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.

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.

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.

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.

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 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.

Using 3D geometric morphometrics to aid taxonomic and ecological understanding of a recent speciation event within a small Australian marsupial (Antechinus: Dasyuridae)

Taxonomic distinction of species forms the foundation of biodiversity assessments and conservation priorities. However, traditional morphological and/or genetics-based taxonomic assessments frequently miss the opportunity of elaborating on the ecological and functional context of species diversification. Here, we used 3D geometric morphometrics of the cranium to improve taxonomic differentiation and add ecomorphological characterization of a young cryptic divergence within the carnivorous marsupial genus Antechinus. Specifically, we used 168 museum specimens to characterize the recently proposed clades A. stuartii ‘south’, A. stuartii ‘north’ and A. subtropicus. Beyond slight differences attributable to overall size (and, therefore, not necessarily diagnostic), we also found clear allometry-independent shape variation. This allowed us to define new, easily measured diagnostic traits in the palate, which differentiate the three clades. Contrary to previous suggestions, we found no support for a latitudinal gradient as causing the differentiation between the clades. However, skull shape co-varied with temperature and precipitation seasonality, suggesting that the clades may be adapted to environmental variables that are likely to be impacted by climate change. Our study demonstrates the use of 3D geometric morphometrics to improve taxonomic diagnosis of cryptic mammalian species, while providing perspectives on the adaptive origins and potential future threats of mammalian diversity.

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.

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.

Integrative taxonomic investigation of Petaurus breviceps (Marsupialia: Petauridae) reveals three distinct species

The Australian sugar glider, Petaurus breviceps s.l., is widely distributed across eastern and northern Australia. Examination of historical and contemporary collections of Petaurus specimens and phylogenetic analyses have revealed considerable taxonomic diversity within the genus. We aimed to utilize an integrative taxonomic approach, combining genetic and morphological evidence, to resolve the taxonomy of Australian gliders currently recognized as Petaurus breviceps. Herein, we confirm the existence of three distinct species: P. breviceps, P. notatus comb. nov. and P. ariel comb. nov.. Petaurus breviceps and P. notatus are each represented by major mtDNA lineages in P. breviceps, while P. ariel forms a sister-lineage to P. norfolcensis and P. gracilis. Subtle morphological differences distinguish P. breviceps from the closely related P. notatus, while the morphological distinctions between P. ariel and its genetically similar sister-taxa, P. norfolcensis and P. gracilis, are more obvious. Given the purported broad geographic distribution of the taxon, P. breviceps s.l. was not listed as threatened, but dividing this taxon into three species has important conservation implications for all taxa in the group, particularly given the lamentable record for mammal extinctions in Australia. Concerted and targeted conservation efforts are necessary to preserve these distinct, newly described species.

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.

A tail of evolution: evaluating body length, weight and locomotion as potential drivers of tail length scaling in Australian marsupial mammals

Although mammalian tail length relative to body length is considered indicative of locomotor mode, this association has been difficult to quantify. This could be because the counterweight function of the tail might associate it more with body weight than body length. Alternatively, relative tail length might not be evolutionarily flexible owing to its integration with the remaining skeleton, particularly the spine. Using comparative analyses of morphological means and ranges in Australian marsupials, including the first co-assessment with body weight, our study supports the second hypothesis, i.e. tail length ranges within species, and tail lengths among species are explained better by body length than by body weight. However, all three variables do not differ in phylogenetic signal or rates of evolution. Associations of tail lengths with locomotion are limited, but suggest that scaling slopes, rather than intercepts, are responsible for limited divergence between relative tail lengths at different locomotor modes. This complicates (palaeo-)ecological interpretations of tail length further. We conclude that relative tail length is not a strong predictor of locomotor mode, probably owing to strong integration of tail and body length. The many well-documented bony and soft-tissue adaptations of tails are likely to be better suited to interpretations of locomotor adaptations.

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 (tRNA^Lys), and a non-coding control region (CR) – and gene arrangement are consistent with previous marsupial mitogenome assemblies.

