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1.
Learn Instr ; 80: 101629, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35578734

RESUMEN

The outbreak of the COVID-19 pandemic has had a wide range of negative consequences for higher education students. We explored the generalizability of the control-value theory of achievement emotions for e-learning, focusing on their antecedents. We involved 17019 higher education students from 13 countries, who completed an online survey during the first wave of the pandemic. A structural equation model revealed that proximal antecedents (e-learning self-efficacy, computer self-efficacy) mediated the relation between environmental antecedents (cognitive and motivational quality of the task) and positive and negative achievement emotions, with some exceptions. The model was invariant across country, area of study, and gender. The rates of achievement emotions varied according to these same factors. Beyond their theoretical relevance, these findings could be the basis for policy recommendations to support stakeholders in coping with the challenges of e-learning and the current and future sequelae of the pandemic.

2.
PLoS One ; 16(10): e0258807, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34669757

RESUMEN

The outbreak of the COVID-19 pandemic has dramatically shaped higher education and seen the distinct rise of e-learning as a compulsory element of the modern educational landscape. Accordingly, this study highlights the factors which have influenced how students perceive their academic performance during this emergency changeover to e-learning. The empirical analysis is performed on a sample of 10,092 higher education students from 10 countries across 4 continents during the pandemic's first wave through an online survey. A structural equation model revealed the quality of e-learning was mainly derived from service quality, the teacher's active role in the process of online education, and the overall system quality, while the students' digital competencies and online interactions with their colleagues and teachers were considered to be slightly less important factors. The impact of e-learning quality on the students' performance was strongly mediated by their satisfaction with e-learning. In general, the model gave quite consistent results across countries, gender, study fields, and levels of study. The findings provide a basis for policy recommendations to support decision-makers incorporate e-learning issues in the current and any new similar circumstances.


Asunto(s)
Rendimiento Académico , COVID-19/epidemiología , Educación a Distancia , Pandemias , SARS-CoV-2 , Adolescente , Adulto , Femenino , Humanos , Masculino
3.
Sci Rep ; 9(1): 18151, 2019 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-31776442

RESUMEN

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

4.
Sci Rep ; 9(1): 7434, 2019 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-31092870

RESUMEN

This paper presents a digital elevation model (DEM) of the dunes found in the Lençóis Maranhenses National Park, an environmental protection area located in the Maranhão state (Brazil). The DEM supports the modeling studies of sand-dune evolution using multi-temporal satellite images and ground truth data, obtained through the post-processed kinematic Global Navigation Satellite System (GNSS) positioning. The study area is located at the border of three major neotropical ecosystems: the Amazonia, Caatinga, and Brazilian savanna. It is located in the northeastern state of Maranhão and encompasses the largest dune fields in the country. Wide shrubby areas (restingas, in Portuguese), lakes, mangroves, and a multitude off reshwater lagoons compose the park's natural environments. The objective of the present study is to create an DEM that can evidence the complex dynamics of dune formation in the study area with use of GNSS. Geodetic techniques and precision mapping were employed to monitor the short-term coastal dynamics. The use of GNSS receivers is justified by the difficulty of mapping the dune's features using conventional methods such as theodolite, level, and total station systems, due to their high cost, time restriction sand low data precision. Surface surveys were carried out annually between December 2015 and January 2017 to create a DEM. The study results reveal that the area has a negative volumetric balance of erosion and a preferential direction of sediment transport by wind, which may justify the pattern of advancement and retraction observed in the dunes of the studied area.

7.
Neotrop. entomol ; 32(4): 699-706, Oct.-Dec. 2003. tab
Artículo en Portugués | LILACS | ID: lil-513671

RESUMEN

Avaliou-se a ação fisiológica de triclorfom, triflumurom, endosulfam, fempropatrina, clorpirifós, tebufenozide e esfenvalerato em larvas de 2° ínstar de Chrysoperla externa (Hagen) e seus efeitos subseqüentes sobre o 3° ínstar, pupas e adultos. Os experimentos foram realizados em casa de vegetação, avaliando-se o efeito de contato dos inseticidas em larvas de 2° ínstar, mantidas em algodoeiros pulverizados, e o efeito sobre larvas nesse estádio que se alimentaram de ovos de Anagasta kuehniella (Zeller) tratados com inseticidas. Foi avaliada a sobrevivência dos indivíduos no 2° e 3° ínstares e na fase de pupa. Na fase adulta, verificou-se a produção diária e total de ovos durante 30 dias e a viabilidade e fertilidade dos ovos. Endosulfam, tebufenozide e esfenvalerato foram seletivos às larvas de 2° ínstar tanto por contato como pela sucção do conteúdo de ovos tratados. Para larvas de 3° ínstar, esses inseticidas não foram prejudiciais, assim como o triflumuron. A sobrevivência de pupas oriundas de larvas de 2° ínstar tratadas com fempropatrina e tebufenozide não foi afetada. Triclorfom, fempropatrina e tebufenozide não provocaram redução no número total de ovos produzidos pelas fêmeas provenientes de larvas alimentadas com ovos tratados. Esfenvalerato, por contato, não reduziu significativamente a produção total de ovos. Por se apresentar seletivo às larvas de 2° ínstar de C. externa, tebufenozide apresenta características favoráveis para uso em associação com liberações inundativas do predador para o controle de pragas na cultura do algodoeiro, embora tenha afetado sua capacidade reprodutiva.


The physiological action of the insecticides trichlorfon, triflumuron, endosulfan, fenpropathrin, chlorpiryfos, tebufenozide and esfenvalerate to 2nd-instar larvae of Chrysoperla externa (Hagen) and subsequent effects on 3rd-instar larvae, pupae and adults were evaluated. The bioassays were carried out under greenhouse conditions. The effect on larvae fed on eggs of Anagasta kuehniella (Zeller) treated with the insecticides was evaluated, as well as the contact effect on 2nd-instar larvae kept on sprayed cotton plants. The survival percentage of individuals in the second- and 3rd-instar and in the pupae stage was determined. For adults, the daily and total production of eggs during 30 days, the viability and the fertility of eggs were evaluated. Endosulfan, tebufenozide and esfenvalerate were selective to 2nd-instar larvae by contact on sprayed plants as well as by suction of treated eggs. For 3rd-instar larvae, neither endosulfan, tebufenozide, esfenvalerate nor triflumuron were harmful. The survival of pupae from treated 2nd-instar larvae with fenpropathrin and tebufenozide was not affected. Trichlorfon, fenpropathrin and tebufenozide caused no reduction in the total number of eggs produced by females derived from 2nd-instar larvae fed with treated eggs of A. kuehniella. Females originated from larvae that kept contact with sprayed cotton plants with esfenvalerate, had no significant reduction in the total egg production. Although tebufenozide affected the reproductive traits of C. externa, it can be recommended for controlling the pests on cotton crop in association with inundative releases of this predator.

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