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  • 1
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    Phytolith evidence for the extent and nature of prehistoric Californian grasslands (2013)
    Sage
    In: Holocene
    Details
    Publication Date: 2013-10-15
    Description: Californian grasslands have been radically transformed by cultivation and exotic species invasions that began with European settlement in 1769. Because native species contribute only a small percentage of total vegetation cover at most grassland sites in California today, there has been a long-standing controversy regarding the extent and composition of prehistoric grasslands. We used phytolith analysis of soil samples from 153 spatially diverse grassland sites currently cultivated or dominated by exotic annual grasses to provide the first direct evidence that, except for areas near the coast, grass was generally a minor component of the vegetation. Most of the arid, non-wetland Central Valley and surrounding foothills probably had very low grass cover. Combining our data with historical accounts of vegetation encountered by early explorers in California and relict analysis of native species in existing grassland patches, it appears that while the extent of prehistoric grassland was probably similar to the current extent of exotic annual grassland, most areas were likely dominated by a highly diverse assemblage of herbaceous species, composed largely of annual forbs adapted to exploit local environmental heterogeneity. Phytolith analysis should be routinely performed in California to guide grassland restoration efforts. The technique can also be used to reconstruct prehistoric vegetation of highly altered grassland ecosystems worldwide.
    Print ISSN: 0959-6836
    Electronic ISSN: 1477-0911
    Topics: Geography , Geosciences
    Published by Sage
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  • 2
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    Stomatal density and stomatal index of fossil Buxus from coprolites of extinct Myotragus balearicus Bate (Artiodactyla, Caprinae) as evidence of increased CO2 concentration during the late Holocene (2014)
    Sage
    In: Holocene
    Details
    Publication Date: 2014-06-10
    Description: Stomatal density of plants may vary depending on environmental factors, such as CO 2 concentration. Under the current atmospheric conditions, it is expected that leaves have different stomatal density than they had hundreds or thousands of years ago, due to the rise in CO 2 in the atmosphere. Coprolites of the extinct Myotragus balearicus from Cova Estreta (Pollença, Mallorca), with a radiocarbon age of 3775–3640 cal. bc , have been used to study the diet of this bovid. A significant amount of epidermal fragments of Buxus was found in the faecal material. Three coprolites were used to estimate the stomatal density and stomatal index of Buxus epidermal fragments from this period. Samples of the endangered Buxus balearica , the sole species of Buxus currently present on Mallorca, and samples of the Buxus sempervirens , present in the nearest mainland, were also collected in different locations. Leaves were examined using microscopy to determine and compare the stomatal density and stomatal index between current plant material and coprolite material. The results indicated a higher value for stomatal index (12.71) and stomatal density (297.61 stomata/mm 2 ) in leaves from the coprolites versus leaves of the living B. balearica and B. sempervirens species (7.99 and 227.77 stomata/mm 2 respectively). These results could provide a palaeobotanic evidence of a change in atmospheric CO 2 concentration since mid-Holocene in the Mediterranean basin.
    Print ISSN: 0959-6836
    Electronic ISSN: 1477-0911
    Topics: Geography , Geosciences
    Published by Sage
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  • 3
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    Perceived Novelty Support and Psychological Needs Satisfaction in Physical Education (2020)
    Molecular Diversity Preservation International
    Details
    Publication Date: 2020-06-11
    Description: In recent years, novelty has been proposed as a potential fourth basic psychological need. In the present study, the behavior of novelty resulting from support from the Physical Education teacher was evaluated in 723 students with an average age of 13.30 years old. The first objective was to validate the Support for Basic Psychological Needs-4 (SBPN-4) in Physical Education questionnaire, which included support for the novelty factor. The second objective was to test the mediation model in order to confirm the effect of support for novelty in relation to basic psychological needs and intrinsic motivation. The results obtained show that the Support for Basic Psychological Needs-4 (SBPN-4) questionnaire is a valid and reliable tool. On the other hand, support for novelty predicts satisfaction of basic psychological needs, particularly novelty satisfaction, which in turn predicts intrinsic motivation. These results show how the students are capable of perceiving the teacher’s support for novelty and how this positively influences their intrinsic motivation. Further investigations are required to continue developing our knowledge of the role of novelty as a basic psychological need.
    Print ISSN: 1661-7827
    Electronic ISSN: 1660-4601
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Published by Molecular Diversity Preservation International
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  • 4
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    Validation of the Achievement Emotions Questionnaire for Physical Education (AEQ-PE) (2020)
    Molecular Diversity Preservation International
    Details
    Publication Date: 2020-06-24
    Description: The fundamental role of emotions in education has been revealed in recent years. The control-value theory of achievement emotions has been postulated as one of the most used theories in this field. Thanks to the Achievement Emotions Questionnaire (AEQ), achievement emotions have been measured in different subjects and countries. The purpose of this research was to adapt and validate this questionnaire to assess achievement emotions in physical education. The sample of participants consisted of 902 (Mage = 13.15, SD = 1.17) secondary education students from various secondary schools in Spain. The psychometric properties of the Achievement Emotions Questionnaire for Physical Education (AEQ-PE) indicate that the scales are reliable and valid, as demonstrated by exploratory and confirmatory factor analysis, temporal stability, internal consistency and regression analysis. Considering the results achieved in the present study, the AEQ-PE opens a range of possibilities for both teachers and researchers. This instrument will help to understand the role of emotions in student learning and their motivation towards physical education.
