32 research outputs found

    Potential use of Sargassum muticum as source of plant biostimulants after three different drying methods

    Get PDF
    Seaweed derived biostimulants are gaining attention as an important tool in sustainable agriculture. This offers a unique opportunity to alleviate the environmental impact of Sargassum muticum (Ochrophyta, Phaeophyceae) as an invasive species by finding new applications for its biomass. In this sense, incorporating green extraction technologies is fundamental to ensure environmental-friendly goals. This research was initiated in an attempt to contribute to an integral valorization system of S. muticum biomass, exploring the biostimulant potential of the solubles obtained from pressed solids, through an autohydrolysis treatment. In addition, we compared the effect of three different liquid phase drying techniques (spray-drying, freeze-drying and convective air-drying). Low stress drying techniques as spray-drying showed better conservation of bioactive compounds and biostimulant potential. A bioassay with Nastrium officinale showed no phytotoxic effects despite high electric conductivity in most of the extracts and concentrations. Dried extracts showed mainly an amorphous structure but occasional crystal formation when spray-dried at low temperatures (T out  = 50 ºC) and after convective air drying (T = 40 ºC). Significant increases in root development were achieved at a concentration of 5 mg L −1 of spray-dried extracts and 50 mg L −1 in case of freeze-dried extracts. Munoo-Liisa vitality index showed best results with 50 mg L −1 of freeze-dried extracts. This study provides important information about the influence of different drying techniques on the physicochemical properties and biostimulant potential of S. muticum aqueous extracts and contributes to the integral valorization of its biomass.Agencia Estatal de Investigación | Ref. RYC2018-024454-IXunta de Galicia | Ref. ED431F 2020/01Xunta de Galicia | Ref. ED481D-2022/018Universidade de Vigo/CISU

    Early functional and morphological muscle adaptations during short-term inertial-squat training

    Get PDF
    Purpose: To assess early changes in muscle function and hypertrophy, measured as increases in muscle cross-sectional areas (CSAs) and total volume, over a 4 weeks inertial resistance training (RT) program. Methods: Ten young RT-naive volunteers (age 23.4 4.1 years) underwent 10 training sessions (2-3 per week) consisting of five sets of 10 flywheel squats (moment of inertia 900 kg cm2). Magnetic resonance imaging (MRI) scans of both thighs were performed before (PRE), and after 2 (IN) and 4 (POST) weeks of training to compute individual muscle volumes and regional CSAs. Scans were performed after 96 h of recovery after training sessions, to avoid any influence of acute muscle swelling. PRE and POST regional muscle activation was assessed using muscle functional MRI (mfMRI) scans. Concentric (CON) and eccentric (ECC) squat force and power, as well as maximal voluntary isometric contraction force (MVIC) of knee extensors and flexors, were measured in every training session. Results: Significant quadriceps hypertrophy was detected during (IN: 5.5% 1.9%) and after (POST: 8.6% 3.6%) the training program. Increases in squat force (CON: 32% 15%, ECC: 31 15%) and power (CON: 51% 30%, ECC: 48% 27%) were observed over the training program. Knee extensor MVIC significantly increased 28% 17% after training, but no changes were seen in knee flexor MVIC. No correlation was found between regional muscular activation in the first session and the % of increase in regional CSAs (r = -0.043, P = 0.164). Conclusion: This study reports the earliest onset of whole-muscle hypertrophy documented to date. The process initiates early and continues in response to RT, contributing to initial increases in force. The results call into question the reliability of mfMRI as a tool for predicting the potential hypertrophic effects of a given strengthening exercise

    Validity of a low-cost friction encoder for measuring velocity, force and power in flywheel exercise devices

    Get PDF
    The purpose of this study was to investigate the validity of a low-cost friction encoder against a criterion measure (strain gauge combined with a linear encoder) for assessing velocity, force and power in flywheel exercise devices. Ten young and physically active volunteers performed two sets of 14 maximal squats on a flywheel inertial device (YoYo Technology, Stockholm, Sweden) with five minutes rest between each set. Two different resistances were used (0.075 kg · m2 for the first set; 0.025 kg · m2 for the second). Mean velocity (Vrep), force (Frep) and power (Prep) for each repetition were assessed simultaneously via a friction encoder (Chronojump, Barcelona, Spain), and with a strain gauge combined with a linear encoder (MuscleLab 6000, Ergotest Technology, Porsgrunn, Norway). Results are displayed as (Mean [CI 90%]). Compared to criterion measures, mean bias for the practical measures of Vrep, Frep and Prep were moderate (-0.95 [-0.99 to -0.92]), small (0.53 [0.50 to 0.56]) and moderate (-0.68 [-0.71 to -0.65]) respectively. The typical error of estimate (TEE) was small for all three parameters; Vrep (0.23 [0.20 to 0.25]), Frep (0.20 [0.18 to 0.22]) and Prep (0.18 [0.16 to 0.20]). Correlations with MuscleLab were nearly perfect for all measures in all load configurations. Based on these findings, the friction encoder provides valid measures of velocity, force and power in flywheel exercise devices. However, as error did exist between measures, the same testing protocol should be used when assessing changes in these parameters over time, or when aiming to perform inter-individual comparisons

