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The generation of a virtual, personal, auditory space to obtain a high-quality sound experience when using headphones is of great significance. Normally this experience is improved using personalized head-related transfer functions (HRTFs) that depend on a large degree of personal anthropometric information on pinnae. Most of the studies focus their personal auditory optimization analysis on the study of amplitude versus frequency on HRTFs, mainly in the search for significant elevation cues of frequency maps. Therefore, knowing the HRTFs of each individual is of considerable help to improve sound quality. The following work proposes a methodology to model HRTFs according to the individual structure of pinnae using multilayer perceptron and linear regression techniques. It is proposed to generate several models that allow knowing HRTFs amplitude for each frequency based on the personal anthropometric data on pinnae, the azimuth angle, and the elevation of the sound source, thus predicting frequency magnitudes. Experiments show that the prediction of new personal HRTF generates low errors, thus this model can be applied to new heads with different pinnae characteristics with high confidence. Improving the results obtained with the standard KEMAR pinna, usually used in cases where there is a lack of information. The authors wish to thank to the Basque Government for its support through the KK-2019-00033 METALCR2, and the University of the Basque Country UPV/EHU for its support through the MOV21/03.

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Lipase B from Candida antarctica (CALB) and lipases from Candida rugosa (CRL) and Rhizomucor miehei (RML) have been coimmobilized on octyl and octyl-Asp agarose beads. CALB was much more stable than CRL, that was significantly more stable than RML. This forces the user to discard immobilized CALB and CRL when only RML has been inactivated, or immobilized CALB when CRL have been inactivated. To solve this problem, a new strategy has been proposed using three different immobilization protocols. CALB was covalently immobilized on octyl-vinyl sulfone agarose and blocked with Asp. Then, CRL was immobilized via interfacial activation. After coating both immobilized enzymes with polyethylenimine, RML could be immobilized via ion exchange. That way, by incubating in ammonium sulfate solutions, inactivated RML could be released enabling the reuse of coimmobilized CRL and CALB to build a new combi-lipase. Incubating in triton and ammonium sulfate solutions, it was possible to release inactivated CRL and RML, enabling the reuse of immobilized CALB when CRL was inactivated. These cycles could be repeated for 3 full cycles, maintaining the activity of the active and immobilized enzymes.

The Airborne Hyper-Angular Rainbow Polarimeter (AirHARP) is a new imaging polarimeter instrument, capable of sampling a single Earth target from up to 120 viewing angles, in four spectral channels, and three linear polarization states across a 114° field of view. AirHARP is telecentric in the image space and simultaneously images three linear polarization states with no moving parts. These two aspects of the design allow for a simple and efficient quantitative calibration. Using coefficients derived at the center of the lens and the detector flatfields, we can calibrate the entire AirHARP sensor in a variety of lab, field, and space environments. We describe the calibration process for the HARP family of polarimeters using AirHARP pre-launch data. We show that this telecentric calibration technique yields a 0.25 % RMS degree of linear polarization (DOLP) accuracy in all channels for pixels around the detector center. To validate across the FOV, we compare our multi-angle reflectance and polarization data with the Research Scanning Polarimeter (RSP) over targets sampled during the NASA Aerosol Characterization from Polarimeter and Lidar (ACEPOL) campaign. For the majority of angles and targets used in the intercomparison, RSP and AirHARP agree better than 1 % in reflectance and DOLP. Therefore, our calibration successfully transfers nadir coefficients to different FOVs, given ambient challenges. This calibration technique makes the HARP design attractive for new spaceborne climate missions: HARP CubeSat (2020–2022), HARP2 (2024–) on the NASA Plankton-Aerosol-Cloud-ocean Ecosystem (PACE), Atmosphere Observing System (AOS) and beyond.

