La importancia del capital humano como impulsor de la innovación

This article seeks to clarify the impact of human capital on the innovation capacity of companies. We employ the literature review and some personals interpretations. Results have relevant implications for managers of companies that are interested in promoting thier innovation activity. By considering how human capital is related with the innovation process, this article attempts to provide a useful guide of human capital indicators within the intellectual capital framework. We consider that the basic contribution of our work is the development of a system of indicators for human capital management with the objective of allowing for a clear picture of links between strategic human resources and the innovation capacity of companies. Moreover, it can be easily adapted to a given type of organization and, therefore, serve to compare companies belonging to the same sector of activityEl objetivo de este artículo es definir el impacto del capital humano en la capacidad innovadora de las empresas y para ello hemos recurrido a la revisión de la literatura y a nuestras interpretaciones personales. Los resultados demuestran implicaciones de peso para los directores de empresas que se muestran interesados en promocionar la actividad innovadora. Mediante esta consideración de la forma en la que el capital humano influye en el proceso de la innovación, este artículo pretende servir de guía útil sobre los indicadores del capital humano dentro del marco del capital intelectual. Consideramos que la aportación fundamental de nuestro trabajo consiste en el desarrollo de un sistema de indicadores para la gestión del capital humano con el objetivo de ilustrar claramente una serie de vínculos entre los recursos humanos estratégicos y la capacidad innovadora de las empresas. Además, puede adaptarse fácilmente a un tipo determinado de organización y, por tanto, servir para comparar empresas que pertenezcan al mismo sector de activida

A Role for DPPX Modulating External TEA Sensitivity of Kv4 Channels

Shal-type (Kv4) channels are expressed in a large variety of tissues, where they contribute to transient voltage-dependent K+ currents. Kv4 are the molecular correlate of the A-type current of neurons (ISA), the fast component of ITO current in the heart, and also of the oxygen-sensitive K+ current (KO2) in rabbit carotid body (CB) chemoreceptor cells. The enormous degree of variability in the physiological properties of Kv4-mediated currents can be attributable to the complexity of their regulation together with the large number of ancillary subunits and scaffolding proteins that associate with Kv4 proteins to modify their trafficking and their kinetic properties. Among those, KChIPs and DPPX proteins have been demonstrated to be integral components of ISA and ITO currents, as their coexpression with Kv4 subunits recapitulates the kinetics of native currents. Here, we explore the presence and functional contribution of DPPX to KO2 currents in rabbit CB chemoreceptor cells by using DPPX functional knockdown with siRNA. Additionally, we investigate if the presence of DPPX endows Kv4 channels with new pharmacological properties, as we have observed anomalous tetraethylammonium (TEA) sensitivity in the native KO2 currents. DPPX association with Kv4 channels induced an increased TEA sensitivity both in heterologous expression systems and in CB chemoreceptor cells. Moreover, TEA application to Kv4-DPPX heteromultimers leads to marked kinetic effects that could be explained by an augmented closed-state inactivation. Our data suggest that DPPX proteins are integral components of KO2 currents, and that their association with Kv4 subunits modulate the pharmacological profile of the heteromultimers

Developing Number Sense: An Approach to Initiate Algebraic Thinking in Primary Education

Traditionally, the teaching and learning of algebra has been addressed at the beginning of secondary education with a methodological approach that broke traumatically into a mathematical universe until now represented by numbers, with bad consequences. It is important, then, to find methodological alternatives that allow the parallel development of arithmetical and algebraic thinking from the first years of learning. This article begins with a review of a series of theoretical foundations that support a methodological proposal based on the use of specific manipulative materials that foster a deep knowledge of the decimal number system, while verbalizing and representing quantitative situations that underline numerical relationships and properties and patterns of numbers. Developing and illustrating this approach is the main purpose of this paper. The proposal has been implemented in a group of 25 pupils in the first year of primary school. Some observed milestones are presented and analyzed. In the light of the results, this well-planned early intervention contains key elements to initiate algebraic thinking through the development of number sense, naturally enhancing the translation of purely arithmetical situations into the symbolic language characteristic of algebraic thinking.University of Cordoba 2020-4-400

Effect of lamellar orientation and width on the strength and operating deformation mechanisms of fully lamellar TiAl alloys determined by micropillar compression

