86 research outputs found
Essays on the Economics of Ethnolinguistic Differences
In this dissertation, I study the origins and economic consequences of ethnolinguistic differences. To quantify these differences, I construct a lexicostatistical measure of linguistic distance. I use this measure to study two different outcomes: ethnic politics and cross-country idea flows. I then take the economic importance of ethnolinguistic differences as given, and explore the geographic foundation of these differences.
In chapter 1, I document evidence of ethnic favoritism in 35 sub-Saharan countries. I use lexicostatistical distance to quantify the similarity between an ethnic group and the national leader's ethnic identity. I find that a one standard deviation increase in similarity yields a 2 percent increase in group-level GDP per capita. I then use the continuity of lexicostatistical similarity to show that favoritism exists among groups that are not coethnic to the leader, where the mean effect of non-coethnic similarity is one quarter the size of the coethnic effect. I relate these results to the literature on coalition building, and provide evidence that ethnicity is a guiding principle behind high-level government appointments.
In chapter 2, I use book translations data to capture cross-country idea flows. It has been conjectured that income gaps are smaller between ancestrally related countries because they communicate more ideas. I provide empirical support for this link and a deeper understanding of the hypothesized mechanism: population differences do exhibit a negative relationship with the diffusion of ideas, with the caveat that this negative relationship operates across linguistic lines. After accounting for the linguistic distance between two countries, I find that dissimilar populations communicate more ideas.
In chapter 3, I study the geographic origins of ethnolinguistic differences. I construct a novel dataset to examine the border regions of neighbouring ethnolinguistic groups, together with variation in the set of potentially cultivatable crops at the onset of the Columbian Exchange, to estimate how agricultural diversity impacts linguistic differences between neighbouring groups. I find that ethnic groups separated across agriculturally diverse regions are more similar in language than groups separated across homogeneous agricultural regions. I propose that historical trade in agriculturally diverse regions is the mechanism by which group similarities are preserved
Functional Independent Scaling Relation for ORR/OER Catalysts
A widely
used adsorption energy scaling relation between OH* and
OOH* intermediates in the oxygen reduction reaction (ORR) and oxygen
evolution reaction (OER), has previously been determined using density
functional theory and shown to dictate a minimum thermodynamic overpotential
for both reactions. Here, we show that the oxygen–oxygen bond
in the OOH* intermediate is, however, not well described with the
previously used class of exchange-correlation functionals. By quantifying
and correcting the systematic error, an improved description of gaseous
peroxide species versus experimental data and a reduction in calculational
uncertainty is obtained. For adsorbates, we find that the systematic
error largely cancels the vdW interaction missing in the original
determination of the scaling relation. An improved scaling relation,
which is fully independent of the applied exchange–correlation
functional, is obtained and found to differ by 0.1 eV from the original.
This largely confirms that, although obtained with a method suffering
from systematic errors, the previously obtained scaling relation is
applicable for predictions of catalytic activity
Combining theory and experiment in electrocatalysis: Insights into materials design
Better living through water-splitting
Chemists have known how to use electricity to split water into hydrogen and oxygen for more than 200 years. Nonetheless, because the electrochemical route is inefficient, most of the hydrogen made nowadays comes from natural gas. Seh
et al.
review recent progress in electrocatalyst development to accelerate water-splitting, the reverse reactions that underlie fuel cells, and related oxygen, nitrogen, and carbon dioxide reductions. A unified theoretical framework highlights the need for catalyst design strategies that selectively stabilize distinct reaction intermediates relative to each other.
Science
, this issue p.
