386 research outputs found

    Racism and racial categorization.

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    Social identity theory predicts that perceivers strongly identified with an in-group will maximize the distinction and maintain a clear boundary between their own and other groups by categorizing others' membership accurately. Two experiments tested the prediction that racially prejudiced individuals, who presumably identify highly with their racial in-group, are more motivated to make accurate racial categorizations than nonprejudiced individuals. Results indicated that prejudiced participants not only took longer to categorize race-ambiguous targets (Experiments 1 and 2), but also made more nonverbal vocalizations when presented with them (Experiment 1), suggesting response hesitation. The results support the hypothesis that, compared to nonprejudiced individuals, prejudiced individuals concern themselves with accurate identification of in-group and out-group members and use caution when making racial categorizations

    Phenomenological High Precision Neutron-Proton Delta-Shell Potential

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    We provide a successful fit for proton-neutron scattering below pion production threshold up to LAB energies of 350 MeV. We use seven high-quality fits based on potentials with different forms as a measure of the systematic uncertainty. We represent the interaction as a sum of delta-shells in configuration space below the 3fm and a charge dependent one pion exchange potential above 3fm together with magnetic and vacuum polarization effects. Special attention is paid to estimate the errors of the phenomenological interaction.Comment: 5 pages, 2 figures. Comments and one figure with differential observables adde

    Coumarin-Annulated Ferrocenyl 1,3-Oxazine Derivatives Possessing In Vitro Antimalarial and Antitrypanosomal Potency

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    A tailored series of coumarin-based ferrocenyl 1,3-oxazine hybrid compounds was synthesized and investigated for potential antiparasitic activity, drawing inspiration from the established biological efficacy of the constituent chemical motifs. The structural identity of the synthesized compounds was confirmed by common spectroscopic techniques: NMR, HRMS and IR. Biological evaluation studies reveal that the compounds exhibit higher in vitro antiparasitic potency against the chemosensitive malarial strain (3D7 P. falciparum) over the investigated trypanosomiasis causal agent (T. b. brucei 427) with mostly single digit micromolar IC50 values. When read in tandem with the biological performance of previously reported structurally similar non-coumarin, phenyl derivatives (i.e., ferrocenyl 1,3-benzoxazines and α-aminocresols), structure-activity relationship analyses suggest that the presence of the coumarin nucleus is tolerated for biological activity though this may lead to reduced efficacy. Preliminary mechanistic studies with the most promising compound (11b) support hemozoin inhibition and DNA interaction as likely mechanistic modalities by which this class of compounds may act to produce plasmocidal and antitrypanosomal effects

    Ship-based contributions to global ocean, weather, and climate observing systems

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    The role ships play in atmospheric, oceanic, and biogeochemical observations is described with a focus on measurements made within 100 m of the ocean surface. Ships include merchant and research vessels, cruise liners and ferries, fishing vessels, coast guard, military, and other government-operated ships, yachts, and a growing fleet of automated surface vessels. The present capabilities of ships to measure essential climate/ocean variables and the requirements from a broad community to address operational, commercial, and scientific needs are described. Following the guidance from the OceanObs'19 organizing committee, the authors provide a vision to expand observations needed from ships to understand and forecast the exchanges across the ocean-atmosphere interface. The vision addresses (1) recruiting vessels to improve both spatial and temporal sampling, (2) conducting multi-variate sampling on ships, (3) raising technology readiness levels of automated shipboard sensors and ship-to-shore data communications, (4) advancing quality evaluation of observations, and (5) developing a unified data management approach for observations and metadata that meets the needs of a diverse user community. Recommendations are made focusing on integrating private and autonomous vessels into the observing system, investing in sensor and communications technology development, developing an integrated data management structure that includes all types of ships, and moving towards a quality evaluation process that will result in a subset of ships being defined as mobile reference ships that will support climate studies. We envision a future where commercial, research, and privately-owned vessels are making multivariate observations using a combination of automated and human-observed measurements. All data and metadata will be documented, tracked, evaluated, distributed, and archived to benefit users of marine data. This vision looks at ships as a holistic network, not a set of disparate commercial, research, and/or third-party activities working in isolation, to bring these communities together for the mutual benefit of all

    Long-term evolution of upper stratospheric ozone at selected stations of the Network for the Detection of Stratospheric Change (NDSC)