Climatic warming is projected to affect hydrology and change ice-cover periods within river channels, particularly in northern high-latitude regions. These changes will impact sediment transport conditions and longer-term riverine morphology. For example, the duration of the freezing, frozen, thawing and unfrozen periods, may affect river bank erodibility characteristics. However, it is difficult to quantify the combined impact of soil moisture, rates of freezing/thawing, and ambient temperatures on the fluvial bank erosion in addition to altered flow velocity conditions in natural river sites. We therefore present a series of scaled laboratory experiments in a controlled small-scale novel cryolab morphology facility. The flume experiments allow for detection of how these different forcing factors affect riverbank erosion rates. The ultimate goal of the experimental programme is to enhance the process understanding of the sediment transport behaviors in expected future conditions in sub-arctic environments, where the frozen periods are expected to shorten and air temperatures to rise due to climatic change. The experiments presented in this study aimed to detect how the flow velocity, soil moisture content and freezing levels of the bank sediment, affect river bank stability with altered ambient air temperatures. The laboratory experiments were performed using a small-scale Friedkin channel (1945) within a chilled flume system. A suite of experiments were conducted adjusting the ambient air temperature, the water temperature, and the water discharge (flow velocity). As the basis for creating realistic bank characteristics for the experiments, the sediment size, soil moisture and soil temperature parameter values observed in a sub-arctic Pulmanki River during mid-winter, after ice-breakup/before snow-flood peak and non-frozen conditions were used across the experimental set. The sediment bank blocks (2 cm high) were prepared for each of the experimental runs the day before, and kept in the chilled flume room overnight to match ambient temperatures prior to the runs being advanced. Overall ~130 experiments were performed. From each of the experiments the topography was measured before and after the experiment, by taking photos with a semi-automatic Canon camera. Structure from motion methodologies were used to produce surface models, and volumetric change was thus possible to calculate for each experiment. GoPro cameras (HeroBlack 10) were used to film videos of the bank evolution positioned from both nadir and sideways positions, providing linked high-resolution views of the evolving bank morphology. The data was used to detect the bank edge retreat through time. To assess changes in flow structure, buoyant micro-beads were seeded at the beginning and at the end of each experiment, allowing particle tracking velocimetry method to recover and defining the flow velocities of each experiment. Finally, a FLIR A655 thermal camera was used to aid understanding on the thermal transfers between the flow and the banks and the impact this had on morphodynamics. The preliminary results related to the possible links between temperature, moisture, flow velocity and resultant morphodynamics will be presented and the implications for climate change impacts on defrosting landscapes will be discussed.

The use of marine enzymes as catalysts for biotechnological applications is a topical subject. Marine enzymes usually display better operational properties than their animal, plant or bacterial counterparts, enlarging the range of possible biotechnological applications. Due to the fact that cytochrome P450 enzymes can degrade many different toxic environmental compounds, these enzymes have emerged as valuable tools in bioremediation processes. The present work describes the isolation, purification and biochemical characterization of a liver NADPH-dependent cytochrome P450 reductase (CPR) from the marine fish Liza klunzingeri (LkCPR). Experimental results revealed that LkCPR is a monomer of approximately 75 kDa that is active in a wide range of pH values (6–9) and temperatures (40–60 °C), showing the highest catalytic activity at pH 8 and 50 °C. The activation energy of the enzyme reaction was 16.3 kcal mol−1 K−1. The KM values for cytochrome C and NADPH were 8.83 μM and 7.26 μM, and the kcat values were 206.79 s−1 and 202.93 s−1, respectively. LkCPR displayed a specific activity versus cytochrome C of 402.07 µmol min−1 mg1, the highest activity value described for a CPR up to date (3.2–4.7 times higher than the most active reported CPRs) and showed the highest thermostability described for a CPR. Taking into account all these remarkable catalytic features, LkCPR offers great potential to be used as a suitable biocatalyst.

The configuration of the sensory quality of coffee begins in the tree, where chemical precursors are deposited and formed in the seeds as the fruits develop. Fruit within the range classified as mature can have a wide range of properties. This study evaluated three degrees of maturity and established their chemical and sensory characteristics using analytical techniques such as liquid and gas chromatography. The maturity states evaluated did not show differences in organic acids, free fatty acids, lipids, total chlorogenic acids, proteins, alkaloids or sucrose. Fructose and glucose showed differences with respect to the degree of maturity, with higher values associated with more developed states. The analysis of variance did not show a significant effect on sensory attributes or sensory quality. The chromatic coordinate a* of the CIEL*a*b* scale reached a maximum value of 25.16, and the evaluated states were different from each other.

