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Las medianas empresas representan un sector importante en la economía del país, tanto por su contribución en términos monetarios como por el número de empleos que proporciona, además del importante nivel de flexibilidad en sus procesos, que les permite adaptarse constantemente a las demandas del mercado. En algunos países, la integración de agrupaciones de medianas empresas ha dado como resultado el establecimiento de redes de empresas o empresas integradoras, que han favorecido su permanencia y consolidación, generando mayor competitividad. La adopción de alternativas de cooperación empresarial como las fusiones, empresas integradoras, conglomerados y alianzas estratégicas, que brinden la posibilidad de enfrentar a la competencia a través del fortalecimiento productivo y comercial, se ha convertido en un tema obligado para que las medianas empresas se mantengan en el mercado nacional e internacional. En el presente trabajo, se aborda la problemática de las medianas empresas del ramo alimenticio ubicadas en Morelia, Michoacán, el cual es resultado de una investigación para determinar si a través de la formación de las alianzas estratégicas se incrementa la competitividad internacional de este sector empresarial o si existe algún tipo de correlación entre estas dos variables, lo que permitirá, finalmente, realizar una propuesta de solución.

Esta investigación hace un análisis comparativo de las empresas vitivinícolas exportadoras de Valle de Guadalupecon las empresas de este tipo en el resto del Estado de Baja California, México. El objetivo es determinar cuálesson los factores que permiten a estas empresas incrementar las exportaciones de Vino Tinto; además de conocerla evolución que éstas han tenido después de la pandemia COVID 19. Para el análisis estadístico se utiliza elmodelo de ecuaciones estructurales Partial Least Squares (PLS-SEM), incluyendo la evaluación del poderpredictivo fuera de muestra mediante PLSpredict. La metodología utilizada incluye un análisis cualitativo de lasituación actual de su entorno y un estudio cuantitativo de datos resultado de la aplicación de un instrumento de41 ítems a 175 empresas vitivinícolas, divididas en dos universos. El primer grupo consta de 92 empresas que seubican en la región de Valle de Guadalupe y el segundo incluye las 83 localizadas en el resto de los municipios. Losprincipales hallazgos muestran que la variable que presenta un mayor grado de asociación es Competitividad y unmenor grado Producción. Las principales limitaciones encontradas son: la escasez del recurso hídrico, la falta derecursos nancieros, la producción limitada, los pocos apoyos económicos del sector público y privado, así como lainsuciente inversión en innovación tecnológica.

This research analyzes the exports of wine companies in the Valle de Guadalupe region in the State of Baja California, Mexico. The objective is to determine the factors that induce strategic decision making to achieve a high-performance level of productive capacity. The hypothesis suggests that production, technological innovation, and competitiveness are the factors that favor the exports of these wine companies. For the statistical analysis, Partial Least Squares structural equation modeling (PLS-SEM) is used, including the evaluation of the out-of-sample predictive power by means of PLS predict. The methodology used includes a qualitative analysis of the current situation on the subject and a quantitative study of data obtained by applying a 41-item instrument to ninety-two companies. The main findings show that the variable that presents a higher degree of association is competitiveness and the variable that presents a lower degree is production. Another finding is that there is a need to strengthen collaborative projects with a Cluster Approach, in which the collaboration network between these companies, government agencies, wine associations and educational institutions must be actively involved. The main strategies proposed are three: the first in relation to competitiveness is to improve operational planning to increase productivity. The second is to achieve a more competitive price by purchasing supplies collaboratively between companies; the existing common bond and business cooperation will allow exports to increase. The third is to manage a greater participation of the government, in terms of financing and support, investment in highway infrastructure, reduction of taxes on this item and the sustainable administration of the State's water resources.

We assessed the association between measures of dynamic visual acuity and a multiple object tracking task in physically active young adults. Ninety-four young adults performed the dynamic visual acuity and multiple object tracking tasks. Dynamic visual acuity was measured for horizontal and random walk motion paths at four target speeds (5, 10, 20, and 30°/s). For the multiple object tracking task, participants had to track three out of eight balls for 10 s, and the object speed was adjusted by a staircase procedure. We found that multiple object tracking performance was associated with better identification of horizontally and randomly moving targets in the dynamic visual acuity test ( p 0.170 in all cases). This study provides novel insights into the association between the ability to identify horizontally and randomly moving targets and track multiple objects. Future studies are needed to determine the potential utility of dynamic visual acuity for talent identification and predicting sports performance in real-game situations.