Does human endometrial LGR5 gene expression suggest the existence of another hormonally regulated epithelial stem cell niche?

STUDY QUESTION

Is human endometrial leucine-rich repeat-containing G-protein-coupled receptor 5 (LGR5) gene expression limited to the postulated epithelial stem cell niche, stratum basalis glands, and is it hormonally regulated?

SUMMARY ANSWER

LGR5 expressing cells are not limited to the postulated stem cell niche but LGR5 expression is hormonally regulated.

WHAT IS KNOWN ALREADY

The human endometrium is a highly regenerative tissue; however, endometrial epithelial stem cell markers are yet to be confirmed. LGR5 is a marker of stem cells in various epithelia.

STUDY DESIGN, SIZE, DURATION

The study was conducted at a University Research Institute. Endometrial samples from 50 healthy women undergoing benign gynaecological surgery with no endometrial pathology at the Liverpool Women's hospital were included and analysed in the following six sub-categories; proliferative, secretory phases of menstrual cycle, postmenopausal, those using oral and local progestagens and samples for in vitro explant culture.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In this study, we used the gold standard method, in situ hybridisation (ISH) along with qPCR and a systems biology approach to study the location of LGR5 gene expression in full thickness human endometrium and Fallopian tubes. The progesterone regulation of endometrial LGR5 was examined in vivo and in short-term cultured endometrial tissue explants in vitro. LGR5 expression was correlated with epithelial proliferation (Ki67), and expression of previously reported epithelia progenitor markers (SOX9 and SSEA-1) immunohistochemistry (IHC).

MAIN RESULTS AND THE ROLE OF CHANCE

LGR5 gene expression was significantly higher in the endometrial luminal epithelium than in all other epithelial compartments in the healthy human endometrium, including the endometrial stratum basalis (P < 0.05). The strongest SSEA-1 and SOX9 staining was observed in the stratum basalis glands, but the general trend of SOX9 and SSEA-1 expression followed the same cyclical pattern of expression as LGR5. Stratum functionalis epithelial Ki67-LI and LGR5 expression levels correlated significantly (r = 0.74, P = 0.01), however, they did not correlate in luminal and stratum basalis epithelium (r = 0.5 and 0.13, respectively). Endometrial LGR5 demonstrates a dynamic spatiotemporal expression pattern, suggesting hormonal regulation. Oral and local progestogens significantly reduced endometrial LGR5 mRNA levels compared with women not on hormonal treatment (P < 0.01). Our data were in agreement with in silico analysis of published endometrial microarrays.

LARGE SCALE DATA

We did not generate our own large scale data but interrogated publically available large scale data sets.

LIMITATIONS, REASONS FOR CAUTION

In the absence of reliable antibodies for human LGR5 protein and validated lineage markers for the various epithelial populations that potentially exist within the endometrium, our study does not formally characterise or examine the functional ability of the resident LGR5+ cells as multipotent.

WIDER IMPLICATIONS OF THE FINDINGS

These data will facilitate future lineage tracing studies in the human endometrial epithelium; to identify the location of stem cells and further complement the in vitro functional studies, to confirm if the LGR5 expressing epithelial cells indeed represent the epithelial stem cell population.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by funding from the Wellbeing of Women project grant (RTF510) and Cancer Research UK (A14895). None of the authors have any conflicts of interest to disclose.

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.

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.

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.

