Polynomial matrices, representations, and linear system theory

Frequency domain analogies, polynomial matrices, and linear system

Unimodular Transformations and Canonical Forms for Singular Systems

The relationship between the unimodular matrices relating coprime and column reduced matrix fraction descriptions (MFD) of a nonproper transfer function, and the restricted system equivalence (r.s.e.) transformations relating the corresponding generalised state space realisations is considered. It is shown that the r.s.e and unimodular transformations can be directly obtained from each other by inspection. The r.s.e. transformations leading to the canonical form are derived from the unimodular transformations leading to the echelon canonical form of the composite matrix of the MFD of the system

From Mourning to Monuments: How American Society Memorialized the Dead After 1945

The following four memorials — the World War II Memorial in The Fens in Boston, the Brooklyn War Memorial in Cadman Plaza Park, the Pennsylvania Railroad World War II Memorial in the 30th Street Station, and the East Coast War Memorial in Battery Park — suggest that mid-twentieth century commemorative architecture possessed defining characteristics that differentiated them from monuments of the previous era and from each other. These unique qualities make it difficult to define this architectural period in a unified way because multiple forms of memorials arose in the wake of World War II

On decoupling of linear time delay systems by generalized output feedback

Special Issue on Time delay systemsInternational audienceWe consider the row-by-row decoupling problem for linear delay systems by output feedback. The characterization of the solvability of this problem is given in terms of some easily checkable structural conditions. The main contribution is, in particular, to use generalized output feedback laws which may incorporate derivatives of the delayed new reference

Correlates of genetic monogamy in socially monogamous mammals: insights from Azara's owl monkeys

Understanding the evolution of mating systems, a central topic in evolutionary biology for more than 50 years, requires examining the genetic consequences of mating and the relationships between social systems and mating systems. Among pair-living mammals, where genetic monogamy is extremely rare, the extent of extra-group paternity rates has been associated withmale participation in infant care, strength of the pair bond and length of the breeding season. This study evaluated the relationship between two of those factors and the genetic mating system of socially monogamous mammals, testing predictions that male care and strength of pair bond would be negatively correlated with rates of extra-pair paternity (EPP). Autosomal microsatellite analyses provide evidence for genetic monogamy in a pair-living primate with bi-parental care, the Azara’s owl monkey (Aotus azarae). A phylogenetically corrected generalized least square analysis was used to relate male care and strength of the pair bond to their genetic mating system (i.e. proportions of EPP) in 15 socially monogamous mammalian species. The intensity of male care was correlated with EPP rates in mammals, while strength of pair bond failed to reach statistical significance. Our analyses showthat, once social monogamy has evolved, paternal care, and potentially also close bonds, may facilitate the evolution of genetic monogamy.German Science Foundation (HU 1746/2-1); Wenner-Gren Foundation; L.S.B. Leakey Foundation;National Geographic Society; National Science Foundation (BCS-0621020, 1219368, and 1232349); the University of Pennsylvania Research Foundation; the Zoological Society of San Dieg

High-gain nonlinear observer for simple genetic regulation process

High-gain nonlinear observers occur in the nonlinear automatic control theory and are in standard usage in chemical engineering processes. We apply such a type of analysis in the context of a very simple one-gene regulation circuit. In general, an observer combines an analytical differential-equation-based model with partial measurement of the system in order to estimate the non-measured state variables. We use one of the simplest observers, that of Gauthier et al., which is a copy of the original system plus a correction term which is easy to calculate. For the illustration of this procedure, we employ a biological model, recently adapted from Goodwin's old book by De Jong, in which one plays with the dynamics of the concentrations of the messenger RNA coding for a given protein, the protein itself, and a single metabolite. Using the observer instead of the metabolite, it is possible to rebuild the non-measured concentrations of the mRNA and the proteinComment: 9 pages, one figur

Parameterisation of degenerate solutions of the determinantal assignment problem

The paper is concerned with defining and parametrising the families of all degenerate compensators (feedback, squaring down etc) emerging in a variety of linear control problems. Such compensators indicate the boundaries of the control design, but they also provide the means for linearising the non-linear nature of the Determinantal Assignment Problems, which provide the unifying description for all frequency assignment problems (pole, zero) under static and dynamic compensation schemes. The conditions provide the means for the selection of appropriate degenerate solutions that allow frequency assignability in the corresponding frequencies

Nonlinear software sensor for monitoring genetic regulation processes with noise and modeling errors

Nonlinear control techniques by means of a software sensor that are commonly used in chemical engineering could be also applied to genetic regulation processes. We provide here a realistic formulation of this procedure by introducing an additive white Gaussian noise, which is usually found in experimental data. Besides, we include model errors, meaning that we assume we do not know the nonlinear regulation function of the process. In order to illustrate this procedure, we employ the Goodwin dynamics of the concentrations [B.C. Goodwin, Temporal Oscillations in Cells, (Academic Press, New York, 1963)] in the simple form recently applied to single gene systems and some operon cases [H. De Jong, J. Comp. Biol. 9, 67 (2002)], which involves the dynamics of the mRNA, given protein, and metabolite concentrations. Further, we present results for a three gene case in co-regulated sets of transcription units as they occur in prokaryotes. However, instead of considering their full dynamics, we use only the data of the metabolites and a designed software sensor. We also show, more generally, that it is possible to rebuild the complete set of nonmeasured concentrations despite the uncertainties in the regulation function or, even more, in the case of not knowing the mRNA dynamics. In addition, the rebuilding of concentrations is not affected by the perturbation due to the additive white Gaussian noise and also we managed to filter the noisy output of the biological systemComment: 21 pages, 7 figures; also selected in vjbio of August 2005; this version corrects a misorder in the last three references of the published versio