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    The long-term evolution of upper stratospheric ozone has been recorded by lidars and microwave radiometers within the ground-based Network for the Detection of Stratospheric Change (NDSC), and by the space-borne Solar Backscatter Ultra-Violet instruments (SBUV), Stratospheric Aerosol and Gas Experiment (SAGE), and Halogen Occultation Experiment (HALOE). Climatological mean differences between these instruments are typically smaller than 5% between 25 and 50 km. Ozone anomaly time series from all instruments, averaged from 35 to 45 km altitude, track each other very well and typically agree within 3 to 5%. SBUV seems to have a slight positive drift against the other instruments. The corresponding 1979 to 1999 period from a transient simulation by the fully coupled MAECHAM4-CHEM chemistry climate model reproduces many features of the observed anomalies. However, in the upper stratosphere the model shows too low ozone values and too negative ozone trends, probably due to an underestimation of methane and a consequent overestimation of ClO. The combination of all observational data sets provides a very consistent picture, with a long-term stability of 2% or better. Upper stratospheric ozone shows three main features: (1) a decline by 10 to 15% since 1980, due to chemical destruction by chlorine; (2) two to three year fluctuations by 5 to 10%, due to the Quasi-Biennial Oscillation (QBO); (3) an 11-year oscillation by about 5%, due to the 11-year solar cycle. The 1979 to 1997 ozone trends are larger at the southern mid-latitude station Lauder (45 S), reaching 8%/decade, compared to only about 6%/decade at Table Mountain (35 N), Haute Provence/Bordeaux ( 45 N), and Hohenpeissenberg/Bern( 47 N). At Lauder, Hawaii (20 N), Table Mountain, and Haute Provence, ozone residuals after subtraction of QBO- and solar cycle effects have levelled off in recent years, or are even increasing. Assuming a turning point in January 1997, the change of trend is largest at southern mid-latitude Lauder, +11%/decade, compared to +7%/decade at northern mid-latitudes. This points to a beginning recovery of upper stratospheric ozone. However, chlorine levels are still very high and ozone will remain vulnerable. At this point the most northerly mid-latitude station, Hohenpeissenberg/Bern differs from the other stations, and shows much less clear evidence for a beginning recovery, with a change of trend in 1997 by only +3%/decade. In fact, record low upper stratospheric ozone values were observed at Hohenpeissenberg/Bern, and to a lesser degree at Table Mountain and Haute Provence, in the winters 2003/2004 and 2004/2005

    Does intergroup contact predict personality? A longitudinal study on the bidirectional relationship between intergroup contact and personality traits

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    We conducted a longitudinal study to test whether, in addition to being predicted by personality, intergroup contact is longitudinally associated with personality traits. Participants were 388 majority (Italian) and 109 minority (immigrant) first-year highschool students. Results revealed a bidirectional relationship between contact and personality: quality of contact was longitudinally associated with greater agreeableness and openness to experience, while agreeableness and openness to experience were longitudinal predictors of contact quality. An unexpected negative longitudinal association also emerged between quantity of contact and agreeableness. These effects were not moderated by group of belonging (majority vs. minority). Our findings highlight the importance of integrating research on intergroup contact with research on personality

    Sildenafil attenuates pulmonary arterial pressure but does not improve oxygenation during ARDS

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    OBJECTIVE: Pulmonary hypertension is a characteristic feature of acute respiratory distress syndrome (ARDS) and contributes to mortality. Administration of sildenafil in ambulatory patients with pulmonary hypertension improves oxygenation and ameliorates pulmonary hypertension. Our aim was to determine whether sildenafil is beneficial for patients with ARDS. DESIGN: Prospective, open-label, multicenter, interventional cohort study. SETTING: Medical-surgical ICU of two university hospitals. PATIENTS: Ten consecutive patients meeting the NAECC criteria for ARDS. INTERVENTIONS: A single dose of 50 mg sildenafil citrate administered via a nasogastric tube. MAIN RESULTS: Administration of sildenafil in patients with ARDS decreased mean pulmonary arterial pressure from 25 to 22 mmHg (P = 0.022) and pulmonary artery occlusion pressure from 16 to 13 mmHg (P = 0.049). Systemic mean arterial pressures were markedly decreased from 81 to 75 mmHg (P = 0.005). Sildenafil did not improve pulmonary arterial oxygen tension, but resulted in a further increase in the shunt fraction. CONCLUSION: Although sildenafil reduced pulmonary arterial pressures during ARDS, the increased shunt fraction and decreased arterial oxygenation render it unsuitable for the treatment of patients with ARD

    Diverse animal models to examine potential role(s) and mechanism of endocrine disrupting chemicals on the tumor progression and prevention: Do they have tumorigenic or anti-tumorigenic property?

