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

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

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

Comparison of Pretectal Genoarchitectonic Pattern between Quail and Chicken Embryos

Regionalization of the central nervous system is controlled by local networks of transcription factors that establish and maintain the identities of neuroepithelial progenitor areas and their neuronal derivatives. The conserved cerebral Bauplan of vertebrates must result essentially from conserved patterns of developmentally expressed transcription factors. We have previously produced detailed molecular maps for the alar plate of prosomere 1 (the pretectal region) in chicken (Ferran et al., 2007, 2008, 2009). Here we compare the early molecular signature of the pretectum of two closely related avian species of the family Phasianidae, Coturnix japonica (Japanese quail) and Gallus gallus (chicken), aiming to test conservation of the described pattern at a microevolutionary level. We studied the developmental pretectal expression of Bhlhb4, Dbx1, Ebf1, Gata3, Gbx2, Lim1, Meis1, Meis2, Pax3, Pax6, Six3, Tal2, and Tcf7l2 (Tcf4) mRNA, using in situ hybridization, and PAX7 immunohistochemistry. The genoarchitectonic profile of individual pretectal domains and strata was produced, using comparable section planes. Remarkable conservation of the combinatorial genoarchitectonic code was observed, fundamented in a tripartite anteroposterior subdivision. However, we found that at corresponding developmental stages the pretectal region of G. gallus was approximately 30% larger than that of C. japonica, but seemed relatively less mature. Altogether, our results on a conserved genoarchitectonic pattern highlight the importance of early developmental gene networks that causally underlie the production of homologous derivatives in these two evolutionarily closely related species. The shared patterns probably apply to sauropsids in general, as well as to more distantly related vertebrate species

A new Method for determining Compound Specific Carbon Isotope of Chlorinated Solvents in Porewater

A new method for the extraction of chlorinated solvents (CSs) from porewater with dimethylacetamide (DMA) used as a solvent and the determination of δ13C by gas chromatography-isotope ratio mass spectrometry (GC-IRMS) with solid-phase microextraction (SPME) are presented. This method was used for the determination of δ13C of chloroethenes and chloromethanes. The extraction of the CSs from porewater with DMA led to a minimal loss of mass of solvent and chlorinated compounds. The accuracy of the method was verified with the analysis of the pure injected compounds using elemental analyser - isotope ratio mass spectrometry (EA-IRMS). It has been effectively applied in a study area in saturated soil samples of a pollutant source zone of perchloroethylene (PCE) and trichloroethylene (TCE). The limit of quantification of the new method was 0.034 µg/g for PCE and TCE for 10-20 g of soil sample. This new method allows for compound-specific isotope analysis (CSIA) of CSs in porewater, which can be beneficial in sites where the identification of contamination sources and the behaviour of the contaminants are not clear

Natural attenuation of pools and plumes of carbon tetrachloride and chloroform in the transition zone to bottom aquitards and the microorganisms involved in their degradation

In the transition zone between aquifers and aquitards, DNAPL pools of carbon tetrachloride and chloroform accumulate because of heterogeneity in this zone. Natural attenuation occurs at pools and plumes, indicating that remediation might be possible. The aims of the study were: i) to assess the role of heterogeneity in the natural attenuation of these compounds, ii) determine degradation processes within this zone, and iii) identify dechlorinating microorganisms. For this, groundwater concentrations, redox-sensitive parameters, CSIA isotopic and DGGE molecular techniques were used. The main findings at depth of the transition zone were: (1) the important key control played by heterogeneity on natural attenuation of contaminants. (2) Heterogeneity caused the highly anoxic environment and dominant sulfate-reducing conditions, which accounts for more efficient natural attenuation. (3) Heterogeneity also explains that the transition zone constitutes an ecotone. (4) The bacteria size exclusion is governed by the pore throat threshold and determines the penetration of dechlorinating microorganisms into the finest sediments, which is relevant, since it implies the need to verify whether microorganisms proposed for bioremediation can penetrate these materials. (5) Reductive dechlorination caused the natural attenuation of contaminants in groundwater and porewater of fine sediments. In the case of carbon tetrachloride, it was an abiotic process biogenically mediated by A. suillum, a bacterium capable of penetrating the finest sediments. In the case of chloroform, it was a biotic process performed by a Clostridiales bacterium, which is unable to penetrate the finest materials. (6) Both microorganisms have potential to be biostimulated to dechlorinate contaminants in the source and the plume in the transition zone. These outcomes are particularly relevant given the longevity of DNAPL sources and have considerable environmental implications as many supply wells in industrial areas exploit aquifers contaminated by chlorinated solvents emerging from DNAPL pools accumulated on the low-conductivity layers in transition zones

Ontogenetic Expression of Sonic Hedgehog in the Chicken Subpallium

Sonic hedgehog (SHH) is a secreted signaling factor that is implicated in the molecular patterning of the central nervous system (CNS), somites, and limbs in vertebrates. SHH has a crucial role in the generation of ventral cell types along the entire rostrocaudal axis of the neural tube. It is secreted early in development by the axial mesoderm (prechordal plate and notochord) and the overlying ventral neural tube. Recent studies clarified the impact of SHH signaling mechanisms on dorsoventral patterning of the spinal cord, but the corresponding phenomena in the rostral forebrain are slightly different and more complex. This notably involves separate Shh expression in the preoptic part of the forebrain alar plate, as well as in the hypothalamic floor and basal plates. The present work includes a detailed spatiotemporal description of the singular alar Shh expression pattern in the rostral preoptic forebrain of chick embryos, comparing it with FoxG1, Dlx5, Nkx2.1, and Nkx2.2 mRNA expression at diverse stages of development. As a result of this mapping, we report a subdivision of the preoptic region in dorsal and ventral zones; only the dorsal part shows Shh expression. The positive area impinges as well upon a median septocommissural preoptic domain. Our study strongly suggests tangential migration of Shh-positive cells from the preoptic region into other subpallial domains, particularly into the pallidal mantle and the intermediate septum

