Biotechnological production of taxanes: a molecular approach

Podeu consultar el llibre complet a: http://hdl.handle.net/2445/46988Plant cell cultures constitute a promise for the production of a high number of phytochemicals, although the majority of bioprocesses that have been developed so far have not resulted commercially successful. An overview indicates that most of the research carried out until now is of the empirical type. For this reason, there is a need for a rational approach to the molecular and cellular basis of metabolic pathways and their regulation in order to stimulate future advances. The empirical investigations are based on the optimization of the culture system, exclusively considering input factors such as the selection of cellular lines, type and parameters of culture, bioreactor design and elicitor addition, and output factors such as cellular growth, the uptake system of nutrients, production and yield. In a rational approach towards the elucidation of taxol and related taxane production, our group has studied the relationship between the taxane profile and production and the expression of genes codifying for enzymes that participate in early, intermediate and late steps of their biosynthesis in elicited Taxus spp cell cultures. Our results show that elicitors induce a dramatic reprogramming of gene expression in Taxus cell cultures, which likely accounts for the enhanced production of taxol and related taxanes and we have also determined some genes that control the main flux limiting steps. The application of metabolic engineering techniques for the production of taxol and taxanes of interest is also discussed

CVARN - Rock art virtual corpus of north-western Portugal. A multimedia tool to investigate and describe post-palaeolithic rock art

The purpose of this paper is the dissemination of the Rock Art Virtual Corpus of the Northwest of Portugal (CVARN), a database dedicated to the theme of Post- Palaeolithic rock art in the Northwest of Portugal, which has been available online since the end of September 2014. This software tool is being built and developed under the ENARDAS project, a scientific project financed by the Thematic Factors of Competitiveness Operational Programme and by the European Regional Development Fund, and has been on-going since 2011, but is now open to the entire scientific community. Apart from being a first compilation of different “styles” of rock arts that occur between the western façade of Iberia, between the basins of the Minho and Vouga rivers, it will have both social and scientific functions. In social terms, the results obtained may contribute to regional development, especially regarding development from the perspective of tourism. In scientific terms, it will allow us to promote scientific research in this field of knowledge and to enable scientifically validated arguments for the integration of rock art sites into tourism evaluation projects.info:eu-repo/semantics/acceptedVersio

The Effect of the Launch of Bitcoin Futures on the Cryptocurrency Market: An Economic Efficiency Approach

We analyze the economic efficiency of the cryptocurrency market after the launch of Bitcoin futures by means of the Data Envelopment Analysis and Malmquist Indexes. Our results show that the introduction of Bitcoin futures did not affect the economic efficiency of the cryptocurrency market. However, we observe that Bitcoin obtained the highest risk-return trade-off due to its liquidity compared to the rest of cryptocurrencies. Therefore, our paper underlines the support of investors on Bitcoin to the detriment of the rest of cryptocurrencies

Firewood and timber exploitation during the 3rd and 2nd millennia BC in the Western façade of the Iberian Northwest: wooden resources, territories and chaîne opératoire

