Hydroxylation and translational adaptation to stress: some answers lie beyond the STOP codon.

Regulation of protein synthesis contributes to maintenance of homeostasis and adaptation to environmental changes. mRNA translation is controlled at various levels including initiation, elongation and termination, through post-transcriptional/translational modifications of components of the protein synthesis machinery. Recently, protein and RNA hydroxylation have emerged as important enzymatic modifications of tRNAs, elongation and termination factors, as well as ribosomal proteins. These modifications enable a correct STOP codon recognition, ensuring translational fidelity. Recent studies are starting to show that STOP codon read-through is related to the ability of the cell to cope with different types of stress, such as oxidative and chemical insults, while correlations between defects in hydroxylation of protein synthesis components and STOP codon read-through are beginning to emerge. In this review we will discuss our current knowledge of protein synthesis regulation through hydroxylation of components of the translation machinery, with special focus on STOP codon recognition. We speculate on the possibility that programmed STOP codon read-through, modulated by hydroxylation of components of the protein synthesis machinery, is part of a concerted cellular response to stress.

A natural experiment reveals the impact of hydroelectric dams on the estuaries of tropical rivers.

We tested how sediment trapping by hydroelectric dams affects tropical estuaries by comparing two dammed and two undammed rivers on Mexico's Pacific coast. We found that dams demonstrably affected the stability and productivity of the estuaries. The two rivers dammed for hydroelectricity had a rapid coastal recession (between 7.9 and 21.5 ha year-1) in what should otherwise be an accretional coastline. The economic consequences of this dam-induced coastal erosion include loss of habitat for fisheries, loss of coastal protection, release of carbon sequestered in coastal sediments, loss of biodiversity, and the decline of estuarine livelihoods. We estimate that the cost of the environmental damages a dam can cause in the lower part of basin almost doubles the purported benefits of emission reductions from hydroelectric generation.

Evolution of the vibrational behavior of a guitar soundboard along successive construction phases by means of the modal analysis technique

The crucial piece of a craft guitar is the soundboard since it determines the quality of the sound given by the instrument. From the initial phase (the gross plate with no hole) until the last construction phase (the plate with the full structure) several stages are followed to modify the dynamic behavior of the structure and hence the acoustic response of the final guitar. The aim of this work is to analyze the effect of each modification on the vibrational response of the plate. With this in mind, an experimental modal analysis of all the construction phases has been performed in the low frequency range under free conditions. The response of the plate in each stage is defined by vibration patterns, resonance frequencies, quality factors, and admittance curves.

[Oesophageal leiomyoma: VATS (video-assisted thoracic surgery) resection]. / Leiomioma esofágico: resección por videotoracoscopia. A propósito de un caso.

Leiomyomas are the most common benign tumours of the oesophagus. The most frequent symptoms are dysphagia and epigastric pain, although 50% of patients remain asymptomatic and the tumour is sometimes discovered incidentally. We report a case of oesophageal leiomyoma with emphasis on the operative management by VATS. Traditionally, operative management by transthoracic enucleation is the procedure of choice. In this study we present our experience using a minimally invasive approach.

Leiomioma esofágico: resección por videotoracoscopia. A propósito de un caso / Oesophageal leiomyoma: VATS (Video-assisted Thoracic Surgery) resection. A case report

Los leiomiomas son los tumores benignos más frecuentes del esófago. Los síntomas más frecuentes son la disfagia y el dolor epigástrico, aunque un 50% de los pacientes permanecen asintomáticos y el tumor a veces se descubre por casualidad. Se presenta un caso de leiomioma esofágico con énfasis en el procedimiento quirúrgico por videotoracoscopia. Tradicionalmente, el tratamiento de elección es la enucleación transtorácica. En este estudio presentamos nuestra experiencia con un abordaje mínimamente invasivo(AU)

Leiomyomas are the most common benign tumours of the oesophagus. The most frequent symptoms are dysphagia and epigastric pain, although 50% of patients remain asymptomatic and the tumour is sometimes discovered incidentally. We report a case of oesophageal leiomyoma with emphasis on the operative management by VATS. Traditionally, operative management by transthoracic enucleation is the procedure of choice. In this study we present our experience using a minimally invasive approach(AU)

Coupled modes of the resonance box of the guitar.

Vibrations of the resonance box of the guitar have been studied by means of the modal analysis technique and the finite-element method. An expert craftsman constructed the guitar box with all the structures, internal and external, characteristic of a real instrument for the experimental measurements. The boundary conditions were chosen in order to clarify the soundboard-back interaction only via the internal air coupling. The numerical model allows one to study the influence of each component on the whole box, and the contribution of the modes of the components (wooden box and its parts, and air), to the coupled modes by calculating their participation factors. The coupled modes of the guitar box are discussed taking into account both the finite-element and modal analysis results.