System dynamics modelling in systems biology and applications in pharmacology

El modelado matemático de sistemas biológicos complejos es uno de los temas clave en la Biología de Sistemas y varios métodos computacionales basados ​​en la simulación computarizada han sido aplicados hasta ahora para determinar el comportamiento de los sistemas no lineales. La Dinamica de Sistemas es una metodología de modelado intuitivo basada en el razonamiento cualitativo por el cual un modelo conceptual se puede describir como un conjunto de relaciones de causa y efecto entre las variables de un sistema. A partir de esta estructura, es posible obtener un conjunto de ecuaciones dinámicas que describan cuantitativamente el comportamiento del sistema. Centrándose en los sistemas farmacológicos, el modelado compartimental a menudo se utiliza para resolver un amplio espectro de problemas relacionados con la distribución de materiales en los sistemas vivos en la investigación, el diagnóstico y la terapia en todo el cuerpo, los órganos y los niveles celulares. En este artículo presentamos la metodología de modelado de Dinámica del Sistema y su aplicación al modelado de un modelo compartimental farmacocinético-farmacodinámico del efecto de profundidad anestésica en pacientes sometidos a intervenciones quirúrgicas, derivando un modelo de simulación en el entorno de simulación orientada a objetos OpenModelica. La Dinamica de Sistemas se puede ver como una herramienta educativa poderosa y fácil de usar y en la enseñanza de Biología de Sistemas.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Martín Domínguez Esteban. La labor de un arquitecto español exiliado en Cuba

Martín Domínguez Esteban fue uno de esos arquitectos exiliados tras la Guerra Civil en los que, a la escisión vital y profesio-nal, se sumó el hecho de permanecer eclipsado en muchas de sus obras, al no homologársele el título en Cuba. Y en su caso,el exilio fue doble: primero a Cuba y luego a EEU

Double fermiophobic Higgs boson production at the LHC and LC

We consider the phenomenology of a fermiophobic Higgs boson (h_f) at the Large Hadron Collider (LHC) and a e+e- Linear Collider (LC). At both machines the standard production mechanisms which rely on the coupling h_fVV (V=W,Z) can be very suppressed at large tan beta. In such cases the complementary channels pp to H^\pm h_f, A^0 h_f and e+e- to A^0 h_f offer promising cross-sections. Together with the potentially large branching ratios for H^\pm to h_fW* and A^0 to h_fZ*, these mechanisms would give rise to double h_f production, leading to signatures of gamma gamma gamma gamma, gamma gamma VV and VVVV.Comment: 19 pages, 9 figures, expanded discussion, fig.1 changed slightly, version to appear in Phys.Rev.

Optimising the Analysis Stage in the Internationalisation of Manufacturing Operations

[EN] The internationalisation of the manufacturing operations process includes decision-making about new facility implementation (NFI) and global supplier network development (GSND), whose first step is to analyse the situation of a company and its environment. The purpose of this paper is to investigate the optimal design of a manufacturing production and distribution network for global small-and medium-sized enterprises (SMEs). This research uses a mixed-integer linear programming (MILP) model to support decision-making in the analysis stage of the internationalisation of manufacturing operations for global SMEs. A real-world case study is presented to illustrate the application of the proposed model. Different scenarios were evaluated not only to identify the strengths and limitations of the mathematical programming model, but to also provide support for the next strategic decisions that the examined company has to make in the near future.This work was supported by the Spanish Ministry of Science, Innovation and Universities project entitled `Optimisation of zero-defects production technologies enabling supply chains 4.0 (CADS4.0)' (RTI2018-101344-B-I00).Comer, F.; Mula, J.; Díaz-Madroñero Boluda, FM.; Grillo, H. (2021). Optimising the Analysis Stage in the Internationalisation of Manufacturing Operations. The South African Journal of Industrial Engineering. 32(2):124-132. https://doi.org/10.7166/32-2-2371S12413232

Hydrolysis study of bis-1,2-(triethoxysilyl)ethane silane by NMR

The hydrolysis process of bis-1,2-(triethoxysilyl)ethane (BTSE) was studied in aqueous and methanol solutions at pH 4. Nuclear magnetic resonance (NMR) evaluation of different solutions was carried out for 7 days. Unlike other researches, methanol-rich solutions are proven inadequate to reach a complete hydrolysis process. In water-rich solutions, hydrolysis takes place for 3 days, 85% of the silane molecules being transformed into silanols; this amount continues increasing up to the seventh day of hydrolysis.Authors wish to acknowledge the Ministry of the Environment (through project 136/PC08/3-11.2) for their financial support in this research

Cultura escolar e novos modelos culturais : duas realidades incompatíveis?

este texto apresenta resultados de debates promovido numa rede de discussão pela Internet, com a participação de investigadores de didática da Universidade de Sevilha, Espanha, e professores de escolas públicas e privadas. O tema dos debates esteve centrado na relação entre a escola e as novas opções culturais que permeiam a sociedade. Os autores partem da constatação de que vem aumentando consideravelmente a “brecha” entre a cultura em que estão imersas crianças e jovens e a cultura escolar tradicional para, em seguida, propor formas de superação desse desajuste cultural entre o dentro e o fora da escola

Generalized Envelope-Based Modeling of Single-Phase Grid-Connected Power Converters

In-depth models of single-phase grid-tied power converters facilitate the examination of low-frequency (LF) interactions among loads, distributed energy resources (DERs), and synchronous generators by operators and designers. These interactions are becoming increasingly significant with the growing integration of power electronics into electrical grids. This article extends the envelope modeling (EM) technique to develop LF linear time-invariant (LTI) circuit models for single-phase grid-tied power converters. The models utilize an independent phase signal that aligns with the most appropriate reference frame. This methodology preserves the LF dynamics inherent to the power converter and control system. The practicality of this method is evidenced by constructing a model for a bridgeless totem-pole power factor corrector (PFC), which includes a zero-crossing detector (ZCD) and operates without closed-loop regulation. The outcomes from this model are juxtaposed with those from a switched model and other well-stablished modeling techniques for comparison. Furthermore, a commercially available circuit design featuring current and voltage control loops is simulated, and the results are corroborated with experimental data. These experiments are conducted under disturbances influencing the converter’s performance within its linear operational range