Black boxes in analytical chemistry： University students misconceptions of instrumental analysis     

Antonio Domenech Carbo  Jose Vicente Gimeno Adelantado Francisco Bosch Reig 《美中教育评论》2010,7(7):15-29

Misconceptions of chemistry and chemical engineering university students concerning instrumental analysis have been established from coordinated tests, tutorial interviews and laboratory lessons. Misconceptions can be divided into： （1） formal, involving specific concepts and formulations within the general frame of chemistry; （2） operational/topical, dealing with specific capabilities, problems and operations in chemistry; （3） methodological, associated to peculiar methods of analytical chemistry and data treatment; and （4） social, regarding the relation of analytical data with the social frame. Such misconceptions define a non-structured view of analytical methods, procedures and protocols related with analytical instrumentation. Instruments are frequently viewed as an autonomous, error-free black box providing non-structured data with no need of calibration or control, whereas weak relationships are established between data and aims along the analytical process.  相似文献   

The returns to UK degrees for foreign‐educated graduates          下载免费PDF全文

Javier Valbuena  Yu Zhu 《British Educational Research Journal》2018,44(3):440-462

Exploiting information on foreign qualifications for the first time, we estimate the returns to obtaining UK higher degrees for foreign graduates who migrated to the UK in their 20s. Accounting for direct measures of foreign and UK qualifications and country‐of‐origin fixed effects, we find substantial returns to obtaining UK (higher) degrees on hourly wages and occupational attainment for both genders, working mainly through occupational attainment. However, there is strong evidence that the effect of the high returns is driven by immigrants from countries where English is not a dominant language. Moreover, returns to UK (higher) degrees are more pronounced for graduates from low‐HDI/GDP countries, suggesting an important role for the incompatibility of education and skills between home and destination countries. We further examine the robustness of our results by using a partial identification method, and our findings suggest that the extent of selection on unobservables required to eliminate a positive treatment effect is too large to be plausible, especially for men. Our study extends previous research with the first evidence from the UK, by showing large positive effects of post‐migration investments in human capital acquisition on labour market outcomes. Obtaining UK higher degrees appears to reduce the informational uncertainty associated with foreign credentials, facilitate cultural and economic assimilation, and boost economic opportunities for foreign graduates, especially for those developing/poor country immigrants.  相似文献   

Group characteristics and profiles of shared regulation in collaborative environments involving asynchronous communication / Características y perfiles grupales de regulación compartida en entornos colaborativos de comunicación asíncrona     

Juan-Carlos Castellanos  Javier Onrubia 《Infancia y Aprendizaje》2018,41(2):369-414

The processes of socially shared regulation in small groups of students who perform collaborative tasks through forums involving asynchronous communication are explored in this article. The specific aim of the study is to identify profiles of shared regulation in groups of students who have different performance levels on the task, depending on the regulatory activities exercised by the groups and their distribution over time. For that purpose, a case study was developed; six small groups of university students collaboratively performed a complex task (for 29 days) in a virtual environment based on asynchronous discussion forums. The results revealed three different profiles: (i) a profile with stable and high regulation; (ii) a profile with partially stable and medium regulation; and (iii) a profile with unstable and low regulation. The first two profiles were observed in the groups with high performance levels on the task, while the third profile was observed in the low-performing groups. Therefore, some recommendations are suggested to support processes of shared regulation in asynchronous collaborative learning situations.  相似文献   

Stimulus space complexity determines the ratio of specialist and generalist neurons during pattern recognition     

Aaron Montero  Ramon Huerta  Francisco B. Rodriguez 《Journal of The Franklin Institute》2018,355(5):2951-2977

Neural processing layers built on divergent connectivity patterns display two types of stimulus-dependent responses: neurons that react to a few stimuli, specialists, and other ones that respond to a wide range of inputs, generalists. Specialists are essential for the discrimination of stimuli and generalists extract common and generic properties from them. This neural heterogeneity could have emerged because of animal adaptation to the environment. Thus, we suggest that there is a relationship between the percentage of specialists and generalists and the stimulus complexity. In order to study this possible relationship, we use patterns with different complexities in a bio-inspired neural network and calculate their classification errors for different ratios of these types of neurons. This study shows that, when the complexity of the stimuli is low, the minimum classification error is achieved with almost any specialist-generalist ratio. Thus, in this case, the role of these neurons during pattern recognition is unspecific. When this complexity is intermediate, both are needed to minimize the classification error, usually in a similar proportion. For increasing stimulus complexity, the importance of generalists decreases, until their relevance is fully nullified when the complexity is high. Therefore, if we adjust the specialist-generalist ratio to the complexity of patterns, we can build more effective neural networks for pattern recognition. Finally, we propose an estimation of stimulus complexity based on the proportion of these types of neurons observed by neural recordings. This offers the possibility to evaluate the stimulus complexity to which animals are adapted.  相似文献   

Construction and validation of a classroom climate scale: a mixed methods approach     

Verónica López  Javier Torres-Vallejos  Paula Ascorra  Boris Villalobos-Parada  Marian Bilbao  René Valdés 《Learning Environments Research》2018,21(3):407-422