As sociedades humanas estabelecem toda uma série de estratégias produtivas destinadas a obter os meios materiais necessários para a sua existência, entre elas, o aprovisionamento de lenha e de madeira. Estas estratégias, além de estarem condicionadas pela oferta ambiental, são igualmente resultantes das características culturais e das capacidades técnicas. Os dados arqueobotânicos que se apresentam procedem de vários lugares de habitação do Calcolítico e da Idade do Bronze da fachada ocidental do Noroeste peninsular com cronologias que abarcam o III e parte do II milénios AC (Martin em preparação; Martín et al. no prelo; Figueiral e Bettencourt 2007). Os resultados obtidos permitiram identificar uma exploração diversificada dos recursos lenhosos que combinava a recolha de lenha e de madeira das áreas da floresta climácica com a proveniente das áreas de mato. As formaçãos arbóreas situadas nas margems dos cursos de água também constituíram fonte de aprovisionamento de combustíveis e, provavelmente, de madeira. A caracterização dos recursos usados em cada um dos casos de estudo permitiu-nos, igualmente, colocar hipóteses sobre o território de vivência, de circulação e de exploração de cada comunidade. A análise dendrológica das amostras registando o grau de curvatura dos anéis de crescimento anual, o diâmetro mínimo dos ramos ou troncos consumidos, a presença de tiloses e de depósitos de resina, a presença de madeira de reação, a conservação do floema e ou da casca, a presença ou a ausência de cicatrizes ou de anéis sinuosos, as mudanças no ritmo de crescimento, entre outras características, em inter-relação com determinados contextos arqueológicos (dimensões dos buracos de poste, por exemplo), proporcionaram, também, hipóteses relacionadas com a cadeia técnica-operativa dos recursos florestais. Ou seja, sobre a sucessão de operações realizadas pelas comunidades humanas desde a extração da matéria até à sua utilização final.This research was developed under the projects: A xestión do bosque e do monte dende a Idade do Ferro a época romana no noroeste da península Ibérica: consumo de combustibles e produción de manufacturas en madeira / Forest and scrubland management from Iron Age to roman period in the Northwest of the Iberian peninsula: firewood consumption and wooden manufacture production, IDEPatri-Deseño e desenvolvemento dun modelo de datos para unha IDE arqueolóxica da Idade do Ferro en Galicia /IDEPatri- Design and development of a data model for an archaeological SPI during the Galician Iron Age: (IDEPatri) 09SEC002CT. Xunta de Galicia, Paisagens da Idade do Bronze no ocidente peninsular / Bronze Age Landscapes in the West of Iberian Peninsula - SFRH/BSAB/986/10 e Geoindicators of natural and anthropogenic palaeoenvironmental evolution in the Portuguese NW, during de Holocene – 2010_CGUP/CCT/UM

Removal of Water Binding Proteins from Dentin Increases the Adhesion Strength of Low-Hydrophilicity Dental Resins

Objectives To investigate the role of proteoglycans (PGs) on the physical properties of the dentin matrix and the bond strength of methacrylate resins with varying hydrophilicities. Methods Dentin were obtained from crowns of human molars. Enzymatic removal of PGs followed a standard protocol using 1 mg/mL trypsin (Try) for 24 h. Controls were incubated in ammonium bicarbonate buffer. Removal of PGs was assessed by visualization of glycosaminoglycan chains (GAGs) in dentin under transmission electron microscopy (TEM). The dentin matrix swelling ratio was estimated using fully demineralized dentin. Dentin wettability was assessed on wet, dry and re-wetted dentin surfaces through water contact angle measurements. Microtensile bond strength test (TBS) was performed with experimental adhesives containing 6% HEMA (H6) and 18% HEMA (H18) and a commercial dental adhesive. Data were statistically analyzed using ANOVA and post-hoc tests (α = 0.05). Results The enzymatic removal of PGs was confirmed by the absence and fragmentation of GAGs. There was statistically significant difference between the swelling ratio of Try-treated and control dentin (p \u3c 0.001). Significantly lower contact angle was found for Try-treated on wet and dry dentin (p \u3c 0.002). The contact angle on re-wet dentin was not recovered in Try-treated group (p = 0.9). Removal of PGs significantly improved the TBS of H6 (109% higher, p \u3c 0.001) and H18 (29% higher, p = 0.002) when compared to control. The TBS of commercial adhesive was not affected by trypsin treatment (p = 0.9). Significance Changing the surface energy of dentin by PGs removal improved resin adhesion, likely due to more efficient water displacement, aiding to improved resin infiltration and polymerization

Firewood and timber exploitation during the third and second millennia BC in Northwestern Iberia: wood resources, territories and chaîne opératoire

