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Uno de los retos actuales en la enfermedad de Parkinson (EP) y otros trastornos del movimiento (TM) consiste en cómo y cuándo aplicar la atención paliativa. Conocedores de la escasa formación e implementación de este tipo de abordajes planteamos unas recomendaciones consensuadas de los cuidados paliativos (CP) con el fin de mejorar la calidad de vida de los pacientes y su entorno.

La atención paliativa en enfermedades neurodegenerativas es útil pero infrautilizada. El objetivo de este estudio es conocer cómo se aplican en nuestro país los cuidados paliativos (CP) en los pacientes con trastornos del movimiento (TM) de cara a identificar posibles limitaciones y necesidades no cubiertas.

Aims. We seek to detect and quantify the effects of surface convection (granulation) on the line spectra of K-dwarfs as a first step towards a rigorous testing of hydrodynamic models for their atmospheres.

The abundances of iron and oxygen are homogeneously determined in a sample of 523 nearby ($d<$150 pc) FGK disk and halo stars with metallicities in the range -1.5<[Fe/H]<0.5. Iron abundances were obtained from an LTE analysis of a large set of $\ion{Fe}{i}$and $\ion{Fe}{ii}$lines with reliable atomic data. Oxygen abundances were inferred from a restricted non-LTE analysis of the 777 nm $\ion{O}{i}$triplet. We adopted the infrared flux method temperature scale and surface gravities based on Hipparcostrigonometric parallaxes. Within this framework, the ionization balance of iron lines is not satisfied: the mean abundances from the $\ion{Fe}{i}$lines are systematically lower by 0.06 dex than those from the $\ion{Fe}{ii}$lines for dwarf stars of $T_{\mathrm{eff}}>$5500 K and [Fe/H]<0.0, and giant stars of all temperatures and metallicities covered by our sample. The discrepancy worsens for cooler and metal-rich main-sequence stars. We use the stellar kinematics to compute the probabilities of our sample stars to be members of the thin disk, thick disk, or halo of the Galaxy. We find that the majority of the kinematically-selected thick-disk stars show larger [O/Fe] ratios compared to thin-disk stars while the rest show thin-disk abundances, which suggests that the latter are thin-disk members with unusual (hotter) kinematics. A close examination of this pattern for disk stars with ambiguous probabilities shows that an intermediate population with properties between those of the thin and thick disks does not exist, at least in the solar neighborhood. Excluding the stars with unusual kinematics, we find that thick-disk stars show slowly decreasing [O/Fe] ratios from about 0.5 to 0.4 in the -0.8<[Fe/H]<-0.3 range. Using a simple model for the chemical evolution of the thick disk we show that this trend results directly from the metallicity dependence of the Type II supernova yields. At [Fe/H]>-0.3, we find no obvious indication of a sudden decrease (i.e., a “knee”) in the [O/Fe] vs. [Fe/H] pattern of thick-disk stars that would connect the thick and thin disk trends at a high metallicity. We conclude that Type Ia supernovae (SN Ia) did not contribute significantly to the chemical enrichment of the thick disk. In the -0.8<[Fe/H]<+0.3 range, thin-disk stars show decreasing [O/Fe] ratios from about 0.4 to 0.0 that require a SN Ia contribution. The implications of these results for studies of the formation and evolution of the Galactic disk are discussed.

