Abstract
Stress is a reaction of the body to external challenges, whether physical or psychological. In sports, there are stress factors that affect the athlete's performance, especially in team ...sports that involve short, high-intensity exercise cycles followed by short recovery periods, such as American football. The lack of stress regulation mechanisms can be detrimental to the individual and collective performance of athletes. Biofeedback systems have shown promising clinical results in regulating stress for sports competitions. However, there is a lack of scientific evidence to support their efficacy, and technologies, such as virtual reality videogames, have not been extensively explored. In this article, we present the development and pilot testing of Virtual Autonomic Nervous System (VANS), a virtual reality videogame using biofeedback that supports stress management training in athletes. VANS uses an optical heart rate sensor and aims at keeping the heart rate below a given threshold to control features within the game. We evaluated the usability and user experience of VANS through a 1-week deployment study with 10 American footballers. Our results show that VANS outperformed a commercial videogame used for biofeedback training and considerably reduced stress in our participants. Therefore, VANS could provide stress management training for future matches and competitions. Finally, we reflect on aspects of our design and discuss future directions of our work.
Acute respiratory distress syndrome (ARDS) is a clinical entity that acutely affects the lung parenchyma, and is characterized by diffuse alveolar damage and increased pulmonary vascular ...permeability. Currently, computed tomography (CT) is commonly used for classifying and prognosticating ARDS. However, performing this examination in critically ill patients is complex, due to the need to transfer these patients to the CT room. Fortunately, new technologies have been developed that allow the monitoring of patients at the bedside. Electrical impedance tomography (EIT) is a monitoring tool that allows one to evaluate at the bedside the distribution of pulmonary ventilation continuously, in real time, and which has proven to be useful in optimizing mechanical ventilation parameters in critically ill patients. Several clinical applications of EIT have been developed during the last years and the technique has been generating increasing interest among researchers. However, among clinicians, there is still a lack of knowledge regarding the technical principles of EIT and potential applications in ARDS patients. The aim of this review is to present the characteristics, technical concepts, and clinical applications of EIT, which may allow better monitoring of lung function during ARDS.
Archaeologists often argue whether Paleolithic works of art, cave paintings in particular, constitute reflections of the natural environment of humans at the time. They also debate the extent to ...which these paintings actually contain creative artistic expression, reflect the phenotypic variation of the surrounding environment, or focus on rare phenotypes. The famous paintings "The Dappled Horses of Pech-Merle," depicting spotted horses on the walls of a cave in Pech-Merle, France, date back ∼25,000 y, but the coat pattern portrayed in these paintings is remarkably similar to a pattern known as "leopard" in modern horses. We have genotyped nine coat-color loci in 31 predomestic horses from Siberia, Eastern and Western Europe, and the Iberian Peninsula. Eighteen horses had bay coat color, seven were black, and six shared an allele associated with the leopard complex spotting (LP), representing the only spotted phenotype that has been discovered in wild, predomestic horses thus far. LP was detected in four Pleistocene and two Copper Age samples from Western and Eastern Europe, respectively. In contrast, this phenotype was absent from predomestic Siberian horses. Thus, all horse color phenotypes that seem to be distinguishable in cave paintings have now been found to exist in prehistoric horse populations, suggesting that cave paintings of this species represent remarkably realistic depictions of the animals shown. This finding lends support to hypotheses arguing that cave paintings might have contained less of a symbolic or transcendental connotation than often assumed.
Abstract Muslim religion has strict rules to determine what kinds of foodstuffs, and under what circumstances, are deemed appropriate for consumption. Fishes are not an exception to this rule and ...features such as body shape or the presence and conspicuousness of scales dictate whether certain species are acceptable or rejected. In this paper, an overview of the Iberian ichthyoarchaeological record from Muslim sites is presented to ascertain whether differences with Christian sites existed in terms of these characters and to what extent these allow one to take fish assemblages as cultural proxies of archaeological deposits. In the case of coastal (production) sites, we also consider whether the peculiarities a given fish assemblage exhibit reflect instead certain environmental features such as the biotopes where a given local fishery operated.
Polycrystalline thin film CdTe continues to be a leading material for the development of cost effective and reliable photovoltaics. The two key properties of this material are its band gap (1.5
eV), ...close to the ideal for photovoltaic conversion efficiency (1.45
eV), and its high optical absorption coefficient. Thin film CdTe solar cells are typically hetero-junctions with CdS being the n-type partner, or window layer. Efficiencies as high as 16.5% have been achieved, but still there is some potential for increasing them.
We make an analysis of the typical CdS/CdTe superstrate solar cell, and from it we establish critical issues and different lines of research in order to improve the current efficiencies. We also show that present record efficiencies are very close to the practical efficiency limit for a CdS/CdTe hetero-junction cell.
Domestic horses represent a genetic paradox: although they have the greatest number of maternal lineages (mtDNA) of all domestic species, their paternal lineages are extremely homogeneous on the ...Y-chromosome. In order to address their huge mtDNA variation and the origin and history of maternal lineages in domestic horses, we analyzed 1961 partial d-loop sequences from 207 ancient remains and 1754 modern horses. The sample set ranged from Alaska and North East Siberia to the Iberian Peninsula and from the Late Pleistocene to modern times. We found a panmictic Late Pleistocene horse population ranging from Alaska to the Pyrenees. Later, during the Early Holocene and the Copper Age, more or less separated sub-populations are indicated for the Eurasian steppe region and Iberia. Our data suggest multiple domestications and introgressions of females especially during the Iron Age. Although all Eurasian regions contributed to the genetic pedigree of modern breeds, most haplotypes had their roots in Eastern Europe and Siberia. We found 87 ancient haplotypes (Pleistocene to Mediaeval Times); 56 of these haplotypes were also observed in domestic horses, although thus far only 39 haplotypes have been confirmed to survive in modern breeds. Thus, at least seventeen haplotypes of early domestic horses have become extinct during the last 5,500 years. It is concluded that the large diversity of mtDNA lineages is not a product of animal breeding but, in fact, represents ancestral variability.
