Research Perspectives: Improving Action Research by Integrating Methods

Action research (AR) has developed extensively since the 1970s. We reviewed the AR literature within the information systems (IS) discipline and found 16 different methods, which constitutes a problematic situation for researchers. We describe and critique those methods before integrating their strengths to improve the AR method that is most frequently practiced in IS: canonical action research (CAR). The existing set of principles and criteria for CAR is modified and elaborated to enhance the foundation for undertaking AR consistently. We discuss the general implications of this improved form of the method, which we name integrated action research (IAR). We specifically suggest how IAR can be used to investigate the application of disruptive technologies, including those that embody artificial intelligence and enable more flexible and socially distanced work

Neutron scattering study of the long-range ordered state in CeRu2Al10

Elastic and inelastic neutron scattering measurements have been performed on powder and single-crystal samples of orthorhombic CeRu2Al10. The order forming below T0 = 27 K was identified as a long-range antiferromagnetic state with the wave vector k = (1,0,0). The magnetic spectral response in the ordered phase, measured on powder, is characterized by a spin gap and a pronounced peak at 8 meV, whose Q dependence suggests a magnetic origin. Both features are suppressed when temperature is raised to T0, and a conventional relaxational behavior is observed at 40 K. This peculiar spin dynamics is discussed in connection with recent magnetization results for the same compound.Comment: 5 pages, 5 figures, International Conference on Heavy Electrons 2010 (Tokyo Metropolitan University, September 17 - 20, 2010), to be published in Journal of the Physical Society of Japan. Typo corrected p. 3: "sites denoted 1 and 3" => "1 and 4

The Community-Driven Approach to Environmental Exposures: How a Community-Based Participatory Research Program Analyzing Impacts of Environmental Exposure on Lupus Led to a Toxic Site Cleanup

Community-based participatory research (CBPR) is a mechanism to improve environmental quality in communities primarily inhabited by minorities or low income families. A collaborative partnership between the University at Buffalo and the Toxic Waste Lupus Coalition was formed to investigate the high prevalence of lupus in the area and whether cases of disease were linked to chemicals found at a nearby New York State Superfund site in East Buffalo. The purpose of the study was to use CBPR practices to educate impacted residents and enable their participation in efforts to get a nearby contaminated waste site remediated. Community members were active participants in the development of the plan to clean up the toxic site. These methods can be used to better engage the community in research and involve them in actions taken to improve their neighborhood

Limiting absorption principle for the dissipative Helmholtz equation

Adapting Mourre's commutator method to the dissipative setting, we prove a limiting absorption principle for a class of abstract dissipative operators. A consequence is the resolvent estimates for the high frequency Helmholtz equation when trapped trajectories meet the set where the imaginary part of the potential is non-zero. We also give the resolvent estimates in Besov spaces

Orbits for the Impatient: A Bayesian Rejection Sampling Method for Quickly Fitting the Orbits of Long-Period Exoplanets

We describe a Bayesian rejection sampling algorithm designed to efficiently compute posterior distributions of orbital elements for data covering short fractions of long-period exoplanet orbits. Our implementation of this method, Orbits for the Impatient (OFTI), converges up to several orders of magnitude faster than two implementations of MCMC in this regime. We illustrate the efficiency of our approach by showing that OFTI calculates accurate posteriors for all existing astrometry of the exoplanet 51 Eri b up to 100 times faster than a Metropolis-Hastings MCMC. We demonstrate the accuracy of OFTI by comparing our results for several orbiting systems with those of various MCMC implementations, finding the output posteriors to be identical within shot noise. We also describe how our algorithm was used to successfully predict the location of 51 Eri b six months in the future based on less than three months of astrometry. Finally, we apply OFTI to ten long-period exoplanets and brown dwarfs, all but one of which have been monitored over less than 3% of their orbits, producing fits to their orbits from astrometric records in the literature.Comment: 32 pages, 28 figures, Accepted to A

Radio masers on WX UMa : hints of a Neptune-sized planet, or magnetospheric reconnection?

