1,148 research outputs found

    Field location and player roles as constraints on emergent 1-vs-1 interpersonal patterns of play in football

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    This study examined effects of player roles on interpersonal patterns of coordination that sustain decision-making in 1-vs-1 sub-phases of football in different field locations near the goal (left-, middle- and right zone). Participants were fifteen U-16 yrs players from a local competitive amateur team. To measure interpersonal patterns of coordination in the 1-vs-1 dyads we recorded: (i) the relative distance value between each attacker and defender to the centre of the goal, and (ii), the relative angle between the centre of the goal, each defender and attacker. Results revealed how variations in field locations near the goal (left-, middle- and right-zones) constrained the relative distance and relative angle values that emerged between them and the goal. It reveals that relative position of the goal is a key informational variable that sustained participants’ behaviours for dribbling and shooting. Higher values of relative distance and angle were observed in the middle zone, compared to other zones. Players’ roles also constitute a constraint on the interpersonal coordination for dribbling and shooting. Additionally, it seems that players’ foot preference constrains the dynamics of interpersonal patterns of coordination between participants, especially in left and right zones. The findings suggest that to increase participants’ opportunities for action, coaches should account with field positions, players’ roles and preference foot

    Review of a Small-scale Pelagic Longline Fishery off Northeastern Brazil

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    The annual catches of four small longliners operating off northeast Brazil from 1983 to 1997 were examined across different areas and locations. The total catch comprised tunas (30%), sharks (54%), billfishes (12%), and other fish species (4%). Fishing strategy and annual composition of catches showed large spatial and temporal variabilities with the dominant catches alternating among yellowfin tuna, Thunnus albacares; gray sharks, Carcharhinus spp.; and blue shark, Prionace glauca. Catches of blue and gray sharks showed a significant interaction among seamounts, with gray sharks occurring in maximum abundance around those seamounts that had relatively deep summits and low-sloping depth profiles. Results are discussed in terms of the various factors that may have influenced distribution of effort

    Reacção de rubino

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    Attacking profiles of the best ranked teams from elite futsal leagues

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    This study aimed to (i) explore the discriminatory power of the task-related variables and the context in establishing differences in the elite futsal leagues of Portugal, Spain, and Russia and (ii) understand how these variables vary according to the match outcome. Methodological issues concerning efficiency (goals and shots), offensive organisation (positional attack, counterattack, set pieces, or 5vs4+Goalkeeper), 1st goal scored during matches (home or away team), match type (balanced or unbalanced), and match outcome (winner, loser, or drawer) were discussed. Archival data were obtained from the 2017-2018 season of Portuguese, Spanish, and Russian professional futsal leagues for all play-off matches. Crosstabs analysis was conducted to establish the significance relationship between the elite futsal leagues and the situational variables. Afterward, discriminant analysis was used to identify the task-related variables that maximise mean differences between different league teams for defining offensive profile, and the variations found when the condition of the winner, loser, or drawer is taken into account. The results allowed to understand that the Portuguese and Russian teams used the positional attacks more, and less the counterattacks and set pieces than the Spaniards, who present a more balanced offensive profile. Overall, winners were better discriminated by goals scored, whereas 5vs4+Goalkeeper strategy discriminated loser teams. Coaches should be aware of these different offensive profiles in order to increase control over the match planning and decrease predictability against opposing teams.info:eu-repo/semantics/publishedVersio

