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The on‐going anthropogenic degradation of freshwater habitats has drastically altered the environmental supply of both nutrients and common pollutants. Most organisms living in these altered habitats experience interactive effects of various stressors that can initiate adjustments at multiple levels impacting their fitness. Hence, studies measuring response to a single environmental parameter fail to capture the complexities of the status quo. We tested both the individual and the interactive effect of arsenic (As) exposure, food quantity, and dietary phosphorus (P)‐supply on six life‐history traits (Juvenile Growth Rate; Adult Growth Rate; Age and Size at Maturity, Lifespan, and Fecundity) as surrogates for organismal fitness in the keystone aquatic grazer Daphnia pulex. We also tested the effect of food quantity and P‐supply on somatic As accumulation in Daphnia. Our results indicated an influence of P‐supply on neonatal growth and an influence of As and food quantity on growth and maintenance later in life. Maturation was strongly influenced by all three variables, with no reproduction observed in the presence of two or more environmental stressors. We found a strong interaction between As and dietary P, with increased P‐supply intensifing the toxicity effect of As. No such effects were seen between As and food quantity, indicating a differential role of quantity versus quality on As toxicity. We found a nominal effect of diet on somatic As accumulation. The results from the present study emphasize the importance of considering such interactions between co‐occurring environmental stressors and the dietary status of organisms, to better predict and manage impacts and risks associated with common environmental toxicants in highly vulnerable ecosystems. Environ Toxicol Chem 2024;43:1807–1819. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

The koala, one of the most iconic Australian wildlife species, is facing several concomitant threats that are driving population declines. Some threats are well known and have clear methods of prevention (e.g., habitat loss can be reduced with stronger land‐clearing control), whereas others are less easily addressed. One of the major current threats to koalas is chlamydial disease, which can have major impacts on individual survival and reproduction rates and can translate into population declines. Effective management strategies for the disease in the wild are currently lacking, and, to date, we know little about the determinants of individual susceptibility to disease. Here, we investigated the genetic basis of variation in susceptibility to chlamydia using one of the most intensively studied wild koala populations. We combined data from veterinary examinations, chlamydia testing, genetic sampling and movement monitoring. Out of our sample of 342 wild koalas, 60 were found to have chlamydia. Using genotype information on 5007 SNPs to investigate the role of genetic variation in determining disease status, we found no evidence of inbreeding depression, but a heritability of 0.11 (95% CI: 0.06–0.23) for the probability that koalas had chlamydia. Heritability of susceptibility to chlamydia could be relevant for future disease management, as it suggests adaptive potential for the population. [ABSTRACT FROM AUTHOR]

Effective conservation requires accurate data on population genetic diversity, inbreeding, and genetic structure. Increasingly, scientists are adopting genetic non‐invasive sampling (gNIS) as a cost‐effective population‐wide genetic monitoring approach. gNIS has, however, known limitations which may impact the accuracy of downstream genetic analyses. Here, using high‐quality single nucleotide polymorphism (SNP) data from blood/tissue sampling of a free‐ranging koala population (n = 430), we investigated how the reduced SNP panel size and call rate typical of genetic non‐invasive samples (derived from experimental and field trials) impacts the accuracy of genetic measures, and also the effect of sampling intensity on these measures. We found that gNIS at small sample sizes (14% of population) can provide accurate population diversity measures, but slightly underestimated population inbreeding coefficients. Accurate measures of internal relatedness required at least 33% of the population to be sampled. Accurate geographic and genetic spatial autocorrelation analysis requires between 28% and 51% of the population to be sampled. We show that gNIS at low sample sizes can provide a powerful tool to aid conservation decision‐making and provide recommendations for researchers looking to apply these techniques to free‐ranging systems. [ABSTRACT FROM AUTHOR]

Habitat destruction and fragmentation are increasing globally, forcing surviving species into small, isolated populations. Isolated populations typically experience heightened inbreeding risk and associated inbreeding depression and population decline; although individuals in these populations may mitigate these risks through inbreeding avoidance strategies. For koalas, as dietary specialists already under threat in the northern parts of their range, increased habitat fragmentation and associated inbreeding costs are of great conservation concern. Koalas are known to display passive inbreeding avoidance through sex‐biased dispersal, although population isolation will reduce dispersal pathways. We tested whether free‐ranging koalas display active inbreeding avoidance behaviours. We used VHF tracking data, parentage reconstruction, and veterinary examination results to test whether free‐ranging female koalas avoid mating with (a) more closely related males; and (b) males infected with sexually transmitted Chlamydia pecorum. We found no evidence that female koalas avoid mating with relatively more related available mates. In fact, as the relatedness of potential mates increases, so did inbreeding events. We also found no evidence that female koalas can avoid mating with males infected with C. pecorum. The absence of active inbreeding avoidance mechanisms in koalas is concerning from a conservation perspective, as small, isolated populations may be at even higher risk of inbreeding depression than expected. At risk koala populations may require urgent conservation interventions to augment gene flow and reduce inbreeding risks. Similarly, if koalas are not avoiding mating with individuals with chlamydial disease, populations may be at higher risk from disease than anticipated, further impacting population viability. [ABSTRACT FROM AUTHOR]

