1,781 research outputs found
The interaction between marine and subaerial processes in the evolution of rocky coasts: The example of Castelejo (southwest Portugal)
The rocky coast of Castelejo (the Southwest Alentejano and Costa Vicentina Natural Park) represents an excellent example of the complexity that is connected with the current evolution of this type of coasts. Fieldwork supported by cartographic analysis and by aerial and land photographs enabled us to produce a detailed geomorphological map (scale 1:5 000), where the landforms and processes of this area are indicated. At Castelejo we have a very active dynamic at present, with erosion and accumulation processes, either marine or subaerial, combined with changes in frequency and magnitude. The work carried out over the last three years, together with periodic surveys over the last 15 years, show that there is a cyclic sequence of processes that depends on the wave climate (which controls the presence or absence of sand on the beach) and on the climatic regime, mainly the wind and the intensity and concentration of rain.La costa rocosa de Castelejo (localizada en el parque natural del Sudoeste Alentejano y de la costa Vicentina) es un excelente ejemplo de la complejidad que puede revestir la actual evolución de este tipo de litoral. El trabajo de campo apoyado en análisis cartográfico y en fotografÃas aéreas y terrestres, permite ejecutar un mapa detallado (escala 1:5 000) donde se indican las formas y procesos de esta área. En Castelejo se tiene una dinámica actual muy activa, donde erosión y procesos de acumulación, marina o subaérea, se combinan con cambios de frecuencia y magnitud. El trabajo desarrollado en los últimos tres años, junto con observaciones ocasionales de los últimos quince, muestran la existencia de una secuencia cÃclica de procesos que dependen del régimen de agitación marina (que controla la presencia o ausencia de arena en la playa) y del régimen climático, concretamente del viento y de la intensidad y concentración de la lluvia.Instituto Español de OceanografÃ
Detection and quantification of long chain fatty acids in liquid and solid samples and its relevance to understand anaerobic digestion of lipids
A method for long chain fatty acids (LCFA) extraction, identification and further quantification by gas
chromatography was developed and its application to liquid and solid samples collected from anaerobic
digesters was demonstrated. After validation, the usefulness of this method was demonstrated in a cow
manure digester receiving pulses of an industrial effluent containing high lipid content. From the LCFA
analysis data it was showed that the conversion of oleic acid, the main LCFA fed to the reactor, by the
adapted biomass became faster and more effective along the successive pulses. Conversely, the accumulation
of palmitic acid in the solid phase suggests that degradation of this LCFA, under these conditions, is
less effective.Fundo Social Europeu (FSE)Fundação para a Ciência e a Tecnologia (FC
A method to detect and quantify long chain fatty acids in liquid and solid samples and its relevance to understand anaerobic digestion of lipids
A method for long chain fatty acids (LCFA) extraction, identification and further
quantification by capillary gas chromatography was developed and its application to liquid and
solid samples demonstrated. Linear calibration curves (r² between 0.997 and 1.000) were
constructed for C12 to C18 LCFA, in the range from 25 to 1270 mg/L. All the acids were
quantified in a single run using pentadecanoic acid (C15:0) as internal standard with response
factors ranging from 0.79 to 1.09. Relative standard deviation values lower than 15% and mean
LCFA recoveries above 90% were obtained. After validation, the usefulness of this method was
demonstrated in a cow manure digester receiving pulses of an industrial effluent containing high
lipid content. The knowledge obtained with the application of this method can contribute to a
better understanding of LCFA adsorption and degradation processes that occur during the
anaerobic digestion of lipids
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Saharan dust electrification perceived by a triangle of atmospheric electricity stations in Southern Portugal
Atmospheric Electric Potential Gradient (PG) measurements were carried out in three sites forming a triangular array in Southern Portugal. The campaign was performed during the
summer, characterized by Saharan dust outbreaks; 16th-17th July 2014 dust event is considered. Short time-scale oscillations of the PG at two of the stations and a mid time-scale suppression of the PG in the three stations are found. Results are interpreted as evidencing long-range dust
electrification; attributed to the air-Earth electrical current creating a bipolar charge distribution inside of the dust layer. The relevance of using arrays of sensors, instead of single sited, is highlighted
The Farther the Better: Effects of Multiple Environmental Variables on Reef Fish Assemblages along a Distance Gradient from River Influences