10.1126/science.aad4998
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Detection and Production of Methane Hydrate
This project seeks to understand regional differences in gas hydrate systems from the perspective of as an energy resource, geohazard, and long-term climate influence. Specifically, the effort will: (1) collect data and conceptual models that targets causes of gas hydrate variance, (2) construct numerical models that explain and predict regional-scale gas hydrate differences in 2-dimensions with minimal 'free parameters', (3) simulate hydrocarbon production from various gas hydrate systems to establish promising resource characteristics, (4) perturb different gas hydrate systems to assess potential impacts of hot fluids on seafloor stability and well stability, and (5) develop geophysical approaches that enable remote quantification of gas hydrate heterogeneities so that they can be characterized with minimal costly drilling. Our integrated program takes advantage of the fact that we have a close working team comprised of experts in distinct disciplines. The expected outcomes of this project are improved exploration and production technology for production of natural gas from methane hydrates and improved safety through understanding of seafloor and well bore stability in the presence of hydrates. The scope of this project was to more fully characterize, understand, and appreciate fundamental differences in the amount and distribution of gas hydrate and how this would affect the production potential of a hydrate accumulation in the marine environment. The effort combines existing information from locations in the ocean that are dominated by low permeability sediments with small amounts of high permeability sediments, one permafrost location where extensive hydrates exist in reservoir quality rocks and other locations deemed by mutual agreement of DOE and Rice to be appropriate. The initial ocean locations were Blake Ridge, Hydrate Ridge, Peru Margin and GOM. The permafrost location was Mallik. Although the ultimate goal of the project was to understand processes that control production potential of hydrates in marine settings, Mallik was included because of the extensive data collected in a producible hydrate accumulation. To date, such a location had not been studied in the oceanic environment. The project worked closely with ongoing projects (e.g. GOM JIP and offshore India) that are actively investigating potentially economic hydrate accumulations in marine settings. The overall approach was fivefold: (1) collect key data concerning hydrocarbon fluxes which is currently missing at all locations to be included in the study, (2) use this and existing data to build numerical models that can explain gas hydrate variance at all four locations, (3) simulate how natural gas could be produced from each location with different production strategies, (4) collect new sediment property data at these locations that are required for constraining fluxes, production simulations and assessing sediment stability, and (5) develop a method for remotely quantifying heterogeneities in gas hydrate and free gas distributions. While we generally restricted our efforts to the locations where key parameters can be measured or constrained, our ultimate aim was to make our efforts universally applicable to any hydrate accumulation
Assessment of an in vitro whole cigarette smoke exposure system: The Borgwaldt RM20S 8-syringe smoking machine
<p>Abstract</p> <p>Background</p> <p>There have been many recent developments of <it>in vitro </it>cigarette smoke systems closely replicating <it>in vivo </it>exposures. The Borgwaldt RM20S smoking machine (RM20S) enables the serial dilution and delivery of cigarette smoke to exposure chambers for <it>in vitro </it>analyses. In this study we have demonstrated reliability and robustness testing of the RM20S in delivering smoke to <it>in vitro </it>cultures using an in-house designed whole smoke exposure chamber.</p> <p>Results</p> <p>The syringe precision and accuracy of smoke dose generated by the RM20S was assessed using a methane gas standard and resulted in a repeatability error of ≤9%. Differential electrical mobility particle spectrometry (DMS) measured smoke particles generated from reference 3R4F cigarettes at points along the RM20S. 53% ± 5.9% of particles by mass reached the chamber, the remainder deposited in the syringe or connecting tubing and ~16% deposited in the chamber. Spectrofluorometric quantification of particle deposition within chambers indicated a positive correlation between smoke concentration and particle deposition. <it>In vitro </it>air-liquid interface (ALI) cultures (H292 lung epithelial cells), exposed to whole smoke (1:60 dilution (smoke:air, equivalent to ~5 μg/cm<sup>2</sup>)) demonstrated uniform smoke delivery within the chamber.</p> <p>Conclusions</p> <p>These results suggest this smoke exposure system is a reliable and repeatable method of generating and exposing ALI <it>in vitro </it>cultures to cigarette smoke. This system will enable the evaluation of future tobacco products and individual components of cigarette smoke and may be used as an alternative <it>in vitro </it>tool for evaluating other aerosols and gaseous mixtures such as air pollutants, inhaled pharmaceuticals and cosmetics.</p
