345 research outputs found
No Social Distancing: Challenges and Collaboration in the Use of Computer-Mediated Learning (CML) Experienced by Selected Students in the Master of Education in English as Second Language Course during the Time of the Coronavirus
The COVID-19 pandemic forced higher learning institutions to shift to the remote mode paving the way for computer-mediated learning (CML), a new yet familiar method of engagement between the teacher and the students. The main purpose of this study is to discuss the challenges experienced and the manner of peer collaboration as students maximized the teaching and learning process in such a setup. The study is descriptive-qualitative by design. It involves a thematic analysis of the corpus collected from selected participants who shared their experiences on CML. The respondents of this study were enrolled in the Master of Education in English as a Second Language (M.Ed.-ESL) course. Before distributing the questions, the researcher explained the features of CML. She, then, proceeded to secure their consent. After which, she coded and extracted the sub-themes and themes. These were collated, categorized in a matrix, and validated. Verbatim statements to support the results were provided. Results showed the themes on challenges are internet connectivity, online tools and gadgets, motivation, emotional and mental health, limited interaction, environmental distractions, physical wellness, time management, and access to learning resources. Themes on collaboration showed that the participants work and interact through online applications and tools, adjust to peersâ schedules, and provide mutual peer support. The results also showed challenges even while they were collaborating such as internet connectivity, unfamiliar forms of class participation, untimely feedback, among others. This study furnished valuable insights in overcoming the difficulties that students encounter in CML especially on the affective aspect of the CML. This should improve collaboration between the mentors and the students, and among the students themselves, which could be beneficial in adapting to this new setup. An audit of CML tools describing how to navigate CML could assist the teachers and students to overcome the challenges, especially on collaboration, and banish a sense of isolation that is posed by this mode of learning
Beyond the Classroom: Using Google Sites as a Supplementary Material to Improve the Learnersâ English Academic Performance
The present study investigated the common challenges of learners in the new mode of learning and their frequency, if there would be a significant difference in the performance of the participants after using Google Sites, the acceptability of the Google Sites in terms of its content quality, instructional quality, and technical quality, and the experience of the respondents in using Beyond the Classroom as supplementary material for the Third Quarter. This action research used the survey questionnaires, evaluation tool, pre-tests, and posttest as instruments in answering the research questions. Respondents were 15 Grade 8 High School learners who have internet access. Results indicated always and sometimes characterized their experience on challenges such as understanding the lessons after reading the discussion found in the modules and that there is a significant difference between the pre-test and post-test scores for lessons that are easy for them to understand and learn alone. Results also revealed that Beyond the Classroom is very acceptable in terms of its content, instructional, and technical quality, and respondents found it helpful in understanding their lessons. Finally, this study showed that learners struggle to cope with the changes in the new normal, and online supplementary material helps them understand their lessons and activities for the Third Quarter of the academic year 2021-2022
Probing of local ferroelectricity in BiFeO3 thin films and (BiFeO3)m(SrTiO3)m superlattices
Ferroelectric BiFeO3 thin films and artificial superlattices of
(BiFeO3)m(SrTiO3)m (m~ 1 to 10 unit cells) were fabricated on (001)-oriented
SrTiO3 substrates by pulsed laser ablation. The variation of leakage current
and macroscopic polarization with periodicity was studied. Piezo force
microscopy studies revealed the presence of large ferroelectric domains in the
case of BiFeO3 thin films while a size reduction in ferroelectric domains was
observed in the case of superlattice structures. The results show that the
modification of ferroelectric domains through superlattice, could provide an
additional control on engineering the domain wall mediated functional
properties.Comment: 14 pages, To be published in J. Mag. Mag Mater. proceedings of EMRS
200
The ESO supernovae type Ia progenitor survey (SPY) : The radial velocities of 644 DA white dwarfs
