Effect of Wall Thickness and Surface Conditions on Creep Behavior of a Single-Crystal Ni-Based Superalloy

The influence of wall thickness and specimen surface on the creep behavior of the single-crystal nickel-based superalloy MAR M247LC is studied. Specimens with wall thicknesses of 0.4, 0.8, 1 and 2 mm, with and without casting surface, are compared to specimens of the same wall thickness prepared from bulk material. Creep behavior turned out to be independent from surface conditions even for the thinnest specimens. The thickness debit effect is not pronounced for short creep rupture times (le;100 h at 980 deg;C), whereas it is significant for creep rupture times longer than ~200 h at 980 deg;C. The thickness debit effect is time-dependent and caused by oxidation and diffusion-controlled mechanisms

Spin dephasing and photoinduced spin diffusion in high-mobility 110-grown GaAs-AlGaAs two-dimensional electron systems

We have studied spin dephasing and spin diffusion in a high-mobility two-dimensional electron system, embedded in a GaAs/AlGaAs quantum well grown in the [110] direction, by a two-beam Hanle experiment. For very low excitation density, we observe spin lifetimes of more than 16 ns, which rapidly decrease as the pump intensity is increased. Two mechanisms contribute to this decrease: the optical excitation produces holes, which lead to a decay of electron spin via the Bir-Aranov-Pikus mechanism and recombination with spin-polarized electrons. By scanning the distance between the pump and probe beams, we observe the diffusion of spin-polarized electrons over more than 20 microns. For high pump intensity, the spin polarization in a distance of several microns from the pump beam is larger than at the pump spot, due to the reduced influence of photogenerated holes.Comment: 4 pages, 3 figure

An integrative approach to more nuanced estimates of personality–job–performance relations

This is the final version. Available on open access from Wiley via the DOI in this recordData availability statement: The data that support the findings of this study are openly available on OSF at https://osf.io/ys72j/?view_only=f48aeaf9414d46fb81019186030afbdcRecent research has suggested that self- and other-ratings of personality may provide different information about personality, which can be captured in the trait–reputation–identity (TRI) model. Based on the TRI model, we investigate the link between personality and aligned job performance criteria on domain and aspect levels of the Big Five personality traits. In five samples (overall N = 571 triplets of target self-ratings and two coworker other-ratings), we investigated the relationships between the shared information on personality and shared information about job performance. We found that all personality domains showed substantial criterion validity in predicting the corresponding job-performance dimensions. Furthermore, we found stronger estimates for aspects of agreeableness and openness. We discuss theoretical and practical implications for target replacement and performance management

Multi-particle azimuthal correlations in p-Pb and Pb-Pb collisions at the CERN Large Hadron Collider

Measurements of multi-particle azimuthal correlations (cumulants) for charged particles in p-Pb and Pb-Pb collisions are presented. They help address the question of whether there is evidence for global, flow-like, azimuthal correlations in the p-Pb system. Comparisons are made to measurements from the larger Pb-Pb system, where such evidence is established. In particular, the second harmonic two-particle cumulants are found to decrease with multiplicity, characteristic of a dominance of few-particle correlations in p-Pb collisions. However, when a $|\Delta \eta|$ gap is placed to suppress such correlations, the two-particle cumulants begin to rise at high-multiplicity, indicating the presence of global azimuthal correlations. The Pb-Pb values are higher than the p-Pb values at similar multiplicities. In both systems, the second harmonic four-particle cumulants exhibit a transition from positive to negative values when the multiplicity increases. The negative values allow for a measurement of $v_{2}\{4\}$ to be made, which is found to be higher in Pb-Pb collisions at similar multiplicities. The second harmonic six-particle cumulants are also found to be higher in Pb-Pb collisions. In Pb-Pb collisions, we generally find $v_{2}\{4\} \simeq v_{2}\{6\}\neq 0$ which is indicative of a Bessel-Gaussian function for the $v_{2}$ distribution. For very high-multiplicity Pb-Pb collisions, we observe that the four- and six-particle cumulants become consistent with 0. Finally, third harmonic two-particle cumulants in p-Pb and Pb-Pb are measured. These are found to be similar for overlapping multiplicities, when a $|\Delta\eta| > 1.4$ gap is placed.Comment: 25 pages, 11 captioned figures, 3 tables, authors from page 20, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/87

Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at sNN\sqrt{s_{NN}} = 5.02 TeV

Two-particle angular correlations between unidentified charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum range 0.7 $< p_{\rm{T}, assoc} < p_{\rm{T}, trig} <$ 5.0 GeV/$c$ is examined, to include correlations induced by jets originating from low momen\-tum-transfer scatterings (minijets). The correlations expressed as associated yield per trigger particle are obtained in the pseudorapidity range $|\eta|<0.9$. The near-side long-range pseudorapidity correlations observed in high-multiplicity p-Pb collisions are subtracted from both near-side short-range and away-side correlations in order to remove the non-jet-like components. The yields in the jet-like peaks are found to be invariant with event multiplicity with the exception of events with low multiplicity. This invariance is consistent with the particles being produced via the incoherent fragmentation of multiple parton--parton scatterings, while the yield related to the previously observed ridge structures is not jet-related. The number of uncorrelated sources of particle production is found to increase linearly with multiplicity, suggesting no saturation of the number of multi-parton interactions even in the highest multiplicity p-Pb collisions. Further, the number scales in the intermediate multiplicity region with the number of binary nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/161

Ants impact the energy reserves of natural enemies through the shared honeydew exploitation

[EN] Ants, as well as many species of parasitoids and predators, rely on sugar-richfoodssuchashoneydewtofulfilltheirenergeticneeds.Thus,antsandnatural enemies may interact through the shared honeydew exploitation. 2.Ant-exclusionexperimentswereperformedinacitrusorchardtotestthehypothesis that ants may impact the energy reserves of predators and parasitoids through the competitionforhoneydew.Throughtheuseofhigh-performanceliquidchromatography (HPLC)thelevelofantactivitywiththeenergyreservesandfeedinghistoryofindividual specimens collected in the field during representative days of spring, summer, and autumn were related. 3. Out of 145 Aphytis chrysomphali Mercet parasitoids captured in the field, 65% were classified as sugar-fed and 24.7% as honeydew-fed. In summer, when ant activity peaked,therewasasignificant negativecorrelationbetweenthelevelofantactivityand the total sugar content and honeydew feeding incidence by A.chrysomphali. Out of 47 individuals of the predator Chrysoperla carnea sensu lato (Stephens), captured in the field, 55.3% were classified as sugar-fed. We found a significant negative effect of the level of ant activity on the sugar-feeding incidence by C.carneain spring. 4.Thepresentstudyprovidesevidencethatantscaninterferewiththeenergyreserves of natural enemies. This interaction may be widespread in various ecosystems with important consequences for the arthropod community composition and with practical implicationsforbiologicalcontrolgiventhatabsenceofsugarfeedingisdetrimentalfor thefitness of many species of predatorsand parasitoidsDr Jerome Casas is greatly acknowledged for valuable comments on earlier versions of the manuscript and Dr Petr Duelli for providing help with the Chrysoperla identifications. We also thank Dr Cristina Navarro Campos and Dr Aleixandre Beltra for their help in the field samplings and for stimulating discussions, Barbara Rodriguez for help in the laboratory analyses and the reviewers for their helpful comments. This work was supported by the project (RTA2010-00012-C02-02) assigned to F. G. M from the Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (INIA), Spain and the project (BIO2013-48779-C4-1-R) from Spanish Ministry of Science and Innovation and COST action CM1303 on Systems Biocatalysis.Calabuig Gomar, A.; Tena Barreda, A.; Wäkers, FL.; Lucia Fernandez-Arrojo; Plou, FJ.; García Mari, F.; Pekas, A. (2015). Ants impact the energy reserves of natural enemies through the shared honeydew exploitation. Ecological Entomology. 40:687-695. https://doi.org/10.1111/een.12237S68769540Avidov, Z., Balshin, M., & Gerson, U. (1970). Studies onAphytis coheni, a parasite of the California red scale,Aonidiella aurantii in Israel. 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A distinct CD38+CD45RA+ population of CD4+, CD8+, and double-negative T cells is controlled by FAS.

