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Entropy Determination of Single-Phase High Entropy Alloys with Different Crystal Structures over a Wide Temperature Range
We determined the entropy of high entropy alloys by investigating single-crystalline nickel and five high entropy alloys: two fcc-alloys, two bcc-alloys and one hcp-alloy. Since the configurational entropy of these single-phase alloys differs from alloys using a base element, it is important to quantify the entropy. Using differential scanning calorimetry, cp-measurements are carried out from −170 °C to the materials’ solidus temperatures TS. From these experiments, we determined the thermal entropy and compared it to the configurational entropy for each of the studied alloys. We applied the rule of mixture to predict molar heat capacities of the alloys at room temperature, which were in good agreement with the Dulong-Petit law. The molar heat capacity of the studied alloys was about three times the universal gas constant, hence the thermal entropy was the major contribution to total entropy. The configurational entropy, due to the chemical composition and number of components, contributes less on the absolute scale. Thermal entropy has approximately equal values for all alloys tested by DSC, while the crystal structure shows a small effect in their order. Finally, the contributions of entropy and enthalpy to the Gibbs free energy was calculated and examined and it was found that the stabilization of the solid solution phase in high entropy alloys was mostly caused by increased configurational entropy
Aplastic Crisis as Primary Manifestation of Systemic Lupus Erythematosus
Aplastic crisis is an unusual feature of systemic lupus erythematosus (SLE). We report the case of a 54-year-old woman presenting with both (extravascular) Coombs-positive hemolytic anemia and laboratory findings of bone marrow hyporegeneration with concomitant severe neutropenia. A bone marrow biopsy confirmed aplastic crisis. Diagnostic work-up revealed soaring titers of autoantibodies (anti-nuclear, anti-double-stranded DNA, anti-cardiolipin-IgM, and anti-beta 2-glykoprotein-IgM antibodies), indicating a connective tissue disease as the most plausible reason for bone marrow insufficiency. As the criteria for SLE were fulfilled, we initiated an immunosuppressive therapy by steroids, which led to a rapid complete hematologic and clinical remission in our patient. In this case, we could report on one of the rare cases of SLE-induced aplastic crisis showing that this condition can be entirely reversed by immunosuppressive treatment and that SLE-induced aplastic crisis yields a good prognosis. In conclusion, in a case of aplastic crisis, physicians should be aware that SLE can be a rare cause that is accessible to specific treatment
Imaging the Ettingshausen effect and cryogenic thermoelectric cooling in a van der Waals semimetal
Attaining viable thermoelectric cooling at cryogenic temperatures is of major
fundamental and technological interest for novel electronics and quantum
materials applications. In-device temperature control can provide a more
efficient and precise thermal environment management as compared to the
conventional global cooling. Here we develop nanoscale cryogenic imaging of a
magneto-thermoelectric effect and demonstrate absolute cooling and an ultrahigh
Ettingshausen effect in exfoliated WTe2 Weyl semimetal flakes at liquid He
temperatures. Application of a current and perpendicular magnetic field gives
rise to cooling via generation of electron-hole pairs on one side of the sample
and heating by their recombination at the opposite side. In contrast to bulk
materials, the cooling process is found to be nonmonotonic in magnetic field
and device size. The derived model of magneto-thermoelectricity in mesoscopic
semimetal devices shows that the cooling efficiency and the induced temperature
profiles are governed by the interplay between sample geometry, electron-hole
recombination length, magnetic field, and flake and substrate heat
conductivities. The findings open the way for direct integration of microscopic
thermoelectric cooling and for temperature landscape engineering in novel van
der Waals devices
Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at = 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 5.0 GeV/ 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
. 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
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 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
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
which is indicative of a Bessel-Gaussian
function for the 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 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
How a slow-ovipositing parasitoid can succed as a biological control agent of the invasive mealybug Phenacoccus peruvianus: implications for future classical and conservation biological control programs
[EN] Phenaccocus peruvianus Granara de Willink (Hemiptera: pseudococcidae) is an invasive mealybug that has become a pest of ornamental plants in Europe and has recently been detected in California, USA. In this work, we studied the tritrophic interaction among this mealybug, its main parasitoid Acerophagus n. sp. near coccois (Hymenoptera: Encyrtidae) and tending ants to disclose the success of this parasitoid controlling P. peruvianus. Acerophagus n. sp. near coccois accepted mealybugs for parasitism regardless of their size but did not hostfeed. We recorded three active defenses of P. peruvianus. Host handling time-consuming process that required more than 30 min. Tending ants, Lasius grandis (Hymenoptera: Encyrtidae), reduced the time spent by parasitoids in a patch and disrupted oviposition attempts. The low numbers of ants tending mealybugs colonies in Spain and France could explain why this parasitoid, with a long handling time, is an efficient biological control agent for P. peruvianus.Beltrà Ivars, A.; Soto Sánchez, AI.; Tena Barreda, A. (2015). How a slow-ovipositing parasitoid can succed as a biological control agent of the invasive mealybug Phenacoccus peruvianus: implications for future classical and conservation biological control programs. BioControl. 60(4):473-484. https://doi.org/10.1007/s10526-015-9663-6S473484604Arakelian G (2013) Bougainvillea mealybug (Phenacoccus peruvianus). Factsheet 2013. County of Los Angeles. Department of agricultural commissioner/weights and measures, USABartlett BR (1961) The influence of ants upon parasites, predators, and scale insects. Ann Entomol Soc Am 54:543–551Bartlett BR (1978) Pseudococcidae. In: Clausen CP (ed) Introduced parasites and predators of arthropod pests and weeds: a world review, 1st edn. 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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
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
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