A review on nonlinear DNA physics

The study and the investigation of structural and dynamical properties of complex systems have attracted considerable interest among scientists in general and physicists and biologists in particular. The present review paper represents a broad overview of the research performed over the nonlinear dynamics of DNA, devoted to some different aspects of DNA physics and including analytical, quantum and computational tools to understand nonlinear DNA physics. We review in detail the semi-discrete approximation within helicoidal Peyrard–Bishop model and show that localized modulated solitary waves, usually called breathers, can emerge and move along the DNA. Since living processes occur at submolecular level, we then discuss a quantum treatment to address the problem of how charge and energy are transported on DNA and how they may play an important role for the functioning of living cells. While this problem has attracted the attention of researchers for a long time, it is still poorly understood how charge and energy transport can occur at distances comparable to the size of macromolecules. Here, we review a theory based on the mechanism of ‘self-trapping’ of electrons due to their interaction with mechanical (thermal) oscillation of the DNA structure. We also describe recent computational models that have been developed to capture nonlinear mechanics of DNA in vitro and in vivo , possibly under topological constraints. Finally, we provide some conjectures on potential future directions for this field.

Quinoa (Chenopodium quinoa Willd) Production in the Andean Region: Challenges and Potentials

Quinoa (Chenopodium quinoa Willd) has functional and nutritional value due to its content of amino acids, antioxidants, vitamins, carbohydrates, starch and oil. It is a crop with a wide geographic distribution in the Andean Region, where the greatest diversity of crop forms, genotypes and wild progenitors is found. It is a short day’s photoperiod plant, with efficient use of water, photosynthesis and stomatal conductance. It prefers loam-sandy to clay loam well-drained soils because it is sensitive to excess moisture. It requires from 10 to 18°C with a thermal oscillation of 5 to 7°C. In Ecuador, quinoa grows between 2500 - 3600 masl; however, in Peru and Bolivia quinoa grows from sea level to 4000 masl. The luminosity of 5 to 7 h day-1 is suitable to meet transpiration and photosynthetic processes. Quinoa is a crop that has all the essential amino acids, suitable mineral elements, vitamins and does not contain gluten. Regarding fertilization, quinoa is highly demanding of N, P, K and Ca. The production volume of quinoa in the Andes is approximate of 180000 t y-1 and uses around 191000 ha, with Peru (the leading world producer) reaching the highest production (105000 t, 69000 ha), followed by Bolivia (75000 t, 121000 ha) and Ecuador (12000 t, 7000 ha). The demand for quinoa has increases in USA (60%) and Europe (90%), but those areas have not the agronomic conditions for quinoa´s growth. This opens an international market opportunity for Andean countries. Nevertheless, quinoa´s production faces several challenges.

Redes Neuronales Artificiales: factores que determinan la cosecha de caña en la industria azucarera.// Artificial Neural Networks: factors that determine the cane harvest in a sugar industry.

La investigación muestra lo importante de las redes neuronales artificiales dentro de la industria azucarera, como una herramienta útil para la predicción del cultivo de la caña de azúcar, tomando como entradas la información climatológica: temperaturas máximas y mínimas, oscilación térmica, precipitaciones, heliofanía, humedad relativa, evaporación y hectáreas de los cultivos sembrados, para obtener una salida: toneladas de caña. Se desarrolló una herramienta de trabajo predictiva con resultados confiables, comparados con métodos tradicionales utilizados, como los aforos de expertos para la cosecha de la caña de azúcar. Se analizó la base de datos histórica de la organización, mediante un software MATLAB, herramienta matemática, que ofrece un entorno de desarrollo integrado (IDE) con lenguaje M de programación propio. La investigación se desarrolló en Compañía Azucarera Valdez S.A. Ubicada en la Ciudad de Milagro-Provincia del Guayas-Ecuador.AbstractThe research shows the importance of artificial neural networks within the sugar industry, as a useful tool for the prediction of the cultivation of sugarcane, taking as input the climatological information: maximum and minimum temperatures, thermal oscillation, rainfall, heliophany, relative humidity, evaporation and hectares of crops planted, to obtain tons of cane as an output. A predictive work tool with reliable results was developed, compared with traditional methods used, such as expert assessment for sugarcane harvesting. The historical database of the organization was analyzed through MATLAB software, a mathematical tool which offers an integrated development environment (IDE) with its own M programming language. The research was developed at Compañía Azucarera Valdez S.A. located in the City of Milagro-Province of Guayas-Ecuador.