Human societies established productive strategies in order to obtain the material resources needed for their day‐to‐day life, including firewood and timber. These strategies were determined by the environmental supply, and also by the cultural characteristics and technical capacities of these communities. This paper presents charcoal analysis data from four Chalcolithic and Bronze Age open‐air settlements located in the northwest of the Iberian Peninsula and occupied during the third and second millennia BC. These results contribute to the knowledge of the exploitation of wooden resources, of the territories where these resources were collected, and of the firewood and timber production process. The identified wood taxa point to a diversified exploitation of the territory, where firewood and timber were collected and/or felled in the deciduous woodland, the river banks and scrubland areas. The characteristics of the wood elements used, the degree of growth ring curvature, the minimum diameter of twigs or logs, etc., as well as other data from archaeological contexts, such as the length of the postholes, were all taken into account to establish hypotheses related to the operative chaine of forest resources. The wooden resources consumed in each site allowed us to hypothesize about the territory of each community.As sociedades humanas estabelecem toda uma série de estratégias produtivas destinadas a obter os meios materiais necessários para a sua existência, entre elas, o aprovisionamento de lenha e de madeira. Estas estratégias, além de estarem condicionadas pela oferta ambiental, são igualmente resultantes das caraterísticas culturais e das capacidades técnicas das comunidades. Os dados arqueobotânicos que se apresentam procedem de vários lugares de habitação do Calcolítico e da Idade do Bronze da fachada ocidental do Noroeste peninsular com cronologias que abarcam o 3º e parte do 2º milénios AC. Os resultados obtidos permitiram identificar uma exploração diversificada dos recursos lenhosos que combinava a recolha de lenha e de madeira da floresta climácica com a proveniente das áreas de mato. As formações arbóreas situadas nas margens dos cursos de água também constituíram fonte de aprovisionamento de combustíveis e, provavelmente, de madeira. A análise dendrológica das amostras registando o grau de curvatura dos anéis de crescimento anual, o diâmetro mínimo dos ramos ou troncos consumidos, entre outras características, em inter‑relação com determinados contextos arqueológicos (dimensões dos buracos de poste, por exemplo), proporcionaram hipóteses relacionadas com a cadeia técnica‑operativa dos recursos florestais. A caracterização dos recursos usados em cada um dos casos de estudo permitiu, igualmente, colocar hipóteses sobre o território de vivência, de circulação e de exploração de cada comunidade.Fundação para a Ciência e Tecnologi

Knee flexion of saxophone players anticipates tonal context of music

Music performance requires high levels of motor control. Professional musicians use body movements not only to accomplish and help technical efficiency, but to shape expressive interpretation. Here, we recorded motion and audio data of twenty participants performing four musical fragments varying in the degree of technical difficulty to analyze how knee flexion is employed by expert saxophone players. Using a computational model of the auditory periphery, we extracted emergent acoustical properties of sound to inference critical cognitive patterns of music processing and relate them to motion data. Results showed that knee flexion is causally linked to tone expectations and correlated to rhythmical density, suggesting that this gesture is associated with expressive and facilitative purposes. Furthermore, when instructed to play immobile, participants tended to microflex (>1 Hz) more frequently compared to when playing expressively, possibly indicating a natural urge to move to the music. These results underline the robustness of body movement in musical performance, providing valuable insights for the understanding of communicative processes, and development of motor learning cues.info:eu-repo/semantics/publishedVersio

Preservation of Quercus robur germplasm by cryostorage of embryogenic cultures derived from mature trees and rapd analysis of genetic stability

This study reports on the cryostorage of embryogenic lines derived from selected mature Quercus robur trees, following application of the PVS2-vitrification based procedure. In seven oak genotypes, embryo recovery levels ranging from 57-92% were obtained when 4-6 mg embryo clumps were precultured for 3 days on 0.3 M sucrose basal medium, treated with PVS2 solution for 60 min at 24ºC, and then immersed in liquid nitrogen (LN). Embryos of six out of seven lines were cryostored for one week and one year and used to evaluate cryopreservation tolerance, germination ability and to assess genetic fidelity by random amplified polymorphic DNA (RAPD) markers. There were no significant differences between the recovery frequencies of samples retrieved from LN after 1 week and 1 year of cryostorage. In five out of six lines, RAPD profiles of cryopreserved somatic embryos and regenerated plantlets were identical to those of the controls. Although polymorphisms were detected in only one cryostored embryo of one genotype, no genetic instability was found in the regenerated plantlets. This methodology appears to be suitable for long-term storage of this valuable germplasm, as the recovered plantlets were found to be genetically stable.Xunta de Galicia project: PGIDIT03RFO40001PR MEC (Spain) project: AGL2006-01387/FORPeer reviewe