1,040 research outputs found
Dynamics of a map with power-law tail
We analyze a one-dimensional piecewise continuous discrete model proposed
originally in studies on population ecology. The map is composed of a linear
part and a power-law decreasing piece, and has three parameters. The system
presents both regular and chaotic behavior. We study numerically and, in part,
analytically different bifurcation structures. Particularly interesting is the
description of the abrupt transition order-to-chaos mediated by an attractor
made of an infinite number of limit cycles with only a finite number of
different periods. It is shown that the power-law piece in the map is at the
origin of this type of bifurcation. The system exhibits interior crises and
crisis-induced intermittency.Comment: 28 pages, 17 figure
"I don't know": a usage-based approach to familiar collocations in non-fluent aphasia
Background: Familiar collocations (e.g., “it’s alright”) are an important part of everyday conversation. Such word combinations are often retained in speakers with Broca’s aphasia. However, only few investigations have studied the forms and functions of familiar collocations available to speakers with Broca’s aphasia. //
Aims: We first apply a frequency-based perspective to word combinations produced by speakers with Broca’s aphasia and their conversation partners (CPs), and compare the frequency characteristics of word combinations in dyadic and non-dyadic speech. Second, we investigate the conversational functions of one prominent familiar collocation, “I don’t know” (IDK). //
Methods & Procedures: In the first analysis, speech samples from interactions of nine dyads (each a speaker with Broca’s aphasia and their CP) were examined. Non-dyadic samples were selected from 39 speakers with Broca’s aphasia from AphasiaBank (MacWhinney et al., 2011). The Frequency in Language Analysis Tool (FLAT; Zimmerer & Wibrow, 2015) was used to estimate collocation strength (the degree of association between words in a combination) of well-formed bigrams (two-word combinations) and trigrams (three-word combinations). The second analysis presents a qualitative investigation of uses of IDK in dyadic exchanges. //
Outcomes & Results: Analysis 1 revealed that residual trigrams in Broca’s aphasia were more strongly collocated in comparison to language produced by CPs. There was no difference in frequency-based profiles between dyadic and non-dyadic aphasic speech. Analysis 2 indicated that speakers with Broca’s aphasia and CPs used IDK to achieve a variety of communicative functions. However, patterns specific to each participant group were found. //
Conclusions: These findings highlight that frequency-based analysis is useful in explaining residual, grammatically well-formed word combinations in Broca’s aphasia. This study provides evidence that IDK can aid turn construction in aphasia
EChOSim: The Exoplanet Characterisation Observatory software simulator
EChOSim is the end-to-end time-domain simulator of the Exoplanet
Characterisation Observatory (EChO) space mission. EChOSim has been developed
to assess the capability EChO has to detect and characterize the atmospheres of
transiting exoplanets, and through this revolutionize the knowledge we have of
the Milky Way and of our place in the Galaxy. Here we discuss the details of
the EChOSim implementation and describe the models used to represent the
instrument and to simulate the detection. Software simulators have assumed a
central role in the design of new instrumentation and in assessing the level of
systematics affecting the measurements of existing experiments. Thanks to its
high modularity, EChOSim can simulate basic aspects of several existing and
proposed spectrometers for exoplanet transits, including instruments on the
Hubble Space Telescope and Spitzer, or ground-based and balloon borne
experiments. A discussion of different uses of EChOSim is given, including
examples of simulations performed to assess the EChO mission
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A systematic review investigating the effectiveness of exercise training in glycogen storage diseases
Introduction: Glycogen storage diseases (GSDs) are rare inborn errors of carbohydrate metabolism typically with skeletal muscle and liver involvement. In those with skeletal muscle involvement, the majority display symptoms of exercise intolerance which can cause profound exercise limitation and impair everyday living and quality of life (QoL). There are no curative treatments for GSDs, thus therapeutic options, such as exercise training, are aimed at improving QoL by alleviating signs and symptoms. In order to investigate the effectiveness of exercise training in adults with GSDs, we systematically reviewed the literature.
