Exclusion of Stellar Companions to Exoplanet Host Stars

Given the frequency of stellar multiplicity in the solar neighborhood, it is important to study the impacts this can have on exoplanet properties and orbital dynamics. There have been numerous imaging survey projects established to detect possible low-mass stellar companions to exoplanet host stars. Here we provide the results from a systematic speckle imaging survey of known exoplanet host stars. In total, 71 stars were observed at 692~nm and 880~nm bands using the Differential Speckle Survey Instrument (DSSI) at the Gemini-North Observatory. Our results show that all but 2 of the stars included in this sample have no evidence of stellar companions with luminosities down to the detection and projected separation limits of our instrumentation. The mass-luminosity relationship is used to estimate the maximum mass a stellar companion can have without being detected. These results are used to discuss the potential for further radial velocity follow-up and interpretation of companion signals.Comment: 11 pages, 4 figures, 3 tables, accepted for publication in A

SCIAMACHY formaldehyde observations: constraint for isoprene emission estimates over Europe?

Formaldehyde (HCHO) is an important intermediate compound in the degradation of volatile organic compounds (VOCs) in the troposphere. Sources of HCHO are largely dominated by its secondary production from VOC oxidation, methane and isoprene being the main precursors in unpolluted areas. As a result of the moderate lifetime of HCHO, its spatial distribution is determined by reactive hydrocarbon emissions. We focus here on Europe and investigate the influence of the different emissions on HCHO tropospheric columns with the CHIMERE chemical transport model in order to interpret the comparisons between SCIAMACHY and simulated HCHO columns. Europe was never specifically studied before for these purposes using satellite observations. The bias between measurements and model is less than 20% on average. The differences are discussed according to the errors on the model and the observations and remaining discrepancies are attributed to a misrepresentation of biogenic emissions. This study requires the characterisation of: (1) the model errors and performances concerning formaldehyde. The errors on the HCHO columns, mainly related to chemistry and mixed emission types, are evaluated to 2×10<sup>15</sup> molecule/cm<sup>2</sup> and the model performances evaluated using surface measurements are satisfactory (~13%); (2) the observation errors that define the needs in spatial and temporal averaging for meaningful comparisons. Using SCIAMACHY observations as constraint for biogenic isoprene emissions in an inverse modelling scheme reduces their uncertainties by about a factor of two in region of intense emissions. The retrieved correction factors for the isoprene emissions range from a factor of 0.15 (North Africa) to a factor of 2 (Poland, the United Kingdom) depending on the regions

Sociology and postcolonialism: another 'missing' revolution?

Sociology is usually represented as having emerged alongside European modernity. The latter is frequently understood as sociology's special object with sociology itself a distinctively modern form of explanation. The period of sociology's disciplinary formation was also the heyday of European colonialism, yet the colonial relationship did not figure in the development of sociological understandings. While the recent emergence of postcolonialism appears to have initiated a reconsideration of understandings of modernity, with the development of theories of multiple modernities, I suggest that this engagement is more an attempt at recuperating the transformative aspect of postcolonialism than engaging with its critiques. In setting out the challenge of postcolonialism to dominant sociological accounts, I also address `missing feminist/queer revolutions', suggesting that by engaging with postcolonialism there is the potential to transform sociological understandings by opening up a dialogue beyond the simple pluralism of identity claims

Webteaching: sequencing of subject matter in relation to prior knowledge of pupils

Two experiments are discussed in which the sequencing procedure of webteaching is compared with a linear sequence for the presentation of text material.\ud \ud In the first experiment variations in the level of prior knowledge of pupils were studied for their influence on the sequencing mode of text presentation. Prior knowledge greatly reduced the effect of the size of sequencing procedures.\ud \ud In the second experiment pupils with a low level of prior knowledge studied a text, following either a websequence or a linear sequence. Webteaching was superior to linear teaching on a number of dependent variables. It is concluded that webteaching is an effective sequencing procedure in those cases where substantial new learning is required

