Sistema GPS de guiado manual para vehículos agrícolas

In this paper, the performance of a manual GPS guidance system to assist farming operations is evaluated. The distribution of granular fertilizer was simulated in order to discretize areas with excessive application of fertilizers and areas with fertilizer application rates below the intended rate. The path of travel followed by a tractor with the manual GPS guidance system was analysed and compared with a commercial parallel tracking system and without guidance assistance. In addition, the analysis evaluated how the use of manual GPS guidance systems improves the performance of field operations that require large distances between passes. Under the experimental conditions used, the best results were obtained using a commercial parallel tracking system but, for our purposes, small differences were observed between the results obtained with the commercial system and the results obtained with the developed manual GPS guidance system, getting pass-to-pass average error values of 0.26 and 0.73 m, respectively. The results obtained with both systems were significantly better than the results obtained when no guidance assistance was used. In our trials, area with appropriate fertilizer rate was clearly increased when guidance assistance was used. Values of area with correct fertilizer rate applied ranged between 87% with commercial parallel tracking and 59% without guidance assistance. The use of the manual GPS guidance system presented in this paper has proved sufficient to obtain good results for mechanical fertilizer spreadingEn este trabajo se ha evaluado un sistema de asistencia al guiado manual para la realización de labores agrícolas. Se simuló la distribución de fertilizante granulado con el objetivo de discretizar áreas con excesiva cantidad de fertilizante y áreas con cantidades inferiores a las previstas. Se comparó la trayectoria seguida por un tractor utilizando el sistema GPS de asistencia al guiado manual con un sistema comercial de guiado paralelo, y sin asistencia al guiado. Nuestro análisis ha permitido evaluar las mejoras que estos sistemas suponen para la realización de labores que requieran elevadas distancias entre pasadas. En nuestras condiciones, los mejores resultados se obtuvieron con un sistema comercial de guiado paralelo, si bien, considerando nuestro propósito, las diferencias fueron reducidas respecto a las obtenidas con el sistema de asistencia al guiado manual desarrollado, con valores medios de error pasada a pasada de 0,26 y 0,73 m, respectivamente. Los resultados obtenidos con ambos sistemas fueron significativamente mejores que los obtenidos cuando no se utiliza ningún sistema de asistencia. En nuestros ensayos, el área con dosis adecuadas de fertilizante se incrementó de forma clara con la utilización del sistema de asistencia al guiado manual. Los valores de superficie con dosis correctas de fertilizante aplicado oscilaron entre el 87% con el sistema comercial de guiado paralelo y el 59% sin asistencia al guiado. Los resultados obtenidos evidencian que el sistema de asistencia al guiado manual desarrollado es válido para la aplicación mecánica de fertilizantesFinancial support for the research was provided by the co-operative “Os Irmandiños S.C.G.” and the “Dirección Xeral de Investigación e Desenvolvemento da Xunta de Galicia” under project no. PGIDIT03RAG14ES

Diagnosis and Molecular Characterization of Chikungunya Virus Infections

In recent years, large-scale outbreaks of chikungunya arbovirus (CHIKV), which is transmitted by the Aedes mosquito, have enabled the rapid propagation of the virus across the world. After acute infection phase with commonly fever, joint pain, headache, or rash, chronic rheumatism (arthralgia or myalgia, anorexia, and concentration disorders) up to 40% of cases is observed. The chronic form is defined by symptoms persisting for more than 3 months, and up to years, after initial diagnosis. Chronic discomfort has been linked to one of the four genotypes described. These genotypes represent different geographic lineages (classification based on partial sequence of viral E1 glycoprotein): West African, East-Central-South-African (ECSA), ECSA-diverged or Indian Ocean Lineage (IOL), and Asian. The first marker detected in CHIK infection is the viral RNA, usually by reverse transcription-polymerase chain reaction (RT-PCR). This marker can be identified in samples within 8 days of symptom onset. The infection can also be diagnosed with serological testing to detect CHIKV-specific immunoglobulin IgG and/or IgM. Sequencing studies can determine the infecting genotype

Working Group on Mackerel and Horse Mackerel Egg Surveys (WGMEGS). 2021

WGMEG

Performance Study of a Torsional Wave Sensor and Cervical Tissue Characterization

