Formation and dissolution of inter-firm linkages in lengthy and stable networks in clusters

[EN] Firms aspire to take advantage of technical and business networks through inter-organizational interactions to improve performance. Consequently, researchers are increasingly focusing on the dynamics and implications of network formation at both local and global levels. The recent research trend does not consider a monotonic effect and simplistic approach to proximity because proximity is a complex multidimensional concept. Using data from a foodstuffs cluster in the Valencian region (Spain) and advanced econometric methods such as Exponential Random Graph Models, this study aims to clarify the detrimental effects and complementarities that may arise among proximity dimensions. After controlling for network endogenous forces and firm characteristics, findings reveal the negative effect of cognitive and institutional proximity dimensions on the creation of linkages in advanced stages of the cluster life cycle. Furthermore, social proximity and geographical proximity favor the formation of inter-firm relationships and reinforce the organizational dimension.The authors acknowledge the financial support of the Spanish Ministry of Economy and Competitiveness (Research Project Number ECO2012-32663 and Research Project Number ECO2010-2055).Molina Morales, FX.; Belso Martínez, JA.; Mas Verdú, F.; Martínez Cháfer, L. (2015). Formation and dissolution of inter-firm linkages in lengthy and stable networks in clusters. Journal of Business Research. 68(7):1557-1562. https://doi.org/10.1016/j.jbusres.2015.01.051S1557156268

Influência da atividade física em crianças com TDAH e possibilidade de tratamento na área de Educação Física

Resumen: Los alumnos con Necesidades Educativas Especiales, suelen quedar excluidos de las clases de Educación Física y por esta razón las investigaciones del ámbito educativo pretenden demostrar el potencial que puede tener la actividad física, en cualquier discente, independientemente de sus capacidades. El objetivo de este trabajo es evaluar la relación entre la actividad física y el Trastorno por Déficit de Atención con Hiperactividad (TDAH), centrando la atención en la forma de trabajarlo desde el área de la Educación Física. En el siguiente texto se pretende definir este tipo de trastorno, así como sus principales síntomas. Se estudia la influencia positiva de la actividad física y el tratamiento necesario para el proceso de enseñanza y aprendizaje en niños con TDAH. Por último, se indagará acerca del impacto positivo en el comportamiento y en la función neurocognitiva de dichos niños a través de la actividad física, subrayando la idea de que el área de Educación Física puede colaborar en la intervención psicoeducativa y conseguir así mejoras conductuales como alternativas al tratamiento farmacológico.Abstract: Students with Special Educational Needs are often excluded from physical education classes and for this reason educational research aims to demonstrate the potential that physical activity can have, in any discent, regardless of their abilities. The goal of this work is to evaluate the relationship between physical activity and Attention Deficit Hyperactivity Disorder (ADHD), focusing attention on how you work it from the area of Physical Education. The following text is intended to define this type of disorder, as well as its main symptoms. The positive influence of physical activity and treatment needed for the teaching and learning process in children with ADHD is studied. Finally, it will be inquired about the positive impact on the behavior and neurocognitive function of these children through physical activity, underlining the idea that the area of Physical Education can collaborate in psychoeducational intervention and thus achieve behavioral improvements as alternatives to pharmacological treatment.Resumo: Alunos com Necessidades Educacionais Especiais são frequentemente excluídos das aulas de educação física e, por isso, a pesquisa educacional tem como objetivo demonstrar o potencial que a atividade física pode ter, em qualquer desdocente, independentemente de suas habilidades. O objetivo deste trabalho é avaliar a relação entre atividade física e Transtorno do Déficit de Atenção com Hiperatividade (TDAH), focando a atenção em como você trabalha na área de Educação Física. O texto a seguir destina-se a definir esse tipo de transtorno, bem como seus principais sintomas. Estuda-se a influência positiva da atividade física e do tratamento necessários para o processo de ensino e aprendizagem em crianças com TDAH. Por fim, será indagado sobre o impacto positivo no comportamento e na função neurocognitiva dessas crianças por meio da atividade física, destacando a ideia de que a área de Educação Física pode colaborar na intervenção psicoeducativa e, assim, alcançar melhorias comportamentais como alternativas ao tratamento farmacológico

