124,433 research outputs found
Tuberculous dactylitis - an easily missed diagnosis
No full textThe prevalence of tuberculosis (TB) continues to rise worldwide. Current migration patterns and increased travel to high-prevalence TB countries will result in more frequent presentations of less common forms of TB. Tuberculous dactylitis, a form of tuberculous osteomyelitis, is well recognised in countries with a high prevalence of TB. We provide a systematic review of all published cases of tuberculous dactylitis in children and adolescents and describe a case to illustrate the typical features of the disease. Our review revealed 37 cases of tuberculous dactylitis in children and adolescents, all reported in the last 17 years. Children less than 10 years of age are most frequently affected and the hand is the most commonly affected site. Concurrent pulmonary TB is present in a fifth of cases and systemic symptoms are usually absent. Positive TST and IGRA support the presumptive diagnosis, but cannot be used as rule-out tests. The definitive diagnosis relies on the detection M. tuberculosis by PCR or culture. Treatment should comprise of a standard three to four drug anti-tuberculous regimen. The optimal treatment duration remains unknown. Surgery has a limited role in the treatment in general but may play a supportive role, and curettage of the cavity has been recommended for avascular lesion
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Ritz Theater
No full textRitz Theater located on 700 block of N. Chaparra
The use of positive and negative penalty functions in solving constrained optimization problems and partial differential equations
No full textThe Rayleigh-Ritz Method together with the Penalty Function Method is used to investigate the use of different types of penalty parameters. The use of artificial springs as penalty parameters is a very well established procedure to model constraints in the Rayleigh-Ritz Method, the Finite Element Method and other numerical methods. Historically, large positive values were used to define the stiffness coefficient of artificial springs, until recent publications demonstrated that it is possible to use negative values to define the stiffness coefficients of the springs. Furthermore, recent publications show that constraints can be enforced using positive and negative mass or inertia in vibration problems and in a more generic sense using eigenpenalty parameters which are penalty parameters in the matrix associated with the eigenvalue. Before the commencement of this thesis, solutions using artificial inertia were published only for beams and simple spring-mass systems.
In this thesis the use of all possible types of penalty parameters are investigated in vibration problems of Euler-Bernoulli beams, thin plates and shallow shells and in elastic stability analysis of Euler-Bernoulli beams, including penalty parameters associated with the geometrical stiffness matrix. The study includes the use of penalty parameters for both enforcing support boundary conditions and continuity conditions along structural joints.
This investigation started with the selection of the set of admissible functions that would: (a) allow modelling of beams, plates and shells in completely free boundary conditions; (b) not present any limitation in the number of functions that can be used in the solution. This gives the possibility to converge to the constraint solution and to model any type of boundary conditions.
The procedure proposed in this work combines several advantages: accuracy of the results, relative fast convergence, simplicity of the set of admissible functions and flexibility to define boundary conditions. While there are other procedures that may give better accuracy for specific cases, the proposed method is more widely applicable.
The procedure used in this work also includes a way to check for round-off errors and ill-conditioning in the results; as well as a way to bracket the exact solution with upper and lower-bound results
Matrices with prescribed Ritz values
No full textAbstractOn the way to establishing a commutative analog to the Gelfand–Kirillov theorem in Lie theory, Kostant and Wallach produced a decomposition of M(n) which we will describe in the language of linear algebra. The “Ritz values” of a matrix are the eigenvalues of its leading principal submatrices of order m=1,2,…,n. There is a unique unit upper Hessenberg matrix H with those eigenvalues. For real symmetric matrices with interlacing Ritz values, we extend their analysis to allow eigenvalues at successive levels to be equal. We also decide whether given Ritz values can come from a tridiagonal matrix
Ritz Theatre
No full textThe Ritz opened February 22, 1927 at 3422 N. Illinois Street. It began as a movie, burlesque house then later had rock and jazz music. The seating capacity was 1,400. It closed in the mid 1970s
Human immunodeficiency virus-infected boy with Stevens-Johnson syndrome caused by nevirapine
No full textLe voyage souterrain dans les tragédies gothiques de Richard Cumberland
No full textRitz Régis. Le voyage souterrain dans les tragédies gothiques de Richard Cumberland. In: XVII-XVIII. Bulletin de la société d'études anglo-américaines des XVIIe et XVIIIe siècles. N°8, 1979. pp. 113-125
Free vibrations of conical shells via Ritz method
No full textA formulation is presented for the investigation of the free vibrations of open and closed conical shells. Cylindrical ones are derived as a special case. The approach relies upon an efficient implementation of the Ritz method and allows any set of boundary conditions to be accounted for. In addition, the shells can be stiffened via stringers and/or rings, which are modeled by smearing the properties or by accounting for their discreteness. The resulting models are characterized by relatively few degrees of freedom and reduced computational effort. No meshing is required, so even the modeling phase is conducted quickly. A number of test cases is presented, revealing the accuracy of the proposed strategy and suggesting its use a mean for performing preliminary calculations and assisting the analysis and design process of composite shell structures
Availability and use of molecular microbiological and immunological tests for the diagnosis of tuberculosis in Europe - public dataset
No full textThe original data are accessible as .csv file. This dataset supports the publication Tebruegge M, Ritz N, Koetz K, Noguera-Julian A, Seddon JA, et al. (2014) Availability and Use of Molecular Microbiological and Immunological Tests for the Diagnosis of Tuberculosis in Europe. PLOS ONE 9(6): e99129. https://doi.org/10.1371/journal.pone.0099129</span
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