Orbital and Suborbital‐Scale Variations of Productivity and Sea Surface Conditions in the Gulf of Alaska During the Past 54,000 Years: Impact of Iron Fertilization by Icebergs and Meltwater

As a high-nutrient and low-chlorophyll region, the modern Gulf of Alaska (GoA) is strongly impacted by the limitation of iron. Paleostudies along the Alaskan slope have mainly focused on reconstructing environmental conditions over the past 18 ka. Based on micropaleontological, biogeochemical, and sedimentological parameters, we explore a sediment record covering the past 54 ka at Integrated Ocean Drilling Program Site U1419 to understand the impact of orbital- and suborbital-scale climate variability on productivity and sea-surface conditions. Close to the Cordilleran Ice Sheet (CIS), Site U1419 is ideally located to elucidate how the evolution of a large ice mass and glacial processes affected orbital- and suborbital-scale changes in nutrients (e.g., iron) supply. Meltwater discharge from the northern CIS impacted sea surface dynamics of GoA coastal waters. The corresponding increases in bulk biogenic concentrations during Marine Isotope Stage (MIS) 3 and MIS 2 (54–17 ka) suggests a direct impact from iron fertilization. The lack of a consistent relationship between productivity and SST suggests that cooling of surface waters was not the dominant control on primary producers. The inundation of the subaerially exposed continental shelf during the last deglacial (17–10 ka) warming could have served as a major micronutrient source, accounting for a deglacial peak in production. Low productivity after the last deglaciation suggests reduced iron availability, which we link to reduced meltwater inputs from smaller ice masses onshore. Our multiproxy approach reveals a more comprehensive picture of late Quaternary productivity variations compared to earlier studies along the Alaskan margin. The impact of tidewater glaciers and meltwater discharge on past marine productivity and nutrient budget dynamics of high-latitude coastal regions is discussed

Warming, euxinia and sea level rise during the Paleocene–Eocene Thermal Maximum on the Gulf Coastal Plain: implications for ocean oxygenation and nutrient cycling

The Paleocene–Eocene Thermal Maximum(PETM, ?56 Ma) was a ?200 kyr episode of globalwarming, associated with massive injections of 13C-depletedcarbon into the ocean–atmosphere system. Although climatechange during the PETM is relatively well constrained,effects on marine oxygen concentrations and nutrientcycling remain largely unclear. We identify the PETM in asediment core from the US margin of the Gulf of Mexico.Biomarker-based paleotemperature proxies (methylationof branched tetraether–cyclization of branched tetraether(MBT–CBT) and TEX86) indicate that continental air andsea surface temperatures warmed from 27–29 to ?35 ?C,although variations in the relative abundances of terrestrialand marine biomarkers may have influenced these estimates.Vegetation changes, as recorded from pollen assemblages,support this warming.The PETM is bracketed by two unconformities. It overliesPaleocene silt- and mudstones and is rich in angular(thus in situ produced; autochthonous) glauconite grains,which indicate sedimentary condensation. A drop in the relativeabundance of terrestrial organic matter and changesin the dinoflagellate cyst assemblages suggest that risingsea level shifted the deposition of terrigenous material landward.This is consistent with previous findings of eustatic sealevel rise during the PETM. Regionally, the attribution of theglauconite-rich unit to the PETM implicates the dating of aprimate fossil, argued to represent the oldest North Americanspecimen on record.The biomarker isorenieratene within the PETM indicatesthat euxinic photic zone conditions developed, likely seasonally,along the Gulf Coastal Plain. A global data compilationindicates that O2 concentrations dropped in allocean basins in response to warming, hydrological change,and carbon cycle feedbacks. This culminated in (seasonal)anoxia along many continental margins, analogous to moderntrends. Seafloor deoxygenation and widespread (seasonal)anoxia likely caused phosphorus regeneration fromsuboxic and anoxic sediments.We argue that this fueled shelfeutrophication, as widely recorded from microfossil studies,increasing organic carbon burial along many continentalPublished by Copernicus Publications on behalf of the European Geosciences Union.Warming, euxinia and sea level rise during the PETMmargins as a negative feedback to carbon input and globalwarming. If properly quantified with future work, the PETMoffers the opportunity to assess the biogeochemical effects ofenhanced phosphorus regeneration, as well as the timescaleson which this feedback operates in view of modern and futureocean deoxygenation

