171 research outputs found
Analysis and evaluation of the largest 500 family firms’ websites through PLS-SEM technique
Dado que pocos estudios relacionan los aspectos técnicos de un sitio web corporativo con la facturación de una empresa, este documento tiene como objetivo examinar cómo la calidad de un sitio web corporativo influye en las redes sociales y la facturación de la empresa en grandes empresas familiares. También se prueba el efecto moderador y mediador de las redes sociales en las relaciones entre la calidad del sitio web y la rotación. Además, el documento realiza un análisis multigrupo para analizar las diferencias entre las empresas familiares con baja y alta concentración de propiedad familiar. La muestra utilizada en el estudio, los sitios web de las 500 empresas familiares más grandes de todo el mundo extraídos del Índice Global de Negocios Familiares compilados por la Universidad de St. Gallen, se analizaron utilizando modelos de ecuaciones estructurales de mínimos cuadrados parciales (PLS-SEM). Los resultados indican que tanto el efecto directo e indirecto de la calidad del sitio web en la rotación como el efecto moderador de las redes sociales en la relación entre la calidad del sitio web y la rotación fueron negativos y significativos. El análisis multigrupo revela algunas diferencias significativas entre ambos grupos. El estudio contribuye a la evaluación de la literatura del sitio web al explorar un nuevo sector de aplicación: las empresas familiares. Además, las empresas familiares más grandes deberían mejorar su presencia en las redes sociales para aumentar sus ventas.As few studies relate the technical aspects of a corporate website to a firm’s turnover, this paper aims to examine how the quality of a corporate website influences social networks and the company’s turnover in large family firms. The moderating and mediating effect of social networks on the relationships between website quality and turnover are also tested. In addition, the paper performs a multigroup analysis to analyze the differences between family businesses with low and high family ownership concentration. The sample used in the study, the largest 500 family firms’ websites around the globe extracted from The Global Family Business Index compiled by the University of St. Gallen, were analyzed using partial least squares–structural equation modeling (PLS-SEM). The results indicate that both the direct and indirect effect of website quality on turnover and the moderating effect of social networks in the relationship between website quality and turnover were negative and significant. The multigroup analysis reveals some significant differences between both groups. The study contributes to the evaluation of website literature by exploring a new sector of application: family businesses. Moreover, the largest family firms should improve their presence in social networks to increase their sales.• Junta de Extremadura y Fondos FEDER. AyudapeerReviewe
Stress Corrosion Cracking of X70 Pipeline Steel immersed in Synthetic Soil solution
A study of stress corrosion cracking (SCC) susceptibility of API X70 pipeline steel exposed to a synthetics oil solution at room temperature and atmospheric pressure through slow strain rate tests (SSRT) was carried out. Electrochemical noise (EN) measurements were recorded during SSRT in order to studythe SCC process. Additionally, polarization curves (PC) to evaluate the corrosion were carried out. Characteristic current transients were identified and assigned to different processes. EN measurements were analyzed in the time and frequency domain. The current stransients and localization index (LI) indicate that at the beginning of the test, in the elastic and yielding strength zone, the corrosion is dominant by not much transients with low amplitude and frequency. At the maximum strength (UTS) and before fracture, the presence of transients increased. The highest corrosion rate, obtained by Rn and Zn, were obtained in the plastic zone before of the facture. A superficial analysis obtained by scanning electron microscopy (SEM) was carried out on surface of the samples and it revealed the presence of some micro-cracking in the gage section of SSRT specimens. According to SCC index and SEM observations the X70 steel has low SCC susceptibility at the conditions studied
A simple formula to find the closest consistent matrix to a reciprocal matrix
Achieving consistency in pair-wise comparisons between decision elements given by experts or stakeholders is of paramount importance in decision-making based on the AHP methodology. Several alternatives to improve consistency have been proposed in the literature. The linearization method (Benitez et al., 2011 [10]), derives a consistent matrix based on an original matrix of comparisons through a suitable orthogonal projection expressed in terms of a Fourier-like expansion. We propose a formula that provides in a very simple manner the consistent matrix closest to a reciprocal (inconsistent) matrix. In addition, this formula is computationally efficient since it only uses sums to perform the calculations. A corollary of the main result shows that the normalized vector of the vector, whose components are the geometric means of the rows of a comparison matrix, gives the priority vector only for consistent matrices. (C) 2014 Elsevier Inc. All rights reserved.This work has been performed with the support of the project IDAWAS, DPI2009-11591 of the Direccion General de Investigacion del Ministerio de Ciencia e Innovacion (Spain), with the supplementary support of ACOMP/2010/146 of the Conselleria d'Educacio of the Generalitat Valenciana, and the support given to the first author by the Spanish project MTM2010-18539. The use of English in this paper was revised by John Rawlins; and the revision was funded by the Universitat Politecnica de Valencia, Spain.Benítez López, J.; Izquierdo Sebastián, J.; Pérez García, R.; Ramos Martínez, E. (2014). A simple formula to find the closest consistent matrix to a reciprocal matrix. Applied Mathematical Modelling. 38(15-16):3968-3974. https://doi.org/10.1016/j.apm.2014.01.007S396839743815-1
What drives growth of Scots pine in continental Mediterranean climates: drought, low temperatures or both?
