TGFβ ligands belonging to the Activin/Nodal family, induces mesoderm and endoderm, specifies the embryonic axes, promotes gastrulation movements, maintains pluripotency of embryonic stem cells, and determines left-right asymmetry in vertebrates. Activin/Nodal ligands signal through type I and type II transmembrane serine/threonine kinase receptors. Ligand binding induces the formation of heteromeric receptor complexes in which type II receptors phosphorylate and activate type I receptors. The activated type I receptors transduce the signal inside the cell through the phosphorylation of th..
Climate change caused by increasing atmospheric CO2 is a major environmental problem of the 21st century. There has been much discussion about how to reduce CO2 output and prevent global warming. In this respect, plants are an important part of the overall picture as they are primary CO2 consumers and are directly challenged by increasing CO2 levels. Moreover, plants vary in their responses to elevated CO2. Plants that adapt better to this change are expected to out-compete their neighbors, which would cause instability in present ecosystems and unpredictable changes in weather and climate.In ..
The invention of the scanning tunnel microscope (STM) opened the door to nanoworld, enabling humankind to actually touch and feel the individual atoms at the surface of a material. It has inspired a series of inventions such as the atomic force microscope (AFM), the lateral force microscope (LFM), the magnetic force microscope (MFM), etc. Recently, the scanning probe microscope (SPM), which encompasses all these inventions, has evolved into the millipede technology which has a potential to make competing data storage technologies obsolete. A common denominator of these exciting developments is..
Spin-valve devices are a key component of a magnetoresistive random access memory. Mr. Woo Youn Kim and Professor Kwang Soo Kim of Department of Chemistry of POSTECH predicted supermagnetoresistance in a graphene nanoribbon device, the article of which has appeared in Nature Nanotech (3, 408-412, 2008). The reported graphene nanoribbon spin-valve device shows extremely large magnetoresistance (ten thousand times larger than that of conventional devices), which promises high speed access, and good sensitivity. The striking enhancement originates from the peculiar symmetry of band structures of ..
Improvements in performance and reductions in cost of silicon-based nonvolatile memories, such as flash random access memory (flash-RAM), have rendered floppy discs and many other forms of portable storage obsolete. But for many uses that require data to be written only once, such as archiving and security applications, their cost effectiveness is limited. So-called write-onceread- many (WORM) memories made from low-cost polymer materials could provide a solution. The devices, developed by Professors Moonhor Ree, Ohyun Kim, Su-Moon Park and their research teams, are based on hyperbranched copp..