Does the intensity in R&D generate start-up's growth?

The role of R&D investment on firm's performance is not clear from a theoretical perspective. While the effort in R&D activities conducted internally helps firms to develop the ability to identify, assimilate and apply external knowledge successfully (Cohen and Levinthal, 1990), such activities are costly (Nonaka, Toyama and Nagata, 2000) and take long time to produce new knowledge results (Zahra and Nielsen, 2002). Moreover, the uncertain economic value of new knowledge (Arrow, 1962) may delay the firm's growth. Accordingly, empirical evidence in this regard is mixed (Le, Bruce and Kroll, 2006; Díaz-Díaz; Coad and Rao, 2008; Kotabe, Srinivassan and Aulakh, 2002; Carayannis and Alexander, 2002; Lin, Lee and Hung, 2006). We argue that R&D activities do not have a direct effect on growth since not all new knowledge is economically relevant (Arrow, 1962). To be concise, the indirect relationship between R&D intensity and growth may be mediated by valuable and protected knowledge assets such as patents. We aim to contribute to the literature stream on innovation strategy and new venture growth by analyzing empirically these issues (i.e. direct effect of R&D intensity, and indirect effect of R&D intensity through the mediation of patents, on employment growth of new ventures). In doing so, we build on theoretical notions from the literature on resource-based view (Barney, 1991; Wernerfelt, 1984; Rumelt, 1984) and knowledge production function (Griliches, 1979). Data were collected in a cross sectional setting between February and April of 2008, through a survey addressed to 87 start-ups located in the Basque Country (Spain). According to our results, patents significantly and positively mediate the relation between R&D intensity and new venture growth. In particular, an increment of 1% of R&D intensity indirectly enhances new ventures' employment annual growth in a rate ranging from 0.22% to 0.36%. However, the direct effect of R&D intensity on growth is not significant. This empirical evidence provides entrepreneurs, promoters and policy-makers with an important implication: R&D activities require the mediation role of non-tradable knowledge assets such as patents or other modes of intellectual property in order to appropriate value from knowledge in terms of growth

Características estratigráficas y sedimentológicas del "Garumniense" en el sector de Ager (Pre-Pirineo, Lleida)

The depositional sequences of the Paleogene non-marine deposits in the Ager basin show the vertical succession of lacustrine sediments (Massana Formation), fluvial and floodplain deposits (Figuerola Fm), basin-wide lacustrine sediments (Milla Fm) and different successions of lacustrine-palustrine, floodplain, fluvial, sabkha and tidal deposits (Perauba Complex). These different sedimentary environments where developed during Upper Maastrichtian-Lower Paleogene time span. The fossil assemblages suggest that the K/T event occurred during the sedimentation of one of these sedimentary environments. Formerly it was assumed that the KJí boundary event was strictly related to a particular carbonate leve1 (Milla Fm), but now this event is related to the deposition of floodplain and fluvial sediments at the Upper portion of the Figuerola Fm. Accordingly with the new paleomagnetic and paleontologic data, the disappearance of the cretaceous charophytes and dinosaurs seems to have occurred in the studied area about two million years before K/T boundary event

Internal anatomy of an erg sequence from the aeolian-fluvial system of the De La Cuesta Formation (Paganzo Basin, northwestern Argentina)