Determination of effective specific heat capacity of interior plaster containing phase change materials

A precise technique for determination of effective specific heat capacity of building materials is presented within this paper. The applicability of the technique is demonstrated on a PCM-enhanced plaster, being characterized by a phase change between 15 and 30 °C. The effective specific heat capacity is determined by means of inverse analysis of calorimetric data using computational model of the device. The identified effective specific heat capacity values reached up to 1890 J·kg-1·K-1 when cooled and 1580 J·kg-1·K-1 when heated. Using this quantity in simulation of thermal performance, the PCM-enhanced plaster showed to have a promising potential to be used in buildings’ interiors as a thermal regulator to stabilize inner environment as it contributed to a thermal oscillation decrease by up to 2.5 °C

Methodological Evaluation of Family House with Different Thermo-Physical Parameters of Building Materials

Paper is focused on the assessment of two alternatives of family house from environmental performance. Environmental impact categories such as Global warming potential (GWP), Acidification potential (AP) and Eutrophication potential (EP) expressed as CO2eq, SO2eq and PO43−eq using the LCA assessment method are presented. Alternative solutions of building materials are also compared from phase shift of thermal oscillation. Results show that natural building materials are characterized by lower environmental impacts expressed as equivalent emissions of CO2 (6%), SO2 (24%) and PO43− (44%). The wood fiber board can store nearly 24 times more heat than the mineral wool. The wood fiber boards have a phase shift of thermal oscillation of 7–13 h, while other insulation materials only about 3–4 h.

Effect of oral dietary supplement for chicks subjected to thermal oscillation on performance and intestinal morphometry

The aim of the study was to evaluate the efficacy of a nutritional formulation based on amino acids and vitamins supplemented in the drinking water for chicks in the first week of life subjected to thermal oscillation on performance, organ development and intestinal morphometry from 1 to 21 days. 640-male broiler chicks were distributed in a 2x2 factorial completely randomized design (with or without dietary supplementation and at comfort temperature or thermal oscillation). Chicks subjected to thermal oscillation presented worse performance (p < 0.05) than those under thermal comfort of 1 to 7, 1 to 14 and 1 to 21 days. Nutritional supplementation did not alter the performance (p < 0.05) of the birds, but resulted in a higher body weight (p < 0.05) regardless of the environmental thermal condition. At 7 days, chicks under thermal comfort had better intestinal morphometric parameters (p < 0.05), in relation to birds under thermal oscillation. In conclusion, the temperature oscillations caused negative consequences to the productive performance and the intestinal morphology of chicks for which dietary supplementation was not enough to mitigate the effects of the environmental challenge during the first week of life of the birds.

Optimization of Design of Pitched Roofs According to Phase Shift of Thermal Oscillation

It is important to take into account some more parameters, e.g. heat transfer coefficient, hygienic criterion or globalised energetic criterion, nowadays. It is a time when there is a big emphasize on thermal protection of residential buildings. Therefore an important calculation parameter is spoken more often - temperature loss and phase shift of thermal oscillation. This two parameters are very important especially in case of building envelopes based on lightweight supporting and used insulation materials. A pitched roof in residential building or family house is a typical example. This problem is growing even more, if we are taking adverse ratio of outer surface to volume of the space into account. This paper is showing analysis of such building envelope construction, its designing and influence on optimal values of phase shift of thermal oscillation.