Titanium aluminide alloys are of interest for the aerospace industry due to their low density(3.9-4.2g/cm3), good high-temperature strength retention, high modulus and creep strength, as well as high resistance to oxidation. The TiAl alloys of commercial interest typically contain two phases: γ TiAl and a2 Ti3Al, but their microstructure can substantially vary depending on composition and thermomechanical history. They can be classified as fully lamellar, near lamellar, duplex or near gamma. Fully lamellar microstructures formed by colonies of lamellar γ and a2 phases are typically obtained after heat treatment at temperatures above the a-transus, with the soaking temperature and cooling rate [1] being critical variables to determine the microstructural parameters, such as colony size, volume fraction and lamellar width. They present the best high temperature strength [1-2]; However, they lack room temperature ductility, which has limited their application so far. In this context, several compositional families have been developed in the last years, especially as a function of alloying elements, such as, niobium, tantalum, tungsten or molybdenum, which stabilize the β phase affecting the volume fraction and size of lamellar colonies. Two of the most important families are TNB alloys, with high niobium concentration and small additions of boron and carbon, where solidification takes place through the phase and TNM alloys, with even larger additions of niobium and molybdenum. Solidification of TNM alloys takes place through the β phase inducing further grain refinement due to β→a transformation [3] during cooling. The lack of ductility of fully lamellar TiAl alloys is associated with the anisotropic deformation of individual colonies, as a function of lamellar orientation () with respect to the loading axis. In this regard, micropillar compression is a powerful technique to determine the different deformation modes of TiAl colonies as a function of lamellar orientation. This has been shown in previous studies for TNB alloys (Ti45Al2Nb2MnXB), where the outcomes of micropillar compression were compared with results obtained from macroscopic tests using polysynthetically twinned crystals (PTS) [4]. Three different deformation modes where found: a soft deformation mode (=45º) and two hard modes (=0º and =90º), due to the activation of different slip systems in each case. However, the role of lamellar width has not been studied in detail before. This work focuses on an alloy belonging to the TNM family, with the objective of studying the role of lamellar orientation and lamellar width on the anisotropic mechanical response of individual colonies. For this, a Ti43.5Al4Nb1MoXB alloy was subjected to different thermal treatments with the objective of refining the lamellar width. In particular, after heating up and soaking at 1260ºC (above the a-transus), three cooling rates were selected to cool down to 800ºC (a2 + β + γ region): 40ºC/min, 400ºC/min and 4000ºC/min. The cooling rate was reduced to 40ºC/min from 800ºC in all cases to avoid cracking. As a result, the average lamellar width was varied within a range of two orders of magnitude (from a few nanometers to more than 200nm) for the same alloy composition. The anisotropy of individual colonies and their deformation modes as a function of lamellar orientation were studied by micropillar compression. For this, square micropillars were milled by means of FIB with dimensions of 5 x 5 x 15m3. Uniaxial compression was carried out using a flat-punch diamond tip with a diameter of 10m under displacement control mode at a strain rate of 10-3 s-1 up to a maximum engineering strain of 10%. Deformed micropillars were analyzed to relate the orientation of lamellar interfaces with the activation of different deformation modes. The results are compared with those obtained in TNB alloys as well as a function of the average lamellar width. [1] F. Appel, J. Paul, M. Oehring, Gamma Titanium Aluminide Alloys: Science and Technology. Wiley, 2011. [2] M.E. Kassner, M.T. Pérez-Prado. Fundamentals of Creep in Metals and Alloys, Elsevier, 2004. [3] H. Clemens, S. Mayer, Adv. Eng. Mater. 15 (2013) 191–215. [4] A.J. Palomares-García, M.T. Pérez Prado, J.M. Molina-Aldareguia Acta Mater. 123 (2017) 102-114

Insulators containing CuCl4X22? (X = H2O, NH3) units: Origin of the orthorhombic distortion observed only for CuCl4(H2O)2 2?

The origin of the difference in structure between compounds containing CuCl4X22? (X=H2O, NH3) units is analyzed by means of first-principles calculations. While NH3-containing compounds display tetragonal symmetry, H2O-containing ones display an orthorhombic distortion at low temperature where the equatorial Cl? ions are no longer equivalent. Our simulations of optical and vibrational transitions show good agreement with all available experimental optical absorption and Raman data. As a salient feature, the value of the force constant for the B1g mode, K(B1g), driving the orthorhombic distortion in the CuCl4(H2O)22? unit is found to be four times smaller than that calculated for CuCl4(NH3)22?, stressing that CuCl4(H2O)22? is in the verge of the D4h?D2h instability. The analysis of results obtained for different values of the distortion coordinate, Q(B1g), clearly shows that the softening undergone by K(B1g) in CuCl4(H2O)22? comes mainly from the vibronic admixture of the antibonding a?1g(?3z2-r2) orbital with the bb1g bonding (or charge transfer) level. This mechanism is thus similar to that responsible for distortions observed in some fluoroperovskites and oxoperovskites. The present results, quantifying the importance of vibronic effects in structural instabilities, clearly demonstrate that, contrary to what was suggested by several authors, the instability in CuCl4(H2O)22? is not related to the Jahn-Teller effect and that the orthorhombic distortion observed in the pure compound Rb2CuCl4(H2O)2 has a local origin.The support by the Spanish Ministerio de Ciencia y Tecnología under Project No. FIS2009-07083 is acknowledged

