Mammalian epidermis is maintained by self-renewal of stem cells and terminal differentiation of their progeny. New data reveal a diversity amongst stem cells that was previously unrecognized. Different stem cell populations have different locations and differ in whether they are quiescent or actively cycling. During normal epidermal homeostasis, each stem cell population feeds a restricted numb...

The subgranular zone (SGZ) of the adult hippocampus contains a pool of quiescent neural progenitor cells (QNPs) that are capable of entering the cell cycle and producing newborn neurons. The mechanisms that control the timing and extent of adult neurogenesis are not well understood. Here, we show that QNPs of the adult SGZ express molecular-clock components and proliferate in a rhythmic fashion...

Accurate steady and unsteady numerical solutions of the full two-dimensional (2D) governing equations for the Nusselt problem (film condensation of quiescent saturated vapor on a vertical wall) are presented and related to known results. The problem, solved accurately up to film Reynolds number of 60 Re 60 , establishes various features of the well-known steady solution and reveals the interest...

4. Janssens W, Chuah MK, Naldini L, et al. Efficiency of onco-retroviral and lentiviral gene transfer into primary mouse and human B-lymphocytes is pseudotype dependent. Hum Gene Ther. 2003;14(3):263-276. 5. Serafini M, Naldini L, Introna M. Molecular evidence of inefficient transduction of proliferating human B lymphocytes by VSV-pseudotyped HIV-1-derived lentivectors. Virology. 2004;325(2):41...

The activity of adult stem cells is regulated by signals emanating from the surrounding tissue. Many niche signals have been identified, but it is unclear how they influence the choice of stem cells to remain quiescent or divide. Here we show that when stem cells of the adult hippocampus receive activating signals, they first induce the expression of the transcription factor Ascl1 and only subs...

Proliferation of the self-renewing epithelium of the gastric corpus occurs almost exclusively in the isthmus of the glands, from where cells migrate bidirectionally toward pit and base. The isthmus is therefore generally viewed as the stem cell zone. We find that the stem cell marker Troy is expressed at the gland base by a small subpopulation of fully differentiated chief cells. By lineage tra...

Quiescent current monitoring was developed as a testing strategy complementary to the traditional voltage test. A current test has the advantage that a test pattern may be easily generated and nearly every single and multiple physical faults are current-testable, on the other hand it is slowlier than a logic test since we have to wait for the transient currents to settle before performing the m...

We have identified two quiescent GRBs (bursts having two or more widelyseparated distinct emission episodes) in which the post-quiescent emission exhibits distinctly different characteristics than the pre-quiescent emission. In these two cases (BATSE GRBs 960530 and 980125), the second emission episode has a longer lag, a smoother morphology, and softer spectral evolution than the first episode...

AF8 cells were collected by mitotic detachment or made quiescent by serum restriction. Replated mitotic cells or serum-stimulated quiescent cells were then compared by flow cytofluorometry, when the use of acridine orange staining. Red fluorescence intensity (F greater than 600) was the same in quiescent cells and in cells immediately after mitosis. However, F greater than 600 increased very ra...