Haemodynamic changes after prolonged water immersion

Abstract

Thermoneutral water immersion increases cardiac preload and changes the neuroendocrine settings of blood volume regulation. The resulting marked diuresis may lead to significant haemodynamic changes after the end of a prolonged water immersion. Ten volunteers underwent 6 h of complete thermoneutral water immersion. Changes in cardiovascular status were assessed 1 h and 16 h after water immersion. Haemodynamic changes were assessed by Doppler echocardiography. Arterial wall distensibility was estimated by pulse wave velocity analysis. One hour after water immersion, mean weight loss was 1.78 kg and urine volume amounted to 1.5 litres. Echocardiographic measurements evidenced a significant decrease in dimensions of the left cardiac chambers and inferior vena cava. The decreased cardiac preload was paralleled by a lower stroke volume and cardiac output. A peripheral vasoconstriction associated with a relative decrease in the lower limb blood flow was evidenced by an increase in carotid-pedal pulse wave velocity and by a decrease in ankle brachial index. Sixteen hours after water immersion, cardiac preload and cardiac output remained below baseline values and peripheral vascular tone was still higher than at baseline. Marked haemodynamic changes had not returned to baseline 16 h after water immersion. There is a need to design fluid-replacement protocols to improve this recovery.     

Metacognitive learning strategies: differential development patterns in high school

The main objective of this study is to identify the development of students’ self-reported use of metacognitive learning strategies during high school. Therefore, the study analyses the differential development patterns of 1,432 students, between grade 10 and 12, in a longitudinal sample. The results suggest that, from a global perspective, there is no development of students’ self-reported use of metacognitive learning strategies during high school. The expected gender-specific differences in favour of female students are replicated in this sample. However, the self-reported use of monitoring and evaluation strategies tends to converge between genders during high school, whereas the differences in the self-reported use of planning strategies remain stable. The consequences for the understanding of metacognitive development are discussed.     

Academic versus industry patenting: An in-depth analysis of what determines patent value

This paper compares corporate and academic patents and tests whether they have similar value distributions and share common determinants of value. The empirical results based on an in-depth analysis of 400 biotech patents applied for by Belgian universities and firms lead to the following observations: (i) academic and corporate patent value distributions have similar levels of ‘skewness’; (ii) the identification of the institutional origin of knowledge allows for an improved understanding of the value determinants and (iii) there is a need to stimulate star scientists to codify their tacit knowledge into valuable patents.     

Archival science facing the information society

It is only a few decades ago that archivists befan to redefine their discipline in terms of a science. This redefinition of archives and records management was the consequence of a growing need for an adequate expression referring to a comprehensive new body of knowledge on records and archives. Consensus on how to adequately define archival science has not been achieved yet, however. As information society evolves, records and archives are changing in nature and status. It is an emerging discipline that has to be defined, which is still bears the impress of the mindset and practices of the industrial society. Bruno Delmas shows the archivist some clues to find a way out of this ambiguity and keep communicating human heritage to unknown generations.     

Conservation strategy for food-based perishable art: preservation versus reconstruction illustrated by Piece in Ghent by Jason Rhoades (1994)

The aim of this paper was to discuss the role of food preservation science and technology in the conservation of complex food-based installations. By introducing the principles of food science and food preservation into the decision-making process for the conservation of contemporary art, more insight on conservation and presentation possibilities was created. Considering the installation Piece in Ghent (P.I.G.) by Jason Rhoades, which contains French fries, the principles of food preservation science were evaluated. The preservation of the original foods was discussed against the potential of a reproduction of the foods. The context for conservation was determined by analysing the artist's intention, the production method of the artwork, and the degradation processes of the food materials. From the results obtained, guidelines to preserve the ‘original’ foods were proposed, as well as guidelines to reproduce foods that can last longer. The study demonstrated that food preservation science contributed to the development of effective strategies for the conservation of contemporary food-based art.     

Space occupation near the basket shapes collective behaviours in youth basketball

This study aimed to analyse how youth basketball players explored numerical overloads during shot attempts by measuring their space occupation across specific court areas. Four process-tracing variables measured how the number of attackers (NA), number of defenders (ND), interpersonal distance between attacker and the closest defender (ID) and distance between attacker and the basket (DBkt) impacted on the performance outcome (converted shot; missed shot; ball possession lost). Ten competitive games involving 13 U14 teams were video recorded and players’ displacements were digitised. The associations between performance outcomes and the process-tracing measures were assessed using standardised mean differences and a cross-correlation function. A multinomial logistic regression was used to calculate the odds ratio (OR) for each of the three possible outcomes. Results revealed that when shot attempts occurred at larger ID and at smaller DBkt, the possibilities to obtain a converted shot increased. The numerical overload of defenders near the scoring target was predominantly associated with offensive success. Also, the possibility of attackers to lead the spatial relation of movements with the defenders, near the scoring target, appeared as a prominent strategy to succeed. In sum, basketball teams that exhibit potential to adapt their collective behaviours to local changes in the environment might be closer to achieving successful outcomes.