Las innovaciones y el desarrollo tecnológico tienen un impacto local, económico y social importante, por lo que se vuelve relevante el fomento de procesos de I+D+i en las regiones. Las universidades constituyen uno de los centros encargados de generación de nuevos conocimientos que propician dichos procesos, esos nuevos conocimientos la llevan a buscar su aplicabilidad para la satisfacción de necesidades sociales. Uno de los mecanismos existentes para dicha aplicabilidad corresponde a spin-off universitarias de base tecnológica que representan nuevas empresas creadas a partir de la universidad resultado de conocimientos científicos y técnicos en ciencias e ingenierías. Es así como el objetivo de la presente investigación consiste en caracterizar a las spin-off universitarias de base tecnológica, de una universidad pública del estado de Guanajuato. El estudio corresponde a un estudio de caso, con un enfoque cualitativo empleando el diseño etnográfico; se realizaron un total de veinticuatro entrevistas a profundidad a spin-off universitarias de base tecnológica de una universidad pública del estado de Guanajuato, colaboradores de estas y a personal universitario de áreas de vinculación, extensión, proyectos y posgrados. Los resultados se agruparon en tres familias de códigos y veintidós categorías de análisis, destacándose que pueden surgir de manera planeada y no planeada. La institución de la que se desprende la spin-off es la universidad. Cuentan con figura jurídica propia, con una estructura financiera de asociados, joint venture o propia y el titular de la empresa es o fue el inventor/emprendedor y trabaja o trabajó en la universidad.

Purpose: The use of swimming goggles (SG) has demonstrated to alter different ocular parameters, however, the impact of wearing SG on the tear film stability remains unknown. The main objective of this study was to determine the short-term effects of wearing SG on tear film surface quality break-up time (TFSQ-BUT). Methods: Twenty-eight young healthy adults (14 men and 14 women) wore a drilled SG, and TFSQ-BUT was measured before, during and after SG use. Dynamic-area high-speed videokeratoscopy was used for the non-invasive assessment of TFSQ-BUT. Results: TFSQ-BUT was significantly reduced while SG wear in comparison to the baseline measurement (4.8 ± 4.5 s vs. 8.8 ± 6.9 s; corrected p-value = 0.017, d = 0.57, mean difference = 4.0 [0.6, 7.3]; 45% reduction). Immediately after SG removal, TFSQ-BUT rapidly recovered baseline levels (8.2 ± 5.9 s vs. 8.8 ± 6.9 s; corrected p-value = 0.744). The impact of wearing SG on TFSQ-BUT were independent of the gender of the participants (p = 0.934). Conclusion: The use of SG induces a TFSQ-BUT reduction, with these changes returning to baseline levels immediately after SG removal. These data may be of relevance for the management of dry eye patients, who need to avoid circumstances that exacerbate tear film instability. Nevertheless, these results must be interpreted with caution since the experiment did not entirely mimic real-life conditions (e.g., eye cup piece drilled, time of exposure, environmental conditions). Future studies should consider the inclusion of dry eye patients and older individual in order to explore the generalizability of these findings.

Purpose: The ±2.00 D accommodative facility test presents several limitations, in- cluding the lack of objective information and inherent characteristics such as ver- gence/accommodative conflict, change in apparent size of the image, subjective criteria for judging blur and motor reaction time. By using free-space viewing con- ditions and an open-field autorefractor to monitor the refractive state, we exam- ined the impact of manipulating these factors on the qualitative and quantitative assessment of accommodative facility. Methods: Twenty-five healthy young adults (24.5 ± 4.5 years) took part in this study. Participants performed three accommodative facility tests (adapted flipper, 4D free-space viewing and 2.5D free-space viewing) under both monocular and binocular conditions in random order. A binocular open-field autorefractor was used to assess the accommodative response continuously, and these data were used to characterise accommodative facility quantitatively and qualitatively. Results: There were statistically significant differences between the three testing methods both quantitatively (p < 0.001) and qualitatively (p = 0.02). For the same accommodative demand, a lower number of cycles was obtained for the adapted flipper condition in comparison with the 4D free-space viewing test (corrected p-value < 0.001, Cohen's d = 0.78). However, this comparison did not reach statisti- cal significance for qualitative measures of accommodative facility (corrected p- value = 0.82, Cohen's d 0.05). Conclusions: These data provide evidence that the qualitative assessment of ac- commodative facility is not influenced by the inherent limitations of the ±2.00 D flipper test. The use of qualitative outcomes by incorporating an open-field au- torefractor allows examiners to increase the validity of the accommodative facility test in both clinical and research settings.

Innovation is a fundamental strategy to generate and maintain a competitive position in the market, however, the companies’ ability to generate innovations is not an easy task, as there are different factors that influence it. Although several innovation models have been developed, no ad hoc models have been proposed to the conditions of micro and small enterprise, nor the structural conditions in developing countries. Therefore, the objective of this research is to identify and analyze the most relevant management factors that drive innovation in Mexican micro and small business. To this end, 594 micro and small businesses from the Laja-Bajío region belonging to the commercial sector, service and manufacture, were surveyed. Semi-structured interviews were conducted to identify their needs on innovation generation. The results show that technology management, marketing strategies and human resources management are the key elements to drive innovation in the MSEs (Micro and Small enterprises).