The identification and characterization of rare immune cell populations in humans can be facilitated by their growth advantage in the context of specific genetic diseases. Here, we use autoimmune lymphoproliferative syndrome to identify a population of FAS-controlled TCRαβ+ T cells. They include CD4+, CD8+, and double-negative T cells and can be defined by a CD38+CD45RA+T-BET- expression pattern. These unconventional T cells are present in healthy individuals, are generated before birth, are enriched in lymphoid tissue, and do not expand during acute viral infection. They are characterized by a unique molecular signature that is unambiguously different from other known T cell differentiation subsets and independent of CD4 or CD8 expression. Functionally, FAS-controlled T cells represent highly proliferative, noncytotoxic T cells with an IL-10 cytokine bias. Mechanistically, regulation of this physiological population is mediated by FAS and CTLA4 signaling, and its survival is enhanced by mTOR and STAT3 signals. Genetic alterations in these pathways result in expansion of FAS-controlled T cells, which can cause significant lymphoproliferative disease

Plant Species Loss Affects Life-History Traits of Aphids and Their Parasitoids

The consequences of plant species loss are rarely assessed in a multi-trophic context and especially effects on life-history traits of organisms at higher trophic levels have remained largely unstudied. We used a grassland biodiversity experiment and measured the effects of two components of plant diversity, plant species richness and the presence of nitrogen-fixing legumes, on several life-history traits of naturally colonizing aphids and their primary and secondary parasitoids in the field. We found that, irrespective of aphid species identity, the proportion of winged aphid morphs decreased with increasing plant species richness, which was correlated with decreasing host plant biomass. Similarly, emergence proportions of parasitoids decreased with increasing plant species richness. Both, emergence proportions and proportions of female parasitoids were lower in plots with legumes, where host plants had increased nitrogen concentrations. This effect of legume presence could indicate that aphids were better defended against parasitoids in high-nitrogen environments. Body mass of emerged individuals of the two most abundant primary parasitoid species was, however, higher in plots with legumes, suggesting that once parasitoids could overcome aphid defenses, they could profit from larger or more nutritious hosts. Our study demonstrates that cascading effects of plant species loss on higher trophic levels such as aphids, parasitoids and secondary parasitoids begin with changed life-history traits of these insects. Thus, life-history traits of organisms at higher trophic levels may be useful indicators of bottom-up effects of plant diversity on the biodiversity of consumers

The Effects of Aphid Traits on Parasitoid Host Use and Specialist Advantage

Specialization is a central concept in ecology and one of the fundamental properties of parasitoids. Highly specialized parasitoids tend to be more efficient in host-use compared to generalized parasitoids, presumably owing to the trade-off between host range and hostuse efficiency. However, it remains unknown how parasitoid host specificity and host-use depends on host traits related to susceptibility to parasitoid attack. To address this question, we used data from a 13-year survey of interactions among 142 aphid and 75 parasitoid species in nine European countries. We found that only aphid traits related to local resource characteristics seem to influence the trade-off between host-range and efficiency: more specialized parasitoids had an apparent advantage (higher abundance on shared hosts) on aphids with sparse colonies, ant-attendance and without concealment, and this was more evident when host relatedness was included in calculation of parasitoid specificity. More traits influenced average assemblage specialization, which was highest in aphids that are monophagous, monoecious, large, highly mobile (easily drop from a plant), without myrmecophily, habitat specialists, inhabit non-agricultural habitats and have sparse colonies. Differences in aphid wax production did not influence parasitoid host specificity and host-use. Our study is the first step in identifying host traits important for aphid parasitoid host specificity and host-use and improves our understanding of bottom-up effects of aphid traits on aphid-parasitoid food web structure