El uso de rúbricas para evaluar el progreso de los estudiantes y proporcionarles el feedback en la producción escrita en inglés

Memoria ID-123. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2018-2019

One-dimensional Convolutional Neural Networks for Detecting Transiting Exoplanets

The transit method is one of the most relevant exoplanet detection techniques, which consists of detecting periodic eclipses in the light curves of stars. This is not always easy due to the presence of noise in the light curves, which is induced, for example, by the response of a telescope to stellar flux. For this reason, we aimed to develop an artificial neural network model that is able to detect these transits in light curves obtained from different telescopes and surveys. We created artificial light curves with and without transits to try to mimic those expected for the extended mission of the Kepler telescope (K2) in order to train and validate a 1D convolutional neural network model, which was later tested, obtaining an accuracy of 99.02 % and an estimated error (loss function) of 0.03. These results, among others, helped to confirm that the 1D CNN is a good choice for working with non-phased-folded Mandel and Agol light curves with transits. It also reduces the number of light curves that have to be visually inspected to decide if they present transit-like signals and decreases the time needed for analyzing each (with respect to traditional analysis)

"Snorkelling" vs. "diving" in mixed micelles probed by means of a molecular bathymeter

[EN] A photoactive bathymeter based on a carboxylic acid moiety covalently linked to a signalling methoxynaphthalene (MNP) fluorophore has been designed to prove the concept of "snorkelling" vs. "diving" in mixed micelles (MM). The carboxylic acid "floats" on the MM surface, while the MNP unit sinks deep in MM. The rate constants of MNP fluorescence quenching by iodide, which remains basically in water, consistently decrease with increasing spacer length, revealing different regions. This is associated with the distance MNP should "dive" in MM to achieve protection from aqueous reactants. Unequivocal proof of the exergonic photoinduced electron transfer was obtained from the UV-visible spectral signature of I-3(-) upon steady-state photolysis. The applicability of the bathymeter was examined upon testing a family of MNP derivatives. The obtained results were validated by comparison with different lipophilicity tests: (i) a modified version of the K-ow partition coefficient and (ii) the retention factor on thin layer chromatography. This concept could potentially be extended to test drugs or pharmacophores exhibiting any photoactive moiety.Financial support from the Spanish Government (SEV-2016-0683), Red RETICS de Investigacion de Reacciones Adversas a Alergenos y Farmacos (RIRAAF), Instituto de Salud Carlos III (RD012/0013, RD16/0006/0030, FIS PI16/01877), VLC-Campus and the Generalitat Valenciana (Prometeo Program) is gratefully acknowledged.Rodríguez Muñiz, GM.; Gomez Mendoza, M.; Nuin Pla, NE.; Andreu Ros, MI.; Marín García, ML.; Miranda Alonso, MÁ. (2017). "Snorkelling" vs. "diving" in mixed micelles probed by means of a molecular bathymeter. Organic & Biomolecular Chemistry. 