Performance Tiers within a Competitive Age Group of Young Swimmers Are Characterized by Different Kinetic and Kinematic Behaviors

The present study aimed to analyze swimmers’ in-water kinetic and kinematic behaviors according to different swimming performance tiers within the same age group. An amount of 53 highly trained swimmers (girls and boys: 12.40 ± 0.74 years) were split up into 3 tiers based on their personal best performance (i.e., speed) in the 50 m freestyle event (short-course): lower-tier (1.25 ± 0.08 m·s−1); mid-tier (1.45 ± 0.04 m·s−1); and top-tier (1.60 ± 0.04 m·s−1). The in-water mean peak force was measured during a maximum bout of 25 m front crawl using a differential pressure sensors system (Aquanex system, Swimming Technology Research, Richmond, VA, USA) and defined as a kinetic variable, while speed, stroke rate, stroke length, and stroke index were retrieved and considered as kinematic measures. The top-tier swimmers were taller with a longer arm span and hand surface areas than the low-tier, but similar to the mid-tier. While the mean peak force, speed and efficiency differed among tiers, the stroke rate and stroke length showed mixed findings. Coaches should be aware that young swimmers belonging to the same age group may deliver different performance outcomes due to different kinetic and kinematic behaviors.Portuguese Foundation for Science and Technology (FCT),Grants 2020.08326.BD and UIDB04045/202

Proposal of a method for fluorimetric analysis of malvin in red wines

A fluorimetric method for the quantitative determination of malvin (malvidin 3,5-diglucoside) in red wines is described. The method is based on previous fractionation of the wine in a Polyclar AT column and later formation of a fluorophore, by oxidation of the malvin. The proposed method has good precision and accuracy and when applied to hybrid red wines affords results significantly comparable with those obtained by HPLC

The sustainable transformation of business events: Sociodemographic variables as determinants of attitudes toward sustainable academic conferences

Purpose – This study aimed to assess whether sociodemographic variables explain significant differences in attitudes towards transforming academic conferences into more sustainable events. Design/methodology/approach – An analytical model of participants' attitudes towards sustainable conferences based on literature review as well as the theories of reasoned action and planned behavior was developed and applied to a sample of 532 surveyed individuals from 68 countries who regularly attended academic conferences in the last five years prior to 2020. The results were refined using statistical and computational techniques to achieve more empirically robust conclusions. Findings – Results reveal that sociodemographic variables such as attendees' gender and age explain differences in attitudes. Women and older adults have stronger pro-environmental attitudes regarding event sustainability. On the other hand, attitudes towards more sustainable academic conferences are quite strong and positive overall. More sustainable events' venues, catering, conference materials, and accommodations strongly influence attendees' attitudes towards more sustainable conferences. The strength of attitudes was weaker towards transportation. Originality/value – To our best knowledge, this research is the first to assess whether sociodemographic variables explain significant differences in attitudes towards the sustainable transformation of academic conferences.info:eu-repo/semantics/publishedVersio

Holiday rentals in cultural tourism destinations: a comparison of booking.com-based daily rate estimation for Seville and Porto

Multiple variables determine holiday rentals’ price composition in cultural tourism destinations. This study sought, first, to test a model including the variables with the greatest impact on tourism accommodations’ prices in these destinations and, second, to demonstrate the proposed model’s applicability to cultural city destinations by identifying the adaptations needed to apply it to different contexts. Two cities were selected for the model application—Seville in Spain and Porto in Portugal—both of which are located in different countries and are well-known cultural tourism destinations. The data were extracted from Booking.com because this accommodations platform has adapted its offer to the sharing economy, becoming one of the most important players in the market, and because research on holiday rentals using data from Booking.com is scarce. The results show that the variables used are relevant and highlight the adaptations necessary for specific cultural tourism destinations, thereby indicating that the model can be applied to all cultural tourism destinations. The proposed approach can help holiday rental managers select the correct tools for determining their accommodation units’ daily rates according to their product and marketing context’s characteristics.info:eu-repo/semantics/publishedVersio

Reducing techno-anxiety in high school teachers by improving their ICT problem-solving skills

