A Boolean algebra and a Banach space obtained by push-out iteration

Under the assumption that c is a regular cardinal, we prove the existence and uniqueness of a Boolean algebra B of size c defined by sharing the main structural properties that P(omega)/fin has under CH and in the N(2)-Cohen model. We prove a similar result in the category of Banach spaces. (C) 2011 Elsevier B.V. All rights reserved.

Adenosine receptor type 2a is differently modulated by nicotine in dorsal brainstem cells of Wistar Kyoto and spontaneously hypertensive rats

Hypertension can result from neuronal network imbalance in areas of central nervous system that control blood pressure, such as the nucleus tractus solitarius (NTS). There are several neurotransmitters and neuromodulatory substances within the NTS, such as adenosine, which acts on purinoreceptors A(2a) (A(2a)R). The A(2a)R modulates neurotransmission in the NTS where its activation may induce decrease in blood pressure by different mechanisms. Nicotine is a molecule that crosses the hematoencephalic barrier and acts in several areas of central nervous system including the NTS, where it may interact with some neurotransmitter systems and contributes to the development of hypertension in subjects with genetic predisposition to this disease. In this study we first determined A(2a)R binding, protein, and mRNA expression in dorsomedial medulla oblongata of neonate normotensive (WKY) and spontaneously hypertensive rats (SHR). Subsequently, we analyzed the modulatory effects of nicotine on A(2a)R in cell culture in order to evaluate its possible involvement in the development of hypertension. Data showed a decreased A(2a)R binding and increased protein and mRNA expression in tissue sample and culture of dorsal brainstem from SHR compared with those from WKY rats at basal conditions. Moreover, nicotine modulated A(2a)R binding, protein, and mRNA expression in cells from both strains. Interestingly, nicotine decreased A(2a)R binding and increased protein levels, as well as, induced a differential modulation in A(2a)R mRNA expression. Results give us a clue about the mechanisms involved in the modulatory effects of nicotine on A(2a)R as well as hypothesize its possible contribution to the development of hypertension. In conclusion, we demonstrated that A(2a)R of SHR cells which differ from WKY and nicotine differentially modulates A(2a)R in dorsal brainstem cells of SHR and WKY.

Effect of meloxicam and diclofenac sodium on peri-implant bone healing in rats

Background: This study evaluated the effects of diclofenac sodium and meloxicam on peri-implant bone healing. Methods: Thirty male rats were divided into three groups: the control group (CG) received no drug; the diclofenac sodium group (DSG) received 1.07 mg/kg twice a day for 5 days; and the meloxicam group (MG) received 0.2 mg/kg daily for 5 days. A screw-shaped titanium implant was placed in the tibia. Fluorochromes, oxytetracycline (OxT), calcein (CA), and alizarin (AL), were injected at 7, 14, and 21 days, respectively, after implantation, and the animals were sacrificed 28 days after implant placement. The percentages of OxT-, CA-, and AL-labeled bone as well as the percentages of bone-to-implant contact (BIC), cortical bone area (CBA), and trabecular bone area (TBA) within the implant threads were evaluated. Results: Bone healing was delayed in the DSG during the first 14 days after implant placement (OxT-labeled bone: DSG: 5.3% +/- 7.3% versus CG: 13.2% +/- 9.8%, P= 0.002, and versus MG: 14.4% +/- 13.1%, P = 0.05). The percentages of BIC (DSG: 49.6% +/- 21.9%; MG: 67.1% +/- 22.8%; and CG: 68.1% +/- 22.8%) and CBA (DSG: 63.7% +/- 21.2%; MG: 82.7% +/- 12.4%; CG: 84.9% +/- 10.6%) were lower in the DSG compared to the MG and CG (P<0.001). The percentage of TBA was significantly greater in the DSG compared to the MG and CG (DSG: 36.3% +/- 21.2% versus MG: 17.3% +/- 12.7% and versus CG: 15.1% +/- 10.6%; P<0.001). Conclusion: Diclofenac sodium seemed to delay peri-implant bone healing and to decrease BIC, whereas meloxicam had no negative effect on peri-implant bone healing.