15(48):10281-10288. https://doi.org/10.1039/c7ob02595eS10281102881548Porter, C. J. H., Trevaskis, N. L., & Charman, W. N. (2007). Lipids and lipid-based formulations: optimizing the oral delivery of lipophilic drugs. Nature Reviews Drug Discovery, 6(3), 231-248. doi:10.1038/nrd2197Hammad, M. ., & Müller, B. . (1998). Increasing drug solubility by means of bile salt–phosphatidylcholine-based mixed micelles. European Journal of Pharmaceutics and Biopharmaceutics, 46(3), 361-367. doi:10.1016/s0939-6411(98)00037-xNagadome, S., Numata, O., Sugihara, G., Sasaki, Y., & Igimi, H. (1995). Solubilization and precipitation of cholesterol in aqueous solution of bile salts and their mixtures. Colloid & Polymer Science, 273(7), 675-680. doi:10.1007/bf00652260Hofmann, A. F. (1999). The Continuing Importance of Bile Acids in Liver and Intestinal Disease. Archives of Internal Medicine, 159(22), 2647. doi:10.1001/archinte.159.22.2647Ding, J., Sun, Y., Li, J., Wang, H., & Mao, S. (2017). Enhanced blood–brain barrier transport of vinpocetine by oral delivery of mixed micelles in combination with a message guider. Journal of Drug Targeting, 25(6), 532-540. doi:10.1080/1061186x.2017.1289541Lasic, D. D. (1992). Mixed micelles in drug delivery. Nature, 355(6357), 279-280. doi:10.1038/355279a0Cheng, L., Kamkaew, A., Sun, H., Jiang, D., Valdovinos, H. F., Gong, H., … Cai, W. (2016). Dual-Modality Positron Emission Tomography/Optical Image-Guided Photodynamic Cancer Therapy with Chlorin e6-Containing Nanomicelles. ACS Nano, 10(8), 7721-7730. doi:10.1021/acsnano.6b03074Lipinski, C. A., Lombardo, F., Dominy, B. W., & Feeney, P. J. (1997). Experimental and computational approaches to estimate solubility and permeability in drug discovery and development settings. Advanced Drug Delivery Reviews, 23(1-3), 3-25. doi:10.1016/s0169-409x(96)00423-1Beaumont, K., Schmid, E., & Smith, D. A. (2005). Oral delivery of G protein-coupled receptor modulators: An explanation for the observed class difference. Bioorganic & Medicinal Chemistry Letters, 15(16), 3658-3664. doi:10.1016/j.bmcl.2005.05.042Al-Abdul-Wahid, M. S., Neale, C., Pomès, R., & Prosser, R. S. (2009). A Solution NMR Approach to the Measurement of Amphiphile Immersion Depth and Orientation in Membrane Model Systems. Journal of the American Chemical Society, 131(18), 6452-6459. doi:10.1021/ja808964eAfri, M., Frimer, A. A., & Cohen, Y. (2004). Active oxygen chemistry within the liposomal bilayer. Chemistry and Physics of Lipids, 131(1), 123-133. doi:10.1016/j.chemphyslip.2004.04.006Cohen, Y., Bodner, E., Richman, M., Afri, M., & Frimer, A. A. (2008). NMR-based molecular ruler for determining the depth of intercalants within the lipid bilayer. Chemistry and Physics of Lipids, 155(2), 98-113. doi:10.1016/j.chemphyslip.2008.07.004Cohen, Y., Afri, M., & Frimer, A. A. (2008). NMR-based molecular ruler for determining the depth of intercalants within the lipid bilayer. Chemistry and Physics of Lipids, 155(2), 114-119. doi:10.1016/j.chemphyslip.2008.07.007Afri, M., Alexenberg, C., Aped, P., Bodner, E., Cohen, S., Ejgenburg, M., … Frimer, A. A. (2014). NMR-based molecular ruler for determining the depth of intercalants within the lipid bilayer. Chemistry and Physics of Lipids, 184, 105-118. doi:10.1016/j.chemphyslip.2014.07.007Afri, M., Naqqash, M. E., & Frimer, A. A. (2011). Using fluorescence to locate intercalants within the lipid bilayer of liposomes, bioliposomes and erythrocyte ghosts. Chemistry and Physics of Lipids, 164(8), 759-765. doi:10.1016/j.chemphyslip.2011.09.002Bodner, E., Afri, M., & Frimer, A. A. (2010). Determining radical penetration into membranes using ESR splitting constants. Free Radical Biology and Medicine, 49(3), 427-436. doi:10.1016/j.freeradbiomed.2010.04.029Laguerre, M., López Giraldo, L. J., Lecomte, J., Figueroa-Espinoza, M.-C., Baréa, B., Weiss, J., … Villeneuve, P. (2009). Chain Length Affects Antioxidant Properties of Chlorogenate Esters in Emulsion: The Cutoff Theory Behind the Polar Paradox. Journal of Agricultural and Food Chemistry, 57(23), 11335-11342. doi:10.1021/jf9026266Laguerre, M., López Giraldo, L. J., Lecomte, J., Figueroa-Espinoza, M.