91 research outputs found

    On zero sets in the Dirichlet space

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    We study the zeros sets of functions in the Dirichlet space. Using Carleson formula for Dirichlet integral, we obtain some new families of zero sets. We also show that any closed subset of E \subset \TT with logarithmic capacity zero is the accumulation points of the zeros of a function in the Dirichlet space. The zeros satisfy a growth restriction which depends on EE.Comment: Journal of Geometric Analysis (2011

    Constructive approximation in de Branges-Rovnyak spaces

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    In most classical holomorphic function spaces on the unit disk, a function ff can be approximated in the norm of the space by its dilates f\_r(z):=f(rz)~(r \textless{} 1). We show that this is \emph{not} the case for the de Branges--Rovnyak spaces \cH(b). More precisely, we give an example of a non-extreme point bb of the unit ball of H∞H^\infty and a function f\in\cH(b) such that \lim\_{r\to1^-}\|f\_r\|\_{\cH(b)}=\infty. It is known that, if bb is a non-extreme point of the unit ball of H∞H^\infty, then polynomials are dense in \cH(b). We give the first constructive proof of this fact

    Early post-transplant urinary IP-10 expression after kidney transplantation is predictive of short- and long-term graft function

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    The early identification of renal transplant recipients at enhanced risk of developing acute and subclinical rejection would allow individualized adjustment of immunosuppression before functional graft injury occurs and would exclude these patients from drug-weaning studies. Protein and reverse transcriptase-polymerase chain reaction-based analyses of candidate markers in urine open the opportunity to closely monitor kidney-transplanted patients non-invasively. The chemokine interferon-inducible protein 10 (IP-10; CXCL10) might be an interesting candidate to uncover ongoing immune processes within the graft. Urine samples from kidney-transplanted recipients were retrospectively analyzed for IP-10 mRNA and protein expression. IP-10 levels were correlated with the incidence of acute rejection episodes proven by histology and long-term graft function assessed by the glomerular filtration rate 6 months post transplantation. IP-10 expression in urine identified patients with ongoing acute rejection episodes several days before a biopsy was indicated by rising serum creatinine levels. Most importantly, elevated levels of urinary IP-10 protein within the first four postoperative weeks were predictive of graft function at 6 months even in the absence of acute rejection. These data reveal a correlation between elevated IP-10 expression in urine at early time points post-transplantation and intragraft immune activation that leads to acute rejection and compromised long-term graft function

    Mechanical forces couple bone matrix mineralization with inhibition of angiogenesis to limit adolescent bone growth

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    Bone growth requires a specialised, highly angiogenic blood vessel subtype, so-called type H vessels, which pave the way for osteoblasts surrounding these vessels. At the end of adolescence, type H vessels differentiate into quiescent type L endothelium lacking the capacity to promote bone growth. Until now, the signals that switch off type H vessel identity and thus limit adolescent bone growth have remained ill defined. Here we show that mechanical forces, associated with increased body weight at the end of adolescence, trigger the mechanoreceptor PIEZO1 and thereby mediate enhanced production of the kinase FAM20C in osteoblasts. FAM20C, the major kinase of the secreted phosphoproteome, phosphorylates dentin matrix protein 1, previously identified as a key factor in bone mineralization. Thereupon, dentin matrix protein 1 is secreted from osteoblasts in a burst-like manner. Extracellular dentin matrix protein 1 inhibits vascular endothelial growth factor signalling by preventing phosphorylation of vascular endothelial growth factor receptor 2. Hence, secreted dentin matrix protein 1 transforms type H vessels into type L to limit bone growth activity and enhance bone mineralization. The discovered mechanism may suggest new options for the treatment of diseases characterised by aberrant activity of bone and vessels such as osteoarthritis, osteoporosis and osteosarcoma

    Discrete populations of isotype-switched memory B lymphocytes are maintained in murine spleen and bone marrow

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    At present, it is not clear how memory B lymphocytes are maintained over time, and whether only as circulating cells or also residing in particular tissues. Here we describe distinct populations of isotype-switched memory B lymphocytes (Bsm) of murine spleen and bone marrow, identified according to individual transcriptional signature and B cell receptor repertoire. A population of marginal zone-like cells is located exclusively in the spleen, while a population of quiescent Bsm is found only in the bone marrow. Three further resident populations, present in spleen and bone marrow, represent transitional and follicular B cells and B1 cells, respectively. A population representing 10-20% of spleen and bone marrow memory B cells is the only one qualifying as circulating. In the bone marrow, all cells individually dock onto VCAM1+ stromal cells and, reminiscent of resident memory T and plasma cells, are void of activation, proliferation and mobility

    Standard of insurance procedures and risk assessment manual for cold water fish culture regarding management and natural disasters

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    The total production of Rainbow trout fish aquaculture in 2009 had been 72515 t which was significantly increased (91519 t) in 2010. Despite of increasing trout fish production during last decade, absence conformity between suitable cultural and proliferation district of this fish species and geographical one, faced this industry harmfully to natural disasters such as flood, overflow and so on, and mismanagement due to human injustices. Hence insurance and supporting concept of can be having a determinant role in efflorescence and increasing production of this fish. The aim of this project is performing an insurance policy based on risk analysis model in propagation and cultural phases of rainbow trout aquaculture, separately. In this study, pay attention to standards in trout fish aquaculture procedure and determination of critical parameters on, are the first research step and recognition of risk factors in different aquaculture phases due to natural disasters and mismanagement, from the brood stock maintenance till reach to 3-5 g fingerling and finally market size fishes, are the following research steps. After determination of proportion percentages of each parameters regarding to arise the risk, analysis risks and risk management were done for trout fish aquaculture. Three provinces, Fars, Mazandaran and Charmahal Bakhtiary as poles production of trout fish were chosen as delegates of the whole Iran and insurance ability of trout fish hatcheries and aquaculture farms were done. Trout aquaculture standardization were obtained, natural disasters and mismanagement affected on aquaculture activities were recognized (Chapters 1 and 3) and due to importance of health and disease of trout fish, mortality causes and audit signs of also determined and analyzed (Chapter 2) . In Chapter 4, trout farms degraded and fix and natural disasters for trout fish brood stock, propagation hatcheries and cultural farms were analyzed and accounted. Finally, premium and recompense were accounted for hatchery and farm separately

    A pulmonologist's guide to perform and analyse cross-species single lung cell transcriptomics

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    Single-cell ribonucleic acid sequencing is becoming widely employed to study biological processes at a novel resolution depth. The ability to analyse transcriptomes of multiple heterogeneous cell types in parallel is especially valuable for cell-focused lung research where a variety of resident and recruited cells are essential for maintaining organ functionality. We compared the single-cell transcriptomes from publicly available and unpublished datasets of the lungs in six different species: human (Homo sapiens), African green monkey (Chlorocebus sabaeus), pig (Sus domesticus), hamster (Mesocricetus auratus), rat (Rattus norvegicus) and mouse (Mus musculus) by employing RNA velocity and intercellular communication based on ligand-receptor co-expression, among other techniques. Specifically, we demonstrated a workflow for interspecies data integration, applied a single unified gene nomenclature, performed cell-specific clustering and identified marker genes for each species. Overall, integrative approaches combining newly sequenced as well as publicly available datasets could help identify species-specific transcriptomic signatures in both healthy and diseased lung tissue and select appropriate models for future respiratory research
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