Accepted for publication in A&A. 59 pages.Close double degenerate binaries are one of the favoured progenitor channels for type Ia supernovae, but it is unclear how many suitable systems there are in the Galaxy. We report results of a large radial velocity survey for double degenerate (DD) binaries using the UVES spectrograph at the ESO VLT (ESO SN Ia Progenitor surveY - SPY). Exposures taken at different epochs are checked for radial velocity shifts indicating close binary systems. We observed 689 targets classified as DA (displaying hydrogen-rich atmospheres), of which 46 turned out to possess a cool companion. We measured radial velocities (RV) of the remaining 643 DA white dwarfs. We managed to secure observations at two or more epochs for 625 targets, supplemented by eleven objects meeting our selection criteria from literature. The data reduction and analysis methods applied to the survey data are described in detail. The sample contains 39 double degenerate binaries, only four of which were previously known. 20 are double-lined systems, in which features from both components are visible, the other 19 are single-lined binaries. We provide absolute RVs transformed to the heliocentric system suitable for kinematic studies. Our sample is large enough to sub-divide by mass: 16 out of 44 low mass targets (0.45 Msun are double. Although the detected fraction amongst the low mass objects (36.4 +/- 7.3%) is significantly higher than for the higher-mass, carbon/oxygen-core dominated part of the sample (3.9 +/- 0.8%), it is lower than the detection efficiency based upon companion star masses >= 0.05 Msun. This suggests either companion stars of mass <0.05 Msun, or that some of the low mass white dwarfs are single.Peer reviewe
Occupational exposure and markers of genetic damage, systemic inflammation and lung function: a Danish cross-sectional study among air force personnel
Air force ground crew personnel are potentially exposed to fuels and lubricants, as raw materials, vapours and combustion exhaust emissions, during operation and maintenance of aircrafts. This study investigated exposure levels and biomarkers of effects for employees at a Danish air force military base. We enrolled self-reported healthy and non-smoking employees (n = 79) and grouped them by exposure based on job function, considered to be potentially exposed (aircraft engineers, crew chiefs, fuel operators and munition specialists) or as reference group with minimal occupational exposure (avionics and office workers). We measured exposure levels to polycyclic aromatic hydrocarbons (PAHs) and organophosphate esters (OPEs) by silicone bands and skin wipes (PAHs only) as well as urinary excretion of PAH metabolites (OH-PAHs). Additionally, we assessed exposure levels of ultrafine particles (UFPs) in the breathing zone for specific job functions. As biomarkers of effect, we assessed lung function, plasma levels of acute phase inflammatory markers, and genetic damage levels in peripheral blood cells. Exposure levels of total PAHs, OPEs and OH-PAHs did not differ between exposure groups or job functions, with low correlations between PAHs in different matrices. Among the measured job functions, the UFP levels were higher for the crew chiefs. The exposure level of the PAH fluorene was significantly higher for the exposed group than the reference group (15.9 +/- 23.7 ng/g per 24 h vs 5.28 +/- 7.87 ng/g per 24 h, p = 0.007), as was the OPE triphenyl phosphate (305 +/- 606 vs 19.7 +/- 33.8 ng/g per 24 h, p = 0.011). The OPE tris(1, 3-dichlor-2-propyl)phosphate had a higher mean in the exposed group (60.7 +/- 135 ng/g per 24 h) compared to the reference group (8.89 +/- 15.7 ng/g per 24 h) but did not reach significance. No evidence of effects for biomarkers of systemic inflammation, genetic damage or lung function was found. Overall, our biomonitoring study show limited evidence of occupational exposure of air force ground crew personnel to UFPs, PAHs and OPEs. Furthermore, the OH-PAHs and the assessed biomarkers of early biological effects did not differ between exposed and reference groups
Annual Research Review: Prevention of psychosis in adolescents â systematic review and metaâanalysis of advances in detection, prognosis and intervention
Background The clinical high-risk state for psychosis (CHR-P) paradigm has facilitated the implementation of psychosis prevention into clinical practice; however, advancements in adolescent CHR-P populations are less established. Methods We performed a PRISMA/MOOSE-compliant systematic review of the Web of Science database, from inception until 7 October 2019, to identify original studies conducted in CHR-P children and adolescents (mean age = 36 months.Interventions: There was not enough evidence to recommend one specific treatment (including cognitive behavioural therapy) over the others (including control conditions) to prevent the transition to psychosis in this population. Randomised controlled trials suggested that family interventions, cognitive remediation and fish oil supplementation may improve cognition, symptoms and functioning. At baseline, 30% of CHR-P adolescents were prescribed antipsychotics and 60% received psychotherapy. Conclusions It is possible to detect and formulate a group-level prognosis in adolescents at risk for psychosis. Future interventional research is required.G.S.d.P. and J.V.S. are supported by the Alicia Koplowitz Foundation. The study has been supported by the Spanish Ministry of Science, Innovation, and Universities, Instituto de Salud Carlos III, European Regional Development Fund 'A way of making Europe,' Centro de Investigacion Biomedica en Red Salud Mental, Madrid Regional Government; and Fundacion Mutua Madrilena.
