No description available.

Aquatic plants play an important role in the survival and proliferation of invertebrates in freshwater ecosystems. Exotic plants are now common in North American lakes and rivers, where they may displace native plants, thereby potentially altering epiphytic invertebrate communities. Differences in aquatic invertebrate communities on native and exotic plants are examined here through (1) a meta-analysis of published data, and (2) two field surveys in northeastern North America that compared invertebrates on the exotic Myriophyllum spicatum and Potamogeton crispus to those on their native congeners. The meta-analysis revealed that exotic plants generally support lower invertebrate abundance than do natives, while invertebrate taxa richness tends to be similar on exotic and native plants. The field surveys demonstrated that M. spicatum and P. crispus support significantly different invertebrate densities and lower taxa richness than their structurally similar native congeners. These results suggest that the replacement of native plants by exotics---even those with similar morphology---may cause concomitant changes to aquatic ecosystems.

Russian Federation has reconsidered its foreign policy on the European Union and is now focusing more on Eurasian integration. This step aroused various reactions in the world, especially after the creation of the Eurasian Economic Union in January 2015. This work deals with the intention of the Union, examines the steps which preceded this event and the possible influence of the eurasianism on Eurasian integration. At the same time, based on the statements of both parties -- European and Eurasian -- the work analyzes potential point of possible cooperation between the European Union and the newly formed regional integration Eurasian Economic Union.

This thesis examines the space use, movement and contact rate patterns of a high- density, group-living, Eurasian badger (Meles meles) population in the UK naturally infected with bovine tuberculosis (bTB). Recently developed proximity logging devices were deployed on a representative sample of 51 badgers from eight different social groups to track their movements using radio-telemetry and to quantify their within- and between-group contact rates. Whilst interactions within social groups accounted for more than 90% of contacts, the entire study population was ultimately connected through interactions among individuals from neighbouring groups. Both within and between-group contacts, and also the use of denning sites, were heavily influenced by seasonal and demographic factors, which appear to be motivated to a large extent by reproductive behaviours. Nevertheless, by using social network analysis I found that badgers that tested positive for bTB were found to interact with fewer of their group members and for a shorter amount of time. Specifically these test-positive individuals were found to associate with test-negative group members significantly less than would be expected by chance. Those animals testing positive for bTB were also found to use outlying setts significantly more frequently than those that tested negative. The within and between-group contact rates of individuals were found to correlate with their sett use patterns. Those animals that spent less time interacting with group members and those that spent more time interacting with members of foreign social groups, were found to spend a greater proportion of their time at outlier setts. The findings in this thesis suggest a link between wider roaming behaviour and the disease status of an individual. This adds support to the argument that the social disruption of badger populations, for example through culling, may promote rather than alleviate the spread of bTB as a result of increased movement and contacts between groups. State-of-the-art technology has enabled me to demonstrate the strong influence that badger social organisation may have on the transmission of an economically significant infectious disease. My findings suggest that disease control measures might be enhanced by taking into account seasonal and individual-level variation in ranging behaviour and use of outlier setts, for example, by identifying and targeting functional groups of individuals, specific areas, or times of the year that contribute disproportionately to disease spread.

The physiological responses of Myriophyllum spicatum to 2,4-D, diquat and copper were quantified using a plant tissue viability assay, and daily measures of dissolved oxygen and pH. Correlations of herbicide tissue residues to physiological response measures were determined and the relationship was used to develop exposure-response models. Diquat and copper had a greater effect on plant tissue viability than was observed for 2,4-D. Diquat produced greater reductions in dissolved oxygen concentrations and pH values than 2,4-D or copper. Copper exposure had the least effect on these parameters. Exposure-response models developed for 2,4-D predicted effective control at plant tissue residues ranging from 4000 to 4700 mg/kg. Aqueous exposure concentrations necessary to produce effective control plant tissue residues ranged from 0.20 to 0.40 mg/L. Exposure-response models developed for diquat predicted effective control at plant tissue residues ranging from 225 to 280 mg/kg. Aqueous exposure concentrations necessary to produce effective control plant tissue residues ranged from 0.113 to 0.169 mg/L. Exposure-response models developed for copper predicted effective control at plant tissue residues ranging from 680 to 790 mg/kg. Aqueous exposure concentrations necessary to produce effective control plant tissue residues ranged from 0.32 to 0.64 mg/L. Model predictions for 2,4-D, diquat and copper were within 0.5 mg/L of the manufacturers' label recommendations for these herbicides. The use of laboratory microcosms in development of exposure-response models for diquat and copper produced results comparable to those using the larger-scale greenhouse systems. Diquat effectively controlled M. spicatum at lower tissue residues than 2,4-D or copper. In addition, initial aqueous exposure concentrations were also lower for diquat. Use of these models in field situations should be coupled with considerations of quantity of biomass present and environmental conditions, such as turbidity, in order to accurately calculate exposure concentrations necessary for effective tissue residues. Thus, the use of these models can be used to optimize the impact on the target species while minimizing exposure for nontarget species.