Geometric and algebraic properties of minimal bases of singular systems

For a general singular system with an associated pencil T(S), a complete classification of the right polynomial vector pairs x(s), u(s)), connected with the N{script}r{T(S)}, rational vector space, is given according to the proper-nonproper property, characterising the relationship of the degrees of those two vectors. An integral part of the classification of right pairs is the development of the notions of canonical and normal minimal bases for N{script}r{T(S)} and N{script}r{R(S)} rational vector spaces, where R(s) is the state restriction pencil of Se[E, A, B]. It is shown that the notions of canonical and normal minimal bases are equivalent; the first notion characterises the pure algebraic aspect of the classification, whereas the second is intimately connected to the real geometry properties and the underlying generation mechanism of the proper and nonproper state vectors x(s). The results describe the algebraic and geometric dimensions of the invariant partitioning of the set of reachability indices of singular systems. The classification of all proper and nonproper polynomial vectors x(s) induces a corresponding classification for the reachability spaces to proper-nonproper and results related to the possible dimensions feedback-spectra assignment properties of them are also given. The classification of minimal bases introduces new feedback invariants for singular systems, based on the real geometry of polynomial minimal bases, and provides an extension of the standard theory for proper systems (Warren, M.E., & Eckenberg, A.E. (1975)

Social Return on the investment of the elimination of the vertical transmission of Chagas, HIV / AIDS, HB and Syphilis: Case of a Municipality of the Province of Buenos Aires

Introducción:se busca cuantificar los retornos de la inversión asociados a una intervención en el sistema público de salud de un municipio de la Provincia de Buenos Aires, Argentina, consistente en el fortalecimiento de la estrategia denominada Eliminación de la Transmisión Maternoinfantil de la Infección por VIH, Sífilis, enfermedad de Chagas Congénita e Infección Perinatal por Hepatitis B (ETMI-PLUS). Metodología: el estudio (cuantitativo) se basa en la metodología de Retorno Social de la Inversión (RSI). Se establecieron definiciones ad-hoc para la medición de los retornos sobre la base de los datos disponibles provenientes de diversas fuentes: información primaria de la Secretaría de Salud del MAB; tasas de transmisión congénita de cada enfermedad notificados al Sistema Nacional de Vigilancia de Salud; presupuestos detallados de los recursos asignados al proyecto por parte de la Fundación Mundo Sano y costos de tratamientos e insumos de nomencladores oficiales. Resultados: por cada peso invertido para reforzar la ETMI-PLUS en el MAB, se obtuvo un retorno de casi 4 pesos, gracias a las mejoras en la eliminación vertical de las cuatro enfermedades y al descenso de las complicaciones cardiacas en las mujeres embarazadas diagnosticadas con chagas y tratadas oportunamente. Conclusiones: estos resultados sugieren la existencia de una relación retorno-inversión favorable, analizada bajo una perspectiva conservadora, ya que, se incluyen exclusivamente los ahorros para el sistema de salud y se excluyen otras dimensiones de los retornos vinculadas con las mejoras en los resultados alcanzados.Introduction: we seek to quantify the returns on investment associated with an intervention in the public health system of a Municipality of the Province of Buenos Aires, Argentina. This intervention consists of strengthening the strategy for the Elimination of Mother-to-Child Transmission of HIV Infection, Syphilis, Congenital Chagas Disease and Perinatal Hepatitis B Infection, a strategy called ETMI-PLUS. Methodology: the study (quantitative) is based on the Social Return on Investment (RSI) methodology. Ad-hoc definitions are established for the measurement of returns based on the information available from various sources: primary information from the Ministry of Health of the MAB; rates of congenital transmission of each disease reported to the National Health Surveillance System; detailed budgets of the resources assigned to the project by Fundación Mundo Sano and costs of treatments and supplies from official nomenclators. Results: for each argentinean peso invested in strengthening the ETMI-PLUS in the MAB, a return of almost 4 pesos would have been obtained thanks to the improvements in the vertical elimination of the 4 diseases and the reduction of cardiac complications in pregnant women. Conclusions: these results suggest the existence of a return / investment relationship favorable to the intervention, analyzed under a conservative analysis since savings for the health system are exclusively included and other dimensions of returns associated with improvements in results are excluded.Fil: Monteverde, Laura Malena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones y Estudios Sobre Cultura y Sociedad. Centro de Investigaciones en Ciencias Económicas | Universidad Nacional de Córdoba. Centro de Investigaciones y Estudios Sobre Cultura y Sociedad. Centro de Investigaciones en Ciencias Económicas; ArgentinaFil: Silvestrini, Constanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Endocrinología Experimental y Aplicada; Argentina. Fundación QUANT; ArgentinaFil: Pereiro, Ana Cristina. Fundación Mundo Sano. Instituto de Neurociencias de Buenos Aires. Área de Investigación Científica; ArgentinaFil: Wolovich, Tamara. Centro de Atencion Primaria de la Salud Numero 10 28 de Diciembre (caps 10) ; Municipalidad de Almirante Brown (buenos Aires);Fil: Ceriotto, Mariana. Centro de Atencion Primaria de la Salud Numero 16 Doctor Rafael Calzada (caps 16) ; Gobierno de la Provincia de Buenos Aires;Fil: Castelli, Juan Manuel. Municipio de Almirante Brown; Argentin