Sökning: "Experimental evolution"

Visar resultat 21 - 25 av 448 avhandlingar innehållade orden Experimental evolution.

1. 21. Constraints on up-regulation of drug efflux in the evolution of ciprofloxacin resistance

   Författare :Lisa Praski Alzrigat; Diarmaid Hughes; Fernando Baquero; Uppsala universitet; []
   Nyckelord :ciprofloxacin; antibiotic resistance; drug efflux; bacterial fitness; marR; acrR; marA; experimental evolution; Mikrobiologi; Microbiology;

   Sammanfattning : The crucial role of antibiotics in modern medicine, in curing infections and enabling advanced medical procedures, is being threatened by the increasing frequency of resistant bacteria. Better understanding of the forces selecting resistance mutations could help develop strategies to optimize the use of antibiotics and slow the spread of resistance. LÄS MER

3. 22. Evolutionary consequences of sex-specific selection

   Författare :Josefine Stångberg; Elisabeth Bolund; Elina Immonen; Jennifer Perry; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Caenorhabditis remanei; Callosobruchus maculatus; sex-specific selection; sexual selection; experimental evolution; intralocus sexual conflict; life history evolution; sexual dimorphism; trade-offs; Quantitative genetics;

   Sammanfattning : Sex-specific selection is widespread, evident by the evolution of sexual dimorphism in many traits in sexually reproducing taxa. The reason why the sexes may experience selection that differs in direction or magnitude is often linked to the reproductive strategies associated with the sex-specific reproductive physiology. LÄS MER

4. 23. A Unified Multitude : Experimental Studies of Bacterial Chromosome Organization

   Författare :Eva Garmendia; Diarmaid Hughes; Linus Sandegren; John R. Roth; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; bacterial evolution; chromosome organization and structure; chromosomal inversions; EF-Tu; horizontal gene transfer; Biologi med inriktning mot mikrobiologi; Biology with specialization in Microbiology;

   Sammanfattning : Bacteria are many, old and varied; different bacterial species have been evolving for millions of years and show many disparate life-styles and types of metabolism. Nevertheless, some of the characteristics regarding how bacteria organize their chromosomes are relatively conserved, suggesting that they might be both ancient and important, and that selective pressures inhibit their modification. LÄS MER

5. 24. The evolution of TOFu : Developing and utilizing neutron time-of-flight spectrometry of deuterium and tritium fusion plasmas at JET

   Författare :Benjamin Eriksson; Göran Ericsson; Anders Hjalmarsson; Sean Conroy; Jacob Eriksson; Luka Snoj; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fusion; plasma diagnostics; neutron spectrometry; time-of-flight; TOFOR; JET; Fysik med inriktning mot tillämpad kärnfysik; Physics with specialization in Applied Nuclear Physics;

   Sammanfattning : Considerable effort has been invested in attempting to generate electricity from the energy released in controlled thermonuclear fusion reactions, with a European fusion research roadmap stretching beyond 2050. Our current endeavors may culminate in a virtually inexhaustible, low-carbon energy source for future generations. LÄS MER

7. 25. Phase equilibria and thermodynamic properties of high-alloy tool steels : theoretical and experimental approach

   Författare :Johan Bratberg; John Ågren; Bengt Hallstedt; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; thermodynamic modelling; thermodynamic calculations; tool steels; high-speed steels; CALPHAD; Other materials science; Övrig teknisk materialvetenskap;

   Sammanfattning : The recent development of tool steels and high-speed steels has led to a significant increase in alloy additions, such as Co, Cr, Mo, N, V, and W. Knowledge about the phase relations in these multicomponent alloys, that is, the relative stability between different carbides or the solubility of different elements in the carbides and in the matrix phase, is essential for understanding the behaviour of these alloys in heat treatments. LÄS MER