Habitat Use by Greater Snow Geese During the Brood-Rearing Period

Observations of habitat use by the Greater Snow Goose (Anser caerulescens atlanticus) were conducted at Jungersen Bay, northern Baffin Island, from 27 July-17 August 1981. Density of geese using the study area was estimated at 425 birds/sq km. The average of 2.8 young per family did not change during our study. Non-breeding geese were first observed in flight on 1 August and were seen regularly until 13 August. Three types of habitat used by geese during the brood-rearing period were distinguished: tidal marshes dominated by Carex subspathacea and Puccinellia phryganodes; wet moss-covered meadows with up to 5 cm of standing water, dominated by Carex stans, Dupontia fisheri, Calamagrostis neglecta, and Arctagrostis latifolia; and, around ponds, bands of vegetation 1-2 m wide dominated by Carex stans. The three most important species of monocots grazed by geese were Puccinellia phryganodes, Carex subspathacea, and C. stans. It is unlikely that habitat and food resources are limiting factors for Greater Snow Geese in the High Arctic during the brood-rearing period. We suggest that potential breeding areas for this species be identified and given special protection.Key words: Greater Snow Goose (Anser caerulescens atlanticus), habitat use, brood, Baffin Island, grazing, monocots, wet meadowsMots clés: Grande Oie Blanche (Anser caerulescens atlanticus), utilisation de l'habitat, élevage des jeunes, Terre de Baffin, alimentation, monocotylédones, zones humide

Design, synthèse et étude-structure activité des bactériocines synthétiques pour l'utilisation dans les secteurs alimentaire, vétérinaire et médical

La résistance aux antibiotiques est devenue un problème majeur dans la prévention et le traitement des infections bactériennes. Comme elles démontrent des activités inhibitrices in vitro contre un grand nombre de bactéries pathogènes cliniquement importantes, les bactériocines sont de plus en plus considérées comme une alternative potentielle aux antibiotiques conventionnels. Malgré cet énorme potentiel, leur utilisation est grandement limitée par les coûts élevés associés à leur production par fermentation. La synthèse chimique de ces dernières a été envisagée, mais aucune approche n’a donné jusqu’à maintenant un rendement qui puisse faire diminuer significativement les coûts de production. Dans le but de développer une voie de synthèse efficace pour ces peptides antibactériens, nous avons utilisé comme modèle la pédiocine PA-1, une bactériocine de classe IIa avec une activité anti-Listeria. L’optimisation de l’approche synthétique nous a permis d’augmenter les rendements de 1% à 45% et de concevoir des analogues avec des propriétés pharmacologiques améliorées comme une plus grande résistance à l’oxydation et à la lyse enzymatique. Cette importante réalisation nous a non seulement permis de produire la bactériocine en grande quantité, mais aussi déterminer sa structure tridimensionnelle et d’évaluer son impact sur le microbiote au niveau du tractus gastro-intestinal humain. L’approche développée s’est également avérée efficace pour la production d’autres bactériocines de la classe II comme la bactofencine A et permet de cibler davantage de pathogènes qu’on retrouve dans les différents secteurs alimentaire, vétérinaire et médical. En plus de décrire la synthèse et les études structure-activité de la bactofencine A, cet ouvrage présente les stratégies utilisées pour produire et déterminer la structure de la pédiocine PA-1 ainsi que les études sur son activité antimicrobienne et ses effets sur le microbiote dans le tractus gastro-intestinal.Antibiotic resistance has become a major problem in the prevention and treatment of bacterial infections. As they demonstrate in vitro inhibitory activities against a large number of clinically important pathogenic bacteria, bacteriocins are increasingly seen as a potential alternative to conventional antibiotics. Despite this enormous potential, their use is greatly limited by the high costs associated with their production by fermentation. The chemical synthesis of the latter has been considered, but no approach has yielded so far a yield that can significantly reduce production costs. In order to develop an efficient synthetic route for these antibacterial peptides, we used as model the pediocin PA-1, a class IIa bacteriocin with anti-Listeria activity. Optimization of the synthetic approach allowed us to increase yields by 1% to 45% and to design analogues with improved pharmacological properties such as greater resistance to oxidation and enzymatic lysis. This important achievement allowed us to not only produce bacteriocin in large quantities but also to determine its three-dimensional structure and to evaluate its impact on the microbiota in the human gastrointestinal tract. The approach developed has also been shown to be effective for the production of other class II bacteriocins such as Bactofencin A and allows targeting more pathogens found in the different food, veterinary and medical sectors. In addition to describing the synthesis and structure-activity studies of Bactofencin A, this book presents the strategies used to produce and determine the structure of pediocin PA-1 as well as studies on its antimicrobial activity and its effects on microbiota. the gastrointestinal tract

Design, synthèse et étude structure-activité d’analogues synthétiques du peptide antimicrobien Microcine J25