The conservation and management of site-attached assemblages of coastal reefs are particularly challenging because of the tremendous environmental variation that exists at small spatial scales. In this sense, understanding the primary sources of variation in spatial patterns of the biota is fundamental for designing effective conservation policies. We investigated spatial variation in fish assemblages around the windward and leeward sides of coastal islands situated across a gradient of riverine influence (13 km in length). Specifically, relationships between rocky reef fish assemblages and benthic, topographic and physical predictors were assessed. We hypothesized that river induced disturbances may overcome local habitat features in modeling spatial patterns of fish distribution. Fish assemblages varied primarily due to the strong directional gradient of riverine influence (22.6% of the estimated components of variation), followed by topographic complexity (15%), wave exposure (9.9%), and benthic cover (8%). The trophic structure of fish assemblages changed from having a high abundance of invertebrate feeders in macroalgae-dominated reefs close to river mouths to a high proportion of herbivores, planktivores and invertebrate feeder species in reefs with large boulders covered by epilithic algal matrices, as the distance from rivers increased. This gradient led to an increase of 4.5-fold in fish richness and fish trophic group diversity, 11-fold in fish biomass and 10-fold in fish abundance. Our results have implications for the conservation and monitoring of assemblages patchily distributed at small spatial scales. The major role of distance from river influences on fish assemblages rather than benthic cover and topographic complexity suggest that managing land-based activities should be a conservation priority toward reef restoration.Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)Conselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq)Univ Fed Rural Rio de Janeiro, Dept Biol Anim, Lab Ecol Peixes, Campus Seropedica, Seropedica, RJ, BrazilUniv Fed Rural Rio de Janeiro, Dept Ciencias Meio Ambiente, Campus Tres Rios, Seropedica, RJ, BrazilUniv Fed Sao Paulo, Inst Mar, Lab Ecol & Conservacao Marinha, Campus Baixada Santista, Santos, SP, BrazilLaboratório de Ecologia e Conservação Marinha, Instituto do Mar, Universidade Federal de São Paulo, Campus Baixada Santista, Santos, SP, BrazilWeb of Scienc
Proteostasis networks in aging: novel insights from text-mining approaches
Aging is a topic of paramount importance in an increasingly elderly society and has been the focus of extensive research. Protein homeostasis (proteostasis) decline is a hallmark in aging and several age-related diseases, but which specific proteins and mechanisms are involved in proteostasis (de)regulation during the aging process remain largely unknown. Here, we used different text-mining tools complemented with protein–protein interaction data to address this complex topic. Analysis of the integrated protein interaction networks identified novel proteins and pathways associated to proteostasis mechanisms and aging or age-related disorders, indicating that this approach is useful to identify previously unknown links and for retrieving information of potential novel biomarkers or therapeutic targets.info:eu-repo/semantics/acceptedVersio
Reflectance of Polytetrafluoroethylene (PTFE) for Xenon Scintillation Light
Gaseous and liquid xenon particle detectors are being used in a number of
applications including dark matter search and neutrino-less double beta decay
experiments. Polytetrafluoroethylene (PTFE) is often used in these detectors
both as electrical insulator and as a light reflector to improve the efficiency
of detection of scintillation photons. However, xenon emits in the vacuum
ultraviolet wavelength region (175 nm) where the reflecting properties of PTFE
are not sufficiently known.
In this work we report on measurements of PTFE reflectance, including its
angular distribution, for the xenon scintillation light. Various samples of
PTFE, manufactured by different processes (extruded, expanded, skived and
pressed) have been studied. The data were interpreted with a physical model
comprising both specular and diffuse reflections. The reflectance obtained for
these samples ranges from about 47% to 66% for VUV light. Fluoropolymers,
namely ETFE, FEP and PFA were also measured
Electroreductive intramolecular cyclization of bromoalkoxylated derivatives catalyzed by nickel(I) tetramethylcyclam in "green" media
The (1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetra-decane)nickel(I), [Ni(tmc)]+, electrogenerated at glassy carbon cathodes is shown to be an effective catalyst for the intramolecular radical-type cyclisation of bromoalkoxylated derivatives 1 in alcohol and / or alcohol/water mixtures as well as in microemulsions made with cationic and anionic surfactants. The results obtained indicate that the reaction proceeds via cleavage of the carbon–bromine bond to form a radicaltype intermediate that undergoes cyclisation on the unsaturated C-C bond to afford substituted tetrahydrofurans. The reactions are more selective and take place at higher current density than when carried out in conventional aprotic solvents
Flashing LEDs for microalgal production
Flashing lights are next-generation tools to mitigate light attenuation and increase the photosynthetic efficiency of microalgal cultivation systems illuminated by light-emitting diodes (LEDs). Optimal flashing light conditions depend on the reaction kinetics and properties of the linear electron transfer chain, energy dissipation, and storage mechanisms of a phototroph. In particular, extremely short and intense light flashes potentially mitigate light attenuation in photobioreactors without impairing photosynthesis. Intelligently controlling flashing light units and selecting electronic components can maximize light emission and energy efficiency. We discuss the biological, physical, and technical properties of flashing lights for algal production. We combine recent findings about photosynthetic pathways, self-shading in photobioreactors, and developments in solid-state technology towards the biotechnological application of LEDs to microalgal production.Foundation for Science and Technology (FCT, Portugal) [CCMAR/Multi/04326/2013]Nord UniversityNordland County Government (project Bioteknologi en framtidsrettet naering)INTERREG V-A Espana-Portugal project [0055 ALGARED + 5E]Portuguese Foundation for Science and Technology [SFRH/BD/105541/2014, SFRH/BD/115325/2016]info:eu-repo/semantics/publishedVersio
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