115 research outputs found
Population synthesis of isolated Neutron Stars with magneto--rotational evolution
We revisit the population synthesis of isolated radio-pulsars incorporating
recent advances on the evolution of the magnetic field and the angle between
the magnetic and rotational axes from new simulations of the magneto-thermal
evolution and magnetosphere models, respectively. An interesting novelty in our
approach is that we do not assume the existence of a death line. We discuss
regions in parameter space that are more consistent with the observational
data. In particular, we find that any broad distribution of birth spin periods
with s can fit the data, and that if the alignment angle is
allowed to vary consistently with the torque model, realistic magnetospheric
models are favoured compared to models with classical magneto-dipolar radiation
losses. Assuming that the initial magnetic field is given by a lognormal
distribution, our optimal model has mean strength with width .
However, there are strong correlations between parameters. This degeneracy in
the parameter space can be broken by an independent estimate of the pulsar
birth rate or by future studies correlating this information with the
population in other observational bands (X-rays and -rays).Comment: 10 pages, 9 figures, submitted and accepted to MNRAS, comments
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Electrocatalysis on shape-controlled metal nanoparticles: Progress in surface cleaning methodologies
The use of shape-controlled metal nanoparticles has produced not only a clear enhancement in the electrocatalytic activity of different reactions of interest but also a better understanding of the effect of the surface structure on nanoscaled materials. However, it is well-accepted that a correct understanding of the correlations between shape/surface structure and electrochemical reactivity indispensably requires the use of clean surfaces. In this regard, and considering that most of the synthetic methodologies available in the literature for the preparation of these shaped metal nanoparticles employ capping agents, the development of effective surface cleaning methodologies able to remove such capping agents from the surface of the corresponding nanoparticles, becomes an extremely important prerequisite to subsequently evaluate their electrocatalytic properties for any reaction of interest. Consequently, in this contribution, we summarize the most relevant advances about surface cleaning procedures applied to different shaped metal nanoparticles for electrocatalytic purposes. It is worth mentioning that this work will only include contributions in which the surface cleanness of the samples is specifically evaluated using well-established electrochemical tools.This work has been financially supported by the MINECO of Spain through project CTQ2013-48280-C3-3-R. JSG acknowledges financial support from VITC (Vicerrectorado de Investigación y Transferencia de Conocimiento) of the University of Alicante
Opinion of the Spectators of a Grand Tour in Spain: A Qualitative Analysis
The objective of this study is to carry out a qualitative analysis of the ratings of tourists and residents attending the road cycling sporting event "La Vuelta" held in Spain in 2019, 2020 and 2021 editions. Methods: The sample consisted of 1,203 comments/observations from tourists and residents in the in situ and post-event phase of each edition. For this qualitative analysis, an open question was used at the end of a quantitative questionnaire on social and tourism impact. Once each comment had been categorised, a summary was made of the responses and frequencies of each idea according to each category, positive and negative comments and the words most used in each type of comment. Nvivo v.10 software (QSR International, Burlington, MA 01803, USA) was used to analyse the comments and frequencies of each idea. Results: Most of the positive comments focus on the positive feelings and emotions generated by attending the event (emotion or enjoyment; 12.4%), great experience (14.8%), atmosphere of the event (10.4%), good organisation of the event (12.1%) and future intentions to return and recommend the event (7.4%). Negative comments mainly refer to the COVID-19 pandemic (11.8%), the advertising caravan (7.4%) and traffic and parking problems (5.9% of comments). Among the words associated with negative comments, the word "advertising caravan" stands out, while the most used words in positive reviews were "experience" and "emotion". Conclusion: Most of the positive comments focus on positive feelings and emotions generated by attending the event (emotion or enjoyment) and the great experience and atmosphere surrounding the sporting event. In the 2020 edition, the COVID-19 pandemic negatively affected the event, although parking problems and traffic congestion are the worst-rated categories
对电子竞技赛事中观众对游客的感知的评估
