Carbon Sinks and Reservoirs: The Value of Permanence and Role of Discounting

Scientists are enthusiastic about storing carbon in terrestrial sinks and geological reservoirs in order to obviate the need for lifestyle-changing reductions in fossil-fuel use. Estimating relative costs of various options depends on how permanence is assessed and whether physical carbon is discounted. We demonstrate that, in carbon markets, terrestrial sinks credits cannot be traded one-for-one for emission reduction credits and the conversion factor would depend on how long sinks keep CO2 out of the atmosphere as compared with emission reductions and, discounting physical carbon. As a result, the authority could not determine a conversion factor and the market would be required to do so.climate change, carbon offset, carbon sinks, discounting physical carbon

II. Apples to apples A2A^2: cluster selection functions for next-generation surveys

We present the cluster selection function for three of the largest next-generation stage-IV surveys in the optical and infrared: Euclid-Optimistic, Euclid-Pessimistic and the Large Synoptic Survey Telescope (LSST). To simulate these surveys, we use the realistic mock catalogues introduced in the first paper of this series. We detected galaxy clusters using the Bayesian Cluster Finder (BCF) in the mock catalogues. We then modeled and calibrated the total cluster stellar mass observable-theoretical mass ($M^*_{\rm CL}-M_{\rm h}$) relation using a power law model, including a possible redshift evolution term. We find a moderate scatter of $\sigma_{M^*_{\rm CL} | M_{\rm h}}$ of 0.124, 0.135 and 0.136 $\rm dex$ for Euclid-Optimistic, Euclid-Pessimistic and LSST, respectively, comparable to other work over more limited ranges of redshift. Moreover, the three datasets are consistent with negligible evolution with redshift, in agreement with observational and simulation results in the literature. We find that Euclid-Optimistic will be able to detect clusters with $>80\%$ completeness and purity down to $8\times10^{13} h^{-1} M_{\odot}$ up to $z<1$. At higher redshifts, the same completeness and purity are obtained with the larger mass threshold of $2\times10^{14} h^{-1} M_{\odot}$ up to $z=2$. The Euclid-Pessimistic selection function has a similar shape with $\sim10\%$ higher mass limit. LSST shows $\sim 5\%$ higher mass limit than Euclid-Optimistic up to $z<0.7$ and increases afterwards, reaching values of $2\times10^{14} h^{-1} M_{\odot}$ at $z=1.4$. Similar selection functions with only $80\%$ completeness threshold have been also computed. The complementarity of these results with selection functions for surveys in other bands is discussed.Comment: 13 pages, 10 figures, accepted for publication in MNRA

Conservation Payments under Risk: A Stochastic Dominance Approach

Conservation payments can be used to preserve forest and agroforest systems in developing countries. To explain landowners’ land-use decisions and determine the appropriate conservation payments, it is necessary to focus on risk associated with agricultural price and yield volatility. A theoretical framework is provided for assessing land-use allocation problems under risk and setting risk-efficient conservation payments when returns are not necessary normally distributed. Stochastic dominance rules are used to derive conditions for determining the conservation payments required to guarantee that the environmentally-preferred land use dominates, even when land uses are not considered to be mutually exclusive. An empirical application to shaded-coffee protection in the biologically important El Chocó region of West Ecuador shows that conservation payments required for preserving shaded-coffee areas are much higher than those calculated under the assumption of risk-neutrality. Further, the extant distribution of land has a strong impact on the required conservation payments.risk, conservation payments, land allocation, stochastic dominance, agroforest systems, portfolio diversification

Conservation Payments under Risk: A Stochastic Dominance Approach

Conservation payments can be used to preserve forest and agroforest systems. To explain landowners’ land-use decisions and determine appropriate conservation payments, it is necessary to focus on revenue risk. Marginal conditional stochastic dominance rules are used to derive conditions for determining the conservation payments required to guarantee that the environmentally-preferred land use dominates. An empirical application to shaded-coffee protection in the biologically important Chocó region of West-Ecuador shows that conservation payments required for preserving shaded-coffee areas are much higher than those calculated under risk-neutral assumptions. Further, the extant distribution of land has strong impacts on the required payments.agroforest systems, conservation payments, land allocation, portfolio diversification, risk, stochastic dominance

