On the zeros of a minimal realization

AbstractIn an earlier work, the authors have introduced a coordinate-free, module-theoretic definition of zeros for the transfer function G(s) of a linear multivariable system (A,B,C). The first contribution of this paper is the construction of an explicit k[z]-module isomorphism from that zero module, Z(G), to V∗/R∗, where V∗ is the supremal (A,B)-invariant subspace contained in kerC and R∗ is the supremal (A,B)-controllable subspace contained in kerC, and where (A,B,C) constitutes a minimal realization of G(s). The isomorphism is developed from an exact commutative diagram of k-vector spaces. The second contribution is the introduction of a zero-signal generator and the establishment of a relation between this generator and the classic notion of blocked signal transmissions

Stuttering Min oscillations within E. coli bacteria: A stochastic polymerization model

We have developed a 3D off-lattice stochastic polymerization model to study subcellular oscillation of Min proteins in the bacteria Escherichia coli, and used it to investigate the experimental phenomenon of Min oscillation stuttering. Stuttering was affected by the rate of immediate rebinding of MinE released from depolymerizing filament tips (processivity), protection of depolymerizing filament tips from MinD binding, and fragmentation of MinD filaments due to MinE. Each of processivity, protection, and fragmentation reduces stuttering, speeds oscillations, and reduces MinD filament lengths. Neither processivity or tip-protection were, on their own, sufficient to produce fast stutter-free oscillations. While filament fragmentation could, on its own, lead to fast oscillations with infrequent stuttering; high levels of fragmentation degraded oscillations. The infrequent stuttering observed in standard Min oscillations are consistent with short filaments of MinD, while we expect that mutants that exhibit higher stuttering frequencies will exhibit longer MinD filaments. Increased stuttering rate may be a useful diagnostic to find observable MinD polymerization in experimental conditions.Comment: 21 pages, 7 figures, missing unit for k_f inserte

Report of radio interference test on Fifth Dimension, Inc. multicoder, model no. HDA4M-839, serial no. 7243

Electromagnetic interference and susceptibility testing of multicoder compliance to radio interference requirement

On the zeros and poles of a transfer function

AbstractThe poles and zeros of a linear transfer function can be studied by means of the pole module and the transmission zero module. These algebraic constructions yield finite dimensional vector spaces whose dimensions are the number of poles and the number of multivariable zeros of the transfer function. In addition, these spaces carry the structure of a module over a ring of polynomials, which gives them a dynamical or state space structure. The analogous theory at infinity gives finite dimensional spaces which are modules over the valuation ring of proper rational functions. Following ideas of Wedderburn and Forney, we introduce new finite dimensional vector spaces which measure generic zeros which arise when a transfer function fails to be injective or surjective. A new exact sequence relates the global spaces of zeros, the global spaces of poles, and the new generic zero spaces. This sequence gives a structural result which can be summarized as follows: “The number of zeros of any transfer function is equal to the number of poles (when everything is counted appropriately).” The same result unifies and extends a number of results of geometric control theory by relating global poles and zeros of general (possibly improper) transfer functions to controlled invariant and controllability subspaces (including such spaces at infinity)

Cytotoxic polyfunctionality maturation of cytomegalovirus-pp65-specific CD4 + and CD8 + T-cell responses in older adults positively correlates with response size

Cytomegalovirus (CMV) infection is one of the most common persistent viral infections in humans worldwide and is epidemiologically associated with many adverse health consequences during aging. Previous studies yielded conflicting results regarding whether large, CMV-specific T-cell expansions maintain their function during human aging. In the current study, we examined the in vitro CMV-pp65-reactive T-cell response by comprehensively studying five effector functions (i.e., interleukin-2, tumor necrosis factor-α, interferon-γ, perforin, and CD107a expression) in 76 seropositive individuals aged 70 years or older. Two data-driven, polyfunctionality panels (IL-2-associated and cytotoxicity-associated) derived from effector function co-expression patterns were used to analyze the results. We found that, CMV-pp65-reactive CD8 + and CD4 + T cells contained similar polyfunctional subsets, and the level of polyfunctionality was related to the size of antigen-specific response. In both CD8 + and CD4 + cells, polyfunctional cells with high cytotoxic potential accounted for a larger proportion of the total response as the total response size increased. Notably, a higher serum CMV-IgG level was positively associated with a larger T-cell response size and a higher level of cytotoxic polyfunctionality. These findings indicate that CMV-pp65-specific CD4 + and CD8 + T cell undergo simultaneous cytotoxic polyfunctionality maturation during aging