The atmospheric parameters and iron abundance of the Sloan Digital Sky Survey(SDSS) spectrophotometric standard star BD +17 4708 are critically examined using up-to-date Kurucz model atmospheres, LTE line formation calculations, and reliable atomic data. We find $T_{{\rm eff}}=6141$±50 K, $\log g=3.87$±0.08, and ${\rm [Fe/H]}=-1.74$±0.09. The line-of-sight interstellar reddening, bolometric flux, limb-darkened angular diameter, stellar mass, and the abundances of Mg, Si, and Ca are also obtained: $E(B-V)=0.010$±0.003, $f_{{\rm bol}}=(4.89\pm0.10)$$\times$10-9erg cm-2s-1, $\theta=0.1016$±0.0023 mas, $M=0.91$±$0.06~M_\odot$, ${\rm [Mg/Fe]}=0.40$±0.10, ${\rm [Si/Fe]}=0.35$±0.11, ${\rm [Ca/Fe]}=0.36$±0.11. This star is a unique example of a moderately metal-poor star for which the effective temperature ($T_{{\rm eff}}$) can be accurately constrained from the observedspectral energy distribution (corrected for reddening). Such analysis leads to a value that is higher than most spectroscopic results previously reported in the literature (~5950 K). Interstellar reddening was estimated using various prescriptions, including an analysis of interstellar lines. The surface gravity of the star was inferred from the fitting of the wings of the $\ion{Mg}{i}$blines. We used transition probabilities measured in the laboratory and reliable damping constants for unblended Fe lines to derive the iron abundance using both $\ion{Fe}{i}$and $\ion{Fe}{ii}$lines. We find that the ionization balance of Fe lines is satisfied only if a low $T_{{\rm eff}}$(~5950 K) is adopted. The mean iron abundance we obtain from the $\ion{Fe}{ii}$lines corresponds to $A_{\rm Fe}=5.77$±0.09 (${\rm [Fe/H]}=-1.74$for our derived $A_{{\rm Fe},\odot}=7.51$) while that from the $\ion{Fe}{i}$lines is $A_{\rm Fe}=5.92$±0.11, and therefore with our preferred $T_{{\rm eff}}$(6141 K), the discrepancy between the mean iron abundance from $\ion{Fe}{i}$and $\ion{Fe}{ii}$lines cannot be explained by overionization by UV photons as the main non-LTE effect. Interestingly, the $\ion{Fe}{i}$excitation balance is satisfied with a $T_{{\rm eff}}$only slightly warmer than our preferred solution and not with the lower value of 5950 K. We also comment on non-LTE effects and the importance of inelastic collisions with neutral H atoms in the determination of oxygen abundances in metal-poor stars from the 7774 Å $\ion{O}{i}$triplet.

Based on a large sample of disk and halo giant stars for which accurate effective temperatures derived through the InfraRed Flux Method (IRFM) exist, a calibration of the temperature scale in the Vilnius, Geneva, $RI_\mathrm{(C)}$and DDO photometric systems is performed. We provide calibration formulae for the metallicity-dependent $T_\mathrm{eff}$vs. color relations as well as grids of intrinsic colors and compare them with other calibrations. Photometry, atmospheric parameters and reddening corrections for the stars of the sample have been updated with respect to the original sources to reduce the dispersion of the fits. Application of our results to Arcturus leads to an effective temperature in excellent agreement with the value derived from its angular diameter and integrated flux. The effects of gravity on these $T_\mathrm{eff}$vs. color relations are also explored by taking into account our previous results for dwarf stars.

The present review summarizes the methods most used in drug search and design, which may help to keep pace with the growing antibiotic resistance among pathogens. The rate of reduction in the effectiveness of many antimicrobial medications, caused by this resistance, is faster than new drug development, thereby creating a worldwide public health threat. Among the scientific community, the urgency of finding new drugs is peaking interest in the use of in silico studies to explore the interaction of compounds with target receptors. With this approach, small molecules (designed or retrieved from data bases) are tested with computer-aided molecular simulation to explore their efficacy. That is, ligand-protein complexes are constructed and evaluated via virtual screening (VS), molecular dynamics (MD), and docking simulations with the data from the physical, chemical and pharmacological properties of such molecules. Additionally, the application of quantitative structure-activity relationship (QSAR), multi-target quantitative structure-activity relationship (mt- QSAR), and multi-tasking quantitative structure-biological effect (mtk-QSBER) can be enhanced by principal component analysis and systematic workflows. These types of studies aid in selecting a group of promising molecules with high potency and selectivity as well as low toxicity, thus making in vitro and in vivo (animal model) testing more efficient. Since knowledge of the receptor topography and receptor-ligand interactions has yielded promising compounds and effective drugs, there is now no doubt that the use of in silico tools can lead to more rapid validation of new potential drugs for preclinical studies and clinical trials.

