71 research outputs found

    Inclusive School Community: Why is it so Complex?

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    This paper addresses the question: why is it so hard for school communities to respond to diversity in learners, staff and parents in inclusive ways? The authors draw on theory and recent professional experience in Queensland, Australia, to offer four guiding principles that address traditional assumptions about learning that result in inequality of opportunity and outcomes for students. The authors suggest these principles to support the development of a more inclusive school community: (1) develop a learning community incorporating a critical friend; (2) value and collaborate with parents and the broader community; (3) engage students as citizens in school review and develop¬ment; and (4) support teachers’ critical engagement with inclusive ideals and practices. The authors describe how the principles can work in concert in a school community

    Coping with potential bi-parental inbreeding: limited pollen and seed dispersal and large genets in the dioecious marine angiosperm Thalassia testudinum

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    The high prevalence of dioecy in marine angiosperms or seagrasses (>50% of all species) is thought to enforce cross-fertilization. However, seagrasses are clonal plants, and they may still be subject to sibling-mating or bi-parental inbreeding if the genetic neighborhood is smaller than the size of the genets. We tested this by determining the genetic neighborhoods of the dioecious seagrass Thalassia testudinum at two sites (Back-Reef and Mid-Lagoon) in Puerto Morelos Reef Lagoon, Mexico, by measuring dispersal of pollen and seeds in situ, and by finescale spatial autocorrelation analysis with eight polymorphic microsatellite DNA markers. Prevalence of inbreeding was verified by estimating pairwise kinship coefficients; and by analysing the genotypes of seedlings grown from seeds in mesocosms. Average dispersal of pollen was 0.3–1.6 m (max. 4.8 m) and of seeds was 0.3–0.4 m (max. 1.8 m), resulting in a neighborhood area of 7.4 m² (range 3.4–11.4 m²) at Back-Reef and 1.9 (range 1.87–1.92 m²) at Mid-Lagoon. Neighborhood area (Na) derived from spatial autocorrelation was 0.1–20.5 m² at Back-Reef and 0.1–16.9 m² at Mid-Lagoon. Maximal extensions of the genets, in 19 9 30 m plots, were 19.2 m (median 7.5 m) and 10.8 m (median 4.8 m) at Back-Reef and Mid-Lagoon. There was no indication of deficit or excess of heterozygotes nor were coefficients of inbreeding (Fis) significant. The seedlings did not show statistically significant deficit of heterozygotes (except for 1 locus at Back-Reef). Contrary to our expectations, we did not find evidence of bi-parental inbreeding in this dioecious seagrass with large genets but small genetic neighborhoods. Proposed mechanisms to avoid bi-parental inbreeding are possible selection against homozygotes during fecundation or ovule development. Additionally, the genets grew highly dispersed (aggregation index Ac was 0.09 and 0.10 for Back-Reef and Mid-Lagoon, respectively); such highly dispersed guerrilla-like clonal growth form likely increases the probability of crossing between different potentially unrelated genets.Brigitta Ine Van Tussenbroek, Tania Valdivia-Carrillo, Irene Teresa Rodríguez-Virgen, Sylvia Nashieli Marisela Sanabria-Alcaraz, Karina Jiménez-Duran, Kor Jent Van Dijk, Guadalupe Judith Marquez-Guzmá

    Aboriginal and Torres Strait Islander Suicide in Context

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    Aboriginal and Torres Strait Islander suicide has been an issue of national public health and mental health concern for only one decade, having increased dramatically from levels that were very low in the late 1980s to levels of young adult male suicide that are now substantially higher than for the non-indigenous population. In this review the authors socially and historically contextualize these changes, identifying the causal frameworks adopted in developing interventions, and present an explanation in narrative and pictorial form that draws on critical family-centered trauma

    Ribosomal RNA of Hyacinthus orientalis L. female gametophyte cells before and after fertilization

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    The nucleolar activity of Hyacinthus orientalis L. embryo sac cells was investigated. The distributions of nascent pre-rRNA (ITS1), 26S rRNA and of the 5S rRNA and U3 snoRNA were determined using fluorescence in situ hybridization (FISH). Our results indicated the different rRNA metabolism of the H. orientalis female gametophyte cells before and after fertilization. In the target cells for the male gamete, i.e., the egg cell and the central cell whose activity is silenced in the mature embryo sac (Pięciński et al. in Sex Plant Reprod 21:247–257, 2008; Niedojadło et al. in Planta doi:10.1007/s00425-012-1599-9, 2011), rRNA metabolism is directed at the accumulation of rRNPs in the cytoplasm and immature transcripts in the nucleolus. In both cells, fertilization initiates the maturation of the maternal pre-rRNA and the expression of zygotic rDNA. The resumption of rRNA transcription observed in the hyacinth zygote indicates that in plants, there is a different mechanism for the regulation of RNA Pol I activity than in animals. In synergids and antipodal cells, which have somatic functions, the nucleolar activity is correlated with the metabolic activity of these cells and changes in successive stages of embryo sac development

    Effect of Extended Mat Open Assembly Time on Properties of OSB Bonded With PMDI

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    In this study, the effect of increasing mat open assembly time on the strength properties of oriented strandboards bonded with polymeric methylene diphenol di-isocyanate (pMDI) resin was examined. Isocyanates are more sensitive to open assembly times than other resin systems such as phenol formaldehyde (PF), and the storage capacity of pMDI-blended wood furnish is believed to be no more than about 5 h. On the other hand, previous research works on bonding of wood elements with pMDI allude to the growth of an interpenetrating network (IPN) of cross-linked polyurea as being responsible for the high bonding capacity with pMDI and that this is enhanced with long pre-cure times (greater than 10-15 h). There was no evidence that this effect enhances the strength of OSB made from shortleaf pine, as boards pressed after a delay of 10 or more hours after blending were significantly lower in internal bond (IB) strength than those pressed within half an hour of blending. However, after a reduction of approximately 28% between 0 and 10 h, IB remained relatively stable with open assembly times up to 18 h, suggesting the potential for recycling such strands by partial substitution of them with freshly blended strands. The discrepancy between our findings and the pMDI bonding theory based on previous small-scale laboratory experiments was thought to have arisen from differences in resin distribution on the strands due to their different methods of application, and the cure temperature and moisture conditions in the core of boards being sub-optimal for the formation of an extensive network of fully cross-linked polyurea

    The use of seawater-neutralised bauxite refinery residues (red mud) in environmental remediation programs

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    Seawater-neutralised bauxite refinery residues (red mud) have a very high trace metal trapping capacity (>1000 meq/kg), and a high acid neutralisation capacity (≈3.5 moles/kg) that is due to an abundance of amorphous and finely crystalline phases that form weak bases; trace metals bound to the red mud can not be readily leached off. These properties make the seawater-neutralised red mud suitable for treating acid mine drainage, tailings pond waters, and acid sulphate soils; there are also other potential uses. The red mud can be mixed with contaminated liquids or solids, or used to form permeable subsurface barriers that will not impede subsurface water flow but will neutralise any acid and strip trace metals from contaminated water before it reaches natural waterways. This paper describes the properties of seawater-neutralised red mud and the results of trials involving its use in environmental management and remediation applications
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