51,487 research outputs found
JACOBSON RADICAL ALGEBRAS WITH QUADRATIC GROWTH
No full textWe show that over every countable algebraically closed field K there exists a finitely generated K-algebra that is Jacobson radical, infinite-dimensional, generated by two elements, graded and has quadratic growth. We also propose a way of constructing examples of algebras with quadratic growth that satisfy special types of relations.</p
Proper Ferroelectricity in the Dion?Jacobson Material CsBi2Ti2NbO10: Experiment and Theory
No full textA diverse range of materials and properties are exhibited by layered perovskites. We report on the synthesis, characterization, and computational investigation of a new ferroelectric?CsBi2Ti2NbO10, an n = 3 member of the Dion?Jacobson (DJ) family. Structural studies using variable temperature neutron powder diffraction indicate that a combination of octahedral rotations and polar displacements result in the polar structure. Density functional theory calculations reveal that the wider perovskite blocks in CsBi2Ti2NbO0 stabilize proper ferroelectricity, in contrast to the hybrid-improper ferroelectricity reported for all other DJ phases. Our results raise the possibility of a new class of proper ferroelectric materials analogous to the well-known Aurivillius phases
Longitarsus tmetopterus Jacobson
No full text<i>Longitarsus tmetopterus</i> Jacobson <p>(Figs. 14, 54–66)</p> <p> <i>Longitarsus tmetopterus</i> Jacobson, 1893: 246 (Type locality: Kazakhstan, Jany­Kurgan: Fluss San­</p> <p>sar. Lectotype Ψ ZMAS, designated here).</p> <p> <i>L. zeravshanicus</i> Palij, 1970:13 (Type locality: Tadzhikistan, Leninabad (1.IV.1955, ♂). Type mate­</p> <p>rial lost). Lopatin, 1977: 220 (synonymy).</p> <p> <i>L. nurataicus</i> Palij, 1970:13 (Type locality: Kzakhstan, Nuratau. Lectotype ♂ USNM, designated</p> <p>here). Lopatin, 1977: 220 (synonymy).</p> <p> Comments: <i>Longitarsus tmetopterus</i> was described from male and female collected near the town of Janykurgan, west of Karatau mountain ridge on 29.III.1892 by D. Glasunov. A single female with the following labels was found in the collection of Zoological Institute (ZMAS): 1) Turkestan, Sansar, Glasunov, 1892; 2) <i>L. tmetopterus</i> typ. Jac. G. Jacobson det.; 3) k. G. Jacobsona. This specimen is designated here as a lectotype in order to have a unique bearer of this name and the standard for its application. A lectotype label is added: Lectotype <i>Longitarsus tmetopterus</i> Jacobson, des. A. Konstantinov 2005. The second specimen mentioned in the original description was not found. In addition, 5 females collected by K. Anger, on 21.III.1900 at Kalanmor, Zakaspiiskoi oblasti, and identified as <i>L. tmetopterus</i> by G. Jacobson are present in Lopatin collection and ZMAS.</p> <p> Proposing <i>L. nurataicus,</i> Palij (1970) did not designate the holotype and depository of his collection is unknown. It is highly possible that it was lost. For <i>L. zeravshanicus</i>, the holotype was indicated. In addition to the locality of the holotype, Palij (1970) sites the following locations: 1) env. of Samarkand (Bulungur), 31.I.1963 (Ψɗ), 6.III.1963 (2 Ψ), 27.III. 1963 (Ψɗ); 2) env. of Nura­Tau, Karakum, 11.V.1945 (3ɗ). Palij (1970) indicated the following locations for <i>L. nurataicus</i>: river valleys of Chu, Syr­Dar’ya, and Zeravshan, piedmont of Turkestanskii, Zeravshanskii, Kirgizskii, Nuratau mountain ridges. He noted that <i>L. nurataicus</i> was collected in hundreds at the last location in April and May of 1965 and 1966. The specimens collected by Palij in 1965 and 1966 near Nuratau, obviously known to him at the time when he described the species, are available in the USNM collection. A male with the following label is designated as the lectotype: khr. Nuratau, 45 km NW. Dzhizaka, 8.IV.1966 (USNM). Five specimens with the same labels are designated as paralectotypes (3 USNM, 2 ZMAS). Four more specimens with the same labels except for 7.IV.1966 are also designated as paralectotypes (3 USNM, 1 ZMAS). Lectotype designation is done in order to have a unique bearer of this name and the standard for its application.