LA ARQUITECTURA UNA MIRADA DESDE LA CULTURA

Architecture as an artistic manifestation constitutes an essential antecedent for cultural development. This article deals in general aspects of the cultural policy of the country and the theoretical concepts of architecture and cultural development from the assessment and reflection of different authors, allowing to make a relations hip between both concepts, emphasizing how the architecture is put manifest the cultural development of the peoples and the preservation of it for the future.La arquitectura como manifestación artística constituye un antecedente esencial para el desarrollo cultural. El presente artículo aborda en sentido general aspectos relacionados con la política cultural del país y los conceptos teóricos de arquitectura y desarrollo cultural a partir de la valoración y reflexión de diferentes autores, permitiendo formalizar una relación entre ambos conceptos, enfatizando como mediante la arquitectura se pone de manifiesto el desarrollo cultural de los pueblos y la preservación de ella para el futuro

LA ARQUITECTURA UNA MIRADA DESDE LA CULTURA

Architecture as an artistic manifestation constitutes an essential antecedent for cultural development. This article deals in general aspects of the cultural policy of the country and the theoretical concepts of architecture and cultural development from the assessment and reflection of different authors, allowing to make a relations hip between both concepts, emphasizing how the architecture is put manifest the cultural development of the peoples and the preservation of it for the future.La arquitectura como manifestación artística constituye un antecedente esencial para el desarrollo cultural. El presente artículo aborda en sentido general aspectos relacionados con la política cultural del país y los conceptos teóricos de arquitectura y desarrollo cultural a partir de la valoración y reflexión de diferentes autores, permitiendo formalizar una relación entre ambos conceptos, enfatizando como mediante la arquitectura se pone de manifiesto el desarrollo cultural de los pueblos y la preservación de ella para el futuro

pH Dependent Antimicrobial Peptides and Proteins, Their Mechanisms of Action and Potential as Therapeutic Agents

Antimicrobial peptides (AMPs) are potent antibiotics of the innate immune system that have been extensively investigated as a potential solution to the global problem of infectious diseases caused by pathogenic microbes. A group of AMPs that are increasingly being reported are those that utilise pH dependent antimicrobial mechanisms and here, we review research into this area. This review shows that these antimicrobial molecules are produced by a diverse spectrum of creatures, including vertebrates and invertebrates, and are primarily cationic although a number of anionic examples are known. Some of these molecules exhibit high pH optima for their antimicrobial activity but in most cases, these AMPs show activity against microbes that present low pH optima, which reflects the acidic pH generally found at their sites of action, particularly the skin. The modes of action used by these molecules are based on a number of major structure / function relationships, which include metal ion binding, changes to net charge and conformational plasticity, and primarily involve the protonation of histidine, aspartic acid and glutamic acid residues at low pH. The pH dependent activity of pore forming antimicrobial proteins involves mechanisms that generally differ fundamentally to those used by pH dependent AMPs, which can be described by the carpet, toroidal pore and barrel-stave pore models of membrane interaction. A number of pH dependent AMPs and antimicrobial proteins have been developed for medical purposes and have successfully completed clinical trials, including kappacins, LL-37, histatins and lactoferrin, along with a number of their derivatives. Major examples of the therapeutic application of these antimicrobial molecules include wound healing as well as the treatment of multiple cancers and infections due to viruses, bacteria and fungi. In general, these applications involve topical administration, such as the use of mouth washes, cream formulations and hydrogel delivery systems. Nonetheless, many pH dependent AMPs and antimicrobial proteins have yet to be fully characterized and these molecules, as a whole, represent an untapped source of novel biologically active agents that could aid fulfillment of the urgent need for alternatives to conventional antibiotics, helping to avert a return to the pre-antibiotic era

Temporal Dynamics of Preferential Flow to a Subsurface Drain

We conducted a sequential tracer leaching study on a 24.4 by 42.7 m field plot to investigate the temporal behavior of chemical movement to a 1.2-m deep field drain during irrigation and subsequent rainfall events over a 14-d period. The herbicides atrazine [6-chloroN-ethyl-N′-(1-methylethyl)-1,3,5-triazine-2,4-diamine], and alachlor [2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide] along with the conservative tracer Br were applied to a 1-m wide strip, offset 1.5 m laterally from a subsurface drain pipe, immediately before an 11.3-h long, 4.2-mm h−1 irrigation. Three additional conservative tracers, pentafluorobenzoate (PF), o-trifluoromethylbenzoate (TF), and difluorobenzoate (DF) were applied to the strip during the irrigation at 2-h intervals. Breakthrough of Br and the two herbicides occurred within the first 2-h of irrigation, indicating that a fraction of the solute transport was along preferential flow paths. Retardation and attenuation of the herbicides indicated that there was interaction between the chemicals and the soil lining the preferential pathways. The conservative tracers applied during the later stages of irrigation arrived at the subsurface drain much faster than tracers applied earlier. The final tracer, applied 6 h after the start of irrigation (DF), took only 15 min and 1 mm of irrigation water to travel to the subsurface drain. Model simulations using a two-dimensional, convective, and dispersive numerical model without an explicit preferential flow component failed to reproduce Br tracer concentrations in the drain effluent, confirming the importance of preferential flow. This study showed that preferential flow in this soil is not a uniform process during a leaching event