Novel fibrin clot components : identification, characterization and function

The main goal of blood coagulation is to diminish blood loss and to support vessel damage repair. The initial step in primary hemostasis is the adhesion of platelets to the exposed subendothelial extracellular matrix which contains several adhesive macromolecules such as collagen, von Willebrand factor (vWF), laminin, fibronectin and thrombospondin. These adhesive macromolecules are ligands for different platelet-surface receptors. Upon binding, platelets can be activated by different signal transduction pathways. Platelet adhesion and activation is followed by platelet aggregation, which involves fibrinogen binding to an integrin on the surface of the activated platelet. Secondary hemostasis is initiated by exposure of tissue factor (TF) to blood by endothelial damage. TF forms a complex with coagulation factor VII which activates factor IX and factor X. Activated factor X (FXa) forms the prothrombinase complex together with activated factor V (FVa) on a phospholipid membrane surface, which is provided by, for example, activated platelets and microparticles, and which converts prothrombin into thrombin. Thrombin can amplify its own generation by activating FXI, and FXIa activates FIX, that together with activated FVIII forms more FX. Thrombin is an important enzyme that cleaves fibrinogen into fibrin monomer. Fibrin monomers polymerize and the resulting network is stabilized by factor XIIIa-catalyzed cross-linking. This tight fibrin network together with activated platelets occludes the site of vascular injury. After its formation, the clot will retract. The speed and degree of clot retraction are proportional to the number of platelets. Neither the significance of in vivo clot retraction for hemostasis as well as the mechanism of clot retraction are well understood. Retraction may improve the mechanical stability of clots. To maintain a balance, the coagulation pathway is inhibited by several inhibitors. Tissue factor pathway inhibitor (TFPI) inhibits the TF-induced coagulation firstly by binding to FXa. Secondly, this TFPI-FXa complex binds to the TF-FVIIa complex resulting in the formation of an inactive quaternary complex. TFPI can also inhibit the initiation phase of coagulation in one step by binding to activated FX that is not yet released from its complex with TF-FVIIa. Thrombin is directly inhibited by the serine protease inhibitor antithrombin as well as heparin cofactor II. Thrombin can also bind to thrombomodulin and form a complex that activates protein C. Activated protein C (APC), with its cofactor protein S, has anticoagulant properties through proteolytic inactivation of factors Va and VIIIa

Vegetación de Doñana (Huelva, España)

Monografía fitosociológica de la vegetación de la Reserva Biológica y del Parque Nacional de Doñana (Huelva, España). En base a la publicación de 461 inventarios y 25 sin inventarios se describen 70 asociaciones pertenecientes a 28 clases de vegetación, así como se dan a conocer cinco sinasociaciones. De cada asociación se aportan datos florísticos, ecológicos, estructurales, corológicos y taxonómicos, y en muchos casos sus relaciones con las asociaciones geovicarias. Además de numerosos esquemas catenales y dinámicos de la vegetación, se incluye una lista de los sintáxones y un catálogo alfabético de las plantas vasculares de Doñana y de las comentadas en el texto.Phytosociological monograph on the Doñana vegetation (Biological Reserve and National Park). Based on 461 releves and 25 synreleves, 70 associations, belonging to 28 phytosociological classes, are described. From each association floristical, ecological, structural, chorological, taxonomical data are given. The relationships with other geovicariant associations are also pointed out. Additionally, a great number of catenas and dinamical schemes of the vegetation have been drawn. Finally a checklist of the sintaxa and of the vascular plants is [email protected]

bRing: An observatory dedicated to monitoring the β\beta Pictoris b Hill sphere transit

Aims. We describe the design and first light observations from the $\beta$ Pictoris b Ring ("bRing") project. The primary goal is to detect photometric variability from the young star $\beta$ Pictoris due to circumplanetary material surrounding the directly imaged young extrasolar gas giant planet \bpb. Methods. Over a nine month period centred on September 2017, the Hill sphere of the planet will cross in front of the star, providing a unique opportunity to directly probe the circumplanetary environment of a directly imaged planet through photometric and spectroscopic variations. We have built and installed the first of two bRing monitoring stations (one in South Africa and the other in Australia) that will measure the flux of $\beta$ Pictoris, with a photometric precision of $0.5\%$ over 5 minutes. Each station uses two wide field cameras to cover the declination of the star at all elevations. Detection of photometric fluctuations will trigger spectroscopic observations with large aperture telescopes in order to determine the gas and dust composition in a system at the end of the planet-forming era. Results. The first three months of operation demonstrate that bRing can obtain better than 0.5\% photometry on $\beta$ Pictoris in five minutes and is sensitive to nightly trends enabling the detection of any transiting material within the Hill sphere of the exoplanet