Permian red beds of the De La Cuesta Formation in the Sierra de Narváez (Paganzo Basin, northwestern Argentina) are essentially composed of sandstones associated with mudstones and subordinate conglomerates. Facies distributions and stacking patterns indicate that these sediments resulted from the interaction between aeolian and ephemeral fluvial systems, and are represented by aeolian dune, dry aeolian interdune and Aeolian sand sheet, mudflat, wet aeolian interdune, and fluvial deposits. The De La Cuesta Formation is characterized by aeolian (erg) sequences alternating with non-aeolian (terminal alluvial fan - mudflat) sequences. Each erg sequence is bounded at its base by a regionally extensive sand-drift surface and at the top by an extinction surface. A number of architectural elements, including aeolian dunes limited by interdunes, grouped crescentic Aeolian dunes, longitudinal dunes, and draa with superimposed crescentic dunes are recognised in the erg sequences. The sand sea developed during phases of increasing aridity, whereas non-aeolian deposition might have occurred during more humid phases. Thus, the styles of aeolian-fluvial interaction are considered to result from cyclical climatic changes. Within the drier hemicycles, the rhythmic alternation between draa deposits and aeolian dune and interdune deposits indicates higher frequency cycles that could be attributed to subtle climatic oscillations and/ or changes in sand supply and availability. The development of the Permian sand sea in the inland Paganzo Basin seems to be related to the growth of a volcanic chain to the west. This topographic barrier separated the Paganzo Basin from the Chilean Basin, located along the western margin of Gondwana and characterised by shallow marine carbonate sedimentation. The correlation between the Permian erg and the shallow marine carbonates suggests a regional warming period during the Middle Permian in western Gondwana

El rol de la clase social, la educación y el desempleo parentales en el desarrollo cognitivo infantil

Objective: Assessing the association between socioeconomic gradient and cognitive development among children of a Spanish birth cohort aged 5-6 years from a gender perspective. Method: Cognitive development was assessed on 525 children aged 5-6 years in the INMA-Valencia cohort, with the Global Cognitive Score (GCS) from McCarthy Scales of Children’s Abilities. Information on social class, education level and employment was collected for both parents in addition to other sociodemographic factors, parental, family and child characteristics. The relationship between maternal and paternal socioeconomic gradient and cognitive development was assessed by linear regressions and comparing the variance explained by each indicator measured in the mother and father. Results: Maternal socioeconomic gradient indicators explained more variance on GCS than paternal. Maternal education and paternal social class had an important individual effect that stayed after adjusting by other parental, child and family determinants. In the multivariable analysis, maternal education, age and intelligence, paternal social class and the child’s age and sex were significantly associated with cognitive development. Conclusions: Diverse socioeconomic gradient factors have an important influence on cognitive development, maternal education being the strongest determinant. Policies should be implemented to mitigate the negative effects of this gradient on child development.Objetivo: Evaluar la asociación del gradiente socioeconómico y el desarrollo cognitivo en ni˜nos y ni˜nas de una cohorte espa˜nola a los 5-6 a˜nos de edad desde una perspectiva de género. Método: Se evaluó el desarrollo cognitivo en 525 ni˜nos/as de 5-6 a˜nos de la cohorte INMA-Valencia, mediante la Puntuación Global Cognitiva (PGC) de las Escalas McCarthy para ni˜nos y ni˜nas. Se recogió información de ambos progenitores sobre clase social, nivel de estudios y empleo, además de otros factores sociodemográficos, características parentales, de la familia y del ni˜no o la ni˜na. La relación entre el gradiente socioeconómico materno y paterno y el desarrollo cognitivo se evaluó mediante modelos de regresión lineal y comparando la varianza explicada por cada uno de los indicadores medidos en la madre y en el padre. Resultados: Los indicadores de gradiente socioeconómico de la madre explicaron más varianza del índice de PGC que los del padre. La educación materna y la clase social paterna tuvieron un importante efecto individual, que se mantuvo tras ajustar por otros determinantes de los progenitores, del ni˜no o de la ni˜na, y del entorno familiar. En el análisis multivariante, la educación, la edad y la inteligencia maternas, la clase social paterna, y la edad y el sexo del infante se asociaron significativamente con el desarrollo cognitivo. Conclusiones: Distintos factores del gradiente socioeconómico tienen influencia en el desarrollo cognitivo, siendo la educación materna el determinante más fuerte. Deberían implementarse políticas para paliar los efectos negativos de este gradiente en el desarrollo infantil

A characterization of finite multipermutation solutions of the Yang–Baxter equation

