1,578 research outputs found
Importance of long-term cycles for predicting water level dynamics in natural lakes
Lakes are disproportionately important ecosystems for humanity, containing 77% of the liquid surface freshwater on Earth and comprising key contributors to global biodiversity. With an ever-growing human demand for water and increasing climate uncertainty, there is pressing need for improved understanding of the underlying patterns of natural variability of water resources and consideration of their implications for water resource management and conservation. Here we use Bayesian harmonic regression models to characterise water level dynamics and study the influence of cyclic components in confounding estimation of long-term directional trends in water levels in natural Irish lakes. We found that the lakes were characterised by a common and well-defined annual seasonality and several inter-annual and inter-decadal cycles with strong transient behaviour over time. Importantly, failing to account for the longer-term cyclic components produced a significant overall underestimation of the trend effect. Our findings demonstrate the importance of contextualising lake water resource management to the specific physical setting of lakes
El suministro de productos petrolíferos a la República en guerra
Este artículo constituye una aproximación al análisis de la estrategia adoptada por el Gobierno republicano para asegurar durante la guerra civil española el suministro continuo de productos petrolíferos con los que alimentar la maquinaria bélica y el sector de economía civil residual. Se apoya, fundamentalmente, en la documentación depositada en el Archivo General de la Cía. Arrendataria del Monopolio de Petróleos, S. A. (Campsa) al que el autor ha tenido acceso gracias a la colaboración de su dirección y al apoyo del B. de España. El testimonio de testigos directos ha contribuido a colmar una parte de las lagunas documentales encontradas en la investigación
Synthesis of Analogs to A-Type Proanthocyanidin Natural Products with Enhanced Antimicrobial Properties against Foodborne Microorganisms
Developing new types of effective antimicrobial compounds derived from natural products
is of interest for the food industry. Some analogs to A-type proanthocyanidins have shown promising
antimicrobial and antibiofilm activities against foodborne bacteria. We report herein the synthesis
of seven additional analogs with NO2 group at A-ring and their abilities for inhibiting the growth
and the biofilm formation by twenty-one foodborne bacteria. Among them, analog 4 (one OH at
B-ring; two OHs at D-ring) showed the highest antimicrobial activity. The best results with these
new analogs were obtained in terms of their antibiofilm activities: analog 1 (two OHs at B-ring; one
OH at D-ring) inhibited at least 75% of biofilm formation by six strains at all of the concentrations
tested, analog 2 (two OHs at B-ring; two OHs at D-ring; one CH3 at C-ring) also showed antibiofilm
activity on thirteen of the bacteria tested, and analog 5 (one OH at B-ring; one OH at D-ring) was able
to disrupt preformed biofilms in eleven strains. The description of new and more active analogs of
natural compounds and the elucidation of their structure-activity relationships may contribute to the
active development of new food packaging for preventing biofilm formation and lengthening the
food shelf life.Andalusian Consejería de Economía y Conocimiento
(FEDER program 2014–2020: grant number 1380669),Spain, and the Spanish Ministerio de CienciaInnovación y Universidades (grant RTI2018-098560-B-C22,FEDER funds of the
European Union)(Grant RTI2018-098560-B-C22, co-financed by the FEDER funds of the
European UnionCentro de Instrumentación Científico-Técnica
(CICT) of the University of Jaén, Spain
Dynamic obstacles avoidance algorithms for unmanned ground vehicles
En las últimas décadas, los vehículos terrestres no tripulados (UGVs) están siendo cada vez más empleados como robots de servicios. A diferencia de los robots industriales, situados en posiciones fijas y controladas, estos han de trabajar en entornos dinámicos, compartiendo su espacio con otros vehículos y personas. Los UGVs han de ser capaces de desplazarse sin colisionar con ningún obstáculo, de tal manera que puedan asegurar tanto su integridad como la del entorno.
En el estado del arte encontramos algoritmos de navegación autónoma diseñados para UGVs que son capaces de planificar rutas de forma segura con objetos estáticos y trabajando en entornos parcialmente controlados. Sin embargo, cuando estos entornos son dinámicos, se planifican rutas más peligrosas y que a menudo requieren de un mayor consumo de energía y recursos, e incluso pueden llegar a bloquear el UGV en un mínimo local.
En esta tesis, la adaptación de algunos algoritmos disponibles en el estado del arte para trabajar en entornos dinámicos han sido planteados. Estos algoritmos incluyen información temporal tales como los basados en arcos de curvatura (PCVM y DCVM) y los basados en ventanas dinámicas (DW4DO y DW4DOT). Además, se ha propuesto un planificador global basado en Lattice State Planner (DLP) que puede resolver situaciones donde los evitadores de obstáculos reactivos no funcionan.