The Hubble Space Telescope Treasury Program on the Orion Nebula Cluster

The Hubble Space Telescope (HST) Treasury Program on the Orion Nebula Cluster has used 104 orbits of HST time to image the Great Orion Nebula region with the Advanced Camera for Surveys (ACS), the Wide-Field/Planetary Camera 2 (WFPC2) and the Near Infrared Camera and Multi Object Spectrograph (NICMOS) instruments in 11 filters ranging from the U-band to the H-band equivalent of HST. The program has been intended to perform the definitive study of the stellar component of the ONC at visible wavelengths, addressing key questions like the cluster IMF, age spread, mass accretion, binarity and cirumstellar disk evolution. The scanning pattern allowed to cover a contiguous field of approximately 600 square arcminutes with both ACS and WFPC2, with a typical exposure time of approximately 11 minutes per ACS filter, corresponding to a point source depth AB(F435W) = 25.8 and AB(F775W)=25.2 with 0.2 magnitudes of photometric error. We describe the observations, data reduction and data products, including images, source catalogs and tools for quick look preview. In particular, we provide ACS photometry for 3399 stars, most of them detected at multiple epochs, WFPC2 photometry for 1643 stars, 1021 of them detected in the U-band, and NICMOS JH photometry for 2116 stars. We summarize the early science results that have been presented in a number of papers. The final set of images and the photometric catalogs are publicly available through the archive as High Level Science Products at the STScI Multimission Archive hosted by the Space Telescope Science Institute.Comment: Accepted for publication on the Astrophysical Journal Supplement Series, March 27, 201

Piecing Together the American Voting Puzzle: How Votersâ Personalities and Judgments of Issue Importance Mattered in the 2016 Presidential Election

In the wake of the 2016 election, which surprised pundits and voters on both the left and the right, there has been renewed interest in understanding what predicts American votersâ choices. In this article, we investigate the roles of personality and issue importance in how people voted in the 2016 U.S. election. In this longitudinal study of 403 MTurk workers who voted in the election, we assessed the relations between personality (openness, social dominance orientation, and national identity importance) and issue importance (group rights and social justice, economic rights, and individual and national rights), and voting for Clinton or Trump. Our results indicate that both individual differences and issue importance as measured in July 2016 predicted votes in November. We also found that the links between personality and voting were mediated by issue importance. Implications for political psychology and the study of personality, campaign issues, and voting behavior are discussed.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146841/1/asap12157.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146841/2/asap12157_am.pd

Personalised service? Changing the role of the government librarian

Investigates the feasibility of personalised information service in a government department. A qualitative methodology explored stakeholder opinions on the remit, marketing, resourcing and measurement of the service. A questionnaire and interviews gathered experiences of personalised provision across the government sector. Potential users were similarly surveyed to discuss how the service could meet their needs. Data were analysed using coding techniques to identify emerging theory. Lessons learned from government librarians centred on clarifying requirements, balancing workloads and selective marketing. The user survey showed low usage and awareness of existing specialist services, but high levels of need and interest in services repackaged as a tailored offering. Fieldwork confirmed findings from the literature on the scope for adding value through information management advice, information skills training and substantive research assistance and the need to understand business processes and develop effective partnerships. Concluding recommendations focus on service definition, strategic marketing, resource utilisation and performance measurement

Warming, euxinia and sea level rise during the Paleocene–Eocene Thermal Maximum on the Gulf Coastal Plain: implications for ocean oxygenation and nutrient cycling

