Classification of seed storage behaviour of 67 Amazonian tree species

Information was collated on the seed storage behaviour of 67 tree species native to the Amazon rainforest of Brazil; 38 appeared to show orthodox, 23 recalcitrant and six intermediate seed storage behaviour. A double-criteria key based on thousand-seed weight and seed moisture content at shedding to estimate likely seed storage behaviour, developed previously, showed good agreement with the above classifications. The key can aid seed storage behaviour identification considerably.

Chemistry and structure by design: ordered CuNi(CN)4 sheets with copper(II) in a square-planar environment

Layered copper–nickel cyanide, CuNi(CN)4, a 2-D negative thermal expansion material, is one of a series of copper(II)-containing cyanides derived from Ni(CN)2. In CuNi(CN)4, unlike in Ni(CN)2, the cyanide groups are ordered generating square-planar Ni(CN)4 and Cu(NC)4 units. The adoption of square-planar geometry by Cu(II) in an extended solid is very unusual.

Is a lower dose of vitamin D supplementation enough to increase 25(OH)D status in a sunny country?

Calcium and vitamin D are essential nutrients for bone metabolism Vitamin D can either be obtained from dietary sources or cutaneous synthesis. The study was conducted in subtropic weather; therefore, some might believe that the levels of solar radiation would be sufficient in this area. To evaluate calcium and vitamin D supplementation in postmenopausal women with osteoporosis living in a sunny country. A 3-month controlled clinical trial with 64 postmenopausal women with osteoporosis, mean age 62 +/- A 8 years. They were randomly assigned to either the supplement group, who received 1,200 mg of calcium carbonate and 400 IU (10 mu g) of vitamin D(3,) or the control group. Dietary intake assessment was performed, bone mineral density and body composition were measured, and biochemical markers of bone metabolism were analyzed. Considering all participants at baseline, serum vitamin D was under 75 nmol/l in 91.4% of the participants. The concentration of serum 25(OH)D increased significantly (p = 0.023) after 3 months of supplementation from 46.67 +/- A 13.97 to 59.47 +/- A 17.50 nmol/l. However, the dose given was limited in effect, and 86.2% of the supplement group did not reach optimal levels of 25(OH)D. Parathyroid hormone was elevated in 22.4% of the study group. After the intervention period, mean parathyroid hormone tended to decrease in the supplement group (p = 0.063). The dose given (400 IU/day) was not enough to achieve 25(OH)D concentration, considered optimal for bone health.

Focus on Vitamin D, Inflammation and Type 2 Diabetes

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

Crystallization and preliminary X-ray diffraction analysis of a class II phospholipase D from Loxosceles intermedia venom

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

Search for squarks and gluinos in events with jets and missing transverse energy using 2.1 fb(-1) of p(p)over-bar collision data at root s=1.96 TeV - D phi Collaboration

A data sample corresponding to an integrated luminosity of 2.1 fb(-1) collected by the D phi detector at the Fermilab Tevatron Collider was analyzed to search for squarks and gluinos produced in p (p) over bar collisions at a center-of-mass energy of 1.96 TeV. No evidence for the production of such particles was observed in topologies involving jets and missing transverse energy, and 95% C.L. lower limits of 379 GeV and 308 GeV were set on the squark and gluino masses, respectively, within the framework of minimal supergravity with tan beta = 3, A(0) = 0, and mu < 0. The corresponding previous limits are improved by 54 GeV and 67 GeV. (c) 2008 Elsevier B.V. All rights reserved.

