Resolution of conflict between parental genomes in a hybrid species

AbstractThe development of reproductive barriers against parent species is crucial during hybrid speciation, and post-zygotic isolation can be important in this process. Genetic incompatibilities that normally isolate the parent species can become sorted in hybrids to form reproductive barriers towards either parent. However, the extent to which this sorting process is systematically biased and therefore predictable in which loci are involved and which alleles are favored is largely unknown. Theoretically, reduced fitness in hybrids due to the mixing of differentiated genomes can be resolved through rapid evolution towards allelic combinations ancestral to lineage-splitting of the parent species, as these alleles have successfully coexisted in the past. However, for each locus, this effect may be influenced by its chromosomal location, function, and interactions with other loci. We use the Italian sparrow, a homoploid hybrid species that has developed post-zygotic barriers against its parent species, to investigate this prediction. We show significant bias towards fixation of the ancestral allele among 57 nuclear intragenic SNPs, particularly those with a mitochondrial function whose ancestral allele came from the same parent species as the mitochondria. Consistent with increased pleiotropy leading to stronger fitness effects, genes with more protein-protein interactions were more biased in favor of the ancestral allele. Furthermore, the number of protein-protein interactions was especially low among candidate incompatibilities still segregating within Italian sparrows, suggesting that low pleiotropy allows steep intraspecific clines in allele frequencies to form. Finally, we report evidence for pervasive epistatic interactions within one Italian sparrow population, particularly involving loci isolating the two parent species but not hybrid and parent. However there was a lack of classic incompatibilities and no admixture linkage disequilibrium. This suggests that parental genome admixture can continue to constrain evolution and prevent genome stabilization long after incompatibilities have been purged.</jats:p

Ups and Downs in Finance, Ups without Downs in Inequality

The upswing in finance over the past several decades has led to rising inequality, but do downswings in finance lead to a symmetric decline in inequality? In this paper, we analyze the asymmetry of the effect of ups and downs in financial markets, as well as the effect of increased capital requirements and the bonus cap on national earnings in- equality. We use administrative employer–employee linked data on earnings from 1990 to 2017 for twelve countries. Additionally, we use data on earnings from bank reports, from 2009 to 2017 in thirteen European countries. We find a strong asymmetry in the effects of financial ups and downs on earnings inequality, a mitigating effect of rising capital requirements on the contribution of finance to inequality, and a restructuring ef- fect of the bonus cap for the earnings of financiers, while neither policy affects absolute levels of earnings inequality.La hausse de la finance au cours des dernières décennies a entraîné une hausse des inégalités, mais les ralentissements de la finance entraînent-ils une baisse symétrique des inégalités? Dans cet article, nous examinons l'asymétrie de l'effet des hausses et des ralentissements des marchés financiers, ainsi que l'effet de l'augmentation des exi- gences en matière de capital et du plafonnement des primes sur l'inégalité des salaires nationaux. Nous utilisons des données administratives couplées employeur-employé sur les salaires de 1990 à 2017 pour douze pays. De plus, nous employons des données sur les salaires provenant des rapports bancaires, de 2009 à 2017, dans 13 pays euro- péens. Nous constatons une forte asymétrie dans les effets des hausses et des ralentis- sements financières sur l'inégalité des salaires, un effet de mitigation de l'augmentation des exigences de capitalisation sur la contribution de la finance à l'inégalité, et un effet de restructuration du plafonnement des primes pour les salaires des financiers, alors qu'aucune des deux mesures n'affecte les niveaux absolus d'inégalité des salaires.iv MaxPo Discussion Paper 21/2 1 Introduction 2 Data Administrative employer–employee linked data World Bank GFDD database European bank reports 3 The contribution of financiers’ earnings to inequality and its asymmetry in upswings and downswings Less finance, less inequality? The asymmetry of the redistribution of earnings through financialization 4 Finance, regulation, and inequality Capital requirements and inequality The bonus cap 5 Conclusion Appendices A1 Data description A2 Supplementary tables and figures Reference

Constraints on oceanic methane emissions west of Svalbard from atmospheric in situ measurements and Lagrangian transport modeling

