2,055 research outputs found

    Experimental demonstration of four-party quantum secret sharing

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    Secret sharing is a multiparty cryptographic task in which some secret information is splitted into several pieces which are distributed among the participants such that only an authorized set of participants can reconstruct the original secret. Similar to quantum key distribution, in quantum secret sharing, the secrecy of the shared information relies not on computational assumptions, but on laws of quantum physics. Here, we present an experimental demonstration of four-party quantum secret sharing via the resource of four-photon entanglement

    Allelopathic effects of invasive Eucalyptus camaldulensis on germination and early growth of four native species in the Western Cape, South Africa

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    Eucalyptus camaldulensis Dehnh. (red river gum; Myrtaceae) is an invasive tree in riparian habitats of the Western Cape, South Africa, where it replaces indigenous vegetation and affects ecosystem functioning. These invasions lead to changes in river geomorphology and reduction in stream flow. The mechanisms that drive these effects are poorly understood. The potential for allelopathic effects of aqueous extracts of E. camaldulensis tissues and of soil and litter collected beneath E. camaldulensis trees on the germination and seedling growth of four selected native plant species was investigated in a greenhouse experiment. Soils collected beneath E. camaldulensis trees were used in three treatments: untreated soils, sterilised soils and sterilised soils overlaid with a eucalypt litter layer. In addition, soils collected from underneath native species were used in two treatments: untreated soils and soils overlaid with a eucalypt litter layer. All soil treatments were watered with three E. camaldulensis leaf, bark and root aqueous treatments. Compounds present in the aqueous extracts and fresh samples were identified using gas chromatography. Soil and aqueous treatments showed varying effects on germination and seedling growth of the four native species. Germination and seedling growth of Olea europaea subsp. africana and Dimorphotheca pluvialis were significantly reduced by E. camaldulensis root and bark aqueous extracts as well as by the soils treatments. The addition of eucalypt litter to native and sterilised soils reduced shoot and root growth of all four native species. Compounds such as -phellandrene, eucalyptol, p-menth-1-en-8-ol and a-pinene, which have the potential to inhibit germination and plant growth, were identified in E. camaldulensis aqueous extracts and fresh samples. Although the methods applied in this study had limitations (e.g. lack of control treatment to litter addition), the results provide an additional motivation to prioritise removal of invasive E. camaldulensis stands from riparian ecosystems. Restoration initiatives should target native species that are not negatively affected by allelopathy

    Involvement of the G-protein-coupled dopamine/ecdysteroid receptor DopEcR in the behavioral response to sex pheromone in an insect

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    Most animals including insects rely on olfaction to find their mating partners. In moths, males are attracted by female-produced sex pheromones inducing stereotyped sexual behavior. The behaviorally relevant olfactory information is processed in the primary olfactory centre, the antennal lobe (AL). Evidence is now accumulating that modulation of sex-linked behavioral output occurs through neuronal plasticity via the action of hormones and/or catecholamines. A G-protein-coupled receptor (GPCR) binding to 20-hydroxyecdysone, the main insect steroid hormone, and dopamine, has been identified in Drosophila (DmDopEcR), and was suggested to modulate neuronal signaling. In the male moth Agrotis ipsilon, the behavioral and central nervous responses to pheromone are age-dependent. To further unveil the mechanisms of this olfactory plasticity, we searched for DopEcR and tested its potential role in the behavioral response to sex pheromone in A. ipsilon males. Our results show that A. ipsilon DopEcR (named AipsDopEcR) is predominantly expressed in the nervous system. The corresponding protein was detected immunohistochemically in the ALs and higher brain centers including the mushroom bodies. Moreover, AipsDopEcR expression increased with age. Using a strategy of RNA interference, we also show that silencing of AipsDopEcR inhibited the behavioral response to sex pheromone in wind tunnel experiments. Altogether our results indicate that this GPCR is involved in the expression of sexual behavior in the male moth, probably by modulating the central nervous processing of sex pheromone through the action of one or both of its ligands

    Promoting beliefs in the inalienability of human rights by attributing uniquely human emotions through multiple categorization