We have used the infrared flux method (IRFM) temperatures of a large sample of late type dwarfs given by Alonso et al. ([CITE]) to calibrate empirically the relations $T_{\rm eff}=f$(colour, [Fe/H]) for the Vilnius, Geneva, $RI_{(\rm{\tiny C})}$(Cousins) and DDO photometric systems. The resulting temperature scale and intrinsic colour-colour diagrams for these systems are also obtained. From this scale, the solar colours are derived and compared with those of the solar twin 18 Sco. Since our work is based on the same Teffand [Fe/H] values used by Alonso et al. ([CITE]) to calibrate other colours, we now have an homogeneous calibration for a large set of photometric systems.

La Estrategia del Ictus del Sistema Nacional de Salud (EISNS) fue un documento de consenso entre las distintas administraciones y sociedades científicas que se desarrolló con el objetivo de mejorar la calidad del proceso asistencial y garantizar la equidad territorial. Nuestro objetivo fue analizar los recursos asistenciales existentes y si se había cumplido el objetivo de la EISNS.

Immunologic and genetic factors are involved in HIV-1/AIDS pathogenesis. Defensins are key molecules in innate immunity that participate in the control and/or development of infection and disease. Using PCR-RFLPs, we determined the association between HIV-1/AIDS and human β-defensin 1 (DEFB1) 5’UTR -52 G/A (rs1799946), -44 C/G (rs1800972), and -20 G/A (rs11362) polymorphisms in three groups of women from the state of Sinaloa, located in the Northwest region of Mexico: i) healthy blood donors; ii) sex-workers; and iii) HIV-1 patients. The -52GG genotype was more frequent in blood donors than in patients (p= 0.023; Odds Ratio, OR= 0.49; 95% CI= 0.25–0.95), whereas the - 52GA genotype was significantly higher in patients (p= 0.013; OR= 2.03; 95% CI= 1.11−3.79, statistical power SP= 98.8%), as well as the frequencies of -20A allele (p= 0.017; OR= 1.60; 95% CI= 1.06−2.40), -20AA genotype (p= 0.047; OR = 2.02; 95% CI= 0.93−4.33) and the ACA haplotype with respect to healthy blood donors (p= 0.000012; OR= 5.82; 95% CI= 2.33–16.43, SP= 99.89%) and sex-workers (p= 0.019; OR= 2.18; 95% CI= 1.07–4.46). Conversely, the ACG haplotype was higher in healthy blood donors than in patients (p= 0.009; OR= 0.55; 95% CI= 0.34–0.89). In addition, the -44CC genotype was associated with a low plasma viral load (p= 0.015), whereas AGA, AGG and GGA haplotypes were more prevalent in individuals with high CD4 counts (p= 0.004, 0.046, and 0.029, respectively). These findings associate DEFB1 5’UTR polymorphisms with HIV-1/AIDS in Mexican women for the first time.

Abstract: We study correlation properties of excursion increments of heartbeat time series from healthy subjects and heart failure patients. We construct the excursion time based on the original heartbeat time series, representing the time employed by the walker to return to the local mean value. Next, the detrended fluctuation analysis and the fractal dimension method are applied to the magnitude and sign of the increments in the time excursions between successive excursions for the mentioned groups. Our results show that for magnitude series of excursion increments both groups display long-range correlations with similar correlation exponents, indicating that large (small) increments (decrements) are more likely to be followed by large (small) increments (decrements). For sign sequences and for both groups, we find that increments are short-range anti-correlated, which is noticeable under heart failure conditions. [Copyright &y& Elsevier]

Positive immunostaining for the tumor suppressor protein p16 is associated with the presence of mucosal or alfa subtypes of human papillomavirus (HPV) in cervical and genital squamous cell carcinoma (SCC). The aim of this study was to determine whether p16 immunostaining is also associated with mucosal HPV in extragenital SCC.

Solar elastosis, or basophilic degeneration of collagen, may be a histologic sign of chronic sun damage.

