Voltage-Dependent Gating of hERG Potassium Channels

The mechanisms by which voltage-gated channels sense changes in membrane voltage and energetically couple this with opening of the ion conducting pore has been the source of significant interest. In voltage-gated potassium (Kv) channels, much of our knowledge in this area comes from Shaker-type channels, for which voltage-dependent gating is quite rapid. In these channels, activation and deactivation are associated with rapid reconfiguration of the voltage-sensing domain unit that is electromechanically coupled, via the S4–S5 linker helix, to the rate-limiting opening of an intracellular pore gate. However, fast voltage-dependent gating kinetics are not typical of all Kv channels, such as Kv11.1 (human ether-à-go-go related gene, hERG), which activates and deactivates very slowly. Compared to Shaker channels, our understanding of the mechanisms underlying slow hERG gating is much poorer. Here, we present a comparative review of the structure–function relationships underlying activation and deactivation gating in Shaker and hERG channels, with a focus on the roles of the voltage-sensing domain and the S4–S5 linker that couples voltage sensor movements to the pore. Measurements of gating current kinetics and fluorimetric analysis of voltage sensor movement are consistent with models suggesting that the hERG activation pathway contains a voltage independent step, which limits voltage sensor transitions. Constraints upon hERG voltage sensor movement may result from loose packing of the S4 helices and additional intra-voltage sensor counter-charge interactions. More recent data suggest that key amino acid differences in the hERG voltage-sensing unit and S4–S5 linker, relative to fast activating Shaker-type Kv channels, may also contribute to the increased stability of the resting state of the voltage sensor

The Wehl family of South Australia and their botanical connections with “Dear Uncle” Baron Ferdinand von Mueller

Dr Eduard Wehl and Clara Wehl (née Mueller) and their children hold a unique position in the history of South Australian botany because of their association with Clara’s brother and the children’s uncle, Baron Ferdinand von Mueller, Australia’s most significant botanist of the nineteenth century. Both Wehl parents and six of their twelve surviving children collected botanical specimens for Mueller and about 1200 herbarium specimens have been located with most being held in the National Herbarium of Victoria. The majority of specimens were collected in the vicinity of Mount Gambier and Lake Bonney, South Australia. As well as collecting botanical specimens, two daughters, Marie Magdalene Wehl and Henrietta Jane Wehl, illustrated plants and fungi. About 300 illustrations have survived. Of these, about 240 are of flowering plants and contained in three sketchbooks, two of which are at the National Herbarium of Victoria and one at the State Herbarium of South Australia. Marie made a speciality of illustrating fungi, and 36 illustrations are included in an album in the Natural History Museum, London, and 25 others are held as either loose illustrations or associated with herbarium specimens in the National Herbarium of Victoria. Specimens collected by the Wehls have been used in the typification of at least 23 species names. The family is commemorated in three taxa: Clara Wehl in the marine alga Gigartina wehliae Sond.; Eduard and Clara Wehl jointly in the plant genus Wehlia F.Muell. [= Homalocalyx F.Muell.]; and Marie Wehl in the fungus Agaricus wehlianus F.Muell. ex Cooke [=Pluteus wehlianus (F.Muell. ex Cooke) Sacc.]. In this paper we provide a brief history of the Wehl family in South Australia. We assess the herbarium specimens collected by them, examine their illustrations and determine the connections between them and their current importance for typification. Underlying this, we consider the contribution made by the Wehl family toward the botanical work of Baron Ferdinand von Mueller

Chapter F of the International Code of Nomenclature for algae, fungi, and plants as approved by the 11th International Mycological Congress, San Juan, Puerto Rico, July 2018

A revised version of Chapter F of the International Code of Nomenclature for algae, fungi, and plants is presented, incorporating amendments approved by the Fungal Nomenclature Session of the 11th International Mycological Congress held in San Juan, Puerto Rico in July 2018. The process leading to the amendments is outlined. Key changes in the San Juan Chapter F are (1) removal of option to use a colon to indicate the sanctioned status of a name, (2) introduction of correctability for incorrectly cited identifiers of names and typifications, and (3) introduction of option to use name identifiers in place of author citations. Examples have been added to aid the interpretation of new Articles and Recommendations, and Examples have also been added to the existing Art. F.3.7 concerning the protection extended to new combinations based on sanctioned names or basionyms of sanctioned names (which has been re-worded), and to Art. F.3.9 concerning typification of names accepted in the sanctioning works

