Joint inversion estimate of regional glacial isostatic adjustment in Antarctica considering a lateral varying Earth structure (ESA STSE Project REGINA)

A major uncertainty in determining the mass balance of the Antarctic ice sheet from measurements of satellite gravimetry, and to a lesser extent satellite altimetry, is the poorly known correction for the ongoing deformation of the solid Earth caused by glacial isostatic adjustment (GIA). Although much progress has been made in consistently modelling the ice-sheet evolution throughout the last glacial cycle, as well as the induced bedrock deformation caused by these load changes, forward models of GIA remain ambiguous due to the lack of observational constraints on the ice sheet's past extent and thickness and mantle rheology beneath the continent. As an alternative to forward modelling GIA, we estimate GIA from multiple space-geodetic observations: GRACE, Envisat/ICESat and GPS. Making use of the different sensitivities of the respective satellite observations to current and past surface mass (ice mass) change and solid Earth processes, we estimate GIA based on viscoelastic response functions to disc load forcing. We calculate and distribute the viscoelastic response functions according to estimates of the variability of lithosphere thickness and mantle viscosity in Antarctica. We compare our GIA estimate with published GIA corrections and evaluate its impact in determining the ice mass balance in Antarctica from GRACE and satellite altimetry. Particular focus is applied to the Amundsen Sea Sector in West Antarctica, where uplift rates of several cm/yr have been measured by GPS. We show that most of this uplift is caused by the rapid viscoelastic response to recent ice-load changes, enabled by the presence of a low-viscosity upper mantle in West Antarctica. This paper presents the second and final contribution summarizing the work carried out within a European Space Agency funded study, REGINA, (www.regina-science.eu)

Are spherulitic lacustrine carbonates an expression of large-scale mineral carbonation? : A case study from the East Kirkton Limestone, Scotland

BP Exploration Co. is thanked for funding, and particularly the Carbonate Team for supporting this research and for fruitful discussions. West Lothian Council and Scottish Natural Heritage are thanked for allowing access and permission for sampling the site. The Core Store Team at BGS Keyworth is particularly acknowledged for their assistance. Mark Anderson, Tony Sinclair (University of Hull), and Bouk Lacet (VU University Amsterdam) are thanked for technical support. Anne Kelly (SUERC) for carrying out the Strontium Isotope analyses. Mark Tyrer is thanked for his advice on PHREEQC modelling.Peer reviewedPostprin

Historia antigua de San Ramón de Alajuela (1000 A.C.-1550 D.C.)

Las investigaciones arqueológicas desarrolladas en la región de SanRamón desde las década de 1970 tienen su continuidad con laprospección sistemática y total llevada a cabo en el año 2007.Gracias a la misma ha sido posible delinear una historiasociopolítica para la región que abarca desde el año 1000 a.C. hastatiempos de la conquista europea. A lo largo de su historiaprecolombina los habitantes de San Ramón vivieronmayoritariamente de forma dispersa, de forma independiente, solodespués del 300 d.C. la población aumenta fuertemente ycomienzan a formarse caseríos y aldeas. Para el 900 d.C. surge enla región una estructura social cacical.In 2007 a systematic, full coverage survey was carried on in SanRamón de Alajuela region. The survey provided a large amount ofinformation about the pre-Columbian sociopolitical trajectory of thesocieties that developed in the region. Settlement and communityformation and collapse has been accounted, as well as demographicvariations, period by period. Throughout its history, San Ramonpre-Columbian inhabitants lived mostly in small scattered houses;only after 300 A.D. population increased sharply and began to formhamlets and villages. Around 900 A.D. a chiefly social structurearose in the region.UCR::Vicerrectoría de Docencia::Ciencias Sociales::Facultad de Ciencias Sociales::Escuela de Antropologí

Photophysical properties of [(norharmane)Re(CO)3 (L)]+ complexes (L = bpy, phen or dppz). Redox behavior of the excited states and their interaction with Calf Thymus DNA

The photochemical and photophysical properties of [(nHo)Re(CO)3(L)]+ complexes, where nHo = 9H-pyrido[3,4-b]indole and L = 2,2′ bipyridine (bpy), 1,10 phenantroline (phen) or dipyridil[3,2-a:2′3′-c]phenazine (dppz) were investigated by Laser Flash Photolysis (LFF) and Pulse Radiolysis (PR) techniques. While complexes with L = bpy or phen show absorption transients compatible with MLCTRe→L excited states, [(nHo)Re(CO)3(dppz)]+ showed an excited state assignable to a dppz-centered, 3ππ*dppz. In aqueous solutions, the last complex does not generate any absorption transient. However, when Calf thymus DNA was added, the same absorption spectrum was obtained. These results suggest that this complex can intercalate into DNA. The species generated in either reductive or oxidative conditions in LFF experiments were compared with those obtained in PR. Also, the quenching rate constants (kq) of the excited states with MV2+ were calculated. The intercalation of the [(nHo)Re(CO)3(dppz)]+ into DNA, increases kq ∼100 times. This result is rationalized in terms of the conditions created by the intercalation using the biopolymer as a well-organized matrix.Fil: Maisuls, Iván. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Cabrerizo, Franco Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Lappin, Alexander G.. University of Notre Dame-Indiana; Estados UnidosFil: Ruiz, Gustavo Teodosio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Ferraudi, Guillermo J.. University of Notre Dame-Indiana; Estados Unido