Identification of organic compounds from plants is of clinical significance because of the effect that they might have in patients with haematopoietic disorders. We studied the effect of the plant extract Justicia spicigera (Acanthaceae) in different haematopoietic cells: human leukaemic cell lines, umbilical cord blood cells, and mouse bone marrow cells. By examining colony formation and performing the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay it was shown that the plant extract of Justicia spicigera contains cytotoxic factors for leukaemic cells and has no proliferative activity on normal haematopoietic progenitor cells. Our results show that this plant extract induces apoptosis in the human leukaemia cell line TF-1, but not in the bcl-2 transfectant cell line TB-1. Similar results were obtained using a haemopoietic cell line 32D and 32DBcl2. The cultures of umbilical cord blood cells and mouse bone marrow that contain granulocyte-macrophage colony-stimulating factor (GM-CSF) do not proliferate or become terminally differentiated in the presence of the infusion of Justicia spicigera. GM-CSF that acts by abrogating programmed cell death is not sufficient to inhibit the apoptotic stimulus in TF-1 and 32D cells. Moreover mouse fibroblasts (3T3) and two cervical carcinoma cell lines CALO and INBL, undergo apoptosis in the presence of different concentrations of an infusion from the plant. Our data show that there is a strong correlation between the cytotoxic effect and cell proliferation. Together, these results indicate that the plant infusion of Justicia spicigera does not contain any haematopoietic activity, induces apoptosis inhibited by bcl-2 and is linked to cell proliferation. Copyright © 2001 John Wiley & Sons, Ltd.

Identification of organic compounds from plants is of clinical significance because of the effect that they might have in patients with haematopoietic disorders. We studied the effect of the plant extract Justicia spicigera(Acanthaceae) in different haematopoietic cells: human leukaemic cell lines, umbilical cord blood cells, and mouse bone marrow cells.

A neutral triacylglycerol lipase activity that is separate and distinct from lipoprotein lipase (LPL) could be measured in homogenates of myocardial cells if protamine sulphate and high concentrations of albumin were included in the assay. This neutral lipase was predominantly particulate, with the highest relative specific activity in microsomal subcellular fractions. The induction of diabetes by the administration of streptozotocin to rats resulted in a decrease in LPL activity in myocyte homogenates and in particulate subcellular fractions, but the percentage of cellular LPL activity that was released during incubation of myocytes with heparin was normal. In contrast, neutral lipase activity was increased in diabetic myocyte homogenates and microsomal fractions. Acid triacylglycerol lipase activity was not changed in diabetic myocytes. The decrease in LPL in myocytes owing to diabetes may result in the decreased functional LPL activity at the capillary endothelium of the diabetic heart.

Triacylglycerol (TG) hydrolase activities were characterized in myocytes isolated from rat hearts. Acid hydrolase activity with a pH optimum of 5 could be measured in myocyte homogenates, and the subcellular distribution suggested that this activity originated in lysosomes. Lipoprotein lipase (LPL) was also present in myocyte homogenates, as evidenced by TG hydrolase activity that was stimulated by serum and apolipoprotein CII, and inhibited by apolipoprotein CIII2, high ionic strength (NaCl and MgCl2, I = 1 M) and antibodies to LPL. Serum-independent neutral (pH 7.5) TG hydrolase activity was less sensitive to inhibition by 1 M-NaCl, by antibodies to LPL and by preincubation at 40 degrees C than was serum-stimulated hydrolase activity. Furthermore, there were modest but significant differences in the subcellular distribution of the serum-independent and serum-stimulated hydrolase activities. Hydrolase activities in myocyte homogenates could be solubilized by 7.2 mM-deoxycholate. Acid hydrolase activity was recovered in the unbound fraction after heparin-Sepharose chromatography, whereas LPL was bound to the affinity column and was eluted by 0.9-1.2 M-NaCl. Approximately one-third of the serum-independent TG hydrolase activity was not bound to the heparin-Sepharose affinity column. This unbound TG hydrolase activity had a pH optimum of 7 and was stimulated by 50 mM-MgCl2, but not by serum and was resistant to inhibition by high ionic strength (1 M-NaCl), to preincubation at 40 degrees C for 2 h, and by antibodies to LPL. It is concluded that, in addition to an acid lysosomal TG hydrolase and LPL, myocytes from rat heart contain a serum-independent TG hydrolase with unique characteristics.

