Characterising avian haemosporidian communities : ecological factors, parasite persistence and co-infection

Les parasites jouent un rôle clef dans l'évolution des comportements et des traits d'histoire de vie de leurs hôtes. Le parasitisme s'avère parfois dévastateur à l'échelle de population d'hôtes, et peut également altérer certains traits associés à la valeur sélective d'un individu infecté, tels que son succès reproducteur ou encore son taux de mortalité. La coévolution hôte/parasite, qui représente l'une des forces sélectives les plus puissantes dans l'évolution des organismes, peut également conduire les partenaires de l'association parasitaire à s'adapter localement à des environnements hétérogènes. Cette thèse porte sur l'étude de parasites aviaires, du genre Plasmodium, Haemopro- teus et Leucocytozoon (Haemosporidae), naturellement associés à différentes populations de mésanges charbonnières (Parus major) et d'hirondelles des fenêtres (Delichon ur- bicum). Dans un premier temps, nous avons cherché à déterminer comment se distribuent ces parasites au sein de différentes populations hôtes et si ces communautés de parasites sont structurées. Par la suite, la principale question à laquelle nous voulions répondre était de savoir comment ces parasites, et notamment après coexistence de plusieurs lignées génétiques d'Haemosporidae au sein dun même-individu (i.e. co-infection), affectent la physiologie et le succès de reproducteur des hôtes. Nos résultats suggèrent que la distribution des Haemosporidae est principalement gouvernée par la présence d'insectes vecteurs et que la persistance de l'infection chez les hôtes varie en fonction du genre d'Haemosporidae (Chapitre 1-2). Par ailleurs, nous avons trouvé que des lignées de parasite génétiquement distinctes peuvent avoir des effets contrastés sur leurs hôtes. Par exemple, les hôtes exhibent des différences de parasitémie marquées en fonction des lignées de parasites responsable de l'infection. De plus, le succès reproducteur ainsi que la charge parasitaire des mésanges infectées par Plasmodium ou Haemoproteus n'étaient pas affecté par l'infection simultanée avec Leucocytozoon (Chapitre 2-3). Dans le Chapitre 4, j'ai examiné la capacité immunitaire de mésanges charbonnières infectées par des hémosporidies. Les résultats n'ont pas été concluant, et je suggère fortement une réévaluation de ceux-ci dans de futures études. Les mésanges charbonnières ne semblent pas signaler leur statut infectieux par la coloration de leur plumage (Chapitre 5); toutefois, la coloration noire des plumes reflète l'état de stress oxydatif des mésanges, qui dépend lui-même de l'infection parasitaire. La coloration verte pourrait également indiquer la qualité des soins paxentaux délivrés par les mésanges adultes femelles à leurs petits, comme le suggère la corrélation que nous avons observée entre la masse des jeunes d'une nichée et la coloration de leur mère. Les hirondelles capturées en Algérie souffrent plus de l'infection que celles échantillon¬nées en Europe (Chapitre 6). Les similitudes observées entre les communautés de par¬asites affectant les populations européennes et celles des populations nord-africaines suggèrent que la transmission des parasites a lieu lors de la migration vers le sud. A l'instar de nos observations sur les mésanges dans les chapitres 2 et 3, les hirondelles co-infectées ne montrent pas d'altérations de leur condition physique. Cette thèse démontre qu'il existe, au sein des populations de mésanges charbonnières, des interactions antagonistes entre, d'une part, les parasites et leurs hôtes et d'autre part, entre différent parasites. Le résultat de ces interactions antagonistes varie en fonction des espèces et de la zone géographique considérée. Nous avons démontré que les interactions ne suivent pas toujours la théorie, puisque la coevolution qui, en suivant le concept de la virulence, devrait augmenter la charge parasitaire et diminuer la condition physique des hôtes, ne montre pourtant pas d'impact négatif sur les populations de mésanges. Nous pouvons maintenant concentrer nos efforts à la caractérisation des interactions antagonistes. De plus, grâce aux avancées des méthodes moléculaires, nous pouvons suivre et étudier en détails comment ces interactions se manifestent et quels sont leurs effets sur la condition physique des hôtes. - Parasites are key in shaping various behavioural and life-history traits of their hosts. The influence of parasitism on host populations varies from slight to devastating and might influence such parameters as mortality rates or reproductive success. Host-parasite coevolution is one of the most powerful selective forces in evolution and can lead to local adaptation of parasites and hosts in spatially structured environments. In this thesis, I studied haemosporidian parasites in different populations of great tits (Parus major) and house martins (Delichon urbicum). Firstly, I wanted to determine how parasites are distributed and if parasite communities are structured. The main question I wanted to address hereafter was how parasites, and specifically infection with multiple genera of parasites (i.e. co-infection) influenced host physiology and reproductive success. I found that parasite distribution is environmentally driven and could therefore be closely linked to vector prevalence; and that the stability of parasite infection over time is genus-dependent (Chapter 1 - 2). I further found that different haemosporidian lineages might interact differently with their hosts as parasitaemia was strongly lineage-specific and that the presence of Leucocytozoon parasites showed no correlation to Plasmodium or Haemoproteus parasitaemia, nor to great tit reproductive success (Chapter 2-3). In Chapter 4 I examined immune capacity of haemosporidian-infected great tits. The results proved inconclusive, and I strongly suggest re-evaluation hereof in future work. Great tits do not appear to signal parasite infection through plumage colouration (Chapter 5); however, infection did have a link to oxidative stress resistance which is strongly signalled through the black breast stripe, with darker males being more resistant and darker females less resistant. Females might incur different costs associated with darker stripes. This would allow reversal of signaling function. Green colouration could also serve as a cue for female provisioning quality as indicated by the strong correlation between colouration and chick body mass. Breeding house martins caught in Algeria suffer greater haemosporidian infection than European populations (Chapter 6). Similar parasite communities in European and North-African populations suggest transmission of parasites may occur during southward migration. Similarly to what was observed in great tits in Chapter 2 and 3, no relationship was found between parasite co-infection and Swiss house martin body condition. This thesis demonstrates that host-parasite and inter-parasite antagonistic interac¬tions exist in great tit populations. How these interactions play out is species dependent and varies geographically. I have demonstrated that interactions do not always follow the theory, as co-infection - which under the concept of virulence should increase parasitaemia and decrease body condition - showed no negative impact on great tit populations. We can now concentrate our efforts on characterising these antagonistic interactions, and with the advance in molecular methods, track and investigate how these interactions play out and what the effect on host fitness is.

