722 research outputs found

    Evolution of the Fucaceae (Phaeophyceae) inferred from nrDNA-ITS

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    Sequences of the internal transcribed spacer region (ITS-1, 5.8S, and ITS-2) of nuclear ribosomal DNA were obtained from 16 species representing all six genera of Fucaceae (Ascophyllum, Fucus, Hesperophycus, Pelvetia, Pelvetiopsis, and Xiphophora) plus one outgroup (Hormosira). Parsimony analysis indicated that the family Fucaceae is monophyletic and that the northern hemisphere taxa are highly divergent from the only southern hemisphere genus, Xiphophora. The genus Pelvetia is not monophyletic because the European P. canaliculata is more closely related to Fucus, Hesperophycus, and Pelvetiopsis than to other Pelvetia species. We establish Silvetia, gen. nov. and transfer the 3 Pacific species of Pelvetia to the new genus. Fucus is monophyletic and not ancestral in the Fucaceae. The ITS sequences identified two strongly supported lineages within Fucus, one with F. serratus sister to the clade containing F. gardneri, F. distichus, and F. evanescens and a second including F. vesiculosus, F. spiralis, F. ceranoides, and F. virsoides. The ITS was not useful for resolving relationships within each of these clusters and between populations of F. vesiculosus. Within-individual variation in ITS sequences is high in Fucus, a derived genus, compared to Ascophyllum, a more ancestral genus. Mapping of the two characters that form the basis of Powell’s model for speciation in the Fucaceae showed that 1) number of eggs per oogonium has not followed a gradual reduction and that 2) monoecy/dioecy has changed several times during evolution of this family

    A systematic review of three approaches for constructing physical activity messages: What messages work and what improvements are needed?

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    <p>Abstract</p> <p>Background</p> <p>To motivate individuals to adhere to a regular physical activity regime, guidelines must be supplemented with persuasive messages that are disseminated widely. While substantial research has examined effective strategies for disseminating physical activity messages, there has been no systematic effort to examine optimal message content. This paper reviews studies that evaluate the effectiveness of three approaches for constructing physical activity messages including tailoring messages to suit individual characteristics of message recipients (message tailoring), framing messages in terms of gains versus losses (message framing), and targeting messages to affect change in self-efficacy (i.e., a theoretical determinant of behavior change).</p> <p>Methods</p> <p>We searched the MEDLINE, PsycINFO, EMBASE and CINAHL databases up to July 2008. Relevant reference lists also were searched. We included intervention trials, field experiments, and laboratory-based studies that aimed to test the efficacy or effectiveness of tailored messages, framed messages and self-efficacy change messages among healthy adults. We used a descriptive approach to analyze emerging patterns in research findings. Based on this evidence we made recommendations for practice and future research.</p> <p>Results</p> <p>Twenty-two studies were identified. Twelve studies evaluated message tailoring. In 10 of these studies, tailored messages resulted in greater physical activity than a control message. Six studies evaluated framed messages. Five of these studies demonstrated that gain-framed messages lead to stronger intentions to be active compared to a control message. Moreover, a gain-frame advantage was evident in three of the four studies that assessed physical activity. Four studies evaluated self-efficacy change messages. The two studies that used an experimental design provide a clear indication that individuals' beliefs can be affected by messages that incorporate types of information known to be determinants of self-efficacy. Overall, strong evidence to support definitive recommendations for optimal message content and structure was lacking.</p> <p>Conclusions</p> <p>Additional research testing the optimal content of messages used to supplement physical activity guidelines is needed. Tailored messages, gain-framed messages, and self-efficacy change messages hold promise as strategies for constructing physical activity messages and should be a focus of future research.</p

    Homeless in Galilee

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    This article has located Jesus’ saying about homelessness in the context of the Roman Empire as it was experienced in Galilee. Homelessness is part of a broader picture that translates into loss of access to the resources of the land. The thesis is that in light of a theology of land resulting from the development of Abrahamic covenant traditions and the prophetic hope expressed especially in Isaiah, Ezekiel and Psalm 37, Jesus proclaimed God’s kingdom as God’s rule over heaven and earth, which implicates restoration of equitable access to the resources of the earth. The Lord’s Prayer, presumptions about the water of Jacob’s well in John 4 and the parable of the unjust steward in Luke 16 are used to demonstrate understandings of violations of equitable access according to Abrahamic covenant traditions and the hope for the restoration thereof

    History on trial: evaluating learning outcomes through audit and accreditation in a national standards environment

