Search results for "Iris"
showing 10 items of 258 documents
Enhancement of the Multipactor Threshold Inside Nonrectangular Iris
2018
Multipactor breakdown is studied inside the capacitive iris of a rectangular waveguide with a skewed slot along its longitudinal cross section. Both the iris length and height are assumed to be small compared to the electromagnetic wavelength. Therefore, the quasi-static approximation is applied so as to describe the RF field distribution inside the iris gap, whereas a 2-D model is used to analyze the electron motion. The peculiarities of RF field structure are studied using the conformal mapping approach, which shows that the electric field lines can be approximated by circular arcs when the iris length is much larger than its height. The electron motion inside the iris gap is analyzed usi…
Impulsive coronal heating from large-scale magnetic rearrangements: from IRIS to SDO/AIA
2019
The Interface Region Imaging Spectrograph (IRIS) has observed bright spots at the transition region footpoints associated with heating in the overlying loops, as observed by coronal imagers. Some of these brightenings show significant blueshifts in the Si iv line at 1402.77 A (logT[K] = 4.9). Such blueshifts cannot be reproduced by coronal loop models assuming heating by thermal conduction only, but are consistent with electron beam heating, highlighting for the first time the possible importance of non-thermal electrons in the heating of non-flaring active regions. Here we report on the coronal counterparts of these brightenings observed in the hot channels of the Atmospheric Imaging Assem…
Floral scent in Iris planifolia (Iridaceae) suggests food reward
2018
Iris species can adopt different pollination strategies to attract their pollinators, generalized shelter-mimicking, specialized deceptive sexual-mimicking or food-rewarding. As attractive stimuli, Iris flowers may use their colours, large-size, symmetry, and volatile organic compounds (VOCs). However, relatively few studies in- vestigated Iris floral olfactory cues in the context of plant-visitor/pollinator interactions. In the present study we combined the identification of the floral volatiles of the nectariferous I. planifolia with insects visiting its flowers to gather data on its biology. Floral volatiles were collected in the natural environment by dynamic headspace and analysed by g…
Does iris(in) bring bad news or good news?
2017
Irisin, a novel myokine produced in response to physical activity, promotes white-to-brown fat transdifferentiation. The name irisin referred to the ancient Greek goddess Iris, the messenger who delivered (bad) news from the gods. In mice, it has been demonstrated that irisin plays a key role in metabolic regulation, energy expenditure and glucose homeostasis. New findings from various studies carried out in both animals and humans suggest that irisin might also have other favorable effects, such as increasing bone cortical mass, preventing hepatic lipid accumulation, and improving cognitive functions, thus mediating many exercise-induced health benefits. However, data on the role and funct…
Pathophysiology of non alcoholic fatty liver disease
2016
The physiopathology of fatty liver and metabolic syndrome are influenced by diet, life style and inflammation, which have a major impact on the severity of the clinicopathologic outcome of non-alcoholic fatty liver disease. A short comprehensive review is provided on current knowledge of the pathophysiological interplay among major circulating effectors/mediators of fatty liver, such as circulating lipids, mediators released by adipose, muscle and liver tissues and pancreatic and gut hormones in relation to diet, exercise and inflammation.
Physical Activity and Brain Health.
2019
Physical activity (PA) has been central in the life of our species for most of its history, and thus shaped our physiology during evolution. However, only recently the health consequences of a sedentary lifestyle, and of highly energetic diets, are becoming clear. It has been also acknowledged that lifestyle and diet can induce epigenetic modifications which modify chromatin structure and gene expression, thus causing even heritable metabolic outcomes. Many studies have shown that PA can reverse at least some of the unwanted effects of sedentary lifestyle, and can also contribute in delaying brain aging and degenerative pathologies such as Alzheimer’s Disease, diabetes, and multiple s…
‘Drawing’ conclusions : Irish primary school children’s understanding of physical education and physical activity opportunities outside of school
2017
This study explores the relationship between primary school physical education and physical activity as sites for the practice of physical activity of Irish primary school children. Understanding how children make connections between physical activity sites is important in shaping physical education experiences that promote lifelong participation. Children’s (aged 8–11) awareness, knowledge, and understanding of physical activity and physical education were examined using participatory methods of ‘draw and write’ ( n = 135) and focus group interviews ( n = 34). In Phase 1, data collection focused on physical activity, while Phase 2 focused on physical education and connections between phys…
Minority Languages and Markets
2018
This chapter explores how minority languages figure in economic development and are invested with values of expertise, distinction and authenticity. Drawing on previous research, including the authors’ own studies on minority and indigenous language practices and discourses in peripheral, multilingual Irish and Sami sites, the chapter discusses the changing and expanding role of minority languages in some key economic domains: advertising and marketing, tourism, the media and job markets. It reflects on the conditions and consequences of economic processes for the exchange value of minority languages in changing markets.
DE PRESSUPOSTOS SOBRE O CONHECIMENTO E A APRENDIZAGEM À PRÁXIS NA FORMAÇÃO DO TRADUTOR
2016
Este artigo discute o problema da ausência de programas acadêmicos de qualificação para professores de tradução que têm de recorrer às suas próprias intuições e à abordagem pedagógica popular. Objetiva identificar os entendimentos subjacentes da natureza do conhecimento e da aprendizagem que estão por trás da tradicional prática de ensino do “Quem quer vai fazer a primeira sentença?”, bem como das abordagens didáticas alternativas. Embora existam algumas publicações inspiradoras e motivadoras sobre metodologias inovadoras de ensino centradas no aluno, estas ainda carecem de discussões sobre a epistemologia pedagógica ou quaisquer princípios gerais ou teoria da educação. A principal tese pro…
Sublimation of icy aggregates in the coma of comet 67P/Churyumov–Gerasimenko detected with the OSIRIS cameras on board Rosetta
2016
Beginning in 2014 March, the OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) cameras began capturing images of the nucleus and coma (gas and dust) of comet 67P/Churyumov¿Gerasimenko using both the wide angle camera (WAC) and the narrow angle camera (NAC). The many observations taken since July of 2014 have been used to study the morphology, location, and temporal variation of the comet's dust jets. We analysed the dust monitoring observations shortly after the southern vernal equinox on 2015 May 30 and 31 with the WAC at the heliocentric distance Rh = 1.53 AU, where it is possible to observe that the jet rotates with the nucleus. We found that the decline of brightness a…