Discovery of two distinct red clumps in NGC 419: a rare snapshot of a cluster at the onset of degeneracy

Colour-magnitude diagrams (CMDs) of the Small Magellanic Cloud (SMC) star cluster NGC 419, derived from Hubble Space Telescope (HST)/Advanced Camera for Surveys (ACS) data, reveal a well-delineated secondary clump located below the classical compact red clump typical of intermediate-age populations. We demonstrate that this feature belongs to the cluster itself, rather than to the underlying SMC field. Then, we use synthetic CMDs to show that it corresponds very well to the secondary clump predicted to appear as a result of He-ignition in stars just massive enough to avoid e(-)-degeneracy settling in their H-exhausted cores. The main red clump instead is made of the slightly less massive stars which passed through e(-) degeneracy and ignited He at the tip of the red giant branch. In other words, NGC 419 is the rare snapshot of a cluster while undergoing the fast transition from classical to degenerate H-exhausted cores. At this particular moment of a cluster`s life, the colour distance between the main-sequence turn-off and the red clump(s) depends sensitively on the amount of convective core overshooting, Lambda(c). By coupling measurements of this colour separation with fits to the red clump morphology, we are able to estimate simultaneously the cluster mean age (1.35(-0.04)(+0.11) Gyr) and overshooting efficiency (Lambda(c) = 0.47(-0.04)(+0.14)). Therefore, clusters like NGC 419 may constitute important marks in the age scale of intermediate-age populations. After eye inspection of other CMDs derived from HST/ACS data, we suggest that the same secondary clump may also be present in the Large Magellanic Cloud clusters NGC 1751, 1783, 1806, 1846, 1852 and 1917.

Reduced venous endothelial responsiveness after oral lipid overload in healthy volunteers

The aim of this study was to investigate endothelial venous function, mflammatory markers, and systemic oxidative stress after an oral lipid overload (OLO). We studied 18 healthy adults (9 men; age, 29.2 +/- 0.9 years; body mass index, 22.3 +/- 0.4 kg/m(2)). Blood samples were collected in the fasting state and 3, 4, and 5 hour after the OLO (1000 kcal, 58% fat) for metabolic variables, oxidative stress, inflammatory markers, adiponectin, and resistin. Changes in vein diameter to phenylephrine, acetylcholine, and sodium nitroprusside (dorsal hand vein technique) were measured before and after the OLO. Oral lipid overload increased triglycerides (61 +/- 6 vs 134 +/- 17 mg/dL, P <.001), insulin (7.2 +/- 0.8 vs 10.7 +/- 1.3 mu U/mL, P <.05), and resistin (5.38 +/- 0.5 vs 6.81 +/- 0.7 ng/mL, P <.05) and reduced antioxidant capacity (plasma total antioxidant capacity: 186.7 +/- 56 vs 161.8 +/- 50 U Trolox per microliter plasma, P <.01), vascular reactivity (171.3 +/- 85 vs 894.4 +/- 301 ng/mL, P <.001), and maximum acetylcholine venodilation (105.9% +/- 9% vs 61.0% +/- 7%, P <.05). No changes were observed for sodium nitroprusside. Post-OLO triglycerides were positively correlated with phenylephrine dose (rho = 0.38, P <.05) and resistin (rho = 0.43, P <.01) and negatively correlated with the maximum acetylcholine venodilation (rho = -0.36, P <.05). In conclusion, an OLO impaired venoconstriction responsiveness in healthy subjects, probably because of a reduction in the antioxidant capacity. (C) 2008 Elsevier Inc. All rights reserved.