    Magnetotelluric data processing: a case study

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    Magnetotelluric (MT) data collected simultaneously at one or more sites may be processed by a number of different methods. Such methods attempt to remove or suppress the effect of noise on the data channels. The desired results are accurate, unbiased and repeatable estimates of the impedance tensor as a function of frequency and location. In this study we perform an investigation of the analysis of an MT data set sampled at 5 s. Both single-site (SS) and remote-reference (RR) techniques are employed to estimate the impedance tensor Z. Two biased SS estimates of Z are used to compare the performance of five coherence­ based acceptance criteria. It is demonstrated that the RR predicted coherence between local fields can be used for selecting data windows, and provides a necessary assessment of the reliability of a given RR estimate. It is demonstrated that the variance of an RR estimate depends strongly on the local signal-to-noise ratios (as monitored by the local predicted coherence) and depends weakly on the number of data windows, as long as coherences are above a moderate threshold. Although, for our data, an estimate of Z obtained using a remote electric field is grossly inaccurate, its associated predicted coherence is as efficient in selecting low-noise-level data windows as its counterpart obtained using a remote magnetic field. The relation between SS and RR predicted coherences, the latter estimated using both electric and magnetic fields, is investigated. A hybrid selection technique that uses a remote electric field is suggested

    Implementation in real time of a fast least squares on a Digital Signal Processor

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    This paper presents a real-time implementation of a fast least-squares algorithm (FLS), for the linear prediction of sinusoidal signais in noise, and analyzes the results . The FLS algorithm has two divergence modes . We propose two simple techniques which provide long-term stability, and study their effects on the performance of the algorithm . The experimental method is discussed and results are presented in the form of oscilloscope curves .On présente un algorithme MCR pour la prédiction linéaire de signaux sinusoïdaux bruités. Ce type d'algorithme présente fondamentalement deux modes de divergence. On propose deux méthodes simples pour le rendre stable à long terme et on étudie l'effet de ces méthodes sur les performance

    Bionomia de Mantodea (Insecta) em Laboratório. I – Parastagmatoptera Unipunctata (Burm., 1838). Mantidae-Vatinae

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    A criação dos insetos da ordem Mantodea vem sendo objeto de pesquisas de um dos autores (Travassos Filho), desde 1942, já tendo publicado algumas observações (7, 8, 9, 10 e 11). Embora até o presente tivessem sido criadas muitas espécies, com os respectivos dados bionômico devidamente registrados, a oportunidade para uma analise completa e inicio de publicação dessas observações só surgiu recente[1]mente, com a vinda para o Departamento de Zoologia, da biologista co-autora deste artigo (Heitzmann), que vem se dedicando ao estudo morfológico dos mantodeos adultos e suas formas evolutivas, particularmente as exuvias, com objetivo de verificação dos caracteres que possam servir à sistemática desses curiosos insetos (4 e 5)

    Preliminary Results of Circle and J-Style Hook Comparisons in the Brazilian Pelagic Longline Fishery

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    Preliminary studies in western North Atlantic pelagic longline fisheries indicate that a change in terminal gear from J-style hooks to circle hooks may reduce bycatch mortality. However, such studies have not examined the impact of this change in the equatorial fishery. Catch composition, catch rates, hooking location, and condition at haulback were monitored during 26 sets in the commercial longline fishery operating in the western equatorial South Atlantic where circle (size 18/0, non-offset) and J-style (size 9/0 and 10/0, 10° offset) hooks were deployed in an alternating fashion. Catch rates for yellowfin tuna, swordfish, and a composite “all fishes” category were significantly (P \u3c 0.05) higher for circle hooks. Bigeye tuna, swordfish, sailfish, and yellowfin tuna were hooked significantly more often externally than internally. Yellowfin tuna were over eight times more likely to be hooked in the mouth with circle hooks than with J-style hooks. Bigeye tuna and sailfish showed significantly higher rates of survival at haulback with circle hooks. The results suggest that the use of size 18/0 non-offset circle hooks in the equatorial pelagic longline fishery may increase the survival of bycatch species at haulback with minimal detrimental effects on the catches of target species

    Dengue epidemic in Belém, Pará, Brazil, 1996-97.

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    We describe clinical and epidemiologic findings during the first epidemic of dengue fever in Belém, Pará State, Brazil, in 1996-97. Of 40,237 serum samples, 17,440 (43%) were positive for dengue by virus isolation or serologic testing. No hemorrhagic cases or deaths were reported. Mycobacterium tuberculosi
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