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Function of the Neuromuscular Junction
A neuromuscular junction (NMJ) is the synapse or junction of the axon terminal of a motoneuron with the motor end plate, the highly-excitable region of muscle fiber plasma membrane responsible for initiation of action potentials across the muscle's surface, ultimately causing the muscle to contract. In vertebrates, the signal passes through the neuromuscular junction via the neurotransmitter acetylcholine. Anatomy When a motor neuron enters a muscle, it loses its myelin sheath and splits into many terminal branches. Motor neuron (efferent) axons originating in the spinal cord enter muscle fibers, where they split into many unmyelinated branches.
Research raises doubts about whether modern humans and Neanderthals interbred
Aug. 13, 2012 — New research raises questions about the theory that modern humans and Neanderthals at some point interbred, known as hybridisation. The findings of a study by researchers at the University of Cambridge suggest that common ancestry, not hybridisation, better explains the average 1-4 per cent DNA that those of European and Asian descent (Eurasians) share with Neanderthals.
The great milk robbery: How corporations are stealing livelihoods and a vital source of nutrition from the poor
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Actualités des derniers jours La Corée du Nord se déclare en état de guerre contre son voisin du sud
Toutes les populations du monde
El cambio climático está causando un nuevo tipo de pobreza.
Desplazados por el cambio climático | Ciencia
Réfugiés climatiques : les mouvements de population s'accélèrent
20 millions de réfugiés climatiques en 2008, un milliard en 2050 ?! info + Une conférence sur le thème "Gérer le Changement Climatique" se déroulera à Paris au Collège de France les 7 et 8 juin 2010.Understanding Climate's Influence on Human Evolution
Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
From the oceans to continental heartlands, human activities have altered the physical characteristics of Earth's surface.
