311,409 research outputs found
Solid hulls and cores of weighted H-infinity-spaces
No full text[EN] We determine the solid hull and solid core of weighted Banach spaces H-upsilon(infinity) of analytic functions functions f such that upsilon vertical bar f vertical bar is bounded, both in the case of the holomorphic functions on the disc and on the whole complex plane, for a very general class of radial weights upsilon. Precise results are presented for concrete weights on the disc that could not be treated before. It is also shown that if H-upsilon(infinity) is solid, then the monomials are an (unconditional) basis of the closure of the polynomials in H-upsilon(infinity). As a consequence H-upsilon(infinity) does not coincide with its solid hull and core in the case of the disc. An example shows that this does not hold for weighted spaces of entire functions.The research of Bonet was partially supported by the project MTM2016-76647-P. The research of Taskinen was partially supported by the Vaisala Foundation of the Finnish Academy of Sciences and Letters.Bonet Solves, JA.; Lusky, W.; Taskinen, J. (2018). Solid hulls and cores of weighted H-infinity-spaces. Revista Matemática Complutense. 31(3):781-804. https://doi.org/10.1007/s13163-018-0265-6S781804313Anderson, J.M., Shields, A.L.: Coefficient multipliers of Bloch functions. Trans. Am. Math. Soc. 224, 255–265 (1976)Bennet, G., Stegenga, D.A., Timoney, R.M.: Coefficients of Bloch and Lipschitz functions. Ill. J. Math. 25, 520–531 (1981)Bierstedt, K.D., Bonet, J., Galbis, A.: Weighted spaces of holomorphic functions on bounded domains. Mich. Math. J. 40, 271–297 (1993)Bierstedt, K.D., Bonet, J., Taskinen, J.: Associated weights and spaces of holomorphic functions. Stud. Math. 127, 137–168 (1998)Blasco, O., Galbis, A.: On Taylor coefficients of entire functions integrable against exponential weights. Math. Nachr. 223, 5–21 (2001)Blasco, O., Pavlovic, M.: Coefficient multipliers on Banach spaces of analytic functions. Rev. Mat. Iberoam. 27, 415–447 (2011)Bonet, J., Taskinen, J.: Solid hulls of weighted Banach spaces of entire functions. Rev. Mat. Iberoam. 34, 593–608 (2018)Bonet, J., Taskinen, J.: Solid hulls of weighted Banach spaces of analytic functions on the unit disc with exponential weights. Ann. Acan. Sci. Fenn. Math. 43, 521–530 (2018)Constantin, O., Peláez, J.A.: Boundedness of the Bergman projection on L p -spaces with exponential weights. Bull. Sci. Math. 139(3), 245–268 (2015)Dostanić, M.R.: Multipliers in the space of analytic functions with exponential mean growth. Asymptot. Anal. 65(3–4), 191–201 (2009)Dostanić, M.-R.: Integration operators on Bergman spaces with exponential weight. Rev. Mat. Iberoam. 23(2), 421–436 (2007)Jevtić, M., Pavlović, M.: On the solid hull of the Hardy-Lorentz space. Publ. Inst. Math. (Beogr.) (N.S.) 85(99), 55–61 (2009)Jevtić, M., Vukotić, D., Arsenović, M.: Taylor Coefficients and Coefficient Multipliers of Hardy and Bergman-Type Spaces. RSME Springer Series, vol. 2. Springer, Berlin (2016)Lindenstrauss, J., Tzafriri, L.: Classical Banach Spaces I. Springer, Berlin (1977)Lusky, W.: On the Fourier series of unbounded harmonic functions. J. Lond. Math. Soc. 2(61), 568–580 (2000)Lusky, W.: On the isomorphism classes of weighted spaces of harmonic and holomorphic functions. Stud. Math. 175, 19–45 (2006)Pau, J., Peláez, J.A.: Volterra type operators on Bergman spaces with exponential weights. Contemp. Math. 561, 239–252. Topics in complex analysis and operator theory. American Mathematical Society, Providence (2012)Pavlović, M.: On harmonic conjugates with exponential mean growth. Czech. Math. J. 49, 733–742 (1999)Pavlović, M.: Function Classes on the Unit Disc: An Introduction. De Gruyter Studies in Mathematics, vol. 52, p. 449. De Gruyter, Berlin (2014)Peláez, J.A., Rättyä, J.: Weighted Bergman Spaces Induced by Rapidly Increasing Weights, vol. 227, no. 1066, pp. vi+124. American Mathematical Society (2014)Shields, A.L., Williams, D.L.: Bounded projections, duality and multipliers in spaces of analytic functions. Trans. Am. Math. Soc. 162, 287–302 (1971
