63 research outputs found

    Origin of the hot gas in low-mass protostars, Herschel-PACS spectroscopy of HH 46

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    Aims. “Water In Star-forming regions with Herschel” (WISH) is a Herschel key programme aimed at understanding the physical and chemical structure of young stellar objects (YSOs) with a focus on water and related species. Methods. The low-mass protostar HH 46 was observed with the Photodetector Array Camera and Spectrometer (PACS) on the Herschel Space Observatory to measure emission in H2O, CO, OH, [O i], and [C ii] lines located between 63 and 186 μm. The excitation and spatial distribution of emission can disentangle the different heating mechanisms of YSOs, with better spatial resolution and sensitivity than previously possible. Results. Far-IR line emission is detected at the position of the protostar and along the outflow axis. The OH emission is concentrated at the central position, CO emission is bright at the central position and along the outflow, and H2O emission is concentrated in the outflow. In addition, [O i] emission is seen in low-velocity gas, assumed to be related to the envelope, and is also seen shifted up to 170 km s−1 in both the red- and blue-shifted jets. Envelope models are constructed based on previous observational constraints. They indicate that passive heating of a spherical envelope by the protostellar luminosity cannot explain the high-excitation molecular gas detected with PACS, including CO lines with upper levels at >2500 K above the ground state. Instead, warm CO and H2O emission is probably produced in the walls of an outflow-carved cavity in the envelope, which are heated by UV photons and non-dissociative C-type shocks. The bright OH and [Oi] emission is attributed to J-type shocks in dense gas close to the protostar. In the scenario described here, the combined cooling by far-IR lines within the central spatial pixel is estimated to be 2 × 10−2 L, with 60–80% attributed to J- and C-type shocks produced by interactions between the jet and the envelope

    Need satisfaction in intergroup contact:A multinational study of pathways toward social change

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    none43siFinanziamenti esterni a vari co-autoriWhat role does intergroup contact play in promoting support for social change toward greater social equality? Drawing on the needs-based model of reconciliation, we theorized that when inequality between groups is perceived as illegitimate, disadvantaged group members will experience a need for empowerment and advantaged group members a need for acceptance. When intergroup contact satisfies each group's needs, it should result in more mutual support for social change. Using four sets of survey data collected through the Zurich Intergroup Project in 23 countries, we tested several preregistered predictions, derived from the above reasoning, across a large variety of operationalizations. Two studies of disadvantaged groups (Ns = 689 ethnic minority members in Study 1 and 3,382 sexual/gender minorities in Study 2) support the hypothesis that, after accounting for the effects of intergroup contact and perceived illegitimacy, satisfying the need for empowerment (but not acceptance) during contact is positively related to support for social change. Two studies with advantaged groups (Ns = 2,937 ethnic majority members in Study 3 and 4,203 cis-heterosexual individuals in Study 4) showed that, after accounting for illegitimacy and intergroup contact, satisfying the need for acceptance (but also empowerment) is positively related to support for social change. Overall, findings suggest that intergroup contact is compatible with efforts to promote social change when group-specific needs are met. Thus, to encourage support for social change among both disadvantaged and advantaged group members, it is essential that, besides promoting mutual acceptance, intergroup contact interventions also give voice to and empower members of disadvantaged groups.mixedHässler, Tabea; Ullrich, Johannes; Sebben, Simone; Shnabel, Nurit; Bernardino, Michelle; Valdenegro, Daniel; Van Laar, Colette; González, Roberto; Visintin, Emilio Paolo; Tropp, Linda R; Ditlmann, Ruth K; Abrams, Dominic; Aydin, Anna Lisa; Pereira, Adrienne; Selvanathan, Hema Preya; von Zimmermann, Jorina; Lantos, Nóra Anna; Sainz, Mario; Glenz, Andreas; Kende, Anna; Oberpfalzerová, Hana; Bilewicz, Michal; Branković, Marija; Noor, Masi; Pasek, Michael H; Wright, Stephen C; Žeželj, Iris; Kuzawinska, Olga; Maloku, Edona; Otten, Sabine; Gul, Pelin; Bareket, Orly; Corkalo Biruski, Dinka; Mugnol-Ugarte, Luiza; Osin, Evgeny; Baiocco, Roberto; Cook, Jonathan E; Dawood, Maneeza; Droogendyk, Lisa; Loyo, Angélica Herrera; Jelić, Margareta; Kelmendi, Kaltrina; Pistella, JessicaHässler, Tabea; Ullrich, Johannes; Sebben, Simone; Shnabel, Nurit; Bernardino, Michelle; Valdenegro, Daniel; Van Laar, Colette; González, Roberto; Visintin, Emilio Paolo; Tropp, Linda R; Ditlmann, Ruth K; Abrams, Dominic; Aydin, Anna Lisa; Pereira, Adrienne; Selvanathan, Hema Preya; von Zimmermann, Jorina; Lantos, Nóra Anna; Sainz, Mario; Glenz, Andreas; Kende, Anna; Oberpfalzerová, Hana; Bilewicz, Michal; Branković, Marija; Noor, Masi; Pasek, Michael H; Wright, Stephen C; Žeželj, Iris; Kuzawinska, Olga; Maloku, Edona; Otten, Sabine; Gul, Pelin; Bareket, Orly; Corkalo Biruski, Dinka; Mugnol-Ugarte, Luiza; Osin, Evgeny; Baiocco, Roberto; Cook, Jonathan E; Dawood, Maneeza; Droogendyk, Lisa; Loyo, Angélica Herrera; Jelić, Margareta; Kelmendi, Kaltrina; Pistella, Jessic

