Comparative Studies of Atomically Thin Proton Conductive Films to Reduce Crossover in Hydrogen Fuel Cells.

Hydrogen fuel cells based on proton exchange membrane fuel cell (PEMFC) technology are promising as a source of clean energy to power a decarbonized future. However, PEMFCs are limited by a number of major inefficiencies; one of the most significant is hydrogen crossover. In this work, we comprehensively study the effects of two-dimensional (2D) materials applied to the anode side of the membrane as H2 barrier coatings on Nafion to reduce crossover effects on hydrogen fuel cells, while studying adverse effects on conductivity and catalyst performance in the beginning of life testing. The barrier layers studied include graphene, hexagonal boron nitride (hBN), amorphous boron nitride (aBN), and varying thicknesses of molybdenum disulfide (MoS2), all chosen due to their expected stability in a fuel cell environment. Crossover mitigation in the materials studied ranges from 4.4% (1 nm MoS2) to 46.1% (graphene) as compared to Nafion 211. Effects on proton conductivity are also studied, suggesting high areal proton transport in materials previously thought to be effectively nonconductive, such as 2 nm MoS2 and amorphous boron nitride under the conditions studied. The results indicate that a number of 2D materials are able to improve crossover effects, with those coated with 8 nm MoS2 and 1 L graphene able to achieve greater crossover reduction while minimizing conductivity penalty.

Hiding in plain sight: two new species of diminutive marsupial (Dasyuridae: Planigale) from the Pilbara, Australia.

Many of Australias smaller marsupial species have been taxonomically described in just the past 50 years, and the Dasyuridae, a speciose family of carnivores, is known to harbour many cryptic taxa. Evidence from molecular studies is being increasingly utilised to help revise species boundaries and focus taxonomic efforts, and research over the past two decades has identified several undescribed genetic lineages within the dasyurid genus Planigale. Here, we describe two new species, Planigale kendricki sp. nov. (formerly known as Planigale 1) and P. tealei sp. nov. (formerly known as Planigale sp. Mt Tom Price). The two new species have broadly overlapping distributions in the Pilbara region of Western Australia. The new species are genetically distinct from each other and from all other members of the genus, at both mitochondrial and nuclear loci, and morphologically, in both external and craniodental characters. The new species are found in regional sympatry within the Pilbara but occupy different habitat types at local scales. This work makes a start at resolving the cryptic diversity within Planigale at a time when small mammals are continuing to decline throughout Australia.

An analysis of child suicide from three centers (2008-2017).

Although the overall suicide rate worldwide has changed minimally over the past 100 years, different trends have been observed over time in the USA, Australia, and New Zealand (NZ). However, few studies have focused on suicides in children (< 18 years), making evaluation of possible trends difficult. The last 20 years has also seen an increase in childhood obesity, eating disorders, and body image issues for children in many developed nations; however, few studies have shown whether a significant proportion of child suicides have an abnormal BMI. The current study evaluates child suicides (from 2008 to 2017) in South Australia (Australia), compared with the jurisdictions of Auckland (NZ) and Hennepin County (USA). Demographic data (age, sex, ethnicity), body mass index (BMI), the number of cases of youth suicide, and the method of suicide from these three regions were collected and analyzed. Across the 10-year period, the jurisdiction of Auckland had a downward trend, while Hennepin County and South Australia had increasing numbers of cases. The most common method of child suicide in all centers was hanging, occurring in > 80% of cases in South Australia and Auckland and 56% in Hennepin County. Hennepin County had a greater proportion of suicides using firearms (28%), compared to 1.9% in Auckland and 5.1% in South Australia. Unusual means of suicide were used less frequently by youth than previously.

Expert range maps of global mammal distributions harmonised to three taxonomic authorities.