A.C. has received personal fees from Janssen and grant support from the Instituto de Salud Carlos III, Spanish Ministry of Economy and Competitiveness. C.A. has been a consultant to or has received honoraria or grants from Acadia, Angelini, Gedeon Richter, Janssen Cilag, Lundbeck, Otsuka, Roche, Sage, Servier, Shire, Schering Plough, Sumitomo Dainippon Pharma, Sunovion and Takeda. C.M. has acted as consultant or participated in DMC for Janssen, Servier, Lundbeck, Nuvelution, Angelini and Otsuka and has received grant support from European Union Funds and Instituto de Salud Carlos III, Spanish Ministry of Economy and Competitiviness. C.U.C. has been a consultant and/or adviser to or has received honoraria from: Alkermes, Allergan, Angelini, Boehringer-Ingelheim, Gedeon Richter, Gerson Lehrman Group, Indivior, IntraCellular Therapies, Janssen/J&J, LB Pharma, Lundbeck, MedAvante-ProPhase, Medscape, Merck, Neurocrine, Noven, Otsuka, Pfizer, Recordati, Rovi, Servier, Sumitomo Dainippon, Sunovion, Supernus, Takeda and Teva. He has provided expert testimony for Bristol-Myers Squibb, Janssen and Otsuka. He served on a Data Safety Monitoring Board for Boehringer-Ingelheim, Lundbeck, Rovi, Supernus, and Teva. He received royalties from UpToDate and grant support from Janssen and Takeda. He is also a shareholder of LB Pharma. P.F-P. has been a consultant to and received research funds from Lundbeck and received honoraria from Menarini and Angelin
Pulmonary toxicity of synthetic amorphous silicaâeffects of porosity and copper oxide doping
Materials can be modified for improved functionality. Our aim was to test whether pulmonary toxicity of silica nanomaterials is increased by the introduction of: a) porosity; and b) surface doping with CuO; and whether c) these modifications act synergistically. Mice were exposed by intratracheal instillation and for some doses also oropharyngeal aspiration to: 1) solid silica 100 nm; 2) porous silica 100 nm; 3) porous silica 100 nm with CuO doping; 4) solid silica 300 nm; 5) porous silica 300 nm; 6) solid silica 300 nm with CuO doping; 7) porous silica 300 nm with CuO doping; 8) CuO nanoparticles 9.8 nm; or 9) carbon black Printex 90 as benchmark. Based on a pilot study, dose levels were between 0.5 and 162 ”g/mouse (0.2 and 8.1 mg/kg bw). Endpoints included pulmonary inflammation (neutrophil numbers in bronchoalveolar fluid), acute phase response, histopathology, and genotoxicity assessed by the comet assay, micronucleus test, and the gamma-H2AX assay. The porous silica materials induced greater pulmonary inflammation than their solid counterparts. A similar pattern was seen for acute phase response induction and histologic changes. This could be explained by a higher specific surface area per mass unit for the most toxic particles. CuO doping further increased the acute phase response normalized according to the deposited surface area. We identified no consistent evidence of synergism between surface area and CuO doping. In conclusion, porosity and CuO doping each increased the toxicity of silica nanomaterials and there was no indication of synergy when the modifications co-occurred
Drivers of atmospheric deposition of polycyclic aromatic hydrocarbons at European high-altitude sites
Polycyclic aromatic hydrocarbons (PAHs) were analysed in bulk atmospheric deposition samples collected at four European high-mountain areas, Gossenköllesee (Tyrolean Alps), Redon (Central Pyrenees), Skalnate Pleso (High Tatra Mountains), and Lochnagar (Grampian Mountains) between 2004 and 2006. Sample collection was performed monthly in the first three sites and biweekly in Lochnagar. The number of sites, period of study and sampling frequency provide the most comprehensive description of PAH fallout in high mountain areas addressed so far.
The average PAH deposition fluxes in Gossenköllesee, Redon and Lochnagar ranged between 0.8 and 2.1”gmâ2monthâ1, and in Skalnate Pleso it was 9.7”gmâ2monthâ1, showing the influence of substantial inputs from regional emission sources. The deposited distributions of PAHs were dominated by parent phenanthrene, fluoranthene and pyrene, representing 32%â60% of the total. The proportion of phenanthrene, the most abundant compound, was higher at the sites of lower temperature, Gossenköllesee and Skalnate Pleso, showing higher transfer from gas phase to particles of the more volatile PAHs. The sites with lower insolation, e.g. those located at lower altitude, were those with a higher proportion of photooxidable compounds such as benz[a]anthracene.
According to the data analysed, precipitation is the main driver of PAH fallout. However, when rain and snow deposition were low, particle settling also constituted an efficient driver for PAH deposition. Redon and Lochnagar were the two sites receiving the highest amounts of rain and snow and the fallout of PAH fluxes was related to this precipitation. No significant association was observed between long-range backward air trajectories and PAH deposition in Lochnagar, but in Redon PAH fallout at higher precipitation was essentially related to air masses originating from the North Atlantic, which were dominant between November and May (cold season). In these cases, particle-normalised PAH fallout was also associated with higher precipitation as these air masses were concurrent with lower temperatures, which enhanced gas to particle partitioning transfer. In the warm season (JuneâOctober), most of the air masses arriving at Redon originated from the south and particle deposition was enhanced as consequence of Saharan inputs. In these cases, particle settling was also a driver of PAH deposition despite the low overall PAH content of the Saharan particles.
In Gossenköllesee, the site receiving lowest precipitation, PAH fallout was also related to particle deposition. The particle-normalised PAH fluxes were significantly negatively correlated to temperature, e.g. for air masses originating from central and eastern Europe, showing a dominant transfer from gas phase to particles at lower temperatures, which enhanced PAH fallout, mainly of the most volatile hydrocarbons.
Comparison of PAH atmospheric deposition and lacustrine sedimentary fluxes showed much higher values in the latter case of 24â100”gmâ2yrâ1 vs. 120â3000”gmâ2yrâ1. A strong significant correlation was observed between these two fluxes, which is consistent with a dominant origin related to atmospheric deposition at each site
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