Evaluation of the Cell Concentration in Suspensions of Human Leukocytes by Ultrasound Imaging: The Influence of Size Dispersion and Cell Type.

This work focuses on the use of ultrasound imaging to evaluate the cell concentration of dilute leukocyte suspensions in the range of 10-3000 cells/µL. First, numerical simulations were used to study the influence of the size dispersion and the leukocyte type on the performance of the concentration estimation algorithms, which were developed in previous works assuming single-sized scatterers. From this analysis, corrections to the mentioned algorithms were proposed and then the performance of these corrections was evaluated from experiments. For this, ultrasound images were captured from suspensions of lymphocytes, granulocytes, and their mixtures. These images were obtained using a 20 MHz single-channel scanning system. Results confirmed that concentration estimates provided by conventional algorithms were affected by the size dispersion of cells, leading to a remarkable underestimation of results. The proposed correction to compensate for cell size dispersion obtained from simulations improved the concentration estimation of these algorithms, for the cell suspensions tested, approaching the results to the reference optical characterization. Moreover, it was shown that these models provided a total leukocyte concentration from the ultrasound images which was independent of the relative populations of different white blood cell types.

Methodology for the Generation of High-Quality Ultrasonic Images of Complex Geometry Pieces Using Industrial Robots.

Industrial robotic arms integrated with server computers, sensors and actuators have revolutionized the way automated non-destructive testing is performed in the aeronautical sector. Currently, there are commercial, industrial robots that have the precision, speed and repetitiveness in their movements that make them suitable for use in numerous non-destructive testing inspections. Automatic ultrasonic inspection of complex geometry parts remains one of the most difficult challenges in the market. The closed configuration, i.e., restricted access to internal motion parameters, of these robotic arms makes it difficult for an adequate synchronism between the movement of the robot and the acquisition of the data. This is a serious problem in the inspection of aerospace components, where high-quality images are necessary to assess the condition of the inspected component. In this paper, we applied a methodology recently patented for the generation of high-quality ultrasonic images of complex geometry pieces using industrial robots. The methodology is based on the calculation of a synchronism map after a calibration experiment and to introduce this corrected map in an autonomous, independent external system developed by the authors to obtain precise ultrasonic images. Therefore, it has been shown that it is possible to establish the synchronization of any industrial robot with any ultrasonic imaging generation system to generate high-quality ultrasonic images.

Static Postural Control during Single-Leg Stance in Endurance, Team and Combat Athletes from the Spanish National Sport Technification Program.

In the context of pediatric physical exercise, the analysis of factors affecting postural control (PC) provides insight into the development of sport-specific motor skills. This study aims to evaluate the static PC during single-leg stance in endurance, team and combat athletes from the Spanish National Sport Technification Program. A total of 29 boys and 32 girls, aged 12 to 16 years old, were recruited. Centre of pressure (CoP) was measured on a force platform in standing position for 40 s under two sensorial and leg dominance conditions. Girls showed lower MVeloc (p < 0.001), MFreq (p > 0.001) and Sway (p < 0.001) values than boys in both sensorial conditions (open and closed eyes). The highest values in all PC variables were observed with eyes closed in both genders (p < 0.001). Sway values were lower in boys combat-athletes compared to endurance athletes in two sensorial conditions and with non-dominant leg (p < 0.05). Young athletes in their teens enrolled in a Sport Technification Program have shown differences in PC when comparing different visual conditions, sport disciplines and gender. This study opens a window to a better understanding of the determinants of PC during single-leg stance as a critical element in the sport specialization of young athletes.

The role of culture on 2020 SARS-CoV-2 Country deaths: a pandemic management based on cultural dimensions.

This study aims to analyze the role of cross-cultural country differences during a global pandemic. Based on country cultural dimensions and country economic indicators, the research proposes specific policies that might prove of value in order to manage and better respond to present and future critical events such as the 2020 SARS-CoV-2 outbreak. The methodology is based on multivariate analysis for the first set of countries and cross-country comparative analysis for the second set of countries. Research results reveal the critical role of the cultural dimensions individualism, power distance, masculinity, long-term orientation and indulgence, along with the country economic context in the magnitude of the consequences of a global pandemic within a country specific context. Based on these results, the study proposes policies adjusted to the countries specific cultural and economic frameworks in order to promote the most effective and efficient management of a critical event such as a global pandemic.