Aim: Comprehensive, global information on species' occurrences is an essential biodiversity variable and central to a range of applications in ecology, evolution, biogeography and conservation. Expert range maps often represent a species' only available distributional information and play an increasing role in conservation assessments and macroecology. We provide global range maps for the native ranges of all extant mammal species harmonised to the taxonomy of the Mammal Diversity Database (MDD) mobilised from two sources, the Handbook of the Mammals of the World (HMW) and the Illustrated Checklist of the Mammals of the World (CMW). Location: Global. Taxon: All extant mammal species. Methods: Range maps were digitally interpreted, georeferenced, error-checked and subsequently taxonomically aligned between the HMW (6253 species), the CMW (6431 species) and the MDD taxonomies (6362 species). Results: Range maps can be evaluated and visualised in an online map browser at Map of Life (mol.org) and accessed for individual or batch download for non-commercial use. Main conclusion: Expert maps of species' global distributions are limited in their spatial detail and temporal specificity, but form a useful basis for broad-scale characterizations and model-based integration with other data. We provide georeferenced range maps for the native ranges of all extant mammal species as shapefiles, with species-level metadata and source information packaged together in geodatabase format. Across the three taxonomic sources our maps entail, there are 1784 taxonomic name differences compared to the maps currently available on the IUCN Red List website. The expert maps provided here are harmonised to the MDD taxonomic authority and linked to a community of online tools that will enable transparent future updates and version control.

Autoerotic Death by Electrocution: An Atypical Case Study.

ABSTRACT: Autoerotic death is defined as an accidental death that occurs when some type of apparatus is used to enhance sexual stimulation and causes an unintended death. We present the case of an atypical autoerotic death of a 23-year-old man found deceased in a bathroom. An electrical cord with a standard wall plug on one end and exposed wires twisted into loops on the other end was on the floor near his body. Minute black burns were present on each nipple. The outlet was protected by a ground fault circuit interrupter that was demonstrated to be in working order. An electrical consultant concluded that the cause of death could not be electrocution. Ground fault circuit interrupters work by detecting differences in current within a circuit. If a ground fault occurs, the circuit is broken to prevent a fatal electrocution. In the present case, the ground fault circuit interrupter did not shut off because the decedent had wired himself in parallel with the circuit. This, with the other scene findings, indicated this to be a case of atypical autoerotic death. Autoerotic deaths by means other than asphyxiation are rare. This case serves to illustrate the circumstances of an atypical autoerotic death by means of electrocution.

A chromosome-level genome of Antechinus flavipes provides a reference for an Australian marsupial genus with male death after mating.

The 15 species of small carnivorous marsupials that comprise the genus Antechinus exhibit semelparity, a rare life-history strategy in mammals where synchronized death occurs after one breeding season. Antechinus males, but not females, age rapidly (demonstrate organismal senescence) during the breeding season and show promise as new animal models of ageing. Some antechinus species are also threatened or endangered. Here, we report a chromosome-level genome of a male yellow-footed antechinus Antechinus flavipes. The genome assembly has a total length of 3.2 Gb with a contig N50 of 51.8 Mb and a scaffold N50 of 636.7 Mb. We anchored and oriented 99.7% of the assembly on seven pseudochromosomes and found that repetitive DNA sequences occupy 51.8% of the genome. Draft genome assemblies of three related species in the subfamily Phascogalinae, two additional antechinus species (Antechinus argentus and A. arktos) and the iteroparous sister species Murexia melanurus, were also generated. Preliminary demographic analysis supports the hypothesis that climate change during the Pleistocene isolated species in Phascogalinae and shaped their population size. A transcriptomic profile across the A. flavipes breeding season allowed us to identify genes associated with aspects of the male die-off. The chromosome-level A. flavipes genome provides a steppingstone to understanding an enigmatic life-history strategy and a resource to assist the conservation of antechinuses.

A new molecular phylogeny for the Tanypodinae (Diptera: Chironomidae) places the Australian diversity in a global context.