Embryonic Development of Ampheres leucopheus and lporangaia pustulosa (Arachnida: Opiliones: Gonyleptidae)

The first studies concerning the embryonic development of harvestmen started in the late 19th century, and focused mostly on holarctic species, and only three species of the suborder Laniatores (the largest, among the four suborders considered presently) were studied. Moreover, the last studies on embryology of harvestmen were made during the late 1970s. This study focused on the embryonic development of Ampheres leucopheus (Gonyleptidae, Caelopyginae) and Iporangaia pustulosa (Gonyleptidae, Progonyleptoidellinae). The embryonic development was followed in the field, by taking daily photographs of different eggs during about 2 months. When laid, eggs of A. leucopheus and I pustulosa have approximately 1.13 and 1.30 mm in diameter, respectively, and the second is embedded in a large amount of mucus. The eggs grow, mainly due to water absorption at the beginning of the process, and they reach a diameter of about 1.35 and 1.59 mm, respectively, close to hatching. It took, respectively, 29-56 days and 35-66 days from egg laying to hatching. For the description of the embryonic development, we use photographs from the field, SEM micrographs, and histological analysis. This allowed us, for instance, to document the progression of structures and pigmentation directly from live embryos in the field, and to record microstructures, such as the presence of perforations in the cuticle of the embryo in the place where eyes are developing. Yet, contrary to what was expected in the literature, we record an egg tooth in one of the studied laniatoreans. J. Exp. Zool. (Mol. Dev. Evol) 314B:489-502, 2010. (C) 2010 Wiley-Liss, Inc.

(65)Zn(2+) transport by isolated gill epithelial cells of the American lobster, Homarus americanus

Gills are the first site of impact by metal ions in contaminated waters. Work on whole gill cells and metal uptake has not been reported before in crustaceans. In this study, gill filaments of the American lobster, Homarus americanus, were dissociated in physiological saline and separated into several cell types on a 30, 40, 50, and 80% sucrose gradient. Cells from each sucrose solution were separately resuspended in physiological saline and incubated in (65)Zn(2+) in order to assess the nature of metal uptake by each cell type. Characteristics of zinc accumulation by each kind of cell were investigated in the presence and absence of 10 mM calcium, variable NaCl concentrations and pH values, and 100 mu M verapamil, nifedipine, and the calcium ionophore A23187. (65)Zn(2+) influxes were hyperbolic functions of zinc concentration (1-1,000 mu M) and followed Michaelis-Menten kinetics. Calcium reduced both apparent zinc binding affinity (K (m)) and maximal transport velocity (J (max)) for 30% sucrose cells, but doubled the apparent maximal transport velocity for 80% sucrose cells. Results suggest that calcium, sodium, and protons enter gill epithelial cells by an endogenous broad-specificity cation channel and trans-stimulate metal uptake by a plasma membrane carrier system. Differences in zinc transport observed between gill epithelial cell types appear related to apparent affinity differences of the transporters in each kind of cell. Low affinity cells from 30% sucrose were inhibited by calcium, while high affinity cells from 80% sucrose were stimulated. (65)Zn(2+) transport was also studied by isolated, intact, gill filament tips. These intact gill fragments generally displayed the same transport properties as did cells from 80% sucrose and provided support for metal uptake processes being an apical phenomenon. A working model for zinc transport by lobster gill cells is presented.

Ciprofibrate quantification in human plasma by high-performance liquid chromatography coupled with electrospray tandem mass spectrometry for pharmacokinetic studies

