The mysteries of mammatus clouds: Observations and formation mechanisms

Mammatus clouds are an intriguing enigma of atmospheric fluid dynamics and cloud physics. Most commonly observed on the underside of cumulonimbus anvils, mammatus also occur on the underside of cirrus, cirrocumulus, altocumulus, altostratus, and stratocumulus, as well as in contrails from jet aircraft and pyrocumulus ash clouds from volcanic eruptions. Despite their aesthetic appearance, mammatus have been the subject of few quantitative research studies. Observations of mammatus have been obtained largely through serendipitous opportunities with a single observing system (e.g., aircraft penetrations, visual observations, lidar, radar) or tangential observations from field programs with other objectives. Theories describing mammatus remain untested, as adequate measurements for validation do not exist because of the small distance scales and short time scales of mammatus. Modeling studies of mammatus are virtually nonexistent. As a result, relatively little is known about the environment, formation mechanisms, properties, microphysics, and dynamics of mammatus. This paper presents a review of mammatus clouds that addresses these mysteries. Previous observations of mammatus and proposed formation mechanisms are discussed. These hypothesized mechanisms are anvil subsidence, subcloud evaporation/sublimation, melting, hydrometeor fallout, cloud-base detrainment instability, radiative effects, gravity waves, Kelvin-Helmholtz instability, Rayleigh-Taylor instability, and Rayleigh-Bénard-like convection. Other issues addressed in this paper include whether mammatus are composed of ice or liquid water hydrometeors, why mammatus are smooth, what controls the temporal and spatial scales and organization of individual mammatus lobes, and what are the properties of volcanic ash clouds that produce mammatus? The similarities and differences between mammatus, virga, stalactites, and reticular clouds are also discussed. Finally, because much still remains to be learned, research opportunities are described for using mammatus as a window into the microphysical, turbulent, and dynamical processes occurring on the underside of clouds. © 2006 American Meteorological Society

Tolerability and Efficacy of a Pediatric Granule Formulation of Artesunate-Mefloquine in Young Children from Cameroon with Uncomplicated Falciparum Malaria

A fixed-dose pediatric formulation of artesunate and mefloquine (Artequin Pediatric) has been developed. In this open, non-comparative study in Cameroonian children with uncomplicated falciparum malaria, the safety and efficacy of this formulation was tested, with a particular emphasis on the risk of neuropsychiatric adverse events (AEs). In total, 220 subjects, weighing between 10 and 20 kg, were enrolled; 213 qualified for analysis. Artesunate-mefloquine was given once daily for 3 days. Overall, 13.1% of patients reported mild to moderate neuropsychiatric AEs (elicited through a structured questionnaire or reported spontaneously) out of which 3.8% (mainly insomnia) were considered drug-related. Other drug-related AEs were infrequent (< 3%). Polymerase chain reaction-corrected cure rate (adequate clinical and parasitological response) determined by survival analysis at 28 and 63 days was 96.6%. New infections were observed in 11.2% of evaluable patients at 63 days. The new formulation was well tolerated and efficacious in the population investigated

Meeting Report: Aging Research and Drug Discovery

Aging is the single largest risk factor for most chronic diseases, and thus possesses large socioeconomic interest to continuously aging societies. Consequently, the field of aging research is expanding alongside a growing focus from the industry and investors in aging research. This year's 8th Annual Aging Research and Drug Discovery ARDD) meeting was organized as a hybrid meeting from August 30th to September 3rd 2021 with more than 130 attendees participating on-site at the Ceremonial Hall at University of Copenhagen, Denmark, and 1800 engaging online. The conference comprised of presentations from 75 speakers focusing on new research in topics including mechanisms of aging and how these can be modulated as well as the use of AI and new standards of practices within aging research. This year, a longevity workshop was included to build stronger connections with the clinical community