Classical Marxism

Classical Marxism refers to the body of theory directly expounded by Karl Marx and Friedrich Engels. The term "Classical Marxism" is often used to distinguish between "Marxism" as it is broadly understood and "what Marx believed", which is not necessarily the same thing. For example, shortly before he died in 1883, Marx wrote a letter to the French workers' leader Jules Guesde and to his own son-in-law Paul Lafargue, both of whom claimed to represent Marxist principles, in which he accused them of "revolutionary phrase-mongering" and of denying the value of reformist struggles. Paraphrasing Marx: "If that is Marxism, then I am not a Marxist". As the American Marx scholar Hal Draper remarked, "there are few thinkers in modern history whose thought has been so badly misrepresented, by Marxists and anti-Marxists alike."

Nuclear transport

The entry and exit of large molecules from the nucleus is tightly controlled by the nuclear pore complexes. Although small molecules can enter the nucleus without regulation, macromolecules such as RNA and proteins require association karyopherins called importins to enter the nucleus and exportins to exit. "Cargo" proteins that must be translocated from the cytoplasm to the nucleus contain short amino acid sequences known as nuclear localization signals which are bound by importins, while those transported from the nucleus to the cytoplasm carry nuclear export signals bound by exportins. The ability of importins and exportins to transport their cargo is regulated by GTPases, enzymes that hydrolyze the molecule guanosine triphosphate to release energy. The key GTPase in nuclear transport is Ran, which can bind either GTP or GDP (guanosine diphosphate) depending on whether it is located in the nucleus or the cytoplasm.

Comparative psychology

Comparative psychology refers to the study of the behavior and mental life of animals other than human beings. It is related to disciplines outside of psychology that study animal behavior, such as ethology. Although the field of psychology is primarily concerned with humans, the behavior and mental processes of animals is also an important part of psychological research, either as a subject in its own right (e.g., animal cognition and ethology), or with strong emphasis about evolutionary links, and somewhat more controversially, as a way of gaining an insight into human psychology by means of comparison or via animal models of emotional and behavior systems as seen in neuroscience of psychology .

Cosmology

Cosmology is the branch of metaphysics that deals with the world as the totality of all phenomena in space and time. Historically, it has had quite a broad scope, and in many cases was founded in religion. The ancient Greeks did not draw a distinction between this use and their model for the cosmos. However, in modern use it addresses questions about the Universe which are beyond the scope of physical science. It is distinguished from religious cosmology in that it approaches these questions using philosophical methods (e.g. dialectics). Cosmogony deals specifically with the origin of the universe.