Scedosporium; Cystic fibrosis; Serological detection Scedosporium; Fibrosi quística; Detecció serològica Scedosporium; Fibrosis quística; Detección serológica The detection of Scedosporium/Lomentospora is still based on non-standardized low-sensitivity culture procedures. This fact is particularly worrying in patients with cystic fibrosis (CF), where these fungi are the second most common filamentous fungi isolated, because a poor and delayed diagnosis can worsen the prognosis of the disease. To contribute to the discovery of new diagnostic strategies, a rapid serological dot immunobinding assay (DIA) that allows the detection of serum IgG against Scedosporium/Lomentospora in less than 15 min was developed. A crude protein extract from the conidia and hyphae of Scedosporium boydii was employed as a fungal antigen. The DIA was evaluated using 303 CF serum samples (162 patients) grouped according to the detection of Scedosporium/Lomentospora in the respiratory sample by culture, obtaining a sensitivity and specificity of 90.48% and 79.30%, respectively; positive and negative predictive values of 54.81% and 96.77%, and an efficiency of 81.72%. The clinical factors associated with the results were also studied using a univariate and a multivariate analysis, which showed that Scedosporium/Lomentospora positive sputum, elevated anti-Aspergillus serum IgG and chronic Pseudomonas aeruginosa infection were significantly associated with a positive result in DIA, while Staphylococcus aureus positive sputum showed a negative association. In conclusion, the test developed can offer a complementary, rapid, simple and sensitive method to contribute to the diagnosis of Scedosporium/Lomentospora in patients with CF. This research was funded by the Basque Government, grant numbers IT1362-19 and IT1657-22. L.M-S and M.A have received a predoctoral grant from the Basque Government and L.A-F from the University of the Basque Country (UPV/EHU).

Lipase from Thermomyces lanuginosus (TLL) has been immobilized on a methacrylate macroporous resin coated with octadecyl groups (Purolite Lifetech®® ECR8806F). This immobilization protocol gave a biocatalyst with significantly higher stability than that obtained using octyl agarose. To further improve the biocatalyst features, we tried to covalently immobilize the enzyme using this support. For this purpose, the support was activated with divinyl sulfone. The results showed that at least 1/3 of the immobilized enzyme molecules were not covalently immobilized. To solve the problem, we produced an aminated support and then activated it with divinyl sulfone. This permitted the full covalent immobilization of the previously immobilized TLL. The use of different blocking agents as the reaction endpoint (using ethylenediamine, Asp, Gly, and Cys) greatly altered the biocatalyst functional features (activity, specificity, or stability). For example, the blocking with ethylenediamine increased the ratio of the activity versus R- and S-methyl mandelate by a three-fold factor. The blocking with Cys produced the most stable biocatalyst, maintaining close to 90% of the activity under conditions where the just adsorbed enzyme maintained less than 55%. That way, this strategy to modify the support has permitted obtaining an enzyme interfacially activated versus the octadecyl layer and, later, covalently immobilized by reaction with the vinyl sulfone groups.

Sentinel-3 is an Earth observation satellite constellation launched by the European Space Agency. Each satellite carries two optical multispectral instruments: the Ocean and Land Colour Instrument (OLCI) and the Sea and Land Surface Temperature Radiometer (SLSTR). OLCI and SLSTR sensors produce images covering the visible and infrared spectrum that can be collocated in order to generate synergistic products. In Earth observation, a particular weakness of optical sensors is their high sensitivity to clouds and their shadows. An incorrect cloud and cloud shadow detection leads to mistakes in both land and ocean retrievals of biophysical parameters. In order to exploit both OLCI and SLSTR capabilities, image co-registration at ground level is needed. However, applying such collocation of the images results in cloud location mismatches due to the different viewing angles of OLCI and SLSTR, which complicates the synergistic cloud detection. This study seeks to provide a solution to correctly obtain the projected clouds based on the estimation of cloud top heights in order to better collocate clouds between sensors and detect their shadows. The study presents a forward and backward method to estimate the real nadir position of a cloud on the satellite image starting from an existing cloud mask, as well as the corresponding cloud projections on the surface depending on the solar and sensor viewing angles. The estimation of cloud top heights is based on differences in the cloud projections from SLSTR nadir and oblique views. Experimental results show that the stereo cloud matching based on maximum cross-correlation between SLSTR nadir and oblique spectra was the most robust method to match SLSTR clouds for both nadir and oblique views as compared to spectral distance and spectral angle minimization. We test the method over several images around the world, leading to higher overall accuracy (OA) as compared to Sentinel-3 official products, both in detecting SLSTR clouds and OLCI cloud shadows (SLSTR nadir OA = 93.6%, SLSTR oblique OA = 88.7%, OLCI cloud shadow OA = 93.9% for the stereo matcher, against 82.2%, 81.3% and 90.5%, respectively, for the official Sentinel-3 products). This study also provides a starting point in the development of a cloud screening approach for the upcoming Fluorescence Explorer (FLEX) satellite mission, expected to fly in tandem with Sentinel-3.