A rapid, sensitive and specific method for quantifying ciprofibrate in human plasma using bezafibrate as the internal standard (IS) is described. The sample was acidified prior extraction with formic acid (88%). The analyte and the IS were extracted from plasma by liquid-liquid extraction using an organic solvent (diethyl ether/dichloromethane 70/30 (v/v)). The extracts were analyzed by high performance liquid chromatography coupled with electrospray tandem mass spectrometry (HPLC-MS/MS). Chromatography was performed using Genesis C18 4 mu m analytical column (4.6 x 150 mm i.d.) and a mobile phase consisting of acetonitrile/water (70/30, v/v) and 1 mM acetic acid. The method had a chromatographic run time of 3.4 min and a linear calibration curve over the range 0.1-60 mu g/mL (r > 0.99). The limit of quantification was 0.1 mu g/mL. The intra- and interday accuracy and precision values of the assay were less than 13.5%. The stability tests indicated no significant degradation. The recovery of ciprofibrate was 81.2%, 73.3% and 76.2% for the 0.3, 5.0 and 48.0 ng/mL standard concentrations, respectively. For ciprofibrate, the optimized parameters of the declustering potential, collision energy and collision exit potential were -51 V, -16 eV and -5 V, respectively. The method was also validated without the use of the internal standard. This HPLC-MS/MS procedure was used to assess the bioequivalence of two ciprofibrate 100 mg tablet formulations in healthy volunteers of both sexes. The following pharmacokinetic parameters were obtained from the ciprofibrate plasma concentration vs. time curves: AUC(last), AUC(0-168 h), C(max) and T(max). The geometric mean with corresponding 90% confidence interval (CI) for test/reference percent ratios were 93.80% (90% CI = 88.16-99.79%) for C(max), 98.31% (90% CI = 94.91-101.83%) for AUC(last) and 97.67% (90% CI = 94.45-101.01%) for AUC(0-168 h). Since the 90% Cl for AUC(last), AUC(0-168 h) and C(max) ratios were within the 80-125% interval proposed by the US FDA, it was concluded that ciprofibrate (Lipless (R) 100 mg tablet) formulation manufactured by Biolab Sanus Farmaceutica Ltda. is bioequivalent to the Oroxadin (R) (100 mg tablet) formulation for both the rate and the extent of absorption. (C) 2011 Published by Elsevier B.V.

The role of endothelin pathway in modulation of airway reactivity to methacholine in C57Bl/6 and BALB/c mice

Endothelin peptides have been shown to increase cholinergic neurotransmission in the airway. Genetic differences in airway responsiveness to methacholine where reported in mice. The present study compared the airway reactivity to methacholine in C57Bl/6 and BALB/c mice, the involvement of endothelin on this reactivity and endothelin levels in lung homogenates. Whole airway reactivity was analyzed by means of an isolated lung preparation where lungs were perfused through the trachea with warm gassed Krebs solution at 5 ml/min, and changes in perfusion pressure triggered by methacholine at increasing bolus doses (0.1-100 mu g) were recorded. We found that the maximal airway response to methacholine was much greater in C57Bl/6 than in BALB/c (Emax 34 +/- 2 vs 12 +/- 1 cmH(2)O, respectively). Bosentan (mixed endothelin A/B receptor antagonist; 10 mg/kg, i.p., 30 min before sacrifice) reduced lung responsiveness to methacholine in C57Bl/6 (58% at EC50 level) but had no effect in BALB/c mouse strain. This effect seems to be mediated by the endothelin ETA receptor since it was significantly reduced by the selective endothelin ETA receptor antagonist, BQ 123. Immunoreactive endothelin levels were higher in C57Bl/6 than in BALB/c lungs (43 5 vs 19 +/- 5 pg/g of tissue). In conclusion, airway reactivity to methacholine and lung endothelins content varies markedly between C57Bl/6 and BALB/c strains. Endothelins upregulate lung responsiveness to methacholine only in C57Bl/6, an effect achieved through the endothelin ETA receptor. (C) 2008 Elsevier B.V. All rights reserved.

Disruption of the 2-methylcitric acid cycle and evaluation of poly-3-hydroxybutyrate-co-3-hydroxyvalerate biosynthesis suggest alternate catabolic pathways of propionate in Burkholderia sacchari

