506 research outputs found

    Stop stereotyping.

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    Restraining the expression of stereotypes is a necessary requirement for harmonious living, yet surprisingly little is known about the efficacy of this process. Accordingly, in two experiments, here we used a stop-signal task to establish how effectively stereotype-related responses can be inhibited. In Experiment 1, following the presentation of gender-typed occupational contexts, participants reported the sex of target faces (i.e., Go trials) unless an occasional auditory tone indicated they should withhold their response (i.e., Stop trials). In Experiment 2, following the presentation of male and female faces, participants made either stereotypic or counter-stereotypic judgments, unless a stop signal was presented. Regardless of whether stereotyping was probed indirectly (Experiment 1) or directly (Experiment 2), a consistent pattern of results was observed; inhibition was faster for stereotypic compared with counter-stereotypic responses. These findings demonstrate that stopping stereotyping may be less challenging than has widely been assumed

    Stereotype-based priming without stereotype activation: A tale of two priming tasks

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    An extensive literature has demonstrated stereotype-based priming effects. What this work has only recently considered, however, is the extent to which priming is moderated by the adoption of different sequential-priming tasks and the attendant implications for theoretical treatments of person perception. In addition, the processes through which priming arises (i.e., stimulus and/or response biases) remain largely unspecified. Accordingly, here we explored the emergence and origin of stereotype-based priming using both semantic- and response-priming tasks. Corroborating previous research, a stereotype-based priming effect only emerged when a response-priming (vs. semantic-priming) task was used. A further hierarchical drift diffusion model analysis revealed that this effect was underpinned by differences in the evidential requirements of response generation (i.e., a response bias), such that less evidence was needed when generating stereotype-consistent compared with stereotype-inconsistent responses. Crucially, information uptake (i.e., stimulus bias, efficiency of target processing) was faster for stereotype-inconsistent than stereotype-consistent targets. This reveals that stereotype-based priming originated in a response bias rather than the automatic activation of stereotypes. The theoretical implications of these findings are considered. </jats:p

    How prioritized is self-prioritization during stimulus processing?

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    Recent research has suggested that self-relevance automatically enhances stimulus processing (i.e., the self-prioritization effect). Notably, information associated with one’s self elicits faster responses than comparable material associated with other targets (e.g., friend, stranger). Challenging the assertion that self-prioritization is an obligatory process, here we hypothesized that self-relevance only facilitates performance when task sets draw attention to previously formed target-object associations. The results of two experiments were consistent with this viewpoint. Compared with arbitrary objects owned by a friend, those owned by the self were classified more rapidly when participants were required to report either the owner or identity of the items (i.e., semantic task set). In contrast, self-relevance failed to facilitate performance when participants judged the orientation of the stimuli (i.e., perceptual task set). These findings demonstrate the conditional automaticity of self-prioritization during stimulus processing

    The ALMA Protostellar Interferometric Line Survey (PILS): First results from an unbiased submillimeter wavelength line survey of the Class 0 protostellar binary IRAS 16293-2422 with ALMA

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    The inner regions of the envelopes surrounding young protostars are characterised by a complex chemistry, with prebiotic molecules present on the scales where protoplanetary disks eventually may form. This paper introduces a systematic survey, "Protostellar Interferometric Line Survey (PILS)" of the Class 0 protostellar binary IRAS 16293-2422 using the Atacama Large Millimeter/submillimeter Array (ALMA). The survey covers the full frequency range from 329 to 363 GHz (0.8 mm) with additional targeted observations at 3.0 and 1.3 mm. More than 10,000 features are detected toward one component in the protostellar binary. Glycolaldehyde, its isomers, methyl formate and acetic acid, and its reduced alcohol, ethylene glycol, are clearly detected. For ethylene glycol both lowest state conformers, aGg' and gGg', are detected, the latter for the first time in the ISM. The abundance of glycolaldehyde is comparable to or slightly larger than that of ethylene glycol. In comparison to the Galactic Center, these two species are over-abundant relative to methanol, possibly an indication of formation at low temperatures in CO-rich ices. Both 13C and deuterated isotopologues of glycolaldehyde are detected, also for the first time ever in the ISM. For the deuterated species, a D/H ratio of approximately 5% is found with no differences between the deuteration in the different functional groups of glycolaldehyde. Measurements of the 13C-species lead to a 12C:13C ratio of approximately 30, lower than the typical ISM value. This low ratio may reflect an enhancement of 13CO in the ice due to either ion-molecule reactions in the gas before freeze-out or differences in the temperatures where 12CO and 13CO ices sublimate. The results reinforce the importance of low-temperature grain surface chemistry for the formation of prebiotic molecules seen here in the gas after sublimation of the entire ice mantle

    More or less of me and you: self-relevance augments the effects of item probability on stimulus prioritization

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    AbstractSelf-relevance exerts a powerful influence on information processing. Compared to material associated with other people, personally meaningful stimuli are prioritized during decision-making. Further exploring the character of this effect, here we considered the extent to which stimulus enhancement is impacted by the frequency of self-relevant versus friend-relevant material. In a matching task, participants reported whether shape-label stimulus pairs corresponded to previously learned associations (e.g., triangle = self, square = friend). Crucially however, before the task commenced, stimulus-based expectancies were provided indicating the probability with which both self- and friend-related shapes would be encountered. The results revealed that task performance was impacted by the frequency of stimulus presentation in combination with the personal relevance of the items. When self- and friend-related shapes appeared with equal frequencies, a self-prioritization effect emerged (Expt. 1). Additionally, in both confirmatory (Expt. 2) and dis-confirmatory (Expt. 3) task contexts, stimuli that were encountered frequently (vs. infrequently) were prioritized, an effect that was most pronounced for self-relevant (vs. friend-relevant) items. Further computational analyses indicated that, in each of the reported experiments, differences in performance were underpinned by variation in the rate of information uptake, with evidence extracted more rapidly from self-relevant compared to friend-relevant stimuli. These findings advance our understanding of the emergence and origin of stimulus-prioritization effects during decisional processing.</jats:p