Teachers need to continuously update their information and communication technologies (ICT) knowledge, but they are usually not trained to deal with the problems arising from their use. In fact, studies in the literature report techno-anxiety (i.e. unpleasant physiological activation and discomfort due to present or future use of ICT) in teachers. Thus, the goal of this action research is to study if teachers’ techno-anxiety can be reduced by increasing their ability to solve technological problems. An inter-subject experiment has been carried out with 46 teachers. High school teachers were chosen because they are digital immigrants, while at the moment of this research their students are digital natives (born around year 2000). Since we could not find any specific training for teachers to increase their resolution skills of technological problems, in order to apply the treatment for our study, we have designed and deployed an online course about ICT problem-solving skills based on the 70/20/10 model for learning and development. Results show the success of the course when it comes to increasing the ICT problem-solving skills and to reducing techno-anxiety.Preprin

Rasgrf2 controls dopaminergic adaptations to alcohol in mice

A.C. Easton et al.Alcohol abuse leads to serious health problems with no effective treatment available. Recent evidence suggests a role for ras-specific guanine-nucleotide releasing factor 2 (RASGRF2) in alcoholism. Rasgrf2 is a calcium sensor and MAPK/ERK activating protein, which has been linked to neurotransmitter release and monoaminergic receptor adaptations. Rasgrf2 knock out (KO) mice do not develop a dopamine response in the nucleus accumbens after an alcohol challenge and show a reduced consumption of alcohol. The present study aims to further characterise the role of Rasgrf2 in dopaminergic activation beyond the nucleus accumbens following alcohol treatment. Using in vivo microdialysis we found that alcohol induces alterations in dopamine levels in the dorsal striatum between wildtype (WT) and Rasgrf2 KO mice. There was no difference in the expression of dopamine transporter (DAT), dopamine receptor regulating factor (DRRF), or dopamine D2 receptor (DRD2) mRNA in the brain between Rasgrf2 KO and WT mice. After sub-chronic alcohol treatment, DAT and DRRF, but not DRD2 mRNA expression differed between WT and Rasgrf2 KO mice. Brain adaptations were positively correlated with splenic expression levels. These data suggest that Rasgrf2 controls dopaminergic signalling and adaptations to alcohol also in other brain regions, beyond the nucleus accumbens.This work was supported by the Biomedical Research Council (U.K.) and funds of the Friedrich-Alexander-University Erlangen-Nuremberg. A.E. is a recipient of a studentship from the Medical Research Council, U.K. AFM and ES were supported by grants PI13/02846 and RD12/0036/0001 (MINECO) and SA181U13 (JCyL), Spain.Peer Reviewe

The sustainable transformation of business events: sociodemographic variables as determinants of attitudes towards sustainable academic conferences

PurposeThis study aimed to assess whether sociodemographic variables explain significant differences in attitudes towards transforming academic conferences into more sustainable events.Design/methodology/approachAn analytical model of participants' attitudes towards sustainable conferences based on literature review as well as the theories of reasoned action and planned behaviour was developed and applied to a sample of 532 surveyed individuals from 68 countries who regularly attended academic conferences in the last five years prior to 2020. The results were refined using statistical and computational techniques to achieve more empirically robust conclusions.FindingsResults reveal that sociodemographic variables such as attendees' gender and age explain differences in attitudes. Women and older adults have stronger pro-environmental attitudes regarding event sustainability. On the other hand, attitudes towards more sustainable academic conferences are quite strong and positive overall. More sustainable events' venues, catering, conference materials and accommodations strongly influence attendees' attitudes towards more sustainable conferences. The strength of attitudes was weaker towards transportation.Research limitations/implicationsFirst, the analyses focused on only aspects related to the attendees' attitudes. Assessing their real behaviour would complete this research. The geographical areas defined by the U.N. and used in this study have the limitation of combining highly developed countries and developing countries in the same geographical area, for example, the Americas and Asia and the Pacific.Practical implicationsSpecific socio-demographic variables' effects on attitudes towards sustainable academic conferences can indicate how organisers can best promote these events according to attendees' characteristics and develop differentiated marketing campaigns. For women and older adults, event sustainability should be emphasised as a competitive strategy to promote events and attract these audiences. Marketing strategies for younger attendees (under 30 years old) could focus on technology, networking or attractive social programmes. Sustainable venues, catering, conference materials and accommodations are easier to promote. Event organisers should encourage participants to make more environmentally friendly decisions regarding more sustainable event transport.Social implicationsA strategy based on promoting the event as contributing to sustainable development could educate attendees and put them on the path to developing stronger positive attitudes regarding sustainability and more sustainable behaviours. Sustainable academic conferences can educate students, organisers, service providers and delegates through their involvement in sustainable practices.Originality/valueTo our best knowledge, this research is the first to assess whether sociodemographic variables explain significant differences in attitudes towards the sustainable transformation of academic conferences.info:eu-repo/semantics/publishedVersio