Lipase B from Candida antarctica was immobilized on heterofunctional support octyl agarose activated with vinyl sulfone to prevent enzyme release under drastic conditions. Covalent attachment was established, but the blocking step using hexylamine, ethylenediamine or the amino acids glycine (Gly) and aspartic acid (Asp) altered the results. The activities were lower than those observed using the octyl biocatalyst, except when using ethylenediamine as blocking reagent and p-nitrophenol butyrate (pNPB) as substrate. The enzyme stability increased using these new biocatalysts at pH 7 and 9 using all blocking agents (much more significantly at pH 9), while it decreased at pH 5 except when using Gly as blocking agent. The stress inactivation of the biocatalysts decreased the enzyme activity versus three different substrates (pNPB, S-methyl mandelate and triacetin) in a relatively similar fashion. The tryptophane (Trp) fluorescence spectra were different for the biocatalysts, suggesting different enzyme conformations. However, the fluorescence spectra changes during the inactivation were not too different except for the biocatalyst blocked with Asp, suggesting that, except for this biocatalyst, the inactivation pathways may not be so different.

[EN] The peer-reviewing process fosters the participation of students in class by means of the evaluation of the activities carried out by their colleagues. In order for this procedure to be successful, it is necessary to introduce the activity and motivate it properly, as well as to define detailed and specific evaluation rubrics which gather all the learning goals. This study summarizes and analyses several peer-reviewing application cases performed during Sciences courses with the aim of detecting common patterns and differences between them. After comparing the grades obtained by following this process and reviewing several surveys about it, it can be concluded that, although some marginal discrepancies exist between the scores given by the professor and the students, their involvement in the evaluation process has a positive impact in their perception of the learning level and the adequacy of the evaluation system. In this way, the students are able to identify by themselves the strong and weak aspects of their work, which results also in an increase of their critical thinking. In addition, the final grade does not depend only on the criterion of the professor, but also on the interpretation of several previously established criteria done by the participants in the activity., [ES] El procedimiento de evaluación cruzada fomenta la participación en clase de los estudiantes mediante la valoración de las actividades llevadas a cabo por sus compañeros. Para que sea útil, es necesario introducir la actividad y motivarla adecuadamente, así como definir rúbricas detalladas y concretas que recojan todos los objetivos de aprendizaje. Este estudio recopila diferentes casos de aplicación de evaluación cruzada en asignaturas de ciencias, en donde se analizan las particularidades de cada caso con la finalidad de analizar patrones comunes y diferencias, así como plantear mejoras en su aplicación futura. A través de comparativas de notas y encuestas al alumnado se demuestra que, aun existiendo ligeras discrepancias entre las calificaciones otorgadas por los alumnos y el profesor, el nivel de implicación del alumno en el proceso evaluador redunda positivamente en su percepción del nivel aprendizaje y la adecuación del sistema de evaluación. Así, el alumno es capaz de identificar por sí mismo los puntos fuertes y débiles de su trabajo, redundando en un mayor espíritu crítico. Por otra parte, la calificación no depende solo del criterio de una persona, sino de la interpretación de varias personas sobre unos criterios comunes previamente establecidos., *Este trabajo ha sido realizado en el marco del proyecto docente UV-SFPIE PID-1640839: “Docencia y evaluación a distancia: uso de herramientas propias de la UV y externas para mejorar la metodología docente en línea e híbrida en el área de ciencias”.

Manufacturing or assembly defects in gas-insulated equipment can introduce field enhancements that could lead to partial discharge (PD). This paper examines the PD characteristics of SF6 alternatives considered for potential application to retro-filling existing SF6-designed equipment. The PD performance of the C3F7CN/CO2 gas mixture and SF6 were characterised adopting the ultra-high frequency (UHF) method and investigated for different defect configurations, pressures, and gas mediums. Hemispherical rod-plane and plane-to-plane configurations with needle on the high-voltage (HV) and ground electrodes were used to mimic conductor and enclosure protrusion defects, respectively. The results demonstrate that with a needle length of 15 mm, the 20% C3F7CN/80% CO2 gas mixture had almost half the partial discharge inception and extinction voltages (PDIV/EV) of SF6. For less divergent fields, the 20% C3F7CN/80% CO2 gas mixture demonstrated a comparable PDIV/EV performance as SF6. The phase-resolved PD patterns of the 20% C3F7CN/80% CO2 gas mixture demonstrated a 3-stage transition phase that was not observed with SF6, which could be due to the discharge mechanism of the weakly attaching CO2 gas used within the mixture.