Methane stored in seabed reservoirs such as methane hydrates can reach the atmosphere in the form of bubbles or dissolved in water. Hydrates could destabilize with rising temperature further increasing greenhouse gas emissions in a warming climate. To assess the impact of oceanic emissions from the area west of Svalbard, where methane hydrates are abundant, we used measurements collected with a research aircraft (Facility for Airborne Atmospheric Measurements) and a ship (Helmer Hansen) during the Summer 2014 and for Zeppelin Observatory for the full year. We present a model-supported analysis of the atmospheric CH$_{4}$mixing ratios measured by the different platforms. To address uncertainty about where CH$_{4}$ emissions actually occur, we explored three scenarios: areas with known seeps, a hydrate stability model, and an ocean depth criterion. We then used a budget analysis and a Lagrangian particle dispersion model to compare measurements taken upwind and downwind of the potential CH$_{4}$ emission areas. We found small differences between the CH$_{4}$ mixing ratios measured upwind and downwind of the potential emission areas during the campaign. By taking into account measurement and sampling uncertainties and by determining the sensitivity of the measured mixing ratios to potential oceanic emissions, we provide upper limits for the CH$_{4}$ fluxes. The CH$_{4}$ flux during the campaign was small, with an upper limit of 2.5 nmol m$^{-2}$ s$^{-1}$ in the stability model scenario. The Zeppelin Observatory data for 2014 suggest CH$_{4}$ fluxes from the Svalbard continental platform below 0.2 Tg yr$^{-1}$. All estimates are in the lower range of values previously reported.MOCA—Methane Emissions from the Arctic OCean to the Atmosphere: Present and Future Climate Effects is funded by the Research Council of Norway, grant 225814. CAGE—Centre for Arctic Gas Hydrate, Environment and Climate research work was supported by the Research Council of Norway through its Centres of Excellence funding scheme grant 223259. eSTICC—eScience Tools for Investigating Climate Change in northern high latitudes is supported by Nordforsk as Nordic Center of Excellence grant 57001. NERC grants NE/I029293/1 (PI. H. Coe) and NE/I02916/1 (PI J. Pyle) and Methane & Other Greenhouse Gases in the Arctic—Measurements, Process Studies and Modelling (MAMM). The ERC through the ACCI project, project number 267760. The biogenic methane emission data from the LPX-Bern v1.2 model were provided by Renato Spahni. The methane emission data from the GAINS model were provided by IIASA. GFED data are available from http://www.globalfiredata.org/index.html. Airborne data were obtained using the BAe-146-301 Atmospheric Research Aircraft (ARA) flown by Directflight Ltd. and managed by the Facility for Airborne Atmospheric Measurements (FAAM), which is a joint entity of the Natural Environment Research Council (NERC) and the Met Office. Zeppelin and Helmer Hansen atmospheric measurement data are archived in EBAS (http://ebas.nilu.no/) for long-term preservation, access and use. All Zeppelin data for 2014: http://ebas.nilu.no/DataSets.aspx?stations=NO0042G&fromDate=2014-01-01&toDate=2014-12-31. All atmospheric data from RV Helmer Hanssen: http://ebas.nilu.no/DataSets.aspx?stations=NO1000R&fromDate=2014-01-01&toDate=2014-12-31 (password is required until the end of 2017)

The Great Separation: Top Earner Segregation at Work in High-Income Countries

Analyzing linked employer-employee panel administrative databases, we study the evolving isolation of higher earners from other employees in eleven countries: Canada, Czechia, Denmark, France, Germany, Hungary, Japan, Norway, Spain, South Korea, and Sweden. We find in almost all countries a growing workplace isolation of top earners and dramatically declining exposure of top earners to bottom earners. We compare these trends to segregation based on occupational class, education, age, gender, and nativity, finding that the rise in top earner isolation is much more dramatic and general across countries. We find that residential segregation is also growing, although more slowly than segregation at work, with top earners and bottom earners increasingly living in different distinct municipalities. While work and residential segregation are correlated, statistical modeling suggests that the primary causal effect is from work to residential segregation. These findings open up a future research program on the causes and consequences of top earner segregation.En nous appuyant sur des données administratives longitudinales employeur–employés, nous analysons l’évolution de la ségrégation sociale des salariés à hauts salaires dans onze pays: Allemagne, Canada, Corée du Sud, Danemark, Espagne, France, Hongrie, Japon, Norvège, République tchèque et Suède. Nous constatons dans presque tous les pays une forte augmentation de l’entre soi des salariés bien payés sur le lieu de travail et une diminution spectaculaire de leur exposition aux bas salaires. Nous comparons ces tendances à l’évolution de la ségrégation fondée sur la catégorie sociale, l’éducation, l’âge, le sexe et le statut migratoire, et nous constatons que l’augmentation de l’entre soi des hauts salaires est celle qui est la plus prononcée et la plus générale. Nous montrons que la ségrégation résidentielle se développe aussi, bien que plus lentement que la ségrégation au travail, avec les hauts et les bas salaires vivant de plus en plus dans des municipalités distinctes. Ségrégation au travail et ségrégation résidentielle sont corrélées. Mais nos modèles statistiques suggèrent aussi que la principale relation de causalité va de la ségrégation au travail vers la ségrégation résidentielle. Ces résultats ouvrent la voie à un futur programme de recherche sur les causes et les conséquences de la ségrégation des hauts salaires.1 Introduction 2 From ethnic residential segregation to earnings segregation at work 3 Administrative data for estimating exposure measures 4 A strong increase in earnings segregation at work 5 A robust trend 17 French robustness tests 6 A specific trend 7 The link between work and residential segregation 8 Elements for a research program on the causes and consequences of increasing segregation at work The roots of growing earnings segregation at work The consequences of growing earnings segregation at work Appendices A1 Data sources and sample definition A2 Demonstration of the symmetry of relative exposure gRh = hRg A3 Figure construction A4 French robustness checks Supplementary figures and tables Reference