Na I and Hα\alpha absorption features in the atmosphere of MASCARA-2b/KELT-20b

We have used the HARPS-North high resolution spectrograph ($\mathcal{R}$=115 000) at TNG to observe one transit of the highly irradiated planet MASCARA-2b/KELT-20b. Using only one transit observation, we are able to clearly resolve the spectral features of the atomic sodium (Na I) doublet and the H$\alpha$ line in its atmosphere, measuring absorption depths of 0.17$\pm$0.03$\%$ and 0.59$\pm$0.08$\%$ for a 0.75 $\AA$ passband, respectively. These absorptions are corroborated with the transmission measured from their respective transmission light curves, which show a large Rossiter-McLaughlin effect. In case of H$\alpha$, this absorption corresponds to an effective radius of $R_{\lambda}/R_P$=1.20$\pm$0.04. While the S/N of the final transmission spectrum is not sufficient to adjust different temperature profiles to the lines, we find that higher temperatures than the equilibrium are needed to explain the lines contrast. Particularly, we find that the Na I lines core require a temperature of T=4210$\pm$180K and that H$\alpha$ requires T=4330$\pm$520K. MASCARA-2b, like other planets orbiting A-type stars, receives a large amount of UV energy from its host star. This energy excites the atomic hydrogen and produces H$\alpha$ absorption, leading to the expansion and abrasion of the atmosphere. The study of other Balmer lines in the transmission spectrum would allow the determination of the atmospheric temperature profile and the calculation of the lifetime of the atmosphere. In the case of MASCARA-2b, residual features are observed in the H$\beta$ and H$\gamma$ lines, but they are not statistically significant. More transit observations are needed to confirm our findings in Na I and H$\alpha$, and to build up enough S/N to explore the presence of H$\beta$ and H$\gamma$ planetary absorptions.Comment: 14 pages, 12 figure

Flow, viscoelastic and masticatory properties of tailor made thickened pea cream for people with swallowing problems

[EN] This study evaluated the flow, viscoelastic and masticatory properties of tailor made pea cream using different hydrocolloids, and the potential effect that saliva could have while chewing. The creams thickened with pectin, carboxymethyl cellulose, tara gum and konjac gum showed the weakest internal gel structure with highest values of loss tangent at 1Hz (0.49 +/- 0.07), slope of log elastic modulus versus log frequency (0.34 +/- 0.05) and maximum capacitance (0.07 +/- 0.02 Pa-1). The samples thickened with commercial hydrocolloids were affected the most by the presence of saliva, with a significant reduction in apparent viscosity at 10 s(-1), that ranged from 1500 mPas until 11000 mPas. These results demonstrate that it is possible to optimize the structure of thickened pea cream for dysphagia by using, for example, carboxymethyl cellulose, tara gum and konjac gum, because they provide a greater viscous component, and, therefore, a bolus that is more easy to swallow.The authors thank the "Ministerio Espanol de Ciencia e Innovaci.on" for the financial support provided through the RTI2018-098842-B-I00 Project.Talens Oliag, P.; Castells, ML.; Verdú, S.; Barat Baviera, JM.; Grau Meló, R. (2021). Flow, viscoelastic and masticatory properties of tailor made thickened pea cream for people with swallowing problems. Journal of Food Engineering. 292:1-10. https://doi.org/10.1016/j.jfoodeng.2020.110265S11029

Use of hyperspectral transmittance imaging to evaluate the internal quality of nectarines

[EN] The internal quality of nectarines (Prunus persica L. Batsch var. nucipersica) cv. 'Big Top' (yellow flesh) and 'Magique' (white flesh) has been inspected using hyperspectral transmittance imaging. Hyperspectral images of intact fruits were acquired in the spectral range of 630-900 nm using transmittance mode during their ripening under controlled conditions. The detection of split pit disorder and classification according to an established firmness threshold were performed using PLS-DA. The prediction of the Internal Quality Index (IQI) related to ripeness was performed using PLS-R. The most important variables were selected using interval-PLS. As a result, an accuracy of 94.7% was obtained in the detection of fruits with split pit of the 'Big Top' cultivar. Accuracies of 95.7% and 94.6% were achieved in the classification of the 'Big Top' and 'Magique' cultivars, respectively, according to the firmness threshold. The internal quality was predicted through the IQI with R-2 values of 0.88 and 0.86 for the two cultivars. The results obtained indicate the great potential of hyperspectral transmittance imaging for the assessment of the internal quality of intact nectarines.This work was partially funded by INIA and FEDER funds through project RTA2015-00078-00-00. Sandra Munera thanks INIA for the FPI-INIA grant num. 43 (CPR2014-0082), partially supported by European Union FSE funds.Munera, S.; Blasco Ivars, J.; Amigo, J.; Cubero-García, S.; Talens Oliag, P.; Aleixos Borrás, MN. (2019). Use of hyperspectral transmittance imaging to evaluate the internal quality of nectarines. Biosystems Engineering. 182:54-64. https://doi.org/10.1016/j.biosystemseng.2019.04.001S546418