eSports events are a great tourist attraction for event organizations, for this reason, the objective of the study is to analyse the tourist impact of the eSports event “Iberian Cup 2019”. The sample consisted of 390 participants who attended the tournament in the city of Barcelona. The instrument used was a questionnaire that analyses the tourism impact in sport events. In relation to the results, the variables “Emotion-Environment” obtained a greater correlation and the variable “personal of the event” was the best evaluated. The attendees had a good satisfaction of the event and future intentions, being the intention to return in the future to the city of Barcelona the best valued item. Finally, the attendees who did physical activity valued most of the parameters analysed better, finding significant differences between the group that does not do physical activity. These results are useful to create strategies to attract more tourists in future events.eSports events are a great tourist attraction for event organizations, for this reason, the objective of the study is to analyse the tourist impact of the eSports event “Iberian Cup 2019”. The sample consisted of 390 participants who attended the tournament in the city of Barcelona. The instrument used was a questionnaire that analyses the tourism impact in sport events. In relation to the results, the variables “Emotion-Environment” obtained a greater correlation and the variable “personal of the event” was the best evaluated. The attendees had a good satisfaction of the event and future intentions, being the intention to return in the future to the city of Barcelona the best valued item. Finally, the attendees who did physical activity valued most of the parameters analysed better, finding significant differences between the group that does not do physical activity. These results are useful to create strategies to attract more tourists in future events.Электронные спортивные мероприятия являются большой туристической достопримечательностью для организаторов мероприятий, поэтому целью исследования является анализ туристического воздействия электронного спортивного мероприятия «Кубок Иберии 2019». Выборка состояла из 390 участников, которые присутствовали на турнире в Барселоне. В качестве инструмента использовался вопросник, который анализировал влияние туризма на спортивные мероприятия. По сравнению с результатами, переменные «эмоции-окружение» получили большой уровень корреляции, а переменная «персонал мероприятия» была оценена наилучшим образом. Лучше всего оценивалось измерение мероприятия: «я в восторге от мероприятия», за которым следовало «наличие интересных мест для посещения в городе» по отношению к имиджу места назначения. Участники мероприятия остались довольны мероприятием и намерениями на будущее. Наконец, участники, которые были физически активны, добились значительных успехов. Эти результаты полезны для создания стратегий привлечения большего количества туристов на будущих мероприятиях.电子体育赛事可以为赛事组织城市带来巨大的旅游吸引力,因此,本研究的目的是分析“2019年伊比利亚杯”电子竞技赛事对旅游的影响。样本包括390位参加了巴塞罗那市比赛的选手。研究使用工具为一份用于分析体育赛事中的旅游影响的问卷。结果表明,有关“情绪-环境”的变量具有较高的相关性,“赛事人员”变量获得最积极评估。评分最高的赛事维度是“我对赛事举办感到兴奋”,其次是与目的地图片有关的“在参观的城市中有有趣的地方”。参与者对活动和未来的打算非常满意。最终显示,进行体育锻炼的参与者表现出显着性差异。这些结果有助于在将来活动中制定吸引更多游客的策略
Localización y registro de canoas monóxilas en el río Magdalena y ciénagas adyacentes (Colombia): metodología y avances de una expedición científica contemporánea
Magdalena River has been the main channel of communication between the Colombian continental interior and the maritime dynamics of the Caribbean coast, from the pre-Hispanic period to at least early 20th century. Its large basin was the scenario of an extraordinary nautical dynamism, whose technological base has been predominantly the dugout canoe. Consequently, this article exposes the preliminary advances of an investigation on the ground, raised in a transdisciplinary way by combining views and methods of ethnohistory, ethnography and nautical archeology, whose objectives were related to the analysis of that river navigation that connected territories, goods, people and ideas; the evaluation of possible conceptual and constructive continuities in the canoes still present in the river, and the recording of the artisan knowledge of the communities that still today navigate its waters and populate its banks.El río Magdalena ha sido la principal vía de comunicación entre el interior continental colombiano y las dinámicas marítimas del litoral caribe, desde el periodo prehispánico hasta al menos inicios del siglo XX. Su amplia cuenca es testigo de un extraordinario dinamismo náutico basado de forma predominante en la canoa monóxila. En consecuencia, el presente artículo expone los avances preliminares de una investigación sobre el terreno, planteada de forma transdisciplinar al combinar miradas y métodos de etnohistoria, etnografía y arqueología náutica, cuyos objetivos estuvieron relacionados con el análisis de esa navegación fluvial que conectó territorios, mercancías, personas e ideas; la evaluación de posibles continuidades conceptuales y constructivas en las embarcaciones aun presentes en el río, y el registro del saber artesanal de las comunidades que aún hoy navegan sus aguas y pueblan sus riberas
Fan’s perspective on professional leagues and sporting events during COVID-19 confinement period