Students’ perceptions of their classroom climate have been found to relate significantly to students’ learning outcomes. The purpose of the present study was to construct an instrument for assessing elementary-school students’ perceptions of classroom climate, based on a previous instrument that was being used in Chile by a public national school mental health program as a tool for aiding teachers in improving classroom management, but which showed poor psychometric properties. We used a six-staged mixed-methods approach to construct relevant items and dimensions based on this measure and by adapting previously-existing scales. Item development included participatory construction of items involving program officials, focus groups with students, and a pilot study. The final version was administered to a sample of 6813 elementary-school students. Results showed adequate reliability and construct validity, convergent validity with school climate, and divergent validity with peer victimisation. When consequential validity was explored through semi-structured interviews with program officials and school administrators, we found that the instrument was being used as a tool for helping teachers to improve their school climate and management skills. We discuss the importance of constructing instruments using a mixed-methods approach.  相似文献   

Teenage attitudes towards sexual diversity in Spain     

Lidón Moliner Miravet  Andrea Francisco Amat  Arecia Aguirre García-Carpintero 《Sex education》2018,18(6):689-704

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A critique of mutualism’s combination of the Aristotelian and Kantian traditions     

Francisco Javier Lopez Frías 《体育哲学杂志》2018,45(2):161-176

In this article, I will identify two key normative principles at the core of Robert L. Simon’s mutualist theory of sport, namely, the respect-for-the-opponent principle and the idea that sport is a practice aimed at pursuing excellence. The former is a Kantian principle grounded in human beings’ rationality, and the latter is an Aristotelian principle related to the development of excellences as a means to human flourishing. After having presented and analyzed both principles, I will critically evaluate Simon’s attempt to combine them within his mutualist approach. To conclude, I will highlight the challenges that mutualism should face to complete such a combination more successfully.

Abbreviation: Categorical imperative (CI)  相似文献   

Exploring the perspectives of physically active and inactive adolescents: how does physical education influence their lifestyles?     

João Martins  Adilson Marques  António Rodrigues  Hugo Sarmento  Marcos Onofre  Francisco Carreiro da Costa 《Sport, Education and Society》2018,23(5):505-519

Based on a socio-ecological framework for physical education (PE), this study explored and analysed the perspectives of physically active and inactive adolescent boys and girls with different socioeconomic status (SES), regarding the meanings that PE had on their physical activity (PA) lifestyles throughout childhood and adolescence. An interpretative and qualitative design was adopted and operationalised through an individual two-hours in-depth interview. Thematic analysis identified five main themes that distinguish active from inactive adolescents: ‘Early experiences of PE at primary school’; ‘PE experiences in middle and secondary school’; ‘Friendly, professional and pedagogue. That’s what I want from my PE teacher’; ‘Friends in PE and PA’; ‘Active lifestyles? Are schools and PE ready for making a difference?…’. Regardless of the lifestyle, girls revealed more PE negative experiences, related to uninteresting and competitive activities, groups’ constitution and logistic factors. SES played a major role on their PA and PE experiences, with low SES adolescents having limited opportunities inclusively within the primary school PE context. This study provides evidence for the importance of promoting positive PE and PA experiences in early years. Based on adolescents’ voices, several recommendations are discussed that can be considered for improving PE professionals’ effectiveness in promoting active lifestyles.  相似文献   

Football transfers and moral responsibility     

Francisco Javier López Frías 《Soccer & Society》2018,19(4):560-572

The main goal of this paper is to analyse the concept of social responsibility in sport management. By drawing on Hans Jonas, I shall analyse the concept of ‘corporate social responsibility’ in order to analyse several ambivalent cases within contemporary soccer such as the transfer of Gareth Bale to Real Madrid or the awarding of the 2022 World Cup to Qatar.  相似文献   

Aerobic training but no resistance training increases SIRT3 in skeletal muscle of sedentary obese male adolescents     

Katya Vargas-Ortiz  Victoriano Pérez-Vázquez  Arturo Figueroa  Francisco J. Díaz  Paulina G. Montaño-Ascencio 《European Journal of Sport Science》2018,18(2):226-234

In recent years, prevalence of obesity in children and adolescents has increased. A strategy for prevention and management of obesity is aerobic training (AT) due to its effectiveness to decrease fat mass. AT increases the content of SIRT3, a mitochondrial protein that increases the expression of PGC-1α and NFR1, thereby enhances mitochondrial function and metabolic health. Resistance training (RT) provides metabolic benefits but its effect on SIRT3 content is unknown. To compare the effect of AT and RT on SIRT3, PGC-1α and NRF-1 protein levels in skeletal muscle of sedentary obese adolescents. Twenty-seven sedentary obese male adolescents (age: 16.7?±?0.9 years; BMI: 33.7?±?4.3?kg/m²) completed a 1-month control period prior to randomization to one of two supervised exercise protocols: AT (3 days/week, 40 min/day, 70–80% peak heart rate) or RT (3 days/week, 11 exercises, 2 sets/exercise, 12 repetitions/set) for 12 weeks. Biopsies were obtained from the vastus lateralis muscle before and after 12 weeks to analyse SIRT3, PGC-1α and NRF-1 proteins content. Peak oxygen consumption (VO_2peak) and anthropometric variables were evaluated before and after training. AT increased SIRT3 content, which was associated with improvements in PGC-1α content and body fat percentage. RT did not affect SIRT3 or PGC-1α. VO_2peak increased only in AT. The increase in muscle mitochondrial SIRT3 was observed only following AT. In contrast, RT increased muscle mass without improving SIRT3 in obese male adolescents.  相似文献