Stable Umbral Chromospheric Structures

Aims. To understand the morphology of the chromosphere in sunspot umbra. We investigate if the horizontal structures observed in the spectral core of the Ca II H line are ephemeral visuals caused by the shock dynamics of more stable structures, and examine their relationship with observables in the H-alpha line. Methods. Filtergrams in the core of the Ca II H and H-alpha lines as observed with the Swedish 1-m Solar Telescope are employed. We utilise a technique that creates composite images and tracks the flash propagation horizontally. Results. We find 0"15 wide horizontal structures, in all of the three target sunspots, for every flash where the seeing was moderate to good. Discrete dark structures are identified that are stable for at least two umbral flashes, as well as systems of structures that live for up to 24 minutes. We find cases of extremely extended structures with similar stability, with one such structure showing an extent of 5". Some of these structures have a correspondence in H-alpha but we were unable to find a one to one correspondence for every occurrence. If the dark streaks are formed at the same heights as umbral flashes then there are systems of structures with strong departures from the vertical for all three analysed sunspots. Conclusions. Long-lived Ca II H filamentary horizontal structures are a common and likely ever-present feature in the umbra of sunspots. If the magnetic field in the chromosphere of the umbra is indeed aligned with the structures, then the present theoretical understanding of the typical umbra needs to be revisited.Comment: Accepted to Astronomy and Astrophysics. Online material (Fig3.mov and Fig4.mov) will be available at A&

Cosmic microwave background and parametric resonance in reheating

The variation of the perturbative 3-curvature parameter, \zeta, is investigated in the period of reheating after inflation. The two-field model used has the inflaton, with an extra scalar field coupled to it, and non-linear effects of both fields are included as well as a slow decay mechanism into the hydrodynamic fluid of the radiation era. Changes in \zeta occur and persist into the succeeding cosmic eras to influence the generation of the cosmic microwave background fluctuations.Comment: 21 pages, 6 figures.Corrects misprinted formula and 2 number

Students’ engagement in school and creativity professed by students and assigned to teachers: A literature review

Este E-Book reúne um conjunto de investigações apresentadas no “I Congresso Internacional Envolvimento dos Alunos na Escola: Perspetivas da Psicologia e Educação” (ICIEAE), organizado no âmbito do “Projeto PTDC/CPE-CED/114362/2009 - Envolvimento dos Alunos na Escola: Diferenciação e Promoção” (EAE-DP), financiado pela Fundação para a Ciência e a Tecnologia (FCT).This article reviews the literature on the relation between creativity (as a personal and a contextual variable) and students’ engagement in school. In order to describe the state of art of student’s engagement in school and creativity, we prepared a narrative review. In general, literature shows a prevalence of studies relating creativity and giftedness; students with above average skills are, as a rule, characterized, among other criteria, by the presence of creativity and the existence of high motivation for learning. As a personal variable, creativity relates positively with self-concept and academic performance, appearing as an aspect worth encouraging in the student. Moreover, studies on the impact of the learning environments on student’s performance also suggest a positive relationship between the classroom climate and academic outcomes. Although studies on the relationship between creativity and the students’ behavior appear inconsistent, the teacher’s creativity, applied to the teaching-learning process, and perceived by the student, appears related to school satisfaction and academic performance. This brief review highlights the value of including creativity in teaching practices, drawing attention to the lack of studies and the need to develop research, both relational and quasi-experimental, on the relationship between creativity and students’ engagement in school and its effects

New methodologies for the promotion of Geological Heritage using multimedia technology, 3D and augmented reality.