A study to evaluate the effect of ozone on solids removal during the coagulation-flocculation of wastewater from Mexico City drainage (including domestic and industrial) was conducted. Results of this study show significant improvements in the effluent quality with small ozone doses. The optimum ozone dosage was found to be 3.32 mg L-1 ± 0.20. With this dosage it is possible to reduce the coagulant concentration from 50 mg L-1 to 40 mg L-1 without affecting the effluent quality. When coagulant dose is not reduced, an increase in the flocs' settling velocity due to a larger average size (with a decrease in TSS) is observed before and after filtration. In all cases, reductions in turbidity and color levels are seen when polyelectrolytes are used. The best results are achieved using a relation of ≈ 0.02 g O3/g TOC.

We have studied the relationship between the effect of epidermal growth factor (EGF) on glycogen metabolism and its effect on glycolysis, in rat hepatocyte suspensions. Although 10 nM glucagon or 10 microM adrenaline increased glycogen degradation by more than 120%, 10 nM EGF increased glycogenolysis by less than 20% in hepatocytes incubated in glucose-free medium. Both glucagon and adrenaline increased phosphorylase a activity by more than 130%; EGF increased this activity by about 30%. Under basal conditions, 65% of the glucosyl residues were released as free glucose and about 30% ended up as C3 molecules (lactate and pyruvate). Both glucagon and adrenaline decreased the proportion of glucosyl units that rendered glycolysis end-products (to 2% for glucagon and 6% for adrenaline) and increased the proportion that ended up as free glucose (to 94% and 88% of the glucosyl residues for glucagon and adrenaline respectively). EGF increased the production of both free glucose and lactate+pyruvate, but the proportion of glucosyl residues that ended up as free glucose or glycolysis end-products was unchanged. In glycogen-depleted hepatocytes incubated in the presence of 25 mM glucose, EGF affected neither glycogen deposition nor glycolysis. EGF increased cytosolic free Ca2+, and neomycin decreased both the Ca2+ signal and the glycogenolytic effect. In conclusion, our results indicate that the effect of EGF on glycolysis is secondary to the Ca(2+)-mediated stimulation of glycogenolysis in rat hepatocyte suspensions.

The lipoprotein lipase activity in the liver of neonatal (1 day old) rats was about 3 times that in the liver of adult rats. Perfusion of the neonatal liver with collagenase decreased the tissue-associated activity by 77%. When neonatal-rat liver cells were dispersed, hepatocyte-enriched (fraction I) and haemopoietic-cell-enriched (fraction II) populations were obtained. The lipoprotein lipase activity in fraction I was 7 times that in fraction II. On the basis of those activities and the proportion of both cell types in either fraction, it was estimated that hepatocytes contained most, if not all, the lipoprotein lipase activity detected in collagenase-perfused neonatal-rat livers. From those calculations it was also concluded that haemopoietic cells did not contain lipoprotein lipase activity. When the hepatocyte-enriched cell population was incubated at 25 degrees C for up to 3 h, a slow but progressive release of enzyme activity to the incubation medium was found. However, the total activity (cells + medium) did not significantly change through the incubation period. Cycloheximide produced a time-dependent decrease in the cell-associated activity. Heparin increased the amount of lipoprotein lipase activity released to the medium. Because the cell-associated activity was unchanged, heparin also produced a time-dependent increase in the total activity. In those cells incubated with heparin, cycloheximide did not affect the initial release of lipoprotein lipase activity to the medium, but blocked further release. The cell-associated activity was also decreased by the presence of cycloheximide in those cells. It is concluded that neonatal-rat hepatocytes synthesize active lipoprotein lipase.