IL-17F co-expression improves cell growth characteristics and enhances recombinant protein production during CHO cell line engineering.

The generation of a high productivity cell line is a critical step in the production of a therapeutic protein. Many innovative engineering strategies have been devised in order to maximize the expression rate of production cells for increased process efficiency. Less effort has focused on improvements to the cell line generation process, which is typically long and laborious when using mammalian cells. Based on unexpected findings when generating stable CHO cell lines expressing human IL-17F, we studied the benefit of expressing this protein during the establishment of production cell lines. We demonstrate that IL-17F expression enhances the rate of selection and overall number of selected cell lines as well as their transgene expression levels. We also show that this benefit is observed with different parental CHO cell lines and selection systems. Furthermore, IL-17F expression improves the efficiency of cell line subcloning processes. IL-17F can therefore be exploited in a standard manufacturing process to obtain higher productivity clones in a reduced time frame.

The effect of innovation and sex-specific migration on neutral cultural differentiation

Studies of behaviour are increasingly focusing on acquisition of traits through cultural inheritance. Comparison of patterns of spatial population structure (FST) between neutral genetic loci and behavioural or cultural traits can been used to test hypotheses about demography, life history, and the mechanisms of inheritance/transmission of these traits in humans, chimpanzees and other animals. Here, we develop analytical expectations to show how FST in cultural traits can differ strongly from that measured at neutral genetic markers if migration is largely restricted to one sex but social learning is predominantly modelled on the other (e.g. males migrate, females serve as models for cultural traits), if one individual is the learning model for many, or if rates of innovation (individual learning) are high or rates of social learning are low. We discuss how comparisons of FST between genetic loci and behavioural traits can be applied to evaluate the importance of innovation in shaping patterns of cultural differentiation, as even low rates of innovation can considerably reduce FST, relative to observed structure at neutral genetic loci. Our results also suggest that differentiation in neutral cultural traits should occur over much smaller scales in species with male migration and female enculturation (or the reverse).

