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The detection of methane on Mars has been interpreted as indicating that geochemical or biotic activities could persist on Mars today1. A number of different measurements of methane show evidence of transient, locally elevated methane concentrations and seasonal variations in background methane concentrations2-5. These measurements, however, are difficult to reconcile with our current understanding of the chemistry and physics of the Martian atmosphere6,7, which-given methane's lifetime of several centuries-predicts an even, well mixed distribution of methane1,6,8. Here we report highly sensitive measurements of the atmosphere of Mars in an attempt to detect methane, using the ACS and NOMAD instruments onboard the ESA-Roscosmos ExoMars Trace Gas Orbiter from April to August 2018. We did not detect any methane over a range of latitudes in both hemispheres, obtaining an upper limit for methane of about 0.05 parts per billion by volume, which is 10 to 100 times lower than previously reported positive detections2,4. We suggest that reconciliation between the present findings and the background methane concentrations found in the Gale crater4 would require an unknown process that can rapidly remove or sequester methane from the lower atmosphere before it spreads globally.
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The surname of author Cathy Quantin-Nataf was misspelled 'Quantin-Nata', authors Ehouarn Millour and Roland Young were missing from the ACS and NOMAD Science Teams list, and minor changes have been made to the author and affiliation lists; see accompanying Amendment. These errors have been corrected online.
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Global dust storms on Mars are rare1,2 but can affect the Martian atmosphere for several months. They can cause changes in atmospheric dynamics and inflation of the atmosphere3, primarily owing to solar heating of the dust3. In turn, changes in atmospheric dynamics can affect the distribution of atmospheric water vapour, with potential implications for the atmospheric photochemistry and climate on Mars4. Recent observations of the water vapour abundance in the Martian atmosphere during dust storm conditions revealed a high-altitude increase in atmospheric water vapour that was more pronounced at high northern latitudes5,6, as well as a decrease in the water column at low latitudes7,8. Here we present concurrent, high-resolution measurements of dust, water and semiheavy water (HDO) at the onset of a global dust storm, obtained by the NOMAD and ACS instruments onboard the ExoMars Trace Gas Orbiter. We report the vertical distribution of the HDO/H2O ratio (D/H) from the planetary boundary layer up to an altitude of 80 kilometres. Our findings suggest that before the onset of the dust storm, HDO abundances were reduced to levels below detectability at altitudes above 40 kilometres. This decrease in HDO coincided with the presence of water-ice clouds. During the storm, an increase in the abundance of H2O and HDO was observed at altitudes between 40 and 80 kilometres. We propose that these increased abundances may be the result of warmer temperatures during the dust storm causing stronger atmospheric circulation and preventing ice cloud formation, which may confine water vapour to lower altitudes through gravitational fall and subsequent sublimation of ice crystals3. The observed changes in H2O and HDO abundance occurred within a few days during the development of the dust storm, suggesting a fast impact of dust storms on the Martian atmosphere.
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The surname of author Cathy Quantin-Nataf was misspelled 'Quantin-Nata' , authors Ehouarn Millour and Roland Young were missing from the ACS Science Team list, and minor changes have been made to the author and affiliation lists; see accompanying Amendment. These errors have been corrected online.
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Effective environmental management higher education programs are essential for achieving the Sustainable Development Goals (SDGs). Yet SDG complexity means many educators focus on environment and avoid critical but challenging social, economic and governance aspects. This undermines the calls for comprehensive environmental management education that effectively integrates all key sustainability dimensions. Various sustainability models, mostly founded on the pillars of sustainability, have consequently evolved. They are generally conceptual and/or involve subjective categorization of the SDGs, which has led to demands for more empirically based models. This study has consequently used a mixed-method approach to model Australian university students' SDG perceptions. The qualitative research identified three items (on average) for each SDG, and a quantitative survey then measured their perceived importance. Factor analysis generated a robust six-dimensional sustainable development model comprised of 37 SDG items, which validates environment and governance aspects of some traditional pillar-based sustainability models. It has also uncovered new social and economic dimensions: social harmony and equality; sustainable consumption and socioeconomic behaviors; sustainable production, industry and infrastructure; and acute poverty reduction. These findings can help educators, organizations and citizens to categorize and integrate SDGs via better understanding of their key dimensions and impacts.
