2,176 research outputs found
Copernicus observations of Betelgeuse and Antares
Copernicus observations of the M-supergiants, alpha Ori and alpha Sco, are presented. The MgII h and k resonance lines are strongly in emission in both stars. The k line is highly asymmetric in both stars but the h line is symmetric. Upper limits for several other resonance lines are given for alpha Ori. The possibility is explored that the k line asymmetry is caused by overlying resonance lines of MnI and FeI formed in the cool circumstellar gas shells around these stars. Observations of the MnI 4030-4033 A lines are used to show that circumstellar shell absorption is too weak to explain the asymmetry. It is suggested that the absorption occurs in a cool turbulent region between the base of the circumstellar shell and the top of the chromosphere
"Beans are Bullets" and "Of Course I Can!" Exhibiting War-Era Posters from the Collection of the National Agriculture Library
An exhibit of food and agriculture posters in the Special Collection of the National Agriculture Library will display posters from World Wars I and II side by side. What did these messages look like and how did they change over time? Public servants produced the earlier WWI posters to reflect "reason-why" approaches to mass communication. During WWII, the Advertising Council's business-minded admen produced posters with their techniques for modern advertising and mass persuasion. Poster text shortened, the tone lightened and images were more frequent and splashier. This collection of posters bears witness to the professionalization and rising influence of the advertising industry in the 1920s and 30s, and reveals the agendas of the creators and their assumptions about homefront populations. The posters raise questions about the sources and ambitions of government sponsored messages designed to encourage cooperation with war efforts and modify homefront behavior
Els alumnes de segon grau de formació professional fan pràctiques a les empreses
Abstract not availabl
Can pollen provision mitigate competition interactions between three phytoseiid predators of Tetranychus urticae under future climate change conditions?
Biological control can be severely disrupted by hot and dry environmental conditions associated with climate change. These conditions may alter the food web configuration of arthropod communities through their effects on species interactions. They could disrupt the competition between the phytoseiid predators Euseius stipulatus, Neoseiulus californicus, and Phytoseiulus persimilis, which are the key natural enemies of Tetranychus urticae in citrus in Spain. Because the provision of alternative food could compensate for such a situation, we studied in laboratory conditions whether pollen supply could modify competition among these predatory species under different climatic conditions. Our results show that access to high-quality pollen may enhance the performance of E. stipulatus and N. californicus. However, when the phytoseiids considered in our study were forced to compete, pollen provision had contrasting effects depending on the competing pair. Overall, climate change did not affect predation when pollen was available. Predation, though, was lower than expected except when the competing pair was P. persimilis and E. stipulatus. Therefore, pollen provision can partially mitigate the adverse effects of climate change on some of the biological parameters of the three main predators of T. urticae when competing in the system. This has important implications for the future success of biological pest control.Funding for open access charge: CRUE-Universitat Jaume IThe authors thank M. Piquer (UJI) and Arcadi Sanz (UJI) for technical assistance, J. Calvo (KOPPERT BS, Spain) for supplying N. californicus, M.V Ibáñez-Gual (UJI) for statistical advice, and C. Rodriguez-Saona for comments on an earlier version of the manuscript. PUB received a predoctoral grant from MCINN (EEBB-I-14-08555)
pWCET a Toolset for automatic Worst-Case Execution Time Analysis of Real-Time Embedded Programs
Experimental assessment of Textile Reinforced Sprayed Mortar strengthening system for brickwork wallettes
This work explores the feasibility of strengthening masonry with Textile Reinforced Mortar (TRM) by projecting it to save application time. Nineteen tests on masonry samples strengthened with TRM have been carried out to assess this new application method. Different mortars and fibre grids were considered for studying their influence and applicability with this new technique. Three points bending tests have been performed on the specimens to compare the flexural strength between cases with manually applied mortar (TRM) and sprayed application (TRSM) of the mortar layer. It was noticed that the strengthening mortar has a significant influence on the failure mode. Results show a remarkable (between 2 and 6 times more) productivity increase when using TRSM and a load-bearing capacity rise for the cases with larger grid spacing and projectable mortar when using TRSM instead of TRM. Greater ductility values were also observed for the TRSM cases in comparison with the analogue TRM cases (same grid and mortar). (C) 2013 Elsevier Ltd. All rights reserved.Peer ReviewedPostprint (author’s final draft
Datations Io-U du plus haut niveau marin du dernier interglaciaire sur la côte du Brésil : utilisation du 229Th comme traceur
Switcher-random-walks: a cognitive-inspired mechanism for network exploration
Semantic memory is the subsystem of human memory that stores knowledge of
concepts or meanings, as opposed to life specific experiences. The organization
of concepts within semantic memory can be understood as a semantic network,
where the concepts (nodes) are associated (linked) to others depending on
perceptions, similarities, etc. Lexical access is the complementary part of
this system and allows the retrieval of such organized knowledge. While
conceptual information is stored under certain underlying organization (and
thus gives rise to a specific topology), it is crucial to have an accurate
access to any of the information units, e.g. the concepts, for efficiently
retrieving semantic information for real-time needings. An example of an
information retrieval process occurs in verbal fluency tasks, and it is known
to involve two different mechanisms: -clustering-, or generating words within a
subcategory, and, when a subcategory is exhausted, -switching- to a new
subcategory. We extended this approach to random-walking on a network
(clustering) in combination to jumping (switching) to any node with certain
probability and derived its analytical expression based on Markov chains.
Results show that this dual mechanism contributes to optimize the exploration
of different network models in terms of the mean first passage time.
Additionally, this cognitive inspired dual mechanism opens a new framework to
better understand and evaluate exploration, propagation and transport phenomena
in other complex systems where switching-like phenomena are feasible.Comment: 9 pages, 3 figures. Accepted in "International Journal of
Bifurcations and Chaos": Special issue on "Modelling and Computation on
Complex Networks
Discrepancy Between Self-Report and School-Record Grade Point Average: Correlates With Psychosocial Outcomes Among African American Adolescents 1
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72176/1/j.1559-1816.2002.tb01421.x.pd
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