Estos algoritmos han sido validados tanto en simulación como en entornos reales, utilizando distintas plataformas robóticas, entre las que se incluye un robot asistente (RoboShop) diseñado y construido en el marco de esta tesis
A comprehensive eco-efficiency analysis of wastewater treatment plants: estimation of optimal operational costs and greenhouse gas emissions.
Producción CientíficaThe transition to a neutral carbon and sustainable urban water cycle requires improving eco-efficiency in wastewater treatment processes. To support decision-making based on eco-efficiency evaluations, reliable estimations are fundamental. In this study, the eco-efficiency of a sample of 109 WWTPs was evaluated using efficiency analysis tree method. It combines machine learning and linear programming techniques and therefore, overcomes overfitting limitations of non-parametric methods used by past research on this topic. Results from the case study revealed that optimal costs and greenhouse gas emissions depend on the quantity of organic matter and suspended solids removed from wastewater. The estimated average eco-efficiency is 0.373 which involves that the assessed WWTPs could save 0.32 €/m3 and 0.11 kg of CO2 equivalent/m3. Moreover, only 4 out of 109 WWTPs are identified as eco-efficient which implies that the majority of the evaluated facilities can achieve substantial savings in operational costs and greenhouse gas emissions.Junta de Castilla y León - UE-FEDER (CL-EI-2021-07
Bicentenarios : una construcción de pluralidades
Los bicentenarios de las naciones latinoamericanas están ya muy próximos. Bolivia y Ecuador lo celebrarán\neste mismo año; Argentina, Chile, Colombia, México y Venezuela en 2010 y Paraguay en 2011. A las\ncomisiones nacionales creadas en los distintos países para organizar los festejos se suman organismos\nprovinciales, municipales y grupos de la sociedad civil. A la vez, se proponen programas conjuntos de\nasociaciones latinoamericanas regionales o subregionales
Semiempirical Modeling of Reset Transitions in Unipolar Resistive-Switching based Memristors
We have measured the transition process from the high to low resistivity states, i.e., the reset process of resistive switching based memristors based on Ni/HfO2/Si-n+ structures, and have also developed an analytical model for their electrical characteristics. When the characteristic curves are plotted in the current-voltage (I-V) domain a high variability is observed. In spite of that, when the same curves are plotted in the charge-flux domain (Q-phi), they can be described by a simple model containing only three parameters: the charge (Qrst) and the flux (rst) at the reset point, and an exponent, n, relating the charge and the flux before the reset transition. The three parameters can be easily extracted from the Q-phi plots. There is a strong correlation between these three parameters, the origin of which is still under study
Intestinal microbiota modulation at the strain level by the olive oil polyphenols in the diet
Introduction: Previously we have reported a r16S gene next generation
sequencing study on the effect of high fat diets in the intestinal microbiota using a
murine model. However, many important microbial traits occur at strain level and,
in order to detect these population changes, culture-dependent approaches need
to be applied. With this goal, we decided to study a very well-known commensal
genus, Enterococcus, and therefore, intestinal enterococci methodically isolated
during the above-mentioned experiment were analyzed.
Materials and methods: A collection of 75 distinct enterococcal strains isolated
from feces of mice fed a standard diet or high-fat diets enriched with butter,
refined olive oil, or extra virgin olive oil and after 0, 6 or 12 weeks of diet, were
genetically and phenotypically characterized in search of virulence factors,
biogenic amine production and antibiotic resistance. All strains were tested for
the susceptibility in vitro to two virgin olive oil polyphenols, oleuropein (the bitter
principle of olives) and hydroxytyrosol (derived from oleuropein by enzymatic
hydrolysis and responsible for the high stability of olive oil).
Results: No drastic polyphenol effect was found except at high concentrations.
However, when carrying out a comparative statistical study in the 75 strains of
the collection according to the different diets, we have detected significant
differences between the strains isolated from mice fed with a diet enriched with
virgin olive oil and the rest of the diets. EVOO strains also presented less resistance
to antibiotics and a more beneficial profile overall.
Discussion: These results support the prebiotic role of polyphenols, showing how
they are able to modulate the set of strains that comprises a genus in the gut,
allowing them to adapt to a changing environment in the host’s intestine and
possibly exerting effects on its physiologyUniversity of Jaéngrant number PP2015/08/08 (to MM-C and IP)Junta de Andalucía, grant PI Excelencia_2010 AGR 6340 (to MM-C
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