Estimation of the concentration of particles in suspension based on envelope statistics of ultrasound backscattering.

This work deals with the development of a methodology to evaluate the concentration in cell or particle suspensions from ultrasound images. The novelty of the method is based on two goals: first, it should be valid when the energy reaching the scatterers is unknown and cannot be measured or calibrated. In addition, it should be robust against echo overlap which may occur due to high scatterer concentration. Both characteristics are especially valuable in quantitative ultrasound analysis in the clinical context. In this regard, the present work considers the ability of envelope statistics models to characterize ultrasound images. Envelope statistical analysis are based on the examination of the physical properties of a medium through the study of the statistical distribution of the backscattered signal envelop. A review of the statistical distributions typically used to characterize scattering mediums was conducted. The main parameters of the distribution were estimated from simulations of signals backscattered by particle suspensions. Then, the ability of these parameters to characterize the suspension concentration was analyzed and the µ parameter from the Homodyned-K distribution resulted as the most suitable parameter for the task. Simulations were also used to study the impact of noise, signal amplitude variability and dispersion of particle sizes on the estimation method. The efficiency of the algorithm on experimental measurements was also evaluated. To this end, two sets of ultrasound images were obtained from suspensions of 7 µm and 12 µm polystyrene particles in water, using a 20 MHz focused transducer. The methodology proved to be efficient to quantify the concentration of particle suspensions in the range between 5 and 3000 particles/µl, achieving similar results for both particle sizes and for different signal-to-noise ratios.

Effects of Algae Meal Supplementation in Feedlot Lambs with Competent Reticular Groove Reflex on Growth Performance, Carcass Traits and Meat Characteristics.

There is growing interest in increasing omega-3 fatty acid (FA) contents in ruminant meat by means of dietary manipulation, but the effects of such manipulation on productive results and meat quality need to be ascertained. The aim of the present study was to assess the effects of supplementing lambs with competent reticular groove reflex (RGR) with marine algae as a source of omega-3 fatty acids on growth performance, carcass traits, and meat quality characteristics. Forty-eight feedlot lambs were distributed into three equal groups: the control group neither consumed marine algae nor had competent RGR, the second group received daily 2.5% of algae meal mixed in the concentrate, and the last group consumed the same amount of algae meal, but emulsified in a milk replacer and bottle-fed. Lambs in the second and third groups had competent RGR. There were not any negative effects on performance, carcass or meat quality parameters with algae supplementation. However, the results of the oxidative stability parameters were not conclusive. Ageing for 6 days improved meat tenderness and color, and increased lipid oxidation. In conclusion, algae meal inclusion in the diet of fattening lambs with competent RGR has no detrimental effects on animal performance, carcass traits or meat quality characteristics.

The Impact of COVID-19 on Sport in Twitter: A Quantitative and Qualitative Content Analysis.

The spread of the SARS-CoV-2 virus has transformed many aspects of people's daily life, including sports. Social networks have been flooded on these issues. The present study aims to analyze the tweets produced relating to sports and COVID-19. From the end of January to the beginning of May 2020, over 4,000,000 tweets on this subject were downloaded through the Twitter search API. Once the duplicates, replicas, and retweets were removed, 119,253 original tweets were analyzed. A quantitative-qualitative content analysis was used to study the selected tweets. Posts dynamics regarding sport and exercise evolved according to the COVID-19 pandemic and subsequent lockdown, shifting from considering sport as a healthy bastion to an activity exposed to disease like any other. Most media professional sporting events received great attention on Twitter, while grassroots and women's sport were relegated to a residual role. The analysis of the 30 topics identified focused on the social, sporting, economic and health impact of the pandemic on the sport. Sporting cancellations, leisure time and socialization disruptions, club bankruptcies, sports training and athletes' uncertain career development were the main concerns. Although general health measures appeared in the tweets analyzed, those addressed to sports practice were relatively scarce. Finally, this study shows the importance of Twitter as a means of conveying social attitudes towards sports and COVID-19 and its potential to generate alternative responses in future stages of the pandemic.