Heparin (5 units/ml) produced a rapid (5-10 min) release of lipoprotein lipase (LPL) into the incubation medium of cardiac myocytes. Preincubation of myocytes for 30 min with 0.01-10 microM-isoprenaline, 100 microM-forskolin or 500 microM-8-(4-chlorophenylthio)adenosine 3′,5′-cyclic monophosphate did not increase heparin-releasable LPL activity. Incubation with isoprenaline also did not change cellular LPL activity, even though the catecholamine did increase the phosphorylase a activity ratio.

The administration of Intralipid to starved adult rats induces the appearance of lipoprotein lipase (LPL)-like activity in the liver, whereas the so-called hepatic triacylglycerol lipase is unaffected. This LPL-like activity is eluted by 1.5 M-NaCl from heparin-Sepharose columns. This partially purified fraction is inhibited by 1.0 M-NaCl (91%) and by 1.0 mg of protamine sulphate/ml (79%), whereas it is stimulated 69-fold by the presence of 8.0 micrograms of apolipoprotein C-II/ml and inhibited by anti-LPL antibodies. We conclude that Intralipid administration induces the appearance of LPL activity in livers of starved adult rats. Its possible origin is discussed.

Based on high-resolution (R≈ 42   000 to 48   000) and high signal-to-noise (S/N≈ 50 to 150) spectra obtained with UVES/VLT, we present detailed elemental abundances (O, Na, Mg, Al, Si, Ca, Ti, Cr, Fe, Ni, Zn, Y, and Ba) and stellar ages for 12 new microlensed dwarf and subgiant stars in the Galactic bulge. Including previous microlensing events, the sample of homogeneously analysed bulge dwarfs has now grown to 26. The analysis is based on equivalent width measurements and standard 1-D LTE MARCS model stellar atmospheres. We also present NLTE Li abundances based on line synthesis of the 7Li line at 670.8 nm. The results from the 26 microlensed dwarf and subgiant stars show that the bulge metallicity distribution (MDF) is double-peaked; one peak at  [Fe/H]  ≈ −0.6 and one at  [Fe/H]  ≈  + 0.3, and with a dearth of stars around solar metallicity. This is in contrast to the MDF derived from red giants in Baade’s window, which peaks at this exact value. A simple significance test shows that it is extremely unlikely to have such a gap in the microlensed dwarf star MDF if the dwarf stars are drawn from the giant star MDF. To resolve this issue we discuss several possibilities, but we can not settle on a conclusive solution for the observed differences. We further find that the metal-poor bulge dwarf stars arepredominantly old with ages greater than 10 Gyr, while the metal-rich bulge dwarf stars show a wide range of ages. The metal-poor bulge sample is very similar to the Galactic thick disk in terms of average metallicity, elemental abundance trends, and stellar ages. Speculatively, the metal-rich bulge population might be the manifestation of the inner thin disk. If so, the two bulge populations could support the recent findings, based on kinematics, that there are no signatures of a classical bulge and that the Milky Way is a pure-disk galaxy. Also, recent claims of a flat IMF in the bulge based on the MDF of giant stars may have to be revised based on the MDF and abundance trends probed by our microlensed dwarf stars.

We present a re-analysis of the Geneva-Copenhagen survey, which benefits from the infrared flux method to improve the accuracy of the derived stellar effective temperatures and uses the latter to build a consistent and improved metallicity scale. Metallicities are calibrated on high-resolution spectroscopy and checked against four open clusters and a moving group, showing excellent consistency. The new temperature and metallicity scales provide a better match to theoretical isochrones, which are used for a Bayesian analysis of stellar ages. With respect to previous analyses, our stars are on average 100 K hotter and 0.1 dex more metal rich, which shift the peak of the metallicity distribution function around the solar value. From Strömgren photometry we are able to derive for the first time a proxy for  [α/Fe]  abundances, which enables us to perform a tentative dissection of the chemical thin and thick disc. We find evidence for the latter being composed of an old, mildly but systematically alpha-enhanced population that extends to super solar metallicities, in agreement with spectroscopic studies. Our revision offers the largest existing kinematically unbiased sample of the solar neighbourhood that contains full information on kinematics, metallicities, and ages and thus provides better constraints on the physical processes relevant in the build-up of the Milky Way disc, enabling a better understanding of the Sun in a Galactic context.