RDK acknowledges funding received from the Irish Research Council (IRC) through the Government of Ireland Postgraduate Scholarship Programme. RDK and AAV acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 817540, ASTROFLOW). We acknowledge the provisions of the Space Weather Modelling Framework (SWMF) code from the Center for Space Environment Modeling (CSEM) at the University of Michigan, and the computational resources of the Irish Centre for High End Computing (ICHEC), both of which were utilised in this work.The nearby M dwarf WX UMa has recently been detected at radio wavelengths with LOFAR. The combination of its observed brightness temperature and circular polarisation fraction suggests that the emission is generated via the electron-cyclotron maser instability. Two distinct mechanisms have been proposed to power such emission from low-mass stars: either a sub-Alfvénic interaction between the stellar magnetic field and an orbiting planet, or reconnection at the edge of the stellar magnetosphere. In this paper, we investigate the feasibility of both mechanisms, utilising the information about the star’s surrounding plasma environment obtained from modelling its stellar wind. Using this information, we show that a Neptune-sized exoplanet with a magnetic field strength of 10 – 100 G orbiting at ∼0.034 au can accurately reproduce the observed radio emission from the star, with corresponding orbital periods of 7.4 days. Due to the stellar inclination, a planet in an equatorial orbit is unlikely to transit the star. While such a planet could induce radial velocity semi-amplitudes from 7 to 396 m s−1, it is unlikely that this signal could be detected with current techniques due to the activity of the host star. The application of our planet-induced radio emission model here illustrates its exciting potential as a new tool for identifying planet-hosting candidates from long-term radio monitoring. We also develop a model to investigate the reconnection-powered emission scenario. While this approach produces less favourable results than the planet-induced scenario, it nevertheless serves as a potential alternative emission mechanism which is worth exploring further.PostprintPeer reviewe

Out-of-equilibrium states as statistical equilibria of an effective dynamics

We study the formation of coherent structures in a system with long-range interactions where particles moving on a circle interact through a repulsive cosine potential. Non equilibrium structures are shown to correspond to statistical equilibria of an effective dynamics, which is derived using averaging techniques. This simple behavior might be a prototype of others observed in more complicated systems with long-range interactions, like two-dimensional incompressible fluids or self-gravitating systems.Comment: 4 figure

Facteurs Prédictifs de Survenue de la Fibrillation Auriculaire à L’origine des Accidents Vasculaires Cérébraux Ischémiques Auprès du Service de Neurologie de Befalatanana, Antananarivo

La fibrillation auriculaire (FA) est la première cause des infarctus cérébraux cardio-emboliques. Cette étude a pour objet d'identifier les facteurs prédictifs des FA à l'origine des accidents vasculaires ischémiques cardio-emboliques auprès du service de Neurologie de Befelatanana. Il s’agit d’une étude rétrospective, descriptive, transversale à visée analytique sur 24 mois, allant du 01 janvier 2018 jusqu’au 31 décembre 2019. Nous avons retenu 93 patients avec une recherche de FA au cours de l’hospitalisation. L’âge en moyen est de 64 ans ± 14,1 ans avec un sex-ratio à 1,325. Les principaux facteurs de risque cardiovasculaire identifiés étaient l’hypertension artérielle (77,41%) ; le tabagisme (36,55 %) ; l’antécédent d’AVC (29,03%) ; l’antécédent d’une insuffisance cardiaque et/ou de cardiopathies (19,35%), le diabète sucré (10,75%). L’âge supérieur à 65 ans (p=0.048 ; OR  1.919 (1.012-3.639)) et l’antécédent d’une HTA (p=0.034 ; OR à 2.831 (0.964-8.310)) sont les facteurs prédictifs cliniques identifiés dans la survenue d’une FA. Les anomalies à l’échodoppler cardiaque les plus retrouvées étaient l’altération de la FEVG (26,88%) ; la dilatation de l’oreillette gauche (5,37%) ; le thrombus intracardiaque (4,3%).  Aucun de ces paramètres n’était pas associé à la survenue de FA dans notre étude. Cette étude confirme la nécessité de rechercher systématiquement la FA chez les sujets âgés et les patients hypertendus afin de débuter un traitement adéquat pour une meilleure prévention primaire et secondaire des infarctus cérébraux.   Atrial fibrillation (AF) is the leading cause of cardioembolic cerebral infarction. The purpose of this study is to identify the predictive factors of AF at the origin of cardio-embolic ischemic vascular accidents in the Neurology department of Befelatanana. This is a retrospective, descriptive, cross-sectional study with an analytical aim over 24 months, from January 1, 2018 to December 31, 2019. We retained 93 patients with a search for AF during hospitalization. The average age is 64 ± 14.1 years with a sex ratio of 1.325. The main cardiovascular risk factors identified were high blood pressure (77.41%); smoking (36.55%); history of stroke (29.03%); history of heart failure and/or heart disease (19.35%), diabetes mellitus (10.75%). Age over 65 (p=0.048; OR 1.919 (1.012-3.639)) and history of hypertension (p=0.034; OR 2.831 (0.964-8.310)) are the clinical predictive factors identified in the occurrence of AF. The most common cardiac echo-doppler abnormalities were altered LVEF (26.88%); dilation of the left atrium (5.37%); intracardiac thrombus (4.3%). None of these parameters was associated with the occurrence of AF in our study. This study confirms the need to systematically search for AF in elderly subjects and hypertensive patients in order to start adequate treatment for better primary and secondary prevention of cerebral infarction

