360 research outputs found
The automatic computation for SUSY processes
We have constructed a system for the automatic computation of cross-sections
for the processes of the SUSY QED by the extension of the GRACE system
including a Majorana fermion. The system has also been applied to another model
including Majorana fermions, MSSM, by the definition of the model file.Comment: total 4 page
Cooperative functions of Hes/Hey genes in auditory hair cell and supporting cell development.
Notch-mediated lateral inhibition has been reported to regulate auditory hair cell and supporting cell development from common precursors. While the Notch effector genes Hes1, Hes5 and Hey1 are expressed in the developing cochlea, inactivation of either of them causes only mild abnormality, suggesting their functional redundancy. To explore the roles of Hes/Hey genes in cochlear development, we examined compound heterozygous or homozygous mutant mice that lacked Hes1, Hes5 and Hey1 alleles. We found that a reduction in Hes/Hey gene dosage led to graded increase of hair cell formation. However, if at least one allele of Hes1, Hes5 or Hey1 was intact, excessive hair cells were accompanied by overproduction of supporting cells, suggesting that the hair cell increase does not occur at the expense of supporting cells, and that each Hes/Hey gene functions to induce supporting cells. By contrast, when all alleles of Hes1, Hes5 and Hey1 were inactivated, the number of hair cells increased more drastically, whereas that of supporting cells was unchanged compared with control, suggesting that supporting cell formation was balanced by their overproduction and fate conversion into hair cells. The increase of the cell numbers seemed to occur after the prosensory domain formation in the mutants because the proliferation state and the size of the prosensory domain were not affected. Thus, Hes1, Hes5 and Hey1 cooperatively inhibit hair cell formation, and one allele of Hes1, Hes5 or Hey1 is sufficient for supporting cell production probably by lateral inhibition in the sensory epithelium. Strikingly, Hes/Hey mutations lead to disorganized cell alignment and polarity and to hearing loss despite hair cell overproduction. These results suggest that Hes/Hey gene dosage is essential not only for generation of appropriate numbers of hair cells and supporting cells by controlling cell proliferation and lateral inhibition but also for the hearing ability by regulating the cell alignment and polarity
Retrograde ERK activation waves drive base-to-apex multicellular flow in murine cochlear duct morphogenesis
うずまき管の伸⻑を司る分子活性と細胞群の波を発見 --綱引きによる細胞群の流れと臓器の成長--. 京都大学プレスリリース. 2021-03-09.A notable example of spiral architecture in organs is the mammalian cochlear duct, where the morphology is critical for hearing function. Genetic studies have revealed necessary signaling molecules, but it remains unclear how cellular dynamics generate elongating, bending, and coiling of the cochlear duct. Here, we show that extracellular signal-regulated kinase (ERK) activation waves control collective cell migration during the murine cochlear duct development using deep tissue live-cell imaging, Förster resonance energy transfer (FRET)-based quantitation, and mathematical modeling. Long-term FRET imaging reveals that helical ERK activation propagates from the apex duct tip concomitant with the reverse multicellular flow on the lateral side of the developing cochlear duct, resulting in advection-based duct elongation. Moreover, model simulations, together with experiments, explain that the oscillatory wave trains of ERK activity and the cell flow are generated by mechanochemical feedback. Our findings propose a regulatory mechanism to coordinate the multicellular behaviors underlying the duct elongation during development
Stalling interkinetic nuclear migration in curved pseudostratified epithelium of developing cochlea
The bending of epithelial tubes is a fundamental process in organ morphogenesis, driven by various multicellular behaviours. The cochlea in the mammalian inner ear is a representative example of spiral tissue architecture where the continuous bending of the duct is a fundamental component of its morphogenetic process. Although the cochlear duct morphogenesis has been studied by genetic approaches extensively, it is still unclear how the cochlear duct morphology is physically formed. Here, we report that nuclear behaviour changes are associated with the curvature of the pseudostratified epithelium during murine cochlear development. Two-photon live-cell imaging reveals that the nuclei shuttle between the luminal and basal edges of the cell is in phase with cell-cycle progression, known as interkinetic nuclear migration, in the flat region of the pseudostratified epithelium. However, the nuclei become stationary on the luminal side following mitosis in the curved region. Mathematical modelling together with perturbation experiments shows that this nuclear stalling facilitates luminal-basal differential growth within the epithelium, suggesting that the nuclear stalling would contribute to the bending of the pseudostratified epithelium during the cochlear duct development. The findings suggest a possible scenario of differential growth which sculpts the tissue shape, driven by collective nuclear dynamics
