A new titanosaur from western São Paulo State, Upper Cretaceous Bauru Group, south-east Brazil

Material from a new titanosaur from the Bauru Basin (Bauru Group), Brazil is described and compared with well-known titanosaurs. Adamantisaurus mezzalirai gen. et sp. nov. is based on six articulated anterior caudal vertebrae and two haemapophyses collected from the Adamantina Formation, which is considered to be Campanian-Maastrichtian? in age. Adamantisaurus mezzalirai is characterized by the following combination of characteristics: anterior caudal vertebrae with straight or slightly backwardly-projecting neural spines with strongly expanded distal ends, stout prespinal lamina, very wide pre- and postzygapophyseal articular facets, and concave postzygapophyseal articular facets on anterior caudal vertebrae. Although our cladistic analysis has produced equivocal results, Adamantisaurus mezzalirai shares with DGM 'Series B' (Peiropolis titanosaur) and Aeolosaurus the presence of postzygapophyses with concave articular facets, and shares with DGM 'Series B' the presence of laterally expanded neural spines and stout prespinal lamina. Additionally, A. mezzalirai shares with DGM 'Series' C (other titanosaur from Peiropolis) the presence of short neural spines.

Temporal distribution and composition of the ichthyoplankton from Leopoldo's Inlet on the Upper Parana River floodplain (Brazil)

Temporal distribution and composition of ichthyoplankton and their relationships with some environmental variables of Leopoldo's Inlet (Ressaco do Leopoldo) on the upper Parana River floodplain, southern Brazil, were analysed. Samples were taken from February 1991 to February 1992, and 3480 larvae were collected. The highest density of larvae was observed in November 1991 (36.79 larvae/ 10 m(3)) at night (night/day ratio 7: 1). Species composition showed a predominance of Characiformes (80%). There was a high density (4.28 larvae/10 m(3)) of Bryconamericus stramineus throughout almost the whole study period, the majority of the species were more frequently collected at night. Pearson's correlation indicated a relationship between larval density, temperature, and pluviometric index. Leopoldo's Inlet, whose ichthyofauna is mainly composed of grazing and resident species. shows favourable conditions for fish reproduction and development.

Stress analysis of an upper central incisor restored with different posts

The effect of different anatomic shapes and materials of posts in the stress distribution on an endodontically treated incisor was evaluated in this work. This study compared three post shapes (tapered, cylindrical and two-stage cylindrical) made of three different materials (stainless steel, titanium and carbon fibre on Bisphenol A-Glycidyl Methacrylate (Bis-GMA) matrix). Two-dimensional stress analysis was performed using the Finite Element Method. A static load of 100N was applied at 45degrees inclination with respect to the incisor's edge. The stress concentrations did not significantly affect the region adjacent to the alveolar bone crest at the palatine portion of the tooth, regardless of the post shape or material. However, stress concentrations on the post/dentin interface on the palatine side of the tooth root presented significant variations for different post shapes and materials. Post shapes had relatively small impact on the stress concentrations while post materials introduced higher variations on them. Stainless steel posts presented the highest level of stress concentration, followed by titanium and carbon/Bis-GMA posts.

Fluctuating commutative geometry

We use the framework of noncommutative geometry to define a discrete model for fluctuating geometry. Instead of considering ordinary geometry and its metric fluctuations, we consider generalized geometries where topology and dimension can also fluctuate. The model describes the geometry of spaces with a countable number n of points. The spectral principle of Connes and Chamseddine is used to define dynamics. We show that this simple model has two phases. The expectation value , the average number of points in the universe, is finite in one phase and diverges in the other. Moreover, the dimension delta is a dynamical observable in our model, and plays the role of an order parameter. The computation of is discussed and an upper bound is found, < 2. We also address another discrete model defined on a fixed d = 1 dimension, where topology fluctuates. We comment on a possible spontaneous localization of topology.

A 2D coordination polymer with brick-wall network topology based on the [Cu(NCS)(2)(pn)] monomer

The new complex [Cu(NCS)(2)(pn)] (1) (pn = 1,3-propanediamine) has been synthesized and characterized by elemental analysis, infrared and electronic spectroscopy. Single crystal X-ray diffraction studies revealed that complex 1 is made up of neutral [Cu(NCS)(2)(pn)] units which are connected by mu-1,3,3-thiocyanato groups to yield a 2D metal-organic framework with a brick-wall network topology. Intermolecular hydrogen bonds of the type NH...SCN and NH...NCS are also responsible for the stabilization of the crystal structure. (c) 2007 Elsevier B.V. All rights reserved.

Fluctuating dimension in a discrete model for quantum gravity based on the spectral principle

The spectral principle of Connes and Chamseddine is used as a starting point to define a discrete model for Euclidean quantum gravity. Instead of summing over ordinary geometries, we consider the sum over generalized geometries where topology, metric, and dimension can fluctuate. The model describes the geometry of spaces with a countable number n of points, and is related to the Gaussian unitary ensemble of Hermitian matrices. We show that this simple model has two phases. The expectation value , the average number of points in the Universe, is finite in one phase and diverges in the other. We compute the critical point as well as the critical exponent of . Moreover, the space-time dimension delta is a dynamical observable in our model, and plays the role of an order parameter. The computation of is discussed and an upper bound is found, < 2.

