Relationship between early development of spelling and reading

The research reported in this thesis examined the relationship between beginning spelling and reading. More specifically, it focussed on the relationship between the development of early reading and spelling in a context where the approach to early reading instruction includes systematic phonological awareness and decoding instruction. A critical assumption made by proponents of developmental early literacy models is that transfer of skills and knowledge from reading to spelling will occur spontaneously and without formal instruction (Frith, 1980). By contrast instruction-centred approaches make the assumption that there are critical pre-requisite skills that can and should be taught explicitly (Carnine, Silbert & Kameenui, 1997). The difference between these approaches is highlighted in the treatment of invented spelling, a popular activity in Western Australian junior primary classes. A series of studies was undertaken to examine the effect on invented and standard spelling performance of teaching Year 1 children phonological awareness and the strategy of sounding out words. Data were gathered from a range of settings using different research tools. The relationship between phonological awareness and beginning reading and spelling performance was explored initially through a single case study. A post-hoc study was then undertaken with a cohort of students who had received systematic decoding instruction to examine whether proficiency in the decoding of nonwords was related to spelling performance. This permitted an analysis of common sub-skills of decoding and encoding. In the main study the effect on different aspects of reading and spelling performance of using Let\u27s Decode, an approach that includes explicit phonological awareness and systematic decoding instruction, was investigated. In addition, an analysis was made of whether students who received explicit instruction in skills known to contribute to beginning reading and spelling produced superior invented spelling samples. A qualitative analysis was made of the. pre and post invented spelling tests of two pairs of students from the control and intervention groups matched on invented spelling and phonological awareness skills at the beginning of the year, and re tested at the end of Year 1. The final research question involved a single-subject research design to examine the effect of explicit instruction in isolating phonemes in words and prompts to \u27listen for sounds\u27 prior to, and during, the process of spelling words. The single case study revealed a child who was regarded as a competent speller and reader but who could only read words in a familiar context and who had developed a strategy for spelling words based on copying an adult model. This was interpreted as evidence supporting the need for phonological awareness instruction as a pre-requisite for spelling. The post-hoc analysis of a class of students who had received systematic decoding instruction showed that no student classified as a \u27good decoder\u27 could also be classified as a \u27poor speller\u27. This result was considered evidence of a strong link between the phonological knowledge that is required to decode and the role of alphabetic knowledge in spelling. The main study revealed phonological awareness and systematic decoding instruction was associated with superior invented and conventional spelling and reading performance on all reading and spelling measures. Of particular importance was the finding that students who commenced the study with very weak phonological awareness and who subsequently received systematic phonological and decoding instruction showed greater gains in invented spelling than matched students in the control condition. The single subject design showed the effectiveness of phonological awareness individualised instruction on invented spelling for weak students from both intervention and control conditions. It was concluded that the ability to invent spelling is improved when students receive explicit instruction in phonological awareness and systematic decoding but that some students, namely those with persistent weakness in phonological awareness, also require explicit prompts to apply their alphabetic knowledge to spelling words. The implications for instruction of these findings are discussed

Current and potential geographical distribution of Platymeris biguttatus (Linnaeus, 1767) with description of nymphs

Background: The description of Platymeris biguttatus (Linnaeus 1767) nymphal instars as well as the prediction of the potentially suitable ecological niche was the main goal of this study. Our research was based on 258 specimens of P. biguttatus species of museum collections. A set of 23 environmental predictor variables covering Africa was used at ecological niche modeling - a method performed using the Maxent software to prepare potential distribution maps for this species. Results: The results suggested the most suitable areas seen as potentially suitable ecological niche for P. biguttatus in Africa. A jackknife test showed that temperature seasonality and percentage of tree cover were among the most important environmental variables affecting the distribution of the species. The analysis of climate preferences shows that most of the potentially suitable niches for this species were located in the area of tropical savanna climate, with a small participation of tree vegetation. Conclusions: P. biguttatus was only known to be widely distributed in the tropical part of continental Africa. Thanks to the ecological niche modeling methods and the museum data on the occurrence of the species, we introduced new information about potentially suitable ecological niches and the possible range of distribution

A Gap Analysis Methodology for Collecting Crop Genepools: A Case Study with Phaseolus Beans

Background The wild relatives of crops represent a major source of valuable traits for crop improvement. These resources are threatened by habitat destruction, land use changes, and other factors, requiring their urgent collection and long-term availability for research and breeding from ex situ collections. We propose a method to identify gaps in ex situ collections (i.e. gap analysis) of crop wild relatives as a means to guide efficient and effective collecting activities. Methodology/Principal Findings The methodology prioritizes among taxa based on a combination of sampling, geographic, and environmental gaps. We apply the gap analysis methodology to wild taxa of the Phaseolus genepool. Of 85 taxa, 48 (56.5%) are assigned high priority for collecting due to lack of, or under-representation, in genebanks, 17 taxa are given medium priority for collecting, 15 low priority, and 5 species are assessed as adequately represented in ex situ collections. Gap “hotspots”, representing priority target areas for collecting, are concentrated in central Mexico, although the narrow endemic nature of a suite of priority species adds a number of specific additional regions to spatial collecting priorities. Conclusions/Significance Results of the gap analysis method mostly align very well with expert opinion of gaps in ex situ collections, with only a few exceptions. A more detailed prioritization of taxa and geographic areas for collection can be achieved by including in the analysis predictive threat factors, such as climate change or habitat destruction, or by adding additional prioritization filters, such as the degree of relatedness to cultivated species (i.e. ease of use in crop breeding). Furthermore, results for multiple crop genepools may be overlaid, which would allow a global analysis of gaps in ex situ collections of the world's plant genetic resource