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    The combination of multiple categorization (i.e., the use of multiple criteria to define others) and human identity-the superordinate group of human beings-has recently been highlighted as a method to reduce implicit (i.e., attribution of secondary emotions) and explicit (i.e., attribution of human rights) dehumanization towards Blacks. In two studies aimed to replicate such evidence the mediating role of secondary emotions in explaining the impact of multiple and human categorization in reducing dehumanization was assessed. The role of implicit cognition such as attribution of secondary emotions in leading people to attribute human rights to minorities is discussed

    The Functional and Identity Indispensability Scale (FIIS)

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    This research further elaborated the concept of indispensability by developing and testing a new measure, the Functional and Identity Indispensability Scale (FIIS), to assess two dimensions on which groups can claim indispensability: functional indispensability and identity indispensability. In Study 1 we developed and validated the FIIS with a sample of 452 American college students. Results showed the expected two-factor structure and supported the prediction that identity and functional are two distinct, but related, forms of indispensability. FIIS showed a consistent structure across majority and minority members and the reliability of the two subscales was good. In Study 2, a sample of 154 White-American citizens evaluated the perceived indispensability (FIIS) of three minority groups: African-Americans, Hispanic-Americans, and Asian-Americans. Results showed the scale’s sensitivity. Participants attributed greater identity (vs. functional) indispensability to African-Americans, whereas the pattern was reversed for Asian-Americans. No differences were found for Hispanic-Americans. Criterion validity was supported by (a) positive associations with competence and warmth, (b) negative associations with negative emotions and with social distance towards all minority group targets. The psychometric properties of the FIIS suggest its potential to be valuable addition to the existing literature on common identities and intergroup relations.info:eu-repo/semantics/acceptedVersio

    Identity inclusiveness and centrality: investigating identity correlates of attitudes toward immigrants and immigration policies

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    Social psychology highlights ingroup identity as an important determinant of intergroup attitudes and relations; however, research has demonstrated that its effects can be positive, negative, or nonexistent depending on how such identity is conceptualized. This research explores how national identity inclusiveness (Study 1) and centrality (Study 2) are associated with immigration related attitudes in school and countrywide settings, respectively. Study 1 showed that teachers’ inclusive (i.e., overlapping) identities regarding their immigrant students related to positive attitudes toward these students, but not to attitudes about immigrants in general or immigration policy preferences. Study 2 found that national identity centrality was related to negative attitudes toward the social impact of immigrants, and to higher support for policies inhibiting the social inclusion of immigrants in the receiving community. Combined, these studies highlight the importance of considering different conceptualizations of ingroup identity in identifying relations to immigration‐based attitudes. Moreover, the studies highlight the value of promoting inclusive identities when aiming to improve attitudes toward immigrants. We conclude by discussing a new approach for promoting inclusive identities by framing immigrants as indispensable to the receiving community.info:eu-repo/semantics/acceptedVersio

    Little “We’s”: how common identities improve behavior differently for ethnic majority and minority children

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    This field experiment tested whether inducing common inclusive representations (i.e., one group, dual identity) during contact influences intergroup relations differently for ethnic majority and minority children by changing their metaperceptions and intergroup emotions differently. White (N = 113) and Black (N = 111) 8- to 10-year-old children were exposed to interactive mixed-ethnicity sessions in schools emphasizing either categorization as one group (national group), dual identity (national group with ethnic subgroups), or two ethnic groups. Overall, as predicted, for White children, one-group, but not dual-identity perceptions, improved behavioral intentions by influencing metaperceptions. For Black children, dual-identity, but not one-group, perceptions improved behavioral intentions through metaperceptions. Contrary to the expected, both dual-identity and one-group perceptions were associated with White and Black children’s intergroup emotions.info:eu-repo/semantics/acceptedVersio

    A solid-reagent dispenser for use in the azocoll protease assay (and other insoluble substrate analyses).

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    A solid-reagent dispenser for use in the azocoll protease assay (and other insoluble substrate analyses)

    Observations of the Sunyaev-Zel'dovich effect at high angular resolution towards the galaxy clusters A665, A2163 and CL0016+16

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    We report on the first observation of the Sunyaev-Zel'dovich effect with the Diabolo experiment at the IRAM 30 metre telescope. A significant brightness decrement is detected in the direction of three clusters (Abell 665, Abell 2163 and CL0016+16). With a 30 arcsecond beam and 3 arcminute beamthrow, this is the highest angular resolution observation to date of the SZ effect.Comment: 23 pages, 8 figures, 6 tables, accepted to New Astronom
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