1,928 research outputs found
Impact of myxomatosis on densities of Iberian hares (Lepus granatensis) in North-western Spain: implications for management and sustainable hunting
[ENG]Outbreaks of myxomatosis in Iberian hares (Lepus granatensis) were detected for the first time in Spain in 2018. The disease spread to a significant proportion of the species range, negatively affecting the hare populations. In this study, we analyzed the impact of myxomatosis at hunting grounds of Castilla y León (Northern Spain), comparing hare density during two consecutive hunting seasons; the first when outbreaks were detected for the first time (season 1, Oct 2019-Jan 20) and the second after the spread of the disease (season 2, Oct 2020-Jan 21). Data was gathered from 1,102 hunts from 178 hunting grounds through “coursing”, a hunting type in which hunters and greyhounds search for hares, allowing the estimation of hare density. Overall, hare density decreased significantly, from 12.7 hare/100 ha in season 1 to 4.7 hare/100 ha in season 2. The percentage of hares suspected to be affected by myxomatosis (sick and dead) per hunt was higher in season 1 (14.4%) compared to season 2 (10.7%). For both seasons, this proportion was higher when hunting season was started (20.7%, October), compared to the remaining months (4.7%, November–January). However, the proportion of hunting grounds affected increased from 44% in season 1 to 66.7% in season 2. Our research confirmed a 62.7% reduction in hare density in Castilla y León after the spread of myxomatosis and identified scenarios of possible depletion when densities were below 4–5 hare/100 ha. As myxomatosis becoming endemic in Iberian hares is likely, hunters and game managers should continue current monitoring and disease surveillance and make management decisions accordingly.SIJunta de Castilla y LeónFundación Artemisa
Critical incidents which limit performance of Chilean University rowers who won a medal in the Pan American Games of Lima 2019
Main objective of this study was to provide a basis for the comprehension of the main critical incidents (i.e. obstacles) that Chilean rowers who were medallists in the Pan American Games of Lima 2019 have to face within the academic, socioeconomic and sports processes. 19 athletes were selected through a non-probabilistic sampling. A content validated questionnaire and an in-deep interview were used. Higher levels of consistency were observed. Through the inferential analysis (ANOVA) it was possible to conclude that athletes are concerned with some academic and social crisis within their sporting career. This fact does not allow them to concentration and integral tranquillity to be focused and achieve proper results in academic and sports areas. Results presented in this study may contribute to the improvement of public policies and, specifically, contingency and innovation plans for improvement within higher education institutions. This study is framed within the context of social transformation that Chile is currently living.Agencies: Chilean Rowing Federation; Chilean Olympic Committee
Selection of best conditions of inoculum preparation for optimum performance of the pigment production process by Talaromyces spp. using the Taguchi method
Process optimisation techniques increasingly need to be used early on in research and development of processes for new ingredients. There are different approaches and this article illustrates the main issues at stake with a method that is an industry best practice, the Taguchi method, suggesting a procedure to assess the potential impact of its drawbacks. The Taguchi method has been widely used in various industrial sectors because it minimises the experimental requirements to define an optimum region of operation, which is particularly relevant when minimising variability is a target. However, it also has drawbacks, especially the intricate confoundings generated by the experimental designs used. This work reports a process optimisation of the synthesis of red pigments by a fungal strain, Talaromyces spp. using the Taguchi methodology and proposes an approach to assess from validation trials whether the conclusions can be accepted with confidence. The work focused on optimising the inoculum characteristics, and the studied factors were spore age and concentration, agitation speed and incubation time. It was concluded that spore age was the most important factor for both responses, with optimum results at 5 days old, with the best other conditions being spores concentration, 100,000 (spores/mL); agitation, 200 rpm; and incubation time, 84 h. The interactive effects can be considered negligible and therefore this is an example where a simple experimental design approach was successful in speedily indicating conditions able to increase pigment production by 63% compared to an average choice of settings
QoSatAr: a cross-layer architecture for E2E QoS provisioning over DVB-S2 broadband satellite systems