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    This paper uses a trial audit of history programs undertaken in 2011-2012 to explore issues surrounding the attainment of Threshold Learning Outcomes (TLOs) in an emerging Australian national standards environment for the discipline of history. The audit sought to ascertain whether an accreditation process managed by the discipline under the auspices of the Australian Historical Association (AHA) could be based on a limited-intervention, “light-touch” approach to assessing attainment of the TLOs. The results of the audit show that successful proof of TLO attainment would only be possible with more active intervention into existing history majors and courses. Assessments across all levels of history teaching would have to be designed, undertaken, and marked using a rubric matched to the TLOs. It proved unrealistic to expect students to demonstrate acquisition of the TLOs from existing teaching and assessment practices. The failure of the “light-touch” audit process indicates that demonstrating student attainment under a national standards regime would require fundamental redevelopment of the curriculum. With standards-based approaches to teaching and learning emerging as international phenomena, this case study resonates beyond Australia and the discipline under investigation.Sean Brawley, Jennifer Clark, Chris Dixon, Lisa Ford, Erik Nielsen, Shawn Ross, Stuart Upto

    Resonant scattering of positronium as a quasifree electron

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    In order to clarify the physics underlying the observations of the electronlike behavior of positronium (Ps) and its resonant scattering from CO2, we have measured the Ps+N2 total cross section and found it also to exhibit significant structure. Analysis of the resonances reveals that Ps is distorted in the collisions and classical trajectory Monte Carlo calculations indicate that the electron is on average closer to the target than the positron, which may in turn bind resonantly to the ensuing temporary negative ion. This description of the nature of Ps resonances agrees with long-standing theoretical predictions

    Cohesion, team mental models, and collective efficacy: Towards an integrated framework of team dynamics in sport

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    A nomological network on team dynamics in sports consisting of a multi-framework perspective is introduced and tested. The aim was to explore the interrelationship among cohesion, team mental models (TMM), collective-efficacy (CE), and perceived performance potential (PPP). Three hundred and forty college-aged soccer players representing 17 different teams (8 female and 9 male) participated in the study. They responded to surveys on team cohesion, TMM, CE and PPP. Results are congruent with the theoretical conceptualization of a parsimonious view of team dynamics in sports. Specifically, cohesion was found to be an exogenous variable predicting both TMM and CE beliefs. TMM and CE were correlated and predicted PPP, which in turn accounted for 59% of the variance of objective performance scores as measured by teams’ season record. From a theoretical standpoint, findings resulted in a parsimonious view of team dynamics, which may represent an initial step towards clarifying the epistemological roots and nomological network of various team-level properties. From an applied standpoint, results suggest that team expertise starts with the establishment of team cohesion. Following the establishment of cohesiveness, teammates are able to advance team-related schemas and a collective sense of confidence. Limitations and key directions for future research are outlined

    The Effects of Ketone Supplementation on Recovery in Collegiate Male Soccer Players: Pilot Trial

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    Complete Break Up of Ortho Positronium (Ps)- Hydrogenic ion System

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    The dynamics of the complete breakup process in an Ortho Ps - He+ system including electron loss to the continuum (ELC) is studied where both the projectile and the target get ionized. The process is essentially a four body problem and the present model takes account of the two centre effect on the electron ejected from the Ps atom which is crucial for a proper description of the ELC phenomena. The calculations are performed in the framework of Coulomb Distorted Eikonal Approximation. The exchange effect between the target and the projectile electron is taken into account in a consistent manner. The proper asymptotic 3-body boundary condition for this ionization process is also satisfied in the present model. A distinct broad ELC peak is noted in the fully differential cross sections (5DCS) for the Ps electron corroborating qualitatively the experiment for the Ps - He system. Both the dynamics of the ELC from the Ps and the ejected electron from the target He+ in the FDCS are studied using coplanar geometry. Interesting features are noted in the FDCS for both the electrons belonging to the target and the projectile.Comment: 14 pages,7 figure

    Efficacy of Online Training for Improving Camp Staff Competency

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    Preparing competent staff is a critical issue within the camp community. This quasi-experimental study examined the effectiveness of an online course for improving staff competency in camp healthcare practices among college-aged camp staff and a comparison group (N = 55). We hypothesized that working in camp would increase competency test scores due to opportunities for staff to experientially apply knowledge learned online. Hierarchical linear modeling was used to analyse the cross-level effects of a between-individuals factor (assignment to experimental or comparison group) and within-individual effects of time (pre-test, post-test #1, and post-test #2) on online course test scores. At post-test #2, the difference in average test scores between groups was ~30 points, with the treatment group scoring lower on average than the comparison group. Factors that may have influenced these findings are explored, including fatigue and the limited durability of online learning. Recommendations for research and practice are discussed
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