1,788 research outputs found

    Upper lip swelling caused by a large dentigerous cyst

    Get PDF
    Swelling of the upper lip can result from various diseases such as salivary tumors, infectious and inflammatory diseases and cysts. Among the latter, dentigerous cysts, typically involving unerupted teeth, are sometimes associated with supernumerary teeth in the maxillary anterior incisors region called the mesiodens. We report an unusual case of a large dentigerous cyst associated with an impacted mesiodens in a 42-year-old male who presented with a slow-growing swelling in the upper li

    Extremal properties for dissections of convex 3-polytopes

    Get PDF
    A dissection of a convex d-polytope is a partition of the polytope into d-simplices whose vertices are among the vertices of the polytope. Triangulations are dissections that have the additional property that the set of all its simplices forms a simplicial complex. The size of a dissection is the number of d-simplices it contains. This paper compares triangulations of maximal size with dissections of maximal size. We also exhibit lower and upper bounds for the size of dissections of a 3-polytope and analyze extremal size triangulations for specific non-simplicial polytopes: prisms, antiprisms, Archimedean solids, and combinatorial d-cubes.Comment: 19 page

    The ubiquitin ligase LIN41/TRIM71 targets p53 to antagonize cell death and differentiation pathways during stem cell differentiation

    Get PDF
    Rapidity and specificity are characteristic features of proteolysis mediated by the ubiquitin-proteasome system. Therefore, the UPS is ideally suited for the remodeling of the embryonic stem cell proteome during the transition from pluripotent to differentiated states and its inverse, the generation of inducible pluripotent stem cells. The Trim-NHL family member LIN41 is among the first E3 ubiquitin ligases to be linked to stem cell pluripotency and reprogramming. Initially discovered in C. elegans as a downstream target of the let-7 miRNA, LIN41 is now recognized as a critical regulator of stem cell fates as well as the timing of neurogenesis. Despite being indispensable for embryonic development and neural tube closure in mice, the underlying mechanisms for LIN41 function in these processes are poorly understood. To better understand the specific contributions of the E3 ligase activity for the stem cell functions of LIN41, we characterized global changes in ubiquitin or ubiquitin-like modifications using Lin41-inducible mouse embryonic stem cells. The tumor suppressor protein p53 was among the five most strongly affected proteins in cells undergoing neural differentiation in response to LIN41 induction. We show that LIN41 interacts with p53, controls its abundance by ubiquitination and antagonizes p53-dependent pro-apoptotic and pro-differentiation responses. In vivo, the lack of LIN41 is associated with upregulation of Grhl3 and widespread caspase-3 activation, two downstream effectors of p53 with essential roles in neural tube closure. As Lin41-deficient mice display neural tube closure defects, we conclude that LIN41 is critical for the regulation of p53 functions in cell fate specification and survival during early brain development

    Responsibility Under Uncertainty: Which Climate Decisions Matter Most?

    Get PDF
    We propose a new method for estimating how much decisions under monadic uncertainty matter. The method is generic and suitable for measuring responsibility in finite horizon sequential decision processes. It fulfills “fairness” requirements and three natural conditions for responsibility measures: agency, avoidance and causal relevance. We apply the method to study how much decisions matter in a stylized greenhouse gas emissions process in which a decision maker repeatedly faces two options: start a “green” transition to a decarbonized society or further delay such a transition. We account for the fact that climate decisions are rarely implemented with certainty and that their consequences on the climate and on the global economy are uncertain. We discover that a “moral” approach towards decision making — doing the right thing even though the probability of success becomes increasingly small — is rational over a wide range of uncertainties

    Application of the extended P+QQ force model to N≈ZN \approx Z fp shell nuclei

    Full text link
    To study collective motion, the extended pairing plus QQQQ force model proposed recently is applied to AA=46, 48 and 50 nuclei in the fpfp shell region. Exact shell model calculations in the truncated model space (f7/2,p3/2,p1/2)(f_{7/2},p_{3/2},p_{1/2}) prove the usefulness of the interaction. The simple model with the pairing plus quadrupole pairing plus QQQQ force and JJ-independent isoscalar proton-neutron force reproduces unexpectedly well observed binding energies, energy levels of collective (yrast) states and reduced E2E2 transition probabilities in 46^{46}Ti, 46^{46}V, 48^{48}V, 48^{48}Cr, 50^{50}Cr and 50^{50}Mn. The correspondence between theory and experiment is almost comparable to that attained by the full fpfp shell model calculations with realistic effective interactions. Some predictions are made for energy levels and variations of B(E2)B(E2) in the yrast bands, in these nuclei. Characteristics of the interaction are investigated by comparing with the realistic effective interactions.Comment: 34 pages including 14 figure
    • 

    corecore