This article presents QoSatAr, a cross-layer architecture developed to provide end-to-end quality of service (QoS) guarantees for Internet protocol (IP) traffic over the Digital Video Broadcasting-Second generation (DVB-S2) satellite systems. The architecture design is based on a cross-layer optimization between the physical layer and the network layer to provide QoS provisioning based on the bandwidth availability present in the DVB-S2 satellite channel. Our design is developed at the satellite-independent layers, being in compliance with the ETSI-BSM-QoS standards. The architecture is set up inside the gateway, it includes a Re-Queuing Mechanism (RQM) to enhance the goodput of the EF and AF traffic classes and an adaptive IP scheduler to guarantee the high-priority traffic classes taking into account the channel conditions affected by rain events. One of the most important aspect of the architecture design is that QoSatAr is able to guarantee the QoS requirements for specific traffic flows considering a single parameter: the bandwidth availability which is set at the physical layer (considering adaptive code and modulation adaptation) and sent to the network layer by means of a cross-layer optimization. The architecture has been evaluated using the NS-2 simulator. In this article, we present evaluation metrics, extensive simulations results and conclusions about the performance of the proposed QoSatAr when it is evaluated over a DVB-S2 satellite scenario. The key results show that the implementation of this architecture enables to keep control of the satellite system load while guaranteeing the QoS levels for the high-priority traffic classes even when bandwidth variations due to rain events are experienced. Moreover, using the RQM mechanism the user’s quality of experience is improved while keeping lower delay and jitter values for the high-priority traffic classes. In particular, the AF goodput is enhanced around 33% over the drop tail scheme (on average)
Perstraction of intracellular pigments through submerged fermentation of Talaromyces spp. in a surfactant rich media: a novel approach for enhanced pigment recovery
A high percentage of the pigments produced by Talaromyces spp. remains inside the cell, which could lead to a high product concentration inhibition. To overcome this issue an extractive fermentation process, perstraction, was suggested, which involves the extraction of the intracellular products out of the cell by using a two-phase system during the fermentation. The present work studied the effect of various surfactants on secretion of intracellular pigments produced by Talaromyces spp. in submerged fermentation. Surfactants used were: non-ionic surfactants (Tween 80, Span 20 and Triton X-100) and a polyethylene glycerol polymer 8000, at different concentrations (5, 20, 35 g/L). The highest extracellular pigment yield (16 OD500nm) was reached using Triton X-100 (35 g/L), which was 44% higher than the control (no surfactant added). The effect of addition time of the selected surfactant was further studied. The highest extracellular pigment concentration (22 OD500nm) was achieved when the surfactant was added at 120 h of fermentation. Kinetics of extracellular and intracellular pigments were examined. Total pigment at the end of the fermentation using Triton X-100 was 27.7% higher than the control, confirming that the use of surfactants partially alleviated the product inhibition during the pigment production cultur
A systematic review on the muscular activation on the lower limbs with five different variations of the deadlift exercise
The deadlift is one of the most widely used resistance exercises by different types of trainees and with different aims including aesthetics, performance and health. There are numerous variations of the deadlift exercise which have different effects on the exercise biomechanics and muscular activation. The main objective of this research was to systematically review the literature looking forward to gathering data on the muscular activation on the lower limbs with different variations of the deadlift exercise (conventional, sumo, Romanian, straight legs and hex-bar). 19 articles met the inclusion criteria and were included in the analysis. Quality of the articles was assessed through the PEDro scale. Main findings were that deadlift is a posterior-chain dominant exercise. Changes in activation between the variations majorly depend on the hip flexion in relation to the knee flexion. For instance, the straight-legs deadlift does not involve knee flexion and mainly activates hip extensors. Other factors such as the distance between the load and the centre of mass, the knee flexion planes, or the total intensity also condition the muscular activation. For example, the hex-bar deadlift allows the subject being in alignment with the load and performing the exercise with relatively vertical back, which provokes an increase on the activation of the knee extensors. In conclusion, this study may help the strength and conditioning professionals and practitioners with the exercise selection depending on the muscular targets and the individual characteristics of the athlete
Optimising the Performance of CO2-Cured Alkali-Activated Aluminosilicate Industrial By-Products as Precursors