L’augmentation et la propagation alarmante de la résistance aux antibiotiques chez les bactéries pathogènes sont devenues un problème important de santé publique. Pour surmonter cette situation inquiétante, il y a un besoin croissant de nouveaux agents antimicrobiens avec des modes d’action innovants. La grande majorité des espèces bactériennes utilisent des peptides pour se défendre et se protéger contre d’autres microorganismes dans leur environnement. Ces peptides antimicrobiens possèdent des spectres d’activité et modes d’action très variés et représentent une source très intéressante pour découvrir et développer des agents antibactériens efficaces. L’objectif du projet consistait à faire le design et la synthèse d’analogues du peptide antimicrobien microcine J25 pour effectuer des études structure-activité et mieux comprendre les modes d’action. Comme la microcine J25 possède une structure particulière en lasso et extrêmement difficile à reproduire de façon synthétique, la stratégie était de faire le design par approche computationnelle d’analogues capables de mimer la structure de la microcine J25 sans passer par le lasso. Après leur synthèse, ces analogues ont été utilisés dans une étude structure-activité pour mieux comprendre l’impact de la structure sur le mode d’action et identifier les parties de la microcine J25 qui sont impliquées dans le transport et les interactions avec les cibles bactériennes.The increasing and alarming spread of antibiotic resistance by pathogenic bacteria have become an important public health problem. To overcome this worrying situation, there is a growing need for new antimicrobial agents with innovative modes of action. The vast majority of bacterial species use peptides to defend and protect themselves against other microorganisms in their environment. These antimicrobial peptides possess a wide range of activity spectra and modes of action and are a very good source to discover and develop effective antimicrobial agents. The objective of this project was to design and synthesize analogues of the antimicrobial peptide microcin J25 to perform structure-activity studies for a better understanding of its modes of action. As the microcin J25 has a particular lasso structure that is extremely difficult to replicate synthetically, the strategy was to design by computational approach analogues capable of mimicking the microcin J25’s structure without the lasso topology. After synthesis, these analogs were used in a structure-activity study to better understand the impact of the structure on the mode of action and identify parts of the microcin J25 that are involved in the transport and interactions with bacterial targets

The Synthesis of Architecture and Decor

This chapter discusses the influences on Charles Percier\u27s style and the ways in which there were continuities between his design aesthetics during the post-French Revolution period and earlier architects. Furthermore, with the accession of Napoleon Bonaparte, Percier fully deployed his ornamental strategy to give legitimacy to the upstart imperial court

Cities of Artificial Excavation: The Work of Peter Eisenman, 1978-1988 Introduction

In this introduction, Bédard traces American architect Peter Eisenman\u27s evolution as an architect and theorist from his work on houses from 1967 until 1980 to a body of work titled, Cities of Artificial Excavation, which he completed between 1978 and 1988. In Cities of Artificial Excavation, Eisenman interrogates a series of fictions by using dissimulation to produce an artificial architecture

Prints by Gabriel Huquier after Oppenord\u27s Decorated Ripa

This article discusses the ways in which Gabriel Huquier altered the designs of other artists and printmakers to create new prints. In particular, Bédard examines Huquier\u27s reproduction of a copy of Cesare Ripa\u27s Iconologia. Huquier did not appropriate Oppenord\u27s Ripa in its entirety or follow the original sequence of drawings. Instead he produced a series of prints that feature elements randomly chosen from it. Bédard argues that Oppenord and Huquier were both bricoleurs, but who had different objectives for their projects. While Oppenord attempted to interpret the text, Huquier was concerned with profit

REVIEW: Jules Hardouin-Mansart; Jules Hardouin-Mansart, 1646–1708; Bâtir pour le roi: Jules Hardouin-Mansart (1646–1708)

In this review, Jean-François Bédard examines two book projects that look at Jules Hardouin-Mansart, who became First Architect to the King in 1681 and Superintendent of Works in 1699. His tenure was marked by a great flurry of activity and the generation of an immense quantity of documents. However, Hardouin-Mansart\u27s professional and social success had a negative impact on the critical reception of his work. In fact many architectural historians doubted that he was behind many of the projects. The projects attempt to reevaluate Hardouin-Mansart\u27s legacy as a designer. Bertrand Jestaz\u27s two volume Jules Hardouin-Mansart is a greatly expanded and revised version of his groundbreaking but unpublished dissertation, supported by a wealth of documentary evidence. The second book, Jules Hardouin-Mansart, 1646-1708 by Alexandre Gady, takes the form of a lavishly illustrated multi-authored work that explores Hardouin-Mansart\u27s work from a variety of perspectives. The stimulating dialogue between the two publications establishes a fertile context for future studies of Hardouin-Mansart

REVIEW: Richard Whitman, Architecture, Print Culture, and the Public Sphere in Eighteenth-Century France

This review of Richard Whitman\u27s Architecture, Print Culture, and the Public Sphere in Eighteenth-Century France (Routledge, 2007) examines the relationship between architectural discourse and political power in Frame from 1671 until the end of the ancient regime. The volume successfully foregrounds the socio-political functions of architectural writing, though the use of Habermas\u27 thesis proves to be less convincing. Some of his arguments also tend to be simplistic or schematics .Nonetheless, this volume is a valuable contribution to the study of French architecture during the eighteenth century

Lessons from Bernard Rudofsky

A review of the exhibition of Bernard Rudofsky\u27s work, organized by the Architekturzentrum Wien and the Getty Research Institute (GRI) in associated with the Canadian Centre for Architecture (CAA). This exhibit outlined Rudofsky\u27s career and theoretical interests. Rudofsky was at the margins of high modernism, but unlike some of his contemporaries, focused on traditional, indigenous vernacular forms