The general objective of this research work is to know if the university context, attitudes, norms, and perception of behaviour control influence the intention of social entrepreneurship and social innovation in undergraduate students from the areas of economics, administrative and social. The methodology was based on the Global Survey of University Entrepreneurship Students -GUESSS- in which 34 countries have participated since 2011, with a sample of more than 150,000 students per year. The results by lineal regression and R show that the university context, attitude towards behaviour and subjective norms have a low influence on entrepreneurial intentions. However, they should not be neglected since they generate an effect on entrepreneurial intentions, which is important to highlight in the perceived behavioural control of the ease or difficulty of becoming an entrepreneur.

Funding Open Access funding provided thanks to the CRUECSIC agreement with Springer Nature. Funding for open access charge: Universidad de Granada / CBUA., Background Acute caffeine ingestion has been associated with improvements in cognitive performance and visual functioning. The main objective of this study was to determine the effects of caffeine intake on dynamic visual acuity (DVA). Methods Twenty-one low caffeine consumers (22.5 +/- 1.6 years) took part in this placebo-controlled, double-blind, and balanced crossover study. In two different days and following a random order, participants ingested either caffeine (4 mg/kg) or placebo, and DVA was measured after 60 min of ingesting the corresponding capsule. A recently developed and validated software (moV& test, V&mp Vision Suite, Waterloo, Canada) was used to assess DVA. Results We found a greater accuracy for both the horizontal and random motion paths of DVA after caffeine ingestion (p < 0.001 and p = 0.002, respectively). In regard to the speed of the response, our data revealed that caffeine intake was associated with a faster reaction time for horizontally (p = 0.012) but not for randomly (p = 0.846) moving targets. Also, participants reported higher levels of perceived activation after consuming caffeine in comparison to placebo (p < 0.001). Conclusions Our data suggest that caffeine intake (i.e., a capsule containing 4 mg/kg) has an ergogenic effect on DVA, which may be of special relevance in real-word contexts that require to accurately and rapidly detect moving targets (e.g., sports, driving, or piloting)., CRUE-CSIC agreement, Springer Nature, Universidad de Granada / CBUA

The objective of this research is to examine some of the theories of competitiveness and technological innovation that allow wine companies to develop internationalization strategies in the current framework of economic globalization. The implementation of these strategic decisions not only requires research efforts, but it also requires the participation of the collaborative network of the segments related to productive infrastructures. In Mexico, the wine sector presents a growth perspective due in part to the differentiation and expansion of the markets, but it also presents challenges of product offer, financing for the growth of the company and government policies such as the reduction of taxes that would allow the sector increase competitiveness. The methodology of this study is of an exploratory descriptive nature, since it aims to serve as theoretical support so that companies have the information that allows them to design the necessary internationalization strategies to have a dominant market share presence at the national and international level. The contribution of the qualitative analysis of this work lies in the dissemination of information on the subject, the debate of the concepts and the development of these competences; both at the business and academic level.

Clinical relevance: Caffeine intake has been demonstrated to influence several physiological measures, including some related to eye physiology. The ability to focus at different distances is of paramount importance in real-world situations, and thus, the possible impact of caffeine intake on accommodative facility may have important clinical implications. Background: This placebo-controlled, double-blind, balanced crossover study aimed to assess the acute effects of caffeine ingestion on the frequency and precision of the binocular accommodative facility. Methods: Twenty university students (21.9 ± 3.4 years) ingested a capsule of caffeine (4 mg/kg) or placebo (300 mg of corn-starch) on two different days and counterbalanced order. The binocular accommodative facility was objectively assessed, using the WAM-5500 binocular open-field autorefractometer, after 60 min of capsule ingestion (caffeine/placebo). Perceived levels of activation was also assessed in each experimental condition. Results: The ingestion of a single administration of caffeine (~ 4 mg/kg) causes an increase in the number of cycles performed per minute (p = 0.023, Cohen’s d = 0.55), whereas no effects were observed for the mean magnitude of accommodative change between the far and near targets (p = 0.794), and the percentage of incorrect cycles of accommodation and dis-accommodation (p = 0.271 and 0.396, respectively). Participants reported a perceived level of activation of 6.8 ± 1.5 and 7.6 ± 1.8 in the placebo and caffeine conditions, respectively (p = 0.059). Conclusion: Caffeine intake improves quantitative, but not qualitative, measures of accommodative facility. These results corroborate the impact of caffeine on visual function and suggest that this ergogenic effect of caffeine may be used to enhance visual performance in applied situations.