Three industrial aluminosilicate wastes were studied as precursors to produce alkali-activated concrete: (i) electric arc furnace slag, (ii) municipal solid waste incineration bottom ashes, and (iii) waste glass rejects. These were characterized via X-ray diffraction and fluorescence, laser particle size distribution, thermogravimetric, and Fourier-transform infrared analyses. Distinctive combinations of anhydrous sodium hydroxide and sodium silicate solution were tried by varying the Na2O/binder ratio (8%, 10%, 12%, 14%) and SiO2/Na2O ratio (0, 0.5, 1.0, 1.5) to find the optimum solution for maximized mechanical performance. Specimens were produced and subjected to a three-step curing process: (1) 24 h thermal curing (70 °C), (2) followed by 21 days of dry curing in a climatic chamber (~21 °C, 65% RH), and (3) ending with a 7-day carbonation curing stage (5 ± 0.2% CO2; 65 ± 10% RH). Compressive and flexural strength tests were performed, to ascertain the mix with the best mechanical performance. The precursors showed reasonable bonding capabilities, thus suggesting some reactivity when alkali-activated due to the presence of amorphous phases. Mixes with slag and glass showed compressive strengths of almost 40 MPa. Most mixes required a higher Na2O/binder ratio for maximized performance, even though, contrary to expectations, the opposite was observed for the SiO2/Na2O ratio
Incidence and prevalence of injuries in futsal: A systematic review of the literature
Futsal athletes are exposed to a high number of injures. Purpose: This study aimed to gather data on the injures produced in futsal, attending to the prevalence, part of the body injured, type of injury and mechanism, and severity. Also, to evaluate the influence that sociodemographic factors and the position on the pitch may have on the injuries. Finally, we pursued to summarize the prevention strategies proposed by the expert literature. Design: Different search strategies were entered in PubMed, Scopus, Web of Science, and Sport Discuss databases. Results: 36 articles were selected to be reviewed. Futsal is situated among the sports with the highest injury incidence, being the main body part injured the lower limb, specifically the knees and ankles. Regarding the type of injury and the mechanism causing the injury, bone injuries are usually related to contact with rivals and muscle, tendon, and ligament injuries related to non-contact mechanisms. In this concern, non-contact injuries are frequently more severe than impact injuries. There is not a clear consensus on if more injuries occur in training or games, and on the severity of the major part of the injuries that occur in futsal. Concerning sex, male players seem to present a higher prevalence of ankle injuries while woman players present more incidence of knee sprains. The age was reported to be correlated with the incidence of injuries during futsal practice. No influence of the position on the field of play on the prevalence of injuries was observed in the literature. Some recommendations are gathered concerning the prevention of injuries. These recommendations are focused on player equipment, playing facilities, rules, physical assessment, and appropriate strength and conditioning preparation. Conclusion: The results presented in this study may help coaches and practitioners to understand crucial factors on the common injuries that occur in futsal. This may allow them to prevent potential injuries and maintain the athlete’s performance
Phospho-kinase profile of triple negative breast cancer and androgen receptor signaling
BACKGROUND: The androgen receptor (AR) plays a central role in the oncogenesis of different tumors, as is the case in prostate cancer. In triple negative breast cancer (TNBC) a gene expression classification has described different subgroups including a luminal androgen subtype. The AR can be controlled by several mechanisms like the activation of membrane tyrosine kinases and downstream signaling pathways. However little is known in TNBC about how the AR is modulated by these mechanisms and the potential therapeutic strategists to inhibit its expression. METHODS: We used human samples to evaluate the expression of AR by western-blot and phospho-proteomic kinase arrays that recognize membrane tyrosine kinase receptors and downstream mediators. Western-blots in human cell lines were carried out to analyze the expression and activation of individual proteins. Drugs against these kinases in different conditions were used to measure the expression of the androgen receptor. PCR experiments were performed to assess changes in the AR gene after therapeutic modulation of these pathways. RESULTS: AR is present in a subset of TNBC and its expression correlates with activated membrane receptor kinases-EGFR and PDGFRβ in human samples and cell lines. Inhibition of the PI3K/mTOR pathway in TNBC cell lines decreased notably the expression of the AR. Concomitant administration of the anti-androgen bicalutamide with the EGFR, PDGFRβ and Erk1/2 inhibitors, decreased the amount of AR compared to each agent given alone, and had an additive anti-proliferative effect. Administration of dihydrotestosterone augmented the expression of AR that was not modified by the inhibition of the PI3K/mTOR or Erk1/2 pathways. AR expression was posttranscriptionally regulated by PI3K or Erk1/2 inhibition. CONCLUSION: Our results describe the expression of the AR in TNBC as a druggable target and further suggest the combination of bicalutamide with inhibitors of EGFR, PDGFRβ or Erk1/2 for future development
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