Solid hulls of weighted Banach spaces of entire functions
No full text[EN] Given a continuous, radial, rapidly decreasing weight v on the complex plane, we study the solid hull of its associated weighted space H¿v(C) of all the entire functions f such that v|f| is bounded. The solid hull is found for a large class of weights satisfying the condition (B) of Lusky. Precise formulations are obtained for weights of the form v(r)= exp(¿arp),a>0,p>0. Applications to spaces of multipliers are included.The research of Bonet was partially supported by MTM2013-43540-P, GVA Prometeo II/2013/013 and GVA ACOMP/2015/186. The research of Taskinen was partially supported by the Magnus Ehrnrooth and the Vaisala Foundations.Bonet Solves, JA.; Taskinen, J. (2018). Solid hulls of weighted Banach spaces of entire functions. Revista Matemática Iberoamericana. 34(2):593-608. https://doi.org/10.4171/RMI/996S59360834
Serum cholesterol levels in neutropenic patients with fever
No full textHypocholesterolemia, which often accompanies infectious diseases has been suggested to serve as a prognostic marker in hospitalized patients. Even though patients with chemotherapyinduced leukopenia are at high risk of infection and mortality, only limited information is available on serum cholesterol levels in these patients. We therefore measured serum cholesterol levels in 17 patients with hematological malignancies during chemotherapyinduced neutropenia and correlated it with clinical outcome. Patients with fever (>38.5 degreesC) showed a significant decrease in serum cholesterol levels within 24 hours. Eight days after onset of the fever nonsurvivors had significantly lower serum cholesterol levels (median 2.09 mmol/l, range 0.492.79, n=6) compared to survivors (median 3.23 mmol/l, range 1.684.86, n=11). Cholesterol levels in survivors returned to baseline levels at the time of discharge from the hospital. At the onset of fever, serum levels of inflammatory cytokines interleukin-6, tumor necrosis factor (TNF) and soluble TNF receptors p55 and p75 were elevated in all patients, but only TNF and TNF receptor p75 levels were significantly different in survivors and nonsurvivors. Our data suggest that a decrease in serum cholesterol levels is a prognostic marker in neutropenic patients with fever. Release of inflammatory cytokines may in part be responsible for hypocholesterolemia in these patients
PPAR alpha: an emerging therapeutic target in diabetic microvascular damage
No full textThe global pandemic of diabetes mellitus portends an alarming rise in the prevalence of microvascular complications, despite advanced therapies for hyperglycemia, hypertension and dyslipidemia. Peroxisome proliferator-activated receptor alpha (PPAR alpha) is expressed in organs affected by diabetic microvascular disease (retina, kidney and nerves), and its expression is regulated specifically in these tissues. Experimental evidence suggests that PPAR alpha activation attenuates or inhibits several mediators of vascular damage, including lipotoxicity, inflammation, reactive oxygen species generation, endothelial dysfunction, angiogenesis and thrombosis, and thus might influence intracellular signaling pathways that lead to microvascular complications. PPAR alpha has emerged as a novel target to prevent microvascular disease, via both its lipid-related and lipid-unrelated actions. Despite strong experimental evidence of the potential benefits of PPAR alpha agonists in the prevention of vascular damage, the evidence from clinical studies in patients with diabetes mellitus remains limited. Promising findings from the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study on microvascular outcomes are countered by elevations in participants' homocysteine and creatinine levels that might potentially attenuate the benefits of PPAR alpha activation. This Review focuses on the role of PPAR alpha activation in diabetic microvascular disease and highlights the available experimental and clinical evidence from studies of PPAR alpha agonists
Why Is Apolipoprotein CIII Emerging as a Novel Therapeutic Target to Reduce the Burden of Cardiovascular Disease?
