Preparation of iron oxide nanopowders by the radiation-chemical method

Various magnetic nanopowders of iron oxide were obtained using the radiation-chemical method when irradiated with a nanosecond electron beam. The main physical and chemical characteristics of the prepared nanopowders were studied, such as structure, porosity, thermal resistance and magnetic properties. It was found that, by selecting precursors and the composition of the solution, it is possible to control not only the textural properties and yield of the obtained nanopowders (by changing the dose and dose rate intensity of the electron beam), but also to obtain crystalline or amorphous nanopowders, on which their magnetic properties depend.

The Effect of Aerobic Exercise Training Frequency on Arterial Stiffness in a Hyperglycemic State in Middle-Aged and Elderly Females

The frequency of aerobic exercise training in reducing the increase in arterial stiffness during acute hyperglycemia, a risk factor for cardiovascular disease, is unknown. The aim of the study was to determine the aerobic exercise training frequency on arterial stiffness in a hyperglycemic state in middle-aged and elderly females. Twenty healthy elderly people were randomly assigned to a two-times-a-week (T2, n = 10) and four-times-a-week (T4, n = 10) exercise group. All participants exercised for 35 min per session, which consisted of jogging exercises with a heart rate intensity of 65%. Brachial-ankle (ba), and heart-brachial (hb) pulse wave velocity (PWV) were measured before, 4 and 8 weeks after intervention; before the oral ingestion of 75-g of glucose; and 30, 60, and 90 min after ingestion. The baPWV before and 4 weeks after the intervention increased in both groups (p < 0.05), but only increased 8 weeks after intervention in the T2 group. hbPWV was unchanged before, 4 and 8 weeks after intervention in both groups. These findings show that frequent aerobic exercise suppresses the increase in arterial stiffness following glucose intake. The results of this study can be used to support the implementation of exercise programs for middle-aged and elderly patients.

Evaluation of antigenicity and nutritional properties of enzymatically hydrolyzed cow milk

While enzymatic hydrolysis is an effective method for lowering the antigenicity of cow milk (CM), research regarding the antigenicity and nutritional traits of CM hydrolysate is limited. Here, we evaluated the protein content, amino acid composition, sensory traits, color, flow behavior, and antigenicity of CM following enzymatic hydrolysis. The results showed that enzymatic hydrolysis increased the degree of hydrolysis, destroyed allergenic proteins, including casein, β-lactoglobulin, and ɑ-lactalbumin, and significantly increased the content of free amino acids and nutritional quality. In particular, the antigenicity of CM was significantly reduced from 44.05 to 86.55% (P < 0.5). Simultaneously, the taste, color, and flow behavior of CM were altered, the sweetness and richness intensity decreased significantly (P < 0.5), and astringency and bitterness were produced. A slightly darker and more yellow color was observed in CM hydrolysate. In addition, apparent viscosity decreased and shear stress significantly increased with increasing shear rate intensity. The results will provide a solid theoretical foundation for the development of high-quality hypoallergenic dairy products.

Functional and Operational Requirements to Be Fulfilled by Conical Picks Regarding Their Wear Rate and Investment Costs

User’s choices of conical picks currently involve specifying their material and geometric parameters (functional requirements), incorporating the place and conditions of their work (operational requirements). The selection is usually made based on solely one criterion, which is the price. Thus, at the stage of both purchase and operation, the quality of picks, as well as their matching for a specific machine, are not assessed. The problem of defining whether the producer has fulfilled the user’s requirements arises only when the user questions the picks’ quality. Analysis of this problem has resulted in developing assumptions, concepts and research procedures based on the cutting process requirements. The procedure allows conducting tests to determine the geometric parameters of a pick, the type of material of the pick body and WC-Co insert, as well as the pick wear rate (intensity). The C2 index describes the wear rate (intensity)—the smaller its value, the slower the pick’s wear. Laboratory tests were carried out at the AGH University of Science and Technology in Kraków, Poland. Following the developed method and procedure, the quality of picks was precisely and unambiguously assessed. The C2 index, apart from testing the quality of picks, was also used to forecast their wear. Based on the C2 index, a method is proposed to estimate the wear rate of conical picks provided by different manufacturers and determine the acceptable unit price and operating costs. Thus, it is possible and reasonable to precisely define the investment requirements and appropriately select the pick. Relevant tests were carried out for eight different types of conical picks used in roadheaders, longwall shearers and shaft-boring roadheaders.

Oxygen Uptake Kinetics in Endurance Trained Youth and Adult Cyclists

Previous studies reported faster pulmonary oxygen uptake kinetics at the onset of exercise in untrained youth compared with adults. Whether or not these differences are identical for trained groups have not been examined. The purpose of this study was to compare ̇VO2 kinetics of youth and adult cyclists at moderate and heavy-intensity exercise. Thirteen adult (age: 23.2 ± 4.8 years; ̇VO2peak 68.4 ± 6.8 mL·min-1.kg-1) and thirteen youth cyclists (age: 14.3 ± 1.5 years; ̇VO2peak 61.7 ± 4.3 mL·min-1.kg-1) completed a series of 6-min square wave exercises at moderate and heavy-intensity exercise at 90 rev·min-1. A two-way repeated-measure ANOVA was conducted to identify differences between groups and intensities. The time constant, time delay and the mean response time were not significantly different between youth and adult cyclists (p > 0.05). We found significant differences between intensities, with a faster time constant during moderate than heavy-intensity exercise in youth (24.1 ± 7.0 s vs. 31.8 ± 5.6 s; p = 0.004) and adults (22.7 ± 5.6 s vs. 28.6 ± 5.7 s; p < 0.001). The present data suggest that the effect of training history in adult cyclists compensate for the superior primary response of the oxygen uptake kinetics typically seen in youth compared to adults. Furthermore, the ̇VO2 response is dependent of work rate intensity in trained youth and adult cyclists.