    Print ISSN: 1661-7827
    Electronic ISSN: 1660-4601
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Published by Molecular Diversity Preservation International
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  • 5
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    Effects of Cooperative-Learning Interventions on Physical Education Students’ Intrinsic Motivation: A Systematic Review and Meta-Analysis (2020)
    Molecular Diversity Preservation International
    Details
    Publication Date: 2020-06-21
    Description: The aim was to review the effects of cooperative learning interventions on intrinsic motivation in physical education students, as well as to conduct a meta-analysis to determinate the overall effect size of these interventions. The PRISMA guidelines were followed to conduct this systematic review and meta-analysis. The PEDro Scale was used to assess the risk of bias and the GRADE approach was used to evaluate the quality of the evidence. A total of five studies fulfilled the inclusion criteria and they were included in the meta-analysis. Effect size for intrinsic motivation of each study was calculated using the means and standard deviations of the Perceived Locus of Causality Scale (PLOC) before and after the intervention. The overall effect size for intrinsic motivation was 0.38 (95% CI from 0.17 to 0.60) while the heterogeneity was large. Although four of the five studies reported significant within-group improvements in intrinsic motivation, only three studies showed significant between-group differences in favor of the experimental group. The findings showed that program duration and participant age may be relevant factors that must be considered by educators and researchers to conduct future effective interventions. Cooperative learning interventions could be a useful teaching strategy to improve physical education students’ intrinsic motivation. However, given the large heterogeneity and the low quality of the evidence, these findings must be taken with caution.
    Print ISSN: 1661-7827
    Electronic ISSN: 1660-4601
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Published by Molecular Diversity Preservation International
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  • 6
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    Decisive Factors for a Greater Performance in the Change of Direction and Its Angulation in Male Basketball Players (2020)
    Molecular Diversity Preservation International
    Details
    Publication Date: 2020-09-10
    Description: A study was made to initially evaluate whether the age category directly could influence anthropometric measurements, functional movement tests, linear sprint (30 m) and strength. Moreover, and as the main purpose, this study aimed to examine the relationship between the time execution and angles in different changes of direction (COD) test with the analyzed sport performance variables. A total sample of 23 basketball players (age: 17.5 ± 2.42 years; height: 184.6 ± 6.68 cm; body weight: 78.09 ± 11.9 kg). Between-groups’ comparison explored the differences between basketball categories (Junior, n = 12; Senior, n = 11). The COD variables were divided by the time execution into low responders (LR) and high responders (HR) to establish comparisons between groups related to COD time execution. Pearson’s correlation coefficient was used to establish correlations between different CODs and sport performance variables. The results showed a greater influence of age category upon COD performance, especially when the cutting angle was sharper (7.05% [Confidence limits (CL) 90%: 2.33; 11.99]; Quantitative chances (QC) 0/2/98), in which athletes need greater application of strength. Moreover, the sharper the angle or the larger the number of cuts made, the greater the relationship with the vertical force–velocity profile (−42.39 [CL 90%: −57.37; −22.16]; QC 100/0/0%). Thus, the usefulness of the f–v profile to implement training programs that optimize the f–v imbalance and the improvement of the COD performance in basketball players is suggested.
    Print ISSN: 1661-7827
    Electronic ISSN: 1660-4601
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Published by Molecular Diversity Preservation International
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  • 7
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    Perceived Performance, Intrinsic Motivation and Adherence in Athletes (2020)
    Molecular Diversity Preservation International
    Details
    Publication Date: 2020-12-16
    Description: Sports performance depends on a complex interaction of variables, such as psychological, physical, technical and tactical abilities. The purpose of the three studies described in this article was to validate an instrument to measure perceived performance in athletes (studies 1 and 2), and to analyze the predictive power of perceived performance, basic psychological needs and intrinsic motivation on the intention to be physically active (which was used as a predictor of adherence to sport) (study 3). In study 1, the Perceived Performance in Sports Questionnaire was validated in the Spanish sports context, analyzing its factorial structure, reliability, and temporal stability with 146 soccer players. The objective of study 2 was to check the factorial structure of the questionnaire with an objective performance measure (points scored and time played). The sample was 180 young basketball players. The objective of study 3 was to analyze the predictive power of basic psychological needs in exercise, intrinsic motivation, and perceived performance on the intention to be physically active in 339 athletes of fifteen different sports. The results show the reliability and validity of the questionnaire, and positive correlations with the points scored. Finally, the analysis of the structural equation model showed that the satisfaction of the need for competence predicted perceived performance and intrinsic motivation predicted perceived performance and intention to remain physically active.
    Print ISSN: 1661-7827
    Electronic ISSN: 1660-4601
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Published by Molecular Diversity Preservation International
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