</p> <p> Lopatin (1977) synonymized both <i>L. nurataicus</i> and <i>L. zeravshanicus</i> with <i>L. tmetopterus</i>. The female genitalia of the lectotypes of <i>L. tmetopterus</i> (Figs. 64–66) and <i>L. nurataicus</i> (Figs. 60–63) are nearly identical which leaves no doubt in their synonymy. Also type localities of both species are part of the vast territory of Karakum ­ Kyzylkum deserts. As for <i>L. zeravshanicus</i>, there are no specimens that can be unambiguously attributed to this name. Specimens identified as topotypes of <i>L. zeravshanicus</i> in the Lopatin collection originate from Nuratau, and most likely are <i>L. nurataicus</i> (sensu Palij). The holotype of <i>L. zeravshanicus</i> was collected near Leninabad (northern Tadzhikistan) along the valley of Syr­Dar’ya river, not isolated from the main range of <i>L. tmetopterus</i>.</p> <p> The female genitalia of the lectotype of <i>L. tmetopterus</i> and specimens determined by Jacobson as <i>L. tmetopterus</i> (Anger collecting) (Figs. 54–59) exhibit some relatively minor differences in the shape of the vaginal palpi and spermathecal pump, but they are not significant enough to warrant recognition of separate species.</p>Published as part of <i>Konstantinov, Alexander S., 2005, New species of Middle Asian Longitarsus Latreille with discussion of their subgeneric placement (Coleoptera: Chrysomelidae), pp. 19-42 in Zootaxa 1056</i> on pages 30-31, DOI: <a href="http://zenodo.org/record/170096">10.5281/zenodo.170096</a>
The Jacobson topology of Prim* L¹(G) for exponential Lie groups
No full textUngermann O. The Jacobson topology of Prim* L¹(G) for exponential Lie groups. Bielefeld (Germany): Bielefeld University; 2007
The L-p-to-L-q boundedness of commutators with applications to the Jacobian operator
No full textSupplying the missing necessary conditions, we complete the characterisation of the L-p -> L-q boundedness of commutators [b, T] of pointwise multiplication and Calderon-Zygmund operators, for arbitrary pairs of 1 q, our results are new even for special classical operators with smooth kernels. As an application, we show that every f is an element of L-p(R-d) can be represented as a convergent series of normalised Jacobians J(u) = det del uof u is an element of (over dot(W))(1,dp)(R-d)(d). This extends, from p = 1 to p > 1, a result of Coifman, Lions, Meyer and Semmes about J:. (over dot(W))(1,d)(R-d)(d) -> H-1(R-d), and supports a conjecture of Iwaniec about the solvability of the equation Ju = f is an element of L-p(R-d). (C) 2021 The Author(s). Published by Elsevier Masson SAS.Peer reviewe
Modern Interpretation of Vomeronasal Organs` Research in Works of F. Ruysch’s, L. L. Jacobson, R. A. Kolliker
No full textУ статті з’ясовано історію дослідження та відкриття вомероназального органа. В роботі проаналізовано праці Ф. Рейша, С. Т. фон Зоммерінга, Л. Л. Якобсона, Л. Гратіолета, Е. Дьорсі, Р. А. Кьолікера. Найбільш точно морфологію структури описав Р. А. Кьолікер. In the given report we to find out history of research and opening of vomeronasal organ. In research there are the analysed labours: F. Ruysch’s, S. T. von Sommering’s, L. L. Jacobson L. P. Gratiolet, R. A. Kolliker
Clinical efficacy of bronchodilators in equine asthma: Looking for minimal important difference
No full textBackground Airway obstruction is the main trait of severe equine asthma that affects respiratory function and elicits detrimental effects on clinical presentation. Only few and underpowered clinical studies have investigated the impact of improvement in lung function induced by bronchodilators on the clinical signs of asthma-affected horses. Objectives To identify the minimal important difference (MID) in lung function elicited by bronchodilator leading to a meaningful improvement in clinical signs. Study design Pairwise meta-analysis and meta-regression analysis Methods Literature searches were performed for studies that investigated the effect of bronchodilator therapy on lung function and clinical condition of asthmatic horses. The relationship between the change in lung function variables and clinical score was analysed via random-effect meta-regression. One-point change of the Improved clinically Detectable Equine Asthma Scoring System (IDEASS) score was used to identify the MID. Results A significant (P<0.05) relationship was found between the