Rotating Convection in an Anisotropic System

We study the stability of patterns arising in rotating convection in weakly anisotropic systems using a modified Swift-Hohenberg equation. The anisotropy, either an endogenous characteristic of the system or induced by external forcing, can stabilize periodic rolls in the K\"uppers-Lortz chaotic regime. For the particular case of rotating convection with time-modulated rotation where recently, in experiment, chiral patterns have been observed in otherwise K\"uppers-Lortz-unstable regimes, we show how the underlying base-flow breaks the isotropy, thereby affecting the linear growth-rate of convection rolls in such a way as to stabilize spirals and targets. Throughout we compare analytical results to numerical simulations of the Swift-Hohenberg equation

Influenza A virus-derived defective interfering particles for antiviral treatment

Here, we report on genetically engineered, propagation-incompetent influenza A virus (IAV) particles, so-called defective interfering particles (DIPs) that have been suggested as a promising novel antiviral agent. Typically, IAV DIPs harbor a large internal deletion in one of their eight genomic viral RNA (vRNA) segments. Further, DIPs are capable of hijacking cellular and viral resources upon co-infection with fully infectious standard virus (STV), resulting in an antiviral effect. Besides this replication interference, DIP infection also stimulates innate immunity, adding to the antiviral efficacy. So far, DIPs were produced in embryonated chicken eggs. To improve scalability and flexibility of processes as well as to increase product quality, we established a cell culture-based DIP production system [1,2]. This includes the development of a genetically engineered virus-cell propagation system that allows production of DIPs without the need to add infectious STV to complement missing gene functions of DIPs. Specifically, the MDCK suspension cell line generated expresses the PB2 protein [2], encoded by segment 1 (S1) of IAV, which is not expressed by “DI244” - a prototypic, well-characterized DIP harboring a deletion in S1. Using this cell culture-based production process in batch [2,3] and perfusion mode [4] at laboratory scale, we show that we can achieve very high DI244 titers of up to 2.6E+11 DIPs/mL. Infections of mice demonstrated that intranasal administration of the produced DI244 material resulted in no apparent toxic effects and in a full rescue of mice co-treated with an otherwise lethal dose of IAV [2]. Please click Download on the upper right corner to see the full abstract

A cytomegalovirus-based vaccine provides long-lasting protection against lethal Ebola virus challenge after a single dose

This is the author accepted manuscript. The final version is available fromElsevier via the DOI in this record.Ebola virus (Zaire ebolavirus; EBOV) is a highly lethal hemorrhagic disease virus that most recently was responsible for two independent 2014 outbreaks in multiple countries in Western Africa, and the Democratic Republic of the Congo, respectively. Herein, we show that a cytomegalovirus (CMV)-based vaccine provides durable protective immunity from Ebola virus following a single vaccine dose. This study has implications for human vaccination against ebolaviruses, as well as for development of a 'disseminating' vaccine to target these viruses in wild African great apes.We thank Dr U. Koszinowski (Max von Pettenkofer-Institute, Ludwig-Maximilians-University, Germany) for providing the pSMfr3 MCMV BAC, and Dr D. Court (NCI-Frederick, MD) for providing the lambda-based recombination system used to construct the original MCMV/ZEBOV-NPCTL construct. We appreciate K. Marshall (VGTI, OR) and J. Bailey (NIAID, MT) for their organization and coordination of animals used in the study. We also thank the members of Rocky Mountain Veterinary Branch (DIR, NIAID, NIH) for assistance with animal care. Finally, we thank Drs H. Ebihara (DIR, NIAID, NIH), A. Marzi (DIR, NIAID, NIH), P. Barry (University of California at Davis, CA), M. Cranfield (Mountain Gorilla Veterinary Project, Baltimore, MD) for insightful discussions. This study was supported by R21 (AI088442) and the Intramural Research Program of the NIAID, NIH; and University of Plymouth, School of Biomedical and Healthcare Sciences internal funding