Differential response of AMPA and NMDA glutamate receptors of Purkinje cells to aging of the chicken cerebellum

Aging can lead to cognitive, affective, learning, memory and motor deficits. Since the cerebellum and glutamatergic neurotransmission are involved in several of those functions, the present work aimed at studying the expression of AMPA and NMDA glutamate receptor subunits in the chick cerebellum during aging. Young (30 days old) and aged (ca. 4 years old) chickens (Gallus gallus) were used in order to evaluate the expression of GluR1, GluR2/3 and NR1 subunits. The cerebella of young and aged chickens were subjected to immunohistochemical and immunoblotting techniques. Numbers of GluR1, GluR2/3 and NR1-positive cells and optical density of the immunoblotting data were analyzed and submitted to statistical analysis using ANOVA and the Bonferroni post hoc test. Mean density of Purkinje cells stained for Giemsa, GluR1, GluR2/3 and NR1 in the cerebellum all showed a statistically significant decrease in aged animals when compared to the young animals (Giemsa, P < 0.01; GluRs and NR1, P < 0.03). However, the ratio of GluR1 and GluR2/3-positive Purkinje cells in relation the total number of Purkinje cells found in each time point decreased with aging (ca. 10%), whereas the ratio of NR1-positive cells increased (ca. 9%). The immunoblotting data showed a significant decrease of GluR1 (ca. 66%) and GluR2/3 (ca. 55%) protein expression with aging, but did not reveal changes for NR1. Our data suggest that aging can lead to differential changes in the pattern of expression of glutamate receptor subunits, which can underlie at least part of the cognitive and motor disorders found in aged animals. (c) 2010 Elsevier Ireland Ltd. All rights reserved.

Positive solutions for a fourth order equation with nonlinear boundary conditions

Existence of positive solutions for a fourth order equation with nonlinear boundary conditions, which models deformations of beams on elastic supports, is considered using fixed points theorems in cones of ordered Banach spaces. Iterative and numerical solutions are also considered. (C) 2010 IMACS. Published by Elsevier B.V. All rights reserved.

Averaging for retarded functional differential equations

We consider retarded functional differential equations in the setting of Kurzweil-Henstock integrable functions and we state an averaging result for these equations. Our result generalizes previous ones. (C) 2011 Elsevier Inc. All rights reserved.

Static Hopfions in the extended Skyrme-Faddeev model

We construct static soliton solutions with non-zero Hopf topological charges to a theory which is an extension of the Skyrme-Faddeev model by the addition of a further quartic term in derivatives. We use an axially symmetric ansatz based on toroidal coordinates, and solve the resulting two coupled non-linear partial differential equations in two variables by a successive over-relaxation (SOR) method. We construct numerical solutions with Hopf charge up to four, and calculate their analytical behavior in some limiting cases. The solutions present an interesting behavior under the changes of a special combination of the coupling constants of the quartic terms. Their energies and sizes tend to zero as that combination approaches a particular special value. We calculate the equivalent of the Vakulenko and Kapitanskii energy bound for the theory and find that it vanishes at that same special value of the coupling constants. In addition, the model presents an integrable sector with an in finite number of local conserved currents which apparently are not related to symmetries of the action. In the intersection of those two special sectors the theory possesses exact vortex solutions (static and time dependent) which were constructed in a previous paper by one of the authors. It is believed that such model describes some aspects of the low energy limit of the pure SU(2) Yang-Mills theory, and our results may be important in identifying important structures in that strong coupling regime.

Axially symmetric soliton solutions in a Skyrme-Faddeev-type model with Gies`s extension

We construct static soliton solutions with non-zero Hopf topological charges to a theory which is the extended Skyrme-Faddeev model with a further quartic term in derivatives. We use an axially symmetric ansatz based on toroidal coordinates, and solve the resulting two coupled nonlinear partial differential equations in two variables by a successive over-relaxation method. We construct numerical solutions with the Hopf charge up to 4. The solutions present an interesting behavior under the changes of a special combination of the coupling constants of the quartic terms.