The restriction imposed by COVID-19 pandemic has caused a great social change in the world and has affected many sectors, including the sport industry by having an impact and altering the normal development of the sport competitions and events. Therefore, it is fundamental to know sport fans’ opinions about the professional championships during the confinement period. The sample is composed by 1025 professional sports leagues fans and major sporting events celebrated in Spain, with people in the age range 18-70. The instrument used to collect data was an adaptation of the American questionnaire designed by Seton Hall University. The results show that 55% of fans thought that sport leagues and events were cancelled on time. Furthermore, 92.8% of the survey respondents would not attend a live match without social distancing measures or without the existence of a vaccine; 67.4% would follow it through mass media resources with the same interest. The population group under 25 feels safe attending sports leagues or events (9.7%). These results might help to take decisions based on preventive measures to guarantee security within the sport context
Deep eutectic solvents as a green tool for the extraction of bioactive phenolic compounds from avocado peels
The following are available online at https://www.mdpi.com/article/10.3390/molecules27196646/s1, Figure S1: Example of a chromatogram of some identified com pounds at 280 nm from the studied avocado peel extracts; Table S1: Pearson’s correlation coefficients for the total phenolic content (TPC), total flavonoid content (TFC) and antioxidant capacity (FRAP and AAT) of different extracts from avocado peel. Significant correlations are marked in bold.Avocado peels are the main agro-industrial residue generated during the avocado processing, being a rich source of bioactive compounds like phenolic compounds. The growing demand for more sustainable processes requires the development of new and effective methods for extracting bioactive compounds from industrial waste. Deep eutectic solvents (DESs) are a new sustainable alternative to toxic organic solvents due to their non-toxicity and biocompatibility. In this study, five selected DESs were applied for the extraction of bioactive phenolic compounds from avocado peels. The extraction efficiency was evaluated by measuring the total phenolics and flavonoids content. The best extraction results were obtained with choline chloride-acetic acid and -lactic acid (92.03 ± 2.11 mg GAE/g DAP in TPC and 186.01 ± 3.27 mg RE/g DAP); however, all tested DESs show better extraction efficiency than ethanol. All the obtained NADES extracts have high antioxidant activity (FRAP: 72.5–121.1 mg TE/g; TAC: 90.0–126.1 mg AAE/g). The synthesized DESs and avocado peels DES extracts had activity against all tested bacteria (Staphylococcus aureus, Streptococcus dysgalactiae, Escherichia coli and Pseudomonas putida), and the extracts prepared with choline chloride-acetic acid and -lactic acid have the highest antibacterial activity against all microorganisms. These results, coupled with the non-toxic, biodegradable, low-cost, and environmentally friendly characteristics of DESs, provide strong evidence that DESs represent an effective alternative to organic solvents for the recovery of phenolic bioactive compounds from agro-industrial wastes.This study was supported by the Portuguese Foundation for Science and Technology (FCT)
under the scope of the strategic funding of UIDB/04469/2020 unit, and by LABBELS—Associate
Laboratory in Biotechnology, Bioengineering and Microelectromechanical Systems, LA/P/0029/2020.
B. Gullón would like to express its gratitude to the Spanish Ministry of Science, Innovation and Uni versities for financial support (grant reference RYC2018-026177-I). Authors are grateful to MINECO
(Spain) for the financial support of this work in the framework of the project “Cutting-edge strategies
for a sustainable biorefinery based on valorization of invasive species” with reference PID2019-
110031RB-I00 and to Consellería de Cultura, Educación e Ordenación Universitaria (Xunta de Galicia)
through the contract ED431C 2017/62-GRC to Competitive Reference Group BV1, programs partially
funded by FEDER.info:eu-repo/semantics/publishedVersio
Optimization of ultrasound-assisted extraction of phenolic compoundsfrom avocado peels
Avocado (Persea americana Mill.), a fruit native to Central America and Mexico, is one of the most consumed fruits in the world, with a global production of approximately 6.3 million tonnes in 2018. Its industrial processing generates significant amounts of by-products, mainly peels, seeds, or exhausted pulp, which disposal causes important environmental and economic problems. Nevertheless, these by-products present a high content of bioactive molecules with many human health benefits, which could be used for the formulation of functional foods or cosmetic products (Del Castillo-Llamosas et al., 2021; Rodríguez-Martínez et al., 2021). One of the important challenges for the recovery of added-value molecules from agro-industrial wastes is the selection of extraction technologies leading to high extraction efficiency and helping to preserve the quality of the recovered molecules. In this framework, ultrasound-assisted extraction (UAE) has been considered a green technology for the isolation of bioactive compounds from several natural sources.
