In this paper we study quasi-stationarity for a large class of Kolmogorov diffusions. The main novelty here is that we allow the drift to go to−∞at the origin, and the diffusion to have an entrance boundary at +∞. These diffusions arise as images, by a deterministic map, of generalized Feller diffusions, which themselves are obtained as limits of rescaled birth–death processes. Generalized Feller diffusions take nonnegative values and are absorbed at zero in finite time with probability 1. An important example is the logistic Feller diffusion. We give sufficient conditions on the drift near 0 and near +∞ for the existence of quasi-stationary distributions, as well as rate of convergence in the Yaglom limit and existence of the Q-process. We also show that, under these conditions, there is exactly one quasi-stationary distribution, and that this distribution attracts all initial distributions under the conditional evolution, if and only if +∞ is an entrance boundary. In particular, this gives a sufficient condition for the uniqueness of quasi-stationary distributions. In the proofs spectral theory plays an important role on L2 of the reference measure for the killed process

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Gross chromosomal rearrangements (GCRs) play an important role in human diseases, including cancer. The identity of all Genome Instability Suppressing (GIS) genes is not currently known. Here multiple Saccharomyces cerevisiae GCR assays and query mutations were crossed into arrays of mutants to identify progeny with increased GCR rates. One hundred eighty two GIS genes were identified that suppressed GCR formation. Another 438 cooperatively acting GIS genes were identified that were not GIS genes, but suppressed the increased genome instability caused by individual query mutations. Analysis of TCGA data using the human genes predicted to act in GIS pathways revealed that a minimum of 93% of ovarian and 66% of colorectal cancer cases had defects affecting one or more predicted GIS gene. These defects included loss-of-function mutations, copy-number changes associated with reduced expression, and silencing. In contrast, acute myeloid leukaemia cases did not appear to have defects affecting the predicted GIS genes.

Disorders in skin wound healing are a major health problem that requires the development of innovative treatments. The use of biomaterials as an alternative of skin replacement has become relevant, but its use is still limited due to poor vascularization inside the scaffolds, resulting in insufficient oxygen and growth factors at the wound site. In this study, we have developed a cell-based wound therapy consisting of the application of collagen-based dermal scaffolds containing mesenchymal stem cells from Wharton's jelly (WJ-MSC) in an immunocompetent mouse model of angiogenesis. From our comparative study on the secretion profile between WJ-MSC and adipose tissue-derived MSC, we found a stronger expression of several well-characterized growth factors, such as VEGF-A, angiopoietin-1 and aFGF, which are directly linked to angiogenesis, in the culture supernatant of WJ-MSC, both on monolayer and 3D culture conditions. WJ-MSC proved to be angiogenic both in vitro and in vivo, through tubule formation and CAM assays, respectively. Moreover, WJ-MSC consistently improved the healing response in vivo in a mouse model of human-like dermal repair, by triggering angiogenesis and further providing a suitable matrix for wound repair, without altering the inflammatory response in the animals. Since these cells can be easily isolated, cultured with high expansion rates and cryopreserved, they represent an attractive stem cell source for their use in allogeneic cell transplant and tissue engineering.