[Excerpt] The Internet and several hardware and software options that are currently available are very efficient ways for the promotion of geoparks, geoheritage and geosciences. The aim of this paper is to present a new and interactive way of gathering data into a website, based on several new web and photogrammetric technologies, applied to the Terras de Cavaleiros Global Geopark (Portugal). [...]info:eu-repo/semantics/publishedVersio

Methodologies to represent and promote the geoheritage using unmanned aerial vehicles, multimedia technologies, and augmented reality

Promoting geoheritage using the Internet materializes mainly through the use of maps, posters, informational murals, or websites. This information is usually detailed and visually appealing. However, in most cases, there is little interactivity and a limited or complete lack of contextualization within the geographical space. The main objective of this work was to integrate information collected with unmanned aerial vehicles, georeferenced information processed in geographical information systems, photogram- metry techniques, and multimedia technologies to promote a better computer visualization of geoheritage. A working website was built based on panoramic photography, three-dimensional representation of the terrain, and multimedia information, in order to provide a pleasant way of promoting and interacting with field geology by using the Internet. The navigation through the information is based on 360° spherical panoramic images that are fully oriented and georeferenced. Their movement can be perfectly synchronized with the viewing of the landscape by using motion sensors found on portable devices (tablets or smartphones) such as GPS, accelerometers, gyroscopes, or compasses. These images can include the access to multimedia elements such as websites, videos, images, sounds, interpretation models, text, or interactive 3D terrain models, working as an excellent support base for the provision of an augmented reality experience. If used in the field, this technical implementation can act as an interactive guide for the interpretation of the landscape. This type of content can be accessed online from locations with a network signal or can be obtained in advance for offline use.This work received financial support from Capes - Higher Education Personnel Improvement Coordination for the granted in Brazil between 2013 and 2014 and abroad in 2015. This work was co-funded by the European Union through the European Regional Development Fund, based on COMPETE 2020 (Programa Operacional da Competitividade e Internacionalização), project ICT (UID/GEO/04683/2013) with reference POCI-01-0145-FEDER-007690 and national funds provided by Foundation of Science and Technology (FCT)

Can geosites be restored? The example of the Alto Vez geosite (Peneda Mountain, Portugal)

One of the most important tasks in geoheritage management is the conservation of the geosite values, protecting them from natural or human induced degradation. In some cases, degradation still occurs even with the existence of geoconservation initiatives. Normally, the loss of geodiversity features is irreversible and protection measures are only applied in order to try to stop further damage. However, should this be imperative to all types of geosites? This question emerged with the case of the restoration of the Alto Vez geosite in the Peneda Mountain, one of the most remarkable fields of glacial erratic boulders in Portugal. Besides the erratic granite boulders, other relevant glacial features occur such as an U-shaped valley and moraines, justifying the inclusion of this site as one of the most important geosites in the Portuguese geoheritage inventory. Despite its scientific relevance, it is located just outside the contiguous Peneda-Gerês National Park, the most important protected area in Portugal. This national park was founded in 1971 and its limits were defined before the scientific discovery of these relevant glacial features. In 2012, a horseracing track was constructed in the geosite by the local village administration, with the removal of erratic boulders from their original place, affecting the natural landscape and the geosite’s integrity. After a claim made by a citizen, legal and administrative actions made by the Portuguese Institute of Nature Conservation and Forests and by the municipal authorities, have resulted in the closure of the racing track, an assessment of the degradation and definition of a strategy to reduce the damages. Under our supervision, a restoration plan was conducted in 2017. Aerial photos captured by unmanned aerial vehicles were used, together with dGPS and GIS procedures. The initial topography was restored using earthmoving machinery and the buried erratic boulders were identified and carefully relocated to their original position. A management plan of the geosite is being produced in order to protect it more efficiently through a statutory designation and to promote its tourism and educational uses. This case-study shows that a well-informed society is essential to help authorities to protect geoheritage and that a geosite restoration is possible when the main geodiversity features are not yet fully destroyed