Very Strong Atmospheric Methane Growth in the 4 Years 2014–2017:Implications for the Paris Agreement

Atmospheric methane grew very rapidly in 2014 (12.7 ± 0.5 ppb/year), 2015 (10.1 ± 0.7 ppb/year), 2016 (7.0 ± 0.7 ppb/year), and 2017 (7.7 ± 0.7 ppb/year), at rates not observed since the 1980s. The increase in the methane burden began in 2007, with the mean global mole fraction in remote surface background air rising from about 1,775 ppb in 2006 to 1,850 ppb in 2017. Simultaneously the 13 C/ 12 C isotopic ratio (expressed as δ 13 C CH4 ) has shifted, has shifted, now trending negative for more than a decade. The causes of methane's recent mole fraction increase are therefore either a change in the relative proportions (and totals) of emissions from biogenic and thermogenic and pyrogenic sources, especially in the tropics and subtropics, or a decline in the atmospheric sink of methane, or both. Unfortunately, with limited measurement data sets, it is not currently possible to be more definitive. The climate warming impact of the observed methane increase over the past decade, if continued at >5 ppb/year in the coming decades, is sufficient to challenge the Paris Agreement, which requires sharp cuts in the atmospheric methane burden. However, anthropogenic methane emissions are relatively very large and thus offer attractive targets for rapid reduction, which are essential if the Paris Agreement aims are to be attained

Evidence for Mito-Nuclear and Sex-Linked Reproductive Barriers between the Hybrid Italian Sparrow and Its Parent Species

Studies of reproductive isolation between homoploid hybrid species and their parent species have rarely been carried out. Here we investigate reproductive barriers between a recently recognized hybrid bird species, the Italian sparrow Passer italiae and its parent species, the house sparrow P. domesticus and Spanish sparrow P. hispaniolensis. Reproductive barriers can be difficult to study in hybrid species due to lack of geographical contact between taxa. However, the Italian sparrow lives parapatrically with the house sparrow and both sympatrically and parapatrically with the Spanish sparrow. Through whole-transcriptome sequencing of six individuals of each of the two parent species we identified a set of putatively parent species-diagnostic single nucleotide polymorphism (SNP) markers. After filtering for coverage, genotyping success (>97%) and multiple SNPs per gene, we retained 86 species-informative, genic, nuclear and mitochondrial SNP markers from 84 genes for analysis of 612 male individuals. We show that a disproportionately large number of sex-linked genes, as well as the mitochondria and nuclear genes with mitochondrial function, exhibit sharp clines at the boundaries between the hybrid and the parent species, suggesting a role for mito-nuclear and sex-linked incompatibilities in forming reproductive barriers. We suggest that genomic conflict via interactions between mitochondria and sex-linked genes with mitochondrial function ("mother's curse") at one boundary and centromeric drive at the other may best explain our findings. Hybrid speciation in the Italian sparrow may therefore be influenced by mechanisms similar to those involved in non-hybrid speciation, but with the formation of two geographically separated species boundaries instead of one. Spanish sparrow alleles at some loci have spread north to form reproductive barriers with house sparrows, while house sparrow alleles at different loci, including some on the same chromosome, have spread in the opposite direction to form barriers against Spanish sparrows

Inverse modelling of European CH4 emissions during 2006-2012 using different inverse models and reassessed atmospheric observations

