105 research outputs found

    Short-type PB-cadherin promotes survival of gonocytes and activates JAK-STAT signalling

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    AbstractNeonatal development of the rat testis involves a number of critical events including re-entry of gonocytes into the cell cycle and eventual loss of many of these cells and their progeny via apoptosis. Since surviving gonocytes give rise to subsequent generations of germ cells, regulation of their fate is critical for adult testicular function. Here, we have identified a role for short-type PB-cadherin (STPB-C) in promoting survival of gonocytes in neonatal rats and we have linked its expression to the JAK-STAT signaling pathway. These findings were obtained with varied approaches including use of transgenic rats overexpressing STPB-C which were studied with protein microarrays and other techniques, direct examination of germ cell apoptosis and survival in gonocyte–Sertoli cell co-cultures, and direct study of the JAK-STAT pathway in these models and in L cells transfected with STPB-C. These data provide new information on the regulation of gonocyte fate and exciting new evidence supporting a link between the JAK-STAT pathway and cadherin-based cell–cell interactions

    Orthopedic management of the extremities in patients with Morquio A syndrome.

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    BackgroundMusculoskeletal involvement in Morquio A syndrome (mucopolysaccharidosis IVA; MPS IVA) contributes significantly to morbidity and mortality. While the spinal manifestations of the disorder have received considerable attention in the literature, there have been few reported studies to date to guide the management of the orthopedic problems associated with the lower and upper extremities.PurposeThe objective was to develop recommendations for the management of the extremities in patients with Morquio A syndrome.MethodsA group of specialists in orthopedics, pediatrics and genetics with experience in the management of Morquio A patients convened to review and discuss current clinical practices and to develop preliminary recommendations. Evidence from the literature was retrieved. Recommendations were further refined until consensus was reached.Results and conclusionsThis present article provides a detailed review and discussion of the lower and upper extremity deformities in Morquio A syndrome and presents recommendations for the assessment and treatment of these complications. Key issues, including the importance of early diagnosis and the implications of medical therapy, are also addressed. The recommendations herein represent an attempt to develop a uniform and practical approach to managing patients with Morquio A syndrome and improving their outcomes

    Epithelial Migration and Non-adhesive Periderm Are Required for Digit Separation during Mammalian Development.

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    The fusion of digits or toes, syndactyly, can be part of complex syndromes, including van der Woude syndrome. A subset of van der Woude cases is caused by dominant-negative mutations in the epithelial transcription factor Grainyhead like-3 (GRHL3), and Grhl3-/-mice have soft-tissue syndactyly. Although impaired interdigital cell death of mesenchymal cells causes syndactyly in multiple genetic mutants, Grhl3-/- embryos had normal interdigital cell death, suggesting alternative mechanisms for syndactyly. We found that in digit separation, the overlying epidermis forms a migrating interdigital epithelial tongue (IET) when the epithelium invaginates to separate the digits. Normally, the non-adhesive surface periderm allows the IET to bifurcate as the digits separate. In contrast, in Grhl3-/- embryos, the IET moves normally between the digits but fails to bifurcate because of abnormal adhesion of the periderm. Our study identifies epidermal developmental processes required for digit separation

    Stochastic `Beads on a String' in the Accretion Tail of Arp 285

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    We present Spitzer infrared, GALEX UV, and SDSS and SARA optical images of the peculiar interacting galaxy pair Arp 285 (NGC 2856/4), and compare with a new numerical model of the interaction. We estimate the ages of clumps of star formation in these galaxies using population synthesis models, carefully considering the uncertainties on these ages. This system contains a striking example of `beads on a string': a series of star formation complexes ~1 kpc apart. These `beads' are found in a tail-like feature that is perpendicular to the disk of NGC 2856, which implies that it was formed from material accreted from the companion NGC 2854. The extreme blueness of the optical/UV colors and redness of the mid-infrared colors implies very young stellar ages (~4 - 20 Myrs) for these star forming regions. Spectral decomposition of these `beads' shows excess emission above the modeled stellar continuum in the 3.6 micron and 4.5 micron bands, indicating either contributions from interstellar matter to these fluxes or a second older stellar population. These clumps have -12.0 < M(B) < -10.6, thus they are less luminous than most dwarf galaxies. Our model suggests that bridge material falling into the potential of the companion overshoots the companion. The gas then piles up at apo-galacticon before falling back onto the companion, and star formation occurs in the pile-up. A luminous (M(B) ~ -13.6) extended (FWHM ~ 1.3 kpc) `bright spot' is visible at the northwestern edge of the NGC 2856 disk, with an intermediate stellar population (400 - 1500 Myrs). Our model suggests that this feature is part of a expanding ripple-like `arc' created by an off-center ring-galaxy-like collision between the two disks.Comment: Accepted by the Astronomical Journal. For color figures and appendix material, go tohttp://www.etsu.edu/physics/bsmith/research/sg/arp285/arp285.htm

    Autonomous Aircraft Rescue Firefighting Vehicle: Speedfest 2022 Charlie Div. Team 2

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    Aircraft fires are dangerous and can get out of control quickly. Due to the size of modern day aircraft, they can hold a large amount of fuel. This leads to a larger and hotter fire, one in fact that may be difficult for humans to approach. To decrease the risk of human life the implementation of autonomy to firefighting vehicles might be the solution.In this article, one will find the complete background, design and manufacturing processes, as well as future plans for this concept to become a reality. A team of eight engineering technology students have put together ideas, experience and effort to propose a hopeful execution for the Autonomous Aircraft Rescue Firefighting Vehicle. One will find throughout this paper that many types of data have been collected, analyses have been run, and investigative research conducted. Programming, wiring, welding, machining, and testing are among several things that have contributed to the progress of this project. Over the course of ten months, amongst complexities and successes, Team Fax is attempting to solve this real-world problem of dangerous aircraft fires. To demonstrate this concept at a scaled size, the team has competed in the Oklahoma State University 2022 Speedfest Competition. The competition required the AARFF vehicle to navigate a course of cones based on GPS locations as well as locating and extinguishing a type A jet fuel fire

    Sloan Digital Sky Survey Imaging of Low Galactic Latitude Fields: Technical Summary and Data Release

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    The Sloan Digital Sky Survey (SDSS) mosaic camera and telescope have obtained five-band optical-wavelength imaging near the Galactic plane outside of the nominal survey boundaries. These additional data were obtained during commissioning and subsequent testing of the SDSS observing system, and they provide unique wide-area imaging data in regions of high obscuration and star formation, including numerous young stellar objects, Herbig-Haro objects and young star clusters. Because these data are outside the Survey regions in the Galactic caps, they are not part of the standard SDSS data releases. This paper presents imaging data for 832 square degrees of sky (including repeats), in the star-forming regions of Orion, Taurus, and Cygnus. About 470 square degrees are now released to the public, with the remainder to follow at the time of SDSS Data Release 4. The public data in Orion include the star-forming region NGC 2068/NGC 2071/HH24 and a large part of Barnard's loop.Comment: 31 pages, 9 figures (3 missing to save space), accepted by AJ, in press, see http://photo.astro.princeton.edu/oriondatarelease for data and paper with all figure
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