The purpose of the present study was to optimize the extraction of antioxidants from avocado peel (AP) using
ultrasounds. The influence of ethanol/water ratio and time was evaluated using response Surface methodology (RSM).
Under selected operational conditions (38.46% ethanol and 44.06 min), the response values were 45.34 mg GAE/g dried AP and 87.56 mg RE/g dried AP for TPC and TFC, respectively, with antioxidant levels of 73.25, 160.34 and 44.65 mg TE/g dried AP as determined by the DPPH, ABTS and FRAP methods, respectively.
In addition, the optimized extracts were chemically characterized by HPLC-ESI-MS and FTIR. The main the phenolic compounds found in the avocado peel extract were phenolic acids, such as hydroxybenzoic and hydroxycinnamic acids.The authors acknowledge the financial support received from “Xunta de Galicia” (GRC ED431C 2017/62-GRC, and Project ED431F 2020/03). These projects are partially funded by the FEDER Program of the European Union (“Unha maneira de facer Europa”). Beatriz Gullón would like to express her gratitude to the Spanish Ministry of Economy and Competitiveness for her postdoctoral grant (Reference RYC2018-026177-I).info:eu-repo/semantics/publishedVersio
Assessment of prebiotic potential of Akpan-yoghurt-like product and effects on the human intestinal microbiota
The effect of Akpan (yoghurt-like product) consumption on the human intestinal microbiota was examined. The prebiotic potential of Akpan was assessed by in vitro fermentation using, as inocula, individual probiotic strains and faecal samples from three healthy donors. In this latter case, the prebiotic activity was assessed through the quantification of short chain fatty acid (SCFA) production, the evolution of the pH and the evaluation of dynamic bacterial population by fluorescent in situ hybridization (FISH). Results demonstrated that Akpan was metabolized after 44 h of fermentation, exerting a prebiotic effect, similar to that observed for fructooligosaccharides (FOS). All the considered bacterial groups significantly increased after Akpan and FOS fermentation. Under the tested conditions, no significant differences between the SCFA concentration produced by Akpan and FOS after of incubation were detected. Our findings contribute to support the utilization of Akpan as a functional food with potential beneficial effects on gastrointestinal healthThis study was financially supported by the European Seven Framework programme (EU FP7), and is part of the AFTER project (African Food Tradition Revisited by Research) under contract no. 245-025. It was also supported by National Funds from FCT – Fundação para a Ciência e a Tecnologia – through project PEst-OE/EQB/LA0016/2013. B. Gullón is grateful to the Portuguese Foundation for Science and Technology (Fundação para a Ciência e Tecnologia, FCT, Portugal) for funding through the postdoctoral fellowship reference SFRH/BPD/79941/2011S
Optical Temperature Sensor Capabilities of the Green Upconverted Luminescence of Er3+ in La3NbO7 Ceramic Powders
We present a study of the Er3+ upconverted luminescence in erbium doped Lanthanum
Niobium Oxide, La3NbO7, ceramic powder, prepared by solid state reaction. This study focuses
on the analysis of the feasibility of this system as a temperature sensor. Efficient UC luminescence
was observed under the 975 nm excitation showing intense green, red and NIR (850 nm) emission
bands. The NIR luminescence centred at about 850 nm and lying on the first biological window is
mainly insensitive to the temperature. In contrast, the upconverted green bands, associated with
the (2H11/2,4S3/2) !4I15/2 transitions, showed a high sensibility to temperature. Their temperature
dependence was studied from RT up to 525 K, paying special attention to the physiological range of
temperature (303–318 K). The high thermal sensitivities obtained, in comparison with other Er3+ and
Er3+-Yb3+ based optical temperature sensors in such ranges, suggest the potential application of this
phosphor in thermal sensing, suitable for both biological systems and other industrial applications
requiring higher temperatures.This research has been partially supported by the Spanish Ministerio de Ciencia, Innovación
y Universidades (MICINN) through the Spanish projects RTI2018-101020-B-100 and PID2019-
106383GB-C44, by the Madrid Government (Comunidad de Madrid-Spain) under the Multiannual
Agreement with UC3Min the line of Excellence of University Professors (EPUC3MXX) and in the context
of the V PRICIT (Regional Programme of Research and Technological Innovation) by the Agencia
Canaria de Investigación, Innovación y Sociedad de la Información (ACIISI) (ProID2017010078).
M.A.H.-R. thanks MINECO for the FPI grant (BES-2014-068666). U.R.R.-M.
thanks Gobierno de Canarias and EU-FEDER for grant ProID2020010067
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