84 research outputs found
Mechanical Thinning of Mandarins with a Branch Shaker
[EN] Thinning is the process of removing some flowers or fruit to increase fruit size at harvest. In the Valencia region of Spain, the thinning operation for citrus fruit (Citreae) is performed for some mandarin varieties. This is always performed manually; however, this method is very expensive. The goal of this research study was to assess the mechanical thinning of mandarin ( Citrus reticulata) using a hand-held branch shaker. Different thinning treatments were conducted over a 3-year period. The gasoline-powered branch shaker was capable of detaching fruit four- to five-times faster than manual thinning. Final fruit size was significantly higher using manual and mechanical thinning compared with a no thinning treatment. Similar final fruit size was obtained with manual and mechanical thinning. However, no significant differences were found in final fruit yield by weight among no thinning, mechanical thinning, and manual thinning treatments. The use of a branch shaker could be recommended for thinning operations to increase efficiency, reduce labor costs, and obtain larger and higher-quality fruit.This work was supported by funding from the Instituto Nacional de Investigaciones Agrarias (INIA) and European FEDER (Project RTA2014-00025-C05-02). Fontestat provided the experimental fields.Ortiz Sánchez, MC.; Torregrosa, A.; Ortí García, E.; Balasch Parisi, S. (2020). Mechanical Thinning of Mandarins with a Branch Shaker. HortTechnology. 30(6):745-750. https://doi.org/10.21273/HORTTECH04451-20S74575030
Solución de múltiples sistemas lineales en GPUs
Este trabajo se centra en el calculo, de forma concurrente, de múltiples sistemas lineales definidos por matrices densas de una dimensión media. Se considera una solución basada en la factorización de Cholesky y su implementación sobre plataformas GPUs. Este tipo de problema algebraico forma parte de distintos modelos de procesamiento de señal, y además exhibe distintos niveles de paralelismo que pueden ser explotados muy eficientemente por las GPUs. En este trabajo, como aplicación del problema, nos centramos en la detección de anomalías sobre imágenes hiperespectrales, lo que supone una importante tarea en la explotación de este tipo de imágenes obtenidas en la observación de la Tierra. Concretamente, consideramos la versión local del ampliamente usado algoritmo RX (Reed-Xiaoli), denotado como LRX, en el que una de sus etapas más costosas consiste en la solución, para cada pixel de la imagen, de un sistema lineal cuyas dimensiones coinciden con el número de bandas de la imagen. En este contexto se describe y evalúa la solución múltiple de sistemas lineales en GPUs, y se comprueba el factor de aceleración obtenido con la implementación propuesta en este trabajo.Este trabajo ha sido financiado por el Ministerio
de Economía y Competitividad (TIN2008-
01117, TIN2011-23283, TIN2012-37483-C03-01 and
AYA2011-29334-C02-02), Junta de Andalucía (P10-
TIC-6002 y P011-TIC7176), Junta de Extremadura
(PRI09A110 y GR10035), CAPAP-H4 (TIN2011-
15734-E) y por los fondos FEDER. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
Preliminary evaluation of a blast sprayer controlled by pulse width modulated nozzles
[EN] Precision spraying relies on the response of the spraying equipment to the features of the targeted canopy. PWM technology manages the flow rate using a set of electronically actuated solenoid valves to regulate flow rate at the nozzle level. Previous studies have found that PWM systems may deliver incorrect flow rates. The objective of the present study was to characterize the performance of a commercial blast sprayer modified with pulse-width-modulated nozzles under laboratory conditions, as a preliminary step before its further field validation. Four different duty cycles (25 percent, 50 percent, 75 percent and 100 percent) and four different pressures (400 kPa, 500 kPa, 600 kPa and 700 kPa) were combined to experimentally measure the flow rate of each nozzle. Results showed that the PWM nozzles mounted in the commercial blast sprayer, under static conditions, were capable of modulating flow rate according to the duty cycle. However, the reduction of flow rates for the tested duty cycles according to pressure was lower than the percentage expected. A good linear relation was found between the pressure registered by the control system feedback sensor and the pressure measured by a reference conventional manometer located after the pump. High-speed video recordings confirmed the accurate opening and closing of the nozzles according to the duty cycle; however, substantial pressure variations were found at nozzle level. Further research to establish the general suitability of PWM systems for regulating nozzle flow rates in blast sprayers without modifying the system pressure still remains to be addressed.This research was funded by the Government of Spain through the project "Smart spraying for a sustainable vineyard and olive trees" PIVOS (PID2019-104289RB).Ortí García, E.; Cuenca, A.; Pérez Teruel, M.; Torregrosa, A.; Ortiz Sánchez, MC.; Rovira Más, F. (2022). Preliminary evaluation of a blast sprayer controlled by pulse width modulated nozzles. Sensors. 22(13):1-12. https://doi.org/10.3390/s22134924112221