El presente artículo fue realizado con la finalidad de identificar las principales preferencias turísticas que tienen los visitantes en sus recorridos turísticos por las provincias de Pichincha, Napo y Orellana pertenecientes a la zona de planificación 2 - centro norte del Ecuador en el escenario actual de Covid-19. La metodología trabajada, mediante el uso de métodos cuantitativos y cualitativos, permitió el reconocimiento del comportamiento turístico en cuanto a gasto, frecuencia, ocupación, estadía, duración de viaje; así como tendencias, concentraciones y flujos turísticos, los cuales se reflejaron a través de estadísticas complementadas con el uso de sistemas de información geográfica SIG. Con base en esto se determinó una disminución considerable en los flujos turísticos que arriban a la zona 2, así como nuevas tendencias y preferencias de viaje directamente relacionadas con la pandemia mundial, que destacan el turismo de proximidad con un segmento de mercado mayoritariamente joven de 16 a 35 años.

Esta obra editorial se orienta bajo tres objetivos de investigación cualitativa. El primero que consistió en describir la manera en que se relacionan la universidad, la empresa y el gobierno, para impulsar la creación empresas, en una universidad pública del estado de Guanajuato. La investigación cualitativa se centró en un estudio de caso y en un diseño etnográfico. Se realizaron un total de 27 entrevistas a profundidad, divididas en ocho spin-off universitarias de base tecnológica, 12 a colaboradores de estas, cuatro a personal universitario de áreas de vinculación, extensión, proyectos y posgrados, y tres a personal de dependencias de gobierno encargadas de temas de tecnología, investigación, desarrollo e innovación. El segundo consistió en analizar los factores que influyen en la generación de spin-off universitarias de base tecnológica, en una universidad pública del estado de Guanajuato y por último, el tercer objetivo fue describir las características de las spin-off universitarias de base tecnológica.

There is scientific evidence that an individual's beliefs and/or expectations play a role in the behavioural and physiological response to a given treatment. This study aimed to assess whether the dynamics of the accommodative response and stereoacuity are sensitive to experimentally induced placebo and nocebo effects.Nineteen healthy university students performed three experimental sessions (placebo, nocebo and control) in randomised order, with the dynamics of the accommodative response (magnitude and variability), stereoacuity and subjective measures being assessed in all sessions. For the experimental manipulation, participants ingested an inert capsule that was alleged to have positive (white capsule, placebo condition) or negative (yellow capsule, nocebo conditions) effects on the human physiology. In the control condition, participants did not ingest a capsule.The data revealed that the variability of accommodation was sensitive to experimentally induced placebo and nocebo effects, showing a more stable accommodative response for the placebo compared with the nocebo condition (corrected p-value = 0.04, Cohen's d = 0.60). In addition, better stereoacuity was found with the placebo, compared with the nocebo (corrected p-value = 0.01, Cohen's d = 0.69) and control (corrected p-value = 0.03, Cohen's d = 0.59) conditions. Successful experimental manipulation was confirmed by the analysis of subjective perceptions.These findings provide evidence that manipulating expectations about the efficacy of an inert treatment affect the dynamics of the accommodative response (variability of accommodation) and stereoacuity. The results have important applications in both clinical and research outcomes, where individuals´ beliefs/expectations could modulate the visual function.

This paper presents the results of an investigation about the foreign tourist affluence in the state of Michoacán. The objective of the research is to identify the main causes of the lack of growth in the tourist influx in Michoacán. A survey was carried out in which a questionnaire was applied to 380 foreign tourists who visited the state in the period of October-November 2019. A Likert scale was used and for the analysis of the results the SPSS program (Statistical Package for the Social Sciences). The obtained results showed that the low tourist competitiveness, the lack of investment in the tourist infrastructure and the little diversification in the tourist offer have prevented the increase of the tourist affluence in the state. Finally, a Comprehensive Tourism Planning Model was proposed as a solution to the detected problem.

Appropriate visual function is paramount to ensuring adequate driving performance and road safety. Here, we examined the influence of sudden artificially-impaired binocular vision on driving performance using a car simulator. Twenty-four young drivers (mean age 22.42

La terapia de compresión se puede aplicar con diversos dispositivos, entre los que se incluyen vendajes, sistemas de compresión neumática secuencial, dispositivos de velcro autoajustables, medias de compresión y los sistemas 2 en 1 compuestos por dos calcetines. Las principales indicaciones clínicas de las medias de compresión son la prevención y/o el tratamiento de los síntomas de la insuficiencia venosa primaria y el síndrome postrombótico, así como el linfedema y el lipedema. Tan solo a una minoría de los pacientes que necesitaría terapia de compresión a largo plazo se les llegan a prescribir. La inexperiencia, la falta de formación y la gran cantidad de materiales diferentes son consideradas como obstáculos por el profesional para la recomendación de medias. Por otro lado, también existe una escasa adherencia terapéutica por parte de los pacientes. El objetivo de este trabajo fue identificar y analizar las recomendaciones que ofrecen las principales guías y documentos basados en evidencias científicas para ayudar a los profesionales sanitarios a prescribir la media más adecuada para cada persona y conseguir los mejores resultados. Para ello, se han consultado 7 documentos basados en evidencias científicas. Las lagunas de conocimiento detectadas, sumadas a la confusión que se deriva de la variedad de tipos de medias disponibles, de la diversidad de condiciones clínicas que pueden requerir sus uso y de la variabilidad de situaciones personales que puede presentar cada paciente, hacen que las recomendaciones de las guías actualmente vigentes resulten insuficientes para resolver las dudas que surgen a la hora de prescribir medias de compresión.

