Maximal lactate steady state in trained adolescent runners

The aims of this study were: (1) to identify the exercise intensity that corresponds to the maximal lactate steady state in adolescent endurance-trained runners; (2) to identify any differences between the sexes; and (3) to compare the maximal lactate steady state with commonly cited fixed blood lactate reference parameters. Sixteen boys and nine girls volunteered to participate in the study. They were first tested using a stepwise incremental treadmill protocol to establish the blood lactate profile and peak oxygen uptake ([Vdot]O₂). Running speeds corresponding to fixed whole blood lactate concentrations of 2.0, 2.5 and 4.0?mmol?·?l^?1 were calculated using linear interpolation. The maximal lactate steady state was determined from four separate 20-min constant-speed treadmill runs. The maximal lactate steady state was defined as the fastest running speed, to the nearest 0.5?km?·?h^?1, where the change in blood lactate concentration between 10 and 20?min was?<0.5?mmol?·?l^?1. Although the boys had to run faster than the girls to elicit the maximal lactate steady state (15.7 vs 14.3?km?·?h^?1, P?<0.01), once the data were expressed relative to percent peak [Vdot]O₂ (85 and 85%, respectively) and percent peak heart rate (92 and 94%, respectively), there were no differences between the sexes (P?>0.05). The running speed and percent peak [Vdot]O₂ at the maximal lactate steady state were not different to those corresponding to the fixed blood lactate concentrations of 2.0 and 2.5?mmol?·?l^?1 (P?>0.05), but were both lower than those at the 4.0?mmol?·?l^?1 concentration (P?<0.05). In conclusion, the maximal lactate steady state corresponded to a similar relative exercise intensity as that reported in adult athletes. The running speed, percent peak [Vdot]O₂ and percent peak heart rate at the maximal lactate steady state are approximated by the fixed blood lactate concentration of 2.5?mmol?·?l^?1 measured during an incremental treadmill test in boys and girls.     

An investigation on the unwillingness of nodes to participate in mobile delay tolerant network routing

Message routing in mobile delay tolerant networks inherently relies on the cooperation between nodes. In most existing routing protocols, the participation of nodes in the routing process is taken as granted. However, in reality, nodes can be unwilling to participate. We first show in this paper the impact of the unwillingness of nodes to participate in existing routing protocols through a set of experiments. Results show that in the presence of even a small proportion of nodes that do not forward messages, performance is heavily degraded. We then analyze two major reasons of the unwillingness of nodes to participate, i.e., their rational behavior (also called selfishness) and their wariness of disclosing private mobility information.     

Anatomy practical examinations: How does student performance on computerized evaluation compare with the traditional format?

Practical examinations in anatomy are usually conducted on specimens in the anatomy laboratory (referred to here as the “traditional” method). Recently, we have started to administer similar examinations online using the quiz facility in Moodle?. In this study, we compare student scores between two assessment environments viz. online and traditional environments. We hypothesized that regardless of the examination medium (traditional or online) overall student performance would not be significantly different. For the online medium, radiological images, prosected specimens, and short video clips demonstrating muscle action were first acquired from resources used for teaching during anatomy practical classes. These were optimized for online viewing and then uploaded onto Moodle learning management software. With regards to the traditional format, actual specimens were usually laid out in a circular stream. Identification tags were then attached to specific spots on the specimens and questions asked regarding those identified spots. A cohort of students taking practical examinations in six courses was studied. The courses were divided into three pairs with each pair credit‐weight matched. Each pair consisted of a course where the practical examination was conducted online and the other in the traditional format. There was no significant difference in the mean scores within each course pair. In addition, a significant positive correlation between score in traditional and online formats was found. We conclude that mean grades in anatomy practical examination conducted either online or in the traditional format were comparable. These findings should reassure teachers intending to use either format for their practical examinations. Anat Sci Educ. © 2011 American Association of Anatomists.     

Wear behavior of copper-containing ferritic iron under a dry sliding condition

The effect of solute Cu and Cu precipitates on the wear behavior of ferritic iron under an unlubricated condition was investigated. The specific wear rate of Cu-containing steel abruptly decreased up to 50 N of load, and then gradually decreased with further increased load. The specific wear rate of the as-quenched specimen, in which Cu was in a solid solution, was the lowest among all the specimens at low loads, and all specimens had almost the same specific wear rate at high loads. Subsurface observation showed that the hardness increments of all specimens decreased with increased depth below the worn surface. The as-quenched specimen had a relatively large depth of deformed region than the other specimens even though the increments in hardness were almost the same for all specimens at low loads. With the same hardness at an unworn state, the as-quenched and over-aged specimens exhibited a substantial increase in hardness and large deformed regions below the worn surfaces. This finding indicated that the enhancement in plastic deformation and work hardening led to the decrease in the specific wear rate of the as-quenched specimen at low loads and the improvement in the wear resistance of all specimens at high loads.     

