11,306 research outputs found
Is a community still a community? Reviewing definitions of key terms in community ecology
Community ecology is an inherently complicated field, confounded by the conflicting use of fundamental terms. Nearly two decades ago, Fauth etal. (1996) demonstrated that imprecise language led to the virtual synonymy of important terms and so attempted to clearly define four keywords in community ecology; community, assemblage, guild, and ensemble. We revisit Fauth etal.\u27s conclusion and discuss how the use of these terms has changed over time since their review. An updated analysis of term definition from a selection of popular ecological textbooks suggests that definitions have drifted away from those encountered pre-1996, and slightly disagreed with results from a survey of 100 ecology professionals (comprising of academic professors, nonacademic PhDs, graduate and undergraduate biology students). Results suggest that confusion about these terms is still widespread in ecology. We conclude with clear suggestions for definitions of each term to be adopted hereafter to provide greater cohesion among research groups
Zur Bedeutung von Unterrichtsqualität für die naturwissenschaftliche Kompetenz von Grundschulkindern. Ein Fokus auf Kinder mit ungünstigen Lernvoraussetzungen
Research on classroom instruction has consistently identified characteristics that contribute to student learning. For instance, these include structural-organizational aspects (e.g., classroom management) and affective aspects (e.g., classroom social climate). The idea that the effects of instruction may differentially depend on students’ characteristics has been investigated within the scope of aptitude-treatment-interactions (ATI) research. This study of elementary school (1,041 students, 54 classes) builds on ATI and examines main effects and interaction effects of instructional quality (i.e., classroom management and classroom social climate) and individual risks of school failure (i.e., demographic risk: immigration background or functional risk: low cognitive ability scores) on students’ science competence. Based on hierarchical linear modeling and class-level aggregated student ratings of instructional quality, results show a positive link between classroom social climate and science competence but not for classroom management and science competence. As its most important finding, our study demonstrates the compensatory capacity of instructional quality to narrow the achievement gap between students at risk and their peers. Furthermore, classroom management also counteracted risk of school failure when controlling for students’ language proficiency. (DIPF/Orig.)Im Rahmen von Forschung zu gutem Unterricht wurden Unterrichtsqualitätsmerkmale identifiziert, die mit dem Lernerfolg von Schülerinnen und Schülern verbunden sind. Diese beinhalten bspw. strukturell-organisatorische Aspekte, wie Classroom Management, oder affektive Aspekte, wie das Klassenklima. Dass der Lernerfolg nicht nur von Unterrichtsmerkmalen, sondern auch von deren Wechselspiel mit den individuellen Lernervoraussetzungen abhängt, ist Thema der Forschung zu Aptitude-Treatment-Interactions (ATI). Gegenwärtig erfährt diese Forschung erneute Aufmerksamkeit und bestätigende empirische Befunde. Diese Studie an deutschen Grundschulen (1041 Kinder aus 54 Klassen) knüpft daran an und prüft Haupt- und Interaktionseffekte von Unterrichtsqualitätsmerkmalen (Classroom Management und Klassenklima) sowie individuellen Lernvoraussetzungen (Migrationshintergrund oder geringe kognitive Grundfähigkeiten) für die naturwissenschaftliche Kompetenz von Grundschulkindern. Ergebnisse aus Mehrebenenanalysen zeigen einen positiven Zusammenhang zwischen Klassenklima und naturwissenschaftlicher Kompetenz, nicht aber zwischen Classroom Management und naturwissenschaftlicher Kompetenz. Darüber hinaus zeigten sich Interaktionseffekte zwischen Unterrichtsqualitäts- und Schülermerkmalen dahingehend, dass Unterrichtsqualität einen ausgleichenden Effekt auf die Leistungen von Kindern mit ungünstigen Lernvoraussetzungen und diejenigen ihrer Mitschülerinnen und Mitschüler ausübte. Dieser kompensatorische Effekt zeigte sich für Classroom Management auch nach Kontrolle sprachlicher Kompetenzen. (DIPF/Orig.