-C., Baréa, B., Weiss, J., … Villeneuve, P. (2010). Relationship between Hydrophobicity and Antioxidant Ability of «Phenolipids» in Emulsion: A Parabolic Effect of the Chain Length of Rosmarinate Esters. Journal of Agricultural and Food Chemistry, 58(5), 2869-2876. doi:10.1021/jf904119vAliaga, C., Bravo-Moraga, F., Gonzalez-Nilo, D., Márquez, S., Lühr, S., Mena, G., & Rezende, M. C. (2016). Location of TEMPO derivatives in micelles: subtle effect of the probe orientation. Food Chemistry, 192, 395-401. doi:10.1016/j.foodchem.2015.07.036Aliaga, C., López de Arbina, A., & Rezende, M. C. (2016). «Cut-off» effect of antioxidants and/or probes of variable lipophilicity in microheterogeneous media. Food Chemistry, 206, 119-123. doi:10.1016/j.foodchem.2016.03.024Lopez de Arbina, A., Rezende, M. C., & Aliaga, C. (2017). Cut-off effect of radical TEMPO derivatives in olive oil-in-water emulsions. Food Chemistry, 224, 342-346. doi:10.1016/j.foodchem.2016.12.058Agostinis, P., Berg, K., Cengel, K. A., Foster, T. H., Girotti, A. W., Gollnick, S. O., … Golab, J. (2011). Photodynamic therapy of cancer: An update. CA: A Cancer Journal for Clinicians, 61(4), 250-281. doi:10.3322/caac.20114Kamkaew, A., Lim, S. H., Lee, H. B., Kiew, L. V., Chung, L. Y., & Burgess, K. (2013). BODIPY dyes in photodynamic therapy. Chem. Soc. Rev., 42(1), 77-88. doi:10.1039/c2cs35216hYano, S., Hirohara, S., Obata, M., Hagiya, Y., Ogura, S., Ikeda, A., … Joh, T. (2011). Current states and future views in photodynamic therapy. Journal of Photochemistry and Photobiology C: Photochemistry Reviews, 12(1), 46-67. doi:10.1016/j.jphotochemrev.2011.06.001Dolmans, D. E. J. G. J., Fukumura, D., & Jain, R. K. (2003). Photodynamic therapy for cancer. Nature Reviews Cancer, 3(5), 380-387. doi:10.1038/nrc1071Bronshtein, I., Afri, M., Weitman, H., Frimer, A. A., Smith, K. M., & Ehrenberg, B. (2004). Porphyrin Depth in Lipid Bilayers as Determined by Iodide and Parallax Fluorescence Quenching Methods and Its Effect on Photosensitizing Efficiency. Biophysical Journal, 87(2), 1155-1164. doi:10.1529/biophysj.104.041434Lavi, A., Weitman, H., Holmes, R. T., Smith, K. M., & Ehrenberg, B. (2002). The Depth of Porphyrin in a Membrane and the Membrane’s Physical Properties Affect the Photosensitizing Efficiency. Biophysical Journal, 82(4), 2101-2110. doi:10.1016/s0006-3495(02)75557-4Chattopadhyay, A., & London, E. (1987). Parallax method for direct measurement of membrane penetration depth utilizing fluorescence quenching by spin-labeled phospholipids. Biochemistry, 26(1), 39-45. doi:10.1021/bi00375a006Nuin, E., Gómez-Mendoza, M., Andreu, I., Marin, M. L., & Miranda, M. A. (2012). New Photoactive Compounds To Probe Cholic Acid and Cholesterol inside Mixed Micelles. Organic Letters, 15(2), 298-301. doi:10.1021/ol303201yNuin, E., Gomez-Mendoza, M., Marin, M. L., Andreu, I., & Miranda, M. A. (2013). Influence of Drug Encapsulation within Mixed Micelles on the Excited State Dynamics and Accessibility to Ionic Quenchers. The Journal of Physical Chemistry B, 117(32), 9327-9332. doi:10.1021/jp404353uGomez-Mendoza, M., Nuin, E., Andreu, I., Marin, M. L., & Miranda, M. A. (2012). Photophysical Probes To Assess the Potential of Cholic Acid Aggregates as Drug Carriers. The Journal of Physical Chemistry B, 116(34), 10213-10218. doi:10.1021/jp304708yBoschloo, G., & Hagfeldt, A. (2009). Characteristics of the Iodide/Triiodide Redox Mediator in Dye-Sensitized Solar Cells. Accounts of Chemical Research, 42(11), 1819-1826. doi:10.1021/ar900138mGardner, J. M., Abrahamsson, M., Farnum, B. H., & Meyer, G. J. (2009). Visible Light Generation of Iodine Atoms and I−I Bonds: Sensitized I−Oxidation and I3−Photodissociation. Journal of the American Chemical Society, 131(44), 16206-16214. doi:10.1021/ja905021cSangster, J. (1989). Octanol‐Water Partition Coefficients of Simple Organic Compounds. Journal of Physical and Chemical Reference Data, 18(3), 1111-1229. doi:10.1063/1.55583