The Paleocene–Eocene Thermal Maximum (PETM, ~ 56 Ma) was a ~ 200 kyr episode of global warming, associated with massive injections of 13C-depleted carbon into the ocean–atmosphere system. Although climate change during the PETM is relatively well constrained, effects on marine oxygen concentrations and nutrient cycling remain largely unclear. We identify the PETM in a sediment core from the US margin of the Gulf of Mexico. Biomarker-based paleotemperature proxies (methylation of branched tetraether–cyclization of branched tetraether (MBT–CBT) and TEX86) indicate that continental air and sea surface temperatures warmed from 27–29 to ~ 35 °C, although variations in the relative abundances of terrestrial and marine biomarkers may have influenced these estimates. Vegetation changes, as recorded from pollen assemblages, support this warming. The PETM is bracketed by two unconformities. It overlies Paleocene silt- and mudstones and is rich in angular (thus in situ produced; autochthonous) glauconite grains, which indicate sedimentary condensation. A drop in the relative abundance of terrestrial organic matter and changes in the dinoflagellate cyst assemblages suggest that rising sea level shifted the deposition of terrigenous material landward. This is consistent with previous findings of eustatic sea level rise during the PETM. Regionally, the attribution of the glauconite-rich unit to the PETM implicates the dating of a primate fossil, argued to represent the oldest North American specimen on record. The biomarker isorenieratene within the PETM indicates that euxinic photic zone conditions developed, likely seasonally, along the Gulf Coastal Plain. A global data compilation indicates that O2 concentrations dropped in all ocean basins in response to warming, hydrological change, and carbon cycle feedbacks. This culminated in (seasonal) anoxia along many continental margins, analogous to modern trends. Seafloor deoxygenation and widespread (seasonal) anoxia likely caused phosphorus regeneration from suboxic and anoxic sediments. We argue that this fueled shelf eutrophication, as widely recorded from microfossil studies, increasing organic carbon burial along many continental margins as a negative feedback to carbon input and global warming. If properly quantified with future work, the PETM offers the opportunity to assess the biogeochemical effects of enhanced phosphorus regeneration, as well as the timescales on which this feedback operates in view of modern and future ocean deoxygenation

R.A.Fisher, design theory, and the Indian connection

Design Theory, a branch of mathematics, was born out of the experimental statistics research of the population geneticist R. A. Fisher and of Indian mathematical statisticians in the 1930s. The field combines elements of combinatorics, finite projective geometries, Latin squares, and a variety of further mathematical structures, brought together in surprising ways. This essay will present these structures and ideas as well as how the field came together, in itself an interesting story.Comment: 11 pages, 3 figure

Gender and sexual orientation differences in cognition across adulthood : age is kinder to women than to men regardless of sexual orientation

Despite some evidence of greater age-related deterioration of the brain in males than in females, gender differences in rates of cognitive aging have proved inconsistent. The present study employed web-based methodology to collect data from people aged 20-65 years (109,612 men; 88,509 women). As expected, men outperformed women on tests of mental rotation and line angle judgment, whereas women outperformed men on tests of category fluency and object location memory. Performance on all tests declined with age but significantly more so for men than for women. Heterosexuals of each gender generally outperformed bisexuals and homosexuals on tests where that gender was superior; however, there were no clear interactions between age and sexual orientation for either gender. At least for these particular tests from young adulthood to retirement, age is kinder to women than to men, but treats heterosexuals, bisexuals, and homosexuals just the same

On the Black-Hole/Qubit Correspondence

The entanglement classification of four qubits is related to the extremal black holes of the 4-dimensional STU model via a time-like reduction to three dimensions. This correspondence is generalised to the entanglement classification of a very special four-way entanglement of eight qubits and the black holes of the maximally supersymmetric N = 8 and exceptional magic N = 2 supergravity theories.Comment: 32 pages, very minor changes at the start of Sec. 4.1. Version to appear in The European Physical Journal - Plu