Ground-based measurements of tropospheric and stratospheric bromine monoxide above Nairobi (1° S, 36° E)

International audienceGround based observations of stratospheric and tropospheric bromine monoxide, BrO, from a multi axial differential optical absorption spectrometer, MAXDOAS, located at the UNEP/UNON site in Nairobi (1° S, 36° E) are presented for the year 2003. Differences in BrO slant column densities at 90° and 80° solar zenith angle retrieved from the zenith-sky measurements are used to study stratospheric BrO. They show only small variations with season, as expected for the small seasonality in stratospheric Bry and NO2 in this region. A pronounced diurnal variation can be observed, the average value for the morning being 1.3×1014 molecules/cm2 and for the evening 1.5×1014 molecules/cm2. The measurements are compared with simulations from a one-dimensional photochemical stacked box model which is coupled with a radiative transfer model to allow direct comparisons between the observations and the model calculations. In general the model reproduces the measurements very well. The differences in the absolute values are 15% for the evening and 20% for the morning which is within the limits of the combined uncertainties. Both seasonality and diurnal variation are well reproduced by the model. A sensitivity study shows that inclusion of the reaction BrONO2 + O(3P) significantly improves the agreement between model calculations and measurements, indicating an important role of this reaction in the stratosphere near to the equator. Tropospheric BrO columns and profile information is derived from the combined results obtained in the different viewing directions for the average over several clear days. The resulting tropospheric BrO columns are in the range of 4?7.5×1012 molecules/cm2 which is significant but lower than in previous studies at mid and high latitudes. The vertical distribution of the tropospheric BrO peaks at about 3 km indicating the absence of local sources at this high altitude site

The Cabauw Intercomparison Campaign for Nitrogen Dioxide Measuring Instruments (CINDI): Design, Execution, and Early Results

From June to July 2009 more than thirty different in-situ and remote sensing instruments from all over the world participated in the Cabauw Intercomparison campaign for Nitrogen Dioxide measuring Instruments (CINDI). The campaign took place at KNMI's Cabauw Experimental Site for Atmospheric Research (CESAR) in the Netherlands. Its main objectives were to determine the accuracy of state-ofthe- art ground-based measurement techniques for the detection of atmospheric nitrogen dioxide (both in-situ and remote sensing), and to investigate their usability in satellite data validation. The expected outcomes are recommendations regarding the operation and calibration of such instruments, retrieval settings, and observation strategies for the use in ground-based networks for air quality monitoring and satellite data validation. Twenty-four optical spectrometers participated in the campaign, of which twenty-one had the capability to scan different elevation angles consecutively, the so-called Multi-axis DOAS systems, thereby collecting vertical profile information, in particular for nitrogen dioxide and aerosol. Various in-situ samplers and lidar instruments simultaneously characterized the variability of atmospheric trace gases and the physical properties of aerosol particles. A large data set of continuous measurements of these atmospheric constituents has been collected under various meteorological conditions and air pollution levels. Together with the permanent measurement capability at the CESAR site characterizing the meteorological state of the atmosphere, the CINDI campaign provided a comprehensive observational data set of atmospheric constituents in a highly polluted region of the world during summertime. First detailed comparisons performed with the CINDI data show that slant column measurements of NO2, O4 and HCHO with MAX-DOAS agree within 5 to 15%, vertical profiles of NO2 derived from several independent instruments agree within 25% of one another, and MAX-DOAS aerosol optical thickness agrees within 20-30% with AERONET data. For the in-situ NO2 instrument using a molybdenum converter, a bias was found as large as 5 ppbv during day time, when compared to the other in-situ instruments using photolytic converters

Quality of focused thoracic ultrasound performed by emergency medical technicians and paramedics in a prehospital setting:a feasibility study

