You may have to Search all our reviewed books and magazines, click the sign up button below to create a free account.
Cancer is characterized by heterogeneous cells with capacity for self renewal, and selective pressures in the microenvironment which constantly change the cell population. This "descent with modification" is consistent with Darwin's definition of evolution, and accordingly, cancer progression can be captured from an evolutionary angle. However, there is also a clear difference between cancer progression and biological evolution. First, contrary to the evolution of complex organisms, cancer originates from cells of multicellular organisms that escape their constraints and behave like unicellular organisms. Therefore, from the beginning, cancer cells have complex genomes that contain abundant genetic materials which they can use to change their phenotype by dynamic rearrangements and modifications. Secondly, epigenetic effects promote cancer evolution in contrast to the evolution of life. Some tumors develop with minimal genetic alterations, and cell plasticity contributes to both initiation and progression in various tumors. However, an evolutionary theory that encompasses these characteristics of cancer remains to be developed.
None
Wie wird international und in der Schweiz Mathematik unterrichtet? Welche Gemeinsamkeiten und Unterschiede zeigen sich? Zeichnen sich Mathematikstunden aus Ländern, deren Schülerinnen und Schüler in Leistungstests besonders gut abschneiden, durch besondere Gestaltungs- und Qualitätsmerkmale aus? Was lässt sich über Merkmale guter Unterrichtsqualität aus der Perspektive von Schülerinnen und Schülern, Lehrpersonen und aussenstehenden Experten aussagen? Wie wirken sich didaktische Gestaltungsmerkmale, Lernmotivation und Selbstvertrauen auf Fachinteresse, Engagement und Leistungen aus? Antworten auf diese und weitere Fragen suchten zwei Videostudien, deren Ergebnisse in diesem Band vorg...