The non-biting midge subfamily Tanypodinae (Diptera: Chironomidae) is species-rich, ecologically diverse, and near-globally distributed. Within the subfamily, aspects of generic and species-level taxonomy remain poorly understood, in particular the validity of assignment of Australian and New Zealand taxa to genera erected for northern hemisphere (Holarctic) fauna. Here, we place the austral diversity within this global context by extensive geographical and taxonomic sampling in concert with a multilocus phylogenetic approach. We incorporated sequence data for mitochondrial COI, and nuclear 28S and CAD, and conducted Bayesian and maximum likelihood phylogenetic inferences and Bayesian divergence time estimation. The resolved phylogeny supported many associations of Australian taxa with their proposed Holarctic congeners, with the exception of Apsectrotanypus Fittkau, and validates several taxa as endemic. Three of four New Zealand sampled taxa had their sister groups in Australia; New Zealand Monopelopia Fittkau was sister to a German congener. This included the first record of Procladius Kieffer from New Zealand. Most nodes connecting austral and Holarctic taxa clustered around the Cretaceous-Tertiary boundary (60-80 mya), whereas New Zealand-Australia nodes were generally slightly younger (53-57 mya). Together, these data contribute substantially to our understanding of the taxonomy, systematics and biogeography of the Australian Tanypodinae and more broadly to knowledge of Australia's aquatic insect biodiversity.

A Chromosome-Level Genome of the Agile Gracile Mouse Opossum (Gracilinanus agilis).

There are more than 100 species of American didelphid marsupials (opossums and mouse opossums). Limited genomic resources for didelphids exists, with only two publicly available genome assemblies compared with dozens in the case of their Australasian counterparts. This discrepancy impedes evolutionary and ecological research. To address this gap, we assembled a high-quality chromosome-level genome of the agile gracile mouse opossum (Gracilinanus agilis) using a combination of stLFR sequencing, polishing with mate-pair data, and anchoring onto pseudochromosomes using Hi-C. This species employs a rare life-history strategy, semelparity, and all G. agilis males and most females die at the end of their first breeding season after succumbing to stress and exhaustion. The 3.7-Gb chromosome-level assembly, with 92.6% anchored onto pseudochromosomes, has a scaffold N50 of 683.5 Mb and a contig N50 of 56.9 kb. The genome assembly shows high completeness, with a mammalian BUSCO score of 88.1%. Around 49.7% of the genome contains repetitive elements. Gene annotation yielded 24,425 genes, of which 83.9% were functionally annotated. The G. agilis genome is an important resource for future studies of marsupial biology, evolution, and conservation.

Molecular evidence for deeper diversity in Australian Tanypodinae (Chironomidae): Yarrhpelopia and related new taxa.

The diversity and endemism of Australian Tanypodinae (Diptera: Chironomidae) has been unclear from morphological comparisons with well-grounded northern hemisphere taxonomy. As part of a comprehensive study, here we focus on one of the few described endemic genera, Yarrhpelopia Cranston. Extensive and intensive new sampling and newly-acquired molecular data provides clarity for the type species, Yarrhpelopia norrisi Cranston and allows recognition of congeners and potential sister group(s). We describe Yarrhpelopia acorona Cranston Krosch sp. n., and we recognise a third species from Western Australia, retaining an informal code 'V20' due to inadequate reared / associated material for formal description. We recognise a robust clade Coronapelopia Cranston Krosch gen. n., treated as a genus new to science for two new species, Coronapelopia valedon Cranston Krosch sp. n. and Coronapelopia quadridentata Cranston Krosch sp. n., from eastern Australia, each described in their larval and pupal stages and partial imaginal stages. Interleaved between the independent new Australian clades Yarrhpelopia and Coronapelopia are New World Pentaneura and relatives, that allow a tentative inference of a dated gondwanan (austral) connection. Expanded sampling indicates that Y. norrisi, although near predictably present in mine-polluted waters, is not obligate but generally indicates acidic waters, including natural swamps and Sphagnum bogs. The inferred acidophily, including in drainages of mine adits, applies to many taxa under consideration here.