No full textApoC-III was discovered almost 50 years ago, but for many years, it did not attract much attention. However, as epidemiological and Mendelian randomization studies have associated apoC-III with low levels of triglycerides and decreased incidence of cardiovascular disease (CVD), it has emerged as a novel and potentially powerful therapeutic approach to managing dyslipidemia and CVD risk. The atherogenicity of apoC-III has been attributed to both direct lipoprotein lipase-mediated mechanisms and indirect mechanisms, such as promoting secretion of triglyceride-rich lipoproteins (TRLs), provoking proinflammatory responses in vascular cells and impairing LPL-independent hepatic clearance of TRL remnants. Encouraging results from clinical trials using antisense oligonucleotide, which selectively inhibits apoC-III, indicate that modulating apoC-III may be a potent therapeutic approach to managing dyslipidemia and cardiovascular disease risk.Peer reviewe
On the ecology of two Rhipidocotyle species (Digenea: Bucephalidae) from two Finnish lakes
No full textThe life-cycles of two Rhipidocotyle species and their ecology at different life-cycle stages, especially the host-parasite relationships in the first intermediate host, were studied during 1987-89 in Lake Saravesi, central Finland, and Lake Kuivasjärvi, northern Finland. At the beginning of the study, bucephalid digeneans were found in Rutilus rutilus and adult bucephalids of the genus Rhipidocotyle were found in predatory fishes from Lake Saravesi. However, two bucephalid species, the cercariae of the first having long, filamentous furcae (Type A) and the second having short, stout furcae (Type B), were detected in Anodonta anatina from the lake. Experimental life-cycle studies on the parasites had to be established, in which uninfected roach were infested with a known type of cercaria and the roach were fed to uninfected Esox lucius or Perea fluviatilis. Type B was revealed to be R. campanula (Dujardin, 1845). Type A also belonged to the genus Rhipidocotyle, being a species new to science and was described under name R. fennica Gibson, Taskinen & Valtonen, 1992. Both species used A. anatina as the first intermediate host and R. rutilus as the second intermediate host. The final hosts of R. fennica and R. campanula were E. lucius and P. fluviatilis, respectively. The metacercariae of R. fennica, which mainly occurred encysted in the skin and fins of R. rutilus, could be distinguished by the more psterior position of the pharynx along the body when compared to R. campanula which, on the other hand, mainly occurred encysted in the gills of R. rutilus. Adult R. fennica could be separated from R. campanula e.g. by its smaller egg size and more posterior position of the anterior margin of the vitelline fields. The prevalences of R. fennica and R. campanula in A. anatina from Lake Saravesi (n=l,157) were 33.2 % and 1.0 %, respectively. Pseudanodonta complanata (n=29), Unio tumidus and U. pictorum (n=65) from Lake Saravesi were not infected. The prevalence of R. campanula in A. anatina from Lake Kuivasjärvi (n=l,486) was 4.7 % and R. fennica did not occur in that lake. A. anatina collected from Lake Saravesi ranged from 1 to 15 years and from 21 to 112 mm. The clam specimens ≤ 3 years or ≤ 51 mm were not infected with R. fennica. The prevalence of R. fennica in A. anatina from Lake Saravesi was higher in the littoral zone, among older, bigger, fast growing and female clams.unknown accessibilityei tietoa saavutettavuudest
On boundedness and compactness of Toeplitz operators in weighted H-infinity-spaces
No full text[EN] We characterize the boundedness and compactness of Toeplitz operators T-a with radial symbols a in weighted H-infinity-spaces H(v)(infinity)on the open unit disc of the complex plane. The weights v are also assumed radial and to satisfy the condition (B) introduced by the second named author. The main technique uses Taylor coefficient multipliers, and the results are first proved for them. We formulate a related sufficient condition for the boundedness and compactness of Toeplitz operators in reflexive weighted Bergman spaces on the disc. We also construct a bounded harmonic symbol f such that T-f is not bounded in H-v(infinity) for any v satisfying mild assumptions. As a corollary, the Bergman projection is never bounded with respect to the corresponding weighted sup-norms. However, we also show that, for normal weights v, all Toeplitz operators with a trigonometric polynomial as the symbol are bounded on H-v(infinity) . (C) 2020 Elsevier Inc. All rights reserved.The research of Bonet was partially supported by the projects MTM2016-76647-P and GV Prometeo/2017/102 (Spain). The research of Taskinen was partially supported by a research grant from the Faculty of Science of the University of Helsinki.Bonet Solves, JA.; Lusky, W.; Taskinen, J. (2020). On boundedness and compactness of Toeplitz operators in weighted H-infinity-spaces. Journal of Functional Analysis. 