Paléophytogéographie et paléoclimats postglaciaires dans l’ouest du Bas-Saint-Laurent, Québec

L'analyse pollinique des sédiments de quatre lacs du Bas-Saint-Laurent et de la Côte-du-Sud permet de retracer l'existence d'une phase initiale de toundra s'étendant sur une durée estimée à 500-1000 ans, après à la déglaciation. Cette toundra montre un développement progressif à partir d'un quasi-désert jusqu'à un stade arbustif à bouleau glanduleux, en passant par un stade herbacé riche en plantes arctiques-alpines dont la présence est confirmée par l'analyse macrofossile. L'accumulation organique dans les lacs ne survient que vers 9500-9200 BP, soit plus de 2000 ans après la déglaciation, et correspond à l'arrivée des premiers arbres, d'après les macrorestes. Le tardiglaciaire régional paraît donc avoir été climatiquement très rigoureux par rapport aux régions sises au sud-ouest et au sud, dans les Appalaches. Les forêts sont restées ouvertes jusque vers 8000 BP, constituées surtout de l'épinette noire, des peupliers, du mélèze et du bouleau blanc. La zone pollinique correspondante est dominée par l'aulne crispé, qui a dû jouer un rôle important dans le couvert végétal durant une période caractérisée par une forte incidence des feux. Par la suite, la végétation moderne s'est établie, soit une mosaïque de sapinières et d'érablières avec sensiblement les mêmes séquences physiographiques et les mêmes gradients phytogéographiques régionaux que ceux actuellement constatés dans ce secteur des Appalaches. Les cédrières tourbeuses et les sapinières humides à thuya répandues actuellement dans les basses terres estuariennes et à la marge nord du plateau appalachien ne se sont toutefois développées que vers 3600 ans avant l'actuel. L'Optimum climatique holocene n'est clairement marqué que par une plus grande abondance du pin blanc de 7000 à 3600 ans BP, notamment à la marge nord du plateau appalachien.Postglacial paleophytogeography and paleoclimates in the western part of the Lower Saint Lawrence River region, Québec. Pollen analysis of the sediments of four lakes in the Lower Saint Lawrence River region, north of Maine, shows that tundra vegetation existed during an estimated period of 500 to 1000 years following ice retreat. Progressive development of the tundra from a quasi-desert to a shrub stage with dwarf birch, through an herb stage rich in arctic-alpine taxa is confirmed by macrofossil analysis. Organic sedimentation in the lakes started only around 9500-9200 BP, that is to say more than 2000 years after ice retreat, and is coincident with the arrival of the first trees (macrofossils) in the area. The regional late-glacial climate was thus apparently very harsh, compared to the Appalachian regions located to the south and southwest. Black spruce, the poplars, larch and white birch comprised the forests which remained open until around 8000 BP. The corresponding pollen zone is dominated by green alder which played a major role in the plant cover during a period characterized by a great incidence of fire. Afterwards, the modern vegetation developed, corresponding to a mosaic of fir and maple communities with physiographic sequences and regional phytogeographic gradients similar to those present today within this section of the Appalachian range. Eastern white cedar, which nowadays occupies the wet or boggy sites of the estuarine lowlands and of the northern margin of the Appalachian plateau, whether in pure stands or with balsam fir, began to increase by 3600 BP. The Holocene Climatic Optimum is clearly marked in the study area only by a greater abundance of white pine, especially at the northern margin of the Appalachian plateau between 7000 abd 3600 BP.Mit der Pollenanalyse der Sedimente von vier Seen IaBt sich der Beginn einer Tundra-Phase nachweisen, die nach der Enteisung schâtzungsweise 500-1000 Jahre dauerte. Diese Tundra zeigt eine progressive Entwicklung, ausgehend von einer Quasi-wiiste bis hin zu einem Buschstadium mit Zwergbirke uber ein Pflanzenstadium, das reich an arktisch-alpinen Pflanzen war, deren Vorkommen durch die makrofossile Analyse bestàtigt wird. Die organische Sedimentierung in den Seen tritt erst gegen 9500-9200 Jahre v.u.Z. auf, d.h. uber 2000 Jahre nach Enteisung, und sie entspricht der Ankunft der ers-ten Baume, den Makroresten nach zu schlieBen. Das régionale Spâtglazial scheint demnach klimatisch sehr rauh gewesen zu sein im Vergleich zu den sudwestlich und sudlich gelegenen Gebieten in den Appa-lachen. Die Wàlder blieben bis gegen 8000 v.u.Z. offen und bestanden vor allem aus Schwarztanne, Pappel, Làrche und WeiB-birke. Das entsprechende Pollengebiet ist dominiert von Grunerle, welche eine wichtige RoIIe in der Pflanzendecke gespielt haben mu(3, in einer Zeit, in der gehâuft Brànde auftraten. In der Folgezeit hat sich die moderne Vegetation angesiedelt, d.h. ein Mosaik von Tannen- und Ahornwàldern. Indessen haben die torfhaltigen Zedernwàlder und die feuch-ten Thuja-Tannenwâlder, die gegenwartig in den Mundungs-Niederungen und am Nord-saum des Appalachenplateaus verbreitet sind, sich erst gegen 3600 v.u.Z. entwickelt. Das KIimatische Optimum im Holozan ist nur durch eine grôBere FuIIe der WeiBtanne von 7000 bis 3600 Jahre v.u.Z. klar gekennzeichnet