Astenopia Digital: Estudo do Grupo Português de Ergoftalmologia

INTRODUCTION: Given the increasing use of electronic devices, and the increasing number of complaints with its use, we intend to evaluate the prevalence of manifestations of dry eye and ocular fatigue in a population of individuals, who use the computer daily to perform all their professional tasks, as well as to correlate these complaints with the number of hours of digital use as well as their possible improvement with behavioural measures and use of tear drops. MATERIAL AND METHODS: A total of 77 individuals (154 eyes) were evaluated on two separate days with a 1-month interval. They completed two questionnaires: OSDI and PEG Eye Fatigue. An objective ocular surface assessment was performed: Schirmer test without anesthetic, DR-1a Dry Eye Monitor™, hyperemia evaluation, lacrimal break up, presence of keratitis and lesions in the conjunctiva, as well as near accommodation point and near convergence point. After the first evaluation, the subjects were divided into two groups: group A ( 2 hours of computer working). Some environmental measures to reduce complaints and recommendation of use of artificial tears were explained to the latter. RESULTS: There was a statistically significant difference in the majority of the parameters evaluated in the group B, in relation to the morning period (group A) - tear film (p = 0.032), hyperemia (p < 0.001), BUT (p < 0.001), keratitis (p < 0.001), conjunctival lesion (p = 0.002) and accommodation point (p < 0.001). In the evaluation - one month later - there were no statistically significant differences in any of the parameters analysed in the group A, and in group B there was a decrease in most parameters at the end of that period - Schirmer test (p = 0.005), lacrimal film (p = 0.022), keratitis (p < 0.001), conjunctival lesion (p = 0.005) and fatigue score (p < 0.001). DISCUSSION: It was thus possible to show the appearance of ocular fatigue and ocular surface changes with prolonged use of computers (> 2 hours) as well as a significant improvement in symptomatology (subjective assessment) as well as of ocular surface changes (objective evaluation) with the implementation of postural measures, regular breaks and use of lubricants. This is the first study, to the best of our knowledge, of digital asthenopia in which, in addition to the subjective evaluation, the presence of ocular surface modifications (objective assessment) were evaluated and the respective improvement with the aforementioned ergophthalmological measures were evaluated. CONCLUSION: This survey highlights the increased overall level of awareness that we need to have to face the rapid and wide-scale changes driven by the emergence of digital technology and, more particularly, its impact on user's vision and posture. We concluded that the longer we use the electronic devices (more than two hours) the more severe the complaints and rates of ocular surface changes are. Environmental and ocular strategies can attenuate or even eliminate the discomfort caused by this syndrome, and increase professional performance and quality of life.info:eu-repo/semantics/publishedVersio

Avaliação da capacidade de adesão de células de biofilmes de Candida após tratamento com nanopartículas de prata

O objetivo deste estudo foi investigar a capacidade de adesão a células epiteliais humanas e a superfície de poliestireno de leveduras viáveis recuperadas de biofilmes de Candida albicans e Candida glabrata tratados com nanopartículas de prata (NP). Métodos: Biofilmes de Candida (48 hrs) foram formados em placas de microtitulação de 6 poços e tratados por 24 horas com NP (5 nm) nas concentrações de 13,5 e 54 mg/L. Suspensões de células de Candida (107 células viáveis/mL em RPMI 1640) provenientes dos biofilmes tratados com NP foram adicionadas a monocamadas de células HeLa e a poços vazios de placas de microtitulação de 24 poços (para estudar adesão a poliestireno). Após 2 horas de contato, a adesão das leveduras foi determinada usando a coloração com violeta cristal. Resultados: A capacidade de adesão de leveduras viáveis a células HeLa e a superfícies de poliestireno foi significativamente reduzida, e esta redução foi maior quando os biofilmes foram pré-tratados com NP na concentração de 54 mg/L. Ainda, a quantidade de leveduras aderidas das duas cepas diferiu de acordo com o substrato (células epiteliais e superfície de poliestireno). Conclusão: NP podem induzir modificações em leveduras viáveis, as quais podem diminuir a disseminação de infecções por Candida, principalmente em pacientes imunocomprometidos