Spin-Crossover Grafted Monolayer of a Co(II) Terpyridine Derivative Functionalized with Carboxylic Acid Groups
The synthesis and characterization of a new Co(II) spin-crossover (SCO) complex based on 4′-(4-carboxyphenyl)−2,2′:6′,2″-terpyridine ligand are reported. This complex can be successfully grafted on silver surface maintaining the SCO behavior. Thus, atomic force microscopy (AFM), matrix assisted laser desorption ionization - time-of-flight mass spectrometry (MALDI-TOF MS), Raman spectroscopy, and XPS measurements, upon surface deposition, evidence the formation of a monolayer of intact molecules grafted through carboxylate groups to the Ag surface. Three different techniques: Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS), supported by first-principles calculations, confirm that the deposited molecules undergo a gradual spin transition with temperature. This phenomenon is unprecedented for a monolayer of molecules directly grafted onto a metallic surface from solution
Experimental learning and virtual reality for teaching with High-Capacity students, an interuniversity experience in the degrees of education
Esta investigación tiene como objetivo comprender las opiniones y las experiencias de los estudiantes de magisterio sobre sus competencias para trabajar con alumnos con altas capacidades a través de la realidad virtual y el aprendizaje experimental. Metodológicamente la investigación conserva un diseño descriptivo cuantitativo, puesto que se realiza un test y post-test antes y después del proyecto de innovación, combinado con aspectos cualitativos derivados de la realización de entrevistas. Se cuenta con una muestra de cien estudiantes de magisterio de Turquía, Grecia y España. Los resultados ayudan a conocer las diferentes maneras de clasificar a los estudiantes con altas capacidades, lo que conlleva diversidad de planes y principios metodológicos según los países donde los discentes se están formando. Los futuros maestros manifiestan tener una baja competencia en el uso educativo de las herramientas de realidad virtual, pese a ello, indican que el binomio que conforma el aprendizaje experimental y la realidad virtual ha sido una metodología muy positiva para mejorar sus competencias. El haber realizado un nuevo plan de estudios basado en la teoría del aprendizaje experimental para la formación de profesores, supone un avance significativo en la formación de los futuros docentes para trabajar con niños superdotados y talentosos.This research aims to understand the opinions and experiences of students in education degrees about their skills to work with high-capacity students through virtual reality and experiential learning. Methodologically, the research maintains a quantitative descriptive design, since a test and post-test are carried out before the training, combined with qualitative aspects through interviews. There is a sample of one hundred university students from Turkey, Greece and Spain. The results help to know the different ways of classifying students with high abilities, which entails a diversity of plans, strategies and methodological principles according to the countries where the students are being trained. As for the future teachers, they state that they have low competence in the educational use of virtual reality tools, despite this, thestudents indicate that the binomial that makes up experimental learning and virtual reality has been a very positive methodology for improving their skills to work with students. The conclusions point to the fact that having carried out a new reference curriculum based on the theory of experimental learning, which makes use of virtual reality resources to be used in the training of teachers, seems to be a significant advance in the training of early Childhood and Primary Education future teachers
Reply to “When Is a Ketogenic Diet Ketogenic? Comment on Satiating Effect of a Ketogenic Diet and Its Impact on Muscle Improvement and Oxidation State in Multiple Sclerosis Patients. Nutrients 2019, 11, 1156”
Planarity vs. Non-Planarity in the Electronic Communication of TCAQ-Based Push-Pull Chromophores