Lipase B from

ObjectivesArm weakness is common after stroke; repetitive activity is critical for recovery but people struggle with knowing what to do, volume, and monitoring progress. We studied the feasibility and acceptability of OnTrack, a digital intervention supporting arm and hand rehabilitation in acute and home settings.DesignA mixed-method, single-arm study evaluating the feasibility of OnTrack for hospital and home use. An independent process evaluation assessed the intervention’s fidelity, dose and reach. Amendments to the protocol were necessary after COVID-19.SettingAcute stroke services and home settings in North West London.Participants12 adults with a stroke diagnosis Intervention12 weeks using the OnTrack system comprising arm tracking and coaching support for self-management.Primary and secondary outcome measuresRecruitment, retention and completion rates; compliance and adherence to the intervention; reasons for study decline/withdrawal.Intervention fidelity and acceptability, evaluated through an independent process evaluation.Patient measures including activity baseline, healthcare activation, arm function and impairment collected at baseline, week 7 and week 14 of participation to assess suitability for a randomised controlled trial (RCT).Results181 individuals screened, 37 met eligibility criteria, 24 recruited (65%); of these, 15 (63%) were recruited before COVID-19, and 9 (37%) during. 12 completed the intervention (50%). Despite COVID-19 disruptions, recruitment, retention and completion were in line with prestudy expectations and acceptable for a definitive trial. Participants felt the study requirements were acceptable and the intervention usable. Fidelity of delivery was acceptable according to predetermined fidelity markers. Outcome measures collected helped determine sample size estimates and primary outcomes for an RCT.ConclusionsThe intervention was found to be usable and acceptable by participants; study feasibility objectives were met and demonstrated that a definitive RCT would be viable and acceptable.Trial registration numberNCT03944486.

Papain is a cysteine endopeptidase of vegetal origin (papaya (Carica papaya L.) with diverse applications in food technology. In this review we have focused our attention on its application in the production of bio-peptides by hydrolysis of proteins from fish residues. This way, a residual material, that can become a contaminant if dumped without control, is converted into highly interesting products. The main bioactivity of the produced peptides is their antioxidant activity, followed by their nutritional and functional activities, but peptides with many other bioactivities have been produced. Thera are also examples of production of hydrolysates with several bioactivities. The enzyme may be used alone, or in combination with other enzymes to increase the degree of hydrolysis. We gratefully recognize the support from the Ministerio de Ciencia e Innovación from Spanish Government (project number CTQ2017-86170-R) and CSIC for the project AEP045. The FPU fellowship (Ministerio de Educacion) for Mr. Morellon–Sterling is gratefully recognized. Dr. Tacias-Pascacio thanks the financial support from “Programa para el Desarrollo Profesional Docente” (PRODEP) from Mexican Government. ABM would like to thank Ministerio de Ciencia Innovación y Universidades and FEDER (Project RTI2018-095291-B-I00) and the Generalitat Valenciana (PROMETEOII/2018/076) for financial support.

Field-programmable system-on-chip (FPSoC) devices, combining high-performance processors and FPGA fabric in the same chip, are currently a leading technology in the design of complex digital systems. Since design times are longer than those of systems based on graphic processing units or standalone processors, many efforts are being devoted to develope efficient compilers from high-level languages. Even though, efficient processor-FPGA communication is still an important open issue. To contribute to this area, this article presents an extensive characterization of the processor-FPGA communication delays in Zynq-7000 devices. Although partial analyses of communication performance in these devices have been reported, this is the first work to address very important issues such as the use of DMA for data transfers or the effect of L2 cache controller settings and external RAM controller settings. As a result, data transfer rates are analyzed considering all parameters that influence them. The performance of Zynq-7000 devices is also compared to that of Cyclone V devices, hence covering the two most important current families that dominate the FPSoC market. This information is of utmost importance for designers to optimize processor-FPGA communication and, in turn, the performance of their FPSoC-based systems.

In this paper, the effect of glycerol at different concentrations and pH values on the stabilities of 13 immobilized enzymes has been analyzed. Among the enzymes, we have selected 5 lipases (immobilized on octyl or amino-glutaraldehyde supports), 3 proteases (immobilized on glyoxyl or amino-glutaraldehyde supports), 2 glycosidases, 1 laccase, 1 catalase (immobilized on glutaraldehyde matrix) and one penicillin acylase (immobilized on glyoxyl supports). The effect was completely enzyme-dependent. The results indicate that the stabilizing effect of glycerol is not universal, as in certain cases it produced even some destabilization of the immobilized enzyme (e.g., in the case of ficin extract, a protease). The glycerol effect was strongly concentration dependent (but not always the most significant results were observed at the highest glycerol concentrations), and it also strongly depends on the inactivation pH (at pH 9.0 this agent showed the strongest destabilization effects). Very interestingly, the effect of glycerol on enzyme stability was much dependent on the used immobilization protocol, which determines not only the intensity but even the sense of this effect. Thus, before using glycerol as enzyme stabilizer agent, it is necessary to confirm that the effect is positive for a specific preparation under the specific used conditions.

