that of cardiotoxin from Naja naja atra venom.

Bacillus thuringiensis development from 1971 to 1996: Cases of a research group in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)