Histological Effect of Basic Fibroblast Growth Factor on Chronic Vocal Fold Scarring in a Rat Model
Objectives Vocal fold scarring is one of the most challenging laryngeal disorders to treat and there are currently no consistently effective treatments available. Our previous studies have shown the therapeutic potential of basic fibroblast growth factor (bFGF) for vocal fold scarring. However, the histological effects of bFGF on scarred vocal fold have not been elucidated. The aim of this study was to examine the histological effects of bFGF on chronic vocal fold scarring. Methods Sprague-Dawley rats were divided into phosphate buffered saline (sham) and bFGF groups. Unilateral vocal fold stripping was performed and the drug was injected into the scarred vocal fold for each group 2 months postoperatively. Injections were performed weekly for 4 weeks. Two months after the last injection, larynges were harvested and histologically analyzed. Results A significant increase of hyaluronic acid was observed in the vocal fold of the bFGF group compared with that of the sham group. However, there was no remarkable change in collagen expression nor in vocal fold contraction. Conclusion Significant increase of hyaluronic acid by local bFGF injection was thought to contribute to the therapeutic effects on chronic vocal fold scarring
Three-dimensional live imaging of Atoh1 reveals the dynamics of hair cell induction and organization in the developing cochlea
During cochlear development, hair cells (HCs) and supporting cells differentiate in the prosensory domain to form the organ of Corti, but how one row of inner HCs (IHCs) and three rows of outer HCs (OHCs) are organized is not well understood. Here, we investigated the process of HC induction by monitoring Atoh1 expression in cochlear explants of Atoh1-EGFP knock-in mouse embryos and showed that only the cells that express Atoh1 over a certain threshold are selected for HC fate determination. HC induction initially occurs at the medial edge of the prosensory domain to form IHCs and subsequently at the lateral edge to form OHCs, while Hedgehog signaling maintains a space between IHCs and OHCs, leading to formation of the tunnel of Corti. These results reveal dynamic Atoh1 expression in HC fate control and suggest that multi-directional signals regulate OHC induction, thereby organizing the prototype of the organ of Corti
PHASE, a Monte Carlo event generator for six-fermion physics at the LHC
PHASE is a new event generator dedicated to the study of Standard Model
processes with six fermions in the final state at the LHC. The code is intended
for analyses of vector boson scattering, Higgs search, three gauge boson
production, and top physics. This first version of the program describes final
states characterized by the presence of one neutrino, , at
O(). PHASE is based on a new iterative-adaptive multichannel
technique, and employs exact leading order matrix elements. The code can
generate unweighted events for any subset of all available final states. The
produced parton-level events carry full information on their colour and flavour
structure, enabling the evolution of the partons into fully hadronised final
states. An interface to hadronization packages is provided via the Les Houches
Protocol.Comment: 27 pages, Latex, 6 figure
Management of vocal fold lesions in difficult laryngeal exposure patients in phonomicrosurgery.
[Objectives]Endolaryngeal microsurgery using a direct laryngoscope is a well-established procedure in phonosurgery. Adequate laryngeal exposure is essential, but in some cases sufficient view of the glottis cannot be obtained, leading to treatment failure. This study reports how to manage vocal fold lesions in difficult laryngeal exposure (DLE) cases. [Methods]From 2003 to 2009, 212 patients underwent endolaryngeal microsurgery at Kyoto Medical Center and Kyoto University Hospital. Phonomicrosurgery was performed under sniffing (Boyce–Jackson) position with triangular shaped laryngoscope for laryngeal exposure. However, in DLE cases, the posture and laryngoscope were modified as needed to adequately expose the lesion. Fiberoptic laryngeal surgery (FLS) with local anesthesia was also used for the most difficult cases. [Results]The number of the patients with DLE was 14 (6.6%). Endolaryngeal microsurgery was possible in DLE cases by selecting the appropriate posture and laryngoscope. However, the procedure could not be completed in two patients with an anterior web and a vocal fold cyst, both of which required a subsequent revision procedure. Fiberoptic laryngeal surgery with topical anesthesia was a feasible alternative for these cases. [Conclusions]Phonosurgery was possible even in DLE cases. It is important to modify the setup of direct laryngoscopy as needed to obtain adequate exposure. Fiberoptic surgery may also be used in certain difficult cases
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