Origins, evolution, and phenotypic impact of new genes.

Ever since the pre-molecular era, the birth of new genes with novel functions has been considered to be a major contributor to adaptive evolutionary innovation. Here, I review the origin and evolution of new genes and their functions in eukaryotes, an area of research that has made rapid progress in the past decade thanks to the genomics revolution. Indeed, recent work has provided initial whole-genome views of the different types of new genes for a large number of different organisms. The array of mechanisms underlying the origin of new genes is compelling, extending way beyond the traditionally well-studied source of gene duplication. Thus, it was shown that novel genes also regularly arose from messenger RNAs of ancestral genes, protein-coding genes metamorphosed into new RNA genes, genomic parasites were co-opted as new genes, and that both protein and RNA genes were composed from scratch (i.e., from previously nonfunctional sequences). These mechanisms then also contributed to the formation of numerous novel chimeric gene structures. Detailed functional investigations uncovered different evolutionary pathways that led to the emergence of novel functions from these newly minted sequences and, with respect to animals, attributed a potentially important role to one specific tissue--the testis--in the process of gene birth. Remarkably, these studies also demonstrated that novel genes of the various types significantly impacted the evolution of cellular, physiological, morphological, behavioral, and reproductive phenotypic traits. Consequently, it is now firmly established that new genes have indeed been major contributors to the origin of adaptive evolutionary novelties.

Regulierungen an der Schnittstelle zwischen den Ressourcen Wald und Klima : Einflussfaktoren auf die Inwertsetzung der CO₂-Senkenleistung des Waldes

Les forêts dont le volume sur pied augmente contribuent à atténuer les changements climatiques et constituent un puits de carbone. En Suisse, seul très peu d'entreprises forestières valorisent le service de puits de carbone. Ce travail vise à chercher les raisons expliquant cette réticence. Les facteurs politiques et juridiques influençant les décisions des entreprises forestières sont analysées à l'aide du modèle des régimes institutionnels de ressource. Les résultats obtenus sont vérifiés et complétés à l'aide d'informations collectées lors d'interviews d'experts menées auprès d'entreprises forestières et décideurs politiques. Cette étude identifie des facteurs favorisant ou entravant la valorisation du service de puits de carbone des forêts et propose des options d'action.

Audit report on the Iowa Innovation Corporation for the period from October 24, 2011 (the date of inception) through June 30, 2012

Audit report on the Iowa Innovation Corporation for the period from October 24, 2011 (the date of inception) through June 30, 2012

Redes informais nas organizações: a co-gestão do conhecimento

As redes informais nas organizações constituem estruturas auto-organizantes que, respondendo em grande parte pela capacidade de as organizações lidarem com os problemas imprevistos, configuram-se como instrumentos importantes ao enfrentamento dos desafios associados à sociedade da informação. Este trabalho aborda as redes informais sob a perspectiva do processamento humano da informação e do conhecimento que efetuam e dos suportes eletrônicos de comunicação que ampliam sua utilização dentro das organizações.

Open access and connectedness: stimulating unexpected innovation through the use of institutional open archives

The author reviews past work with Ibict and the global progress made by the Open Access Movement. He postulates a theory of open access being an example of a complex adaptive system created by Internet-based scholarly publishing. Open access could be the cause of a cascade of increasing complexity and opportunities that will reshape this system. He has chosen the pervasive and global "Connectedness" created by the internet and the content spaces it provides for open access collections as a "simple disruptive agent". He discusses how connectedness influences infinite variety, creativity, work, change, knowledge, and the information economy. Case studies from the University of New Mexico Libraries are used where appropriate.