We prove that a finite non-degenerate involutive set-theoretic solution (X, r) of the Yang–Baxter equation is a multipermutation solution if and only if its structure group G(X, r) admits a left ordering or equivalently it is poly-Z.We prove that a finite non-degenerate involutive set-theoretic solution (X, r) of the Yang–Baxter equation is a multipermutation solution if and only if its structure group G(X, r) admits a left ordering or equivalently it is poly-Z

Molecular codes defining rostrocaudal domains in the embryonic mouse hypothalamus

The prosomeric model proposes that the hypothalamus is a rostral forebrain entity, placed ventral to the telencephalon and rostral to the diencephalon. Gene expression markers differentially label molecularly distinct dorsoventral progenitor domains, which represent continuous longitudinal bands across the hypothalamic alar and basal regions. There is also circumstantial support for a rostrocaudal subdivision of the hypothalamus into transverse peduncular (caudal) and terminal (rostral) territories (PHy, THy). In addition, there is evidence for a specialized acroterminal domain at the rostral midline of the terminal hypothalamus (ATD). The PHy and THy transverse structural units are presently held to form part of two hypothalamo-telencephalic prosomeres (hp1 and hp2, respectively), which end dorsally at the telencephalic septocommissural roof. PHy and THy have distinct adult nuclei, at all dorsoventral levels. Here we report the results of data mining from the Allen Developing Mouse Brain Atlas database, looking for genes expressed differentially in the PHy, THy and ATD regions of the hypothalamus at several developmental stages. This search allowed us to identify additional molecular evidence supporting the postulated fundamental rostrocaudal bipartition of the mouse hypothalamus into the PHy and THy, and also corroborated molecularly the singularity of the ATD. A number of markers were expressed in Thy (Fgf15, Gsc, Nkx6.2, Otx1, Zic1/5), but were absent in PHy, while other genes showed the converse pattern (Erbb4, Irx1/3/5, Lmo4, Mfap4, Plagl1, Pmch). We also identified markers that selectively label the ATD (Fgf8/10/18, Otx2, Pomc, Rax, Six6). On the whole, these data help to explain why, irrespective of the observed continuity of all dorsoventral molecular hypothalamic subdivisions across PHy and THy, different nuclear structures originate within each of these two domains, and also why singular structures arise at the ATD, e.g., the suprachiasmatic nuclei, the

A method for estimating the distribution of species susceptible to foot-and-mouth disease in the Kruger National Park Region

Landscape distribution of susceptible species is needed to model the spatial spread of infectious diseases. Our objective is to develop 2 individual species animal count maps - for African buffalo and domestic cattle susceptible to foot-and-mouth disease (FMD) in the Kruger National Park Region (KNPR) of the Republic of South Africa (RSA) - using retrospective census and land use data. The KNPR includes the Kruger National Park, Limpopo and Mpumalanga provinces. We applied dasymetric mapping methods to disaggregate animal population census data to a finer resolution using ancillary data. In this study, ancillary data used to define species distributions included stocking rate or carrying capacity and land suitability parameters, A geographical information system (GIS) was used to identify suitable land and vegetation locations (x,y coordinates) for each species. Covariate-specific animal counts were modelled using a Poisson distribution. The resulting animal count data was mapped and will be used to model FMD spread within the KNPR. (Résumé d'auteur

Quadrature and polarization squeezing in a dispersive optical bistability model

We theoretically study quadrature and polarization squeezing in dispersive optical bistability through a vectorial Kerr cavity model describing a nonlinear cavity filled with an isotropic chi(3) medium in which self-phase and cross-phase modulation, as well as four--wave mixing, occur. We derive expressions for the quantum fluctuations of the output field quadratures as a function of which we express the spectrum of fluctuations of the output field Stokes parameters. We pay particular attention to study how the bifurcations affecting the non-null linearly polarized output mode squeezes the orthogonally polarized vacuum mode, and show how this produces polarization squeezing.Comment: 10 text pages + 12 figure