An evaluation of the effectiveness of a community mentoring service for socially isolated older people: a controlled trial
<p>Abstract</p> <p>Background</p> <p>Social isolation affects a significant proportion of older people and is associated with poor health outcomes. The current evidence base regarding the effectiveness of interventions targeting social isolation is poor, and the potential utility of mentoring for this purpose has not previously been rigorously evaluated. The purpose of this study was to examine the effectiveness of a community-based mentoring service for improving mental health, social engagement and physical health for socially isolated older people.</p> <p>Methods</p> <p>This prospective controlled trial compared a sample of mentoring service clients (intervention group) with a matched control group recruited through general practice. One hundred and ninety five participants from each group were matched on mental wellbeing and social activity scores. Assessments were conducted at baseline and at six month follow-up. The primary outcome was the Short Form Health Survey v2 (SF-12) mental health component score (MCS). Secondary outcomes included the SF-12 physical health component score (PCS), EuroQol EQ-5D, Geriatric Depression Score (GDS-10), social activity, social support and morbidities.</p> <p>Results</p> <p>We found no evidence that mentoring was beneficial across a wide range of participant outcomes measuring health status, social activity and depression. No statistically significant between-group differences were observed at follow-up in the primary outcome (p = 0.48) and in most secondary outcomes. Identifying suitable matched pairs of intervention and control group participants proved challenging.</p> <p>Conclusions</p> <p>The results of this trial provide no substantial evidence supporting the use of community mentoring as an effective means of alleviating social isolation in older people. Further evidence is needed on the effectiveness of community-based interventions targeting social isolation. When using non-randomised designs, there are considerable challenges in the recruitment of suitable matches from a community sample.</p> <p>Trial registration</p> <p>SCIE Research Register for Social Care 105923</p
A whole earth approach to nature-positive food: biodiversity and agriculture
Agriculture is the largest single source of environmental degradation, responsible for over 30% of global greenhouse gas (GHG) emissions, 70% of freshwater use and 80% of land conversion: it is the single largest driver of biodiversity loss (Foley JA, Science 309:570–574, 2005, Nature 478:337–342, 2011; IPBES. Global assessment report on biodiversity and ecosystem services of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. IPBES Secretariat, Bonn, 2019; Willett W et al. The Lancet 393:447–492, 2019). Agriculture also underpins poor human health, contributing to 11 million premature deaths annually. While too many still struggle from acute hunger, a growing number of individuals, including in low to middle-income countries (LMICs), struggle to access healthy foods. Greater consideration for, and integration of, biodiversity in agriculture is a key solution space for improving health, eliminating hunger and achieving nature-positive development objectives. This rapid evidence review documents the best available evidence of agriculture’s relationships with biodiversity, drawing on the contributions of leading biodiversity experts, and recommends actions that can be taken to move towards more biodiversity/nature-positive production through the delivery of integrated agricultural solutions for climate, biodiversity, nutrition and livelihoods. The analysis, which takes a whole-of-food-system approach, brings together a large body of evidence. It accounts for aspects not typically captured in a stand-alone primary piece of research and indicates where there are critical gaps.Fil: Declerck, Fabrice A.J.. The Alliance of Bioversity International and the International Center for Tropical Agriculture ; FranciaFil: Koziell, Izabella T.. The International Centre for Integrated Mountain Development; NepalFil: Benton, Tim. Chatham House; Reino UnidoFil: Garibaldi, Lucas Alejandro. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Patagonia Norte. Instituto de Investigaciones En Recursos Naturales, Agroecologia y Desarrollo Rural. - Universidad Nacional de Rio Negro. Instituto de Investigaciones En Recursos Naturales, Agroecologia y Desarrollo Rural.; ArgentinaFil: Kremen, Claire. University of British Columbia; CanadáFil: Maron, Martine. University of Queensland; AustraliaFil: Rumbaitis Del Rio, Cristina. World Resources Institute; Estados UnidosFil: Sidhu, Aman. The Alliance of Bioversity International and the International Center for Tropical Agricultura; FranciaFil: Wirths, Jonathan. The Consortium of International Agricultural Research Centers ; Sri LankaFil: Clark, Michael. University of Oxford; Reino UnidoFil: Dickens, Chris. International Water Management Institute; Sri LankaFil: Estrada Carmona, Natalia. The Alliance of Bioversity International and the International Center for Tropical Agriculture ; FranciaFil: Fremier, Alexander K.. Washington State University; Estados UnidosFil: Jones, Sarah K.. The Alliance of Bioversity International and the International Center for Tropical Agriculture ; FranciaFil: Khoury, Colin K.. The Alliance of Bioversity International and the International Center for Tropical Agriculture ; FranciaFil: Lal, Rattan. Ohio State University; Estados UnidosFil: Obersteiner, Michael. University of Oxford; Reino UnidoFil: Remans, Roseline. The Alliance of Bioversity International and the International Center for Tropical Agriculture ; FranciaFil: Rusch, Adrien. Institut National de la Recherche Agronomique; FranciaFil: Schulte, Lisa A.. Natural Resource Ecology and Management; Estados UnidosFil: Simmonds, Jeremy. University of Queensland; AustraliaFil: Stringer, Lindsay C.. University of York; Reino UnidoFil: Weber, Christopher. World Wide Fund For Nature; Estados UnidosFil: Winowiecki, Leigh. World Agroforestry Center; Keni
