456 research outputs found

    A Black Odyssey

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    This book focuses on the career of a single individual—an ambitious, resourceful Black American—and his efforts to realize personal fulfillment in a racist world.No Black American was more determined to realize the promise of American life following the Civil War, nor more frustrated by his inability to do so than John Lewis Waller. Waller, whose first twelve years were spent in slavery, overcame his humble beginnings to become a politician, lawyer, journalist, and diplomat. Nevertheless, his life provides a case study of a middle class black caught between a desire to work within the existing political and economic framework and a need to reject a milieu that was becoming increasingly racist.Waller spent his childhood as a slave in Missouri, and his adolescence on a farm in Iowa. Circumstances and personal ambition combined to allow Waller to acquire a trade—barbering—and a profession—lawyering—in the 1870s. In 1878 he migrated to frontier Kansas, where he practiced law, edited a newspaper, rose to a position of leadership in the black community, and became an important figure in the state Republican party. His political career ended abruptly in 1890, however, when the Republicans rejected his bid to be nominated as the party’s candidate for state auditor. Convinced that his defeat was due to the rising tide of racism throughout the nation, he turned his attentions abroad.Waller was particularly susceptible to the lure of overseas empire because he had spent much of his adult life in the midst of a community of people who had succumbed to the myth of a “promised land,” who were convinced that the Black person would be best able to realize his potential in economically underdeveloped regions not yet exploited and controlled by the white man. In 1891 President Benjamin Harrison appointed Waller United States consul to the east African island of Madagascar. By 1894 Waller had obtained a huge land grant there for the founding of a black utopia. He hoped to establish a plantationcolony that would simultaneously advance his personal fortunes, serve as an investment opportunity for aspiring black capitalists, and constitute a refuge for oppressed AfroAmericans who wished to immigrate. He was thwarted once again by racism, however—this time in the guise of French imperialism. Viewing Waller and his plans as a threat to their hegemony in Madagascar, French authorities quashed the concession, arrested Waller on a charge of being a spy, and sentenced him to twenty years in prison. There followed a fullscale diplomatic confrontation between the United States and France. Waller was released after serving ten months in a French prison, but only after the Cleveland administration agreed to discredit him to the point where he would seem guilty as charged.In his early manhood John Lewis Waller had realized that because he was a Negro personal achievement could not be separated from racial advancement. Responding to that perception, he spent a lifetime searching for a frontier where blacks could enjoy the blessings of democracy and capitalism, and yet be free of the blight of racism. Unlike the vast majority of American Blacks of his time, Waller was able to articulate his dreams, have an impact on the larger, white dominated environment, and realize his individual potential to a remarkable degree. Nevertheless, his dreams were ultimately dashed by racism. His sad but fascinating story deserves the careful attention of all students of politics and race relations during the complex postCivil War year

    Inter and intra-hemispheric structural imaging markers predict depression relapse after electroconvulsive therapy: a multisite study.

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    Relapse of depression following treatment is high. Biomarkers predictive of an individual's relapse risk could provide earlier opportunities for prevention. Since electroconvulsive therapy (ECT) elicits robust and rapidly acting antidepressant effects, but has a >50% relapse rate, ECT presents a valuable model for determining predictors of relapse-risk. Although previous studies have associated ECT-induced changes in brain morphometry with clinical response, longer-term outcomes have not been addressed. Using structural imaging data from 42 ECT-responsive patients obtained prior to and directly following an ECT treatment index series at two independent sites (UCLA: n = 17, age = 45.41±12.34 years; UNM: n = 25; age = 65.00±8.44), here we test relapse prediction within 6-months post-ECT. Random forests were used to predict subsequent relapse using singular and ratios of intra and inter-hemispheric structural imaging measures and clinical variables from pre-, post-, and pre-to-post ECT. Relapse risk was determined as a function of feature variation. Relapse was well-predicted both within site and when cohorts were pooled where top-performing models yielded balanced accuracies of 71-78%. Top predictors included cingulate isthmus asymmetry, pallidal asymmetry, the ratio of the paracentral to precentral cortical thickness and the ratio of lateral occipital to pericalcarine cortical thickness. Pooling cohorts and predicting relapse from post-treatment measures provided the best classification performances. However, classifiers trained on each age-disparate cohort were less informative for prediction in the held-out cohort. Post-treatment structural neuroimaging measures and the ratios of connected regions commonly implicated in depression pathophysiology are informative of relapse risk. Structural imaging measures may have utility for devising more personalized preventative medicine approaches

    Synthetic Ligands of Olfactory Binding Proteins Modulate Aggregation Response of Asian Citrus Psyllid in the Presence of Host-Plant Volatiles

