Intercomparison of carbonate chemistry measurements on a cruise in northwestern European shelf seas

Four carbonate system variables were measured in surface waters during a cruise aimed at investigating ocean acidification impacts traversing northwestern European shelf seas in the summer of 2011. High-resolution surface water data were collected for partial pressure of carbon dioxide (pCO2; using two independent instruments) and pH using the total pH scale (pHT), in addition to discrete measurements of total alkalinity and dissolved inorganic carbon. We thus overdetermined the carbonate system (four measured variables, two degrees of freedom), which allowed us to evaluate the level of agreement between the variables on a cruise whose main aim was not intercomparison, and thus where conditions were more representative of normal working conditions. Calculations of carbonate system variables from other measurements generally compared well with direct observations of the same variables (Pearson’s correlation coefficient always greater than or equal to 0.94; mean residuals were similar to the respective accuracies of the measurements). We therefore conclude that four of the independent data sets of carbonate chemistry variables were of high quality. A diurnal cycle with a maximum amplitude of 41 μatm was observed in the difference between the pCO2 values obtained by the two independent analytical pCO2 systems, and this was partly attributed to irregular seawater flows to the equilibrator and partly to biological activity inside the seawater supply and one of the equilibrators. We discuss how these issues can be addressed to improve carbonate chemistry data quality on future research cruises

Spectroscopic characterisation of CARMENES target candidates from FEROS, CAFE and HRS high-resolution spectra

CARMENES (Calar Alto high-Resolution search for M dwarfs with Exoearths with Near-infrared and optical Echelle Spectrographs) started a new planet survey on M-dwarfs in January this year. The new high-resolution spectrographs are operating in the visible and near-infrared at Calar Alto Observatory. They will perform high-accuracy radial-velocity measurements (goal 1 m s-1) of about 300 M-dwarfs with the aim to detect low-mass planets within habitable zones. We characterised the candidate sample for CARMENES and provide fundamental parameters for these stars in order to constrain planetary properties and understand star-planet systems. Using state-of-the-art model atmospheres (PHOENIX-ACES) and chi2-minimization with a downhill-simplex method we determine effective temperature, surface gravity and metallicity [Fe/H] for high-resolution spectra of around 480 stars of spectral types M0.0-6.5V taken with FEROS, CAFE and HRS. We find good agreement between the models and our observed high-resolution spectra. We show the performance of the algorithm, as well as results, parameter and spectral type distributions for the CARMENES candidate sample, which is used to define the CARMENES target sample. We also present first preliminary results obtained from CARMENES spectra

On the zeroth-order Hamiltonian for CASPT2 calculations of spin crossover compounds

Complete active space self-consistent field theory (CASSCF) calculations and subsequent second-order perturbation theory treatment (CASPT2) are discussed in the evaluation of the spin-states energy difference (ΔHelec) of a series of seven spin crossover (SCO) compounds. The reference values have been extracted from a combination of experimental measurements and DFT  +  U calculations, as discussed in a recent article (Vela et al., Phys Chem Chem Phys 2015, 17, 16306). It is definitely proven that the critical IPEA parameter used in CASPT2 calculations of ΔHelec, a key parameter in the design of SCO compounds, should be modified with respect to its default value of 0.25 a.u. and increased up to 0.50 a.u. The satisfactory agreement observed previously in the literature might result from an error cancellation originated in the default IPEA, which overestimates the stability of the HS state, and the erroneous atomic orbital basis set contraction of carbon atoms, which stabilizes the LS states

Effects of parasite and historic driven selection on the diversity and structure of a MHC-II gene in a small mammal species (Peromyscus leucopus) undergoing range expansion.

Abstract Genetic diversity may decrease from the centre to the margin of a species distribution range due to neutral stochastic processes. Selection may also alter genetic diversity in non-neutral markers, such as genes associated with the immune system. Both neutral processes and selection on the immune system are thus expected to affect the spatial distribution of such markers, but the relative strength of each has been scarcely studied. Here, we compared the diversity of a neutral marker (mitochondrial cytochrome b)and a selected marker (DRB gene from the MHC-II), in eastern-North American populations of white-footed mice (Peromyscus leucopus), a species known for its role of main reservoir of the Lyme disease. We observed distinct phylogeographic patterns with these two markers, which may be the result of selection pressure acting upon the DRB gene. As predicted by the central marginal hypothesis, we observed a loss of neutral genetic diversity toward the margin of the species distribution. A decrease in diversity was also observed for the DRB gene, likely due to genetic drift and positive selection operated by helminth parasites. Such a loss in genetic diversity at the range margin may slow down the ongoing expansion of P. leucopus, by counterbalancing the effect of global warming on the mouse survival at higher latitude

Downscaling conventional methods for the spectrophotometric study of metal ions complexation