Sensory Reweighting During Bipedal Quiet Standing in Adolescents.

A cross-sectional, prospective, between-subjects design was used in this study to establish the differences in sensory reweighting of postural control among different ages during adolescence. A total of 153 adolescents (five age groups; 13-17 years old) performed bipedal standing in three sensory conditions (i.e., with visual restriction, vestibular disturbance, and proprioceptive disturbance). Center of pressure displacement signals were measured in mediolateral and anteroposterior directions to characterize reweighting in the sensory system in static postural control when sensory information is disturbed or restricted during adolescent growth. The results indicate a development of postural control, showing large differences between subjects of 13-14 years old and older adolescents. A critical change was found in sensory reweighting during bipedal stance with disturbance of proprioceptive information at 15 years old. Adolescents of 13-14 years old showed less postural control and performance than older adolescents during the disturbance of proprioceptive information. Moreover, the results demonstrated that the visual system achieves its development around 15-16 years old. In conclusion, this research suggests that a difference of sensory reweighting under this type of sensorial condition and sensory reweight systems would seem to achieve stabilization at the age of 15.

Development and Characterization of Medical Phantoms for Ultrasound Imaging Based on Customizable and Mouldable Polyvinyl Alcohol Cryogel-Based Materials and 3-D Printing: Application to High-Frequency Cranial Ultrasonography in Infants.

This work presents an affordable and easily customizable methodology for phantom manufacturing, which can be used to mimic different anatomic organs and structures. This methodology is based on the use of polyvinyl alcohol-based cryogels as a physical substitute for biologic soft tissues and of 3-D printed polymers for hard tissues, moulding and supporting elements. Thin and durable soft-tissue mimicking layers and multilayer arrangements can be obtained using these materials. Special attention was paid to the acoustic properties (sound speed, attenuation coefficient and mechanical impedance) of the materials developed to simulate soft tissues. These properties were characterized as a function of the additives concentration (propylene-glycol and alumina particles). The polyvinyl alcohol formulation proposed in this work is stable over several freeze-thaw cycles, allowing the manufacturing of multilayer materials with controlled properties. The manufacturing methodology presented was applied to the development of a phantom for high-frequency cranial ultrasonography in infants. This phantom was able to reproduce the main characteristics of the ultrasound images obtained in neonates through the anterior fontanel, down to 8-mm depth.

An author keyword analysis for mapping Sport Sciences.

Scientific production has increased exponentially in recent years. It is necessary to find methodological strategies for understanding holistic or macro views of the major research trends developed in specific fields. Data mining is a useful technique to address this task. In particular, our study presents a global analysis of the information generated during last decades in the Sport Sciences Category (SSC) included in the Web of Science database. An analysis of the frequency of appearance and the dynamics of the Author Keywords (AKs) has been made for the last thirty years. Likewise, the network of co-occurrences established between words and the survival time of new words that have appeared since 2001 has also been analysed. One of the main findings of our research is the identification of six large thematic clusters in the SSC. There are also two major terms that coexist ('REHABILITATION' and 'EXERCISE') and show a high frequency of appearance, as well as a key behaviour in the calculated co-occurrence networks. Another significant finding is that AKs are mostly accepted in the SSC since there has been high percentage of new terms during 2001-2006, although they have a low survival period. These results support a multidisciplinary perspective within the Sport Sciences field of study and a colonization of the field by rehabilitation according to our AK analysis.

Relationship between body composition and vertical ground reaction forces in obese children when walking.