Phylogenetic Diversity (PD) and Biodiversity Conservation: Some Bioinformatics Challenges

Biodiversity conservation addresses information challenges through estimations encapsulated in measures of diversity. A quantitative measure of phylogenetic diversity, “PD”, has been defined as the minimum total length of all the phylogenetic branches required to span a given set of taxa on the phylogenetic tree (Faith 1992a). While a recent paper incorrectly characterizes PD as not including information about deeper phylogenetic branches, PD applications over the past decade document the proper incorporation of shared deep branches when assessing the total PD of a set of taxa. Current PD applications to macroinvertebrate taxa in streams of New South Wales, Australia illustrate the practical importance of this definition. Phylogenetic lineages, often corresponding to new, “cryptic”, taxa, are restricted to a small number of stream localities. A recent case of human impact causing loss of taxa in one locality implies a higher PD value for another locality, because it now uniquely represents a deeper branch. This molecular-based phylogenetic pattern supports the use of DNA barcoding programs for biodiversity conservation planning. Here, PD assessments side-step the contentious use of barcoding-based “species” designations. Bioinformatics challenges include combining different phylogenetic evidence, optimization problems for conservation planning, and effective integration of phylogenetic information with environmental and socioeconomic 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.

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).

Dietary composition and prey preference of a new carnivorous marsupial species, the buff-footed antechinus (Antechinus mysticus), at the northern and southern limits of its range

The buff-footed antechinus (Antechinus mysticus) is a newly described carnivorous marsupial from eastern Australia. We examined the diet composition and prey preference of this little known dasyurid in the southernmost (Brisbane) and northernmost (Eungella) populations. Animals were captured over three months (July–September) during 2014 encompassing the breeding period (late July and August) of the species. Seasonal sampling carried over into a second year which followed the succeeding cohort of juveniles as they dispersed from their maternal nest (summer), through their maturation (autumn), to the beginning of breeding (winter), sampling across one complete generation. The diet of A. mysticus consisted predominantly of invertebrates, with 16 prey orders identified (11 Insecta, two Arachnida, two Myriapoda, one Crustacea). Vertebrate (Family Scincidae) consumption was recorded in low abundance at both sites. The diet of A. mysticus was dominated by Araneae (spiders), Blattodea (cockroaches) and Coleoptera (beetles). Comparison of identified prey consumption in scats with prey availability in pitfall traps showed A. mysticus to be a dietary generalist, opportunistically consuming mostly invertebrate prey with supplementary predation on small vertebrates. Juvenile A. mysticus preyed predominantly on Blattodea (33.4% mean percentage volume) and Coleoptera (31.6% mean percentage volume), potentially suggesting a preference for larger, easier to catch, prey items. Further exploration into the relationship between prey and body size is required to determine this.

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.

Benefits of being a generalist carnivore when threatened by climate change: the comparative dietary ecology of two sympatric semelparous marsupials, including a new endangered species (Antechinus arktos)

The endangered black-tailed dusky antechinus (Antechinus arktos) was described in 2014, so most aspects of its ecology are unknown. We examined diet composition and prey selection of A. arktos and a sympatric congener, the northern form of A. stuartii, at two sites in Springbrook National Park. Overall, taxa from 25 invertebrate orders were identified in the diets from 252 scat samples. Dietary components were similar for each species, but A. arktos consumed a higher frequency and volume of dipteran larvae and Diplopoda, while A. stuartii consumed more Coleoptera, Lepidoptera, Orthoptera and Isopoda. Both species of Antechinus had a higher percentage of ‘empty’ scats (devoid of any identifiable invertebrate material) in 2014 compared with 2015. The former was a drier year overall. Lower rainfall may have reduced abundance and diversity of arthropod prey, causing both species to supplement their diet with soft-bodied prey items such as earthworms, which are rarely detected in scats. Comparison of prey in scats with invertebrate captures from pitfall traps showed both species to be dietary generalists, despite exhibiting distinct preference and avoidance of certain prey categories. The ability of an endangered generalist marsupial to switch prey may be particularly advantageous considering the anticipated effects of climate change on Gondwanan rainforests during the mid-late 21st century.

