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Designing manipulative ecological experiments is a complex and time-consuming process that is problematic to teach in traditional undergraduate classes. This study investigates the effectiveness of using a computer simulation--the Virtual Rocky Shore (VRS)--to facilitate rapid, student-centred learning of experimental design. We gave a series of tests to biology undergraduates to determine how well experimental design and data analysis was understood: 1) before any teaching sessions on this topic; 2) after theory sessions on experimental design; and 3) after an additional practical session using the VRS. Due to poor weather, sample sizes were small with a total of 12 students participating in all three sessions. Nevertheless, marks increased significantly between the initial and final tests (1 and 3). The variability of marks during test 2 was also significantly higher than for the other two tests. Thus some students learned experimental design effectively from the theory sessions alone, while others only understood the process after the experiential learning component of the VRS. Feedback from students on the process was mainly positive, although some students found the VRS too abstract, indicating that the use of digital learning resources may need to be supported by real experience in the field or laboratory. (Contains 1 table and 1 figure.)

Artificial reefs are now commonly used as a tool to restore degraded coral reefs and have a proven potential to enhance biodiversity. Despite this, there is currently a limited understanding of ecosystem functioning on artificial reefs, and how this compares to natural reefs. We used water sampling (bottom water sampling and pore water sampling), as well as surface sediment sampling and sediment traps, to examine the storage of total organic matter (as a measure of total organic carbon) and dynamics of dissolved inorganic nitrate, nitrite, phosphate and ammonium. These biogeochemical parameters were used as measures of ecosystem functioning, which were compared between an artificial reef and natural coral reef, as well as a degraded sand flat (as a control habitat), in Bali, Indonesia. We also linked the differences in these parameters to observable changes in the community structure of mobile, cryptobenthic and benthic organisms between habitat types. Our key findings showed: (1) there were no significant differences in inorganic nutrients between habitat types for bottom water samples, (2) pore water phosphate concentrations were significantly higher on the artificial reef than on both other habitats, (3) total organic matter content in sediments was significantly higher on the coral reef than both other habitat types, and (4) total organic matter in sediment traps in sampling periods May and September were higher on coral reefs than other habitats, but no differences were found in November. Overall, in terms of ecosystem functioning (specifically nutrient storage and dynamics), the artificial reef showed differences from the nearby degraded sand flat, and appeared to have some similarities with the coral reef. However, it was shown to not yet be fully functioning as the coral reef, which we hypothesise is due its relatively less complex benthic community and different fish community. We highlight the need for longer term studies on artificial reef functioning, to assess if these habitats can replace the ecological function of coral reefs at a local level., Author(s): Zach Boakes [sup.1] , I. Gusti Ngurah A. Suryaputra [sup.2] , Alice E. Hall [sup.3] , Daniel J. Franklin [sup.1] , Richard Stafford [sup.1] Author Affiliations: (1) grid.17236.31, 0000 [...]

Coastal habitats are important for commercially exploited and protected species of fish and larger mobile invertebrates. The addition of artificial structures within the marine environment has the potential to alter the connectivity between habitats and to affect metapopulations of a region. Baited remote underwater videos (BRUV) were used to investigate the spatial and seasonal variation in abundance of adult and juvenile mobile species associated with subtidal natural and artificial habitats within Poole Bay on the south coast of England in 2019. Metrics included the relative maximum abundance (MaxN), number of species seen (S), assemblage structure and size range of fish. Higher values of MaxN and S were recorded on artificial structures in the spring and early summer; however, this pattern was reversed by mid-summer and early autumn when more fish were recorded on the natural reefs. Yet overall differences in MaxN and S between habitats were not significant. Differences in assemblage composition between habitats varied monthly, but this was mostly driven by particular sites. Although most fish observed were juveniles, there were some seasonal differences in the size of fish using natural and artificial sites, especially bib (Trisopterus luscus), black bream (Spondyliosoma cantharus), bass (Dicentrarchus labrax) and pollack (Pollachius pollachius). The artificial habitats in this region appeared to be important in certain months, so temporal studies of this type need to be incorporated within surveys, particularly those in proximity to protected areas., Author(s): Alice E. Hall [sup.1] , Roger J. H. Herbert [sup.1] , Richard Stafford [sup.1] Author Affiliations: (1) grid.17236.31, 0000 0001 0728 4630, Department of Life and Environmental Sciences, Faculty [...]

Many ecological communities exist in a stable state where, if undisturbed, no net change will occur in the populations or in the interactions between the component parts of the system. In this paper we present computational methods (evolutionary algorithms and random searches) to parameterize mathematical models that describe communities in stable states. The initial parameterization of the model requires only 'best guess' estimates for parameters and can therefore be used in data-poor situations. The technique locates the stable state that occurs with minimum deviation from these parameters. Alternative stable states in which the community may exist after a disturbance event can also be assessed using this technique, even though the number of alternative states may be large. Using available but incomplete data from an intertidal grazer/biofilm community, we created a prediction of the dynamics of both a pre-and post-disturbance community. Using limited data, we then predicted the most likely post-disturbance community, which proved to be a good match to experimental data, indicating the usefulness of this technique as a predictive tool., Introduction A community is in a stable state when each population in the community shows no net change in size and no changes occur in intra- or inter-specific interactions (Lewontin, [...]

Dietary magnesium (Mg) is essential for the maintenance of glutathione in erythrocytes. Mg deficiency results in the oxidative depletion of glutathione, causing an increase in vasodilating peptides. It is suggested that an increase in these peptides stimulates nitric oxide (NO) production. A study of Mg levels and NO production in rats provided evidence suggesting that NO production is correlated with erythrocyte glutathione loss. The depletion of glutathione was enhanced during Mg deficiency.

A study of the effects of vitamin E, chloroquine and D-propranolol on red blood cell glutathione levels in Mg-deficient rats reveals that plasma Mg levels are not affected by the three drug treatments but the increase in TBAR content and loss of glutathione are inhibited. The 2.3-fold higher TBAR content seen in red blood cell ghost membranes from the Mg-deficient rats is minimized by vitamin E treatment. A chemical oxyradical system stimulates the loss of glutathione in isolated red blood cells from Mg-sufficient rats. Alpha-tocopherol and D-propranolol exert direct protective effects.

Animals which have low levels of Mg exhibit a specific level of 'inflammatory cytokines' that are not influenced by antioxidant treatment with alpha-tocopherol though the limit of the myocardial lesions are reduced. The extent of circulating cytokines is prominently reduced due to chloroquine treatment in another set of animals lacking Mg. Myocardial lesions also fell to a great extent. Myocardium, which is lacking in Mg, reveals the production of lesions due to the involvement of the inflammatory cytokines. The cytokines induce the generation of free radicals in different cell types.

Author(s): Andrew S Ishizuka; Kirsten E Lyke; Adam DeZure; Andrea A Berry; Thomas L Richie; Floreliz H Mendoza; Mary E Enama; Ingelise J Gordon; Lee-Jah Chang; Uzma N Sarwar; Kathryn [...]