Photosynthesis and Rubisco kinetics in spring wheat and meadow fescue under conditions of simulated climate change with elevated CO[sub 2] and increased temperatures

Selostus: Kevätvehnän ja nurminadan fotosynteesi ja Rubisco-kinetiikka simuloidun ilmastonmuutoksen eli kohotetun hiilidioksidipitoisuuden ja kohotetun lämpötilan oloissa

Firm's network capability and innovation performance: evidences from China hi-tech industry

ABSTRACT : A firm's competitive advantage can arise from internal resources as well as from an interfirm network. -This dissertation investigates the competitive advantage of a firm involved in an innovation network by integrating strategic management theory and social network theory. It develops theory and provides empirical evidence that illustrates how a networked firm enables the network value and appropriates this value in an optimal way according to its strategic purpose. The four inter-related essays in this dissertation provide a framework that sheds light on the extraction of value from an innovation network by managing and designing the network in a proactive manner. The first essay reviews research in social network theory and knowledge transfer management, and identifies the crucial factors of innovation network configuration for a firm's learning performance or innovation output. The findings suggest that network structure, network relationship, and network position all impact on a firm's performance. Although the previous literature indicates that there are disagreements about the impact of dense or spare structure, as well as strong or weak ties, case evidence from Chinese software companies reveals that dense and strong connections with partners are positively associated with firms' performance. The second essay is a theoretical essay that illustrates the limitations of social network theory for explaining the source of network value and offers a new theoretical model that applies resource-based view to network environments. It suggests that network configurations, such as network structure, network relationship and network position, can be considered important network resources. In addition, this essay introduces the concept of network capability, and suggests that four types of network capabilities play an important role in unlocking the potential value of network resources and determining the distribution of network rents between partners. This essay also highlights the contingent effects of network capability on a firm's innovation output, and explains how the different impacts of network capability depend on a firm's strategic choices. This new theoretical model has been pre-tested with a case study of China software industry, which enhances the internal validity of this theory. The third essay addresses the questions of what impact network capability has on firm innovation performance and what are the antecedent factors of network capability. This essay employs a structural equation modelling methodology that uses a sample of 211 Chinese Hi-tech firms. It develops a measurement of network capability and reveals that networked firms deal with cooperation between, and coordination with partners on different levels according to their levels of network capability. The empirical results also suggests that IT maturity, the openness of culture, management system involved, and experience with network activities are antecedents of network capabilities. Furthermore, the two-group analysis of the role of international partner(s) shows that when there is a culture and norm gap between foreign partners, a firm must mobilize more resources and effort to improve its performance with respect to its innovation network. The fourth essay addresses the way in which network capabilities influence firm innovation performance. By using hierarchical multiple regression with data from Chinese Hi-tech firms, the findings suggest that there is a significant partial mediating effect of knowledge transfer on the relationships between network capabilities and innovation performance. The findings also reveal that the impacts of network capabilities divert with the environment and strategic decision the firm has made: exploration or exploitation. Network constructing capability provides a greater positive impact on and yields more contributions to innovation performance than does network operating capability in an exploration network. Network operating capability is more important than network constructing capability for innovative firms in an exploitation network. Therefore, these findings highlight that the firm can shape the innovation network proactively for better benefits, but when it does so, it should adjust its focus and change its efforts in accordance with its innovation purposes or strategic orientation.

Nodulação e rendimento de soja co-infectada com Bacillus Subtilis e Bradyrhizobium Japonicum / Bradyrhizobium Elkanii

O Bacillus subtilis pode favorecer o desempenho simbiótico do rizóbio, pelos efeitos na inibição de fitopatógenos ou pela exsudação de fitormônios. Com o objetivo de verificar a viabilidade da co-infecção de sementes de soja com Bradyrhizobium e Bacillus foram conduzidos três experimentos, no Paraná, em solos com população estabelecida de Bradyrhizobium, em que as estirpes de Bradyrhizobium SEMIA 5019 e SEMIA 5080 e suas variantes tolerantes aos metabólitos de Bacillus foram co-infectadas com duas estirpes de Bacillus (AP-3 e PRBS-1), ou seus metabólitos. Na safra 1993/94, em Londrina, o tratamento de co-inoculação de Bradyrhizobium com os metabólitos formulados de Bacillus incrementou, significativamente, em relação ao não-inoculado, o número de nódulos (59%, estádio V3), a ocupação dos nódulos pelas estirpes de Bradyrhizobium (76%, R2) e o rendimento de grãos (24%); em Ponta Grossa, esses incrementos foram de 60%, 145% e 22%, respectivamente. Nessa safra, em Londrina, a co-inoculação das variantes tolerantes com os metabólitos de Bacillus também aumentou o rendimento (26%) e N total (17%) dos grãos de soja e incrementos significativos foram constatados, na ocupação dos nódulos, pela co-inoculação das variantes tolerantes com as células de Bacillus (78%). Os resultados obtidos indicam a viabilidade da co-inoculação, em sementes de soja, de metabólitos brutos ou formulados ou, ainda, de células de Bacillus subtilis, para incrementar a contribuição do processo de fixação biológica do nitrogênio.