Jordens biologiska mångfald minskar i en allt snabbare takt, men mitt i denna ekologiska katastrof börjar arter på vissa håll att återkomma. De stora rovdjuren i Europa är ett sådant exempel. Från att ha varit försvunna från stora delar av sina utbredningsområden är de flesta populationer numera stabila eller ökande. I Skandinavien har lodjurspopulationen expanderat och efter närmare 100 års reproduktiv frånvaro förekommer åter föryngringar i Sydsverige. I Östergötland finns i dagsläget ca 50–55 individer och mycket tyder på att stammen kommer att fortsätta öka. Genom att sammanställa och analysera data från inventeringsrapporter, observationsloggar och avskjutningsstatistik har jag undersökt lodjurspopulationens utveckling i Östergötland och beräknat länets bärkraft för lo. Beräkningen av bärkraften har utgått från klövviltförekomsten samt mängden lämpligt habitat. Resultaten visar att Östergötland har gott om lämpligt habitat och en hög bytesdensitet, som är jämförbar med flera lodjurstäta områden i Europa. Givet dessa förutsättningar har Östergötland en bärkraft för lo som ligger långt över dagens populationsnivå. Uppskattningsvis kan Östergötland hålla mellan 80–140 självständiga individer. Detta skulle innebära en fördubbling av dagens antal och kunna leda till såväl positiva som negativa konsekvenser för samhället. Lodjur kan innebära ett hot mot tamboskap, men de senaste årens rapportering visar att angreppen orsakade av lodjur är begränsade. Även påverkan på klövviltstammarna är i dagsläget försumbar. På sikt skulle dock en större lodjurspopulation kunna reglera klövviltet och på så vis minska mängden trafikolyckor och skador på skog. / Global biological diversity is declining at rates comparable to historic mass extinction events. Despite this, some species are returning to their former ranges, an example being the great carnivores in Europe. After being driven to the verge of extinction, most of today’s populations have recovered to a stable level. The Eurasian lynx (Lynx lynx) has re-expanded its range in Scandinavia and, after almost 100 years, is once again reproducing in southern Sweden. There are currently about 50-55 individuals in Östergötland county, and many factors implies that their number will continue to grow. By collecting and analysing data from different governmental reports and other sources I have tried to cover the development of Östergötland’s lynx population and to calculate the carrying capacity. The calculations are based on ungulate densities and amount of suitable habitat. The results of the study show that Östergötland contains a large amount of connected woodland habitat and high densities of prey, comparable to regions in Europe with high occurrence of lynx. Given these circumstances Östergötland has the capacity to support approximately 80-140 independent individuals. These numbers are twice as large as today’s population level and if reached could lead to positive as well as negative consequences for society. The lynx is a known threat to livestock but reports from recent years suggests that lynx attacks on sheep in Östergötland are limited. The effects of the current lynx population on ungulate demographics are also negligible. Although, these effects might increase with a larger lynx population, leading to lower rates of vehicle collisions and less damage in the forestry sector.

Magistro darbo tikslas - išsiaiškinti Eurazijos sąjungos idėjos realizavimo galimybes; tyrimo objektas - Eurazijos sąjungos idėja ir jos realizavimo galimybės; tyrimo problema – Eurazijos sąjungos idėjos įgyvendinimo realumas ir tolimesnės regioninės integracijos perspektyvos. Tyrime naudojami aprašymo ir analizės metodai, padedantys atskleisti analizuojamo objekto charakteristikas, raidą ir apsvarstyti tolimesnes realizavimo galimybes; lyginamoji analizė padeda išskirti įvairių šaltinių skirtumus ir panašumus. Analizei naudojami pirminiai ir antriniai šaltiniai. Magistro darbo struktūra atitinka darbo uždavinius ir tyrimas pradedamas nuo Eurazijos sąjungos idėjos pristatymo (daugiausia pirminių šaltinių analizė). Pristačius ir išanalizavus tyrimo objektą (Eurazijos sąjungos idėją) ir tokios idėjos vertinimus mokslininkų ir regioninių valstybių politikų pasisakymuose, susikoncentruojama į regioninės integracijos analizę, išskiriant tarpvyriausybinių derybų ir liberalaus tarpvyriausybiškumo teorijas, kaip tinkamiausias Eurazijos sąjungos idėjos įgyvendinimo analizei. Darbo įvade apsibrėžus, jog Eurazijos sąjungą kuriančios valstybės yra neoautoritarinės, trečiajame skyriuje išanalizuojama neoautoritarizmo samprata ir tokių valstybių funkcionavimo ypatumai. Siekiant kokybiškiau išanalizuoti Eurazijos sąjungos idėjos įgyvendinimo galimybes, susikoncentruojama ties regiono specifika, pristatomas Rusijos vaidmuo regione ir tarpvalstybinių santykių regione problemos bei... [toliau žr. visą tekstą] / The purpose of research – to find out the possibilities of Eurasian Union realization; the object of research – the idea of Eurasian Union and possibilities of its realization; the problem of research is the tangibility of Eurasian Union idea‘s realization and perspectives of further regional integration. The chosen analytical methods are descriptive research and analysis, which help to reveal characteristics and development of the research object and to consider possibilities of further realization; comparative analysis helps to distinguish differences and similarities of various sources. Primary and secondary sources are used in the analysis. Structure of this master thesis is based on the raised goals and research starts with presentation of the Eurasian Union idea (mostly the analysis of primary sources). After presenting the research object (Eurasian Union idea) and scholars and politicians opinions about the idea, research concentrates on the analysis of regional integration. Intergovernmentalism and liberal intergovernmentalism are determined as the most appropriate theories of analyzing realization of Eurasian Union idea. The third chapter of master thesis analyzes the concept of neoauthoritarianism and functioning of neoauthoritarian states. In order to improve quality of analyzing Eurasian Union idea’s realization possibilities, master thesis concentrates on the specific of the region; Russia’s role in the region; problems of the interstate relations in the... [to full text]