A novel torsional wave sensor designed to characterize mechanical properties of soft tissues is presented in this work. Elastography is a widely used technique since the 1990s to map tissue stiffness. Moreover, quantitative elastography uses the velocity of shear waves to achieve the shear stiffness. This technique exhibits significant limitations caused by the difficulty of the separation between longitudinal and shear waves and the pressure applied while measuring. To overcome these drawbacks, the proposed torsional wave sensor can isolate a pure shear wave, avoiding the possibility of multiple wave interference. It comprises a rotational actuator disk and a piezoceramic receiver ring circumferentially aligned. Both allow the transmission of shear waves that interact with the tissue before being received. Experimental tests are performed using tissue mimicking phantoms and cervical tissues. One contribution is a sensor sensitivity study that has been conducted to evaluate the robustness of the new proposed torsional wave elastography (TWE) technique. The variables object of the study are both the applied pressure and the angle of incidence sensor–phantom. The other contribution consists of a cervical tissue characterization. To this end, three rheological models have fit the experimental data and a static independent testing method has been performed. The proposed methodology permits the reconstruction of the mechanical constants from the propagated shear wave, providing a proof of principle and warranting further studies to confirm the validity of the results.This research was supported by the Ministry of Education DPI2014-51870-R, DPI2010-17065 and UNGR15-CE-3664, Ministry of Health DTS15/00093 and PI16/00339, and Junta de Andalucía P11-CTS-8089 projects. Modesto T. López-López acknowledges financial support by the project FIS2013-41821-R (Ministry of Economy and Competitiveness, co-funded by the ERDF, European Union). We acknowledge the collaboration of the members of the Anatomical Pathology Unit of the University Hospital Complex of Granada. Finally, Antonio Callejas is grateful to the University of Granada for the award of an PhD fellowship

Calculation of mackerel adult parameters for the application of the DEPM in the western spawning area

The ICES Working Group on Mackerel and Horse Mackerel Egg Surveys (WGMEGS) coordinates the mackerel and horse mackerel egg survey in the Northeast Atlantic (NEA) and the mackerel egg survey in the North Sea. The working group plans and reports on these surveys, with recent attention focused on the execution of the surveys given the increasing demands related to covering the expanding survey area as well as balanced fecundity sampling. WGMEGS also addresses data quality assurance in macke-rel fecundity and total annual egg production estimation.Currently, there are 3 surveys in place which are carried out triennially and deliver standing stock bio-mass (SSB) indices: (1) the survey for the western and southern stock components of the NEA mackerel stock, as well as for the western horse mackerel stock, (2) the survey for the NEA mackerel North Sea stock component, and (3) the survey for the southern horse mackerel stock.For the North Sea component, the egg survey in 2017 revealed an estimated egg production of 201*1012, resulting in an SSB of 287*103 tons. This is a strong increase of more than 100*103 tons com-pared to 2015 (SSB = 170*103 tons). While peak spawning in the North Sea was covered, the coverage of the complete spawning season and area was insufficient to produce a reliable estimate of survey in-dices.In 2019, the application of an alternate transect survey design made it possible to survey the persis-tently expanding mackerel spawning area and season. Northern and northwestern spawning bounda-ries for mackerel during survey periods 5 (weeks 19 – 22) and 6 (weeks 23 – 26) were not fully deline-ated. Peak spawning was observed in period 4 (weeks 16 – 18). Subsequent analyses of survey results in conjunction with results from exploratory surveys in the inter-survey-years showed that the mackerel core spawning area was covered and a reliable estimate of mackerel annual egg production was deliv-ered. The estimate of total mackerel egg production was 1.64*1015, which is a decrease of 7.6% com-pared to that of 2016 (rev. 1.77*1015).Realized fecundity was estimated at 1147 per g female, revealing the SSB for the NEA mackerel stock in 2019 at 3.09 million tons indicating at 12 % decrease since the 2016 survey (SSB = 3.52 million tons). At only 1.78*1014 , total annual egg production (TAEP) in western horse mackerel was found to be lowest production reported in the time series since 1992. The spawning maximum was detected in the last pe-riod 7 (weeks 27 – 29). It can, thus, not be concluded that peak spawning and the entire temporal ex-tent of horse mackerel spawning had been sufficiently covered.To further improve the quality of the index time series, WGMEGS will continue to dedicate much of its work to survey design and quality assurance in mackerel egg production and fecundity estimation