Which Factors Determine Spatial Segregation in the South American Opossums (Didelphis aurita and D. albiventris)? An Ecological Niche Modelling and Geometric Morphometrics Approach

Didelphis albiventris and D. aurita are Neotropical marsupials that share a unique evolutionary history and both are largely distributed throughout South America, being primarily allopatric throughout their ranges. In the Araucaria moist forest of Southern Brazil these species are sympatric and they might potentially compete having similar ecology. For this reason, they are ideal biological models to address questions about ecological character displacement and how closely related species might share their geographic space. Little is known about how two morphologically similar species of marsupials may affect each other through competition, if by competitive exclusion and competitive release. We combined ecological niche modeling and geometric morphometrics to explore the possible effects of competition on their distributional ranges and skull morphology. Ecological niche modeling was used to predict their potential distribution and this method enabled us to identify a case of biotic exclusion where the habit generalist D. albiventris is excluded by the presence of the specialist D. aurita. The morphometric analyses show that a degree of shape discrimination occurs between the species, strengthened by allometric differences, which possibly allowed them to occupy marginally different feeding niches supplemented by behavioral shift in contact areas. Overlap in skull morphology is shown between sympatric and allopatric specimens and a significant, but weak, shift in shape occurs only in D. aurita in sympatric areas. This could be a residual evidence of a higher past competition between both species, when contact zones were possibly larger than today. Therefore, the specialist D. aurita acts a biotic barrier to D. albiventris when niche diversity is not available for coexistence. On the other hand, when there is niche diversification (e.g. habitat mosaic), both species are capable to coexist with a minimal competitive effect on the morphology of D. aurita

Modeling Species Distributions from Heterogeneous Data for the Biogeographic Regionalization of the European Bryophyte Flora

The definition of biogeographic regions provides a fundamental framework for a range of basic and applied questions in biogeography, evolutionary biology, systematics and conservation. Previous research suggested that environmental forcing results in highly congruent regionalization patterns across taxa, but that the size and number of regions depends on the dispersal ability of the taxa considered. We produced a biogeographic regionalization of European bryophytes and hypothesized that (1) regions defined for bryophytes would differ from those defined for other taxa due to the highly specific eco-physiology of the group and (2) their high dispersal ability would result in the resolution of few, large regions. Species distributions were recorded using 10,000 km2 MGRS pixels. Because of the lack of data across large portions of the area, species distribution models employing macroclimatic variables as predictors were used to determine the potential composition of empty pixels. K-means clustering analyses of the pixels based on their potential species composition were employed to define biogeographic regions. The optimal number of regions was determined by v-fold cross-validation and Moran's I statistic. The spatial congruence of the regions identified from their potential bryophyte assemblages with large-scale vegetation patterns is at odds with our primary hypothesis. This reinforces the notion that post-glacial migration patterns might have been much more similar in bryophytes and vascular plants than previously thought. The substantially lower optimal number of clusters and the absence of nested patterns within the main biogeographic regions, as compared to identical analyses in vascular plants, support our second hypothesis. The modelling approach implemented here is, however, based on many assumptions that are discussed but can only be tested when additional data on species distributions become available, highlighting the substantial importance of developing integrated mapping projects for all taxa in key biogeographically areas of Europe, and the Mediterranean peninsulas in particular. © 2013 Mateo et al

Future climate change vulnerability of endemic island mammals

International audienceDespite their high vulnerability, insular ecosystems have been largely ignored in climate change assessments, and when they are investigated, studies tend to focus on exposure to threats instead of vulnerability. The present study examines climate change vulnerability of islands, focusing on endemic mammals and by 2050 (RCPs 6.0 and 8.5), using trait-based and quantitative-vulnerability frameworks that take into account exposure, sensitivity, and adaptive capacity. Our results suggest that all islands and archipelagos show a certain level of vulnerability to future climate change, that is typically more important in Pacific Ocean ones. Among the drivers of vulnerability to climate change, exposure was rarely the main one and did not explain the pattern of vulnerability. In addition, endemic mammals with long generation lengths and high dietary specializations are predicted to be the most vulnerable to climate change. Our findings highlight the importance of exploring islands vulnerability to identify the highest climate change impacts and to avoid the extinction of unique biodiversity