Multilingual language use and television exposure and preferences: The case of Belize 1

This paper discusses the relationship between the language use patterns of multilinguals and their media preferences and exposure. Specifically, it examines the language behavior of multilinguals in Belize where television is available in both English and Spanish. A survey of Belizean high school students conducted in both languages, asked about their sociolinguistic patterns and media preferences and exposure. The results indicate that the frequency of a particular language's use correlates with preferences for and exposure to television in that language. This relationship is more pronounced when specific cultural programming is considered.     

A CRISPR/Cas12a-empowered surface plasmon resonance platform for rapid and specific diagnosis of the Omicron variant of SARS-CoV-2

The outbreak of the COVID-19 pandemic was partially due to the challenge of identifying asymptomatic and presymptomatic carriers of the virus, and thus highlights a strong motivation for diagnostics with high sensitivity that can be rapidly deployed. On the other hand, several concerning SARS-CoV-2 variants, including Omicron, are required to be identified as soon as the samples are identified as ‘positive’. Unfortunately, a traditional PCR test does not allow their specific identification. Herein, for the first time, we have developed MOPCS (Methodologies of Photonic CRISPR Sensing), which combines an optical sensing technology-surface plasmon resonance (SPR) with the ‘gene scissors’ clustered regularly interspaced short palindromic repeat (CRISPR) technique to achieve both high sensitivity and specificity when it comes to measurement of viral variants. MOPCS is a low-cost, CRISPR/Cas12a-system-empowered SPR gene-detecting platform that can analyze viral RNA, without the need for amplification, within 38 min from sample input to results output, and achieve a limit of detection of 15 fM. MOPCS achieves a highly sensitive analysis of SARS-CoV-2, and mutations appear in variants B.1.617.2 (Delta), B.1.1.529 (Omicron) and BA.1 (a subtype of Omicron). This platform was also used to analyze some recently collected patient samples from a local outbreak in China, identified by the Centers for Disease Control and Prevention. This innovative CRISPR-empowered SPR platform will further contribute to the fast, sensitive and accurate detection of target nucleic acid sequences with single-base mutations.     

Creativity,Culture and Education 1

This study investigated differences in creativity between traditionally and modern educated students in the Sudan. The Alternative Uses Test was applied to a group of 207 students, 120 male and 87 female with an age range of 19‐23 years. The results indicated that the modern educated group obtained significantly higher scores. Internal cultural factors as well as external factors account for the results. Mutual adaptation and reconciliation between traditional and modem culture are necessary in order to take advantage of the positive aspects of both.

     

American influencies in Brazilian physical education: clues in the specialised periodical press (1932–1950)

This study investigates the American presence and influences in the physical education press to understand the way in which that presence influenced and contributed to the production of a sports culture in the first half of the twentieth century. As historical sources, the study uses periodicals in the field that were published in the period 1932–1950. As a theoretical frame of reference, it uses the repertoire of the New Cultural History in terms of strategy, tactics and devices. It is written in a narrative way, following Ginzburg's style, presenting data and contextualizing them with the historic scene. Clues enabled us to infer that the American presence, which was catalysed by the Brazilian Young Men's Christian Association (YMCA), sought to shape a sports culture from physical education and society. This effort reflected the yearning of Brazilian intellectuals for modernisation and an attempt at cultural colonisation by the government of the USA.     

Development of creativity: The influence of varying levels of implementation of the DISCOVER curriculum model, a non-traditional pedagogical approach

Development of creativity is influenced by multiple factors, including the environment, developmental changes, and measurement tools. In this study, we investigated the relationship between creativity development and implementation of the Discovering Intellectual Strengths and Capabilities while Observing Varied Ethnic Responses (DISCOVER) curriculum model. Using the Test of Creative Thinking–Drawing Production (TCT-DP), 1986 culturally diverse, low-income students, K through 6, in four elementary schools in the U.S. were assessed for three consecutive years. The creativity of all children increased from grades K to 6, but children in classrooms of low implementers demonstrated a dip and some “pauses.” Differences in scores of children in middle/high and low implementers' classrooms were significant. The implication is that creativity development is supported through active learning, student choice, access to varied materials, exploration, self-evaluation, problem finding, and problem solving. Additional analyses need to be conducted to uncover cultural and linguistic influences in these four schools.