Espondilitis tuberculosa no es una metástasis vertebral: diagnóstico diferencial y tratamiento quirúrgico. A propósito de un caso

Presentamos el caso de una paciente con dorsalgia y clínica neurológica de varios meses de evolución que ante las pruebas de imagen fue erróneamente diagnosticada de metástasis vertebral sin confirmación previa con biopsia. El deterioro progresivo neurológico y las nuevas pruebas de imagen confirmaron el diagnóstico de tuberculosis vertebral. La paciente fue tratada mediante curetaje, desbridamiento, fusión intersomática y osteosíntesis anterior además del tratamiento médico. Hubo una recuperación neurológica de la función sensitiva, motora y esfinteriana prácticamente completa al mes de la intervención. Tras 20 meses de evolución la paciente está asintomática sin evidencia de progresión de la enfermedadWe report a patient with back pain and neurological symptoms several months of evolution to the test image was wrongly diagnosed with spinal metastases without prior confirmation with biopsy. The progressive deterioration of neurological and new imaging confirmed the diagnosis of spinal tuberculosis. The patient was treated by curettage, debridement, anterior interbody fusion and internal fixation in addition to medical treatment. There neurological recovery of sensory function, motor and sphincter almost complete month after the intervention. After 20 months of evolution, the patient is asymptomatic without evidence of disease progressio

Internal electric fields and color shift in Cr3+-based gemstones

Seeking to better understand the origin of the different colors of emerald and ruby, both ab initio periodic and cluster calculations have been carried out. The calculations reproduce the interatomic distances measured for pure Be3Si6Al2O18 and Al2O3 as well as the Cr3+?O2? distances in emerald and ruby. The mean Cr3+?O2? distance for Be3Si6Al2O18:Cr3+ and Al2O3:Cr3+ is found to be practically equal to 1.97 Å, in agreement with recent experimental values. The present calculations confirm that the variations of optical properties due to Cr3+ impurities along the series of ionic oxides can be understood merely through the CrO69? unit but subject to the electric field due to the rest of the lattice ions. As a salient feature it is proved that changes in electronic density and covalency due to the internal field are not the cause of the color shift. Therefore, the red color of ruby is not due to the polarization of the electronic cloud around chromium as a result of the C3 local symmetry. The present study also demonstrates that the variation of the ligand field splitting parameter, 10Dq, induced by the internal electric field comes mainly from the contributions of first shells of ions around the CrO69? unit. As a consequence, 10Dq in emerald is not influenced by the internal field, as the contribution from Be2+ first neighbors is practically compensated by that of Si4+ second neighbors. In contrast, in ruby the t2g levels are shifted by the internal field 0.24 eV more than the eg ones, so explaining the color shift in this gemstone in comparison with emerald. This result is shown to arise partially from the asymmetric form of the internal electrostatic potential along the C3 axis in Al2O3.Support from the Spanish Ministerio de Ciencia y Tecnología under Project No. FIS2009-07083 is acknowledge

Application of a robust QFT linear control method to the course changing manoeuvring of a ship

This paper describes in detail the design methodology of a robust QFT (Quantitative Feedback Theory) controller for the control of the course changing of a ship. A linear model is used with uncertainty in the parameters. The system is designed to fulfil the specifications of robust stability and robust tracking of a reference system

Connecting the chemical and biological reactivity of epoxides

The chemical reactivity of the mutagenic epoxides (EP) propylene oxide (PO), 1,2-epoxybutane (1,2-EB), and cis- and trans-2,3-epoxybutane (cis- and trans-2,3-EB) with 4-(p-nitrobenzyl)pyridine (NBP), a bionucleophile model for S(N)2 alkylating agents with high affinity for the guanine-N7 position, was investigated kinetically. It was found that three reactions are involved simultaneously: the alkylation reaction of NBP by EP, which yields the corresponding NBP-EP adducts through an S(N)2 mechanism, and EP and NBP-EP hydrolysis reactions. PO and 1,2-EB were seen to exhibit a higher alkylating potential than cis- and trans-2,3-EB. From a study of the correlations between the chemical reactivity (kinetic parameters) and the biological effectiveness of oxiranes, the following conclusions can be drawn: (i) the hydrolysis reactions of epoxides must be taken into account to understand their bioactivity. (ii) The fraction (f) of the alkylating oxirane that forms the adduct and the adduct life (AL) permit the potential of epoxides as bioactive molecules to be rationalized even semiquantitatively; and (iii) alkylation of DNA by epoxides and the O-6-/N7-guanine adduct ratio are directly related to their mutagenicity in vitro.Publicad

Fat-specific FUS-DDIT3-transgenic mice establish PPARgamma inactivation is required to liposarcoma development.

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