Donor-acceptor alkynes, endowed with 11,11,12,12-tetracyano-9,10-anthraquinodimethane (TCAQ) and N,N-dimethylaniline (DMA) units, have been further functionalized by a [2+2] tetracyanoethylene (TCNE) cycloaddition followed by a subsequent retroelectrocyclization to form distorted non-planar molecular structures with 1,1,4,4-tetracyanobuta-1,3-diene (TCBD) bridge ligands. Comprehensive spectroscopic, electrochemical, and computational studies have been carried out to compare the electronic communication in these planar (alkyne) and nonplanar (with TCBD units) TCAQ-based push-pull chromophores. Cyclic voltammetry and UV-Vis absorption measurements confirm a noticeable electronic communication between the TCAQ and DMA units regardless the quasi-orthogonal arrangement of the two dicyanovinyl halves of the TCBD groups, which partially hinder the electronic communication. The experimental trends are strongly supported by theoretical calculations performed at the density functional theory level, which further evidence an active electron-withdrawing role of the TCBD bridge both in the formation of the charged species and in the lowest-lying absorption features. The novel push-pull TCAQ-based derivatives including the TCBD bridge show a broad absorption in the whole visible range while having a structure highly distorted from planarity. These chromophores may therefore be viewed as appealing candidates to be exploited in photovoltaic devices with minimal aggregation phenomena
Poor Bone Quality in Patients With Amyotrophic Lateral Sclerosis
Objective: Musculoskeletal functional deterioration in Amyotrophic lateral sclerosis (ALS) is associated with an increase in bone fractures. The purpose of this study was to evaluate the influence of sex, ALS type, on bone quality in patients with ALS compared to healthy controls. The impact on bone health of the clinical status and some metabolic parameters was also analyzed in ALS patients. Methods: A series of 33 voluntary patients with ALS, and 66 healthy individuals matched in sex and age underwent assessment of bone mass quality using quantitative ultrasound (QUS) of the calcaneus. Ultrasonic broadband attenuation (BUA), the speed of sound (SOS), stiffness index and T-score were measured. Bone mineral density (BMD) was estimated using standard equations. Apart from fat and muscle mass percentage determinations, clinical baseline measures in ALS patients included ALSFRS-R score, Barthel index for activities of daily living, pulmonary function measured using FVC, and muscular strength assessed by a modified MRC grading scale. Laboratory tests included serum calcium, 25-HO-cholecalciferol (Vitamin D), alkaline phosphatase (ALP), T4 and TSH. Results: All bone parameters evaluated were statistically significant lower in ALS patients than in healthy controls. ALS females showed significantly lower bone parameters than healthy females. According to the estimated BMD, there were 25 ALS patients (75.8%) and 36 (54.5%) healthy individuals showing an osteoporotic profile (BMD <0.700 g/cm2). Only 16.7% of the ALS females had T-scores indicative of healthy bones. There was no correlation between any of the clinical parameters analyzed and the bone QUS measurements. Vitamin D and TSH levels positively correlated with all the bone parameters. Conclusions: This study confirms that ALS patients, particularly females, exhibited deteriorated bone health as compared to healthy individuals. These structural bone changes were independent of ALS subtype and clinical status. Bone health in ALS patients seems to be related to certain metabolic parameters such as Vitamin D and TSH levels
The Impact of Microbiota on the Pathogenesis of Amyotrophic Lateral Sclerosis and the Possible Benefits of Polyphenols. An Overview
The relationship between gut microbiota and neurodegenerative diseases is becoming
clearer. Among said diseases amyotrophic lateral sclerosis (ALS) stands out due to its severity
and, as with other chronic pathologies that cause neurodegeneration, gut microbiota could play a
fundamental role in its pathogenesis. Therefore, polyphenols could be a therapeutic alternative due
to their anti-inflammatory action and probiotic effect. Thus, the objective of our narrative review
was to identify those bacteria that could have connection with the mentioned disease (ALS) and to
analyze the benefits produced by administering polyphenols. Therefore, an extensive search was
carried out selecting the most relevant articles published between 2005 and 2020 on the PubMed and
EBSCO database on research carried out on cell, animal and human models of the disease. Thereby,
after selecting, analyzing and debating the main articles on this topic, the bacteria related to the
pathogenesis of ALS have been identified, among which we can positively highlight the presence
mainly of Akkermansia muciniphila, but also Lactobacillus spp., Bifidobacterium spp. or Butyrivibrio
fibrisolvens. Nevertheless, the presence of Escherichia coli or Ruminococcus torques stand out negatively
for the disease. In addition, most of these bacteria are associated with molecular changes also linked
to the pathogenesis of ALS. However, once the main polyphenols related to improvements in any of
these three ALS models were assessed, many of them show positive results that could improve the
prognosis of the disease. Nonetheless, epigallocatechin gallate (EGCG), curcumin and resveratrol are
the polyphenols considered to show the most promising results as a therapeutic alternative for ALS
through changes in microbiota.This study was funded by the Valencia Catholic University San Vicente Mártir (grant 2017-216-001).Medicin
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