The use of coastal resources has been crucial for human diet and social behaviour evolution has been extensively documented since the Middle Palaeolithic, mainly in the western Mediterranean and ...southern Africa. In southern Iberia, the mollusc assemblages associated with archaeological sites show a continuous record regardless of palaeoclimatic conditions. Among these, limpets are uninterruptedly abundant from the Middle Palaeolithic to the Bronze age with the giant limpets (Cymbula safiana and Patella ferruginea) being present since MIS6. To assess their distribution, predominance, and cultural significance this paper presents the results from an exhaustive archeozoological survey of the southern Iberian region. A total of 1628 specimens have been analysed, including 425 modern (333 C. safiana and 91 P. ferruginea) and 1203 from 60 archaeological deposits deriving from 36 sites, both coastal and continental. Giant limpets’ context also has been described and it has been related with a wide variety of deposits ranging from food refuse accumulations to occupations and burials.
Detailed morphological and surface analysis allowed us to determine extraction methods and anthropic transformations. On coastal sites, the giant limpet record starts with Neanderthal populations from the Middle Palaeolithic and continues throughout the Upper Palaeolithic, Mesolithic, Neolithic, and Copper Age. On inland sites, giant limpets appear first in reduced numbers during the Late Neolithic and have been often worked into elliptical contours with polished, rib-free, external shell surfaces. In this study, we focus on the Copper Age, when giant limpet use becomes common, and records include tholoi, dolmens and other funerary contexts. The data indicate that the use of P. ferruginea is associated with Los Millares and El Argar cultures. Giant limpets use declines during the Bronze Age probably due to the major cultural shift that occurred during the Chalcolithic to Bronze transition.
The data suggest that giant limpets should be considered as proxies of long-range trade during the Chalcolithic. We propose a new hypothesis linking giant limpets symbology with orbital/tidal variations and the ubiquitous use of marine elements as symbolism during this period.
Our study highlights the relevance of shells in the reconstruction of the symbolic evolution of prehistoric cultures, as well as their connections with local ecosystem resources and regional commerce networks.
•Ecology, exploitation, and potential symbolism of giant limpets found in archaeological sites in southern Iberia. They include data on modern specimens to strengthen their analysis. Works on molluscs in archaeology generally focus on.•Species used mainly as food or for ornaments. In this work we focus on underrepresented species: the giant limpets and the relationship of the cultures of southern Iberia with this resource.•We believe that the data provided is novel and provides a new vision of archaeomalacology.
Atlantic bluefin tuna (Thunnus thynnus; BFT) is a large (up to 3.3 m in length) pelagic predator which has been exploited throughout the eastern Atlantic and Mediterranean since prehistoric times, as ...attested by its archeological remains. One key insight derivable from these remains is body size, which can indicate past fishing abilities, the impact of fishing, and past migration behavior. Despite this, there exists no reliable method to estimate the size of BFT found in archeological sites. Here, 13 modern Thunnus spp. skeletons were studied to provide power regression equations that estimate body length from vertebra dimensions. In modern specimens, the majority of BFT vertebrae can be differentiated by their morphological features, and thus, individual regression equations can be applied for each rank (position in vertebral column). In an archeological context, poor preservation may limit one's ability to identify rank; hence, “types” of vertebrae were defined, which enable length estimates when rank cannot be determined. At least one vertebra dimension, height, width, or length correlated highly with body length when vertebrae were ranked (R2 > 0.97) or identified to types (R2 > 0.98). Whether using rank or type, length estimates appear accurate to approximately ±10%. Finally, the method was applied to a sample of Roman‐era BFT vertebrae to demonstrate its potential. It is acknowledged that further studies with larger sample sizes would provide more precision in BFT length estimates.
► Influence of FA composition on sunflower oil performance was clarified using selected samples. ► Polymer formation followed zero-order kinetics independently of oil composition. ► There were no ...significant differences between frying oils and oils extracted from fried potatoes. ► The use of thermal oxidation assays to determine frying performance is demonstrated.
The influence of fatty acid composition on formation of new compounds at frying temperatures has been studied in seven samples of sunflower oils widely differing in their fatty acid composition. Thermal oxidation assays as well as frying experiments were carried out and samples were evaluated by measuring the new compounds formed, i.e. polymers, polar compounds and their distribution by molecular weight, and polar fatty acids and their distribution by molecular weight. The levels of all the new compounds analysed strongly depended on the degree of oil unsaturation; the two least unsaturated oils with low content of linoleic acid and high content of palmitic acid behaved exceptionally well. When considering polar compounds or polar fatty acids, the polymers/oxidised monomers ratio increased significantly as the level of degradation increased. The new compounds formed are practically identical when analysed in the used frying oils or in the lipids extracted from the counterpart fried potatoes, independently of the level of degradation.
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