changes in IDEASS score and maximum change in transpulmonary pressure (Delta Ppl(max)) or pulmonary resistance (R-L). Since only the model resulting for R-L passed through the origin (Y-intercept when X = 0: -0.31, 95% CI -0.75 to 0.14), this variable was used to identify the MID correlated with a meaningful improvement in clinical signs. The resulting MID value was a change in R-L of 0.63 cm H2O/L/s (95% CI 0.33-0.94), representing the slope of meta-regression model (high quality of evidence). Main limitations No long-term studies investigated the effect of bronchodilator agents on both lung function and clinical signs in asthmatic horses. Conclusions In conclusion, bronchodilator pharmacotherapy in equine asthma elicits clinically meaningful effect when R-L increases >= 1 cm H2O/L/s, a value indicating the MID. Assessing the MID based on change in R-L may improve the quality of evidence and the scientific impact of future clinical trials as it extends beyond the simple, and limiting, evaluation of statistical significance
De Maiestate / Praeside M. Jacobo Thomasio, Moralis Philosoph. P. P., publice disputabit Johannes Dunte, R. L. Author & Respon: ad diem 9. Septembr. H L. Q. C.
No full textDE MAIESTATE / PRAESIDE M. JACOBO THOMASIO, MORALIS PHILOSOPH. P. P., PUBLICE DISPUTABIT JOHANNES DUNTE, R. L. AUTHOR & RESPON: AD DIEM 9. SEPTEMBR. H L. Q. C.
De Maiestate / Praeside M. Jacobo Thomasio, Moralis Philosoph. P. P., publice disputabit Johannes Dunte, R. L. Author & Respon: ad diem 9. Septembr. H L. Q. C. (1)
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On the Jacobson radical of strongly group graded rings
No full textsummary:For any non-torsion group with identity , we construct a strongly -graded ring such that the Jacobson radical is locally nilpotent, but is not locally nilpotent. This answers a question posed by Puczy{\l}owski
Size-dependent prey availability affects diet and performance of predatory fish at sea: A case study of Atlantic salmon
No full textIdentifying factors determining the performance of individuals is an essential part of resolving what drives population dynamics. For species undergoing ontogenetic shifts in resource and habitat use, this entails assessing individual performance in all habitats used. Whereas survival and growth of anadromous Atlantic salmon, Salmo salar L., in its juvenile, river habitat are known to depend on size-dependent foraging and food availability, individual performance of salmon in the growth habitat out at sea is commonly explained only by abiotic factors. Still, individuals undergo this habitat shift to grow large, suggesting performance should be food-dependent also in the growth habitat. Because fish communities are highly size-structured, the link between predators and their prey may depend on their respective body sizes. Here, we study whether the performance of Baltic Sea salmon in its growth habitat is food- and size-dependent, by combining extensive diet and body size data of Baltic salmon with spatially resolved monitoring data on abundance and size distribution of their main prey, herring, Clupea harengus L., and sprat, Sprattus sprattus L. We found that both the species and size composition of prey in the diet varied with salmon body size. By accounting for this size-dependent predation and the spatially varying size distribution of prey species, we could explain the variation in salmon diet composition among salmon individuals in different Baltic Sea basins and of different length. The proportion of sprat in diet of salmon was better explained by size-specific prey availability (SSP) than total prey biomass, especially for small salmon. Further, salmon body condition increased with SSP, whereas total prey biomass could not explain variation in the condition of salmon. These findings demonstrate that food- and size-dependent processes indeed can influence the performance of anadromous fish also in large marine systems. Thus, we argue that consideration of these processes, stretching across habitats, is important for understanding performance and dynamics of predatory fish in open aquatic systems, as well as for successful management of species such as Atlantic salmon
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