103 research outputs found
Scanning Electron Microscope Study of Wohlfahrtia magnifica (Schiner, 1862) (Diptera: Sarcophagidae) I. Structures with Parasitic and Possible Taxonomic Meaning
The larval development of Wohlfahrtia magnifica (the most important dipteran causing sheep myiasis in the Palearctic region) has been studied by means of scanning electron microscopy. The ultrastructure of mouth-hooks, oral ridges, labial lobes, body spines and anterior and posterior peritremes is described for the first time. Their possible adaptations to a parasitic lifeway are also discussed. Thus, the use of new structures in the Sarcophagidae taxonomy is proposed from the point of view of their ultrastructure and adaptative morphology
Functional upgrading in China’s export processing sector
Functional upgrading occurs when a firm acquires more sophisticated functions within an existing value chain. In this paper, we analyze if there is evidence of this type of upgrading in China’s export processing regime by investigating dynamics in the relative prevalence of Import & Assembly (IA) versus Pure Assembly (PA) processing trade over the period 2000-2013. Firms in both regimes provide similar manufacturing services to foreign companies, but IA firms also conduct the sophisticated tasks of quality control, searching, financing and storing imported materials. Consistent with a trend of functional upgrading, we show that the share of IA trade in total processing trade has increased rapidly during the period 2000-2006, both overall and within product categories. Furthermore, we find that this trend has gone hand in hand with improvements in a sector’s labor productivity and unit values. Against expectations, we find that this process has slowed down notably during the period 2006-2013.status: publishe
Temperature chaos is present in off-equilibrium spin-glass dynamics
Experiments featuring non-equilibrium glassy dynamics under temperature changes still await interpretation. There is a widespread feeling that temperature chaos (an extreme sensitivity of the glass to temperature changes) should play a major role but, up to now, this phenomenon has been investigated solely under equilibrium conditions. In fact, the very existence of a chaotic effect in the non-equilibrium dynamics is yet to be established. In this article, we tackle this problem through a large simulation of the 3D Edwards-Anderson model, carried out on the Janus II supercomputer. We find a dynamic effect that closely parallels equilibrium temperature chaos. This dynamic temperature-chaos effect is spatially heterogeneous to a large degree and turns out to be controlled by the spin-glass coherence length ¿. Indeed, an emerging length-scale ¿* rules the crossover from weak (at ¿ « ¿*) to strong chaos (¿ » ¿*). Extrapolations of ¿* to relevant experimental conditions are provided. © 2021, The Author(s)
Scaling law describes the spin-glass response in theory, experiments and simulations
The correlation length , a key quantity in glassy dynamics, can now be
precisely measured for spin glasses both in experiments and in simulations.
However, known analysis methods lead to discrepancies either for large external
fields or close to the glass temperature. We solve this problem by introducing
a scaling law that takes into account both the magnetic field and the
time-dependent spin-glass correlation length. The scaling law is successfully
tested against experimental measurements in a CuMn single crystal and against
large-scale simulations on the Janus II dedicated computer.Comment: Revised version, including supplemental materia
Spin-glass dynamics in the presence of a magnetic field: exploration of microscopic properties
The synergy between experiment, theory, and simulations enables a microscopic
analysis of spin-glass dynamics in a magnetic field in the vicinity of and
below the spin-glass transition temperature . The spin-glass
correlation length, , is analysed both in experiments
and in simulations in terms of the waiting time after the spin
glass has been cooled down to a stabilised measuring temperature
and of the time after the magnetic field is changed. This
correlation length is extracted experimentally for a CuMn 6 at. % single
crystal, as well as for simulations on the Janus II special-purpose
supercomputer, the latter with time and length scales comparable to experiment.
The non-linear magnetic susceptibility is reported from experiment and
simulations, using as the scaling variable. Previous
experiments are reanalysed, and disagreements about the nature of the Zeeman
energy are resolved. The growth of the spin-glass magnetisation in zero-field
magnetisation experiments, , is measured from
simulations, verifying the scaling relationships in the dynamical or
non-equilibrium regime. Our preliminary search for the de Almeida-Thouless line
in is discussed.Comment: 49 pages, figures 2
Temperature chaos is present in off-equilibrium spin-glass dynamics
We find a dynamic effect in the non-equilibrium dynamics of a spin glass that
closely parallels equilibrium temperature chaos. This effect, that we name
dynamic temperature chaos, is spatially heterogeneous to a large degree. The
key controlling quantity is the time-growing spin-glass coherence length. Our
detailed characterization of dynamic temperature chaos paves the way for the
analysis of recent and forthcoming experiments. This work has been made
possible thanks to the most massive simulation to date of non-equilibrium
dynamics, carried out on the Janus~II custom-built supercomputer.Comment: Version accepted for publication in Communication Physics 10 pages, 9
figure
Variation of morphological descriptors for the evaluation of tomato germplasm and their stability across different growing conditions
[EN] Germplasm and breeding materials are usually characterized using morphological and agronomic descriptors,
which should have a high heritability. Despite the widespread use of tomato (Solanum lycopersicum) standardized
descriptors, little information exists on environmental effects on descriptor values and their heritability. We have
evaluated 12 tomato accessions from seven cultivar groups in three different environments (open-field conventional,
open-field organic, and greenhouse) and characterized them with 36 descriptors. A wide range of
variation was found for most descriptors, demonstrating their utility for describing tomato materials and their
diversity and relationships. The analysis of descriptors variation reveals that while for some descriptors with a
simple genetic control the accession effect accounts for 100% of the variation, for others like yield per plant only
10.83% of the variation observed is due to the accession effect. Although significant differences were found
among environments for most descriptors, including a much higher yield in the open-field conventional environment
than in the two others, the environmental effect was low for most traits. However, the genotypeĂ—environment
effect generally had an important contribution to the structure of variation for many descriptors,
and for three traits it had the highest contribution to the percentage of the sum of squares. As a result of
the variation structure, the heritability values are high (> 0.7) for only 10 descriptors, while for five is low
(< 0.3). Principal components analysis (PCA) reveals that projections in the PCA graph of a same accession
grown in different environments plot together in the same area of the PCA graph. Although cultivar groups are
generally clearly separated in the PCA graph, accessions from the same cultivar group in some cases are intermixed.
These results have important implications for detecting tomato duplicates and establishing core collections,
as well as for analyzing germplasm and breeding results, when using data sets containing data of
accessions grown in different environments.This work has been partially funded by the TRADITOM (Traditional tomato varieties and cultural practices: a case for agricultural diversification with impacto n food security and health of European population) and G2P-SOL (Linking genetic resources, genomes and phenotypes of Solanaceous crops) projects. These projects have received funding from the European Union's Horizon 2020 research and innovation programme under grant agreements No 634561 (TRADITOM) and No 677379 (G2P-SOL). Authors are grateful to Mr. Jonatan Cerdan for his technical help.Figás-Moreno, MDR.; Prohens Tomás, J.; Casanova-Calancha, C.; Fernández De CĂłrdova MartĂnez, PJ.; Soler Aleixandre, S. (2018). Variation of morphological descriptors for the evaluation of tomato germplasm and their stability across different growing conditions. Scientia Horticulturae. 238:107-115. https://doi.org/10.1016/j.scienta.2018.04.039S10711523
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