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    Acting as hormone mimics or antagonists in the interaction with hormone receptors, endocrine disrupting chemicals (EDCs) have the potentials of disturbing the endocrine system in sex steroid hormone-controlled organs and tissues. These effects may lead to the disruption of major regulatory mechanisms, the onset of developmental disorders, and carcinogenesis. Especially, among diverse EDCs, xenoestrogens such as bisphenol A, dioxins, and di(2-ethylhexyl)phthalate, have been shown to activate estrogen receptors (ERs) and to modulate cellular functions induced by ERs. Furthermore, they appear to be closely related with carcinogenicity in estrogen-dependant cancers, including breast, ovary, and prostate cancers. In in vivo animal models, prenatal exposure to xenoestrogens changed the development of the mouse reproductive organs and increased the susceptibility to further carcinogenic exposure and tumor occurence in adults. Unlike EDCs, which are chemically synthesized, several phytoestrogens such as genistein and resveratrol showed chemopreventive effects on specific cancers by contending with ER binding and regulating normal ER action in target tissues of mice. These results support the notion that a diet containing high levels of phytoestrogens can have protective effects on estrogen-related diseases. In spite of the diverse evidences of EDCs and phytoestrogens on causation and prevention of estrogen-dependant cancers provided in this article, there are still disputable questions about the dose-response effect of EDCs or chemopreventive potentials of phytoestrogens. As a wide range of EDCs including phytoestrogens have been remarkably increasing in the environment with the rapid growth in our industrial society and more closely affecting human and wildlife, the potential risks of EDCs in endocrine disruption and carcinogenesis are important issues and needed to be verified in detail

    Constraining calcium isotope fractionation (δ44/40Ca) in modern and fossil scleractinian coral skeleton

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    The present study investigates the influence of environmental (temperature, salinity) and biological (growth rate, inter-generic variations) parameters on calcium isotope fractionation (δ44/40Ca) in scleractinian coral skeleton to better constrain this record. Previous studies focused on the δ44/40Ca record in different marine organisms to reconstruct seawater composition or temperature, but only few studies investigated corals. This study presents measurements performed on modern corals from natural environments (from the Maldives for modern and from Tahiti for fossil corals) as well as from laboratory cultures (Centre Scientifique de Monaco). Measurements on Porites sp., Acropora sp., Montipora verrucosa and Stylophora pistillata allow constraining inter-generic variability. Our results show that the fractionation of δ44/40Ca ranges from 0.6 to 0.1‰, independent of the genus or the environmental conditions. No significant relationship between the rate of calcification and δ44/40Ca was found. The weak temperature dependence reported in earlier studies is most probably not the only parameter that is responsible for the fractionation. Indeed, sub-seasonal temperature variations reconstructed by δ18O and Sr/Ca ratio using a multi-proxy approach, are not mirrored in the coral's δ44/40Ca variations. The intergeneric variability and intrageneric variability among the studied samples are weak except for S. pistillata, which shows calcium isotopic values increasing with salinity. The variability between samples cultured at a salinity of 40 is higher than those cultured at a salinity of 36 for this species. The present study reveals a strong biological control of the skeletal calcium isotope composition by the polyp and a weak influence of environmental factors, specifically temperature and salinity (except for S. pistillata). Vital effects have to be investigated in situ to better constrain their influence on the calcium isotopic signal. If vital effects could be extracted from the isotopic signal, the calcium isotopic composition of coral skeletons could provide reliable information on the calcium composition and budget in ocean. Highlights ► Corals cultured in aquaria or from natural environment show the same Ca isotopic composition. ► δ44/40Ca of coral skeleton is independent of depositional setting environment. ► Strong influence of vital effects on coral skeleton δ44/40Ca composition and calcification mechanism

    Emissions scenarios: A final response

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    This note is a final response to the debate raised by Mr. Castles and Mr. Henderson (for brevity, we refer here to the two authors simply as C&H) in this Journal (vol 14, no 2&3, and no 4) on the issue of economic growth in developing countries in some of the emissions scenarios published in the IPCC Special Report on Emissions Scenarios (SRES) (Nakicenovic et al., 2000). We first outline areas of agreement and then the remaining areas of disagreement. Two important areas of agreement have emerged from the debate according to our view. First, both parties agree that scenarios assuming a conditional convergence in income levels, i.e., a higher growth in per capita income in poorer countries when compared to countries with higher levels of affluence, are both "plausible and well attested in economic history" (C&H, p. 424). Thus, the fundamental, structural characteristic of some of the SRES scenarios contested by C&H are not challenged per se, but rather how fast such trends could unfold in the future
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