PReCIS:: Greater intraocular pressure (IOP) values are observed when reading in the supine position in comparison with the sitting position, and thus, it should be considered by eye care specialists for the management of glaucoma patients or those at risk. PURPOSE IOP is sensitive to near work and body position, however, the influence of the body position adopted while performing near tasks remains unknown. This study aimed to assess the IOP changes induced by reading on a smartphone in sitting and supine position, and to explore whether these IOP changes differ between men and women. METHODS Twenty-four healthy young adults (12 men and 12 women) read a text on a smartphone placed at 30 cm for 25 minutes while lying down and sitting in 2 different days. A rebound tonometer, which allows assessing IOP in the supine position, was used to measure IOP before reading, during reading (5, 15, and 25 min), and after 5 minutes of recovery. Complementarily, the authors checked the level of sleepiness/alertness before reading, and the perceived levels of fatigue and discomfort after reading. RESULTS The data showed that reading induces an IOP rise [P

To evaluate the acute effect of caffeine consumption on the accuracy and variability of accommodation, as well as its impact on pupil size and perceived levels of activation.22 university students (21.68 ± 3.67 years old) ingested a capsule of caffeine (4 mg/kg) or placebo (300 mg of corn-starch) in two different days and counterbalanced order. After 30 min of capsule ingestion, we objectively measured the accuracy and variability of accommodation, and pupil size using the WAM-5500 binocular open-field autorefractometer for 2 min at each of the six viewing distances (5 m, 50 cm, 40 cm, 33 cm, 25 cm, and 20 cm). Subjective levels of activation to check the effectiveness of caffeine/placebo manipulation were also reported.We found that after 30 min of caffeine/placebo ingestion, participant perceived higher levels of activation in the caffeine condition (Our data suggest that caffeine consumption reduced the variability of accommodative response and induced pupil dilation. Nevertheless, the accuracy of accommodation was insensitive to caffeine intake. These findings may be explained by the bidirectional relationship between ocular functioning and the nervous system´s state of activation.

Funding for open access charge: Universidad de Granada/CBUA. The authors have no financial or proprietary interest in a product, method or material described herein. The article has not been presented in a meeting., Purpose This study aimed to assess the impact of wearing swimming goggles (SG) on corneal biomechanics. Methods Corneal deformation response, central corneal thickness (CCT), intraocular pressure (IOP) and biomechanically corrected intraocular pressure (bIOP) were measured with the Corvis system (Oculus Optikgeräte GmbH, Wetzlar, Germany) in thirtyone healthy young adults while wearing a drilled SG. All measurements were obtained before, at 30 s, 2 min, 3.5 min and 5 min of wearing SG, just after SG removal and after 2 min of SG removal. Results The corneal biomechanics is sensitive to SG wear, observing lower corneal deformability during SG use. Specifically, wearing SG caused an increase in the time and length of the first applanation and radius curvature at the highest concavity, as well as a decrease and in the velocity of the first applanation and time and deformation amplitude of the second applanation (p < 0.001 in all cases). After SG removal, corneal biomechanical parameters showed a rebound-effect, obtaining a higher corneal deformability in comparison with baseline reading (p-corrected < 0.05 in all cases). Additionally, IOP and bIOP significantly increased while wearing SG (p < 0.001 in both cases), whereas CCT remained stable (p = 0.850). Conclusions Wearing SG modifies the biomechanical properties of the cornea, with reduced corneal deformability during SG wear. The outcomes of this study should be taken into consideration when making clinical decisions in subjects at high risk of developing corneal ectasias or glaucoma, as well as in the post-surgical management of these ocular conditions., Universidad de Granada/CBUA

Purpose: We aimed to assess the impact of drinking water (500 and 1000 mL) on corneal biomechanics and determine the level of association between changes in intraocular pressure and variations in the different biomechanical properties of the cornea. Methods: A total of 39 healthy young adults ingested either 1000 mL (n = 21) or 500 mL (n = 18) of tap water in 5 min. The CorVis ST system was used to assess corneal biomechanics at baseline and at 15, 30, and 45 min after water ingestion. Results: Water drinking induced statistically significant changes in the deformation amplitude (P < 0.001, η² = 0.166), highest concavity time (P = 0.012, η² = 0.093), peak distance (P < 0.001, η² = 0.171), time and velocity of the first applanation (P < 0.001, η² = 0.288 and P = 0.016, η² = 0.087, respectively), and time and velocity of the second applanation (P = 0.030, η² = 0.074 and P = 0.001, η² = 0.132, respectively), being independent of the amount of water ingested (P > 0.05 in all cases). There were significant associations between changes in intraocular pressure and some parameters of corneal biomechanics. Conclusion: Small variations in whole‑body hydration status alter different biomechanical properties of the cornea, with these changes being associated with intraocular pressure levels. These findings indicate that whole‑body hydration status can be considered for the diagnosis and management of different ocular conditions.