Comparison of intensity and post-effort response in three interval trainings in young tennis players: running interval, specific interval, and specific intermittent training

Introduction: In recent years, considerable interest has been shown in adapting training to the specific characteristics of tennis. The use of intermittent exercise seems to adapt better to the sport’s work/recovery structure and using specific movements allows for local adaptations and complex work. Nevertheless, we need to achieve a level of intensity that is at least similar to what is achieved when continuous running is used. The ability to recover between points is also a decisive factor in terms of performance. Our hypothesis is that recovery depends on stimulus type, which means the most suitable stimuli must be chosen to improve this capacity. Material and method: Our study’s goal was to compare the intensity and post-effort behaviour triggered by three types of exercise: continuous running with 2-minute intervals (GIT), rallies with 2-minute intervals (SIT) and intermittent rallies (SIIT). We measured heart rate (HR) and blood lactate levels during the three exercises, as well as the recovery to 130 beats and in the first 10 and 20 seconds post-effort. Results: Heart rate intensity was significantly higher in SIT than in GIT and lactate levels were higher in both SIT and SIIT compared to GIT. Heart rate recovery is significantly slower in both specific exercises, increasing in the first 10 and 20 seconds with SIIT. Discussion: We have reached the conclusion that specific training led to greater intensity in the specific exercises. Post-effort response is slower in the specific trainings and paradoxical in the initial seconds of intermittent training.

The Incidence, Intensity, and Risk Factors for Soil Transmissible Helminthes Infections among Waste Handlers in a Large Coastal Periurban Settlement in Southern Ghana

Soil-transmissible helminthes (STH) infections are among the most common sanitation-related public health problems in poor periurban settlements of tropical regions of low- and middle-income countries. In Ghana, research studies documenting the incidence rate, intensity, and occupational risk factors of STH infections among adults are scanty. A prospective cohort study of 261 waste handlers was conducted to investigate this. Stool samples were collected after 90 and 180 days of treatment with albendazole (400 mg per dose). The geometric mean intensity of STH among waste handlers after 180 days of treatment was 2.8 eggs/gram (light intensity), with an incidence rate of 1.5%. The proportion of waste handlers with light intensity STH infections was 4.8%. The odds of STH infection among female waste handlers were 80% lower when compared with male waste handlers (aOR = 0.2; 95% CI: 0.0–0.8). Waste handlers who used rubber gloves when working were 80% (aOR = 0.2: 95% CI: 0.2–1.9) protected from STH infections compared with those who did not use gloves. Infections with STH among the 261 waste handlers significantly correlated with the type of waste handling activities (LR χ2 = 15.3; p = 0.033 ) with the highest proportion of infection found among transporters, 2 (40%). Waste handlers should receive periodic antihelminthic treatment, at least once every six months, practice adequate hand hygiene, and use suitable personal protective equipment during work.

High resolution proximity statistics as early warning for US universities reopening during COVID-19

Reopening of colleges and universities for the Fall semester of 2020 across the United States has caused significant COVID-19 case spikes, requiring reactive responses such as temporary closures and switching to online learning. Until sufficient levels of immunity are reached through vaccination, Institutions of Higher Education will need to balance academic operations with COVID-19 spread risk within and outside the student community. In this work, we study the impact of proximity statistics obtained from high resolution mobility traces in predicting case rate surges in university counties. We focus on 50 land-grant university counties (LGUCs) across the country and show high correlation (PCC > 0.6) between proximity statistics and COVID-19 case rates for several LGUCs during the period around Fall 2020 reopenings. These observations provide a lead time of up to ∼3 weeks in preparing resources and planning containment efforts. We also show how features such as total population, population affiliated with university, median income and case rate intensity could explain some of the observed high correlation. We believe these easily explainable mobility metrics along with other disease surveillance indicators can help universities be better prepared for the Spring 2021 semester.

Computer-aided teaching mode of oral English intelligent learning based on speech recognition and network assistance

The purpose of this paper is to use English specific syllables and prosodic features in spoken speech data to carry out English spoken recognition, and to explore effective methods for the design and application of English speech detection and automatic recognition systems. The method proposed by this study is a combination of SVM_FF based classifier, SVM_IER based classifier and syllable classifier. Compared with the method based on the combination of other phonological characteristics such as phonological rate, intensity, formant and energy statistics and pronunciation rate, and the syllable-based classifier based on specific syllable training, a better recognition rate is obtained. In addition, this study conducts simulation experiments on the proposed English recognition and identification method based on specific syllables and prosodic features and analyzes the experimental results. The result found that the recognition performance of the English spoken recognition system constructed by this study is significantly better than the traditional model.