Methods: In this review we conducted searches within SCOPUS and MEDLINE to identify potential papers for inclusion. These papers were independently assessed for inclusion and quality by two authors. We identified 23 studies which included aerobic training, strength training or respiratory muscle training in patients with McArdles (n = 41) and Pompe disease (n = 139).
Results: In McArdle disease, aerobic exercise training improved aerobic capacity (VO2 peak) by 14–111% with further benefits to functional capacity and well-being. Meanwhile, strength training increased muscle peak power by 100–151% and reduced disease severity. In Pompe disease, a combination of aerobic and strength training improved VO2 peak by 9–10%, muscle peak power by 64%, functional capacity and well-being. Furthermore, respiratory muscle training (RMT) improved respiratory muscular strength [maximum inspiratory pressure (MIP) increased by up to 65% and maximum expiratory pressure (MEP) by up to 70%], with additional benefits shown in aerobic capacity, functional capacity and well-being.
Conclusion: This adds to the growing body of evidence which suggests that supervised exercise training is safe and effective in improving aerobic capacity and muscle function in adults with McArdle or Pompe disease. However, the literature base is limited in quality and quantity with a dearth of literature regarding exercise training in other GSD subtypes
Changing women's roles, changing environmental knowledges: evidence from Upper Egypt
The aim of this paper is to investigate the ways in which changing gender roles in a Bedouin community in Upper Egypt, brought about by settlement over the last 20 years on the shores of Lake Nasser, have impacted on the accumulation and development of indigenous environmental knowledges by Bedouin women. The research was carried out among four groups of Ababda Bedouin in the Eastern Desert of Egypt and involved in-depth monthly conversations carried out over a period of 12 months. The main conclusions of the study are that the women of the study area have had to develop new knowledges which, in some cases, are now different from those held by men because of the different economic circumstances in which many find themselves; that these knowledges are fluid, dynamic and ever-changing with their own internal dynamism; and that socially constructed notions of gender are vital in the development process, notions that are sensitive to both men's and women's interests and their interrelationships
The signature of competition in ecomorphological traits across the avian radiation
Competition for shared resources represents a fundamental driver of biological diversity. However, the tempo and mode of phenotypic evolution in deep-time has been predominantly investigated using trait evolutionary models which assume that lineages evolve independently from each other. Consequently, the role of species interactions in driving macroevolutionary dynamics remains poorly understood. Here, we quantify the prevalence for signatures of competition between related species in the evolution of ecomorphological traits across the bird radiation. We find that mechanistic trait models accounting for the effect of species interactions on phenotypic divergence provide the best fit for the data on at least one trait axis in 27 out of 59 clades ranging between 21 and 195 species. Where it occurs, the signature of competition generally coincides with positive species diversity-dependence, driven by the accumulation of lineages with similar ecologies, and we find scarce evidence for trait-dependent or negative diversity-dependent phenotypic evolution. Overall, our results suggest that the footprint of interspecific competition is often eroded in long-term patterns of phenotypic diversification, and that other selection pressures may predominantly shape ecomorphological diversity among extant species at macroevolutionary scales
Interpreting physical performance in professional soccer match-play: Should we be more pragmatic in our approach?
Academic and practitioner interest in the physical performance of male professional soccer players in the competition setting determined via time-motion analyses has grown substantially over the last four decades leading to a substantial body of published research and aiding development of a more systematic evidence-based framework for physical conditioning. Findings have forcibly shaped contemporary opinions in the sport with researchers and practitioners frequently emphasising the important role that physical performance plays in match outcomes. Time-motion analyses have also influenced practice as player conditioning programmes can be tailored according to the different physical demands identified across individual playing positions. Yet despite a more systematic approach to physical conditioning, data indicate that even at the very highest standards of competition, the contemporary player is still susceptible to transient and end-game fatigue. Over the course of this article, the author suggests that a more pragmatic approach to interpreting the current body of time-motion analysis data and its application in the practical setting is nevertheless required. Examples of this are addressed using findings in the literature to examine: a) the association between competitive physical performance and ‘success’ in professional soccer, b) current approaches to interpreting differences in time-motion analysis data across playing positions and, c) whether data can realistically be used to demonstrate the occurrence of fatigue in match-play. Gaps in the current literature and directions for future research are also identified
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