Racemic mixtures of twelve common a-amino acids and three chiral drugs were tested for the separation of their enantiomers by ion mobility spectrometry (IMS)-quadrupole mass spectrometry (MS). Separations were tested by introducing chiral selectors in the mobility spectrometer buffer gas. (R)-α-(trifluoromethyl) benzyl alcohol, (R)-tetrahydrofuran-2-carbonitrile, (L)-ethyl lactate, methyl (S)-2-chloropropionate, and the R and S enantiomers of 2-butanol and 1-phenyl ethanol were evaluated as chiral selectors. Experimental conditions were varied during the tests including buffer gas temperature, concentration, and type of chiral selectors, analyte concentration, electrospray voltage, electrospray (ESI) solvent pH, and buffer gas flow. The individual enantiomers yielded different drift times for periods of up to 8 hours in a few experiments; such drift times were sufficiently different (~ 0.3 ms) to partially resolve the enantiomers in racemic mixtures, but these mixtures always yielded a single mobility peak at the experimental conditions tested with a drift time similar to that of one of the enantiomers. Energy calculations of the chiral selector –ion interactions showed that these separations are unlikely using 2-butanol as chiral selector but they might be feasible depending on the nature of chiral selectors and the type of enantiomers.

Una de las condiciones esenciales para un buen proceso de aprendizaje por parte del alumnado es la motivación del mismo a la hora de afrontar las actividades propuestas por parte del equipo docente. Las nuevas generaciones de estudiantes, formadas ya por nativos digitales, nos empujan a afrontar cambios en este proceso de enseñanza-aprendizaje. Presentamos una serie de herramientas on-line que nos han permitido la realización de diversas actividades, tales como presentaciones interactivas o cuestionarios colaborativos, entre otras, que han resultado ser muy positivas a la hora de motivar al alumnado en la clase.

The advent of digital technologies and the rapid growth in access to high speed internet has revolutionized teaching and learning practices. In this work we focus on the use of video in the higher education space. In particular, we question whether short summary videos of learning objectives and exercises can be used effectively to enhance learning. We applied this methodology in an undergraduate degree course at University of Valencia and then used data logs from a learning management system, Moodle, to measure the success of video use for students.Our results indicate there is a relation between the access to educational videos and the students' academic performance, supporting educational videos can be effectively used to enhance learning.

El procedimiento de evaluación cruzada fomenta la participación en clase del estudiantado mediante la valoración de las actividades llevadas a cabo por sus compañeros y compañeras. Para que sea útil, es necesario introducir la actividad y motivarla adecuadamente, así como definir rúbricas detalladas y concretas que recojan todos los objetivos de aprendizaje. Este estudio recopila y analiza diferentes casos de aplicación de evaluación cruzada en asignaturas de Ciencias con la finalidad de detectar patrones comunes y diferencias. A través de comparativas de notas y encuestas al alumnado se demuestra que, aun existiendo ligeras discrepancias entre las calificaciones otorgadas por el profesorado y el estudiantado, la implicación de éste en el proceso evaluador redunda positivamente en su percepción del nivel de aprendizaje y la adecuación del sistema de evaluación. Así, el alumnado es capaz de identificar por sí mismo los puntos fuertes y débiles de su trabajo, lo cual implica un mayor razonamiento crítico. Por otra parte, la calificación no depende solo del criterio del profesor/a, sino también de la interpretación de las personas que participan en la actividad sobre unos criterios comunes previamente establecidos.