    Early Functional and Morphological Muscle Adaptations During Short-Term Inertial-Squat Training

    Get PDF
    Purpose: To assess early changes in muscle function and hypertrophy, measured as increases in muscle cross-sectional areas (CSAs) and total volume, over a 4 weeks inertial resistance training (RT) program.Methods: Ten young RT-naive volunteers (age 23.4 ± 4.1 years) underwent 10 training sessions (2–3 per week) consisting of five sets of 10 flywheel squats (moment of inertia 900 kg⋅cm2). Magnetic resonance imaging (MRI) scans of both thighs were performed before (PRE), and after 2 (IN) and 4 (POST) weeks of training to compute individual muscle volumes and regional CSAs. Scans were performed after ≥96 h of recovery after training sessions, to avoid any influence of acute muscle swelling. PRE and POST regional muscle activation was assessed using muscle functional MRI (mfMRI) scans. Concentric (CON) and eccentric (ECC) squat force and power, as well as maximal voluntary isometric contraction force (MVIC) of knee extensors and flexors, were measured in every training session.Results: Significant quadriceps hypertrophy was detected during (IN: 5.5% ± 1.9%) and after (POST: 8.6% ± 3.6%) the training program. Increases in squat force (CON: 32% ± 15%, ECC: 31 ± 15%) and power (CON: 51% ± 30%, ECC: 48% ± 27%) were observed over the training program. Knee extensor MVIC significantly increased 28% ± 17% after training, but no changes were seen in knee flexor MVIC. No correlation was found between regional muscular activation in the first session and the % of increase in regional CSAs (r = -0.043, P = 0.164).Conclusion: This study reports the earliest onset of whole-muscle hypertrophy documented to date. The process initiates early and continues in response to RT, contributing to initial increases in force. The results call into question the reliability of mfMRI as a tool for predicting the potential hypertrophic effects of a given strengthening exercise

    The Influence of Functional Flywheel Resistance Training on Movement Variability and Movement Velocity in Elite Rugby Players

    Get PDF
    The aim of this study was to identify the changes in movement variability and movement velocity during a six-week training period using a resistance horizontal forward–backward task without (NOBALL) or with (BALL) the constraint of catching and throwing a rugby ball in the forward phase. Eleven elite male rugby union players (mean ± SD: age 25.5 ± 2.0 years, height 1.83 ± 0.06 m, body mass 95 ± 18 kg, rugby practice 14 ± 3 years) performed eight repetitions of NOBALL and BALL conditions once a week in a rotational flywheel device. Velocity was recorded by an attached rotary encoder while acceleration data were used to calculate sample entropy (SampEn), multiscale entropy, and the complexity index. SampEn showed no significant decrease for NOBALL (ES = -0.64 ± 1.02) and significant decrease for BALL (ES = -1.71 ± 1.16; p < 0.007) conditions. Additionally, movement velocity showed a significant increase for NOBALL (ES = 1.02 ± 1.05; p < 0.047) and significant increase for BALL (ES = 1.25 ± 1.08; p < 0.025) between weeks 1 and 6. The complexity index showed higher levels of complexity in the BALL condition, specifically in the first three weeks. Movement velocity and complex dynamics were adapted to the constraints of the task after a four-week training period. Entropy measures seem a promising processing signal technique to identify when these exercise tasks should be changed

    How the analysis of archival data could provide helpful information about TID degradation. Case study: Bipolar transistors

    Get PDF
    A critical step of radiation hardness assurance (RHA) for space systems is given by the parts selection in accordance with the observed (or estimated) radiation effects. Although radiation testing is the most decisive way of studying the radiation degradation of electronic components, the increasing use of commercial off-the-shelf (COTS) devices and the challenges posed by NewSpace are pushing the need of finding new approaches to assess the risk associated with radiation environments. This work tries to evaluate if valuable information might be extracted from archival data to carry out this assessment despite the well-known and dramatic lot-to-lot, or even part-to-part, variability for some technologies and the impact of the different test conditions, such as the bias conditions and the dose rate in enhanced low dose rate sensitivity (ELDRS). These factors are briefly analyzed for some examples. A new radiation database is briefly introduced, and some statistical approaches are cited, apart from the analysis herein followed. To finish, a first analysis on three families of bipolar transistors is presented together with the independent results from three external reports, with a good agreement between the experimental results and the expected ones.10.13039/501100002878-Junta de Andalucia and Fondo Europeo de Desarrollo Regional (FEDER) Funds through the Singular Project Predicción del Comportamiento Eléctrico de Dispositivos Electrónicos bajo Radiación (PRECEDER) (Grant Number: CEI-5-RNM138). 10.13039/501100004837-Spanish Ministry of Science and Innovation under Project (Grant Number: PID2019-108377RB-C32)Peer reviewe