There is some controversy about the utility of prescribing blue-blocking filters to mitigate digital eye strain. We found that using commercially available blue-blocking filters was ineffective in reducing orbicularis oculi muscle activity and visual symptomatology during a 30-min reading task from a computer screen.There are some claims that blue-blocking (B-B) filters may be effective in reducing symptoms and signs of digital eye strain. However, recent studies have suggested that there is no sufficient evidence to support their use. This study assessed the short-term effects of a commercially available, B-B filter on orbicularis oculi (OO) muscle activity and symptoms of digital eye strain during the execution of a 30-min reading tas.Twenty-three healthy young adults (22.9 ± 3.2 years of age) performed two reading tasks from a computer screen with or without a B-B filter on two different days. OO muscle activity was recorded by surface electromyography 4-5, 9-10, 14-15, 19-20, 24-25 and 29-30 min into the trial. Participants reported their perceived levels of visual discomfort and activation before and after completing the reading task.A Bayesian analysis favoured the null hypothesis that there was no change in OO muscle activity with or without using the B-B filter (Bayes Factor01 [BF01] = 7.08). Regarding symptomatology, the analysis favoured the time model that reading increased visual fatigue and discomfort but reduced activation levels (BF01 0.33 in all cases). However, our data did not support the alternative model that using B-B filter affected these visual symptoms.The B-B filter did not alter OO muscle activity or visual symptomatology significantly during the execution of a 30-min reading task in asymptomatic subjects. These findings support the idea that B-B filters do not attenuate signs and symptoms of digital eye strain.

Introduction: Dual-focus soft contact lenses for myopia management have demonstrated to be an effective strategy to reduce myopia progression. However, this optical design has been shown to alter visual quality and accommodative function. The aim of this study was to examine the accommodative and behavioural performance during the execution of a psychomotor vigilance task (PVT) while wearing dual-focus and single-vision soft contact lenses. Methods: The steady-state accommodative response was recorded with the WAM-5500 binocular open-field autorefractor during the execution of a 10-min PVT at 50 cm either with the dual-focus (MiSight 1-day) or single-vision (Proclear 1-day) soft contact lenses, using a sample of 23 healthy young adults. Each experimental session was performed on two different days in a counterbalanced order. Results: A greater lag of accommodation, variability of accommodation and reaction time was found while wearing dual-focus in comparison with single-vision soft contact lenses (mean differences during the 10-min PVT were 0.58 ± 0.81 D, p < 0.001; 0.31 ± 0.17 D, p < 0.001 and 15.22 ± 20.93 ms, p = 0.002, respectively). Also, a time-on- task effect was found for the variability of accommodation and reaction time (p = 0.001 and p < 0.001, respectively), observing higher values over time. However, the lag of accommodation did not change significantly as a function of time-on- task (p = 0.33). Conclusion: Dual-focus soft contact lens wear influences the steady-state accommodative response and behavioural performance during the execution of a visual vigilance task in the short-term. Eye care practitioners should be aware of these effects when prescribing these lenses for myopia management, and provide specific recommendations according to the individual visual needs.