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    There is interest in using ligands of chemosensory binding proteins (CBP) to augment an insect’s responsiveness to chemosensory cues. We showed previously that combining a synthetic ligand of a CBP with limonene, a common citrus volatile, enhanced the probing response of Asian citrus psyllid (Diaphorinacitri). Here, we determined whether synthetic compounds, which were ligands of D. citri olfactory binding protein (OBP) DCSAP4, influenced the settling and aggregation levels of psyllids on young citrus shoots. The test ligands and Cmac scent were dispensed from a droplet of an emulsified wax product (SPLAT) placed on the bottom of each vial. The shoots were presented: (1) alone (shoot + blank SPLAT), (2) with a mixture of citrus volatiles (“Cmac scent”) (shoot + SPLAT with Cmac scent), or (3) with different concentrations of test ligands (shoot + SPLAT with test ligand at concentration 1, shoot + SPLAT with test ligand at concentration 2, etc.). Depending on the availability of test ligands, sprigs, and psyllids, each test included from two to four replicates of each treatment (i.e., shoot only, shoot + Cmac scent, shoot + test ligand at concentration 1, shoot + test ligand at concentration 2, etc.); only a single test ligand was presented in each test. For each test, 200 D. citri were released in the test area and the numbers of psyllids on each sprig were counted 24 h later. Sprigs with ≥7 psyllids were considered to be an aggregation. A total of seven ligands were tested individually. Four of the ligands (654, 717, 784, and 861) modulated psyllid settling and aggregation response, causing greater settling and aggregation to sprigs presented with the Cmac scent than to those sprigs with blank SPLAT. Presentation of one of the ligands (019) resulted in an opposite effect in which psyllid settling and aggregation levels were lower on sprigs with Cmac scent than on those with blank SPLAT. There were no differences in settling levels in the different treatment vials in the Ligand 905 experiment. In the Ligand 937 experiment, settling levels did not vary significantly between treatment vials although settling levels were relatively high in all treatment vials and there was a significant treatment effect. Increased settling and aggregation levels were largely not observed with in the vials with only the test ligands, and there was little effect of ligand concentration on psyllid response levels. This suggests that the test ligands themselves did not attract the psyllids but rather modulated the psyllid’s response to the Cmac scent. The results suggest that synthetic ligands of D. citri CBPs can be used to increase the effectiveness of citrus scent lures used to attract psyllids to monitoring traps and attract and kill devices

    Merging Cold Fronts in the Galaxy Pair NGC 7619 and NGC 7626

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    We present results from {\it Chandra} observations of the galaxy pair NGC 7619 and NGC 7626, the two dominant members of the Pegasus group. The X-ray images show a brightness edge associated with each galaxy, which we identify as merger cold fronts. The edges are sharp, and the axes of symmetry of the edges are roughly anti-parallel, suggesting that these galaxies are falling towards one another in the plane of the sky. The detection of merger cold fronts implies a merging subgroup scenario, since the alternative is that the galaxies are falling into a pre-existing 1\sim1 keV halo without a dominant galaxy of its own, and such objects are not observed. We estimate the 3D velocities from the cold fronts and show that the velocity vectors are indeed most likely close to the plane of the sky, with a relative velocity of \sim1190\kms. The relative velocity is consistent with what is expected from the infall of two roughly equal mass subgroups whose total viral mass equals that of the Pegasus group. We conclude that the Pegasus cluster is currently forming from a major merger of two subgroups, dominated by NGC 7619 and NGC 7626. NGC 7626 contains a strong radio source, a core with two symmetric jets and radio lobes. Although we find no associated structure in the X-ray surface brightness map, the temperature map reveals a clump of cool gas just outside the southern lobe, presumably entrained by the lobe, and an extension of cooler gas into the lobe itself. The jet axis is parallel with the projected direction of motion of NGC 7626 (inferred from the symmetry axis of the merger cold front), and the southern leading jet is foreshortened as compared to the northern trailing one, possibly due to the additional ram pressure the forward jet encounters.Comment: 11 pages, 9 figures. Accepted to ApJ. Minor changes to be consistent with accepted versio

    Solar X-ray Flare Hazards on the Surface of Mars

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    Putative organisms on the Martian surface would be exposed to potentially high doses of ionizing radiation during strong solar X-ray flares. We extrapolate the observed flare frequency-energy release scaling relation to releases much larger than seen so far for the sun, an assumption supported by observations of flares on other solar- and subsolar-mass main sequence stars. We calculate the surficial reprocessed X-ray spectra using a Monte Carlo code we have developed. Biological doses from indirect genome damage are calculated for each parameterized flare spectrum by integration over the X-ray opacity of water. We estimate the mean waiting time for solar flares producing a given biological dose of ionizing radiation on Mars and compare with lethal dose data for a wide range of terrestrial organisms. These timescales range from decades for significant human health risk to 0.5 Myr for D. radiodurans lethality. Such doses require total flare energies of 10^33--10^38 erg, the lower range of which has been observed for other stars. Flares are intermittent bursts, so acute lethality will only occur on the sunward hemisphere during a sufficiently energetic flare, unlike low-dose-rate, extended damage by cosmic rays. We estimate the soil and CO_2 ice columns required to provide 1/e shielding as 4--9 g cm^-2, depending on flare mean energy and atmospheric column density. Topographic altitude variations give a factor of two variation in dose for a given flare. Life in ice layers that may exist ~ 100 g cm^-2 below the surface would be well protected.Comment: To be published in Planetary and Space Science; 33 pages, 3 figure