Humoral response (IgG) of goats experimentally infected with Fasciola hepatica against cysteine proteinases of adult fluke

The use of cysteine proteinases from Fasciola hepatica adult flukes for the serodiagnosis of caprine fasciolosis by means of an indirect ELISA test was studied. Two proteolytic fractions from adult fluke homogenates, with apparent molecular weights of 28 and 34 kDa (P28 and P34 respectively), were characterised as cysteine proteinases using azocasein assays and gelatin gel analysis. Both P28 and P34 fractions were electroluted and used as antigens in two different indirect ELISA tests. Serum IgG levels against P28 and P34 in goats given an experimental primary infection with 200 metacercariae or in goats given two experimental infections with 200 metacercariae were determined and compared with those observed in an uninfected control group. ELISA tests using both cysteine proteases showed a rapid and consistent detection of specific IgG in all experimentally infected goats. The IgG response to P28 was the first to be detected as early as 2–3 weeks post-infection and remained elevated throughout the experiment. The response to P34 was detected later (4–6 wpi) and disappeared in some animals at 18 wpi, while flukes were still present in the bile ducts. No significant differences were observed between the anti-P28 and anti-P34 IgG responses between animals receiving a primary or a challenge infection. The results of our study, although preliminary, are promising since the P28 ELISA described here may be a reliable method for the immunodiagnosis of F. hepatica infection in goats

Una aplicación de la Teoría de la Información al análisis de datos definidos mediante variables cualitativas multiestado: medidas de similaridad y análisis Cluster

Sin resume

Photodegradation of cytostatic drugs by g-C3N4: Synthesis, properties and performance fitted by selecting the appropriate precursor

Graphitic carbon nitride (g-C3N4) was synthetized by a one-step thermal method from different N-rich precursors, namely melamine, dicyandiamide, urea, thiourea and cyanamide. The structure, optical and physicochemical properties of g-C3N4 materials were studied by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy, among others. Both melamine and dicyandiamide provided a less porous structure composed by large flake sheets, whereas urea and thiourea favoured g-C3N4 composed by small flat sheets and wrinkles with a larger porosity. The establishment of more condensed g-C3N4 networks with a reduced band gap was also evidenced for melamine and dicyandiamide precursors, while urea favoured less condensed melem or melon structures. The photoactivity of the different g-C3N4 was assessed for the removal of an aqueous solution containing 5-fluorouracil (5-FU), cyclophosphamide (CP) or a mixture of both cytostatic drugs, under near UV-Vis and solar-LED irradiations. The best performing photocatalysts under near UV-Vis irradiation, were those prepared from melamine (kapp = 14.6 × 10–2 min–1 for 5-FU) and thiourea (kapp = 2.5 × 10–2 min–1 for CP), while urea was the most active under solar-LED irradiation (kapp = 0.183 × 10–2 min–1 for 5-FU). In addition, CP was more resistant to be degraded than 5-FU, and a competitive effect for the generated hydroxyl radicals was evidenced when both pollutant molecules were in the same solution. The photoactivity of g-C3N4 materials was justified by the combination of various effects: (i) surface area, (ii) well-connected and condensed g-C3N4 structures and (iii) high surface C/N ratios with nitrogen vacanciesSpanish Projects from MCIN/AEI/FEDER "Una manera de hacer Europa" RTI2018-099224-B-I00FEDER/Junta de Andalucia-Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades B-RNM-486-UGR20Junta de Andalucia-Consejeria de Universidad, Investigacion e Innovacion -Proyecto P21_00208MICIN/AEIEuropean Social Found (FSE) PRE2019-087946MICIN/AEI RYC-2019-026634-IFSE "El FSE invierte en tu futuro"Universidad de Granada/CBU