278(10):1-26. https://doi.org/10.1016/j.jfa.2019.108456S12627810Bonet, J., Lusky, W., & Taskinen, J. (2018). Solid hulls and cores of weighted H ∞ -spaces. Revista Matemática Complutense, 31(3), 781-804. doi:10.1007/s13163-018-0265-6Bonet, J., Lusky, W., & Taskinen, J. (2019). Solid cores and solid hulls of weighted Bergman spaces. Banach Journal of Mathematical Analysis, 13(2), 468-485. doi:10.1215/17358787-2018-0049Constantin, O., & Peláez, J. Á. (2015). Boundedness of the Bergman projection on Lp-spaces with exponential weights. Bulletin des Sciences Mathématiques, 139(3), 245-268. doi:10.1016/j.bulsci.2014.08.012Dostanić, M. R. (2004). UNBOUNDEDNESS OF THE BERGMAN PROJECTIONS ON SPACES WITH EXPONENTIAL WEIGHTS. Proceedings of the Edinburgh Mathematical Society, 47(1), 111-117. doi:10.1017/s0013091501000190Engliš, M. (2008). Toeplitz operators and weighted Bergman kernels. Journal of Functional Analysis, 255(6), 1419-1457. doi:10.1016/j.jfa.2008.06.026Grudsky, S., & Vasilevski, N. (2001). Bergman-Toeplitz operators: Radial component influence. Integral Equations and Operator Theory, 40(1), 16-33. doi:10.1007/bf01202952Harutyunyan, A., & Lusky, W. (2010). On L1-subspaces of holomorphic functions. Studia Mathematica, 198(2), 157-175. doi:10.4064/sm198-2-4Luecking, D. H. (1987). Trace ideal criteria for Toeplitz operators. Journal of Functional Analysis, 73(2), 345-368. doi:10.1016/0022-1236(87)90072-3Luecking, D. H. (2007). Finite rank Toeplitz operators on the Bergman space. Proceedings of the American Mathematical Society, 136(05), 1717-1724. doi:10.1090/s0002-9939-07-09119-8Lusky, W. (1995). On Weighted Spaces of Harmonic and Holomorphic Functions. Journal of the London Mathematical Society, 51(2), 309-320. doi:10.1112/jlms/51.2.309Lusky, W. (2006). On the isomorphism classes of weighted spaces of harmonic and holomorphic functions. Studia Mathematica, 175(1), 19-45. doi:10.4064/sm175-1-2Lusky, W., & Taskinen, J. (2008). Bounded holomorphic projections for exponentially decreasing weights. Journal of Function Spaces and Applications, 6(1), 59-70. doi:10.1155/2008/217160Lusky, W., & Taskinen, J. (2011). Toeplitz operators on Bergman spaces and Hardy multipliers. Studia Mathematica, 204(2), 137-154. doi:10.4064/sm204-2-3Mannersalo, P. (2016). Toeplitz operators with locally integrable symbols on Bergman spaces of bounded simply connected domains. Complex Variables and Elliptic Equations, 61(6), 854-874. doi:10.1080/17476933.2015.1120293STROETHOFF, K. (1998). Compact Toeplitz operators on Bergman spaces. Mathematical Proceedings of the Cambridge Philosophical Society, 124(1), 151-160. doi:10.1017/s0305004197002375Taskinen, J., & Virtanen, J. (2010). Toeplitz operators on Bergman spaces with locally integrable symbols. Revista Matemática Iberoamericana, 693-706. doi:10.4171/rmi/614Zorboska, N. (2003). Toeplitz operators with BMO symbols and the Berezin transform. International Journal of Mathematics and Mathematical Sciences, 2003(46), 2929-2945. doi:10.1155/s016117120321203
On a problem of topologies in infinite dimensional holomorphy
No full textThe authors solve an interesting open problem concerning the equivalence of the compact-open topology τ0 and the Nachbin ported topology τω on spaces of holomorphic functions. (See, for example, the book by S. Dineen [Complex analysis in locally convex spaces, North-Holland, Amsterdam, 1981; MR0640093 (84b:46050)] for background.) Let H(U) denote the space of complex-valued holomorphic functions on an open subset U of a complex Fréchet-Montel space F. Ansemil and S. Ponte [Arch. Math. (Basel) 51 (1988), no. 1, 65–70; MR0954070 (90a:46109)] showed that these two topologies agree on H(U) for balanced U if and only if, for every natural number n, P(nF) is a Montel space. Using this result, they showed that for balanced open subsets U of certain non-Schwartz, Fréchet-Montel spaces, τ0=τω. Earlier, J. Mujica [J. Funct. Anal. 57 (1984), no. 1, 31–48; MR0744918 (86c:46050)] had shown that τ0=τω for Fréchet-Schwartz spaces. It is not hard to see that the two topologies differ if F is not Montel.