The Perfect Murder: How a Suicide Became a Homicide

This case report describes the death of a 51-year-old female, which presented by autopsy, scene circumstances, and social history as a suicidal ligature hanging. However, when her boyfriend walked into a police department in another state, months later, claiming to have killed the woman and staged a hanging, the medical examiner's office was asked to review the admission, as it was thought wholly inconsistent with the timeline provided. Upon reenactment of the admission, the perpetrator perfectly demonstrated the use of a lateral vascular neck restraint (carotid restraint), known to incapacitate and potentially kill an individual within a matter of seconds. The autopsy finding of severe atherosclerotic heart disease was important in understanding the mechanism of death, the timeline of events, and in corroborating the confession. This case demonstrates the value of performing an autopsy even though investigation and history suggested an obvious cause and manner of death.

Suicide by Hypothermia: A Report of Two Cases and 23-Year Retrospective Review

Hypothermia deaths are frequently accidental and associated with impairment by alcohol, injuries, mental illness, or natural disease. Hypothermia as a method of suicide is unusual, with only nine case reports in the scientific literature. In the early months of 2014, during one of the coldest winters on record, the Hennepin County Medical Examiner's office investigated and certified two unrelated cases of suicide by hypothermia; we describe the salient features of these cases. A retrospective review of all cases investigated by our office from January 1991-April 2014 identified 146 cases in which “hypothermia” or “environmental cold exposure” was listed as a cause of death, contributing condition, or mechanism of injury. Death investigation narratives and autopsy reports were reviewed to confirm hypothermia and evaluate for the presence or absence of characteristic hypothermia findings. In these cases the manner of death was certified as follows: 116 accident (79.4%), 15 undetermined (10.3%), 8 suicide (5.5%), 6 natural (4.1%), and 1 homicide (0.7%). Further examination of the eight suicide cases revealed that half were female and half were male, and most were younger individuals with only one decedent above 50 years of age. Four of these deaths were associated with drug toxicities, five were associated with additional self-inflicted injuries (blunt force, sharp force, and/or gunshot wounds), and none of them exhibited paradoxical undressing. It is important for medicolegal death investigation professionals to recognize that, while rare, hypothermia deaths may represent intentional injury, and suicide as a manner of death should be considered in all cases.

Cerebral Toxoplasmosis Presenting as a Medical Examiner Case

Toxoplasma gondii is a common parasite, with infection rates ranging from 16–40% of the United States population to up to 80% in some Central and South American and European countries. Clinically significant toxoplasmosis is considerably rarer, primarily affecting those with compromised immune systems. In the era of widespread human immunodeficiency virus (HIV) testing and effective HIV therapies, toxoplasmosis is rarely encountered in the medical examiner setting. We report a case of previously undiagnosed cerebral toxoplasmosis in a prisoner not known to be HIV-positive, who was hospitalized and treated for a presumed head injury. Manifestations of toxoplasmosis, pathology, treatment, and outcomes are discussed. This case highlights the need for thorough autopsies not only for deaths apparently resulting from injuries in jails and correctional institutions, but also when prisoners are hospitalized for seemingly benign reasons, yet the cause of death remains unclear despite clinical evaluation and treatment.

Establishing a Multidisciplinary Network for the Workup of Sudden Cardiac Death

Sudden cardiac death (SCD) often falls under the jurisdiction of the medical examiner (ME). A recent expert consensus statement recommends cardiac evaluation for all first degree blood relatives of an individual with SCD and supports the referral of these family members to a multidisciplinary inherited arrhythmia clinic; however, most MEs lack the appropriate clinical network for a specific referral and family members are often not followed up. In 2010, Minnesota MEs and cardiovascular pathologists began collaborating with a cardiology referral center specializing in familial cardiac conditions to form a regional Sudden Death Network (SDN). The cardiac pathologists and MEs have established protocols for appropriate specimen retention in accordance with the National Association of Medical Examiners position paper on postmortem deoxyribonucleic acid (DNA) collection and for referring families for clinical evaluation. The expertise of a genetic counselor has been essential to the evaluation of these families in coordinating appropriate genetic testing and assisting with the identification of at-risk family members in extended pedigrees. This SDN uses a multidisciplinary approach for referral of family members for screening and treatment of SCD risk and represents an important resource for MEs. Development of SDNs across the country would lead to a more uniform approach to SCD follow-up and a more efficient use of clinical resources. The ME's role is essential in consulting cardiac pathologists when needed, establishing the correct diagnosis, collecting and retaining appropriate specimens, and initiating the referral of at-risk family members to specialists.