    Serum methylarginines and spirometry-measured lung function in older adults

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    Rationale: Methylarginines are endogenous nitric oxide synthase inhibitors that have been implicated in animal models of lung disease but have not previously been examined for their association with spirometric measures of lung function in humans. Objectives: This study measured serum concentrations of asymmetric and symmetric dimethylarginine in a representative sample of older community-dwelling adults and determined their association with spirometric lung function measures. Methods: Data on clinical, lifestyle, and demographic characteristics, methylated arginines, and L-arginine (measured using LC-MS/MS) were collected from a population-based sample of older Australian adults from the Hunter Community Study. The five key lung function measures included as outcomes were Forced Expiratory Volume in 1 second, Forced Vital Capacity, Forced Expiratory Volume in 1 second to Forced Vital Capacity ratio, Percent Predicted Forced Expiratory Volume in 1 second, and Percent Predicted Forced Vital Capacity. Measurements and Main Results: In adjusted analyses there were statistically significant independent associations between a) higher asymmetric dimethylarginine, lower Forced Expiratory Volume in 1 second and lower Forced Vital Capacity; and b) lower L-arginine/asymmetric dimethylarginine ratio, lower Forced Expiratory Volume in 1 second, lower Percent Predicted Forced Expiratory Volume in 1 second and lower Percent Predicted Forced Vital Capacity. By contrast, no significant associations were observed between symmetric dimethylarginine and lung function. Conclusions: After adjusting for clinical, demographic, biochemical, and pharmacological confounders, higher serum asymmetric dimethylarginine was independently associated with a reduction in key measures of lung function. Further research is needed to determine if methylarginines predict the decline in lung function

    A Triple Protostar System Formed via Fragmentation of a Gravitationally Unstable Disk

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    Binary and multiple star systems are a frequent outcome of the star formation process, and as a result, almost half of all sun-like stars have at least one companion star. Theoretical studies indicate that there are two main pathways that can operate concurrently to form binary/multiple star systems: large scale fragmentation of turbulent gas cores and filaments or smaller scale fragmentation of a massive protostellar disk due to gravitational instability. Observational evidence for turbulent fragmentation on scales of >>1000~AU has recently emerged. Previous evidence for disk fragmentation was limited to inferences based on the separations of more-evolved pre-main sequence and protostellar multiple systems. The triple protostar system L1448 IRS3B is an ideal candidate to search for evidence of disk fragmentation. L1448 IRS3B is in an early phase of the star formation process, likely less than 150,000 years in age, and all protostars in the system are separated by <<200~AU. Here we report observations of dust and molecular gas emission that reveal a disk with spiral structure surrounding the three protostars. Two protostars near the center of the disk are separated by 61 AU, and a tertiary protostar is coincident with a spiral arm in the outer disk at a 183 AU separation. The inferred mass of the central pair of protostellar objects is \sim1 Msun_{sun}, while the disk surrounding the three protostars has a total mass of \sim0.30 M_{\sun}. The tertiary protostar itself has a minimum mass of \sim0.085 Msun_{sun}. We demonstrate that the disk around L1448 IRS3B appears susceptible to disk fragmentation at radii between 150~AU and 320~AU, overlapping with the location of the tertiary protostar. This is consistent with models for a protostellar disk that has recently undergone gravitational instability, spawning one or two companion stars.Comment: Published in Nature on Oct. 27th. 24 pages, 8 figure

    Changes in Parasite Virulence Induced by the Disruption of a Single Member of the 235 kDa Rhoptry Protein Multigene Family of Plasmodium yoelii

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    Invasion of the erythrocyte by the merozoites of the malaria parasite is a complex process involving a range of receptor-ligand interactions. Two protein families termed Erythrocyte Binding Like (EBL) proteins and Reticulocyte Binding Protein Homologues (RH) play an important role in host cell recognition by the merozoite. In the rodent malaria parasite, Plasmodium yoelii, the 235 kDa rhoptry proteins (Py235) are coded for by a multigene family and are members of the RH. In P. yoelii Py235 as well as a single member of EBL have been shown to be key mediators of virulence enabling the parasite to invade a wider range of host erythrocytes. One member of Py235, PY01365 is most abundantly transcribed in parasite populations and the protein specifically binds to erythrocytes and is recognized by the protective monoclonal antibody 25.77, suggesting a key role of this particular member in virulence. Recent studies have indicated that overall levels of Py235 expression are essential for parasite virulence. Here we show that disruption of PY01365 in the virulent YM line directly impacts parasite virulence. Furthermore the disruption of PY01365 leads to a reduction in the number of schizonts that express members of Py235 that react specifically with the mcAb 25.77. Erythrocyte binding assays show reduced binding of Py235 to red blood cells in the PY01365 knockout parasite as compared to YM. While our results identify PY01365 as a mediator of parasite virulence, they also confirm that other members of Py235 are able to substitute for PY01365

    Inequality and the composition of taxes

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    This paper analyzes the political economics of the composition of taxes. Taxes may be levied on income, or on expenditure, with the median voter pivotal in the theoretical framework analyzed. As in Meltzer and Richard (1981) income taxes increase with inequality. Conversely expenditure taxes first increase and then decrease with increasing inequality. The extent to which taxes are levied on income relative to expenditure unambiguously rises with inequality. In contrast to government size evidence, cross-country data exhibit a robust positive correlation between the extent to which taxes are levied on income relative to expenditure, and inequality. Consistent with the theory this relationship holds most significantly in stronger democracies
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