Cascading the use of Web 2.0 technology in secondary schools in the United Kingdom: identifying the barriers beyond pre-service training

This paper reports on research that took place at Nottingham Trent University and Sheffield Hallam University, United Kingdom, over two years. The research focuses on the use of Web 2.0 technology, specifically web logs, with pre-service teachers, both during their university programme and the first year of teaching as full-time newly qualified teachers (NQTs). The purpose of this research was to add a developing body of knowledge by identifying whether technology used by pre-service teachers during their training course can be cascaded into their practice once qualified. Key findings identify a number of enablers and barriers to cascading technology in the classroom; these include curriculum time, pupil skills and support. The research concludes that early professional support and development should be on-going and assumptions about new teachers as champions of cascading innovative use of Web 2 technologies into their practice as NQTs may be over optimisti

How leadership moments are enacted within a strict hierarchy: The case of kitchen brigades in Haute Cuisine restaurants

This paper employs a strong process approach to leadership – one that focuses on leadership moments in action – to explore how collaborative leadership emerges within a hierarchical context. Drawing on observation in three Haute Cuisine restaurant kitchen brigades – highly hierarchical teams that deal with intense time pressures – we document empirically in the ongoing flow of experience how leadership moments reorient collective action as a response to an unstable environment. Moreover, we show how collaborative leadership emerges from a hierarchical structure, counterintuitively, during the most critical period of the service. Our contribution is twofold. We offer a novel conceptualization of the emergence of plural leadership within a hierarchical context, one that highlights the capacity to reframe the way of working together during the most critical moments of an unfolding situation. In addition, our work contributes to the strong process approach to leadership through the methodology adopted: rather than exploring how turning points are discursively enacted, we focus on these as manifested in action and in the non-verbal aspects displayed at such moments

Plant invasions, generalist herbivores, and novel defense weapons

One commonly accepted mechanism for biological invasions is that species, after introduction to a new region, leave behind their natural enemies and therefore increase in distribution and abundance. However, which enemies are escaped remains unclear. Escape from specialist invertebrate herbivores has been examined in detail, but despite the profound effects of generalist herbivores in natural communities their potential to control invasive species is poorly understood. We carried out parallel laboratory feeding bioassays with generalist invertebrate herbivores from the native (Europe) and from the introduced (North America) range using native and nonnative tetraploid populations of the invasive spotted knapweed, Centaurea stoebe. We found that the growth of North American generalist herbivores was far lower when feeding on C. stoebe than the growth of European generalists. In contrast, North American and European generalists grew equally well on European and North American tetraploid C. stoebe plants, lending no support for an evolutionary change in resistance of North American tetraploid C. stoebe populations against generalist herbivores. These results suggest that biogeographical differences in the response of generalist herbivores to novel plant species have the potential to affect plant invasions

Measuring academic research impact: creating a citation profile using the conceptual framework for implementation fidelity as a case study

The “citation score” remains the most commonly-used measure of academic impact, but is also viewed as practically and conceptually limited. The aim of this case study was to test the feasibility of creating a “citation profile” for a single, frequently-cited methods paper, the author’s own publication on the conceptual framework for implementation fidelity. This was a proof-of-concept study that involved an analysis of the citations of a single publication. This analysis involved identifying all citing publications and recording, not only how many times the key paper was cited within each citing publication, but also within which sections of that publication (e.g. Background, Methods, Results etc.). Level of impact could be categorised as high, moderate or low. The key paper had been cited more than 400 times and had a high impact in 25 % of publications based on citation frequency within publications, i.e. the key paper was cited three or more times; and a low impact in 58 % of citing publications, i.e. the key paper was cited just once. There were 41 “high impact” publications based on location of the citations, of which 35 (85 %) were also categorised as high impact by frequency. These results suggest that it is both possible and straightforward to categorise the level of impact of a key paper based on its “citation profile”, i.e., the frequency with which the paper is cited within citing publications, thus adding depth and value to the citation metric

Smelting conditions and smelting products: Experimental insights into the development of iron bloomery furnaces