Estimations of Net Ecosystem Exchange (NEE) are crucial to assess the carbon sequestration/carbon source capacity of agricultural systems. Although several global models have been built to describe carbon flux patterns based on flux tower data, South American ecosystems (and croplands in particular) are underrepresented in the databases used to calibrate these models, leading to large uncertainties in regional and global NEE estimation. Despite the fact that almost half of the land surface is used worldwide for agricultural activities, these models still do not include variables related to cropland management. Using enhanced vegetation index (EVI) derived from MODIS imagery (250 m) and monthly CO2 exchange from a 9-year record of an eddy covariance (EC) flux tower in a crop field in the Inland Pampas region, we developed regression models to predict monthly NEE. We tested whether including a term for crop identity/land cover as a categorical variable (maize, soybean, wheat, and fallow) could improve model capability in capturing monthly NEE dynamics. NEE measured at the flux tower site was scaled to croplands across the Inland Pampa using crop-type maps, from which annual NEE maps were generated for the 2018–2019, 2019–2020, and 2020–2021 agricultural campaigns. The model based solely on EVI showed to be a good predictor of monthly NEE for the study region (r2 = 0.78), but model adjustment was improved by including a term for crop identity (r2 = 0.83). A second set of maps was generated taking into account carbon exports during harvest to estimate Net Biome Productivity (NBP) at the county level. Crops across the region as a whole acted as a carbon sink during the three studied campaigns, although with highly heterogeneous spatial and temporal patterns. Between 60% and 80% of the carbon sequestered was exported during harvest, a large decrease from the carbon sequestration capacity estimated using just NEE, which further decreased if fossil carbon emissions from agricultural supplies are taken into account. Estimates presented in this study are a first step towards upscaling carbon fluxes at the regional scale in a South American cropland area, and could help to improve regional to global estimations of carbon fluxes and refine national greenhouse gas (GHG) inventories.

This review summarizes the most relevant advances in the biological transformation of fatty acids (or derivatives) into hydrocarbons to be used as biofuels (biogasoline, green diesel and jet biofuel). Among the used enzymes, the fatty acid decarboxylase from Jeotgalicoccus sp. ATCC 8456 (OleT

Four commercial immobilized lipases biocatalysts have been submitted to modifications with different metal (zinc, cobalt or copper) phosphates to check the effects of this modification on enzyme features. The lipase preparations were Lipozyme®TL (TLL-IM) (lipase from Thermomyces lanuginose), Lipozyme®435 (L435) (lipase B from Candida antarctica), Lipozyme®RM (RML-IM), and LipuraSelect (LS-IM) (both from lipase from Rhizomucor miehei). The modifications greatly altered enzyme specificity, increasing the activity versus some substrates (e.g., TLL-IM modified with zinc phosphate in hydrolysis of triacetin) while decreasing the activity versus other substrates (the same preparation in activity versus R- or S- methyl mandelate). Enantiospecificity was also drastically altered after these modifications, e.g., LS-IM increased the activity versus the R isomer while decreasing the activity versus the S isomer when treated with copper phosphate. Regarding the enzyme stability, it was significantly improved using octyl-agarose-lipases. Using all these commercial biocatalysts, no significant positive effects were found; in fact, a decrease in enzyme stability was usually detected. The results point towards the possibility of a battery of biocatalysts, including many different metal phosphates and immobilization protocols, being a good opportunity to tune enzyme features, increasing the possibilities of having biocatalysts that may be suitable for a specific process.

The fishing industry generates tons of waste of great intrinsic value due to its high content of biomolecules such as proteins. The processing of proteins can result in products with high nutritional, pharmacological, and technological interest due to the peptides that can be derived from them. This review work compiles the investigations that have performed on the production of peptides from proteins of fish origin using pepsin as catalyst from the corresponding hydrolytic reaction, with special emphasis on the description of each of the reported biological properties, as well as on some uses that have been explored for these peptides. This work may be useful to promote new research involving the use of pepsin in the production of bioactive peptides from fishery products, as well as for the development of mechanisms that allow their use in different industrial processes. We gratefully recognize the financial support from Ministerio de Ciencia e Innovación-Spanish Government (project number CTQ2017-86170-R and RTI2018-095291-B-I00). Dr. Tacias-Pascacio thanks the financial support from “Instituto de Ciencia, Tecnología e Innovación del Estado de Chiapas” from Mexican Government.

In this study, a commercial enzyme cocktail designed for fruit juice clarification was immobilized on chitosan beads activated with glutaraldehyde and used for setting-up continuous packed-bed and fluidized-bed reactors. Firstly, the enzyme cocktail concentration in the immobilization process was tested to get maximum biocatalyst activity in the reaction. Then, the effect of pH and temperature on the free and immobilized enzyme cocktail stability and activity were studied. Despite the low enzyme cocktail activity recovery after immobilization (1 %), the stability of immobilized enzyme was greater compared to free enzyme, even under extreme reaction conditions. For example, when activity was measured at 90 °C and pH 4.8, the immobilized enzyme cocktail retained 80 % of its initial activity while the free enzyme retained only 35 %. Finally, the clarification capacity of the biocatalysts using orange juice was tested, providing clearer juices when performed in the fluidized-bed reactor, showing 60 % of its initial clarification capacity after 72 h of continuous use. Otherwise, the clarification rate in the packed-bed reactor decreased linearly during 54 h, probably due to the formation of dead zones and preferential paths along the bed. Pectinase immobilized on chitosan particles and used in fluidized-bed reactor seems to be a good alternative for large scale application on juice clarification.