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Conservação dos Recursos Naturais , Desenvolvimento Sustentável , Humanos , Austrália , PobrezaRESUMO
Beginning in the late 1970s, 10- to 15-year cyclical oscillations in salinity were observed at lower Colorado River monitoring sites, moving upstream from the international border with Mexico, above Imperial Dam, below Hoover Dam, and at Lees Ferry. The cause of these cyclical trends in salinity was unknown. These salinity cycles complicate the U.S. Bureau of Reclamation's (Reclamation) responsibility for managing salinity in the river for delivery of water to Mexico to meet treaty obligations. This study develops a conceptual model of the salinity cycles from time-series water quality, streamflow, and precipitation data in both the lower and upper Colorado River Basins in order to provide Reclamation the ability to understand, anticipate, and manage future salinity cycles in the lower river. Compared with the Lees Ferry record, both maximum and minimum salinity levels increase downstream by about 25% at Hoover Dam, by about 49% at Imperial Dam, and by about 69% at the northern international boundary with Mexico. In the upper basin, cyclical salinity trends are evident at the outflow of three major tributaries, where salinity is also noted to be inversely related to streamflow. Time series trends in precipitation within the catchments of the three upper basin tributaries indicate cyclical periods with above normal precipitation and periods with below normal precipitation. Periods of greater than normal precipitation in the contributing areas correspond with declines in salinity at the catchment monitoring sites and periods of less than normal precipitation correspond with rising salinity at the sites. Based on the conceptual model developed in this investigation, a multiple linear regression model was developed using a stepwise variable selection procedure to simulate salinity in Lake Powell inflow. Important variables in the explanation of salinity entering Lake Powell include flow from the three upper basin tributaries, seasonality, and mean precipitation in the upper basin, among others. The root mean square error of prediction for the MLR model was 31.48â¯mg/L (5.7%).
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Monitoramento Ambiental , Salinidade , Colorado , México , RiosRESUMO
The NOMAD instrument has been designed to best fulfil the science objectives of the ExoMars Trace Gas Orbiter mission that will be launched in 2016. The instrument is a combination of three channels that cover the UV, visible and IR spectral ranges and can perform solar occultation, nadir and limb observations. In this series of two papers, we present the optical models representing the three channels of the instrument and use them to determine signal to noise levels for different observation modes and Martian conditions. In this first part, we focus on the UVIS channel, which will sound the Martian atmosphere using nadir and solar occultation viewing modes, covering the 200-650nm spectral range. High SNR levels (>1000) can easily be reached for wavelengths higher than 300nm both in solar occultation and nadir modes when considering binning. Below 300nm SNR are lower primarily because of the lower signal and the impact of atmospheric absorption.
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Worldwide, information technology now plays a substantial role in the daily life of most people, whether in the developed world or in developing countries, such as Indonesia. In this fourth most populated country in the world, information technology is widely used for everyday communications and entertainment purposes, as well as for supporting education. Using a survey of 496 students enrolled in a university in Jakarta, this paper reports on a study aimed at assessing the experiences of young Indonesian students undertaking online learning and the potential of this platform for English learning. The findings show that online activities, skills, and perceived usefulness were positively correlated with positive experiences of learning English online. In particular, the perceived usefulness of the Internet and the ability to use different functions of digital devices and applications had a stronger correlation with increased benefits of online English learning. The study generates implications for Indonesian education suggesting a review of the roles of English instructors in promoting English learning through technology, improvement in English instructors' skills in utilizing technology in their teaching, and support of relevant stakeholders as well as the preparation of English teacher preparation programme to support pre-service teachers for teaching with technology.
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Detecção Precoce de Câncer/métodos , Serviço Hospitalar de Emergência , Infecções por Papillomavirus/prevenção & controle , Vacinas contra Papillomavirus/uso terapêutico , Cooperação do Paciente , Neoplasias do Colo do Útero/diagnóstico , Adolescente , Adulto , Feminino , Hospitais Urbanos , Humanos , Teste de Papanicolaou , Projetos Piloto , Estudos Prospectivos , Neoplasias do Colo do Útero/prevenção & controle , Esfregaço Vaginal , Adulto JovemRESUMO
[This corrects the article DOI: 10.1186/s41039-021-00166-8.].
