54 resultados para FINE
Resumo:
Diets of the pipefish Stigmatopora nigra were analysed to determine if food availability was causing S. nigra to distribute according to habitat edge effects. Gut analysis found little difference in the diets of S. nigra at the edge and interior of seagrass patches, regardless of time of day or season. Fish diets did, however, vary with seagrass density: S. nigra in denser seagrass consumed more harpacticoid copepods and fewer planktonic copepods. The lack of difference in prey eaten by S. nigra at the edge and interior of patches suggests either that food was not determining S. nigra distribution patterns within patches or that differences in fish densities across patches meant that relative fish–prey densities were similar at edge and interior positions. Alternatively, any edge effects in diet might be masked by gradients in seagrass structure.
Resumo:
Understanding how habitat fragmentation affects population processes (e.g. dispersal) at different spatial scales is of critical importance to conservation. We assessed the effects of habitat fragmentation on dispersal and regional and fine-scale population structure in a currently widespread and common cooperatively breeding bird species found across south-eastern Australia, the superb fairy-wren Malurus cyaneus. Despite its relative abundance and classification as an urban tolerant species, the superb fairy-wren has declined disproportionately from low tree-cover agricultural landscapes across the Box-Ironbark region of north-central Victoria, Australia. Loss of genetic connectivity and disruption to its complex social system may be associated with the decline of this species from apparently suitable habitat in landscapes with low levels of tree cover. To assess whether reduced structural connectivity has had negative consequences for genetic connectivity in the superb fairy-wren, we used a landscape-scale approach to compare patterns of genetic diversity and gene flow at large (landscape/regional) and fine (site-level) spatial scales. In addition, using genetic distances, for each sex, we tested landscape models of decreased dispersal through treeless areas (isolation-by-resistance) while controlling for the effect of isolation-by-distance. Landscape models indicated that larger-scale gene flow across the Box-Ironbark region was constrained by distance rather than by lack of structural connectivity. Nonetheless, a pattern of isolation-by-resistance for males (the less-dispersive sex) and lower genetic diversity and higher genetic similarity within sites in low-cover fragmented landscapes indicated disruption to fine-scale gene flow mechanisms and/or mating systems. Although loss of structural connectivity did not appear to impede gene flow at larger spatial scales, fragmentation appeared to affect fine-scale population processes (e.g. local gene flow mechanisms and/or mating systems) adversely and may contribute to the decline of superb fairy-wrens in fragmented landscapes in the Box-Ironbark region. © 2012 British Ecological Society.
Resumo:
Novice learners need to have simplified explanations because they are unable to understand fuller, more-involved explanations. However, there is a dangerously thin line between simplified explanations and over-simplified erroneous explanations, which lead to later misunderstandings and misconceptions. It is harder to unlearn misunderstandings and misconceptions, than to learn something new ab initio.
It is virtually impossible for any teacher to know everything that students will need for future study and careers, as each subject will lead to a myriad of pathways. For example, in my undergraduate 1st year class, students will go into numerous majors across more than 16 degree programs ranging from arts to zoology and from engineering to food-and-nutrition.
The present subject is part of the foundation for many possible pathways, but it is extremely difficult for a single teacher to know about all of them, or to know about specialist topics developed in later years. Thus, to prevent over-simplifications and misconceptions, there is need for partnerships between the teacher in the present subject and employers, researchers, industrial scientists and teachers from later in the educational and career pathway. These vertical partnerships or advisory groups can help teachers to access information from later in the pathway, so that these teachers have a greater appreciation of the subtleties and the whys of what they teach.
Not everything is in the textbook. Indeed, this is implicit in the new National Curriculum, in which students have to learn about the culture of science as part of Science as a Human Endeavour (SHE). We need more partnership and cooperation between the teachers, who are pedagogy specialists, and researchers and industry scientists, who are the content knowledge specialists.
Resumo:
Graphene, multi-wall carbon nanotube (MWCNT) and fine boron nitride (BN) particles were separately applied with a resin onto a cotton fabric, and the effect of the thin composite coatings on the thermal conductive property, air permeability, wettability and color appearance of the cotton fabric was examined. The existence of the fillers within the coating layer increased the thermal conductivity of the coated cotton fabric. At the same coating content, the increase in fabric thermal conductivity was in the order of graphene > BN > MWCNT, ranging from 132 % to 842 % (based on pure cotton fabric). The coating led to 73 %, 69 % and 64 % reduction in air permeability when it respectively contained 50.0 wt% graphene, BN and MWCNTs. The graphene and MWCNT treated fabrics had a black appearance, but the coating had almost no influence on the fabric hydrophilicity. The BN coating made cotton fabric surface hydrophobic, with little change in fabric color.