Variation in the Structure and Role of Religious Institutions: Examples from pre-Columbian America

Research on religious behavior has stressed its character as a cognitive complex that evolved during the Pleistocene to incentivize prosocial behavior and serves roughly similar population management roles regardless of social context. To explore this idea, we reconstructed religious institutional structure for three pre- Columbian societies using a key feature or religious organization: the basal congregation size—a critical axis of population management and for the creation of shared communal identities. Results show that in places where populations could fission to avoid intra-community conflict, religious institutions show no real evidence of internal community management. In locations where large towns meant more internal conflict, religious institutions mapped themselves over the extended family, creating small congregations that provided the mid-level organizational tiers necessary to support larger communities. Finally, for populations organized into regional polities, religious institutions used large ritual assemblies and conspicuous paraphernalia to invoke our Pleistocene cognitive predispositions for altruistic and cooperative behavior towards close-kin, but redirected them towards the large, non-kin religious community. This variation highlights the malleable and reactive nature of religious institutions, which interact quite differently with their constituent members or their cognitive predispositions depending on the social needs they look to resolve.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Sociales::Centro de Investigaciones Antropológicas (CIAN)UCR::Vicerrectoría de Docencia::Ciencias Sociales::Facultad de Ciencias Sociales::Escuela de Antropologí

Requirement of Two Acyltransferases for 4-O-Acylation during Biosynthesis of Harzianum A, an Antifungal Trichothecene Produced by Trichoderma arundinaceum

Trichothecenes are sesquiterpenoid toxins produced by multiple fungi, including plant pathogens, entomopathogens, and saprotrophs. Most of these fungi have the acyltransferase-encoding gene tri18. Even though its function has not been determined, tri18 is predicted to be involved in trichothecene biosynthesis because of its pattern of expression and its location near other trichothecene biosynthetic genes. Here, molecular genetic, precursor feeding, and analytical chemistry experiments indicate that in the saprotroph Trichoderma arundinaceum the tri18-encoded acyltransferase (TRI18) and a previously characterized acyltransferase (TRI3) are required for conversion of the trichothecene biosynthetic intermediate trichodermol to harzianum A, an antifungal trichothecene analog with an octa-2,4,6-trienedioyl acyl group. On the basis of the results, we propose that TRI3 catalyzes trichothecene 4-O-acetylation, and subsequently, TRI18 catalyzes replacement of the resulting acetyl group with octa-2,4,6-trienedioyl to form harzianum A. Thus, the findings provide evidence for a previously unrecognized two-step acylation process during trichothecene biosynthesis in T. arundinaceum and possibly other fungiSIThe Spanish Ministry of Economy and Competitiveness supported this work (MINECO-AGL2015-70671-C2-2-R to S.G.), and the University of León granted L.L. a fellowshi

The importance of non-LTE models for the interpretation of observations of interstellar NO

Context. The ALMA and Herschel missions promise to deliver data of high spatial and spectral resolution at far-infrared and submillimeter wavelengths. Modeling these data will require the knowledge of accurate radiative and collisional rates for species of astrophysical interest. Aims. We calculate the rotational excitation rate coefficients of NO in collisions with He and check the validity of the LTE approach in interpreting observations of rotational lines of NO. Methods. State-to-state rate coefficients between the 360 lowest hyperfine levels of NO were calculated using the M(J) randomizing limit method for temperatures from 10 K to 350 K. We performed calculations of the excitation of NO using the new rate coefficients using a large velocity gradient (LVG) radiative transfer code. Results. The critical densities of the lines are found to be at greater than or similar to 10(15) cm(-3). The low dipole moment of NO ensures that the line emission is optically thin up to column densities of similar to 10(15) cm(-2). Lines in the ground (Omega = 1/2) state are readily detectable in typical conditions (N(NO) = 10(13) cm(-2); T = 10-30 K), whereas lines in the excited Omega = 3/2 state are observed only in warm (T > 50 K) regions with higher column densities (N(NO) = 10(14) cm(-2)). Line ratios of NO may well be used to constrain the ambient temperature and/or density. Conclusions. The new rate coefficients will help significantly in interpreting NO emission lines observed with current and future telescopes, and enable this molecule to become a powerful astrophysical tool

Novel windows for “solar commodities”: a device for CO2 reduction using plasmonic catalyst activation

Producción CientíficaA novel plasmonic reactor concept is proposed and tested to work as a visible energy harvesting device while allowing reactions to transform CO2 to be carried out. Particularly the reverse water gas shift (RWGS) reaction has been tested as a means to introduce renewable energy into the economy. The development of the new reactor concept involved the synthesis of a new composite capable of plasmonic activation with light, the development of an impregnation method to create a single catalyst reactor entity, and finally the assembly of a reaction system to test the reaction. The composite developed was based on a Cu/ZnO catalyst dispersed into transparent aerogels. This allows efficient light transmission and a high surface area for the catalyst. An effective yet simple impregnation method was developed that allowed introduction of the composites into glass microchannels. The activation of the reaction was made using LEDs that covered all the sides of the reactor allowing a high power delivery. The results of the reaction show a stable process capable of low temperature transformations