The objective of the present work was to evaluate the relevance of the 2-methylcitric acid cycle (2MCC) to the catabolism of propionate in Burkholderia sacchari. Two B. sacchari mutants unable to grow on propionate were obtained: one disrupted in acnM, and the other in acnM and prpC deleted. An operative 2MCC significantly reduces the bacterial ability to incorporate 3-hydroxyvalerate (3HV) into a biodegradable copolyester accumulated from carbohydrates plus propionate. The efficiency of the mutants in converting propionate to 3HV units (Y(3HV/prp)) increased from 0.09 g.g(-1) to 0.81-0.96 g.g(-1), indicating that acnM and prpC are both essential for growth on propionate. None of the mutations resulted in achievement of the maximum theoretical Y(3HV/prp) (1.35 g.g(-1)). When increasing concentrations of propionate were supplied, decreasing values of Y(3HV/prp) were observed. The results obtained corroborate the hypothesis of the presence of other propionate catabolic pathways in B. sacchari. The 2MCC would be the more operative pathway, but a second pathway, which remains to be elucidated, would assume more importance under propionate concentrations of 1 g.L(-1) or higher. The efficiency in converting propionate to 3HV units can be improved by decreasing the propionate concentrations, owing to the role of the 2MCC.

In Vitro and In Vivo Antiplasmodial Activities of Risedronate and Its Interference with Protein Prenylation in Plasmodium falciparum

The increasing resistance of malarial parasites to almost all available drugs calls for the identification of new compounds and the detection of novel targets. Here, we establish the antimalarial activities of risedronate, one of the most potent bisphosphonates clinically used to treat bone resorption diseases, against blood stages of Plasmodium falciparum (50% inhibitory concentration [IC(50)] of 20.3 +/- 1.0 mu M). We also suggest a mechanism of action for risedronate against the intraerythrocytic stage of P. falciparum and show that protein prenylation seems to be modulated directly by this drug. Risedronate inhibits the transfer of the farnesyl pyrophosphate group to parasite proteins, an effect not observed for the transfer of geranylgeranyl pyrophosphate. Our in vivo experiments further demonstrate that risedronate leads to an 88.9% inhibition of the rodent parasite Plasmodium berghei in mice on the seventh day of treatment; however, risedronate treatment did not result in a general increase of survival rates.

Effects of aerobic exercise on the blood pressure, oxidative stress and eNOS gene polymorphism in pre-hypertensive older people

The polymorphisms of endothelial nitric oxide synthase (eNOS) are associated with reduced eNOS activity. Aerobic exercise training (AEX) may influence resting nitric oxide (NO) production, oxidative stress and blood pressure. The purpose of this study was to investigate the effect of AEX on the relationship among blood pressure, eNOS gene polymorphism and oxidative stress in pre-hypertensive older people. 118 pre-hypertensive subjects (59 +/- A 6 years) had blood samples collected after a 12 h overnight fast for assessing plasma NO metabolites (NOx) assays, thiobarbituric acid reactive substances (T-BARS) and superoxide dismutase activity (ecSOD). eNOS polymorphism (T-786C and G-894T) was done by standard PCR methods. All people were divided according to the genotype results (G1: TT/GG, G2: TT/GT + TT, G3: TC + CC/GG, G4: TC + CC/GT + TT). All parameters were measured before and after 6 months of AEX (70% of VO(2 max)). At baseline, no difference was found in systolic and diastolic blood pressure, ecSOD and T-BARS activity. Plasma NOx levels were significantly different between G1 (19 +/- A 1 mu M) and G4 (14.2 +/- A 0.6 mu M) and between G2 (20.1 +/- A 1.7 mu M) and G4 (14.2 +/- A 0.6 mu M). Therefore, reduced NOx concentration in G4 group occurred only when the polymorphisms were associated, suggesting that these results are more related to genetic factors than NO-scavenging effect. After AEX, the G4 increased NOx values (17.2 +/- A 1.2 mu M) and decreased blood pressure. G1, G3 and G4 decreased T-BARS levels. These results suggest the AEX can modulate the NOx concentration, eNOS activity and the relationship among eNOS gene polymorphism, oxidative stress and blood pressure especially in C (T-786C) and T (G-894T) allele carriers.