The formation of CN and CN+ by direct radiative association

Rate coefficients for direct radiative association of carbon and nitrogen atoms to form CN, and of carbon ions and nitrogen atoms to form CN+ ions, are calculated for temperatures in the range of 300 to 14,700 K. For the CN molecule, the rate coefficients can be represented by the standard expression, k(CN)(T) = 7.87 x 10(-19)(T/300)(0.056) exp (-96.0/T) cm(3) s(-1) for temperatures between 300 and 2700 K and k(CN)(T) = 1.37 x 10(-18)(T/300)-0.128 exp (-520.1/T) cm(-3) s(-1) at T > 2700 K. For the CN+ ion, the corresponding expression is k(CN+)(T) = 1.08 x 10(-18)(T/300)(0.071) exp (-57.5/T) cm(-3) s(-1) for the temperature range studied. Calculated rate coefficients k(CN) are about 2 orders of magnitude lower than the canonical value used in the modeling of the chemistry of various astrophysical environments.

Mechanism for interplay between electron and ionic fluxes in KhFek[Fe(CN)(6)](l)center dot mH(2)O compounds

This paper develops a framework for the interpretation of ionic insertion/deinsertion reactions in an aqueous environment taking place in transition-metal hexacyanoferrates of the general formula KhFek3+ [Fe2+ (CN)(6)](l)center dot mH(2)O, also called Prussian Blue. Three different processes were fully separated in the electrochemistry of these films. It was clearly identified that one of these electrochemical processes involves the insertion/deinsertion of H3O+ (hydrated protons) through the channels of the KhFek3+ [Fe2+ (CN)(6)](l) center dot mH(2)O structure to reach the film electroneutrality during the electron transfer between Everitt's Salt and Prussian Blue. The other electrochemical processes involve K+ or H+ (proton) exchange through the water crystalline structure existing in the channels of the KhFek3+ [Fe2+(CN)(6)](l)center dot mH(2)O structure.

Expression of p53, Ki-67, and CD31 in the vaginal margins of radical hysterectomy in patients with stage IB carcinoma of the cervix

Objectives. This study was undertaken to evaluate the expression of p53, Ki-67, and CD31 both in the tumor and in the vaginal margins of radical hysterectomy in patients with stage IB squamous cell carcinoma of the cervix, as an attempt to use these proteins as possible markers for residual tumor in cervical cancer.Methods. Thirty patients with stage IB squamous cell carcinoma of the cervix were submitted to radical hysterectomy (study group), and thirty patients with uterine myoma were submitted to vaginal hysterectomy (control group) and were prospectively studied from November 2001 to September 2002. Tissue samples were taken from the tumor or cervix, anterior vaginal margin (AVM), and posterior vaginal margin (PVM) and were immunohistochemically evaluated by monoclonal antibodies for p53, Ki-67, and CD31. Vaginal samples in which the histological examination showed tumor involvement were excluded from the study.Results. Patient's mean age was 48.7 +/- 10.4 years (27-73 years). The clinical stage was IB1 in 22 patients (73.3%) and IB2 in eight patients (26.7%). The expressions of p53, Ki-67, and CD31 were significantly higher in the tumor than in the benign cervix (P < 0.001). Higher expressions of these markers were noted in the vaginal margins of radical hysterectomy in patients with cervical carcinoma compared to the vaginal margins of control patients. This association was demonstrated for p53 in the AVM proximal (P = 0.045), for Ki-67 in AVM proximal (P < 0.001), AVM distal (P < 0.001), PVM proximal (P = 0.009), and PVM distal (P < 0.001), and for CD31 in AVM proximal (P = 0.003) and AVM distal (P = 0.018). There was no difference in p53, Ki-67, and CD31 expression between the proximal and distal regions of the vaginal margins in patients with carcinoma of the cervix.Conclusion. The expressions of p53, Ki-67, and CD31 were significantly higher in both the histologically positive (cervical tumor) and negative (vaginal margins) tissues of patients who had undergone radical hysterectomy for cervical cancer compared to the benign control tissues. (C) 2004 Elsevier B.V. All rights reserved.