Facteurs Prédictifs de Survenue de la Fibrillation Auriculaire à L’origine des Accidents Vasculaires Cérébraux Ischémiques Auprès du Service de Neurologie de Befalatanana, Antananarivo

La fibrillation auriculaire (FA) est la première cause des infarctus cérébraux cardio-emboliques. Cette étude a pour objet d'identifier les facteurs prédictifs des FA à l'origine des accidents vasculaires ischémiques cardio-emboliques auprès du service de Neurologie de Befelatanana. Il s’agit d’une étude rétrospective, descriptive, transversale à visée analytique sur 24 mois, allant du 01 janvier 2018 jusqu’au 31 décembre 2019. Nous avons retenu 93 patients avec une recherche de FA au cours de l’hospitalisation. L’âge en moyen est de 64 ans ± 14,1 ans avec un sex-ratio à 1,325. Les principaux facteurs de risque cardiovasculaire identifiés étaient l’hypertension artérielle (77,41%) ; le tabagisme (36,55 %) ; l’antécédent d’AVC (29,03%) ; l’antécédent d’une insuffisance cardiaque et/ou de cardiopathies (19,35%), le diabète sucré (10,75%). L’âge supérieur à 65 ans (p=0.048 ; OR  1.919 (1.012-3.639)) et l’antécédent d’une HTA (p=0.034 ; OR à 2.831 (0.964-8.310)) sont les facteurs prédictifs cliniques identifiés dans la survenue d’une FA. Les anomalies à l’échodoppler cardiaque les plus retrouvées étaient l’altération de la FEVG (26,88%) ; la dilatation de l’oreillette gauche (5,37%) ; le thrombus intracardiaque (4,3%).  Aucun de ces paramètres n’était pas associé à la survenue de FA dans notre étude. Cette étude confirme la nécessité de rechercher systématiquement la FA chez les sujets âgés et les patients hypertendus afin de débuter un traitement adéquat pour une meilleure prévention primaire et secondaire des infarctus cérébraux.   Atrial fibrillation (AF) is the leading cause of cardioembolic cerebral infarction. The purpose of this study is to identify the predictive factors of AF at the origin of cardio-embolic ischemic vascular accidents in the Neurology department of Befelatanana. This is a retrospective, descriptive, cross-sectional study with an analytical aim over 24 months, from January 1, 2018 to December 31, 2019. We retained 93 patients with a search for AF during hospitalization. The average age is 64 ± 14.1 years with a sex ratio of 1.325. The main cardiovascular risk factors identified were high blood pressure (77.41%); smoking (36.55%); history of stroke (29.03%); history of heart failure and/or heart disease (19.35%), diabetes mellitus (10.75%). Age over 65 (p=0.048; OR 1.919 (1.012-3.639)) and history of hypertension (p=0.034; OR 2.831 (0.964-8.310)) are the clinical predictive factors identified in the occurrence of AF. The most common cardiac echo-doppler abnormalities were altered LVEF (26.88%); dilation of the left atrium (5.37%); intracardiac thrombus (4.3%). None of these parameters was associated with the occurrence of AF in our study. This study confirms the need to systematically search for AF in elderly subjects and hypertensive patients in order to start adequate treatment for better primary and secondary prevention of cerebral infarction