One of the major challenges in a chemistry laboratory is the continuous search for a more sustainable practice, following Green Chemistry guidelines. The present work was devoted to the development of a high throughput and miniaturized strategy for chemistry conventional protocols for the study of complex formation of metallic compounds. In this scenario, the spectrophotometric calibration curve method and the Job’s method of continuous variation were adapted to the microplate format. This work involved several metal ions (Co(II), Cu (II), Cd(II), Fe(III), Mn(II), Ni(II), Pb(II) and Zn(II)) and two different complexing agents, 2-Carboxy-2′-hydroxy- 5′-sulfoformazyl-benzene (Zincon) and 4-(2-Pyridylazo)resorcinol (PAR). Microplate assays demonstrated to be useful tools for the investigation of the equilibrium process of metal ion complexes. Additionally, these methods involved lower volume of reagents and the analysis throughput was augmented when compared with conventional strategiesinfo:eu-repo/semantics/publishedVersio

The CARMENES search for exoplanets around M dwarfs - Photospheric parameters of target stars from high-resolution spectroscopy

The new CARMENES instrument comprises two high-resolution and high-stability spectrographs that are used to search for habitable planets around M dwarfs in the visible and near-infrared regime via the Doppler technique. Characterising our target sample is important for constraining the physical properties of any planetary systems that are detected. The aim of this paper is to determine the fundamental stellar parameters of the CARMENES M-dwarf target sample from high-resolution spectra observed with CARMENES. We also include several M-dwarf spectra observed with other high-resolution spectrographs, that is CAFE, FEROS, and HRS, for completeness. We used a {chi}^2 method to derive the stellar parameters effective temperature T_eff, surface gravity log g, and metallicity [Fe/H] of the target stars by fitting the most recent version of the PHOENIX-ACES models to high-resolution spectroscopic data. These stellar atmosphere models incorporate a new equation of state to describe spectral features of low-temperature stellar atmospheres. Since T_eff, log g, and [Fe/H] show degeneracies, the surface gravity is determined independently using stellar evolutionary models. We derive the stellar parameters for a total of 300 stars. The fits achieve very good agreement between the PHOENIX models and observed spectra. We estimate that our method provides parameters with uncertainties of {sigma} T_eff = 51 K, {sigma} log g = 0.07, and {sigma} [Fe/H] = 0.16, and show that atmosphere models for low-mass stars have significantly improved in the last years. Our work also provides an independent test of the new PHOENIX-ACES models, and a comparison for other methods using low-resolution spectra. In particular, our effective temperatures agree well with literature values, while metallicities determined with our method exhibit a larger spread when compared to literature results

Luxaciones de rodilla: revisión de 11 casos

La luxación de rodilla es una entidad poco frecuente. El tratamiento incorrecto de esta lesión conlleva graves consecuencias cuando existen lesiones vasculares que amenazan la supervivencia de la extremidad afecta. Objetivo . analizar el manejo en urgencias, tratamiento definitivo, complicaciones y resultados funcionales en los pacientes diagnosticados de luxación de rodilla. Material y Métodos . Realizamos un estudio retrospectivo de 11 pacientes tratados en nuestro centro con diagnostico de luxación de rodilla entre junio del 2007 y febrero del 2013. Empleamos el Lysholm Score en la evaluación clínica. Resultados . En 8 de los 11 pacientes el tratamiento fue de manera conservadora. En los 3 pacientes intervenidos se optó por una reconstrucción del ligamento cruzado anterior mediante plastia HTH. Los pacientes intervenidos obtuvieron mejor resultado funcional en relación con los no operados (91 puntos frente a 58). Conclusiones . Es fundamental conocer los principios básicos de actuación y tratamiento debido a las complicaciones potenciales que asocia.Knee dislocation is a rare entity. Improper treatment of this injury has serious consequences when vascular lesions that threaten the survival of the affected limb occur. Objective . To analyse the handling emergencies, definitive treatment, complications and functional outcomes in patients diagnosed with knee dislocation. Materials and methods . A retrospective study of 11 patients admitted to our hospital from June 2007 to February 2013 diagnosed with knee dislocation was performed. Clinical evaluation was carried out using the Lysholm score. Results . Eight out of the 11 patients were treated conservatively. Surgical reconstruction of the anterior cruciate ligament plasty with HTH technique was used in three patients. Surgically-treated patients had better functional outcome compared to the non-operated (91 points versus 58). Conclusions . It is essential to know the basic principles of actuation and treatment because of the potential complications associate

Influência da época do ano e das diferentes concentrações de ácido naftaleno acético (NAA) no enraizamento de Mikania micrantha Kunth.

Organizado por Patricia Póvoa de Mattos, Celso Garcia Auer, Rejane Stumpf Sberze, Katia Regina Pichelli e Paulo César Botosso