Programa de adquisición de habilidades y capacidades para el desempeño profesional a través del Prácticum en Psicología Social. (continuación)

Con este proyecto tratamos de dar continuidad a una iniciativa que pusimos en marcha el hace ya dos años, con el objetivo de facilitar la transición entre el mundo académico y la realidad profesional con la que los estudiantes empiezan a tomar contacto a través del prácticum. Se trata de ofreceros orientación, asesoramiento y formación complementaria a la que formalmente se recibe en el Grado, clarificar el rol profesional y lo que puede esperar el estudiante del mundo profesional. Para ello contamos con tres pilares fundamentales: A) Ponencias de profesionales de la Psicología Social. B) Formación en competencias profesionales: impartidas por vari@s profesor@s del departamento de Psicología Social. C) Visitas a los centros: la universidad se acerca al mundo profesional

Exploring the Different Degrees of Magnetic Disorder in TbxR1−xCu2 Nanoparticle Alloys

Recently, potential technological interest has been revealed for the production of magnetocaloric alloys using Rare-Earth intermetallics. In this work, three series of TbxR1−xCu2 (R ≡ Gd, La, Y) alloys have been produced in bulk and nanoparticle sizes via arc melting and high energy ball milling. Rietveld refinements of the X-ray and Neutron diffraction patterns indicate that the crystalline structure in all alloys is consistent with TbCu2 orthorhombic Imma bulk crystalline structure. The analyses of the DC-magnetisation (MDC) and AC-susceptibility (χAC) show that three distinct degrees of disorder have been achieved by the combination of both the Tb3+ replacement (dilution) and the nanoscaling. These disordered states are characterised by transitions which are evident to MDC, χAC and specific heat. There exists an evolution from the most ordered Superantiferromagnetic arrangement of the Tb0.5La0.5Cu2 NPs with Néel temperature, TN∼ 27 K, and freezing temperature, Tf∼ 7 K, to the less ordered weakly interacting Superparamagnetism of the Tb0.1Y0.9Cu2 nanoparticles (TN absent, and TB∼ 3 K). The Super Spin Glass Tb0.5Gd0.5Cu2 nanoparticles (TN absent, and Tf∼ 20 K) are considered an intermediate disposition in between those two extremes, according to their enhanced random-bond contribution to frustration.This work has been supported by the Spanish MAT2017-83631-C3-R grant. E.M.J.’s work was supported by “Beca de Colaboración”, BDNS: 311327 granted by Ministerio de Educación, Cultura y Deporte and “Beca Concepción Arenal” BDNS: 406333 granted by the Gobierno de Cantabria and the Universidad de Cantabria. MRF work was supported by FPI (BES-2012-058722)

Investigating the Size and Microstrain Influence in the Magnetic Order/Disorder State of GdCu2 Nanoparticles

A series of GdCu 22 nanoparticles with controlled sizes ranging from 7 nm to 40 nm has been produced via high-energy inert-gas ball milling. Rietveld refinements on the X-ray diffraction measurements ensure that the bulk crystalline ImmaImma structure is retained within the nanoparticles, thanks to the employed low milling times ranging from t = 0.5 to t = 5 h. The analysis of the magnetic measurements shows a crossover from Superantiferromagnetism (SAF) to a Super Spin Glass state as the size decreases at NP size of ?D???D?? 18 nm. The microstrain contribution, which is always kept below 1%, together with the increasing surface-to-core ratio of the magnetic moments, trigger the magnetic disorder. Additionally, an extra contribution to the magnetic disorder is revealed within the SAF state, as the oscillating RKKY indirect exchange achieves to couple with the aforementioned contribution that emerges from the size reduction. The combination of both sources of disorder leads to a maximised frustration for ?D???D?? 25 nm sized NPs.This work has been supported by MAT2017-83631-C3-R. EMJ thanks the “Beca Concepción Arenal” BDNS: 406333 granted by the Gobierno de Cantabria and the Universidad de Cantabri

Developmental regulation of apical endocytosis controls epithelial patterning in vertebrate tubular organs

© 2015 Macmillan Publishers Limited. Epithelial organs develop through tightly coordinated events of cell proliferation and differentiation in which endocytosis plays a major role. Despite recent advances, how endocytosis regulates the development of vertebrate organs is still unknown. Here we describe a mechanism that facilitates the apical availability of endosomal SNARE receptors for epithelial morphogenesis through the developmental upregulation of plasmolipin (pllp) in a highly endocytic segment of the zebrafish posterior midgut. The protein PLLP (Pllp in fish) recruits the clathrin adaptor EpsinR to sort the SNARE machinery of the endolysosomal pathway into the subapical compartment, which is a switch for polarized endocytosis. Furthermore, PLLP expression induces apical Crumbs internalization and the activation of the Notch signalling pathway, both crucial steps in the acquisition of cell polarity and differentiation of epithelial cells. We thus postulate that differential apical endosomal SNARE sorting is a mechanism that regulates epithelial patterning.MINECO (BFU2011-22622) and CONSOLIDER (CSD2009-00016); Fundación Obra Social `La Caixa' PhD fellowship. G.A. was supported by the Amarouto Program for senior researchers from the Comunidad Autónoma de Madrid.Peer Reviewe