The present work studied the synthesis of biolubricants from by-products of soybean oil processing using the lipase from Candida rugosa (CRL) both in free and immobilized forms, as biocatalysts. Soybean fatty acid distillate (SFAD) was used for first time as source of free fatty acids (FFA) to produce biolubricants via their enzymatic esterification with neopentyl glycol (NPG) and trimethylolpropane (TMP) alcohols in a solvent-free medium. The immobilization of CRL was performed via interfacial activation using a commercial hydrophobic support (Accurel) and a home-made core-shell matrix of poly(methyl methacrylate) (PMMA). Conversions of about 80 % were obtained using lyophilized CRL after 30 or 180 min using NPG and TMP, respectively. When CRL-PMMA/PMMA was used to catalyze the synthesis of NPG esters, 90 % conversion was achieved after only 6 h, whilst CRL-Accurel were more active using TMP. The biocatalysts maintained the reaction conversion during eight batches of 24 h. The lubricant properties of the products were also characterized, showing that it can be an environmentally friendly alternative for petrol lubricants

There are growing demands by the biodiesel companies to get cheap lipase formulation, preferably in liquid forms, which can give an answer to their needs. Thus, many commercial or home-produced enzymes are being used in this process in free form. Among these enzymes, Eversa is a liquid lipase formulation derived from the lipase from Thermomyces lanuginosus designed for the enzymatic biodiesel production. The potential of this promising enzyme is hereby reported. However, the specificity of lipases is a problem in biodiesel production. That way the concept of an optimal lipase for biodiesel production is not appropriate, being preferable the use of concept of combi-lipases, using Eversa as a component of the lipase mixture. The application of Eversa for the production of biodiesel through the transesterification, esterification and hydroesterification of oils and fats with different free fatty acids content is thoroughly discussed. Finally, even though Eversa was launched to be used as liquid biocatalyst in the production of biodiesel, this work will discuss how the immobilization of this enzyme through different strategies enhances its performance. That is, a properly designed immobilized Eversa biocatalyst may be more expensive, but it may have some advantages that overcome this drawback. RFL thanks the support by Spanish Ministerio de Ciencia e Innovación (grant number CTQ2017-86170-R). JCSS thanks to Brazilian Agencies for Scientific and Technological Development: Fundaçao Cearense de Apoio ao Desenvolvimento Científico e Tecnológico (FUNCAP, project number BP3-0139-00005.01.00/18), and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, project numbers 422942/2016-2 and 311062/2019-9). PWT thanks to Brazilian Agencies for Scientific and Technological Development: Sao Paulo Research Foundation (FAPESP, grant#2016/10636-8), CNPq (project numbers 405889/2016-0 and 308212/2017-7), and Coordenaçao de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001. RRCM thanks Coordenaçao de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001. The continous support supply of lipases from R. Martinez (Novozym Spain) is gratefully recognized.

High fructose syrup is a sweetener widely used as a substitute for sucrose in the food and beverage industry with its current industrial production being carried out in three sequential processes using three different enzymes that operate under different pH and temperature conditions. In this study, a single step synergistic saccharification and isomerization process has been proposed, using the commercial amyloglucosidase from Aspergillus niger immobilized by the CLEA technique (co-aggregated with magnetic nanoparticles and polyethyleneimine), and the commercial immobilized glucose isomerase (IGI) from Streptomyces murinus, Sweetzyme® IT Extra. Immobilization stabilized both enzymes, widening the operation window, thus, by applying a factorial design with a central composite rotatable design it was possible to define an optimal condition of pH and temperature of the process, as well as the best ratio between the two enzymes (pH 5.7, 50 °C and UGI/UAMG ratio of 1.56). Simultaneous saccharification and isomerization of 35 % (w/v) dextrin solution produced a Dextrose Equivalent yield over 95 %, with a glucose-to-fructose conversion around 48 % after 30 h of reaction. In addition, both biocatalysts could be reused for six consecutive cycles, maintaining glucose-to-fructose conversions without loss of activity and with easy recovery of the biocatalysts. Furthermore, because they are of different natures (magnetic CLEA of amyloglucosidase and non-magnetic IGI pellets), if one of these biocatalysts is inactivated, they can be easily separated and reloaded individually.