Electrical charging of ash in Icelandic volcanic plumes

The existence of volcanic lightning and alteration of the atmospheric potential gradient in the vicinity of near-vent volcanic plumes provides strong evidence for the charging of volcanic ash. More subtle electrical effects are also visible in balloon soundings of distal volcanic plumes. Near the vent, some proposed charging mechanisms are fractoemission, triboelectrification, and the so-called "dirty thunderstorm" mechanism, which is where ash and convective clouds interact electrically to enhance charging. Distant from the vent, a self-charging mechanism, probably triboelectrification, has been suggested to explain the sustained low levels of charge observed on a distal plume. Recent research by Houghton et al. (2013) linked the self-charging of volcanic ash to the properties of the particle size distribution, observing that a highly polydisperse ash distribution would charge more effectively than a monodisperse one. Natural radioactivity in some volcanic ash could also contribute to self-charging of volcanic plumes. Here we present laboratory measurements of particle size distributions, triboelectrification and radioactivity in ash samples from the Gr\'{i}msv\"{o}tn and Eyjafjallaj\"{o}kull volcanic eruptions in 2011 and 2010 respectively, and discuss the implications of our findings.Comment: XV Conference on Atmospheric Electricity, 15-20 June 2014, Norman, Oklahoma, US

Geobiology and sedimentology of the hypersaline Great Salt Lake, Northern Utah, USA: analogues for assessing watery environments on Mars?

Journal ArticleThe hypersaline Great Salt Lake (GSL) of northern Utah, USA is a critical regional ecosystem that has not been examined in detail from a geobiological perspective. There are presently only a handful of studies on the biota of this shallow water closed-lake system [1]. Despite interest from industries mining the salt and harvesting the brine shrimp, relatively little is known about the lake?s geochemistry, microbial diversity, metabolic activity, and mineralogy, and how these relate together with processes of biosedimentation and fossil preservation

Investigating the biochemical signatures and physiological roles of the FMO family using molecular phylogeny

Group B flavin-dependent monooxygenases are employed in swathes of different physiological functions. Despite their collectively large substrate profile, they all harness a flavin-based C4a-(hydro)peroxy intermediate for function. Within this class are the flavin-containing monooxygenases (FMOs), representing an integral component within the secondary metabolism of all living things – xenobiotic detoxification. Their broad substrate profile makes them ideal candidates for detoxifying procedures as they can tackle a range of compounds. Recent studies have illustrated that several FMOs, however, have unique substrate profiles and differing physiological functions that implicate new roles within secondary and primary metabolism. Herein this article, by employing phylogenetic approaches, and inspecting structures of AlphaFold generated models, we have constructed a biochemical blueprint of the FMO family. FMOs are clustered in four distinct groups, with two being predominantly dedicated to xenobiotic detoxification. Furthermore, we observe that differing enzymatic activities are not constricted to a ‘golden’ set of residues but instead an intricate constellation of primary and secondary sphere residues. We believe that this work delineates the core phylogeny of the Group B monooxygenases and will prove useful for classifying newly sequenced genes and provide directions to future biochemical investigations.</p

The effectiveness of semantic intervention for word-finding difficulties in college-aged students (16–19 years) with persistent Language Disorder

BACKGROUND AND AIMS: Little evidence exists for the effectiveness of intervention for older adolescents and young adults with language disorders, particularly for those over 16 years. This study involves college-aged students aged 16–19 years with Language Disorder and Word-Finding Difficulties and investigates whether progress in word finding following 1:1 semantic intervention is greater than progress during a baseline period as measured by a standardised test. METHODS: Twenty-five college-aged students (20 males and 5 females) with Language Disorder and Word-Finding Difficulties (aged 16;4–18;4 years) participated in a single baseline design study comparing progress on the Test of Adolescent and Adult Word Finding during an intervention period with progress during a baseline period of equal length. Intervention was focused on semantics of different words from those in the Test of Adolescent and Adult Word Finding and was delivered 1:1 by the participants’ usual Speech and Language Therapist, 30 minutes per week, for eight weeks. RESULTS: The participants made significant progress in raw score on the Test of Adolescent and Adult Word Finding during both the baseline (d = 1.4) and intervention (d = 2.5) periods, but progress during the intervention period was significantly greater than during the baseline period (d = 1.16). Individual data showed reliable change for five participants during the baseline period and for 20 participants during the intervention period. At the start of the study, all participants had standard scores below 85, but after intervention, 10/25 participants scored above 85. CONCLUSIONS: Four hours of semantic intervention led to significantly greater gains on a standardised test of word finding than during a baseline period of equal length in 16–19 year olds with Language Disorder and Word-Finding Difficulties. The words in the standardised test had not been included in the intervention, indicating generalised gains. IMPLICATIONS: This study shows that intervention (at least for Word-Finding Difficulties) can be effective for this older age group of college-aged students with Language Disorder and therefore the effectiveness of Speech and Language Therapy services for this age group in a wider range of areas of language should also be investigated

Investigating the biochemical signatures and physiological roles of the FMO family using molecular phylogeny

Group B flavin-dependent monooxygenases are employed in swathes of different physiological functions. Despite their collectively large substrate profile, they all harness a flavin-based C4a-(hydro)peroxy intermediate for function. Within this class are the flavin-containing monooxygenases (FMOs), representing an integral component within the secondary metabolism of all living things – xenobiotic detoxification. Their broad substrate profile makes them ideal candidates for detoxifying procedures as they can tackle a range of compounds. Recent studies have illustrated that several FMOs, however, have unique substrate profiles and differing physiological functions that implicate new roles within secondary and primary metabolism. Herein this article, by employing phylogenetic approaches, and inspecting structures of AlphaFold generated models, we have constructed a biochemical blueprint of the FMO family. FMOs are clustered in four distinct groups, with two being predominantly dedicated to xenobiotic detoxification. Furthermore, we observe that differing enzymatic activities are not constricted to a ‘golden’ set of residues but instead an intricate constellation of primary and secondary sphere residues. We believe that this work delineates the core phylogeny of the Group B monooxygenases and will prove useful for classifying newly sequenced genes and provide directions to future biochemical investigations.</p