No description available.

Zugl.: Zürich, Univ., Diss., 2004/05

Aujourd’hui, la durabilité du modèle de développement de l’aquaculture est de plus en plus questionnée et une des solutions proposées consisterait à diversifier la production piscicole via la domestication de nouvelles espèces comme la perche commune, Perca fluviatilis, une espèce d’eau douce tempérée très intéressante pour la diversification de l’aquaculture continentale européenne. De nombreux aspects de la biologie de sa reproduction sont connus cependant, peu d’informations sont disponibles sur son développement. Or, des défauts de développement précoce, dont les causes sont encore mal définies, impactent actuellement la qualité de la production piscicole. C’est dans ce contexte que cette thèse vise à caractériser les succès et défauts de développement embryonnaire chez la perche commune à travers trois axes principaux : (i) déterminer une table de référence de l’embryogenèse normale permettant (ii) définir les défauts de développement tels que les malformations dans des conditions d’élevage différentes et (iii) identifier les liens entre différents paramètres de développement embryonnaire afin de déterminer des profils de développement variables. La première partie de ce travail a permis d’identifier la séquence précise de l’ontogenèse normale de cette espèce à travers la définition d’une table de développement embryonnaire alternative et flexible pour des espèces non-modèles, facilitant les comparaisons intra- et inter-espèces. Dans un second temps, l’identification la plus exhaustive possible de phénotypes anormaux a révélé 10 grandes catégories de malformations associées à des organes ou fonctions spécifiques. De plus, certains de ces défauts semblent fortement dépendants des conditions d’élevage des géniteurs ce qui permet d’identifier l’effet de potentiels facteurs extrinsèques sur le développement et d’améliorer les techniques de gestion des animaux. Enfin, l’ensemble de ces résultats et des paramètres mesurés durant l’embryogenèse ont permis d’effectuer une classification approfondie des pontes obtenues présentant des profils de développement similaires pour mettre en évidence des liens éventuels entre les divers phénotypes et paramètres utilisés. Les analyses de données effectuées ont montré que seulement 3 paramètres étaient nécessaires à la caractérisation de 4 profils de succès de développement variables : les taux de survie au début de l’organogenèse, d’éclosion et de malformations. A l’avenir, ces paramètres pourraient être généralisés permettant d’homogénéiser les critères d’évaluation du succès de développement chez d’autres espèces d’intérêt de poisson. L’ensemble de ces résultats constituent une base solide pour étudier l’effet des facteurs extrinsèques et/ou intrinsèques sur la qualité et le succès de développement embryonnaire / Currently, the durability of the aquaculture developmental model is clearly challenged and one solution consists to diversify the fish production by the domestication of new species such as the Eurasian perch (P. fluviatilis), a freshwater species promising and valuable for the diversification of European aquaculture. Several aspects of its reproductive biology are well known, nevertheless, only little information is available on its development. However, early developmental impairments, whose causes are unclear, actually impact the fish production quality. In this context, the present work aimed to characterize the developmental success and impairments in Eurasian perch on three main issues: (i) determine a model of normal embryogenesis table helping to (ii) define developmental impairments, in diverse rearing conditions and (iii) identify the relationships between various parameters of embryonic ontogenesis to characterize different patterns of developmental success. The first part of this study allowed identifying the accurate timing of normal ontogenesis of this species through the definition of an alternative and flexible developmental table to describe non-model fish species, allowing the intra- and inter-specific comparisons. In the second part, the exhaustive characterization of abnormal phenotypes revealed 10 categories of deformities linked to specific organs or functions. Moreover, some of these categories seemed to be related to rearing-conditions of the breeders allowing identifying the potential effects of extrinsic factors on the development and improving the management of fish. Finally, the previous results and the parameters measured during embryogenesis help to classify the several spawns obtained with the same developmental pattern and to highlight the potential relationships between diverse phenotypes and parameters. In addition, the data analyses showed that only 3 parameters are reliable to assess the developmental success: survival rate at the onset of the organogenesis, hatching and deformities rates. Henceforth, these parameters and this classification could be generalized as a new strategy to assess the developmental success in other fish species. All of these results provide a good basic knowledge to study the potential effects of various extrinsic and/or intrinsic factors on the developmental success and the embryonic quality