Confinement of neutral fermions by a pseudoscalar double-step potential in (1+1) dimensions

The problem of confinement of neutral fermions in two-dimensional space-time is approached with a pseudoscalar double-step potential in the Dirac equation. Bound-state solutions are obtained when the coupling is of sufficient intensity. The confinement is made plausible by arguments based on effective mass and anomalous magnetic interaction.Comment: 8 pages, 1 figur

Mergers and the outside-in formation of dwarf spheroidals

We use a cosmological simulation of the formation of the Local Group to explore the origin of age and metallicity gradients in dwarf spheroidal galaxies. We find that a number of simulated dwarfs form "outside-in", with an old, metal-poor population that surrounds a younger, more concentrated metal-rich component, reminiscent of dwarf spheroidals like Sculptor or Sextans. We focus on a few examples where stars form in two populations distinct in age in order to elucidate the origin of these gradients. The spatial distributions of the two components reflect their diverse origin; the old stellar component is assembled through mergers, but the young population forms largely in situ. The older component results from a first episode of star formation that begins early but is quickly shut off by the combined effects of stellar feedback and reionization. The younger component forms when a late accretion event adds gas and reignites star formation. The effect of mergers is to disperse the old stellar population, increasing their radius and decreasing their central density relative to the young population. We argue that dwarf-dwarf mergers offer a plausible scenario for the formation of systems with multiple distinct populations and, more generally, for the origin of age and metallicity gradients in dwarf spheroidals.Comment: 10 pages, 8 figures, Accepted for publication in MNRA

Exact solution of the two-dimensional Dirac oscillator

In the present article we have found the complete energy spectrum and the corresponding eigenfunctions of the Dirac oscillator in two spatial dimensions. We show that the energy spectrum depends on the spin of the Dirac particle.Comment: revtex, 6pp. IVIC-CFLE 93/0

Investigación en innovación tecnológica: un estudio bibliométrico de Revista Europea de Dirección y Economía de la Empresa

ResumenEste trabajo tiene como objetivo analizar la evolución de las investigaciones relativas a los procesos de innovación tecnológica en las empresas. Para ello, hemos realizado un estudio bibliométrico de Revista Europea de Dirección y Economía de la Empresa, que es una de las principales publicaciones españolas sobre dirección de empresas. Se han analizado 63 artículos sobre innovación tecnológica publicados en la Revista en el periodo de estudio, que comprende los primeros 20 volúmenes (1992–2011). Se han aplicado diferentes métodos y técnicas bibliométricas (indicadores de actividad, relacionales de primera y segunda generación) que nos han permitido reflejar la evolución del nivel de publicaciones, identificar las universidades y los autores más productivos, determinar las metodologías empleadas, conocer las redes de cooperación existentes entre ellos y los principales temas de investigación tratados.AbstractThe aim of this paper is to analyze the evolution of research on technological innovation processes in companies. We have performed a bibliometric study of Revista Europea de Dirección y Economía de la Empresa, which is one of the leading Spanish journals on Company Management. We have analyzed 63 articles on technological innovation published in the mentioned journal for a study period covering the first 20 volumes of the journal (1992–2011). Different bibliometric methods and techniques have been applied (activity, first and second generation relational indicators) that have allowed us to describe the evolution of publication activity and to identify the most productive authors and universities, the most frequently used methodologies, the cooperation networks among them and the main subjects researched

Influence of single-neutron stripping on near-barrier ⁶He+²⁰⁸Pb and ⁸He+²⁰⁸Pb elastic scattering

The influence of single-neutron stripping on the near-barrier elastic scattering angular distributions for the 6,8He+208Pb systems is investigated through coupled reaction channels (CRC) calculations fitting recently published data to explore the differences in the absorptive potential found in the scattering of these two neutron-rich nuclei. The inclusion of the coupling reduces the elastic cross section in the Coulomb-nuclear interference region for 8He scattering, whereas for 6He its major impact is on the large-angle elastic scattering. The real and imaginary dynamic polarization potentials are obtained by inverting the CRC elastic scattering S-matrix elements. These show that the main absorptive features occur between 11 and 12 fm for both projectiles, while the attractive features are separated by about 1 fm, with their main structures occurring at 10.5 fm for 6He and 11.5 fm for 8He