    From ‘club of the rich’ to ‘globalization à la carte’: evaluating reform at the OECD

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    Recognising the declining weight of its members in the world economy, the OECD, formerly known as a ‘club of rich, industrialised nations’, is undergoing unprecedented organizational reform, including a more inclusive membership logic, engagement with new global players, and outreach to developing countries, all with a view to guaranteeing its continued relevance as a central actor in the task of global policy provision. Using the concepts of global public goods, clubs and models of multilateralism, this article critically evaluates the successes and limits of the OECD’s reform, arguing it is adopting a cautious approach to expansion – globalization ‘ à la carte’. Meaningful reform towards greater inclusion is apparent in the way research on non-members has been mainstreamed, and in its increased work with both emerging powers and developing countries. Limits to reform are found in institutional rigidities including its over-representation of Europe and under-representation of Asia and other continents, reflected through staff profiles and membership. These biases may in turn reduce its attractiveness as a global forum to new players, particularly, China

    International Organizations as Policy Advisors

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    How can international organizations persuade governments to adopt policy recommendations that are based on private information when their interests conflict? We develop a game-theoretic model of persuasion that applies regardless of regime type and does not rely on the existence of domestic constituency constraints+ In the model, an international organization ~IO! and a domestic expert have private information about a crisis, but their preferences diverge from those of the government, which must choose whether to delegate decision making to the expert+ Persuasion can take place if the international institution is able to send a credible signal+ We find that this can take place only if the preferences of the IO and the domestic expert diverge and the institution holds the more moderate policy position+ This result contrasts with conventional wisdom, which holds that the necessary condition for IOs to exert influence is support from a domestic constituency with aligned preferences. Our model suggests that, far from being an obstacle to international cooperation, polarized domestic politics may be a necessary condition for IOs to exert effective influence

    Modeling the whole atmosphere response to solar cycle changes in radiative and geomagnetic forcing

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    The NCAR Whole Atmosphere Community Climate Model, version 3 (WACCM3), is used to study the atmospheric response from the surface to the lower thermosphere to changes in solar and geomagnetic forcing over the 11-year solar cycle. WACCM3 is a general circulation model that incorporates interactive chemistry that solves for both neutral and ion species. Energy inputs include solar radiation and energetic particles, which vary significantly over the solar cycle. This paper presents a comparison of simulations for solar cycle maximum and solar cycle minimum conditions. Changes in composition and dynamical variables are clearly seen in the middle and upper atmosphere, and these in turn affect terms in the energy budget. Generally good agreement is found between the model response and that derived from satellite observations, although significant differences remain. A small but statistically significant response is predicted in tropospheric winds and temperatures which is consistent with signals observed in reanalysis data sets

    White matter microstructural perturbations after total sleep deprivation in depression

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    BackgroundTotal sleep deprivation (TSD) transiently reverses depressive symptoms in a majority of patients with depression. How TSD modulates diffusion tensor imaging (DTI) measures of white matter (WM) microstructure, which may be linked with TSD’s rapid antidepressant effects, remains uncharacterized.MethodsPatients with depression (N = 48, mean age = 33, 26 women) completed diffusion-weighted imaging and Hamilton Depression Rating (HDRS) and rumination scales before and after >24 h of TSD. Healthy controls (HC) (N = 53, 23 women) completed the same assessments at baseline, and after receiving TSD in a subset of HCs (N = 15). Tract based spatial statistics (TBSS) investigated voxelwise changes in fractional anisotropy (FA) across major WM pathways pre-to-post TSD in patients and HCs and between patients and HCs at baseline. Post hoc analyses tested for TSD effects for other diffusion metrics, and the relationships between change in diffusion measures with change in mood and rumination symptoms.ResultsSignificant improvements in mood and rumination occurred in patients with depression (both p < 0.001), but not in HCs following TSD. Patients showed significant (p < 0.05, corrected) decreases in FA values in multiple WM tracts, including the body of the corpus callosum and anterior corona radiata post-TSD. Significant voxel-level changes in FA were not observed in HCs who received TSD (p > 0.05). However, differential effects of TSD between HCs and patients were found in the superior corona radiata, frontal WM and the posterior thalamic radiation (p < 0.05, corrected). A significant (p < 0.05) association between change in FA and axial diffusivity within the right superior corona radiata and improvement in rumination was found post-TSD in patients.ConclusionTotal sleep deprivation leads to rapid microstructural changes in WM pathways in patients with depression that are distinct from WM changes associated with TSD observed in HCs. WM tracts including the superior corona radiata and posterior thalamic radiation could be potential biomarkers of the rapid therapeutic effects of TSD. Changes in superior corona radiata FA, in particular, may relate to improvements in maladaptive rumination
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