Cannibalism as a life boat mechanism

Under certain conditions a cannibalistic population can survive when food for the adults is too scarce to support a non-cannibalistic population. Cannibalism can have this lifeboat effect if (i) the juveniles feed on a resource inaccessible to the adults; and (ii) the adults are cannibalistic and thus incorporate indirectly the inaccessible resource. Using a simple model we conclude that the mechanism works when, at low population densities, the average yield, in terms of new offspring, due to the energy provided by one cannibalized juvenile is larger than one

The shape of ecological networks

We study the statistics of ecosystems with a variable number of co-evolving species. The species interact in two ways: by prey-predator relationships and by direct competition with similar kinds. The interaction coefficients change slowly through successful adaptations and speciations. We treat them as quenched random variables. These interactions determine long-term topological features of the species network, which are found to agree with those of biological systems.Comment: 4 pages, 2 figure

Classification of coastal-marine habitats in Gwatr Bay using ecological standard classification (CMECS)

This research was conducted during 2007-2008 with the main aim of classifying marine coastal habitats in Gwatr Bay located in Iran-Pakistan border, south east of Sistan-Blaluchetan Province. We used Coastal-Marine Ecological Standard Classification (CMECS) with three data layers covering water column, benthic cover classifier and geomorphology. Layers and habitats information were analyzed in a GIS environment and the indicator species were determined. WCC classification was done based on temperature, salinity and clarity classifiers for Ichthyoplankton communities. The result showed that two main seasonal habitats including spring habitat (spring, summer and winter) and fall habitat, affected by the monsoon season is present in the area. Also we considered particle size and total organic matter in sediment as classifiers for benthic habitats which indicated two different habitats based on distances from shore. Habitats were divided into unmixed macro-benthos community (polychaete) and mixed macro-benthos community including: Polychaete, Amphipoda and Gastropoda. The habitats were shown on digital GIS maps with their specific codes

The Influence of Chronotype and Grit on Lifestyle and Physical Activity

Background:  The chronotype of a person refers to an individual's natural sleep-wake cycle and whether that individual prefers morning or evening activities, and grit is an individual's perseverance and passion for long-term goals.Aim: The purpose of this study was to investigate the relationship between grit, chronotype, physical activity, and leading a healthy lifestyle in college-age students.Methods:  Health and fitness data (i.e., chronotype, grit, lifestyle assessment score, and daily steps) from 431 first-semester university students at a private college were collected and analyzed. Results: This study found that grit and chronotype both have significant correlations with living a healthy lifestyle and with physical activity. Grit more accurately predicts a person's lifestyle (β = -13.712, r = 0.39, p < 0.0001) while chronotype more accurately predicts the physical activity, or steps, of a person (β = 66.48, r = .19, p = .0001). Chronotype can also accurately predict the grit of a person (r = .25, p < .0001), and it was found that morning people tend to have more grit.Conclusions:  This study concluded that grit, chronotype, steps, and a healthy lifestyle are all significantly correlated with each other. Knowing the relationship between endogenous chronotype, grit, and living a physically active and healthy lifestyle can help inform policy decisions related to the goal of strengthening an institution's inclusive and healthy academic community

'Support our networking and help us belong!': listening to beginning secondary school science teachers

This study, drawing on the voice of beginning teachers, seeks to illuminate their experiences of building professional relationships as they become part of the teaching profession. A networking perspective was taken to expose and explore the use of others during the first three years of a teacher’s workplace experience. Three case studies, set within a wider sample of 11 secondary school science teachers leaving one UK university’s PostGraduate Certificate in Education, were studied. The project set out to determine the nature of the networks used by teachers in terms of both how they were being used for their own professional development and perceptions of how they were being used by others in school. Affordances and barriers to networking were explored using notions of identity formation through social participation. The focus of the paper is on how the teachers used others to help shape their sense of belonging to this, their new workplace. The paper develops ideas from network theories to argue that membership of the communities are a subset of the professional inter‐relationships teachers utilise for their professional development. During their first year of teaching, eight teachers were interviewed, completing 13 semi‐structured interviews. This was supplemented in Year 2 by a questionnaire survey of their experiences. In the third year of the programme, 11 teachers (including the original sample of eight) were surveyed using a network mapping tool in which they represented their communications with people, groups and resources. Finally, three of the teachers (common to both samples) were then interviewed specifically about their networking practices and experiences using the generation of their network map as a stimulated recall focus. The implications of the analysis of these accounts are that these beginning teachers did not perceive of themselves wholly as novices and that their personal aspirations to increase participation in practical science, develop a career or work for pupils holistically did not always sit comfortably with the school communities into which they were being accommodated. While highlighting the importance of trust and respect in establishing relationships, these teachers’ accounts highlight the importance of finding ‘peers’ from whom they can find support and with whom they can reflect and potentially collaborate towards developing practice. They also raise questions about who these ‘peers’ might be and where they might be found

Self-Assemblage and Quorum in the Earthworm Eisenia fetida (Oligochaete, Lumbricidae)

Despite their ubiquity and ecological significance in temperate ecosystems, the behavioural ecology of earthworms is not well described. This study examines the mechanisms that govern aggregation behaviour specially the tendency of individuals to leave or join groups in the compost earthworm Eisenia fetida, a species with considerable economic importance, especially in waste management applications. Through behavioural assays combined with mathematical modelling, we provide the first evidence of self-assembled social structures in earthworms and describe key mechanisms involved in cluster formation. We found that the probability of an individual joining a group increased with group size, while the probability of leaving decreased. Moreover, attraction to groups located at a distance was observed, suggesting a role for volatile cues in cluster formation. The size of earthworm clusters appears to be a key factor determining the stability of the group. These findings enhance our understanding of intra-specific interactions in earthworms and have potential implications for extraction and collection of earthworms in vermicomposting processes