BACKGROUND: Obesity is now a serious worldwide challenge, especially in children. This condition can cause a number of different health problems, including musculoskeletal disorders, some of which are due to mechanical stress caused by excess body weight. The aim of this study was to determine the association between body composition and the vertical ground reaction force produced during walking in obese children. METHODS: Sixteen children participated in the study, six females and ten males [11.5 (1.2) years old, 69.8 (15.5) kg, 1.56 (0.09) m, and 28.36 (3.74) kg/m2 of body mass index (BMI)]. Total weight, lean mass and fat mass were measured by dual-energy X-ray absorptiometry and vertical forces while walking were obtained by a force platform. The vertical force variables analysed were impact and propulsive forces, and the rate of development of both. Multiple regression models for each vertical force parameter were calculated using the body composition variables as input. FINDINGS: The impact force regression model was found to be positively related to the weight of obese children and negatively related to lean mass. The regression model showed lean mass was positively related to the propulsive rate. Finally, regression models for impact and propulsive force showed a direct relationship with body weight. INTERPRETATION: Impact force is positively related to the weight of obese children, but lean mass helps to reduce the impact force in this population. Exercise could help obese persons to reduce their total body weight and increase their lean mass, thus reducing impact forces during sports and other activities.

The progressive focusing correction technique for ultrasound beamforming.

This work presents a novel method for digital ultrasound beamforming based on programmable table look-ups, in which vectors containing coded focusing information are efficiently stored, achieving an information density of a fraction of bit per acquired sample. Timing errors at the foci are within half the period of a master clock of arbitrarily high frequency to improve imaging quality with low resource requirements. The technique is applicable with conventional as well as with deltasigma converters. The bit-width of the focusing code and the number of samples per focus can be defined to improve both memory size and F# with controlled timing errors. In the static mode, the number of samples per focus is fixed, and in the dynamic approach that figure grows progressively, taking advantage of the increasing depth of focus. Furthermore, the latter has the lowest memory requirements. The technique is well suited for research purposes as well as for real-world applications, offering a degree of freedom not available with other approaches. It allows, for example, modifying the sampling instants to phase aberration correction, beamforming in layered structures, etc. The described modular and scalable prototype has been built using low-cost field programmable gate arrays (FPGAs). Experimental measurements are in good agreement with the theoretically expected errors.

Bibliometric study of scientific production on handball / Estudo bibliométrico da produção científica em handebol / Estudio bibliométrico de la producción científica en balonmano

This study carries out a bibliometric analysis of the scientific production on handball with the following goals: (1) to characterize the publications; (2) to analyze productivity; (3) to identify topic areas and journals; and (4) to present the various co-occurrence networks. The analysis consisted of calculating basic bibliometric indicators, and co-occurrence analysis was carried out to establish the relationships between authors, between citations of scientific papers and between keywords chosen by authors. A total of 1,637 original papers and 90 reviews in 399 journals were analyzed; 4,752 authors signed papers related to handball. The main topics were 'handball' and 'ACL,' and a tendency towards increasing presence of papers from the training field was found in recent years.

O objetivo deste estudo foi realizar uma análise bibliométrica da produção científica do handebol com estes objetivos: (1) caracterizar as publicações, (2) analisar a produtividade, (3) identificar as áreas temáticas e as revistas de pesquisa e (4) apresentar as diferentes redes de co-ocorrência. A análise consistiu no cálculo de indicadores bibliométricos básicos e foi realizada uma análise de co-ocorrência para estabelecer as relações entre autores, entre citações de artigos científicos e entre palavras-chave de autores. Foram analisados 1.637 artigos originais e 90 revisões em 399 revistas. Um total de 4.752 autores assinaram artigos relacionados ao termo handebol. Os principais tópicos foram "handball" e "ACL", e encontramos uma tendência nos últimos anos em aumentar a presença de artigos da área de treinamento.

El objetivo de este estudio fue realizar un análisis bibliométrico de la producción científica sobre el balonmano con los siguientes objetivos: (1) caracterizar las publicaciones, (2) analizar la productividad, (3) identificar las áreas temáticas y las revistas y (4) presentar las diferentes redes de coocurrencia. El análisis consistió en el cálculo de indicadores bibliométricos básicos y se realizó un análisis de coocurrencia para establecer las relaciones entre autores, entre citas de artículos científicos y entre palabras clave de los autores. Se analizaron 1637 artículos originales y 90 revisiones en 399 revistas. Un total de 4752 autores firmaron trabajos relacionados con el término balonmano. Los temas principales fueron "handball" y "ACL" y, en los últimos años, hemos encontrado una tendencia de aumento en la presencia de trabajos del ámbito del entrenamiento.

