What good is Twitter? (for public service journalism?) New Polis Report

How can journalists working in public service newsrooms use social media to improve the quality of their work? Polis has a new report out by EBU Fellow Nadja Hahn that asks, What Use Is Twitter

What is the value of social media to public service journalism? New research project

We all know that using social media like Twitter and having online platforms such as blogs can enhance our journalism. But what if you have a particular public service brief, for example, working for a public service broadcaster

Promoter effects of alkali metal cations on the electrochemical reduction of carbon dioxide

The electrochemical reduction of CO_2 is known to be influenced by the identity of the alkali metal cation in the electrolyte; however, a satisfactory explanation for this phenomenon has not been developed. Here we present the results of experimental and theoretical studies aimed at elucidating the effects of electrolyte cation size on the intrinsic activity and selectivity of metal catalysts for the reduction of CO_2. Experiments were conducted under conditions where the influence of electrolyte polarization is minimal in order to show that cation size affects the intrinsic rates of formation of certain reaction products, most notably for HCOO–, C_2H_4, and C_2H_5OH over Cu(100)- and Cu(111)-oriented thin films, and for CO and HCOO– over polycrystalline Ag and Sn. Interpretation of the findings for CO_2 reduction was informed by studies of the reduction of glyoxal and CO, key intermediates along the reaction pathway to final products. Density functional theory calculations show that the alkali metal cations influence the distribution of products formed as a consequence of electrostatic interactions between solvated cations present at the outer Helmholtz plane and adsorbed species having large dipole moments. The observed trends in activity with cation size are attributed to an increase in the concentration of cations at the outer Helmholtz plane with increasing cation size

Halo histories versus galaxy properties at z = 0 II: large-scale galactic conformity

Using group catalogues from the Sloan Digital Sky Survey (SDSS) Data Release 7, we measure galactic conformity in the local universe. We measure the quenched fraction of neighbour galaxies around isolated primary galaxies, dividing the isolated sample into star-forming and quiescent objects. We restrict our measurements to scales >1 Mpc to probe the correlations between halo formation histories. Over the stellar mass range 10^(9.7) ≤ M*/M⊙ ≤ 10^(10.9), we find minimal evidence for conformity. We further compare these data to predictions of the halo age-matching model, in which the oldest galaxies are associated with the oldest haloes. For models with strong correlations between halo and stellar age, the conformity is too large to be consistent with the data. Weaker implementations of the age-matching model would not produce a detectable signal in SDSS data. We reproduce the results of Kauffmann et al., in which the star formation rates of neighbour galaxies are reduced around primary galaxies when the primaries are low star formers. However, we find this result is mainly driven by contamination in the isolation criterion; when removing the small fraction of satellite galaxies in the sample, the conformity signal largely goes away. Lastly, we show that small conformity signals, i.e. 2–5 per cent differences in the quenched fractions of neighbour galaxies, can be produced by mechanisms other than halo assembly bias. For example, if passive galaxies occupy more massive haloes than star-forming galaxies of the same stellar mass, a conformity signal that is consistent with recent measurements from PRIMUS (Berti et al.) can be produced

The Void Phenomenon Explained

We use high-resolution N-body simulations, combined with a halo occupation model of galaxy bias, to investigate voids in the galaxy distribution. Our goal is to address the 'void phenomenon' of Peebles (2001), which presents the observed dearth of faint galaxies in voids as a challenge to the current cosmology. In our model, galaxy luminosity is determined only as a function of dark matter halo mass. With this simple assumption, we demonstrate that large, empty voids of ~15 Mpc/h in diameter are expected even for galaxies seven magnitudes fainter than L*. The predictions of our model are in excellent agreement with several statistical measures; (i) the luminosity function of galaxies in underdense regions, (ii) nearest neighbor statistics of dwarf galaxies, (iii) the void probability function of faint galaxies. In the transition between filaments and voids in the dark matter, the halo mass function changes abruptly, causing the maximum galaxy luminosity to decrease by ~5 magnitudes over a range of ~1 Mpc/h. Thus the boundary between filaments and voids in the galaxy distribution is nearly as sharp for dwarfs as for ~L* objects. These results support a picture in which galaxy formation is driven predominantly by the mass of the host dark matter halo, and is nearly independent of the larger-scale halo environment. Further, they demonstrate that LCDM, combined with a straightforward bias model, naturally explains the existence of the void phenomenon.Comment: 8 pages, 5 figures, submitted to ApJ. citations update

