9,063 research outputs found
Physical processes leading to surface inhomogeneities: the case of rotation
In this lecture I discuss the bulk surface heterogeneity of rotating stars,
namely gravity darkening. I especially detail the derivation of the omega-model
of Espinosa Lara & Rieutord (2011), which gives the gravity darkening in
early-type stars. I also discuss the problem of deriving gravity darkening in
stars owning a convective envelope and in those that are members of a binary
system.Comment: 23 pages, 11 figure, Lecture given to the school on the cartography
of the Sun and the stars (May 2014 in Besan\c{c}on), to appear in LNP, Neiner
and Rozelot edts V2: typos correcte
Efeito de genótipos de sorgo sobre o predador Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae) alimentado com Schizaphis graminum (Rondani) (Hemiptera: Aphididae).
O trabalho objetivou avaliar o efeito indireto da resistência de genótipos de soro sobre o predador Chrysoperla externa (Hagen) usando o pulgão Schizaphis graminum (Rondani) como presa. Os genótipos usados no estudo foram: GR 11111 e TX 430 x GR 111 (resistentes), GB 3B (moderadamente resistente) e BR 007B (suscetível). Larvas recém-eclodidas foram confinadas individualmente em recipientes de vidro e alimentadas com S. graminum, criados separadamente em cada um dos quatro genótipos. após a emergência, os adultos obtidos de cada tratamento foram sexados e agrupados aos casais, colocados em gaiolas contendo dieta à base de levedo de cerveja e mel. Os insetos foram observados diariamente da fase jovem até o período de 60 dias após a emergência do adulto. Genótipos com maior grau de resistência proporcionaram maior consumo de pulgões pelo predador, porém menor peso a este. Quando os pulgões foram criados no genótipo resistente GR 11111, o peso das larvas, sobrevivência da pré-pupa e longevidade da fêmea do predador foram inferiores. As associações positivas observadas entre o predador, C. externa, e o genótipo resistente, TX 430 x GR 111, e entre o predador e o genótipo moderadamente resistente GB 3B, evidenciaram a possibilidade de integração entre os dois métodos de controle: resistência de plantas e controle biológico
Influência da presença do predador Chrysoperla externa em diferentes níveis de infestação de Schizaphis graminum em genótipos de sorgo.
Biology of immature Chrysoperla externa predator fed with Schizaphis graminum aphids reared on resistant, moderately resistant and susceptible sorghum genotypes.
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Flipping the Tortilla: Social-ecological innovations and traditional ecological knowledge for more sustainable agri-food systems in Spain
The conventional dominant global agri-food system is a main driver in the Anthropocene: food production entails profound global environmental changes from greenhouse gas emissions to biodiversity loss, and shifting diets further impact planetary and human health. Innovative approaches are needed to shift towards more sustainable, equitable and healthy agri-food systems. Building on the increasing recognition of the relevance of traditional agroecological knowledge (TAeK) in sustainable food systems, this paper aims to describe innovative agri-food initiatives and explore how the use and valorization of TAeK may transform conventional agri-food systems. It employs a case-study approach in Spain, where we conducted semi-structured interviews with 12 representatives of alternative agri-food initiatives. We found that, to promote sustainable agri-food systems, TAeK has to span from farm-to-fork. Innovative agroecological practices and knowledge help to safeguard biocultural diversity, while gastronomic knowledge among consumers on how to process and prepare local varieties and species is crucial for the implementation of shorter value chains. We discuss how TAeK enhances the success of conventional systems of innovation, challenging dominant epistemological frameworks. By scaling deep (changing values), scaling out (dissemination, reproduction) and scaling up (changing institutions), the agri-food initiatives may act on leverage points to enable broader transformation of the Spanish agri-food system
Evidence of ongoing radial migration in NGC 6754: Azimuthal variations of the gas properties
Understanding the nature of spiral structure in disk galaxies is one of the
main, and still unsolved questions in galactic astronomy. However, theoretical
works are proposing new testable predictions whose detection is becoming
feasible with recent development in instrumentation. In particular, streaming
motions along spiral arms are expected to induce azimuthal variations in the
chemical composition of a galaxy at a given galactic radius. In this letter we
analyse the gas content in NGC 6754 with VLT/MUSE data to characterise its 2D
chemical composition and H line-of-sight velocity distribution. We find
that the trailing (leading) edge of the NGC 6754 spiral arms show signatures of
tangentially-slower, radially-outward (tangentially-faster, radially-inward)
streaming motions of metal-rich (poor) gas over a large range of radii. These
results show direct evidence of gas radial migration for the first time. We
compare our results with the gas behaviour in a -body disk simulation
showing spiral morphological features rotating with a similar speed as the gas
at every radius, in good agreement with the observed trend. This indicates that
the spiral arm features in NGC 6754 may be transient and rotate similarly as
the gas does at a large range of radii.Comment: 8 pages, 4 figures, accepted for publication in ApJL 2016 September
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Effects of sorghum genotypes resistance to Schizaphis graminum (Rondani) on Chrysoperla externa (Hagen) fecundity.
Correlation of the Indoor Air Quality Santriwati Dormitory with Acute Respiratory Infection at Raudhatul Ulum Islamic Boarding Schools and Al-ittifaqiah Islamic Boarding Schools in Ogan Ilir on 2015
Background: The high number of acute respiratory infection found in two islamic boarding schools specifically at Raudhatul Ulum Islamic Boarding Schools are 178 cases and 231 cases at Al-Ittifaqiah. Method: It was an observational research using cross-sectional design. Research sites at Raudhatul Ulum Islamic Boarding Schools and Al-Ittifaqiah Islamic Boarding Schools in Ogan Ilir. The population research was all santriwati both Islamic boarding schools that total sample 72 santriwati. The dependent variable in this study was santriwati incidence of respiratory infection, the independent variable was the physical quality of the air (temperature, lighting, humidity, rate of ventilation), the quality of biological air (number of bacterial air), residential density, sanitize behavior, and the behavior of openning window.The sample collection technique namely random sampling with the methods of sampling stratified. Data would be analyzed using chi square test. Result: The research result showed that there is significant correlation between temperature p= 0,013, residential density p= 0,003, sanitize behavior p= 0,001, and the behavior of opening a window p= 0,012 on the acute respiratory infection. There is no significant relationship in lighting p= 0,401, humidity p= 0,170, ventilation rate p= 0,489, and the germ air p= 0,170 as the acute respiratory infection. Conclusion: This research concluded that temperatur, residential density, sanitize behavior, and the behavior of opening window have significant correlation
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