Kinanthropometric assessment of individual, collective and fight sport players from the Spanish national sport technification program / Evaluación cineantropométrica en deportistas individuales, colectivos y de lucha, del programa nacional español de tecnificación deportiva

Nowadays, the study of kinanthropometric parameters is an important tool for both early talent selection and for evaluating the efficacy of a training program. This study aimed to determine the anthropometric characteristics, body composition indicators and somatotype components of individual (athletics, swimming and triathlon), collective (handball and volleyball) and fight (karate and taekwondo) sportsmen and sportswomen from the Valencian Sports Technification Centre. This study involved a total of 62 men and 56 women, they were divided in three subgroups, including individual (athletics, swimming and triathlon), collective (handball and volleyball) and fight (karate and taekwondo) sports. The assessment was carried out according to the one established by the International Society for Advancement of Kinanthropometry (ISAK). For men, the highest value of femur breath, ectomorphy and medial calf and front thigh skinfolds are obtained for triathletes, athletics, volleyball and karate, respectively. The highest values of triceps, biceps and abdominal skinfolds, relaxed arm girth, endomorphy and body fat percentage are shown for taekwondo, while the other highest values are obtained with handball. For women, the highest value of ectomorphy is obtained for athletics. The identified kinanthropometric parameters are useful when comparing between sports and sports subgroups for the selection of subjects and to help in their performance assessment.

En la actualidad, el estudio de los parámetros cineantropométricos es una herramienta importante tanto para la selección temprana del talento como para evaluar la eficacia de un programa de capacitación. Este estudio tuvo como objetivo determinar las características antropométricas, los indicadores de composición corporal y los componentes somatotípicos de deportistas y deportistas individuales (atletismo, natación y triatlón), colectivos (balonmano y voleibol) y de lucha (karate y taekwondo) del Centro Valenciano de Tecnificación Deportiva. Este estudio involucró a un total de 62 hombres y 56 mujeres, se dividieron en tres subgrupos, que incluyen deportes individuales (atletismo, natación y triatlón), colectivos (balonmano y voleibol) y peleas (karate y taekwondo). La evaluación se realizó de acuerdo con la establecida por la Sociedad Internacional para el Avance de la Cineantropometría (ISAK). Para los hombres, el valor más alto de la respiración del fémur, la ectomorfia y los pliegues de la pantorrilla y el muslo frontal se obtienen para triatletas, atletismo, voleibol y karate, respectivamente. Los valores más altos de tríceps, bíceps y pliegues abdominales, circunferencia relajada del brazo, endomorfia y porcentaje de grasa corporal se muestran para el taekwondo, mientras que los otros valores más altos se obtienen con balonmano. Para las mujeres, el mayor valor de la ectomorfía se obtiene para el atletismo. Los parámetros cineantropométricos identificados son útiles cuando se comparan entre deportes y subgrupos deportivos para la selección de sujetos y para ayudar en su evaluación del rendimiento.

Pseudoachalasia of the cardia secondary to nongastrointestinal neoplasia.

A minor proportion of patients with achalasia eventually have a neoplasm and, as a consequence, pseudoachalasia is diagnosed. A neoplasm may either involve gastrointestinal junction or present a paraneoplastic effect. Over the global diagnoses of achalasia issued in 5 years of experience in our motility unit, we have found 13% (3/23 cases) of pseudoachalasia (2-4% in previous series, probably due to the fact that the population assisted was mainly composed of elderly patients). The origin of the neoplasm was bladder, prostate and metastases from epidermoid carcinoma of vocal chord. Treatment of primary neoplasm, besides classical approach (with dilatation of botulinum injection) may help in the resolution of this clinical disorder.