Data calibration for the MASCARA and bRing instruments

Aims: MASCARA and bRing are photometric surveys designed to detect variability caused by exoplanets in stars with $m_V < 8.4$. Such variability signals are typically small and require an accurate calibration algorithm, tailored to the survey, in order to be detected. This paper presents the methods developed to calibrate the raw photometry of the MASCARA and bRing stations and characterizes the performance of the methods and instruments. Methods: For the primary calibration a modified version of the coarse decorrelation algorithm is used, which corrects for the extinction due to the earth's atmosphere, the camera transmission, and intrapixel variations. Residual trends are removed from the light curves of individual stars using empirical secondary calibration methods. In order to optimize these methods, as well as characterize the performance of the instruments, transit signals were injected in the data. Results: After optimal calibration an RMS scatter of 10 mmag at $m_V \sim 7.5$ is achieved in the light curves. By injecting transit signals with periods between one and five days in the MASCARA data obtained by the La Palma station over the course of one year, we demonstrate that MASCARA La Palma is able to recover 84.0, 60.5 and 20.7% of signals with depths of 2, 1 and 0.5% respectively, with a strong dependency on the observed declination, recovering 65.4% of all transit signals at $\delta > 0^\circ$ versus 35.8% at $\delta < 0^\circ$. Using the full three years of data obtained by MASCARA La Palma to date, similar recovery rates are extended to periods up to ten days. We derive a preliminary occurrence rate for hot Jupiters around A-stars of ${>} 0.4 \%$, knowing that many hot Jupiters are still overlooked. In the era of TESS, MASCARA and bRing will provide an interesting synergy for finding long-period (${>} 13.5$ days) transiting gas-giant planets around the brightest stars.Comment: 18 pages, 17 figures, accepted for publication in A&

Comparison of the influence of corneo-scleral and scleral lenses on ocular surface and tear film metrics in a presbyopic population

PURPOSE: To assess and compare the effect of the corneo-scleral lenses (C-ScL) and scleral lenses (ScL) on tear film parameters and central corneal thickness (CCT) in healthy presbyopic subjects. METHODS: Thirty subjects wore two contact lenses (CLs), randomly assigned, of neutral power, but of different diameters, 12.7mm (C-ScL) and 18mm (ScL) and being equal in the others parameters: material (HS100) and centre thickness (0.29mm). At baseline, 20min after insertion and at 8h, the tear meniscus area (TMA) and CCT was measured (with optical coherence tomography) as well as tear osmolarity. RESULTS: TMA revealed statistical differences for both lenses at 20min (p<0.001), and also at 8h (p=0.003), being greater for the C-ScL. CCT showed statistical differences for both lenses at 20min (p=0.002), and also at 8h (p=0.001), being lower for the C-ScL. Osmolarity did not reveal statistical differences at 20min (p=0.29), while it was statistically different at 8h (p=0.03), being lower for the C-ScL. CONCLUSIONS: C-ScL lead to a lesser reduction in the TMA and a lower induced hypoxic stress than the ScL. Osmolarity levels remained within normal values across the day with no clinical difference between lenses. Both designs can represent a good optical platform for correcting presbyopia as well as protecting the ocular surface by vaulting the cornea

Potential of VIS-NIR hyperspectral imaging and chemometric methods to identify similar cultivars of nectarine

[EN] Product inspection is essential to ensure good quality and to avoid fraud. New nectarine cultivars with similar external appearance but different physicochemical properties may be mixed in the market, causing confusion and rejection among consumers, and consequently affecting sales and prices. Hyperspectral reflectance imaging in the range of 450¿1040 nm was studied as a non-destructive method to differentiate two cultivars of nectarines with a very similar appearance but different taste. Partial least squares discriminant analysis (PLS-DA) was used to develop a prediction model to distinguish intact fruits of the cultivars using pixel-wise and mean spectrum approaches, and then the model was projected onto the complete surface of fruits allowing visual inspection. The results indicated that mean spectrum of the fruit was the most accurate method, a correct discrimination rate of 94% being achieved. Wavelength selection reduced the dimensionality of the hyperspectral images using the regression coefficients of the PLS-DA model. An accuracy of 96% was obtained by using 14 optimal wavelengths, whereas colour imaging and a trained inspection panel achieved a rate of correct classification of only 57% of the fruits.This work was partially funded by INIA and FEDER funds through project RTA2015-00078-00-00. Sandra Munera thanks INIA for the FPI-INIA grant num. 43 (CPR2014-0082), partially supported by European Union FSE funds. The authors wish to thank Fruits de Ponent (Lleida) for providing the fruit.Munera-Picazo, S.; Amigo, JM.; Aleixos Borrás, MN.; Talens Oliag, P.; Cubero-García, S.; Blasco Ivars, J. (2018). Potential of VIS-NIR hyperspectral imaging and chemometric methods to identify similar cultivars of nectarine. Food Control. 86:1-10. https://doi.org/10.1016/j.foodcont.2017.10.037S1108