The role of ecotones in the dehalogenation of chloroethenes in alluvial fan aquifers

The presence of ecotones in transition zones between geological strata (e.g. layers of gravel and sand interbedded with layers of silt in distal alluvial fan deposits) in aquifers plays a significant role in regulating the flux of matter and energy between compartments. Ecotones are characterised by steep physicochemical and biological gradients and considerable biological diversity. However, the link between organic pollutants and degradation potential in ecotones has scarcely been studied. The aim of this study is to relate the presence of ecotones with the dehalogenation of chloroethenes. A field site was selected where chloroethene contamination occurs in a granular aquifer with geological heterogeneities. The site is monitored by multilevel and conventional wells. Groundwater samples were analysed by chemical, isotopic, and molecular techniques. The main results were as follows: (1) two ecotones were characterised in the source area, one in the upper part of the aquifer and the second in the transition zone to the bottom aquitard, where the aged pool is located; (2) the ecotone located in the transition zone to the bottom aquitard has greater microbial diversity, due to higher geological heterogeneities; (3) both ecotones show the reductive dehalogenation of perchloroethylene and trichloroethylene; and (4) these ecotones are the main zones of the reductive dehalogenation of the pollutants, given the more reductive conditions at the centre of the plume. These findings suggest that ecotones are responsible for natural attenuation, where oxic conditions prevailed at the aquifer and bioremediation strategies could be applied more effectively in these zones to promote complete reductive dehalogenation

Juvenile hormone biosynthesis in adult Blattella germanica requires nuclear receptors Seven-up and FTZ-F1

In insects, the transition from juvenile development to the adult stage is controlled by juvenile hormone (JH) synthesized from the corpora allata (CA) glands. Whereas a JH-free period during the last juvenile instar triggers metamorphosis and the end of the growth period, the reappearance of this hormone after the imaginal molt marks the onset of reproductive adulthood. Despite the importance of such transition, the regulatory mechanism that controls it remains mostly unknown. Here, using the hemimetabolous insect Blattella germanica, we show that nuclear hormone receptors Seven-up-B (BgSvp-B) and Fushi tarazu-factor 1 (BgFTZ-F1) have essential roles in the tissue-and stage-specific activation of adult CA JH-biosynthetic activity. Both factors are highly expressed in adult CA cells. Moreover, RNAi-knockdown of either BgSvp-B or BgFTZ-F1 results in adult animals with a complete block in two critical JH-dependent reproductive processes, vitellogenesis and oogenesis. We show that this reproductive blockage is the result of a dramatic impairment of JH biosynthesis, due to the CA-specific reduction in the expression of two key JH biosynthetic enzymes, 3-hydroxy-3-methylglutaryl coenzyme A synthase-1 (BgHMG-S1) and HMG-reductase (BgHMG-R). Our findings provide insights into the regulatory mechanisms underlying the specific changes in the CA gland necessary for the proper transition to adulthood.Support for this research was provided by the Spanish MINECO (grants BFU2009-10571 and CGL2014-55786-P to D.M. and CGL2012-36251 and CGL2015-64727-P to X.B.) and by the Catalan Government (2014 SGR 619 to D.M., J.L.M. and X.B.). The research has also benefited from FEDER funds. F.B.-C. is a recipient of a pre-doctoral research Grant from the MICINN. C.N. is a recipient of a postdoctoral research grant from CSIC. O.M. is recipient of a pre-doctoral research grant from Generalitat de Catalunya.Peer Reviewe

Biotic and abiotic reductive dechlorination of chloroethenes in aquitards

Chlorinated solvents occur as dense nonaqueous phase liquid (DNAPL) or as solutes when dissolved in water. They are present inmany pollution sites in urban and industrial areas. They are toxic, carcinogenic, and highly recalcitrant in aquifers and aquitards. Inthe latter case, they migrate by molecular diffusion into the matrix. When aquitards are fractured, chlorinated solvents also penetrateas a free phase through the fractures. The main objective of this study was to analyze the biogeochemical processes occurring insidethe matrix surrounding fractures and in the joint-points zones. The broader implications of this objective derive from the fact that,incomplete natural degradation of contaminants in aquitards generates accumulation of daughter products. This causes steepconcentration gradients and back-diffusion fluxes between aquitards and high hydraulic conductivity layers. This offers opportunitiesto develop remediation strategies based, for example, on the coupling of biotic and reactive abiotic processes. The main resultsshowed: 1) Degradation occurred especially in the matrix adjacent to the orthogonal network of fractures and textural heterogeneities,where texture contrasts favored microbial development because these zones constituted ecotones. 2) A dechlorinating bacterium notbelonging to the Dehalococcoides genus, namely Propionibacterium acnes, survived under the high concentrations of dissolvedperchloroethene (PCE) in contact with the PCE-DNAPL and was able to degrade it to trichloroethene (TCE). Dehalococcoides genus was able to conduct PCE reductive dechlorination at least up to cis-1,2-dichloroethene (cDCE), which shows again the potential of themedium to degrade chloroethenes in aquitards. 3) Degradation of PCE in the matrix resulted from the coupling of reactive abiotic andbiotic processes¿in the first case, promoted by Fe sorbed to iron oxides, and in the latter case, related to dechlorinatingmicroorganisms. The dechlorination resulting from these coupling processes is slow and limited by the need for an adequate supply ofelectron donors