Prey of the silver-headed antechinus (Antechinus argentus), a new species of Australian dasyurid marsupial

The silver-headed antechinus (Antechinus argentus) is one of Australia’s most recently described mammals, and the single known population at Kroombit Tops in south-east Queensland is threatened. Nothing is known of the species’ ecology, so during 2014 we collected faecal pellets each month (March–September) from a population at the type locality to gather baseline data on diet composition. A total of 38 faecal pellets were collected from 12 individuals (eight females, four males) and microscopic analysis of pellets identified seven invertebrate orders, with 70% combined mean composition of beetles (Coleoptera: 38%) and cockroaches (Blattodea: 32%). Other orders that featured as prey were ants, crickets/grasshoppers, butterflies/moths, spiders, and true bugs. Given that faecal pellets could only be collected from a single habitat type (Eucalyptus montivaga high-altitude open forest) and location, this is best described as a generalist insectivorous diet that is characteristic of other previously studied congeners.

Overview of the Organization of Scientific Area Committees

The National Institute of Standards and Technologies (NIST) has transformed the majority of the Scientific Working Groups (SWGs) into the Organization of Scientific Area Committees (OSAC). The OSAC has been created to foster the development of standards and guidelines for the practice of documenting evidence by methods that are technically sound and accepted by the consensus of forensic practitioners. The OSAC is composed of 33 committees arranged in a hierarchy. Potential standards begin in a Subcommittee and must work their way through approval by the Subcommittee, the Subcommittee's parent Scientific Area Committee (SAC), and finally the Forensic Science Standards Board (FSSB) before being adopted into the FSSB Registry of Approved Standards. NIST hopes to find existing standards with technical merit that were developed through a standards development process for adoption as national standards of practice. The OSAC provides forensic scientists the unprecedented opportunity of validating their own scientific practices within the framework of sound scientific practice.

Phase segregation of sulfonate groups in Nafion interface lamellae, quantified via neutron reflectometry fitting techniques for multi-layered structures

Neutron reflectometry analysis methods for under-determined, multi-layered structures are developed and used to determine the composition depth profile in cases where the structure is not known a priori. These methods, including statistical methods, sophisticated fitting routines, and coupling multiple data sets, are applied to hydrated and dehydrated Nafion nano-scaled films with thicknesses comparable to those found coating electrode particles in fuel cell catalyst layers. These results confirm the lamellar structure previously observed on hydrophilic substrates, and demonstrate that for hydrated films they can accurately be described as layers rich in both water and sulfonate groups alternating with water-poor layers containing an excess of fluorocarbon groups. The thickness of these layers increases slightly and the amplitude of the water volume fraction oscillation exponentially decreases away from the hydrophilic interface. For dehydrated films, the composition oscillations die out more rapidly. The Nafion-SiO2 substrate interface contains a partial monolayer of sulfonate groups bonded to the substrate and a large excess of water compared to that expected by the water-to-sulfonate ratio, λ, observed throughout the rest of the film. Films that were made thin enough to truncate this lamellar region showed a depth profile nearly identical to thicker films, indicating that there are no confinement or surface effects altering the structure. Comparing the SLD profile measured for films dried at 60 °C to modeled composition profiles derived by removing water from the hydrated lamellae suggests incomplete re-mixing of the polymer groups upon dehydration, indicated limited polymer mobility in these Nafion thin films.

