Grade 6 French Immersion Students' Performance on Large-Scale Reading, Writing, and Mathematics Tests: Building Explanations

We analyzed data from Ontario's provincial testing program to ascertain if the reading, writing, and mathematics skills of grade 6 immersion students were comparable to those of regular English program students. Various immersion program designs were taken into account. The analysis confirms the results of earlier program evaluations that any lags in immersion students' achievement in reading, writing, and math disappear by grade 6. We offer two explanations to account for this result. The lag explanation holds that taking reading, writing, and math in French until the end of grade 3 creates a lag in achievement until English is introduced into the curriculum, after which immersion students catch up to regular students' performance. The selection explanation suggests that immersion test performance improves by grade 6 relative to regular English program counterparts because the composition of the grade 6 cohort is more select than that of earlier cohorts.Nous avons analysé des données du programme provincial d'évaluation de l'Ontario dans le but d'évaluer les compétences en lecture, en écriture et en mathématiques des élèves de la sixième année en immersion par rapport à celles d'élèves dans le programme anglais régulier. L'analyse a tenu compte de divers programmes d'immersion. Les résultats confirment ceux d'évaluations de programmes antérieures selon lesquelles les retards que peuvent manifester les élèves en immersion en lecture, en écriture et en mathématiques, disparaissent avant la sixième année. Deux propositions sont présentées pour expliquer ces résultats. Selon l'explication basée sur le retard, le fait de lire, d'écrire et de faire des mathématiques en français jusqu'à la fin de la troisième année provoque un retard dans le rendement des élèves jusqu'à ce que l'anglais soit intégré au programme d'études; c'est à partir de ce moment que les élèves en immersion rattrapent ceux dans les programmes réguliers. L'explication reposant sur l'acheminement veut que l'amélioration dans la performance des élèves en immersion que l'on constate à partir de la sixième soit due au fait que ces élèves représentent une cohorte plus sélective que les précédentes

Exploring power assumptions in the leadership and management debate

Purpose – The purpose of this paper is to take a fresh look at the leadership and management debate through exploring underlying power assumptions in the literature. Design/methodology/approach – The paper is a conceptual discussion that draws on the power-based literature to develop a framework to help conceptually understand leadership in relation to management.Findings – The paper highlights the historically clichéd nature of comments regarding conceptual similarities and differences between leadership and management. The paper draws attention to a problem within this debate – a confusion regarding assumptions of power. As a result the paper brings to the forefront perspectives of management that are of an emergent and non-work perspective which enables the development of a framework of the literature that includes managers “doing” leadership, managers “becoming” leaders, “being” leaders and managers, and leaders “doing” management. The paper goes on to explore the meaning and potential behind each part of the framework and suggests a need to develop an understanding of “doing” leadership and management and “being” managers and leaders through an exploration of “becoming” in organisations.Originality/value – This paper provides a new perspective on the leadership and management or leadership vs management question by introducing a non-work, emergent or personal perspective on management. Furthermore, this paper concludes that whether leadership and management are similar or different is dependent upon which power construct underlies each phenomenon, a consideration that has been neglected in the leadership and management debate for some time

Antarctica\u27s \u27moss forests\u27 are drying and dying

The lush moss beds that grow near East Antarctica\u27s coast are among the only plants that can withstand life on the frozen continent. But our new research shows that these slow-growing plants are changing at a far faster rate than anticipated

Desiccation protects Antarctic mosses from ultraviolet-B induced DNA damage

Antarctic mosses live in a frozen desert, and are characterised by the ability to survive desiccation. They can tolerate multiple desiccation-rehydration events over the summer growing season. As a result of recent ozone depletion, such mosses may also be exposed to ultraviolet-B radiation while desiccated. The ultraviolet-B susceptibility of Antarctic moss species was examined in a laboratory experiment that tested whether desiccated or hydrated mosses accumulated more DNA damage under enhanced ultraviolet-B radiation. Accumulation of cyclobutane pyrimidine dimers and pyrimidine (64) pyrimidone dimers was measured in moss samples collected from the field and then exposed to ultraviolet-B radiation in either a desiccated or hydrated state. Two cosmopolitan species, Ceratodon purpureus (Hedw.) Brid. and Bryum pseudotriquetrum (Hedw.) Gaertn., B.Mey. and Scherb, were protected from DNA damage when desiccated, with accumulation of cyclobutane pyrimidine dimers reduced by at least 60% relative to hydrated moss. The endemic Schistidium antarctici (Cardot) L.I. Savicz and Smirnova accumulated more DNA damage than the other species and desiccation was not protective in this species. The cosmopolitan species remarkable ability to tolerate high ultraviolet-B exposure, especially in the desiccated state, suggests they may be better able to tolerate continued elevated ultraviolet-B radiation than the endemic species