Scots pine forests subjected to continental Mediterranean climates undergo cold winter temperatures and drought stress. Recent climatic trends towards warmer and drier conditions across the Mediterranean Basin might render some of these pine populations more vulnerable to drought-induced growth decline at the Southernmost limit of the species distribution. We investigated how cold winters and dry growing seasons drive the radial growth of Scots pine subject to continental Mediterranean climates by relating growth to climate variables at local (elevational gradient) and regional (latitudinal gradient) scales. Local climate-growth relationships were quantified on different time scales (5-, 10- and 15-days) to evaluate the relative role of elevation and specific site characteristics. A negative water balance driven by high maximum temperatures in June (low-elevation sites) and July (high-elevation sites) was the major constraint on growth, particularly on a 5- to 10-day time scale. Warm nocturnal conditions in January were associated with wider rings at the high-elevation sites. At the regional scale, Scots pine growth mainly responded positively to July precipitation, with a stronger association at lower elevations and higher latitudes. January minimum temperatures showed similar patterns but played a secondary role as a driver of tree growth. The balance between positive and negative effects of summer precipitation and winter temperature on radial growth depends on elevation and latitude, with low-elevation populations being more prone to suffer drought and heat stress; whereas, high-elevation populations may be favoured by warmer winter conditions. This negative impact of summer heat and drought has increased during the past decades. This interaction between climate and site conditions and local adaptations is therefore decisive for the future performance and persistence of Scots pine populations in continental Mediterranean climates. Forecasting changes in the Scots pine range due to climate change should include this site-related information to obtain more realistic predictions, particularly in Mediterranean rear-edge areas
Immune microenvironment characterisation and dynamics during anti-HER2-based neoadjuvant treatment in HER2-positive breast cancer
Despite their recognised role in HER2-positive (HER2+) breast cancer (BC), the composition, localisation and functional orientation of immune cells within tumour microenvironment, as well as its dynamics during anti-HER2 treatment, is largely unknown. We here investigate changes in tumour-immune contexture, as assessed by stromal tumour-infiltrating lymphocytes (sTILs) and by multiplexed spatial cellular phenotyping, during treatment with lapatinib-trastuzumab in HER2+ BC patients (PAMELA trial). Moreover, we evaluate the relationship of tumour-immune contexture with hormone receptor status, intrinsic subtype and immune-related gene expression. sTIL levels increase after 2 weeks of HER2 blockade in HR-negative disease and HER2-enriched subtype. This is linked to a concomitant increase in cell density of all four immune subpopulations (CD3+, CD4+, CD8+, Foxp3+). Moreover, immune contexture analysis showed that immune cells spatially interacting with tumour cells have the strongest association with response to anti-HER2 treatment. Subsequently, sTILs consistently decrease at the surgery in patients achieving pathologic complete response, whereas most residual tumours at surgery remain inflamed, possibly reflecting a progressive loss of function of T cells. Understanding the features of the resulting tumour immunosuppressive microenvironment has crucial implications for the design of new strategies to de-escalate or escalate systemic therapy in early-stage HER2+ BC
Biology and use of the Pacific fat sleeper Dormitator latifrons (Richardson, 1844): state of the art review