A systematic review of the relationship between behavioral and psychological symptoms (BPSD) and caregiver well-being
Background: Behavioural and psychological symptoms in dementia (BPSD) are important predictors of institutionalisation as well as caregiver burden and depression. Previous reviews have tended to group BPSD as one category with little focus on the role of the individual symptoms. This review investigates the role of the individual symptoms of BPSD in relation to the impact on different measures of family caregiver wellbeing. Methods: Systematic review and meta-analysis of articles published in English between 1980 and December 2015 reporting which BPSD affect caregiver wellbeing. Article quality was appraised using the Downs and Black Checklist (1998). Results: 40 medium and high quality quantitative articles met the inclusion criteria, 16 were suitable to be included in a meta-analysis of mean distress scores. Depressive behaviours were the most distressing for caregivers followed by agitation/aggression and apathy. Euphoria was the least distressing. Correlation coefficients between mean total behaviour scores and mean distress scores were pooled for 4 studies. Irritability, aberrant motor behaviour and delusions were the most strongly correlated to distress, disinhibition was the least correlated. Conclusion: The evidence is not conclusive as to whether some BPSD impact caregiver wellbeing more than others. Studies which validly examined BPSD individually were limited, and the included studies used numerous measures of BPSD and numerous measures of caregiver wellbeing. Future research may benefit from a consistent measure of BPSD, examining BPSD individually, and by examining the causal mechanisms by which BPSD impact wellbeing by including caregiver variables so that interventions can be designed to target BPSD more effectively
Lichens in the nests of European starling Sturnus vulgaris serve a mate attraction rather than insecticidal function
The European starling Sturnus vulgaris is a hole-nesting bird in which the male builds a voluminous nest using a wide variety of materials such as twigs, grass, leaves, feathers, and lichens. The function of lichens in starling nests has not been assessed until now and we hypothesize that this material is related to a mate attraction function or is used to protect nestlings from parasites due to the presence of secondary compounds with insecticidal effects with the lichens. We aimed to identify the lichen species and frequency of lichen use in European starling nests, and to determine if the presence of this material is correlated with mate attraction or with an insecticidal function. We found lichens in 45% of nests, mainly represented by Ramalina celastri. The lichens were added to the nests mainly before the beginning and at the end of nest building and egg-laying started earlier in nests with lichens than those without lichens. No association was found between the presence of lichen and the intensity of Philornis larvae (Diptera), a parasite that infests starling nestlings. Our results suggest that the addition of lichens could be related to mate attraction and a stimulus for the beginning of egg-laying but did not have an antiparasitic function in European starling nests.Fil: Ibañez, Lucía Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Departamento Científico Zoología Vertebrados; ArgentinaFil: García, Renato Andrés. Laboratorio de Entrenamiento Multidisciplinario para la Investigación Tecnológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fiorini, Vanina Dafne. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Montalti, Diego. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Departamento Científico Zoología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Hatching asynchrony, survival, and the fitness of alternative adult morphs in \u3ci\u3eAmbystoma talpoideum\u3c/i\u3e
The mole salamander, Ambystoma talpoideum, exhibits both aquatic (gilled) and terrestrial (metamorphosed) adult morphologies. Previous studies have shown the existence of body-size advantages associated with the terrestrial morph in A. talpoideum and other polymorphic salamanders (e.g., A. tigrinum). However, aquatic adult A. talpoideum mature at a younger age and often breed earlier than terrestrial adults. We tested the hypothesis that early maturation and reproduction in aquatic adults increase fitness (irrespective of body size). We reared larval A. talpoideum in mesocosms and varied the timing of hatching, with early-hatching larvae representing the offspring from early-breeding aquatic adults, and late-hatching larvae representing the offspring of later-breeding terrestrial adults. Our results demonstrate significantly higher survival rates among early-hatchlings relative to late-hatching conspecifics, supporting the hypothesis that early reproduction may be an important mechanism mediating the polymorphism in A. talpoideum. We discuss our results within the context of size-based models of the fitness of alternative life-cycles
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Pseudacris ornata
Number of Pages: 8Integrative BiologyGeological Science
Kinetic Analysis of Lower Body Resistance Training Exercises
This study evaluated and compared the peak vertical ground reaction force (GRF) and rate of force development (RFD) for the eccentric and concentric phases of 4 lower body resistance training exercises, including the back squat, deadlift, step-up, and forward lunge. Sixteen women performed 2 repetitions of each of the 4 exercises at a 6 repetition maximum load. Kinetic data were acquired using a force platform. A repeated measures ANOVA was used to evaluate the differences in GRF between the exercises. Results revealed significant main effects for GRF both the eccentric (p ≤ 0.001) and concentric (p ≤ 0.001) phases. Significant main effects were also found for RFD for the eccentric (p ≤ 0.001) and concentric phases (p ≤ 0.001). Force and power requirements and osteogenic potential differ between these resistance training exercises
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A novel approach to the design of DSP systems using minimum complexity Finite State Machines
The paper presents a new and different approach to the design and realisation of Digital Signal Processing (DSP)systems by utilising Finite State Machines (FSM). The DSP system is modelled by mapping all its potential states into an FSM, whose complexity is usually very high. The FSM mirrors the complete functionality of the system and thus describes its behaviour in full detail. Examples for FSMs of first and second order digital recursive filters are provided and the current version of the software simulating the FSM corresponding to any linear time-invariant DSP system is described. The potential of this approach including state reduction techniques as well as the inclusion of non-linear DSP systems is also outlined, and further future research intentions are briefly explored
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