1,808 research outputs found
Demystifying COVID-19 digital contact tracing: A survey on frameworks and mobile apps
The coronavirus pandemic is a new reality and it severely affects the modus
vivendi of the international community. In this context, governments are
rushing to devise or embrace novel surveillance mechanisms and monitoring
systems to fight the outbreak. The development of digital tracing apps, which
among others are aimed at automatising and globalising the prompt alerting of
individuals at risk in a privacy-preserving manner is a prominent example of
this ongoing effort. Very promptly, a number of digital contact tracing
architectures has been sprouted, followed by relevant app implementations
adopted by governments worldwide. Bluetooth, and specifically its Low Energy
(BLE) power-conserving variant has emerged as the most promising short-range
wireless network technology to implement the contact tracing service. This work
offers the first to our knowledge, full-fledged review of the most concrete
contact tracing architectures proposed so far in a global scale. This endeavour
does not only embrace the diverse types of architectures and systems, namely
centralised, decentralised, or hybrid, but it equally addresses the client
side, i.e., the apps that have been already deployed in Europe by each country.
There is also a full-spectrum adversary model section, which does not only
amalgamate the previous work in the topic, but also brings new insights and
angles to contemplate upon.Comment: 34 pages, 3 figure
Metabolic engineering for improving anthranilate synthesis from glucose in Escherichia coli
© 2009 Balderas-Hernández et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Furfural, 5-HMF, acid-soluble lignin and sugar contents in C. ladanifer and E. arborea lignocellulosic biomass hydrolysates obtained from microwave-assisted treatments in different solvents
Cistus ladanifer L. and Erica arborea L. are the two most representative shrub species from the Iberian Peninsula. With a view to their valorization, their biomass hydrolysate components, obtained from microwave-assisted treatments with choline chloride/urea - HNO3 10%, N,N-dimethylacetamide/NaHCO3 and N,N-dimethylacetamide/CH3OK as solvents, have been measured using a spectrophotometric method. Concentrations of furfural and 5-(hydroxymethyl)furfural (5-HMF) in the filtrate have been determined after reduction with NaBH4. The production of total sugars, reducing sugars and non-reducing sugars has also been assessed. The obtained results support the choice of microwave-assisted choline chloride/urea deep eutectic solvent in acid media as the preferred method (over the polar aprotic solvent-based alternatives) for the extraction of lignin, furfural, 5-HMF and sugars from C. ladanifer and E. arborea biomass, attaining the best production yields for 60¿min exposure times. Another is the case if the aim of the treatments is to recovery sugars from both shrubs for subsequent enzymatic saccharification: the very low 5-HMF contents resulting from the dimetylacetamide systems (especially is association with CH3OK) make them highly advantageous as compared to the traditional method using NaOH
Crystallinity of cellulose microfibers derived from Cistus ladanifer and Erica arborea shrubs
The effectiveness of the use of cellulose fibers as particulates/composite reinforcers involves the assessment of the crystallinity of such fibers. The aim of the present work is to provide information on the degree of crystallinity of the cellulose microfibers obtained from the stems of Cistus ladanifer and Erica arborea shrubs through two different methods, namely an alkaline treatment and a microwave-assisted deep eutectic solvent (DES) method. The crystallinity indexes (CrI) obtained from X-ray powder diffraction patterns indicated that higher CrI were attained for cellulose obtained from the DES treatment. Complementary information on the degree of crystallinity was also retrieved from attenuated total reflection- Fourier transform infrared spectroscopy (ATR-FTIR) vibrational spectra, scanning electron microscopy (SEM) micrographs, and accessibility data for the DES-treated celluloses from the two species. The crystallinity results for the fibers derived from these two Mediterranean shrubs were within the range of the results for those derived from wood pulp, opening the door to their valorization for cellulose-derived packing applications or for their use as reinforcers in composite materials in combination with other biopolymers
Sugar beet agronomic performance evolution in NW Spain in future scenarios of climate change
Changes in environmental conditions resulting from Climate Change are expected to have a major impact on crops. In order to foresee adaptation measures and to minimize yield decline, it is necessary to estimate the effect of those changes on the evapotranspiration and on the associated irrigation needs of crops. In the study presented herein, future conditions extracted from RCP4.5 scenario of IPCC, particularized for Castilla-y-León (Spain), were used as inputs for FAO crop simulation model (AquaCrop) to estimate sugar beet agronomic performance in the medium-term (2050 and 2070). A regional analysis of future trends in terms of yield, biomass and CO2 sequestration was carried out. An annual ET0 increase of up to 200 mm was estimated in 2050 and 2070 scenarios, with ETc increases of up to 40 mm/month. At current irrigation levels, temperature rise would be accompanied by a 9% decrease in yield and a ca. 6% decrease in assimilated CO2 in the 2050 and 2070 scenarios. However, it is also shown that the implementation of adequate adaptation measures, in combination with a more efficient irrigation management, may result in up to 17% higher yields and in the storage of between 9% and 13% higher amounts of CO2
Calibration and performance tests of detectors for laser-accelerated protons