Denervation Causes Fiber Atrophy and Myosin Heavy Chain Co-Expression in Senescent Skeletal Muscle

Although denervation has long been implicated in aging muscle, the degree to which it is causes the fiber atrophy seen in aging muscle is unknown. To address this question, we quantified motoneuron soma counts in the lumbar spinal cord using choline acetyl transferase immunhistochemistry and quantified the size of denervated versus innervated muscle fibers in the gastrocnemius muscle using the in situ expression of the denervation-specific sodium channel, Nav1.5, in young adult (YA) and senescent (SEN) rats. To gain insights into the mechanisms driving myofiber atrophy, we also examined the myofiber expression of the two primary ubiquitin ligases necessary for muscle atrophy (MAFbx, MuRF1). MN soma number in lumbar spinal cord declined 27% between YA (638±34 MNs×mm−1) and SEN (469±13 MNs×mm−1). Nav1.5 positive fibers (1548±70 μm2) were 35% smaller than Nav1.5 negative fibers (2367±78 μm2; P<0.05) in SEN muscle, whereas Nav1.5 negative fibers in SEN were only 7% smaller than fibers in YA (2553±33 μm2; P<0.05) where no Nav1.5 labeling was seen, suggesting denervation is the primary cause of aging myofiber atrophy. Nav1.5 positive fibers had higher levels of MAFbx and MuRF1 (P<0.05), consistent with involvement of the proteasome proteolytic pathway in the atrophy of denervated muscle fibers in aging muscle. In summary, our study provides the first quantitative assessment of the contribution of denervation to myofiber atrophy in aging muscle, suggesting it explains the majority of the atrophy we observed. This striking result suggests a renewed focus should be placed on denervation in seeking understanding of the causes of and treatments for aging muscle atrophy

Moss species on the move in East Antarctic terrestrial communities

Antarctica has experienced major changes in temperature, wind speed and stratospheric ozone levels over the last 50 years. Whilst West Antarctica and the peninsula showed rapid warming and associated ecosystem change, East Antarctica appeared to be little impacted by climate warming, thus biological changes were predicted to be relatively slow. Detecting the biological effects of Antarctic climate change has also been hindered by the paucity of long-term data sets, particularly for organisms that have been exposed to these changes throughout their lives. We monitored vegetation communities in the Windmill Islands, East Antarctica from 2000 to 2014 and found significant changes in moss species composition. In addition, we have shown that radiocarbon signals preserved along shoots of the dominant Antarctic moss flora can be used to determine accurate growth rates over a period of several decades, allowing us to explore the influence of environmental variables on growth. Carbon stable isotopic measurements suggest that the observed effects of climate variation on growth are mediated through changes in water availability and most likely linked to the more positive phase of the Southern Annular Mode and changing westerly wind patterns. For cold remote locations like Antarctica, where climate records are limited and of relatively short duration, this illustrates that mosses can act as microclimate proxies and have the potential to increase our knowledge of coastal Antarctic climate change

Glyconanoparticles for colorimetric bioassays

Carbohydrate molecules are involved in many of the cellular processes that are important for life. By combining the specific analyte targeting of carbohydrates with the multivalent structure and change of solution colour as a consequence of plasmonic interactions with the aggregation of metal nanoparticles, glyconanoparticles have been used extensively for the development of bioanalytical assays. The noble metals used to create the nanocore, the methodologies used to assemble the carbohydrates on the nanoparticle surface, the carbohydrate chosen for each specific target, the length of the tether that separates the carbohydrate from the nanocore and the density of carbohydrates on the surface all impact on the structural formation of metal based glyconanoparticles. This tutorial review highlights these key components, which directly impact on the selectivity and sensitivity of the developed bioassay, for the colorimetric detection of lectins, toxins and viruses

Dendritic glycopolymers based on dendritic polyamine scaffolds: view on their synthetic approaches, characteristics and potential for biomedical applications

In this review we highlight the potential for biomedical applications of dendritic glycopolymers based on polyamine scaffolds. The complex interplay of the molecular characteristics of the dendritic architectures and their specific interactions with various (bio)molecules are elucidated with various examples. A special role of the individual sugar units attached to the dendritic scaffolds and their density is identified, which govern ionic and H-bond interactions, and biological targeting, but to a large extent are also responsible for the significantly reduced toxicity of the dendritic glycopolymers compared to their polyamine scaffolds. Thus, the application of dendritic glycopolymers in drug delivery systems for gene transfection but also as therapeutics in neurodegenerative diseases has great promisePublikacja w ramach programu Royal Society of Chemistry "Gold for Gold" 2014 finansowanego przez Uniwersytet Łódzk