The present work is a review of the literature on the native Mexican fish Dormitator latifrons. The aim is to contribute to the integration and systematization of current knowledge to make it easier to identify existing knowledge gaps and breakthroghs Moreover, promote the successful cultivation and protection of this species whose consumption is increasing in Latin America. A review of the articles related to D. latifrons published in international and regional databases was carried out. The articles reviewed focus on taxonomy and systematics, phylogenetic, geographic distribution, ecology, physiology, reproduction, development, pathology, health, and the technologies used to cultivate this fish species. The conclusion is that, even though the cultivation of D. latifrons is of commercial interest in some countries, there are still significant gaps in our knowledge of biology and, consequently, the domestication potential of the species. Filling these gaps will require systematic research efforts on protecting natural populations and improving mass cultivation techniques.Fil: Vega Villasante, Fernando. Universidad de Guadalajara; MéxicoFil: Ruiz González, Luis E.. Universidad de Guadalajara; MéxicoFil: Chong Carrillo, Olimpia. Universidad de Guadalajara; MéxicoFil: Basto Rosales, Mao E. R.. Tecnológico Nacional de Bahía de Banderas; MéxicoFil: Palma Cancino, David J.. Universidad de Guadalajara; MéxicoFil: Tintos Gómez, Adrián. Universidad Tecnológica de Manzanillo; MéxicoFil: Montoya Martínez, Cynthia E.. Universidad de Guadalajara; MéxicoFil: Kelly Gutiérrez, Liza D.. Universidad de Guadalajara; MéxicoFil: Guerrero Galván, Saúl R.. Universidad de Guadalajara; MéxicoFil: Ponce Palafox, Jesús T.. Universidad Autónoma de Nayarit; MéxicoFil: Zapata, Ana. Universidad de Guadalajara; MéxicoFil: Musin, Gabriela Eliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Badillo Zapata, Daniel. Universidad de Guadalajara; Méxic
Firewood and hearths: Middle Palaeolithic woody taxa distribution from El Salt, stratigraphic unit Xb (Eastern Iberia)
Spatial analyses of Palaeolithic sites typically defined by hearth-related assemblages have been mostly based on lithic and faunal remains. By using spatial analysis methods in conjunction with analytical units with higher temporal resolution than typical stratigraphic units, synchronic and diachronic relationships between artifacts deposited during successive occupation events have been elucidated. Spatial analyses applied to archaeobotanical remains are scarce, and when available, are typically focused on carpological remains (seeds and fruits). The lack of spatial indicators among anthracological remains hampers obtaining significant data linked to the relationships established between the combustion features and scattered charcoal fragments recovered from excavated occupation surfaces. To address this problem, the charcoal assemblage from El Salt Stratigraphic Unit (SU) Xb (Archaeosedimentary Facies Association 2 [AFA 2]) is analyzed using spatial analysis methods. Results suggest that the integration of anthracological remains into a palimpsest dissection analyses is vital to better understand the relationship between combustion structures and activity areas. These results highlight the utility of spatial and statistical methods as important tools for future anthracological analyses to provide meaningful information related to taxa distribution and the last firewood used in combustion structures
Constraining the Ratio in TeV Cosmic Rays with Observations of the Moon Shadow by HAWC
An indirect measurement of the antiproton flux in cosmic rays is possible as
the particles undergo deflection by the geomagnetic field. This effect can be
measured by studying the deficit in the flux, or shadow, created by the Moon as
it absorbs cosmic rays that are headed towards the Earth. The shadow is
displaced from the actual position of the Moon due to geomagnetic deflection,
which is a function of the energy and charge of the cosmic rays. The
displacement provides a natural tool for momentum/charge discrimination that
can be used to study the composition of cosmic rays. Using 33 months of data
comprising more than 80 billion cosmic rays measured by the High Altitude Water
Cherenkov (HAWC) observatory, we have analyzed the Moon shadow to search for
TeV antiprotons in cosmic rays. We present our first upper limits on the
fraction, which in the absence of any direct measurements, provide
the tightest available constraints of on the antiproton fraction for
energies between 1 and 10 TeV.Comment: 10 pages, 5 figures. Accepted by Physical Review
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