Aims.Solar colors have been determined on the uvby–βphotometric system to test absolute solar fluxes, to examine colors predicted by model atmospheres as a function of stellar parameters (Teff, log g, [Fe/H]), and to probe zero-points of Teffand metallicity scales.

Recent studies have shown that the elemental abundances in the Sun are anomalous when compared to most (about 85%) nearby solar twin stars. Compared to its twins, the Sun exhibits a deficiency of refractory elements (those with condensation temperatures TC≳ 900 K) relative to volatiles (TC≲ 900 K). This finding is speculated to be a signature of the planet formation that occurred more efficiently around the Sun compared with the majority of solar twins. Furthermore, within this scenario, it seems more likely that the abundance patterns found are specifically related to the formation of terrestrial planets. In this work we analyze abundance results from six large independent stellar abundance surveys to determine whether they confirm or reject this observational finding. We show that the elemental abundances derived for solar analogs in these six studies are consistent with the TCtrend suggested as a planet formation signature. The same conclusion is reached when those results are averaged heterogeneously. We also investigate the dependency of the abundances with first ionization potential (FIP), which correlates well with TC. A trend with FIP would suggest a different origin for the abundance patterns found, but we show that the correlation with TCis statistically more significant. We encourage similar investigations of metal-rich solar analogs and late F-type dwarf stars, for which the hypothesis of a planet formation signature in the elemental abundances makes very specific predictions. Finally, we examine a recent paper that claims that the abundance patterns of two stars hosting super-Earth like planets contradict the planet formation signature hypothesis. Instead, we find that the chemical compositions of these two stars are fully compatible with our hypothesis.

We have determined precise stellar parameters and lithium abundances in a sample of 117 stars with basic properties very similar to the Sun. This sample selection reduces biasing effects and systematic errors in the analysis. We estimate the ages of our sample stars mainly from isochrone fitting but also from measurements of rotation period and X-ray luminosity and test the connection between lithium abundance, age, and stellar parameters. We find strong evidence for increasing lithium depletion with age. Our sample includes 14 stars that are known to host planets and it does not support recent claims that planet-host stars have experienced more lithium depletion than stars without planets. We find the solar lithium abundance normal for a star of its age, mass, and metallicity. Furthermore, we analyze published data for 82 stars that were reported to support an enhanced lithium depletion in planet hosts. We show that those stars in fact follow an age trend very similar to that found with our sample and that the presence of giant planets is not related to low lithium abundances. Finally, we discuss the systematic biases that led to the incorrect conclusion of an enhanced lithium depletion in planet-host stars.

We present NLTE Li abundances for 88 stars in the metallicity range -3.5 <[Fe/H] <-1.0. The effective temperatures are based on the infrared flux method with improved $E(B-V)$values obtained mostly from interstellar $\ion{Na}{i}$D lines. The Li abundances were derived through MARCS models and high-quality UVES+VLT, HIRES+Keck and FIES+NOT spectra, and complemented with reliable equivalent widths from the literature. The less-depleted stars with [Fe/H] <-2.5 and [Fe/H] >-2.5 fall into two well-defined plateaus of ALi=2.18 (σ= 0.04) and ALi=2.27 (σ= 0.05), respectively. We show that the two plateaus are flat, unlike previous claims for a steep monotonic decrease in Li abundances with decreasing metallicities. At all metallicities we uncover a fine-structure in the Li abundances of Spite plateau stars, which we trace to Li depletion that depends on both metallicity and mass. Models including atomic diffusion and turbulent mixing seem to reproduce the observed Li depletion assuming a primordial Li abundance ALi= 2.64, which agrees well with current predictions (ALi= 2.72) from standard Big Bang nucleosynthesis. Adopting the Kurucz overshooting model atmospheres increases the Li abundance by +0.08 dex to ALi= 2.72, which perfectly agrees with BBN+WMAP.