Impact of the COVID-19 pandemic on hepatitis B and C elimination: An EASL survey

Hepatitis B virus; Hepatitis C virus; COVID-19 pandemicVirus de la hepatitis B; Virus de la hepatitis C; Pandemia de COVID-19Virus de l'hepatitis B; Virus de l'hepatitis C; Pandèmia del COVID-19Background & Aims The World Health Organization (WHO) HBV and HCV elimination targets, set in 2016 and based on projections to 2030, were unable to consider the impact of intervening factors. To evaluate the impact of the COVID-19 pandemic on viral hepatitis elimination programs, the European Association for the Study of the Liver (EASL) conducted a survey in liver centers worldwide in 2021. Methods A web-based questionnaire was distributed (May-July 2021) to all EASL members representing clinical units providing HBV and HCV hepatitis care. Results are expressed as absolute numbers and reduction rates for each care activity. Results Data were collected from 32 European and 12 non-European clinical centers. Between January 2019 (pre-pandemic) and December 2020 (during the pandemic), chronic HBV consultations decreased by 32% and 26%, new referrals by 38% and 39%, HBV testing rates by 39% and 21% (for HBsAg detection) and 30% and 22% (for HBV DNA detection), and new HBV treatments by 20% and 44% (p = 0.328) in European and non-European centers, respectively. With regard to HCV during the same time frame, the overall reductions were 39% and 50% for consultations, 49% and 49% for new referrals, 11% and 38% for HCV RNA detection, and 51% and 54% for new HCV antiviral treatments for European and non-European Centers, respectively (p = 0.071). Conclusions All steps in the viral hepatitis care cascade have been hampered by the COVID-19 pandemic, with a comparable impact across different centers. These data reaffirm the pandemic’s major effect on global viral hepatitis elimination programs and suggest that actions to achieve the WHO 2030 targets should be reconsidered and revised to account for each country's progress relative to pre-pandemic values

Palladium nanoparticles synthesized by laser ablation in liquids for antimicrobial applications

Antibiotic resistance is a leading cause of death worldwide. In this paper, we explore new alternatives in the treatment of infections. Noble metal nanoparticles could help to mitigate this problem. In this work, palladium nanoparticles were synthesized by laser ablation in order to explore their antimicrobial capacity. To obtain palladium nanoparticles, a palladium plate immersed in water, or methanol, was ablated, using two pulsed lasers that emit radiation with wavelengths of 532 nm and 1064 nm, respectively. Pure Pd-NPs with crystalline microstructure and rounded shape were obtained. The nanoparticles’ size is more homogeneous if the laser wavelength is 532 nm, and it decreases when methanol is used as solvent, reaching mean diameters smaller than 6 nm. With the objective of studying antimicrobial activity against Staphylococcus aureus, the Pd-NPs were immobilized on the surface of titanium discs. The release of palladium ions was recorded during the first seven days, and the cytotoxicity of the immobilized NPs was also tested with L929 mouse fibroblast cell line. Palladium nanoparticles synthesized by means of the infrared laser in methanol showed a strong inhibitory effect on S. aureus and good cytocompatibility, with no toxic effect on fibroblast cells.Peer ReviewedPostprint (published version

High contrast laser marking of alumina

Alumina serves as raw material for a broad range of advanced ceramic products. These elements should usually be identified by some characters or symbols printed directly on them. In this sense, laser marking is an efficient, reliable and widely implemented process in industry. However, laser marking of alumina still leads to poor results since the process is not able to produce a dark mark, yielding bad contrast. In this paper, we present an experimental study on the process of marking alumina by three different lasers working in two wavelengths: 1064 nm (Near-infrared) and 532 nm (visible, green radiation). A colorimetric analysis has been carried out in order to compare the resulting marks and its contrast. The most suitable laser operating conditions were also defined and are reported here. Moreover, the physical process of marking by NIR lasers is discussed in detail. Field Emission Scanning Electron Microscopy, High Resolution Transmission Electron Microscopy and X-ray Photoelectron Spectroscopy were also employed to analyze the results. Finally, we propose an explanation for the differences of the coloration induced under different atmospheres and laser parameters. We concluded that the atmosphere is the key parameter, being the inert one the best choice to produce the darkest marks.Xunta de Galicia | Ref. CN2012/29

Continuous fiberizing by laser melting (Cofiblas): production of highly flexible glass nanofibers with effectively unlimited length

The development of nanofibers is expected to foster the creation of outstanding lightweight nanocomposites and flexible and transparent composites for applications such as optoelectronics. However, the reduced length of existing nanofibers and nanotubes limits mechanical strengthening and effective manufacturing. Here, we present an innovative method that produces glass nanofibers with lengths that are, effectively, unlimited by the process. The method uses a combination of a high-power laser with a supersonic gas jet. We describe the experimental setup and the physical processes involved, and, with the aid of a mathematical simulation, identify and discuss the key parameters which determine its distinctive features and feasibility. This method enabled the production of virtually unlimited long, solid, and nonporous glass nanofibers that display outstanding flexibility and could be separately arranged and weaved.Xunta de Galicia | Ref. ED431C 2019/23Xunta de Galicia | Ref. ED481B 2016/047-0Xunta de Galicia | Ref. ED481D 2017/010European Union | Ref. EAPA_151/2016 Interreg Atlantic AreaAgencia Estatal de Investigación | Ref. PGC2018-094900-B-I0