Alzheimer's disease and Type 2 diabetes are pathological processes associated to ageing. Moreover, there are evidences supporting a mechanistic link between Alzheimer's disease and insulin resistance (one of the first hallmarks of Type 2 diabetes). Regarding Alzheimer's disease, amyloid β-peptide aggregation into β-sheets is the main hallmark of Alzheimer's disease. At monomeric state, amyloid β-peptide is not toxic but its function in brain, if any, is unknown. Here we show, by in silico study, that monomeric amyloid β-peptide 1-40 shares the tertiary structure with insulin and is thereby able to bind and activate insulin receptor. We validated this prediction experimentally by treating human neuroblastoma cells with increasing concentrations of monomeric amyloid β-peptide 1-40. Our results confirm that monomeric amyloid β-peptide 1-40 activates insulin receptor autophosphorylation, triggering downstream enzyme phosphorylations and the glucose Transporter 4 translocation to the membrane. On the other hand, neuronal insulin resistance is known to be associated to Alzheimer's disease since early stages. We thus modelled the docking of oligomeric amyloid β-peptide 1-40 to insulin receptor. We found that oligomeric amyloid β-peptide 1-40 blocks insulin receptor, impairing its activation. It was confirmed in vitro by observing the lack of insulin receptor autophosphorylation, and also the impairment of insulin-induced intracellular enzyme activations and the glucose Transporter 4 translocation to the membrane. By biological system analysis, we have carried out a mathematical model recapitulating the process that turns amyloid β-peptide binding to insulin receptor from the physiological to the pathophysiological regime. Our results suggest that monomeric amyloid β-peptide 1-40 contributes to mimic insulin effects in the brain, which could be good when neurons have an extra requirement of energy beside the well-known protective effects on insulin intracellular signalling, while its accumulation and subsequent oligomerization blocks the insulin receptor producing insulin resistance and compromising neuronal metabolism and protective pathways. This work was supported by the Spanish Ministry of Science and Innovation and Agencia Estatal de Investigación plus European Regional Development Fund (FEDER Funds) through grants PID2020-117691RB-I00/AEI/10.13039/501100011033 (F.J.M.), SAF2017-83372-R (F.J.M.), BIO2017-85329-R (B.O.), PGC2018-101251-B-I00 (J.G.-O.) and RTI2018-094579-B-I00 (X.F.-B.). This work was also funded by the Spanish Institute of Health Carlos III by project reference AC20/00009 -FEDER/UE and European Research Era Net (ERANET) ERA-CVD_JTC2020-015 (J.G.-O.), by the ‘María de Maeztu Programme’ for Units of Excellence in Research and Development (R&D; award CEX2018-000792-M), Generalitat de Catalunya (Spain) through the grant 2017-SGR-908 (X.F.-B.) and Fundación QUAES through Cátedra QUAES-UPF de Biomedicina e Ingeniería Biomédica. The Instituto de Salud Global de Barcelona (ISGlobal) and Institute for Bioengineering of Catalonia (IBEC) are members of the Centres de Recerca de Catalunya (CERCA) Programme, Generalitat de Catalunya (Spain). We acknowledge support from the Spanish Ministry of Science, Innovation and Universities through the ‘Centro de Excelencia Severo Ochoa 2019–2023’ Programme (CEX2018-000806-S). This research is part of ISGlobal's Programme on the Molecular Mechanisms of Malaria, which is partially supported by the Fundación Ramón Areces. J.G.-O. also acknowledges support from the Institució Catalana de Recerca i Estudis Avançats (ICREA) Academia programme.

Purpose: Recent technological advances have permitted to objectively record the accommodative response while shifting between two different levels of accommodation. This study is aimed at examining the concurrent validity of a new objective method for the qualitative and quantitative assessment of binocular accommodative facility, which is named 2Q-AF test, in comparison to the ±2.00 DS lens flippers. Methods: Fifty-six individuals took part in this study (36 healthy young adults [24.4 ± 3.2 years] and 20 children [12.2 ± 0.4 years]). Participants randomly performed the 2Q-AF and the ±2.00 DS lens flipper tests. For the 2Q-AF test, a binocular open-field autorefractor was used to record the magnitude of accommodative response during a 60-sec period, while participants repeatedly changed fixation from a 5 m to a 40 cm chart when clarity of vision was achieved at each level. Due to the advantages of the proposed method, we have determined the number of cycles and the 2Q-AF score, with the latter also considering the accuracy of changes in accommodation. A standard procedure was followed for the ±2.00 DS flipper test. Results: Our data exhibited a moderate association between the number of cycles with the ±2.00 DS lens flippers and the number of cycles in the 2Q-AF test in the group of young adults (p = .005, r = 0.46 [0.15–0.68]) and children (p = .007, r = 0.58 [0.19–0.81]), whereas a stronger relationship was observed when considering the number of cycles with the ±2.00 DS lens flippers and the 2Q-AF score (young adults: p < .001, r = 0.83 [0.69–0.91]; and children: p < .001, r = 0.78 [0.52–0.91]). Conclusions: The current findings show that the 2Q-AF test is a valid method for accommodative facility assessment, as suggested by its good levels of reliability and validity. This method allows to examine the accommodative facility in qualitative terms and solve most of the limitations associated with the ±2.00 DS lens flipper test.