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Due to COVID-19, universities with limited expertise with the digital environment had to rapidly transition to online teaching and assessment. This transition did not create a new problem but has offered more opportunities for contract cheating and diversified the types of such services. While universities and lecturers were adjusting to the new teaching styles and developing new assessment methods, opportunistic contract cheating providers have been offering $50 COVID-19 discounts and students securing the services of commercial online tutors to take their online exams or to take advantage of real-time assistance from 'pros' while sitting examinations. The article contributes to the discourse on contract cheating by reporting on an investigation of the scope and scale of the growing problems related to academic integrity exacerbated by an urgent transition to online assessments during the COVID-19 pandemic. The dark reality is the illegal services are developing at a faster pace than the systems required to curb them, as demonstrated by the results. The all-penetrating issues indicate systemic failures on a global scale that cannot be addressed by an individual academic or university acting alone. Multi-level solutions including academics, universities and the global community are essential. Future research must focus on developing a model of collaboration to address this problem on several levels, taking into account (1) individual academics, (2) universities, (3) countries and (4) international communities.
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The goal of this study was to assess institutional climate and providers' readiness to adopt pediatric pathways for asthma treatment and management. Twelve focus groups were held with 24 physicians/physicians' assistants, 20 nurses, and 17 emergency medical technicians from emergency departments in 4 general hospitals from July to October 2002. Positive experience with previous pathways, open communication and buy-in from clinicians and administrators, comprehensive training on pathways, and adapting standards to fit specific emergency department environments were identified as necessary elements for pathway adoption. Providers were optimistic about successfully implementing an asthma pathway (95%) and supportive of pathway implementation (87%).
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Asma/terapia , Atitude do Pessoal de Saúde , Auxiliares de Emergência , Serviço Hospitalar de Emergência , Pediatria , Recursos Humanos em Hospital , Adolescente , Adulto , Asma/epidemiologia , Criança , Pré-Escolar , Serviços Médicos de Emergência , Grupos Focais , Humanos , Pessoa de Meia-IdadeRESUMO
In providing a meta-analysis of a series of workshop papers and questions arising on the emergent field of learning analytics, this paper contributes to the ongoing formation of a shared research agenda. The first ICCE Learning Analytics workshop in 2014 demonstrated the effectiveness of a focused questioning session for collecting relevant data beyond the content of the papers themselves. In December 2014, approximately 40 participants attended the workshop held in Nara, Japan, and contributed to the collection of open research questions. Six papers were presented covering topics including scope; interoperability standards; privacy and control of individual data, extracting data from learning content and processes; and the development of conceptual frameworks. These papers established a base from which the group generated a set of questions that invite further investigation. Utilising the first stage of the Question Formulation Technique, a pedagogical approach designed to stimulate student inquiry, a prominent finding from the workshop that questions emerging from focused inquiry provide a useful set of data in their own right. With an explicit workshop focus on learning analytics interoperability, this paper reports on the emergent issues identified in the workshop and the kinds of questions associated with each issue in the context of current research in the field of learning analytics. The study considers the complexity arising from the fact that data associated with learning is itself becoming a digital learning resource while also enabling analysis of learner behaviours and systems usage.
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OBJECTIVE: To determine the incidence and frequency of follow-up instructions for incidental findings on computed tomography (CT) scanning of the abdomen and pelvis in trauma patients. METHODS: We performed a retrospective chart review of all adult patients triaged to the trauma service at a Level I trauma center between July 1, 2003 and June 30, 2004. Included patients were 16 years of age and older who underwent abdomen and pelvic CT scans as part of their primary evaluation. We excluded patients under the age of 16 years, patients unable to complete radiographic studies due to deterioration in condition, patients with missing CT scan reports, and transferred patients who had CT scans done at outside facilities. RESULTS: A total of 1,633 patients presented to the trauma service during the study period; 922 patients met inclusion criteria. Of these, 392 had incidental findings noted on the formal radiology report. Twenty patients with incidental findings either received additional workup during their hospital admission for their trauma injuries or were notified of the findings on discharge. Nine died prior to discharge. One hundred twenty-two patients with incidental findings had those findings noted in the history and physical or discharge summary with no documentation of follow-up. There was no documentation of any incidental findings in the electronic record for the majority of patients (242) with incidental findings. CONCLUSION: The majority of incidental findings discovered on abdomen and pelvic CT scanning of trauma patients are not documented; therefore, many patients may not receive the appropriate recommended follow up.