The material record for bloomery furnaces in Iron Age and Roman Britain is fragmentary and, because of this paucity of evidence, the reconstruction of the ceramic structures used in iron production is difficult. Experiments have nevertheless been carried out to explore the working parameters and efficiency of iron smelting in bowl furnaces (small structures with little structure above ground level, interior measuring about 30 cm in height) (Craddock, 1995; Girbal, 2013) and shaft furnaces (height c.1m) (Smith, 2013; Crew, 2013; Doonan and Dungworth, 2013; Tylecote and Merkel, 1985; Tylecote and Wynne, 1958). These experiments aimed to clarify which furnace is more efficient for iron smelting and therefore what method was most likely used in Iron Age and Roman Britain. It is theorised that iron smelting furnaces developed from bowl structures to shaft structures over time, as smelters sought furnaces which could reach higher temperatures and create more reducing atmospheres (Dungworth 2013; Tylecote and Merkel, 1985; Tylecote and Wynne, 1958). These experiments suggest that the shaft furnace was used as it could meet these requirements. This study looks at the working conditions of a shaft furnace at an intermediary height - between that of a bowl furnace and of a shaft furnace - in order to understand its working parameters and to consequently better understand the progression from a bowl to a 1m high shaft structure

Education and service : how theories can help in understanding tensions

Acknowledgements: our thanks to Ayelet Kuper for a helpfuldiscussion about the possible application of discourseanalysis to service–training tensionsPeer reviewedPostprin

Wanting to become PE teachers in Spain: connections between previous experiences and particular beliefs about school Physical Education and the development of professional teacher identities

Physical Education (PE) teachers have previous experiences that both shape their particular beliefs about the role and purpose of this school subject as well as their pedagogical practice. The present study aims to examine and deepen our knowledge of future Spanish PE teachers’ previous experiences of and beliefs about PE that condition their pedagogical practice and intentionality within this school subject. The data reported on in this paper were generated through questionnaires, life-history stories and semi-structured interviews with 24 initial teacher education students in the second year of a degree specialising in PE at a Spanish university. The data was analysed using content and narrative (thematic) analysis. The students, far from being tabula rasa, in their responses show how their previous socialisation period, their subjectivities and identities constitute particular beliefs about PE teaching. More specifically, the results reveal four key themes in the student teachers’ experiences and beliefs that represent four different factors influencing future PE teacher identities: (1) ‘Sport’; (2) ‘PE for health’; (3) ‘A focus on pedagogy’; and (4) ‘A critical orientation’. In conclusion, the study reaffirms the need for further reflection on how previous experiences and beliefs influence the development of professional teacher identities as part of initial teacher education in PE

Moving beyond physical education subject knowledge to develop knowledgeable teachers of the subject

All knowledge is socially constructed, including physical education teachers’ knowledge of their subject. It is acquired from other people either formally and deliberately (e.g. by being taught) or informally and casually (e.g. by interacting with physical education teachers or playing in a sports team). The social aspects of learning appear to be particularly strong in physical education. This has implications for the development of knowledge for teaching, with trainee teachers focusing on the development of subject, and particularly content, knowledge. Focusing on subject knowledge reinforces a traditional view of physical education as it is, not as it might be to meet the needs of young people today. It is argued that attention needs to be given not only to the knowledge, skills and competencies that trainee teachers ought to develop but also to the social aspects of their learning and development and the context in which they learn. Attention also needs to be given to how the ability to think critically can be developed so that trainee teachers can become reflective practitioners able to challenge and, where appropriate, change the teaching of the subject. Only by doing this can the particularly strong socialisation which shapes the values and beliefs of physical education teachers begin to be challenged. However, as the process of developing knowledgeable teachers is ongoing it is also necessary to look beyond teacher training to continuing professional development

Moving beyond physical education subject knowledge to develop knowledgeable teachers of the subject

All knowledge is socially constructed, including physical education teachers’ knowledge of their subject. It is acquired from other people either formally and deliberately (e.g. by being taught) or informally and casually (e.g. by interacting with physical education teachers or playing in a sports team). The social aspects of learning appear to be particularly strong in physical education. This has implications for the development of knowledge for teaching, with trainee teachers focusing on the development of subject, and particularly content, knowledge. Focusing on subject knowledge reinforces a traditional view of physical education as it is, not as it might be to meet the needs of young people today. It is argued that attention needs to be given not only to the knowledge, skills and competencies that trainee teachers ought to develop but also to the social aspects of their learning and development and the context in which they learn. Attention also needs to be given to how the ability to think critically can be developed so that trainee teachers can become reflective practitioners able to challenge and, where appropriate, change the teaching of the subject. Only by doing this can the particularly strong socialisation which shapes the values and beliefs of physical education teachers begin to be challenged. However, as the process of developing knowledgeable teachers is ongoing it is also necessary to look beyond teacher training to continuing professional development