Magnetocaloric properties of rapidly solidified Dy3Co alloy ribbons

"The magnetic and magnetocaloric (MC) properties of melt-spun ribbons of the Dy3Co intermetallic compound were investigated. Samples were fabricated in an Ar environment using a homemade melt spinner system at a linear speed of the rotating copper wheel of 40 ms(-1). X-ray diffraction analysis shows that ribbons crystallize into a single-phase with the Fe3C-type orthorhombic crystal structure. The M(T) curve measured at 5mT reveals the occurrence of a transition at 32K from a first to a second antiferromagnetic (AFM) state and an AFM-to-paramagnetic transition at T-N = 43 K. Furthermore, a metamagnetic transition is observed below T-N, but the magnetization change Delta M is well below the one reported for bulk alloys. Below 12 K, large inverse MC effect and hysteresis losses are observed. This behavior is related to the metamagnetic transition. For a magnetic field change of 5 T (2 T) applied along the ribbon length, the produced ribbons show a peak value of the magnetic entropy change Delta S-M(peak) of -6.5 (-2.1) Jkg(-1) K-1 occurring close to TN with a full-width at half-maximum delta T-FWHM of 53 (37) K, and refrigerant capacity RC = 364 (83) Jkg(-1) (estimated from the product vertical bar Delta S-M(peak)vertical bar x delta T-FWHM).

A global perspective on carotenoids: metabolism, biotechnology, and benefits for nutrition and health.

Carotenoids are lipophilic isoprenoid compounds synthesized by all photosynthetic organisms and some non-photosynthetic bacteria and fungi. With some notable exceptions, animals (including humans) do not produce carotenoids de novo but take them in their diets. In photosynthetic systems carotenoids are essential for photoprotection against excess light and contribute to light harvesting, but perhaps they are best known for their properties as natural pigments in the yellow to red range. Carotenoids can be associated to fatty acids, sugars, proteins, or other compounds that can change their physical and chemical properties and influence their biological roles. Furthermore, oxidative cleavage of carotenoids produces smaller molecules such as apocarotenoids, some of which are important pigments and volatile (aroma) compounds. Enzymatic breakage of carotenoids can also produce biologically active molecules in both plants (hormones, retrograde signals) and animals (retinoids). Both carotenoids and their enzymatic cleavage products are associated with other processes positively impacting human health. Carotenoids are widely used in the industry as food ingredients, feed additives, and supplements. This review, contributed by scientists of complementary disciplines related to carotenoid research, covers recent advances and provides a perspective on future directions on the subjects of carotenoid metabolism, biotechnology, and nutritional and health benefits

Magnetic study of co-doped magnetosome chains

Magnetotactic bacteria synthesize a chain of magnetic nanoparticles, called magnetosome chain, used to align and swim along the geomagnetic field lines. In particular, Magnetospirillum gryphiswaldense biomineralize magnetite, Fe3O4. Growing this species in a Co-supplemented medium, Co-doped magnetite is obtained, tailoring in this way the magnetic properties of the magnetosome chain. Combining structural and magnetic techniques such as transmission electron microscopy, energy-dispersive x-ray spectroscopy, X-ray absorption near edge structure, and X-ray magnetic circular dichroism, we determine that 1% of Co2+ substitutes Fe2+ located in octahedral places in the magnetite, thus increasing the coercive field. In the framework of the Stoner-Wohlfarth model, we have analyzed the evolution of the hysteresis loops as a function of temperature determining the different magnetic anisotropy contributions and their evolution with temperature. In contrast with the control magnetosome chains, whose effective anisotropy is uniaxial in the whole temperature range from 300 to 5 K, the effective anisotropy of Codoped magnetosome chains changes appreciably with temperature, from uniaxial down to 150 K, through biaxial down to 100 K, to triaxial below 100 K.L.M. acknowledges the Basque Government for her fellowship (PRE_2015_1_0130). We acknowledge the technical and human support provided by SGIker (UPV/EHU). Funding from the Spanish Government (project nos. MAT2014-55049-C2-R and MAT2017-83631-C3-R) and Basque Government (project n. IT711-13) is acknowledged. We thank the ESRF (CRG BM25 beamline-SpLine) and HZB for the allocation of synchrotron radiation beamtime and funding under the project CALIPSOplus (Grant Agreement 730872) from the EU Framework Programme for Research and Innovation HORIZON 2020. We thank R. Fernández-Pacheco for his assistance in the EDS measurements