Vegetation structure and ground cover attributes describe the occurrence of a newly discovered carnivorous marsupial on the Tweed Shield Volcano caldera, the endangered black-tailed dusky antechinus (Antechinus arktos).

The black-tailed dusky antechinus (Antechinus arktos) is a recently discovered, endangered, carnivorous marsupial mammal endemic to the Tweed Shield Volcano caldera, straddling the border between Queensland and New South Wales in eastern Australia. The species' preference for cool, high-altitude habitats makes it particularly vulnerable to a shifting climate as these habitats recede. Aside from basic breeding and dietary patterns, the species' ecology is largely unknown. Understanding fine-scale habitat attributes preferred by this endangered mammal is critical to employ successful conservation management. Here, we assess vegetation attributes of known habitats over three sites at Springbrook and Border Ranges National Parks, including detailed structure data and broad floristic assessment. Floristic compositional assessment of the high-altitude cloud rainforest indicated broad similarities. However, only 22% of plant species were shared between all sites indicating a high level of local endemism. This suggests a diverse assemblage of vegetation across A. arktos habitats. Habitat characteristics were related to capture records of A. arktos to determine potential fine-scale structural habitat requirements. Percentage of rock cover and leaf litter were the strongest predictors of A. arktos captures across survey sites, suggesting a need for foraging substrate and cover. Habitat characteristics described here will inform predictive species distribution models of this federally endangered species and are applicable to other mammal conservation programs.

Determining the efficacy of camera traps, live capture traps, and detection dogs for locating cryptic small mammal species.

Metal box (e.g., Elliott, Sherman) traps and remote cameras are two of the most commonly employed methods presently used to survey terrestrial mammals. However, their relative efficacy at accurately detecting cryptic small mammals has not been adequately assessed. The present study therefore compared the effectiveness of metal box (Elliott) traps and vertically oriented, close range, white flash camera traps in detecting small mammals occurring in the Scenic Rim of eastern Australia. We also conducted a preliminary survey to determine effectiveness of a conservation detection dog (CDD) for identifying presence of a threatened carnivorous marsupial, Antechinus arktos, in present-day and historical locations, using camera traps to corroborate detections. 200 Elliott traps and 20 white flash camera traps were set for four deployments per method, across a site where the target small mammals, including A. arktos, are known to occur. Camera traps produced higher detection probabilities than Elliott traps for all four species. Thus, vertically mounted white flash cameras were preferable for detecting the presence of cryptic small mammals in our survey. The CDD, which had been trained to detect A. arktos scat, indicated in total 31 times when deployed in the field survey area, with subsequent camera trap deployments specifically corroborating A. arktos presence at 100% (3) indication locations. Importantly, the dog indicated twice within Border Ranges National Park, where historical (1980s-1990s) specimen-based records indicate the species was present, but extensive Elliott and camera trapping over the last 5-10 years have resulted in zero A. arktos captures. Camera traps subsequently corroborated A. arktos presence at these sites. This demonstrates that detection dogs can be a highly effective means of locating threatened, cryptic species, especially when traditional methods are unable to detect low-density mammal populations.

The mitochondrial genome of the black-tailed dusky antechinus (Antechinus arktos).

In this study, we report the mitochondrial genome of the black-tailed antechinus (Antechinus arktos), a recently-discovered, endangered carnivorous marsupial inhabiting a caldera that straddles the border of Australia's mid-east coast. The circular A. arktos genome is 17,334 bp in length and has an AT content of 63.3%. Its gene content and arrangement are consistent with reported marsupial mitogenome assemblies.

The mitochondrial genome of the black-tailed dasyure (Murexia melanurus).