Thermal and spectroscopy investigation of cyclopalladated compounds of the type [Pd(C(1)3H(1)0N)(mu-X)](2), (X=H3CCOO, NCO, SCN, CN)

The dimeric compound [Pd(bzan)(mu-OOCCH3)](2) (1) (bzan=N-benzylideneaniline) reacts with KX, in methanol/acetone (2:1), affording the analogous dimeric pseudohalogen-bridged species [Pd(bzan)(mu-X)](2) [X=NCO(2), SCN(3), CN(4)]. The compounds were characterized by elemental analysis, infrared spectroscopy, NMR and thermogravimetric analysis. IR data for 2-4 showed bands typical of coordinated pseudohalogen ligands clearly indicating the occurrence of the exchange reaction. Their thermal behaviour was investigated and suggested that their stability is influenced by the bridging ligand. The thermal stability decreased in the order [Pd(bzan)(mu-CN)](2)>[Pd(bzan)(mu-SCN)](2)>[Pd(bzan)(mu-OOCCH3)](2)>[Pd(bzan)(mu-NCO)](2). X-ray results showed the formation of Pddegrees as final decomposition product.

Kinetic aspects of ion exchange in KhFek[Fe(CN)(6)](l)center dot mH(2)O compounds: A combined electrical and mass transfer functions approach

The present paper quantifies and develops the kinetic aspects involved in the mechanism of interplay between electron and ions presented elsewhere(1) for KhFek[Fe(CN)(6)](l)center dot mH(2)O (Prussian Blue) host materials. Accordingly, there are three different electrochemical processes involved in the PB host materials: H3O+, K+, and H+ insertion/extraction mechanisms which here were fully kinetically studied by means of the use of combined electronic and mass transfer functions as a tool to separate all the processes. The use of combined electronic and mass transfer functions was very important to validate and confirm the proposed mechanism. This mechanism allows the electrochemical and chemical processes involved in the KhFek[Fe(CN)(6)](l)center dot mH(2)O host and Prussian Blue derivatives to be understood. In addition, a formalism was also developed to consider superficial oxygen reduction. From the analysis of the kinetic processes involved in the model, it was possible to demonstrate that the processes associated with K+ and H+ exchanges are reversible whereas the H3O+ insertion process was shown not to present a reversible pattern. This irreversible pattern is very peculiar and was shown to be related to the catalytic proton reduction reaction. Furthermore, from the model, it was possible to calculate the number density of available sites for each intercalation/deintercalation processes and infer that they are very similar for K+ and H+. Hence, the high prominence of the K+ exchange observed in the voltammetric responses has a kinetic origin and is not related to the amount of sites available for intercalation/deintercalation of the ions.

Thermodynamic aspects of ion intercalation in KhFek[Fe(CN)(6)](l)center dot mH(2)O compounds: Application to the Everit's salt/Prussian Blue transition

The K+ reversible processes for ion exchange in KhFek[Fe(CN)(6)](l)center dot mH(2)O host compounds (Prussian Blue) were thermodynamically analyzed. A thermodynamic approach was established and developed based on the consideration of a lattice-gas model where the electronic contribution to the chemical potential is neglected and the ion-host interaction is not considered. The occupation fraction of the intercalation process was calculated from the kinetic parameters obtained through ac-electrogravimetry in a previous paper. In this way, the mass potential transfer function introduces a new way to evaluate the thermodynamic aspect of intercalation. Finally, based on the thermodynamic approach, the energy used to put each K+ ion into the host material was calculated. The values were shown to be in good agreement with the values obtained through transient techniques, for example, cyclic voltammetry. As a result, this agreement between theory and experimental data validates the thermodynamic approach considered here, and for the first time, the thermodynamic aspects of insertion were considered for mixed valence materials.

Effets d'une immigration dans quelques populations modèles

Inclut la bibliographie

Programa de trabajo y orden de prelación: informe del Secretario Ejecutivo a la Comisión Económica para América Latina en su cuarto período de sesiones sobre la marcha de los trabajos = Work programme and priorities: Progress Report by the Executive Secretary to the Fourth Session of the Economic Commission for Latin America = Programme du travail et ordre des prioritats: Rapport soumis par le Secretaire Executif a la cuatrieme session de la Commission Economique pour l'Amerique Latine sur l'etat d'avancement des travaux

Incluye Bibliografía