MAGNETIC RESONANT X-RAY DIFFRACTION APPLIED TO THE STUDY OF EuTe FILMS AND MULTILAYERS

In this work we use magnetic resonant x-ray diffraction to study the magnetic properties of a 1.5 mu m EuTe film and an EuTe/PbTe superlattice (SL). The samples were grown by molecular beam epitaxy on (111) oriented BaF(2) substrates. The measurements were made at the Eu L(2) absorption edge, taking profit of the resonant enhancement of more than two orders in the magnetically diffracted intensity. At resonance, high counting rates above 11000 cps were obtained for the 1.5 gm EuTe film, allowing to check for the type II antiferromagnetic order of EuTe. An equal population of the three possible in-plane magnetic domains was found. The EuTe/PbTe SL magnetic peak showed a satellite structure, indicating the presence of magnetic correlations among the 5 ML (monolayers) EuTe layers across the 15 ML PbTe non-magnetic spacers. The temperature dependence of the integrated intensities of the film and the SL yielded different Neel temperatures T(N). The lower T(N) for the SL is explained considering the higher influence of the surface atoms, with partial bonds lost.

Infrared emissions, visible up-conversion, thermoluminescence and defect centres in Er(3)Al(5)O(12) phosphor obtained by solution combustion reaction

The Er(3)Al(5)O(12) phosphor powders were prepared using the solution combustion method. Formation and homogeneity of the Er(3)Al(5)O(12) phosphor powders have been verified by X-ray diffraction and energy-dispersive X-ray analysis respectively. The frequency up-conversion from Er(3)Al(5)O(12) phosphor powder corresponding to the (2)H(9/2) -> (4)I(15/2), (2)H(11/2) -> (4)I(15/2), (4)S(3/2) -> (4)I(15/2), (4)F(9/2) -> (4)I(15/2) and the infrared emission (IR) due to the (4)I(13/2) -> (4)I(15/2) transitions lying at similar to 410, similar to 524, similar to 556, 645-680 nm and at similar to 1.53 mu m respectively upon excitation with a Ti-Sapphire pulsed/CW laser have been reported. The mechanism responsible for the frequency up-conversion and IR emission is discussed in detail. Defect centres induced by radiation were studied using the techniques of thermoluminescence and electron spin resonance. A single glow peak at 430A degrees C is observed and the thermoluminescence results show the presence of a defect center which decays at high temperature. Electron spin resonance studies indicate a center characterized by a g-factor equal to 2.0056 and it is observed that this center is not related to the thermoluminescence peak. A negligibly small concentration of cation and anion vacancies appears to be present in the phosphor in accordance with the earlier theoretical predictions.

Infrared emission and defect centres in Er and Yb codoped Y(3)Al(5)O(12) phosphors

YAG phosphor powders doped/codoped with Er(3+)/(Er(3+) + Yb(3+)) have been synthesised by using the solution combustion method. The effect of direct pumping into the (4)I(11/2) level under 980 nm excitation of doped/codoped Er(3+)/Yb(3+)-Er(3+) in Y(3)Al(5)O(12) (YAG) phosphor responsible for an infrared (IR) emission peaking at similar to 1.53 mu m corresponding to the (4)I(13/2)->(4)I(15/2) transition has been studied. YAG exhibits three thermally-stimulated luminescence (TSL) peaks at around 140A degrees C, 210A degrees C and 445A degrees C. Electron spin resonance (ESR) studies were carried out to identify the centres responsible for the TSL peaks. The room temperature ESR spectrum of irradiated phosphor appears to be a superposition of two distinct centres. One of the centres (centre I) with principal g-value 2.0176 is identified as O(-) ion, while centre II with an isotropic g-factor 2.0020 is assigned to an F(+) centre (singly ionised oxygen vacancy). An additional defect centre is observed during thermal-annealing experiments and this centre (assigned to F(+) centre) seems to originate from an F-centre (oxygen vacancy with two electrons) and these two centres appear to correlate with the observed high-temperature TSL peak in YAG phosphor.