The Predominance of Hydrogen Evolution on Transition Metal Sulfides and Phosphides under CO_2 Reduction Conditions: An Experimental and Theoretical Study

A combination of experiment and theory has been used to understand the relationship between the hydrogen evolution reaction (HER) and CO_2 reduction (CO_2R) on transition metal phosphide and transition metal sulfide catalysts. Although multifunctional active sites in these materials could potentially improve their CO_2R activity relative to pure transition metal electrocatalysts, under aqueous testing conditions, these materials showed a high selectivity for the HER relative to CO_2R. Computational results supported these findings, indicating that a limitation of the metal phosphide catalysts is that the HER is favored thermodynamically over CO_2R. On Ni-MoS_2, a limitation is the kinetic barrier for the proton–electron transfer to *CO. These theoretical and experimental results demonstrate that selective CO_2R requires electrocatalysts that possess both favorable thermodynamic pathways and surmountable kinetic barriers

The Predominance of Hydrogen Evolution on Transition Metal Sulfides and Phosphides under CO₂ Reduction Conditions: An Experimental and Theoretical Study

A combination of experiment and theory has been used to understand the relationship between the hydrogen evolution reaction (HER) and CO₂ reduction (CO₂R) on transition metal phosphide and transition metal sulfide catalysts. Although multifunctional active sites in these materials could potentially improve their CO₂R activity relative to pure transition metal electrocatalysts, under aqueous testing conditions, these materials showed a high selectivity for the HER relative to CO₂R. Computational results supported these findings, indicating that a limitation of the metal phosphide catalysts is that the HER is favored thermodynamically over CO₂R. On Ni-MoS₂, a limitation is the kinetic barrier for the proton–electron transfer to *CO. These theoretical and experimental results demonstrate that selective CO₂R requires electrocatalysts that possess both favorable thermodynamic pathways and surmountable kinetic barriers

Qualitative data sharing and re-use for socio-environmental systems research: A synthesis of opportunities, challenges, resources and approaches

Researchers in many disciplines, both social and natural sciences, have a long history of collecting and analyzing qualitative data to answer questions that have many dimensions, to interpret other research findings, and to characterize processes that are not easily quantified. Qualitative data is increasingly being used in socio-environmental systems research and related interdisciplinary efforts to address complex sustainability challenges. There are many scientific, descriptive and material benefits to be gained from sharing and re-using qualitative data, some of which reflect the broader push toward open science, and some of which are unique to qualitative research traditions. However, although open data availability is increasingly becoming an expectation in many fields and methodological approaches that work on socio-environmental topics, there remain many challenges associated the sharing and re-use of qualitative data in particular. This white paper discusses opportunities, challenges, resources and approaches for qualitative data sharing and re-use for socio-environmental research. The content and findings of the paper are a synthesis and extension of discussions that began during a workshop funded by the National Socio-Environmental Synthesis Center (SESYNC) and held at the Center Feb. 28-March 2, 2017. The structure of the paper reflects the starting point for the workshop, which focused on opportunities, challenges and resources for qualitative data sharing, and presents as well the workshop outputs focused on developing a novel approach to qualitative data sharing considerations and creating recommendations for how a variety of actors can further support and facilitate qualitative data sharing and re-use. The white paper is organized into five sections to address the following objectives: (1) Define qualitative data and discuss the benefits of sharing it along with its role in socio-environmental synthesis; (2) Review the practical, epistemological, and ethical challenges regarding sharing such data; (3) Identify the landscape of resources available for sharing qualitative data including repositories and communities of practice (4) Develop a novel framework for identifying levels of processing and access to qualitative data; and (5) Suggest roles and responsibilities for key actors in the research ecosystem that can improve the longevity and use of qualitative data in the future.This work was supported by the National Socio-Environmental Synthesis Center (SESYNC) under funding received from the National Science Foundation DBI-1052875