Functionalized Graphene Derivatives and TiO2 for High Visible Light Photodegradation of Azo Dyes

Functionalized graphene derivatives including graphene oxide (GO), reduced graphene oxide (rGO), and heteroatom (nitrogen/sulphur (N/S) or boron (B))-doped graphene were used to synthesize composites with TiO2 (T). The photocatalytic performance of composites was assessed for the degradation of Orange G dye (OG) under simulated solar light. All the prepared graphene derivatives—TiO2 composites showed better photocatalytic performance than bare TiO2. A higher photocatalytic activity was found for the composites containing GO and N/S co-doped rGO (kapp = 109.2 × 10−3 and 48.4 × 10−3 min−1 , for GO-T and rGONS-T, respectively). The influence of both initial solution pH and the reactive species involved in the OG degradation pathway were studied. The photocatalytic activity of the samples decreased with the increase of the initial pH (from 3.0 to 10.0) due to the occurrence of electrostatic repulsive forces between the photocatalysts surface and the molecules of OG, both negatively charged. The use of selective scavengers showed that although the photogenerated holes dominate the degradation mechanism, radicals and singlet oxygen also participate in the OG degradation pathway. In addition, reutilization experiments indicated that the samples were stable under the reaction conditions used.ERDF/Ministry of Science, Innovation and Universities-State Research Agency RTI2018-099224-B-I0

Extracellular calcium promotes bone formation from bone marrow mesenchymal stem cells by amplifying the effects of BMP-2 on SMAD signalling

Understanding the molecular events that regulate osteoblast differentiation is essential for the development of effective approaches to bone regeneration. In this study, we analysed the osteoinductive properties of extracellular calcium in bone marrow-derived mesenchymal stem cell (BM-MSC) differentiation. We cultured BM-MSCs in 3D gelatin scaffolds with Ca2+ and BMP-2 as osteoinductive agents. Early and late osteogenic gene expression and bone regeneration in a calvarial critical-size defect model demonstrate that extracellular Ca2+ enhances the effects of BMP-2 on Osteocalcin, Runx2 and Osterix expression and promotes bone regeneration in vivo. Moreover, we analysed the molecular mechanisms involved and observed an antagonistic effect between Ca2+ and BMP-2 on SMAD1/5, ERK and S6K signalling after 24 hours. More importantly, a cooperative effect between Ca2+ and BMP-2 on the phosphorylation of SMAD1/5, S6, GSK3 and total levels of β-CATENIN was observed at a later differentiation time (10 days). Furthermore, Ca2+ alone favoured the phosphorylation of SMAD1, which correlates with the induction of Bmp2 and Bmp4 gene expression. These data suggest that Ca2+ and BMP-2 cooperate and promote an autocrine/paracrine osteogenic feed-forward loop. On the whole, these results demonstrate the usefulness of calcium-based bone grafts or the addition of exogenous Ca2+ in bone tissue engineering

El estudiante como capital humano en la educación secundaria : un análisis del impacto de variables sociodemográficas en la percepción del aprendizaje