ALGEBRAIC AND GEOMETRIC THEORY OF THE TOPOLOGICAL RING OF COLOMBEAU GENERALIZED FUNCTIONS

We continue the investigation of the algebraic and topological structure of the algebra of Colombeau generalized functions with the aim of building up the algebraic basis for the theory of these functions. This was started in a previous work of Aragona and Juriaans, where the algebraic and topological structure of the Colombeau generalized numbers were studied. Here, among other important things, we determine completely the minimal primes of (K) over bar and introduce several invariants of the ideals of 9(Q). The main tools we use are the algebraic results obtained by Aragona and Juriaans and the theory of differential calculus on generalized manifolds developed by Aragona and co-workers. The main achievement of the differential calculus is that all classical objects, such as distributions, become Cl-functions. Our purpose is to build an independent and intrinsic theory for Colombeau generalized functions and place them in a wider context.

Spaces of compact operators on C(2(m) circle plus [0, alpha]) spaces

We classify up to isomorphism the spaces of compact operators K(E, F), where E and F are Banach spaces of all continuous functions defined on the compact spaces 2(m) circle plus [0, alpha], the topological sum of Cantor cubes 2(m) and the intervals of ordinal numbers [0, alpha]. More precisely, we prove that if 2(m) and aleph(gamma) are not real-valued measurable cardinals and n >= aleph(0) is not sequential cardinal, then for every ordinals xi, eta, lambda and mu with xi >= omega(1), eta >= omega(1), lambda = mu < omega or lambda, mu is an element of [omega(gamma), omega(gamma+1)[, the following statements are equivalent: (a) K(C(2(m) circle plus [0, lambda]), C(2(n) circle plus [0, xi])) and K(C(2(m) circle plus [0, mu]), C(2(n) circle plus [0, eta]) are isomorphic. (b) Either C([0, xi]) is isomorphic to C([0, eta] or C([0, xi]) is isomorphic to C([0, alpha p]) and C([0, eta]) is isomorphic to C([0,alpha q]) for some regular cardinal alpha and finite ordinals p not equal q. Thus, it is relatively consistent with ZFC that this result furnishes a complete isomorphic classification of these spaces of compact operators. (C) 2010 Elsevier Inc. All rights reserved.

UNIFORM APPROXIMATION ON IDEALS OF MULTILINEAR MAPPINGS

For each ideal of multilinear mappings M we explicitly construct a corresponding ideal (a)M such that multilinear forms in (a)M are exactly those which can be approximated, in the uniform norm, by multilinear forms in M. This construction is then applied to finite type, compact, weakly compact and absolutely summing multilinear mappings. It is also proved that the correspondence M bar right arrow (a)M. IS Aron-Berner stability preserving.

Role of sigma(54) in the regulation of genes involved in type I and type IV pili biogenesis in Xylella fastidiosa

The phytopathogen Xylella fastidiosa produces long type IV pili and short type I pili involved in motility and adhesion. In this work, we have investigated the role of sigma factor sigma(54) (RpoN) in the regulation of fimbrial biogenesis in X. fastidiosa. An rpoN null mutant was constructed from the non-pathogenic citrus strain J1a12, and microarray analyses of global gene expression comparing the wild type and rpoN mutant strains showed few genes exhibiting differential expression. In particular, gene pilA1 (XF2542), which encodes the structural pilin protein of type IV pili, showed decreased expression in the rpoN mutant, whereas two-fold higher expression of an operon encoding proteins of type I pili was detected, as confirmed by quantitative RT-PCR (qRT-PCR) analysis. The transcriptional start site of pilA1 was determined by primer extension, downstream of a sigma(54)-dependent promoter. Microarray and qRT-PCR data demonstrated that expression of only one of the five pilA paralogues, pilA1, was significantly reduced in the rpoN mutant. The rpoN mutant made more biofilm than the wild type strain and presented a cell-cell aggregative phenotype. These results indicate that sigma(54) differentially regulates genes involved in type IV and type I fimbrial biogenesis, and is involved in biofilm formation in X. fastidiosa.