    Many analysts, one data set: making transparent how variations in analytic choices affect results

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    Twenty-nine teams involving 61 analysts used the same data set to address the same research question: whether soccer referees are more likely to give red cards to dark-skin-toned players than to light-skin-toned players. Analytic approaches varied widely across the teams, and the estimated effect sizes ranged from 0.89 to 2.93 (Mdn = 1.31) in odds-ratio units. Twenty teams (69%) found a statistically significant positive effect, and 9 teams (31%) did not observe a significant relationship. Overall, the 29 different analyses used 21 unique combinations of covariates. Neither analysts’ prior beliefs about the effect of interest nor their level of expertise readily explained the variation in the outcomes of the analyses. Peer ratings of the quality of the analyses also did not account for the variability. These findings suggest that significant variation in the results of analyses of complex data may be difficult to avoid, even by experts with honest intentions. Crowdsourcing data analysis, a strategy in which numerous research teams are recruited to simultaneously investigate the same research question, makes transparent how defensible, yet subjective, analytic choices influence research results

    Low Cost Tuberculosis Vaccine Antigens in Capsules: Expression in Chloroplasts, Bio-Encapsulation, Stability and Functional Evaluation In Vitro

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    Tuberculosis (TB) caused by Mycobacterium tuberculosis is one of the leading fatal infectious diseases. The development of TB vaccines has been recognized as a major public health priority by the World Health Organization. In this study, three candidate antigens, ESAT-6 (6kDa early secretory antigenic target) and Mtb72F (a fusion polyprotein from two TB antigens, Mtb32 and Mtb39) fused with cholera toxin B-subunit (CTB) and LipY (a cell wall protein) were expressed in tobacco and/or lettuce chloroplasts to facilitate bioencapsulation/oral delivery. Site-specific transgene integration into the chloroplast genome was confirmed by Southern blot analysis. In transplastomic leaves, CTB fusion proteins existed in soluble monomeric or multimeric forms of expected sizes and their expression levels varied depending upon the developmental stage and time of leaf harvest, with the highest-level of accumulation in mature leaves harvested at 6PM. The CTB-ESAT6 and CTB-Mtb72F expression levels reached up to 7.5% and 1.2% of total soluble protein respectively in mature tobacco leaves. Transplastomic CTB-ESAT6 lettuce plants accumulated up to 0.75% of total leaf protein. Western blot analysis of lyophilized lettuce leaves stored at room temperature for up to six months showed that the CTB-ESAT6 fusion protein was stable and preserved proper folding, disulfide bonds and assembly into pentamers for prolonged periods. Also, antigen concentration per gram of leaf tissue was increased 22 fold after lyophilization. Hemolysis assay with purified CTB-ESAT6 protein showed partial hemolysis of red blood cells and confirmed functionality of the ESAT-6 antigen. GM1-binding assay demonstrated that the CTB-ESAT6 fusion protein formed pentamers to bind with the GM1-ganglioside receptor. The expression of functional Mycobacterium tuberculosis antigens in transplastomic plants should facilitate development of a cost-effective and orally deliverable TB booster vaccine with potential for long-term storage at room temperature. To our knowledge, this is the first report of expression of TB vaccine antigens in chloroplasts

    Modeling the interactions between river morphodynamics and riparian vegetation

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    The study of river-riparian vegetation interactions is an important and intriguing research field in geophysics. Vegetation is an active element of the ecological dynamics of a floodplain which interacts with the fluvial processes and affects the flow field, sediment transport, and the morphology of the river. In turn, the river provides water, sediments, nutrients, and seeds to the nearby riparian vegetation, depending on the hydrological, hydraulic, and geomorphological characteristic of the stream. In the past, the study of this complex theme was approached in two different ways. On the one hand, the subject was faced from a mainly qualitative point of view by ecologists and biogeographers. Riparian vegetation dynamics and its spatial patterns have been described and demonstrated in detail, and the key role of several fluvial processes has been shown, but no mathematical models have been proposed. On the other hand, the quantitative approach to fluvial processes, which is typical of engineers, has led to the development of several morphodynamic models. However, the biological aspect has usually been neglected, and vegetation has only been considered as a static element. In recent years, different scientific communities (ranging from ecologists to biogeographers and from geomorphologists to hydrologists and fluvial engineers) have begun to collaborate and have proposed both semiquantitative and quantitative models of river-vegetation interconnections. These models demonstrate the importance of linking fluvial morphodynamics and riparian vegetation dynamics to understand the key processes that regulate a riparian environment in order to foresee the impact of anthropogenic actions and to carefully manage and rehabilitate riparian areas. In the first part of this work, we review the main interactions between rivers and riparian vegetation, and their possible modeling. In the second part, we discuss the semiquantitative and quantitative models which have been proposed to date, considering both multi- and single-thread river

    Chloroplast genomes: diversity, evolution, and applications in genetic engineering

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