Spain (statistically and at European level) occupies the top positions among the countries with the highest school dropout rates; and along the same lines, various studies (INE, 2020; Vaquero, 2011) confirm that teachers in our country consider that education must be transformed to ensure that all students feel that they are the protagonists of the learning process; and that - in addition - everything they learn can be transferred to develop as citizens to the extent that their needs are also met (Álvarez et al., 2020:20). In this sense, it is absolutely necessary to know (through the student’s perception) to what extent the socio-demographic variables that students present intervene and condition the learning process and its transfer. For this purpose, a purposive sample has been configured in which more than 1,400 4th ESO subjects (from Spain) have participated, with a significance level of 0.05 using a scale -original and unpublished- called EPECOCISO (Evaluation of the perception of social science competences -Álvarez, Trigueros, Miralles and Molina, 2020-).España (estadísticamente y a nivel europeo) ocupa las primeras posiciones de los países con mayores tasas de abandono escolar; y en esa misma línea diversos estudios (INE, 2020:155; Vaquero, 2011:3) constatan que los docentes en nuestro país consideran que la educación debe transformarse para hacer que todos los alumnos lleguen a sentirse protagonistas del proceso de aprendizaje; y que –además– todo lo aprendido pueda ser transferido para desarrollarse como ciudadanos en la medida que también satisfagan sus necesidades (Álvarez et al., 2020:4). En este sentido, resulta del todo necesario conocer (a través de la percepción del estudiante) en qué medida las variables sociodemográficas que presenta el alumnado intervienen y condicionan al proceso de aprendizaje y su transferencia. Para ello, se ha configurado un muestreo intencional en el que han participado más de 1400 sujetos de 4.º de ESO (de España), con un nivel de significatividad de 0,05 utilizando una escala –original e inédita– denominada EPECOCISO (Evaluación de la percepción sobre las competencias de ciencias sociales –Álvarez, Trigueros, Miralles y Molina, 2020:1-15–)

Physicochemical characterisation of graphene-ammonium lactate ionic liquid nanofluid.

A new series of nanofluids based on graphene dispersed in 2-hydroxyethylammonium lactate (ML) ionic liquid was developed. Concentrations of 0.1, 0.5 and 1 wt% of graphene were studied and these dispersions were stable after 2 months. Raman spectra showed a strong interaction between ML and graphene. The effect of the concentration of graphene and temperature on the viscoelastic behaviour and conductivity of the nanofluids was studied. An unexpected decrease in the viscosity was found with a low concentration of graphene due to the suppression of hydrogen bonding of the ionic liquid. Shear thinning effects appeared with higher concentrations of graphene and Ostwald and Herschel-Bulkley equations were used to describe the steady-state viscosity results. Creep-recovery tests were also performed, and the data were fitted to a complex Burgers model for the nanofluid with 1 wt% of graphene, with a 47 % of elastic response. The complexity of the model was related to the presence of different molecular arrangements in the nanofluid. An enhancement of the conductivity was observed with increasing values of the graphene concentration. The effect of temperature on viscosity and electrical conductivity was successfully modelled by using both Vogel-Fulcher-Tammann and Power Law equations. Electrochemical characterisation at room temperature was also carried out, finding an irreversible oxidation at 1 V only for the highest concentration (1 wt%). The concentration of percolation was estimated in the range of 0.5 to 1 wt% of graphene.The authors acknowledge the financial support of Ministerio de Economía y Competitividad and Agencia Estatal de Investigación (MINECO and AEI, Spain), EU-FEDER (MAT2017-85130-P, and PID2021-122169NB) and the Fundación Seneca, Agencia de Ciencia y Tecnología de la Región de Murcia (‘Ayuda a las Unidades y Grupos de Excelencia Científica de la Región de Murcia’; Grant # 19877/GERM/15). P.M. M.-R. is grateful to Fundación Séneca for FPI research grant (21574/FPI/21)

Measuring the Quality of Model-Driven Projects with NDT-Quality

Model-driven web engineering (MDWE) is a new paradigm which provides satisfactory results in the development of web software systems. However, as can be concluded from several research works, MDWE provokes traceability problems and the necessity of managing constraints in metamodel instances and transformation executions. The management of these aspects is usually executed manually in the most of MDWE approaches. Nevertheless, model-driven paradigm itself can offer suitable ways to manage them. This chapter presents NDT-Quality, an approach to measure the quality of web projects developed with NDT (navigational development techniques), and offers a view about the application of this tool in real web projects.Ministerio de Educación y Ciencia TIN2007-67843-C06-03Ministerio de Educación y Ciencia TIN2007-30391-