Rasgrf2 controls noradrenergic involvement in the acute and subchronic effects of alcohol in the brain

et al.[Rationale]: Alcohol addiction is a major psychiatric disease, and yet, the underlying molecular adaptations in the brain remain unclear. Recent evidence suggests a functional role for the ras-specific guanine-nucleotide releasing factor 2 (Rasgrf2) in alcoholism. Rasgrf2−/− mice consume less alcohol and show entirely absent dopamine responses to an alcohol challenge compared to wild types (WT). [Objective]: In order to further investigate how Rasgrf2 modifies the acute and subchronic effects of alcohol in the brain, we investigated its effects on the noradrenergic and serotonergic systems. [Methods]: We measured noradrenaline and serotonin activity in the brain by in vivo microdialysis and RNA expression by chip analysis and RT-PCR after acute and sub-chronic alcohol exposure in Rasgrf2−/− and WT mice. [Results]: In vivo microdialysis showed a significantly reduced noradrenergic response and an absent serotonergic response in the nucleus accumbens (NAcc) and caudate putamen (CPu) after an alcohol challenge in Rasgrf2−/− mice. A co-expression analysis showed that there is a high correlation between Rasgrf2 and α2 adrenoceptor RNA expression in the ventral striatum in naïve animals. Accordingly, we further assessed the role of Rasgrf2 in the response of the noradrenergic system to subchronic alcohol exposure. A decrease in β1 adrenoceptor gene expression was seen in Rasgrf2+/+, but not Rasgrf2−/− mice following alcohol exposure. Conversely, alcohol resulted in a decrease in both β2 and α2 adrenoceptor gene expression in knockout but not WT Rasgrf2 mice. [Conclusions]: These findings suggest that adaptations in the noradrenergic system contribute to the Rasgrf2 enhanced risk of alcoholism.This work was supported by funds of the Institute of Psychiatry, King’s College London and the Friedrich-Alexander-University Erlangen-Nuremberg. A.E. is a recipient of a studentship from the Medical Research Council (UK). AFM and ES were supported by FIS and RTICC grants from ISCIII (Spain).Peer Reviewe

The coactivator PGC-1α regulates mouse skeletal muscle oxidative metabolism independently of the nuclear receptor PPARβ/δ in sedentary mice fed a regular chow diet

AIMS/HYPOTHESIS: Physical activity improves oxidative capacity and exerts therapeutic beneficial effects, particularly in the context of metabolic diseases. The peroxisome proliferator-activated receptor (PPAR) γ coactivator-1α (PGC-1α) and the nuclear receptor PPARβ/δ have both been independently discovered to play a pivotal role in the regulation of oxidative metabolism in skeletal muscle, though their interdependence remains unclear. Hence, our aim was to determine the functional interaction between these two factors in mouse skeletal muscle in vivo. METHODS: Adult male control mice, PGC-1α muscle-specific transgenic (mTg) mice, PPARβ/δ muscle-specific knockout (mKO) mice and the combination PPARβ/δ mKO + PGC-1α mTg mice were studied under basal conditions and following PPARβ/δ agonist administration and acute exercise. Whole-body metabolism was assessed by indirect calorimetry and blood analysis, while magnetic resonance was used to measure body composition. Quantitative PCR and western blot were used to determine gene expression and intracellular signalling. The proportion of oxidative muscle fibre was determined by NADH staining. RESULTS: Agonist-induced PPARβ/δ activation was only disrupted by PPARβ/δ knockout. We also found that the disruption of the PGC-1α-PPARβ/δ axis did not affect whole-body metabolism under basal conditions. As expected, PGC-1α mTg mice exhibited higher exercise performance, peak oxygen consumption and lower blood lactate levels following exercise, though PPARβ/δ mKO + PGC-1α mTg mice showed a similar phenotype. Similarly, we found that PPARβ/δ was dispensable for PGC-1α-mediated enhancement of an oxidative phenotype in skeletal muscle. CONCLUSIONS/INTERPRETATION: Collectively, these results indicate that PPARβ/δ is not an essential partner of PGC-1α in the control of skeletal muscle energy metabolism