La politique régionale : entre compétitivité et respect de l'environnement

Aujourd'hui plus que jamais, le développement économique ne peut se faire au détriment de notre environnement naturel. Dès lors se pose la question de savoir comment parvenir à maintenir la compétitivité d'une économie, tout en tenant compte de l'impact qu'elle a sur révolution du cadre naturel. La présente recherche propose d'investiguer sur la question en se penchant sur les politiques publiques de promotion économique, et plus spécifiquement sur la politique régionale. Faut-il maintenir la confiance dans les courants néoclassiques, comme le laisse supposer la situation actuelle, renforcer la position d'une économie s'inscrivant au sein d'un cadre socio-environnemental ou encore repenser notre mode de fonctionnement économique quant à son développement ? Dans le cas présent, la politique régionale suisse est évaluée à la lumière de trois stratégies de développement économique. D'une part, il y a l'économie fondée sur la connaissance. Cette dernière est à la base de la philosophie actuelle en matière de politique régionale. Ensuite, il y a l'écologie industrielle, qui pour sa part fait la promesse d'un développement économique éco-compatible. Enfin, la troisième stratégie est celle de l'économie de fonctionnalité, qui propose de maximiser l'efficience d'une unité de matière première en limitant notamment la notion de propriété. Au travers d'une grille d'analyse construite sur le modèle des géographies de la grandeur, les trois stratégies sont confrontées aux objectifs de la nouvelle politique régionale suisse (NPR) ainsi qu'à ses modalités de mise en oeuvre. Il en ressort qu'en l'état actuel, la stratégie misant sur l'économie de la connaissance est la plus à même de relever le défi d'un développement économique durable. Toutefois, moyennant adaptations, les autres stratégies pourraient également se révéler être pertinentes. On constate notamment que les éléments clés sont ici l'innovation, ainsi que les dimensions spatiale et temporelle des stratégies. Nous recommandons dès lors d'adopter une approche territorialisée du développement économique, selon une logique de projet au sens de Boltanski & Chiapello. A notre sens, seules les propositions à même de fédérer les acteurs et disposant d'une vision intégrée du développement ont une chance de permettre un développement économique en harmonie avec notre cadre environnemental. - Today more than ever, economic development can't go ahead without consideration for our natural environment. This lays us with the question of how to maintain the competitiveness of an economy, and at the same time to manage the impact of it on the natural frame. This research aims to investigate this question through public policies fostering economy, more specifically through the regional policy. Must one trust the neo-classical way, as the actual situation let's think about it, reinforce the position of an economy within a socio- environmental frame or moreover reinvent our economical modus regarding development? In this case, an assessment of the Swiss regional policy is lead through three strategies of economic development. First, there is the knowledge economy. It is the core concept of the actual philosophy regarding regional policy. Second, there is the industrial ecology which aims to promote an eco-compatible economic development. Last, there is the functional economy, which proposes to maximize the efficiency of every used unit of natural resources by limiting in particular the notion of propriety. Through an analytic frame built on the model of geographies of greatness (géographies de la grandeuή, the three strategies are confronted to the objectives of the Swiss new regional policy (NRP) as well as its implementation. It turns out that actually, the strategy laying on the knowledge economy happens to be the best solution in order to promote a sustainable economic development. Nevertheless, with few adaptations, the other strategies could be pregnant as well. What we can see is that key- elements are here the innovation, as well as the spatial and temporal dimensions of these strategies. We recommend therefore to adopt a territorialised approach of economic development, with a project-based logic as meant by Boltanski & Chiapello. We are convinced that only propositions which are able to unit actors, and with an integrated point of view, have a chance to promote economic development in harmony with our environmental frame.