Context. The formation and evolution of the Galactic bulge and its relationship with the other Galactic populations is still poorly understood. Aims. To establish the chemical differences and similarities between the bulge and other stellar populations, we performed an elemental abundance analysis of α- (O, Mg, Si, Ca, and Ti) and Z-odd (Na and Al) elements of red giant stars in the bulge as well as of local thin disk, thick disk and halo giants. Methods. We use high-resolution optical spectra of 25 bulge giants in Baade's window and 55 comparison giants (4 halo, 29 thin disk and 22 thick disk giants) in the solar neighborhood. All stars have similar stellar parameters but cover a broad range in metallicity (-1.5 < [Fe/H] < +0.5). A standard 1D local thermodynamic equilibrium analysis using both Kurucz and MARCS models yielded the abundances of O, Na, Mg, Al, Si, Ca, Ti and Fe. Our homogeneous and differential analysis of the Galactic stellar populations ensured that systematic errors were minimized.Results. We confirm the well-established differences for [α/Fe] at a given metallicity between the local thin and thick disks. For all the elements investigated, we find no chemical distinction between the bulge and the local thick disk, in agreement with our previous study of C, N and O but in contrast to other groups relying on literature values for nearby disk dwarf stars. For -1.5 < [Fe/H] < -0.3 exactly the same trend is followed by both the bulge and thick disk stars, with a star-to-star scatter of only 0.03 dex. Furthermore, both populations share the location of the knee in the [α/Fe] vs. [Fe/H] diagram. It still remains to be confirmed that the local thick disk extends to super-solar metallicities as is the case for the bulge. These are the most stringent constraints to date on the chemical similarity of these stellar populations. Conclusions. Our findings suggest that the bulge and local thick disk stars experienced similar formation timescales, star formation rates and initial mass functions, confirming thus the main outcomes of our previous homogeneous analysis of [O/Fe] from infrared spectra for nearly the same sample. The identical α-enhancements of thick disk and bulge stars may reflect a rapid chemical evolution taking place before the bulge and thick disk structures we see today were formed, or it may reflect Galactic orbital migration of inner disk/bulge stars resulting in stars in the solar neighborhood with thick-disk kinematics.

Various effective temperature scales have been proposed over the years. Despite much work and the high internal precision usually achieved, systematic differences of order 100 K (or more) among various scales are still present. We present an investigation based on the infrared flux method aimed at assessing the source of such discrepancies and pin down their origin. We break the impasse among different scales by using a large set of solar twins, stars which are spectroscopically and photometrically identical to the Sun, to set the absolute zero point of the effective temperature scale to within few degrees. Our newly calibrated, accurate and precise temperature scale applies to dwarfs and subgiants, from super-solar metallicities to the most metal-poor stars currently known. At solar metallicities our results validate spectroscopic effective temperature scales, whereas for $\mathrm{[Fe/H]}\la -2.5$our temperatures are roughly 100 K hotter than those determined from model fits to the Balmer lines and 200 K hotter than those obtained from the excitation equilibrium of Fe lines. Empirical bolometric corrections and useful relations linking photometric indices to effective temperatures and angular diameters have been derived. Our results take full advantage of the high accuracy reached in absolute calibration in recent years and are further validated by interferometric angular diameters and space based spectrophotometry over a wide range of effective temperatures and metallicities.

We present a study of some properties of transport in small-world and scale-free networks. Particularly, we compare two types of transport: subject to friction (electrical case) and in the absence of friction (maximum flow). We found that in clustered networks based on the Watts–Strogatz (WS) model, for both transport types the small-world configurations exhibit the best trade-off between local and global levels. For non-clustered WS networks the local transport is independent of the rewiring parameter, while the transport improves globally. Moreover, we analyzed both transport types in scale-free networks considering tendencies in the assortative or disassortative mixing of nodes. We construct the distribution of the conductance G and flow F to evaluate the effects of the assortative (disassortative) mixing, finding that for scale-free networks, as we introduce different levels of the degree–degree correlations, the power-law decay in the conductances is altered, while for the flow, the power-law tail remains unchanged. In addition, we analyze the effect on the conductance and the flow of the minimum degree and the shortest path between the source and destination nodes, finding notable differences between these two types of transport. [ABSTRACT FROM AUTHOR]