BERRY PHASE, AHARONOV-BOHM EFFECT AND TOPOLOGY

The Berry phase for an electron in a one-dimensional box rotated around a magnetic flux line has contributions from the geometry and the magnetic flux, which gives an Aharonov-Bohm effect. For a circular box enclosing the magnetic flux, the Berry phase depends on the boundary conditions.

Effects of self-assembly process of latex spheres on the final topology of macroporous silica

This paper surveys the topology of macroporous silica prepared using latex templates covering the submicrometric range (0.1-0.7 mu m). The behavior of latex spheres in aqueous dispersion has been analyzed by dynamic light scattering (DLS) measurement indicating the most appropriate conditions to form well-defined cubic arrays. The optical behavior of latex spheres has been analyzed by transmittance and reflectance measurements in order to determine their diameter and filling factor when they were assembled in bidimensional arrays. Macroscopic templates have been obtained by a centrifugation process and their crystalline ordering has been confirmed by porosimetry and scanning electron microscopy. These self-assembled structures have been used to produce macroporous silica, whose final topology depends on the pore size distribution of the original template. It has been seen that latex spheres are ordered in a predominant fcc arrangement with slipping of tetragonal pores due to the action of attractive electrostatic interactions. The main effect is to change the spherical shape of voids in macroporous silica into a hexagonal configuration with possible applications to fabricate photonic devices with novel optical properties. (c) 2005 Elsevier B.V. All rights reserved.

CROCODYLOMORPH EGGS and EGGSHELLS FROM THE ADAMANTINA FORMATION (BAURU GROUP), UPPER CRETACEOUS of BRAZIL

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Density functional theory study on the structural and electronic properties of low index rutile surfaces for TiO2/SnO2/TiO2 and SnO2/TiO2/SnO2 composite systems

The present study is concerned with the structural and electronic properties of the TiO2/SnO2/TiO2 and SnO2/TiO2/SnO2 composite systems. Periodic quantum mechanical method with density functional theory at the B3LYP level has been carried out. Relaxed surface energies, structural characteristics and electronic properties of the (I 10), (0 10), (10 1) and (00) low-index rutile surfaces for TiO2/SnO2/TiO2 and SnO2/TiO2/SnO2 models are studied. For, comparison purposes, the bare rutile TiO2 and SnO2 structures are also analyzed and compared with previous theoretical and experimental data. The calculated surface energy for both rutile TiO2 and SnO2 surfaces follows the sequence (110) < (010) < (101) < (001) and the energy increases as (010) < (101) < (110) < (001) and (010) approximate to (110) < (101) < (001) for SnO2/TiO2/SnO2 and TiO2/SnO2/TiO2 composite systems, respectively. SnO2/TiO2/SnO2 presents larger values of surface energy than the individual SnO2 and TiO2 metal oxides and the TiO2/SnO2/TiO2 system renders surface energy values of the same order that the TiO2 and lower than the SnO2. An analysis of the electronic structure of the TiO2/SnO2/TiO2 and SnO2/TiO2/SnO2 systems shows that the main characteristics of the upper part of the valence bands for all the studied surfaces are dominated by the external layers, i.e., by the TiO2 and the SnO2, respectively, and the topology of the lower part of the conduction bands looks like the core layers. There is an energy stabilization of both valence band top and conduction band bottom for (110) and (010) surfaces of the SnO2/TiO2/SnO2 composite system in relation to their core TiO2, whereas an opposite trend is found for the same surfaces of the TiO2/SnO2/TiO2 composite system in relation to the bare SnO2. The present theoretical results may explain the growth of TiO2@SnO2 bimorph composite nanotape.

A new specimen of Stratiotosuchus maxhechti (Baurusuchidae, Crocodyliformes) from the Adamantina Formation (Upper Cretaceous), southeastern Brazil.

This is a report about the second occurrence and description of the third specimen of Stratiotosuchus maxhechti (Baurusuchidae, Crocodyliformes) from the Bauru Basin, Upper Cretaceous of southeastern Brazil. The material was found in the typical reddish, fine-grained sandstone from the Adamantina Formation, Bauru Group, Monte Alto County, São Paulo State. These strata are considered to be Campanian-Maastrichtian in age. It is the second skull of Stratiotosuchus maxhechti recovered where the choanal region and the skull-mandible articulation is preserved. The holotype of this species comes from the Adamantina Formation from southwestern São Paulo State, while this new specimen comes from its northern-central region, making possible biocbronological and paleoccological correlations among different geographically distant stratigraphic horizons within the Bauru Basin. The main osteologic contributions from this new specimen are the surangular taking part in the skull/mandible articulation and the presence of a relatively well-preserved choanal region, which are not seen in the holotype, furthering the knowledge of Stratiotosuchus maxhechti. Based on the features of this new specimen, an emended diagnosis is provided.

Three new species of Neoplecostomus (Teleostei: Siluriformes: Loricariidae) from the Upper Rio Parana basin of southeastern Brazil

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