In this study, we report the mitochondrial genome of the black-tailed dasyure (Murexia melanurus) of New Guinea. The circular genome is 17,736 bp in length and has an AT content of 60.5%. Its gene content - 13 protein-coding genes (PCGs), 2 ribosomal (rRNA) genes, 21 transfer RNA (tRNA) genes, a tRNA pseudogene (tRNALys ), and a non-coding control region (CR) - and gene arrangement are consistent with previous marsupial mitogenome assemblies.

RadAA: A Command-line Tool for Identification of Radical Amino Acid Changes in Multiple Sequence Alignments.

High-throughput sequencing has revolutionised biology and medicine. Numerous genomes and transcriptome assemblies are now available, and these genomic data sets lend themselves to comparisons between species, strains, and other strata. Researchers often need to rapidly identify changes, in particular amino acid substitutions that could confer biological function in their system of interest. However, we are not aware of an easy-to-use tool that can be used to detect such changes, and researchers currently rely on idiosyncratic computer code. We present RadAA, a command-line tool which screens multiple sequence alignments for radical amino acid changes in a stratum/strata by classifying residues into groups by charge (with cysteine in its own group). RadAA is easy to use, even for researchers with little experience in computational biology. It can be run on most operating systems - including MacOS, Windows, and Linux - and integrated into high-performance computing environments. The RadAA source code and executable binaries are freely available at https://github.com/sciseim/RadAA.

Discovered and disappearing? Conservation genetics of a recently named Australian carnivorous marsupial.

Five new species within the Australian carnivorous marsupial genus Antechinus have recently been named, at least two of which are threatened. Important facets of the habitat use and extinction risk of one of these new species, the buff-footed antechinus, A. mysticus, are not well understood. Previous research has suggested that the species utilizes a broad range of inter-connected forest habitats in southeast Queensland (Qld), Australia. Based on this potentially connected habitat, we predicted that A. mysticus should have low population genetic structure, particularly in relation to its congener, the spatially restricted, high altitude, closed-forest A. subtropicus. We genotyped nine microsatellite loci for six populations of A. mysticus, sampled throughout their known range in eastern Australia, and compared them with four proximate populations of A. subtropicus. Surprisingly, genetic structuring among southeast Qld populations of A. mysticus was moderate to high and similar to that between A. subtropicus populations. We postulate that all A. mysticus populations have declined recently (<100 generations), particularly the northernmost southeast Qld population, which may be at risk of extinction. Our results suggest that A. mysticus is limited to a more scattered and fragmented distribution than previously thought and may be in decline. The identification of population decline in this study and recently in other Antechinus suggests the extinction risk of many Australian mammals should be reassessed.

Prey productivity and predictability drive different axes of life-history variation in carnivorous marsupials.

Variation in life-history strategies has usually been characterized as a single fast-slow continuum of life-history variation, in which mean lifespan increases with age at maturity as reproductive output at each breeding event declines. Analyses of plants and animals suggest that strategies of reproductive timing can vary on an independent axis, with iteroparous species at one extreme and semelparous species at the other. Insectivorous marsupials in the Family Dasyuridae have an unusually wide range of life-history strategies on both purported axes. We test and confirm that reproductive output and degree of iteroparity are independent in females across species. Variation in reproductive output per episode is associated with mean annual rainfall, which predicts food availability. Position on the iteroparity-semelparity axis is not associated with annual rainfall, but species in regions of unpredictable rainfall have longer maximum lifespans, more potential reproductive events per year, and longer breeding seasons. We suggest that these two axes of life-history variation arise because reproductive output is limited by overall food availability, and selection for high offspring survival favours concentrated breeding in seasonal environments. Longer lifespans are favoured when reproductive opportunities are dispersed over longer periods in environments with less predictable food schedules.

Plant diversity and structure describe the presence of a new, threatened Australian marsupial within its highly restricted, post-fire habitat.

