How and why do Soccer Coaches use Small-Sided Games in the Training Process?

Purpose. The small-sided games (SSGs) allow to work in specificity, in accordance with the characteristics of the soccer game, the physical, technical, tactical, and psychological aspects. This study intends to understand how and why coaches use the SSGs in the training process. Methods. For this purpose, we applied a semi-structured interview. Two coaches were interviewed owing to their vast experience in high-performance training and youth training. The analysis was carried out through content analysis. We used categorization to group data with common characteristics. The category system was defined later. Results. The results demonstrate that SSGs are an integral part of the training process, allowing work in the physical, technical, and tactical aspects. The coaches interviewed argue that SSGs are an important work strategy for the articulation of the players in the sector and inter-sector of the team, on the basis of the tactical principles that they see reproduced in the competition. Conclusions. According to the interviewed coaches, SSGs are relevant as they may develop both tactical principles and physical capabilities. Applying such games during all the season allows to establish a direct relationship with specific moments that occur in official competitions.info:eu-repo/semantics/publishedVersio

Os Conflitos em Torno de uma Ferrovia de Escoamento de Minérios na Amazônia Oriental: Paradoxos da Sustentabilidade

A eclosão de conflitos sociais como manifestação de insatisfação de comunidades em áreas sob influência da mineração e transporte de minérios é um fenômeno recorrente nas últimas décadas, apesar dos esforços para diminuir os impactos socioambientais desta atividade, à luz dos novos valores da sustentabilidade. Porém, esses conflitos permanecem configurando-se um paradoxo. A metodolodia do estudo consistiu na análise de uma amostra de 69 conflitos sociais relacionados com a operação de uma ferrovia de transporte de minério com extensão de 900 km. Foram aplicadas teorias sobre conflitos ligados à atividade minerária na complexa relação entre a operação de uma ferrovia e as comunidades no seu entorno. Os resultados apontam que os conflitos estudados podem ser evitados e todos os stakeholders devem ser envolvidos na sua solução. Assim, mostram a necessidade de novos arranjos institucionais que favoreçam o diálogo efetivo, a construção de consensos e o planejamento de ações integradas

revista de Ciências da Arte

Organizando-se agora no formato de número duplo, de modo a comportar dois números por ano, a revista digital Convocarte – Revista de Ciências da Arte mantém o mesmo propósito de promover o debate e edição de questões artísticas no espaço universitário, mantendo as coordenadas dominantes: convocar um número de especialistas em torno de um tema do mundo das artes, integrar trabalhos relevantes desenvolvidos nas fases curriculares e de projecto em mestrados e doutoramentos, sobretudo da FBAUL, e publicar trabalhos desenvolvidos em linhas de investigação do CIEBA. Assim, embora de funcionamento afecto à área científica de Ciências da Arte e do Património a Convocarte está aberta a outras especialidades interessadas em contribuir para a reflexão sobre as artes em geral, incorporando ensaios de predomínio teórico enraizado nos mais predominantes modos de discurso sobre arte, tais como História da arte, Crítica de Arte, Estética, Teorias da Arte ou Curadoria. (...) O nº2 organizou-se em torno de uma homenagem a uma figura importante das teorias da arte em Portugal, estratégia que Convocarte procurará manter nos próximos números. A intenção será deixar estudos sistematizados, entre o depoimento ou o ensaio, a memória e a reflexão, que estudem figuras marcantes da cultura portuguesa. (...) Neste número essa pasta foi dedicada a Rui Mário Gonçalves. Os textos são o resultado de uma sessão especial alargada a 2 de Maio no âmbito dos 2ºs Encontros com Críticos de Arte, com organização e coordenação de Fernando Rosa Dias, Cristina Tavares e Viviane Soares Silva, e decorridos ao longo das segundas do mês de Maio de 2016 na FBAUL (http://convocarte.belasartes.ulisboa.pt/index.php/2016/04/29/2o-encontros-com-criticos-de-arte/#more-325). A partir destes trabalhos reuniu-se um conjunto de estudos em torno de Rui Mário Gonçalves, com depoimentos e estudos sobre as mais diferentes facetas desta importante figura da cultura portuguesa: crítico de arte, historiador de arte, curador artístico, pedagogo e professor, político e activista, etc. A Convocarte orgulha-se de publicar os textos dessas comunicações, acrescentado de outros estudos, agradecendo a todos os colaboradores deste evento, que consideramos uma pasta que adianta contributos dando continuidade a estudos no catálogo de homenagem e no âmbito de apresentação da colecção do crítico de arte na SNBA, realizada pouco antes na SNBA.info:eu-repo/semantics/publishedVersio

Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file

A search for ultra-high-energy photons at the Pierre Auger Observatory exploiting air-shower universality

The Pierre Auger Observatory is the most sensitive detector to primary photons with energies above ∼0.2 EeV. It measures extensive air showers using a hybrid technique that combines a fluorescence detector (FD) with a ground array of particle detectors (SD). The signatures of a photon-induced air shower are a larger atmospheric depth at the shower maximum (X$_{max}$) and a steeper lateral distribution function, along with a lower number of muons with respect to the bulk of hadron-induced background. Using observables measured by the FD and SD, three photon searches in different energy bands are performed. In particular, between threshold energies of 1-10 EeV, a new analysis technique has been developed by combining the FD-based measurement of X$_{max}$ with the SD signal through a parameter related to its muon content, derived from the universality of the air showers. This technique has led to a better photon/hadron separation and, consequently, to a higher search sensitivity, resulting in a tighter upper limit than before. The outcome of this new analysis is presented here, along with previous results in the energy ranges below 1 EeV and above 10 EeV. From the data collected by the Pierre Auger Observatory in about 15 years of operation, the most stringent constraints on the fraction of photons in the cosmic flux are set over almost three decades in energy

Study on multi-ELVES in the Pierre Auger Observatory

Since 2013, the four sites of the Fluorescence Detector (FD) of the Pierre Auger Observatory record ELVES with a dedicated trigger. These UV light emissions are correlated to distant lightning strikes. The length of recorded traces has been increased from 100 μs (2013), to 300 μs (2014-16), to 900 μs (2017-present), to progressively extend the observation of the light emission towards the vertical of the causative lightning and beyond. A large fraction of the observed events shows double ELVES within the time window, and, in some cases, even more complex structures are observed. The nature of the multi-ELVES is not completely understood but may be related to the different types of lightning in which they are originated. For example, it is known that Narrow Bipolar Events can produce double ELVES, and Energetic In-cloud Pulses, occurring between the main negative and upper positive charge layer of clouds, can induce double and even quadruple ELVES in the ionosphere. This report shows the seasonal and daily dependence of the time gap, amplitude ratio, and correlation between the pulse widths of the peaks in a sample of 1000+ multi-ELVES events recorded during the period 2014-20. The events have been compared with data from other satellite and ground-based sensing devices to study the correlation of their properties with lightning observables such as altitude and polarity