Sökning: "invaders"

Visar resultat 1 - 5 av 17 avhandlingar innehållade ordet invaders.

1. 1. The threat from non indigenous species - ecosystem vulnerability, global distribution and co-occurrence with other major threats

   Författare :Helena Berglund; Biodiversitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; threats; distribution range; isolation; endemism; invasions; invaders; vulnerability; non indigenous species; rarity; threatened species;

   Sammanfattning : We live in a globalised world where people and goods travel large distances. Various species are brought along on these journeys, intentionally or as hitchhikers. Some of these species establish populations in regions to which they could not have spread without human assistance, and where they are considered to be non indigenous species (NIS). LÄS MER

3. 2. Effects of size-dependent predation and competition on population and community dynamics

   Författare :Karin Nilsson; Lennart Persson; Volker Rudolf; Umeå universitet; []
   Nyckelord :size-structure; cannibalism; resource competition; predation; emergent facilitation; population regulation; population dynamics; overcompensation; density-dependence; cycles; zooekologi; Animal Ecology;

   Sammanfattning : Most animals grow substantially during their lifetime and change in competitive ability, predatory capacity and their susceptibility to predation as they grow. This thesis addresses the implications of this on regulation and dynamics within populations as well as between population interactions. LÄS MER

4. 3. Alternative Stable States in Size-Structured Communities : Patterns, Processes, and Mechanisms

   Författare :Arne Schröder; Lennart Persson; André M. de Roos; Tim Benton; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; biomass overcompensation; Chaoborus; emergent Allee effect; Heterandria formosa; juvenile recruitment bottlenecks; ontogenetic niche shifts; Poecilia reticulata; Biology; Biologi;

   Sammanfattning : Alternative stable states have been, based on theoretical findings, predicted to be common in ecological systems. Empirical data from a number of laboratory and natural studies strongly suggest that alternative stable states also occur in real populations, communities and ecosystems. LÄS MER

5. 4. Physical and biological dispersal barriers in invasive, bloom-forming microalgae

   Författare :Ingrid Sassenhagen; Enhet akvatisk ekologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Dispersal barriers; microalgae; phenotypic differentiation; population genetics; priority effects;

   Sammanfattning : For a long time microorganisms were assumed to have unlimited dispersal due to their small size and high cell numbers. Most microbial species can be transported by water currents, in water droplets by wind and attached to other organisms. LÄS MER

7. 5. The type I-E CRISPR-Cas system : Biology and applications of an adaptive immune system in bacteria

   Författare :Lina Amlinger; Magnus Lundgren; Peter Fineran; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; CRISPR; CRISPR-Cas; virus defense; bacteria; bacteriophage; adaptation; spacer integration; interference; gene silencing; fluorescent reporter; Escherichia coli; Mikrobiologi; Microbiology;

   Sammanfattning : CRISPR-Cas systems are adaptive immune systems in bacteria and archaea, consisting of a clustered regularly interspaced short palindromic repeats (CRISPR) array and CRISPR associated (Cas) proteins. In this work, the type I-E CRISPR-Cas system of Escherichia coli was studied.CRISPR-Cas immunity is divided into three stages. LÄS MER