The authors' counterexample is the Fréchet-Montel space F of Taskinen [Studia Math. 91 (1988), no. 1, 17–30; MR0957282 (89k:46087)]. The authors observe that the complete symmetric projective tensor product Fs⊗ˆπF contains an isomorphic copy of l1. Consequently, P(2F) cannot be Montel, and the result follows.Depto. de Análisis Matemático y Matemática AplicadaFac. de Ciencias MatemáticasTRUEpu
Unbounded Bergman projections on weighted spaces with respect to exponential weights
No full text[EN] There are recent results concerning the boundedness and also unboundedness of Bergman projections on weighted spaces of the unit disc in special cases of rapidly decreasing weights, i.e. "large" Bergman spaces. The aim of our paper is to show that the cases of boundedness are largely exceptional: in general the Bergman projections are unbounded. In addition we give a new, more functional analytic proof for the known central boundedness case which also enables us to transfer our results to harmonic Bergman spaces.The research of Bonet was partially supported by the project MCIN PID2020-119457GB-I00/AEI/10.13039/501100011033. The research of Taskinen was partially supported by the Vaisala Foundation of the Finnish Academy of Sciences and Letters.Bonet Solves, JA.; Lusky, W.; Taskinen, J. (2021). Unbounded Bergman projections on weighted spaces with respect to exponential weights. Integral Equations and Operator Theory. 93(6):1-21. https://doi.org/10.1007/s00020-021-02680-2S121936Arroussi, H.: Function and operator theory on large Bergman spaces. Ph.D. thesis, Universitat de Barcelona (2016)Bonet, J., Lusky, W., Taskinen, J.: Solid hulls and cores of weighted -spaces. Rev. Mat. Complut. 31, 781–804 (2018)Bonet, J., Lusky, W., Taskinen, J.: Solid cores and solid hulls of weighted Bergman spaces. Banach J. Math. Anal. 13(2), 468–485 (2019)Constantin, O., Pelaéz, J.: Boundedness of the Bergman projection on -spaces with exponential weights. Bull. Sci. Math. 139, 245–268 (2015)Dostanić, M.: Unboundedness of the Bergman projections on spaces with exponential weights. Proc. Edinb. Math. Soc. 47, 111–117 (2004)Dostanić, M.: Integration operators on Bergman spaces with exponential weight. Rev. Mat. Iberoam. 23, 421–436 (2007)Dostanić, M.: Boundedness of the Bergman projections on -spaces with radial weights. Publ. Inst. Math. (Belgr.) 86, 5–20 (2009)Harutyunyan, A., Lusky, W.: On -subspaces of holomorphic functions. Studia Math. 198, 157–175 (2010)He, Z., Lv, X., Schuster, A.: Bergman spaces with exponential weights. J. Funct. Anal. 276, 1402–1429 (2019)Hedenmalm, H., Korenblum, B., Zhu, K.: Theory of Bergman Spaces, Graduate Texts in Mathematics, vol. 199. Springer, New York (2000)Lusky, W.: On the Fourier series of unbounded harmonic functions. J. Lond. Math. Soc. 61(2), 568–580 (2000)Lusky, W.: On the isomorphism classes of weighted spaces of harmonic and holomorphic functions. Studia Math. 175, 19–45 (2006)Lusky, W., Taskinen, J.: Bounded holomorphic projections for exponentially decreasing weights. J. Funct. Spaces Appl. 6(1), 59–70 (2008)Pavlović, M.: On harmonic conjugates with exponential mean growth. Czechoslov. Math. J. 49(4), 733–742 (1999)Pavlović, M., Peláez, J.A.: An equivalence for weighted integrals of an analytic function and its derivative. Math. Nachr. 281(11), 1612–1623 (2008)Peláez, J.A., Rättyä, J.: Bergman projection induced by radial weight. Adv. Math. 391, 107950 (2021)Zeytuncu, Y.E.: -regularity of weighted Bergman projections. Trans. Am. Math. Soc. 365, 2959–2976 (2013)Zhu, K.: Operator Theory in Function Spaces, Mathematical Surveys and Monographs, vol. 138, 2nd edn. American Mathematical Society, Providence (2007
Thermal expansion anomalies of R(Fe, M)(12) (R=Y, Nd; M=Mo and Si)
No full textStructural and thermal-expansion anomaly studies on R(Fe,M)(12) (R=Nd and and Y, M=Mo and Si) compounds were performed by x-ray diffraction. Mo atoms occupy the 8i site. While Si atoms occupy the 8f and 8j sites but not the 8i site. Thermal-expansion anomaly shows only in ab plane in the Mo compounds, while becomes very weak and along with only the c axis in the Si compounds. The anomaly was attributed to the contribution of the interactions of short Fe-Fe distances similar to the previous explanation on other R-Fe intermetallics and that of other strongly positive interactions such as 8j-8j. (c) 2005 American Institute of Physics.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000230168300025&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Physics, AppliedSCI(E)EICPCI-S(ISTP)
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