High Matrix Metalloproteinase Activity Is a Hallmark of Periapical Granulomas

Introduction: The inability to distinguish periapical cysts from granulomas before performing root canal treatment leads to uncertainty in treatment outcomes because cysts have lower healing rates. Searching for differential expression of molecules within cysts or granulomas could provide information with regard to the identity of the lesion or suggest mechanistic differences that may form the basis for future therapeutic intervention. Thus, we investigated whether granulomas and cysts exhibit differential expression of extracellular matrix (ECM) molecules. Methods: Human periapical granulomas, periapical cysts, and healthy periodontal ligament tissues were used to investigate the differential expression of ECM molecules by microarray analysis. Because matrix metalloproteinases (MMP) showed the highest differential expression in the microarray analysis, MMPs were further examined by in situ zymography and immunohistochemistry. Data were analyzed by using one-way analysis of variance followed by the Tu-key test. Results: We observed that cysts and granulomas differentially expressed several ECM molecules, especially those from the MMP family. Compared with cysts, granulomas exhibited higher MMP enzymatic activity in areas stained for MMP-9. These areas were composed of polymorphonuclear cells (PMNs) in contrast to cysts. Similarly, MMP-13 was expressed by a greater number of cells in granulomas compared with cysts. Conclusion: Our findings indicate that high enzymatic MIMP activity in PMNs together with MMP-9 and MMP-13 stained cells could be a molecular signature of granulomas unlike periapical cysts. (J Endod 2009;35:1234-1242)

CONSTRUCTING QUANTUM OBSERVABLES AND SELF-ADJOINT EXTENSIONS OF SYMMETRIC OPERATORS. III. SELF-ADJOINT BOUNDARY CONDITIONS

This paper completes the review of the theory of self-adjoint extensions of symmetric operators for physicists as a basis for constructing quantum-mechanical observables. It contains a comparative presentation of the well-known methods and a newly proposed method for constructing ordinary self-adjoint differential operators associated with self-adjoint differential expressions in terms of self-adjoint boundary conditions. The new method has the advantage that it does not require explicitly evaluating deficient subspaces and deficiency indices (these latter are determined in passing) and that boundary conditions are of explicit character irrespective of the singularity of a differential expression. General assertions and constructions are illustrated by examples of well-known quantum-mechanical operators like momentum and Hamiltonian.

Contribution of SHRIMP U-Pb zircon geochronology to unravelling the evolution of Brazilian Neoproterozoic fold belts

The South-American continent is constituted of three major geologic-geotectonic entities the homonym platform (consolidated at the end of the Cambrian) the Andean chain (essentially Meso-Cenozoic) and the Patagonian terrains affected by tectonism and magmatism through almost all of the Phanerozoic The platform is constituted by a series of cratonic nuclei (pre-Tonian fragments of the Rodinia fission) surrounded by a complex fabric of Neoproterozoic structural provinces Two major groups of orogenic processes (plate interaction cycles) constitute the evolution of these provinces the older occurred in the Tonian (smaller in area) and the younger Brasiliano that is present in all provinces The Tonian cycles (pre-Rodinia fission?) are still being sorted out and many questions still need to be answered The Brasiliano orogenic collage events (post-Rodinia fission?) developed in three main stages in part coeval from a province to another and are 650-600 580-560 and 540-500 Ma respectively (the late event reaching the Ordovician) The first group of orogenies is recorded in practically all provinces The third group is restricted to part of the Mantiqueira Province (southeast of the platform Buzios Orogeny) and present in the Pampean province (SW of the platform) For all these groups of orogenic events there are considerable records of rock assemblages related to processes of convergent plate interaction opening accretion collision and further extrusion There is a good correlation between the geologic and geotectonic data and geochemical and isotopic data The late tectonic processes (post-orogenic magmatism foreland basins etc) of the first two groups compete in time in distinct spaces with the peak of orogenic processes in the third group The introduction of the SHRIMP U-Pb methodology was fundamental to separate the Tonian and post-Tonian orogenic groups and their respective divisions in time and space Thus there are still many open points/problems which lead to expectations of addressing these issues in the near future with the more Intense use of this methodology (C) 2010 Elsevier B V All rights reserved