Interventions targeting social isolation in older people: a systematic review
This is a freely-available open access publication. Please cite the published version which is available via the DOI link in this record.BACKGROUND: Targeting social isolation in older people is a growing public health concern. The proportion of older people in society has increased in recent decades, and it is estimated that approximately 25% of the population will be aged 60 or above within the next 20 to 40 years. Social isolation is prevalent amongst older people and evidence indicates the detrimental effect that it can have on health and wellbeing. The aim of this review was to assess the effectiveness of interventions designed to alleviate social isolation and loneliness in older people. METHODS: Relevant electronic databases (MEDLINE, EMBASE, ASSIA, IBSS, PsycINFO, PubMed, DARE, Social Care Online, the Cochrane Library and CINAHL) were systematically searched using an extensive search strategy, for randomised controlled trials and quasi-experimental studies published in English before May 2009. Additional articles were identified through citation tracking. Studies were included if they related to older people, if the intervention aimed to alleviate social isolation and loneliness, if intervention participants were compared against inactive controls and, if treatment effects were reported. Two independent reviewers extracted data using a standardised form. Narrative synthesis and vote-counting methods were used to summarise and interpret study data. RESULTS: Thirty two studies were included in the review. There was evidence of substantial heterogeneity in the interventions delivered and the overall quality of included studies indicated a medium to high risk of bias. Across the three domains of social, mental and physical health, 79% of group-based interventions and 55% of one-to-one interventions reported at least one improved participant outcome. Over 80% of participatory interventions produced beneficial effects across the same domains, compared with 44% of those categorised as non-participatory. Of interventions categorised as having a theoretical basis, 87% reported beneficial effects across the three domains compared with 59% of interventions with no evident theoretical foundation. Regarding intervention type, 86% of those providing activities and 80% of those providing support resulted in improved participant outcomes, compared with 60% of home visiting and 25% of internet training interventions. Fifty eight percent of interventions that explicitly targeted socially isolated or lonely older people reported positive outcomes, compared with 80% of studies with no explicit targeting. CONCLUSIONS: More, well-conducted studies of the effectiveness of social interventions for alleviating social isolation are needed to improve the evidence base. However, it appeared that common characteristics of effective interventions were those developed within the context of a theoretical basis, and those offering social activity and/or support within a group format. Interventions in which older people are active participants also appeared more likely to be effective. Future interventions incorporating all of these characteristics may therefore be more successful in targeting social isolation in older people.National Institute for Health Researc
JIP1 regulates the directionality of APP axonal transport by coordinating kinesin and dynein motors
Regulation of the opposing kinesin and dynein motors that drive axonal transport is essential to maintain neuronal homeostasis. Here, we examine coordination of motor activity by the scaffolding protein JNK-interacting protein 1 (JIP1), which we find is required for long-range anterograde and retrograde amyloid precursor protein (APP) motility in axons. We identify novel interactions between JIP1 and kinesin heavy chain (KHC) that relieve KHC autoinhibition, activating motor function in single molecule assays. The direct binding of the dynactin subunit p150(Glued) to JIP1 competitively inhibits KHC activation in vitro and disrupts the transport of APP in neurons. Together, these experiments support a model whereby JIP1 coordinates APP transport by switching between anterograde and retrograde motile complexes. We find that mutations in the JNK-dependent phosphorylation site S421 in JIP1 alter both KHC activation in vitro and the directionality of APP transport in neurons. Thus phosphorylation of S421 of JIP1 serves as a molecular switch to regulate the direction of APP transport in neurons
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