Bifurcations and Averages in the Homoclinic Chaos of a Laser with a Saturable Absorber

The dynamical bifurcations of a laser with a saturable absorber were calculated, with the 3-2 level model, as function of the gain parameter. The average power of the laser is shown to have specific behavior at bifurcations. The succession of periodic-chaotic windows, known to occur in the homoclinic chaos, was studied numerically. A critical exponent of 1/2 is found on the tangent bifurcations from chaotic into periodic pulsations.Comment: 6 or 7 pages, 3 figures, publishe

H? filtering of networked systems with time-varying sampling rates

In this paper, the problem of robust filter design for networked systems with time-varying sampling rate is investigated. The design conditions are obtained by using the Lyapunov theory and the Finsler\u27s Lemma. A robust filter, that minimizes an upper bound to the Hinfin performance of the estimation error, is obtained as the solution of an optimization problem. A path-dependent Lyapunov function is used in order to obtain less conservative design conditions. Robust filters based on affine parameter-dependent Lyapunov functions can be obtained as a particular case of the proposed method. Numerical examples illustrate the results

Gravitational non-commutativity and G\"odel-like spacetimes

We derive general conditions under which geodesics of stationary spacetimes resemble trajectories of charged particles in an electromagnetic field. For large curvatures (analogous to strong magnetic fields), the quantum mechanicical states of these particles are confined to gravitational analogs of {\it lowest Landau levels}. Furthermore, there is an effective non-commutativity between their spatial coordinates. We point out that the Som-Raychaudhuri and G\"odel spacetime and its generalisations are precisely of the above type and compute the effective non-commutativities that they induce. We show that the non-commutativity for G\"odel spacetime is identical to that on the fuzzy sphere. Finally, we show how the star product naturally emerges in Som-Raychaudhuri spacetimes.Comment: Two sections added (Relation to the fuzzy sphere, Emergence of the star product). 10 pages, Revtex. To appear in General Relativity and Gravitatio

Chemoenzymatic Synthesis of Luliconazole Mediated by Lipases

A straightforward chemoenzymatic synthesis of luli- conazole has been developed. The key step involved the preparation of the enantiomerically pure beta-halohydrin (1S)-2-chloro- 1-(2,4-dichlorophenyl)-1-ethanol through kinetic resolution of the corresponding racemic acetate. This was achieved by a hydrolytic approach, mediated by the lipase from Thermomyces lanuginosus or Novozym 435\uae. The latter enzyme proved to be a robust biocatalyst for the kinetic resolution, and the halohydrin was obtained with high selectivity (ee > 99%, E > 200) after just 15 min, at 45 \ub0C. It could be reused five times with maintenance of high values of both conversion and enantioselectivity. Subsequently, the (S)-beta-halohydrin was sub- jected to a mesylation reaction; the mesylated derivative re- acted with 1-cyanomethylimidazole in the presence of CS2 to give luliconazole in 43 % yield with >99 % ee

Robust H2 static output feedback to control an autmomotive throttle valve

The paper presents a control strategy for an automotive electronic throttle body, a device largely used into vehicles to increase the efficiency of the combustion engines. The synthesis of the proposed controller is based on a linear matrix inequality (LMI) formulation, which allows us to deal with uncertainties on the measurements of the position of the throttle valve. The LMI approach generates a suboptimal solution for the robust H-2 static output feedback control problem, and the corresponding suboptimal control gain was evaluated in practice to control the valve position of the throttle. The usefulness of the approach has been verified not only by numerical simulations but also by real experiments taken in a laboratory prototype.Postprint (published version

The Heumann-Hotzel model for aging revisited

Since its proposition in 1995, the Heumann-Hotzel model has remained as an obscure model of biological aging. The main arguments used against it were its apparent inability to describe populations with many age intervals and its failure to prevent a population extinction when only deleterious mutations are present. We find that with a simple and minor change in the model these difficulties can be surmounted. Our numerical simulations show a plethora of interesting features: the catastrophic senescence, the Gompertz law and that postponing the reproduction increases the survival probability, as has already been experimentally confirmed for the Drosophila fly.Comment: 11 pages, 5 figures, to be published in Phys. Rev.

VALORES ENERGÉTICOS DO MILHO E DO FARELO DE SOJA DETERMINADOS COM POEDEIRAS NA FASE DE PRODUÇÃO

The aim of the present research work, carried out with laying hens in the stage of production, was the determination of both apparent metabolic energy (AME) and the nitrogen corrected apparent metabolic energy (AMEn) of the corn and soybean meals. A total of 84 Isabrown birds aging 24 weaks were alloted in a randomized blocks design, using two basal reference diets containing 19 and 14% of CP, respectively. For the experiment, two samples of corn replaced in 25% the reference diet containing 19% of CP, and three samples of soy bean meal replaced in 15% the reference ration containing 14% of CP. It hás been found significant differences in regard to the energetic values and the metabolic coefficients of the reference diets added with soybean meal. In conclusion, it hás been found that the EMA and EMAn values, expressed as kcal/kg as dry matter, for the three samples of soybean meal were 2,292 and 2,537; 2,248 and 1,963; 3,252 and 2,847, respectively, and for the samples of corn, 3,157 and 3,061 and 3,477, respectively.O presente trabalho teve pôr objetivo a determinação, em poedeiras em fase de produção, dos valores de energia metabolizável aparente (EMA) e da (EMAn) corrigida pelo balanço de nitrogênio, do milho e do farelo de soja. Foram utilizadas 84 aves Isabrown com 24 semanas de idade, distribuídas em delineamento experimental de blocos ao acaso, utilizando-se duas rações-referência com 19 e a4% de PB (Proteína Bruta), respectivamente. No experimento levado a efeito, duas amostras de milho substituíram em 25% a ração com 19% de PB e três amostras de farelo de soja substituíram em 15% a ração com 14%  de PB, tendo sido verificada diferença significativa nos valores energéticos e nos coeficientes de metabolizabilidade das  e de amostras de farelo de soja estudadas. Em conclusão, verificou-se que os valores de EMA e EMAn para as três amostras de farelo de soja foram de 2.992, 2.537; 2.248 e de 3.157 e 3.061; e 3.590 e 3.477 kcal/kg de matéria seca, respectivamente, e de 3.157 e 3.061; e 3.590 e 3.477 kcal/kg de matéria seca para as duas amostras de milho, respectivamente

Gene-based Interventions for Cancer Immunotherapy

Immunotherapy of cancer has deservedly gained much attention in the past few years and is likely to continue to advance and become a fundamental cancer treatment. While vaccines, chimeric antigen receptor (CAR) T cells and checkpoint blockade have received the lion’s share of the attention, an important direct role for gene transfer as an immunotherapy is emerging. For example, oncolytic viruses induce immunogenic cell death, thus liberating both antigens and the signals that are necessary for the activation of antigen-presenting cells, ensuring stimulation of an adaptive response. In another example, transfer of prodrug converting enzymes, such as the herpes simplex virus-thymidine kinase (HSV-tk) gene or the cytosine deaminase gene, has been shown to promote an immune response, thus functioning as immunotherapies. Alternatively, our own work involves the use of nonreplicating viral vectors for the simultaneous delivery of gene combinations that promote both cell death and an immune response. In fact, our gene transfer approach has been applied as a vaccine, immunotherapy or in situ gene therapy, resulting in immunogenic cell death and the induction of a protective immune response. Here, we highlight the development of these approaches both in terms of technical advances and clinical experience