New species of Tulasnella associated with terrestrial orchids in Australia

Recent studies using sequence data from eight sequence loci and coalescent-based species delimitation methods have revealed several species-level lineages of Tulasnella associated with the orchid genera Arthrochilus, Caleana, Chiloglottis, and Drakaea in Australia. Here we formally describe three of those species, Tulasnella prima, T. secunda, and T. warcupii spp. nov., as well as an additional Tulasnella species associated with Chiloglottis growing in Sphagnum, T. sphagneti sp. nov. Species were identified by phylogenetic analyses of the ITS with up to 1.3 % sequence divergence within taxa and a minimum of 7.6 % intraspecific divergence. These new Tulasnella (Tulasnellaceae, Cantharellales) species are currently only known from orchid hosts, with each fungal species showing a strong relationship with an orchid genus. In this study, T. prima and T. sphagneti associate with Chiloglottis, while T. secunda associates with Drakaea and Caleana, and T. warcupii associates with Arthrochilus oreophilu

Setting scientific names at all taxonomic ranks in italics facilitates their quick recognition in scientific papers

It is common practice in scientific journals to print genus and species names in italics. This is not only historical as species names were traditionally derived from Greek or Latin. Importantly, it also facilitates the rapid recognition of genus and species names when skimming through manuscripts. However, names above the genus level are not always italicized, except in some journals which have adopted this practice for all scientific names. Since scientific names treated under the various Codes of nomenclature are without exception treated as Latin, there is no reason why names above genus level should be handled differently, particularly as higher taxon names are becoming increasingly relevant in systematic and evolutionary studies and their italicization would aid the unambiguous recognition of formal scientific names distinguishing them from colloquial names. Several leading mycological and botanical journals have already adopted italics for names of all taxa regardless of rank over recent decades, as is the practice in the International Code of Nomenclature for algae, fungi, and plants, and we hereby recommend that this practice be taken up broadly in scientific journals and textbooks

Exploring the dynamics of compliance with community penalties

In this paper, we examine how compliance with community penalties has been theorized hitherto and seek to develop a new dynamic model of compliance with community penalties. This new model is developed by exploring some of the interfaces between existing criminological and socio-legal work on compliance. The first part of the paper examines the possible definitions and dimensions of compliance with community supervision. Secondly, we examine existing work on explanations of compliance with community penalties, supplementing this by drawing on recent socio-legal scholarship on private individuals’ compliance with tax regimes. In the third part of the paper, we propose a dynamic model of compliance, based on the integration of these two related analyses. Finally, we consider some of the implications of our model for policy and practice concerning community penalties, suggesting the need to move beyond approaches which, we argue, suffer from compliance myopia; that is, a short-sighted and narrowly focused view of the issues

Solving the taxonomic identity of Pseudotomentella tristis s.l. (Thelephorales, Basidiomycota) – a multi-gene phylogeny and taxonomic review, integrating ecological and geographical data

P. tristis is an ectomycorrhizal, corticioid fungus whose name is frequently assigned to collections of basidiomata as well as root tip and soil samples from a wide range of habitats and hosts across the northern hemisphere. Despite this, its identity is unclear; eight heterotypic taxa have in major reviews of the species been considered synonymous with or morphologically similar to P. tristis, but no sequence data from type specimens have been available. With the aim to clarify the taxonomy, systematics, morphology, ecology and geographical distribution of P. tristis and its morphologically similar species, we studied their type specimens as well as 147 basidiomata collections of mostly North European material. We used gene trees generated in BEAST 2 and PhyML and species trees estimated in STACEY and ASTRAL to delimit species based on the ITS, LSU, Tef1α and mtSSU regions. We enriched our sampling with environmental ITS sequences from the UNITE database. We found the P. tristis group to contain 13 molecularly and morphologically distinct species. Three of these, P. tristis, P. umbrina and P. atrofusca, are already known to science, while ten species are here described as new: P. sciastra sp. nov., P. tristoides sp. nov., P. umbrinascens sp. nov., P. pinophila sp. nov., P. alnophila sp. nov., P. alobata sp. nov., P. pluriloba sp. nov., P. abundiloba sp. nov., P. rotundispora sp. nov. and P. media sp. nov. We discovered P. rhizopunctata and P. atrofusca to form a sister clade to all other species in P. tristis s.l. These two species, unlike all other species in the P. tristis complex, are dimitic. In this study, we designate epitypes for P. tristis, P. umbrina and Hypochnopsis fuscata and lectotypes for Auricularia phylacteris and Thelephora biennis. We show that the holotype of Hypochnus sitnensis and the lectotype of Hypochnopsis fuscata are conspecific with P. tristis, but in the absence of molecular information we regard Pseudotomentella longisterigmata and Hypochnus rhacodium as doubtful taxa due to their aberrant morphology. We confirm A. phylacteris, Tomentella biennis and Septobasidium arachnoideum as excluded taxa, since their morphology clearly show that they belong to other genera. A key to the species of the P. tristis group is provided. We found P. umbrina to be a common species with a wide, Holarctic distribution, forming ectomycorrhiza with a large number of host species in habitats ranging from tropical forests to the Arctic tundra. The other species in the P. tristis group were found to be less common and have narrower ecological niches