Conservation genetics of the water mouse, Xeromys myoides Thomas, 1889

The water mouse, Xeromys myoides, is currently recognised as a vulnerable species in Australia, inhabiting a small number of distinct and isolated coastal regions of Queensland and the Northern Territory. An examination of the evolutionary history and contemporary influences shaping the genetic structure of this species is required to make informed conservation management decisions. Here, we report the first analysis undertaken on the phylogeography and population genetics of the water mouse across its mainland Australian distribution. Genetic diversity was assessed at two mitochondrial DNA (Cytochrome b, 1000 bp; D-loop, 400 bp) and eight microsatellite DNA loci. Very low genetic diversity was found, indicating that water mice underwent a recent expansion throughout their Australian range and constitute a single evolutionarily significant unit. Microsatellite analyses revealed that the highest genetic diversity was found in the Mackay region of central Queensland; population substructure was also identified, suggesting that local populations may be isolated in this region. Conversely, genetic diversity in the Coomera region of south-east Queensland was very low and the population in this region has experienced a significant genetic bottleneck. These results have significant implications for future management, particularly in terms of augmenting populations through translocations or reintroducing water mice in areas where they have gone extinct.

Taxonomy and redescription of the Atherton Antechinus, Antechinus godmani (Thomas) (Marsupialia: Dasyuridae)

We provide a taxonomic redescription of the dasyurid marsupial Atherton Antechinus, Antechinus godmani (Thomas). A. godmani is only rarely encountered and limited to wet tropical rainforests of north-east Queensland, Australia, between the towns of Cardwell and Cairns (a distribution spanning 135 kilometres from north to south). The distinctive species occurs at altitudes of over 600 meters asl, in all major rainforest types, and can be found with both the northern subspecies of the Yellow-footed Antechinus, A. flavipes rubeculus Van Dyck and the Rusty Antechinus, A. adustus (Thomas). A. godmani is clearly separated from all congeners on the basis of both morphometrics and genetics. A. godmani can be distinguished from all extant congeners based on external morphology by a combination of large size, naked-looking tail and reddish fur on the face and head. A. godmani skulls are characteristically large, with a suite of long features: basicranium, palate, upper premolar tooth row, inter-palatal vacuity distance and dentary. Phylogenies generated from mt- and nDNA data position Antechinus godmani as monophyletic with respect to other members of the genus; A. godmani is strongly supported as the sister-group to a clade containing all other antechinus, but excluding the south-east Australian Dusky Antechinus, A. swainsonii (Waterhouse) and Swamp Antechinus, A. minimus (Geoffroy). Antechinus godmani are genetically very divergent compared to all congeners (mtDNA: range 12.9-16.3%).

Unexpected Death from Hemorrhagic Pericarditis Complicating IgA Nephropathy

IgA nephropathy is the most common cause of glomerulonephritis in the developed world; however, it is usually an indolent or slowly progressive disease presenting initially as self-limited hematuria, typically following a viral or bacterial infection. We report a case of previously undiagnosed IgA nephropathy manifesting with end stage renal disease, fibrinous pericarditis, and hemorrhagic pericardial effusion in a 26-year-old white male. Clinical manifestations of IgA nephropathy, the presumed pathogenesis, and complications are reviewed. This case highlights the importance of interdisciplinary collaborations with other specialized pathology services—in this case renal pathology, including direct immunofluorescence and electron microscopy—that may not be routinely available or used in forensic pathology practices. In this instance, such collaboration provided the etiologically specific diagnosis for an unusual presentation of a common disease.

Molecular phylogeny supports the paraphyletic nature of the genus Trogoderma (Coleoptera: Dermestidae) collected in the Australasian ecozone

To date, a molecular phylogenetic approach has not been used to investigate the evolutionary structure of Trogoderma and closely related genera. Using two mitochondrial genes, Cytochrome Oxidase I and Cytochrome B, and the nuclear gene, 18S, the reported polyphyletic positioning of Trogoderma was examined. Paraphyly in Trogoderma was observed, with one Australian Trogoderma species reconciled as sister to all Dermestidae and the Anthrenocerus genus deeply nested within the Australian Trogoderma clade. In addition, time to most recent common ancestor for a number of Dermestidae was calculated. Based on these estimations, the Dermestidae origin exceeded 175 million years, placing the origins of this family in Pangaea.