    Unpaid extinction debts for endemic plants and invertebrates as a legacy of habitat loss on oceanic islands

    Get PDF
    Aim: The majority of documented extinctions world-wide in the last four centuries are of species endemic to islands. However, the phenomenon of delayed extinctions as a result of habitat loss has rarely been assessed on oceanic islands. In this study, we tested whether extinction debt (ED), in general, occurs on islands and for which taxonomical groups this phenomenon is most pronounced by assessing ED for multiple endemic taxa and for each of the main altitudinal ecosystems in a well-studied oceanic archipelago. Location: Canary Islands. Methods: We characterized habitat preferences for all endemic species of several taxonomic groups (vascular plants, ground and darkling beetles, flies and land snails). Using generalized linear mixed models and available data about habitat distributions, we tested for all taxa and habitat types to determine whether past habitat area better explained current richness of habitat specialists than current habitat area. If so, an extinction debt can be assumed. Results: For all five major habitat types and five taxonomic groups studied, present-day richness of habitat specialists fitted better with past than current habitat area, evidencing habitat-and taxon-specific extinction debts. This pattern was consistent for both long-lived vascular plants and short-lived invertebrates. Single island endemics in each taxonomic group showed steeper slopes of the species–area relationship (SAR) compared to archipelago endemics indicating higher sensitivity to habitat loss which might increase sizes of ED. Conclusion: Despite differences in species’ generation times, plants and invertebrates showed delayed extinctions after habitat destruction in the Canary Islands. Our SAR approach suggests that a considerable number of Canary Island endemics will eventually become extinct in the future without further habitat loss. The case of the Canary archipelago is probably not unique. Hence, we interpret our results as a warning for island conservationists that the worst of the extinction crisis on oceanic islands might be yet to come. Conservation actions should focus on habitat restoration to attenuate or reverse current extinction processes.Universidad de Las Palmas de Gran CanariaUniversidad de La Lagun

    Efectos del ejercicio terapéutico sobre la musculatura del tobillo y la musculatura intrínseca del pie en pacientes con inestabilidad crónica de tobillo. Revisión sistemática

    Get PDF
    Introducción: La inestabilidad crónica de tobillo (ICT) es una de las patologías más comunes en el ámbito deportivo. Es una condición multifactorial que cursa con síntomas persistentes de inestabilidad percibida y/o inestabilidad mecánica que suelen venir asociados a esguinces recurrentes de tobillo. La mayor parte de pacientes se podrían beneficiar del ejercicio terapéutico, evitando así la cirugía. Existe literatura reciente de ensayos clínicos que estudian los efectos del entrenamiento de la musculatura intrínseca del pie (MIP) y/o del entrenamiento de la musculatura movilizadora del tobillo (MMT) en estos pacientes. Objetivos: El objetivo de esta revisión fue determinar los efectos del entrenamiento de la MIP y/o del entrenamiento de la MMT en la capacidad funcional, el equilibrio estático, el equilibrio dinámico, la inestabilidad, el rango de movimiento (ROM) y la fuerza en pacientes con ICT. Metodología: Se realizó una revisión sistemática con búsquedas en las bases de datos Medline, Cochrane Library, PEDro, WOS y Scopus. Se seleccionaron ensayos clínicos aleatorizados que analizaran los efectos del entrenamiento de la MIP y/o del entrenamiento de la MMT en la capacidad funcional, el equilibrio estático, el equilibrio dinámico, la inestabilidad, el ROM y/o la fuerza en sujetos con ICT. Resultados: Diez estudios cumplieron los criterios de inclusión. El entrenamiento de la MIP mejoró el equilibrio dinámico, la inestabilidad y el ROM de eversión. El entrenamiento de la MMT mejoró el equilibrio y la fuerza de tobillo. Conclusión: El entrenamiento de la MIP ha mostrado beneficios a corto plazo en el equilibrio dinámico, la inestabilidad y el ROM de eversión en pacientes con ICT. El entrenamiento de la MMT ha demostrado mejorar el equilibrio y la fuerza de tobillo a corto plazo en pacientes con ICT.Grado en Fisioterapi

    Diseño para Parmac Solutions de un modelo de gestión administrativa fundamentado en el modelo de gestión de calidad

    Get PDF
    Trabajo de grado (Administrador de Empresas)-- Universidad Autónoma de Occidente, 2010PregradoAdministrador(a) de Empresa
    corecore