Clinical Relevance Background: Steady-state accommodation is frequently evaluated with open-field autorefractors; however there is no consensus regarding the optimal test duration. Our results allow us to standardise the procedure followed for the assessment of the steady-state accommodative response in clinical and laboratory settings and may be of great relevance in time-constrained situations. BACKGROUND The present study aims to determine the optimal recording time to assess the magnitude and variability of the accommodative response with a binocular open-field autorefractor. METHODS The steady-state accommodative response of 84 healthy undergraduate students was dynamically measured using the Grand Seiko WAM-5500 autorefractor at 500 cm, 40 cm and 20 cm for 90 s while participants maintained focus on a stationary target. We examined the reliability and level of agreement between four time intervals (the first 10-s, 30-s, 60-s and 90-s) at three accommodative demands (0.2D, 2.5D and 5D). RESULTS The magnitude of accommodation showed an excellent level of reliability (intraclass correlation coefficient [ICC]> 0.90) for the comparisons between the 90-s, 60-s and 30-s time intervals at the three viewing distances tested. However, when including the 10-s interval, there was a moderate reduction of the reliability indices and an increase of the mean difference between two time intervals (intra-class correlation [ICC] ranging from 0.89 to 0.97; and ESs ranging from 0.16 to 0.42). For the variability of accommodation, we observed an excellent reliability for the comparisons of the 90-s and 60-s measures at the three accommodative demands (ICC: 0.95-0.96), whereas for the rest of comparisons we observed from moderate to good levels of reliability. CONCLUSION Our data indicate that of 30-s and 60-s are enough to accurately assess the magnitude and variability of the accommodative response with the WAM-5500 autorefractor, respectively.

La Cuenca del Segura (Sureste de España) se caracteriza por una marcada escasez hídrica, lo que ha suscitado el frecuente uso de recursos hídricos no convencionales, como el agua marina desalinizada (AMD), para el riego y abastecimiento. El AMD, a pesar de su baja conductividad eléctrica comprendida entre 0,36 y 0,90 dS/m, se caracteriza por una elevada concentración de boro, cloruro y sodio. El boro, aun siendo un elemento esencial para los cultivos, se puede presentar en el AMD en una concentración tóxica y puede suponer un riesgo para las cosechas. Existen diversos métodos para la reducción y eliminación de boro en AMD, entre los que se encuentran las resinas de intercambio iónico (RII). La principal característica de una resina es su selectividad específica por un elemento, la cual está determinada por su composición química y estructura molecular. Gracias a esta selectividad, y de manera contraria a otros métodos como las membranas de ósmosis inversa, método más extendido en el mundo en la actualidad, la resina no produce un agua prácticamente desmineralizada. En este estudió se evaluó el efecto de un equipo de RII, con selectividad por el boro, en la reducción de dicho elemento en AMD, así como su coste y su eficiencia energética. Los resultados obtenidos indicaron que la resina empleada, Amberlite PWA10, eliminó el boro del AMD de forma eficaz, y mostró una elevada eficiencia desde el punto de vista energético. Sin embargo, el elevado coste de inversión del equipo y los costes operativos de mantenimiento pueden resultar su principal inconveniente.

The purpose of the present study was to assess the accommodative response and pupillary dynamics while reading passages with different text-background color combinations on an LCD screen. Twenty healthy young adults read fourteen 2-min passages designed with fourteen different color combinations between text and background, while the accommodative and pupil responses were continuously measured with a binocular open-field autorefractometer. Our results revealed that the text-background color combination modulates the accommodative and pupillary dynamics during a 2-minutes reading task. The blue-red combination induced a heightened accommodative response, whereas positive polarities were associated with more variability of the accommodative response and smaller pupil sizes. Participants reported lower perceived ratings of legibility for text-background color combination with lower luminance contrast (white-yellow). The manipulation of text-background color did not have a significant effect on reading speed. These results may have important applications in the design of digital visual interfaces.

Introducción El desgarro muscular agudo es el tipo de lesión más frecuente en actividades deportivas. Se ha tomado interés en busca de modalidades que reduzcan y mejoren el tiempo de curación. El uso de plasma rico en plaquetas (PRP) ha crecido en popularidad en los últimos años, pero dicha popularidad no fue acompañada de suficiente respaldo científico que avale su eficacia. Este estudio intenta recabar, analizar y sintetizar la información publicada para esclarecer los efectos del uso de PRP en desgarros musculares agudos mediante revisión sistemática y meta-análisis. Material y Métodos Se realizó una revisión sistemática de la literatura sobre el uso de PRP para el tratamiento de las lesiones musculares agudas. Un metanálisis fue conducido para evaluar los efectos del PRP. Resultados Siete artículos cumplieron los criterios de inclusión. Seis ensayos controlados aleatorizados y un estudio de cohorte. El tiempo total de retorno al deporte con PRP fue de una media de 29 días (rango, 10 a 50.9 días). En los grupos control fue una media de 35,4 días (rango, 22 a 52,8 días). El metanálisis demostró una diferencia significativa en el retorno deportivo con el uso de PRP en comparación con la terapia convencional (-7.80 días; p = 0.007). No se informaron diferencias en la tasa de recurrencia. Conclusión El metanálisis demostró un efecto favorable de PRP en comparación con la terapia convencional. Sin embargo, nuestro análisis demostró una heterogeneidad significativa en el estudio. Los resultados deben interpretarse con cautela. Aún no podemos recomendar el uso de PRP para el tratamiento de desgarros musculares agudos.