Management of critical habitat for threatened species with small ranges requires location-specific, fine-scale survey data. The silver-headed antechinus (Antechinus argentus) is known from only two isolated, fire-prone locations. At least one of these populations, at Kroombit Tops National Park in central-eastern Queensland, Australia, possesses a very small range. Here, we present detailed vegetation species diversity and structure data from three sites comprising the known habitat of A. argentus at Kroombit Tops and relate it to capture data obtained over two years. We found differences in both vegetation and capture data between burnt and unburnt habitat. Leaf litter and grasstrees (Xanthorrhoea johnsonii) were the strongest vegetative predictors for A. argentus capture. The species declined considerably over the two years of the trapping study, and we raise concern for its survival at Kroombit Tops. We suggest that future work should focus on structural vegetative variables (specifically, the diameter and leaf density of grasstree crowns) and relate them to A. argentus occurrence. We also recommend a survey of invertebrate diversity in grasstrees and leaf litter with a comparison to A. argentus prey. The data presented here illustrates how critical detailed monitoring is for planning habitat management and fire regimes, and highlights the utility of a high-resolution approach to habitat mapping. While a traditional approach to fire management contends that pyrodiversity encourages biodiversity, the present study demonstrates that some species prefer long-unburnt habitat. Additionally, in predicting the distribution of rare species like A. argentus, data quality (i.e., spatial resolution) may prevail over data quantity (i.e., number of data).

Can remote infrared cameras be used to differentiate small, sympatric mammal species? A case study of the black-tailed dusky antechinus, Antechinus arktos and co-occurring small mammals in southeast Queensland, Australia.

The black-tailed dusky antechinus (Antechinus arktos) is an endangered, small carnivorous marsupial endemic to Australia, which occurs at low population density along with abundant sympatric populations of other small mammals: Antechinus stuartii, Rattus fuscipes and Melomys cervinipes. Using A. arktos as a model species, we aimed to evaluate the effectiveness of infrared digital camera traps for detecting and differentiating small mammals and to comment on the broad applicability of this methodology. We also sought to understand how the detection probabilities of our target species varied over time and characterize their activity patterns. We installed 11 infrared cameras at one of only three known sites where A. arktos occurs for five consecutive deployments. Cameras were fixed to wooden stakes and oriented vertically, 35 cm above ground, directly facing bait containers. Using this method, we successfully recorded and identified individuals from all four species of small mammal known previously in the area from live trapping, including A. arktos. This validates the effectiveness of the infrared camera type and orientation for small mammal studies. Periods of activity for all species were highly coincident, showing a strong peak in activity during the same two-hour period immediately following sunset. A. arktos, A. stuartii and M. cervinipes also displayed a strong negative linear relationship between detection probability and days since deployment. This is an important finding for camera trapping generally, indicating that routine camera deployment lengths (of one-to-two weeks) between baiting events may be too long when targeting some small mammals.

Comparison of the Frequency of Sudden Cardiovascular Deaths in Young Competitive Athletes Versus Nonathletes: Should We Really Screen Only Athletes?

The issue of sudden death in young athletes and consideration for the most practical and optimal strategy to identify those genetic and/or congenital heart diseases responsible for these tragic events continues to be debated. However, proponents of broad-based and mandatory national preparticipation screening, including with 12-lead electrocardiograms have confined the focus to a relatively small segment of the youthful population who choose to engage in competitive athletic programs at the high school, college, and elite-professional level. Therefore, lost in this discussion of preparticipation screening of athletes is that the larger population of young people not involved in competitive sports (and, therefore, a priori are excluded from systematic screening) who nevertheless may die suddenly of the same cardiovascular diseases as athletes. To substantiate this hypothesis, we accessed the forensic Hennepin County, Minnesota registry in which cardiovascular sudden deaths were 8-fold more common in nonathletes (n = 24) than athletes (n = 3) and threefold more frequent in terms of incidence. The most common diseases responsible for sudden death were hypertrophic cardiomyopathy (n = 6) and arrhythmogenic right ventricular cardiomyopathy (n = 4). These data raise ethical considerations inherent in limiting systematic screening for unsuspected genetic and/or congenital heart disease to competitive athletes.