Infrared luminescence, thermoluminescence and defect centres in Er and Yb co-doped ZnAl(2)O(4) phosphor

Er and Yb co-doped ZnAl(2)O(4) phosphors were prepared by solution combustion synthesis and the identification of Er and Yb were done by energy-dispersive X-ray analysis (EDX) studies. A luminescence at 1.5 mu m, due to the (4)I(13/2) ->(4)I(15/2) transition, has been studied in the NIR region in Er and Yb co-doped ZnAl(2)O(4) phosphors upon 980 nm CW pumping. Er-doped ZnAl(2)O(4) exhibits two thermally stimulated luminescence (TSL) peaks around 174A degrees C and 483A degrees C, while Yb co-doped ZnAl(2)O(4) exhibits TSL peaks around 170A degrees C and 423A degrees C. Electron spin resonance (ESR) studies were carried out to identify defect centres responsible for TSL peaks observed in the phosphors. Room temperature ESR spectrum appears to be a superposition of two distinct centres. These centres are assigned to an O(-) ion and F(+) centre. O(-) ion appears to correlate with the 174A degrees C TSL peak and F(+) centre appears to relate with the high temperature TSL peak at 483A degrees C in ZnAl(2)O(4):Er phosphor.

Er:YAl(3)(BO(3))(4) glassy thin films from polymeric precursor and sol-gel methods: Waveguides for integrated optics

This paper presents the characterization of single-mode waveguides for 980 and 1550 nm wavelengths. High quality planar waveguide structure was fabricated from Y(1-x)Er(x)Al(3)(BO(3))(4) multilayer thin films with x = 0.02, 0.05, 0.1, 0.3, and 0.5, prepared through the polymeric precursor and sol-gel methods using spin-coating. The propagation losses of the planar waveguides varying from 0.63 to 0.88 dB/cm were measured at 632.8 and 1550 nm. The photoluminescence spectra and radiative lifetimes of the Er(3+) (4)I(13/2) energy level were measured in waveguiding geometry. For most samples the photoluminescence decay was single exponential with lifetimes in between 640 mu s and 200 mu s, depending on the erbium concentration and synthesis method. These results indicate that Er doped YAl(3)(BO(3))(4) compounds are promising for low loss waveguides. (C) 2009 Elsevier B.V. All fights reserved.

Vanadium complexes with thiosemicarbazones: Synthesis, characterization, crystal structures and anti-Mycobacterium tuberculosis activity

The development of more efficient anti-tuberculosis drugs is of interest. Three oxovanadium(IV) and three cis-dioxovanadium(V) complexes with thiosemicarbazone derivatives bearing moieties with different lipophilicity have been prepared and had their inhibitory activity against Mycobacterium tuberculosis H(37)Rv ATCC 27294 evaluated. The analytical methods used by the complexes` characterization included IR, EPR, (1)H, (13)C and (51)V NMR spectroscopies, elemental analysis, cyclic voltammetry, magnetic susceptibility measurement and single crystal X-ray diffractometry. [VO(acac)(aptsc)], [VO(acac)(apmtsc)] and [VO(acac)(apptsc)] (acac = acetylacetonate; Haptsc = 2-acetylpyridinethiosemicarbazone; Hapmtsc = 2-acetylpyridine-N(4)-methyl-thiosemicarbazone and Happtsc = 2-acetylpyridine-N(4)-phenyl-thiosemicarbazone) are paramagnetic and their EPR spectra are consistent with the monoanionic N,N,S-tridentate coordination of the thiosemicarbazone ligands, resulting in octahedral structures of rhombic symmetry and with the oxidation state +IV for the vanadium atom. As result of oxidation of the vanadium(IV) complexes above, the diamagnetic cis-dioxovanadium(V) complexes [VO(2)(aptsc)[, [VO(2)(apmtsc)[ and [VO(2)(apptsc)] are formed. Their (1)H, (13)C and (51)V NMR spectra were acquired and support a distorted square pyramidal geometry for them, in accord with the solid state X-ray structures determined for [VO(2)(aptsc)] and [VO(2)(apmtsc)]. In general, the vanadium compounds show comparable or larger anti-M. tuberculosis activities than the free thiosemicarbazone ligands, with MIC values within 62.5-1.56 (mu g/mL). (C) 2008 Elsevier Ltd. All rights reserved.