We present the calibration and performance tests carried out with two detectors for intense proton pulses accelerated by lasers. Most of the procedures were realized with proton beams of 0.46-5.60 MeV from a tandem accelerator. One approach made use of radiochromic films, for which we calibrated the relation between optical density and energy deposition over more than three orders of magnitude. The validity of these results and of our analysis algorithms has been confirmed by controlled irradiation of film stacks and reconstruction of the total beam charge for strongly non-uniform beam profiles. For the spectral analysis of protons from repeated laser shots, we have designed an online monitor based on a plastic scintillator. The resulting signal from a photomultiplier directly measured on a fast oscilloscope is especially useful for time-of-flight applications. Variable optical filters allow for suppression of saturation and an extension of the dynamic range. With pulsed proton beams we have tested the detector response to a wide range of beam intensities from single particles to 3 ×105 protons per 100 ns time interval.Project funded by the Spanish Ministry of Economy and Competitiveness and co-funded with FEDER's funds within the INNPACTO 2011 program under Grant No. IPT-2011-0862-900000. This work was supported by the Spanish Plan Nacional de Investigacion Cientifica, Desarrollo e Innovacion Tecnologica (I+D+i) under Grant No. TEC 2013-48036-C3-1-R and the Valencian Local Government under Grants PROMETEOII/2013/010 and ISIC 2011/013. The work of A. J. Gonzalez is financed by CSIC with a JAE-Doc contract under Junta de Ampliacion de Estudios program, cofinanced by the European Social Fund.Peer Reviewe
Valorization of Cistus ladanifer and Erica arborea shrubs for fuel: Wood and bark thermal characterization
As a form of upgraded biomass characterized by its high energy density, low production costs, and low process energy requirements, wood pellets are an environmentally friendly fuel allowing for carbon neutral heating with high energy efficiency. In this work, the suitability of a valorization of the woods from the two most representative shrub species from the Iberian Peninsula (namely Cistus ladanifer and Erica arborea) for heating has been assessed. Whereas Erica arborea met the requirements of ISO 17225-2:2014 for ENplus-B class (the calorific content for both wood and bark was high and not significantly different, and the ash content was permissible for specimens with branch diameter ≥2,8 cm), Cistus ladanifer was in the limit of the normative and only met the requirements in terms of acceptable ash percentage (1,9%) and heating value (19 kJ·g-1) for old specimens with branch diameters >3,4 cm. Consequently, while the harvest of E. arborea for its use as fuel does not need to be selective, that of C. ladanifer should be limited to the most robust specimens and foliage should be avoided.
PDF XM
A Novel Hybrid Intelligent Classifier to Obtain the Controller Tuning Parameters for Temperature Control
This study presents a novel hybrid classifier method to obtain the best parameters of a PID controller for desired specifications. The study presents a hybrid system based on the organization of existing rules and classifier models that select the optimal expressions to improve specifications. The model achieved chooses the best controller parameters among different closed loop tuning methods. The classifiers are based on ANN and SVM. The proposal was tested on the temperature control of a laboratory stove
Prevalence of mental disorders in a population requesting health services at a primary health care center and its association with suicidal ideation and perceived disability
ABSTRACT: This study’s goal was to determine the
most prevalent mental disorders and the impact on the
perception of disability and suicidal ideation among
the population from a primary health care center in the
city of Cali. Methodology: a cross sectional study was
conducted on 254 patients who were screened with the
prime-md instrument. Descriptive statistics was used in
the analysis to determine the most frequent disorders.
Similarly, a multiple analysis with logistic and Poisson
regressions using robust variance was conducted to
determine the influence of mental disorders on disability
and suicidal ideation. Results: most patients were female,
young, and mature adults. Depression was present in
66.8% of all cases, followed by somatization disorder and
anxiety. Half of the patients had had suicidal ideations at
some point in their lives, and three out of four patients
claimed to suffer from some kind of disability. Upon
adjusting for the covariables, depression and anxiety
disorders had a strong association with suicidal ideation
and perceived disability that was overestimated by the
logistic regression. Conclusion: depression and anxiety
were the most common disorders and showed a strong
association with suicidal ideation and disability. This is
why it is necessary to screen for those disorders among
adults using primary health care services. Likewise,
we suggest considering Poisson regression with robust
variance in cross-sectional studies in health services.RESUMEN: Conocer los trastornos mentales más frecuentes
y el impacto en la percepción de discapacidad e ideación
suicida en una Institución prestadora de servicios de salud
de baja complejidad en Cali. Metodología: se realizó un
estudio transversal con 254 pacientes a los que se les
aplicó el instrumento prime-md. En el análisis se utilizó
estadística descriptiva para determinar los trastornos
más frecuentes y un análisis múltiple por regresiones
logística y de Poisson con varianza robusta para
determinar la influencia de los trastornos mentales en la
discapacidad e ideación suicida. Resultados: la mayoría
de los pacientes eran del sexo femenino, adultos jóvenes
y maduros. La depresión estuvo presente en 66.8% de
los casos, seguido del trastorno de somatización y la
ansiedad. Casi la mitad de los pacientes habían tenido
ideas suicidas alguna vez en la vida y 3 de cada 4
refirieron algún tipo de discapacidad. Después de ajustar
por covariables, los trastornos ansiosos-depresivos
mostraron una alta asociación con la ideación suicida
y la discapacidad percibida, que es sobrestimada por
la regresión logística. Conclusión: la depresión y la
ansiedad son los trastornos mas frecuentes y tienen una
alta asociación con la ideación suicida y la discapacidad
y es por esto necesario realizar tamizaciones en la
atención del adulto en servicios de baja complejidad. Se
recomienda considerar el uso de la regresión de Poisson
con varianza robusta en los estudios transversales en los
servicios de salud
- …