We present inverse modelling (top down) estimates of European methane (CH4) emissions for 2006-2012 based on a new quality-controlled and harmonised in situ data set from 18 European atmospheric monitoring stations. We applied an ensemble of seven inverse models and performed four inversion experiments, investigating the impact of different sets of stations and the use of a priori information on emissions.The inverse models infer total CH4 emissions of 26.8 (20.2-29.7) TgCH(4) yr(-1) (mean, 10th and 90th percentiles from all inversions) for the EU-28 for 2006-2012 from the four inversion experiments. For comparison, total anthropogenic CH4 emissions reported to UNFCCC (bottom up, based on statistical data and emissions factors) amount to only 21.3 TgCH(4) yr(-1) (2006) to 18.8 TgCH(4) yr(-1) (2012). A potential explanation for the higher range of top-down estimates compared to bottom-up inventories could be the contribution from natural sources, such as peatlands, wetlands, and wet soils. Based on seven different wetland inventories from the Wetland and Wetland CH4 Inter-comparison of Models Project (WETCHIMP), total wetland emissions of 4.3 (2.3-8.2) TgCH(4) yr(-1) from the EU-28 are estimated. The hypothesis of significant natural emissions is supported by the finding that several inverse models yield significant seasonal cycles of derived CH4 emissions with maxima in summer, while anthropogenic CH4 emissions are assumed to have much lower seasonal variability. Taking into account the wetland emissions from the WETCHIMP ensemble, the top-down estimates are broadly consistent with the sum of anthropogenic and natural bottom-up inventories. However, the contribution of natural sources and their regional distribution remain rather uncertain.Furthermore, we investigate potential biases in the inverse models by comparison with regular aircraft profiles at four European sites and with vertical profiles obtained during the Infrastructure for Measurement of the European Carbon Cycle (IMECC) aircraft campaign. We present a novel approach to estimate the biases in the derived emissions, based on the comparison of simulated and measured enhancements of CH4 compared to the background, integrated over the entire boundary layer and over the lower troposphere. The estimated average regional biases range between -40 and 20% at the aircraft profile sites in France, Hungary and Poland.</p

Extensive release of methane from Arctic seabed west of Svalbard during summer 2014 does not influence the atmosphere

© 2016. American Geophysical Union. All Rights Reserved. We find that summer methane (CH4) release from seabed sediments west of Svalbard substantially increases CH4 concentrations in the ocean but has limited influence on the atmospheric CH4 levels. Our conclusion stems from complementary measurements at the seafloor, in the ocean, and in the atmosphere from land-based, ship and aircraft platforms during a summer campaign in 2014. We detected high concentrations of dissolved CH4 in the ocean above the seafloor with a sharp decrease above the pycnocline. Model approaches taking potential CH4 emissions from both dissolved and bubble-released CH4 from a larger region into account reveal a maximum flux compatible with the observed atmospheric CH4 mixing ratios of 2.4-3.8 nmol m-2 s-1. This is too low to have an impact on the atmospheric summer CH4 budget in the year 2014. Long-term ocean observatories may shed light on the complex variations of Arctic CH4 cycles throughout the year.The project MOCA- Methane Emissions from the Arctic OCean to the Atmosphere: Present and Future Climate Effects is funded by the Research Council of Norway, grant no.225814 CAGE – Centre for Arctic Gas Hydrate, Environment and Climate research work was supported by the Research Council of Norway through its Centres of Excellence funding scheme grant no. 223259. Nordic Center of Excellence eSTICC (eScience Tool for Investigating Climate Change in northern high latitudes) funded by Nordforsk, grant no. 57001

Effects of Insulin Detemir and NPH Insulin on Body Weight and Appetite-Regulating Brain Regions in Human Type 1 Diabetes: A Randomized Controlled Trial

Studies in rodents have demonstrated that insulin in the central nervous system induces satiety. In humans, these effects are less well established. Insulin detemir is a basal insulin analog that causes less weight gain than other basal insulin formulations, including the current standard intermediate-long acting Neutral Protamine Hagedorn (NPH) insulin. Due to its structural modifications, which render the molecule more lipophilic, it was proposed that insulin detemir enters the brain more readily than other insulins. The aim of this study was to investigate whether insulin detemir treatment differentially modifies brain activation in response to food stimuli as compared to NPH insulin. In addition, cerebral spinal fluid (CSF) insulin levels were measured after both treatments. Brain responses to viewing food and non-food pictures were measured using functional Magnetic Resonance Imaging in 32 type 1 diabetic patients, after each of two 12-week treatment periods with insulin detemir and NPH insulin, respectively, both combined with prandial insulin aspart. CSF insulin levels were determined in a subgroup. Insulin detemir decreased body weight by 0.8 kg and NPH insulin increased weight by 0.5 kg (p = 0.02 for difference), while both treatments resulted in similar glycemic control. After treatment with insulin detemir, as compared to NPH insulin, brain activation was significantly lower in bilateral insula in response to visual food stimuli, compared to NPH (p = 0.02 for right and p = 0.05 for left insula). Also, CSF insulin levels were higher compared to those with NPH insulin treatment (p = 0.003). Our findings support the hypothesis that in type 1 diabetic patients, the weight sparing effect of insulin detemir may be mediated by its enhanced action on the central nervous system, resulting in blunted activation in bilateral insula, an appetite-regulating brain region, in response to food stimuli.ClinicalTrials.gov NCT00626080