Candidate regulators of Early Leaf Development in Maize Perturb Hormone Signalling and Secondary Cell Wall Formation When Constitutively Expressed in Rice

All grass leaves are strap-shaped with a series of parallel veins running from base to tip, but the distance between each pair of veins, and the cell-types that develop between them, differs depending on whether the plant performs C or C photosynthesis. As part of a multinational effort to introduce C traits into rice to boost crop yield, candidate regulators of C leaf anatomy were previously identified through an analysis of maize leaf transcriptomes. Here we tested the potential of 60 of those candidate genes to alter leaf anatomy in rice. In each case, transgenic rice lines were generated in which the maize gene was constitutively expressed. Lines grouped into three phenotypic classes: (1) indistinguishable from wild-type; (2) aberrant shoot and/or root growth indicating possible perturbations to hormone homeostasis; and (3) altered secondary cell wall formation. One of the genes in class 3 defines a novel monocot-specific family. None of the genes were individually sufficient to induce C -like vein patterning or cell-type differentiation in rice. A better understanding of gene function in C plants is now needed to inform more sophisticated engineering attempts to alter leaf anatomy in C plants

Factors that shape pedagogical practices in next generation learning spaces

International figures on university expenditure on the development of next generation learning spaces (NGLS) are not readily available but anecdote suggests that simply retrofitting an existing classroom as an NGLS conservatively costs $AUD200,000, while developing new buildings often cost in the region of 100 million dollars and over the last five years, many universities in Australia, Europe and North America have developed new buildings. Despite this considerable investment, it appears that the full potential of these spaces is not being realised. While researchers argue that a more student centred learning approach to teaching has inspired the design of next generation learning spaces (Tom, Voss, & Scheetz, 2008) and that changed spaces change practice (Joint Information Systems Committee, 2009) when 'confronted' with a next generation learning spaces for the first time, anecdotes suggest that many academics resort to teaching as they have always taught and as they were taught. This chapter highlights factors that influence teaching practices, showing that they are to be found in the external, organisational and personal domains. We argue that in order to fully realise significant improvements in student outcomes through the sector's investment in next generation learning spaces, universities need to provide holistic and systematic support across three domains - the external, the organisational and the personal domains, by changing policies, systems, procedures and localised practices to better facilitate changes in teaching practices that maximise the potential of next generation learning spaces

Instant detection of synthetic cannabinoids on physical matrices, implemented on a low-cost, ultraportable device

Synthetic cannabinoids (SCs) make up a class of novel psychoactive substances (NPS), used predominantly in prisons and homeless communities in the U.K. SCs can have severe side effects, including psychosis, stroke, and seizures, with numerous reported deaths associated with their use. The chemical diversity of SCs presents the major challenge to their detection since approaches relying on specific molecular recognition become outdated almost immediately. Ideally one would have a generic approach to detecting SCs in portable settings. The problem of SC detection is more challenging still because the majority of SCs enter the prison estate adsorbed onto physical matrices such as paper, fabric, or herb materials. That is, regardless of the detection modality used, the necessary extraction step reduces the effectiveness and ability to rapidly screen materials on-site. Herein, we demonstrate a truly instant generic test for SCs, tested against real-world drug seizures. The test is based on two advances. First, we identify a spectrally silent region in the emission spectrum of most physical matrices. Second, the finding that background signals (including from autofluorescence) can be accurately predicted is based on tracking the fraction of absorbed light from the irradiation source. Finally, we demonstrate that the intrinsic fluorescence of a large range of physical substrates can be leveraged to track the presence of other drugs of interest, including the most recent iterations of benzodiazepines and opioids. We demonstrate the implementation of our presumptive test in a portable, pocket-sized device that will find immediate utility in prisons and law enforcement agencies around the world