BACKGROUND: In a prehospital setting, the severity of respiratory symptoms in patients calling for an ambulance differ. The initial evaluation, diagnosing, and thereby management can be challenging because respiratory symptoms can be caused by disease in many organs. Ultrasound examinations can contribute with important information and support the clinical decision-making. However, ultrasound is user-dependent and requires sufficient knowledge and training. The aim of this study was to explore the quality of thoracic ultrasound examinations performed on patients by emergency medical technicians and paramedics in a prehospital, clinical setting.METHODS: From November 2018 - April 2020, Danish emergency medical technicians and paramedics (n = 100) performed thoracic ultrasound examinations on patients with respiratory symptoms using a portable ultrasound device. The ultrasound examinations were stored and retrospectively assessed by a reviewer blinded to the patients' symptoms and history, as well as the emergency medical technicians' and paramedics' findings. The image quality was scored from 1 to 5. The findings determined by the reviewer was then correlated with a questionnaire filled out by the emergency medical technicians and paramedics regarding ultrasonic findings and potential change in treatment or management of the patient. The agreement in percentage and as Cohen's kappa was explored.RESULTS: A total of 590 ultrasound examinations were assessed, resulting in a median image quality score of 3 (IQ1 = 4, IQ3 = 3). The overall agreement in percentage between the emergency medical technicians and paramedics and reviewer was high (87.7% for a normal scan, 89.9% for interstitial syndrome, 97.3% for possible pneumothorax, and 96.3% for pleural effusion). Cohen's kappa varied from 0.01 for possible pneumothorax to 0.69 for pleural effusion. Based on the questionnaires (n = 406), the ultrasound examination entailed a change in treatment or visitation in 48 cases (11.7%) which in this study population encompasses a number-needed-to-scan of 8.5.CONCLUSION: Emergency medical technicians and paramedics perform focused thoracic ultrasound examinations with adequate image quality sufficient to determine if pathology is present or not. The emergency medical technicians' and paramedics' assessment correlates to some extent with an experienced reviewer and their findings are most reliable for the inclusion of a normal scan or inclusion of pleural effusion. Implementation could possibly impact the number of patients receiving correct prehospital treatment and optimal choice of receiving facility.</p

Patients' perspectives on point-of-care diagnostics and treatment by emergency medical technicians in acute COPD exacerbations:A qualitative study

BACKGROUND: In Denmark emergency medical technicians transport patients with acute COPD exacerbations to the nearest emergency department. From a clinical and economic perspective, this transport and assessment at the hospital may be inconvenient if the patient is immediately discharged from the emergency department. We established an emergency technical technicians point-of-care diagnostics and treatment program of patients with COPD with use of ultrasound and blood analysis. Patients' perspectives on treatment at home and sense of security are important to qualify clinical practice at home with patients with acute exacerbation.AIM AND OBJECTIVES: To explore patient's and relatives' experience of treatment at home during emergency calls due to COPD in exacerbation and to investigate their attitude to avoid hospitalization as well as experience of stress during point-of-care diagnostics in their own home.METHOD: A qualitative study comprising semi-structured interviews with 16 patients carried out from April 1st, 2019 to March 31st, 2020 in Denmark. Data was analysed inspired by Malteruds' text condensation and informed by Critical Psychology with first person perspective focusing on the patient's views on point-of-care diagnostics and treatment of their COPD in acute exacerbation.RESULTS: The interviews revealed that in order to ensure an experience of quality in the assessment and treatment of patients in their own homes, it was important that the ambulance staff showed great safety and experience in the use of the technical equipment and treatment of dyspnea. It was also of importance that the patients felt confident that their general practitioner followed up on the home treatment initiated.CONCLUSION: Patients' perspectives showed that point-of-care diagnostics and treatment of acute COPD in exacerbation was considered a qualitative offer by the patients and their relatives. At the same time, it was crucial that the emergency medical technicians showed experience and safety in handling shortness of breath as well as the technical equipment.TRIAL REGISTRATION: Approved by the Danish Data Protection Agency Project-ID: 20/24845.</p