Wildlife diseases are a recognized driver of global biodiversity loss, have substantial economic impacts, and are increasingly becoming a threat to human health. Disease surveillance is critical but remains difficult in the wild due to the substantial costs and potential biases associated with most disease detection methods. Noninvasive scat surveys have been proposed as a health monitoring methodology to overcome some of these limitations. Here, we use the known threat of Chlamydia disease to the iconic, yet vulnerable, koala Phascolarctos cinereus to compare three methods for Chlamydia detection in scats: multiplex quantitative PCR, next generation sequencing, and a detection dog specifically trained on scats from Chlamydia‐infected koalas. All three methods demonstrated 100% specificity, while sensitivity was variable. Of particular interest is the variable sensitivity of these diagnostic tests to detect sick individuals (i.e., not only infection as confirmed by Chlamydia‐positive swabs, but with observable clinical signs of the disease); for koalas with urogenital tract disease signs, sensitivity was 78% with quantitative PCR, 50% with next generation genotyping and 100% with the detection dog method. This may be due to molecular methods having to rely on high‐quality DNA whereas the dog most likely detects volatile organic compounds. The most appropriate diagnostic test will vary with disease prevalence and the specific aims of disease surveillance. Acknowledging that detection dogs might not be easily accessible to all, the future development of affordable and portable "artificial noses" to detect diseases from scats in the field might enable cost‐effective, rapid and large‐scale disease surveillance. [ABSTRACT FROM AUTHOR]

Abstract: The use of biologging devices continues to increase with technological advances yielding remarkable ecological insights and generating new research questions. However, as devices develop and are deployed more widely, there is a need to update our knowledge of the potential ethical impacts to allow scientists to balance these against the knowledge gained. We employed a suite of phylogenetically controlled meta‐analyses on a dataset comprising more than 450 published effect sizes across 214 different studies to examine the effects of biologger tagging on five key traits in birds. Overall, we found small but significant negative effects of tagging on survival, reproduction, parental care. In addition, tagging was positively associated with foraging trip duration, but had no effect on body mass. Meta‐regressions revealed that flying style, migration distance and proportional tag mass were significant influences producing these deleterious effects, with attachment type and position additionally important covariates influencing survival‐ and reproduction‐based effect sizes. There was a positive correlation between the effects of tagging on survival and reproduction, highlighting that effects may be cumulative, with the full effects of tagging not necessarily apparent in studies focused on single traits. We discuss the tradeoff between these negative effects and the advances gained through the use of biologgers. Finally, given the number of studies from our initial literature search that lacked sufficient data for inclusion in analyses, we provide recommendations on the essential information that all biologging studies should report in order to facilitate future assessments of impacts on animals. [ABSTRACT FROM AUTHOR]

Maintaining genetic diversity is a crucial component in conserving threatened species. For the iconic Australian koala, there is little genetic information on wild populations that is not either skewed by biased sampling methods (e.g., sampling effort skewed toward urban areas) or of limited usefulness due to low numbers of microsatellites used. The ability to genotype DNA extracted from koala scats using next-generation sequencing technology will not only help resolve location sample bias but also improve the accuracy and scope of genetic analyses (e.g., neutral vs. adaptive genetic diversity, inbreeding, and effective population size). Here, we present the successful SNP genotyping (1272 SNP loci) of koala DNA extracted from scat, using a proprietary DArTseq™ protocol. We compare genotype results from two-day-old scat DNA and 14-day-old scat DNA to a blood DNA template, to test accuracy of scat genotyping. We find that DNA from fresher scat results in fewer loci with missing information than DNA from older scat; however, 14-day-old scat can still provide useful genetic information, depending on the research question. We also find that a subset of 209 conserved loci can accurately identify individual koalas, even from older scat samples. In addition, we find that DNA sequences identified from scat samples through the DArTseq™ process can provide genetic identification of koala diet species, bacterial and viral pathogens, and parasitic organisms. [ABSTRACT FROM AUTHOR]

The one-step synthesis of the first homoleptic II- tpy> metallomacrocycle is reported. Characterization of the OsII complex, along with its FeII and RuII analogues, was accomplished by NMR spectroscopy, ESI-MS, TWIM-MS, gradient tandem-MS, CV, luminescence and UV/Vis spectroscopy. Center-of-mass collision energies, derived from gradient tandem-MS, reveal that the II-tpy>-based structures are more stable than those of II-tpy>. [ABSTRACT FROM AUTHOR]

Wo ein Rad ist, ist auch ein Weg: Das auf Terpyridin basierende Titelsystem wurde in einem einfachen Selbstorganisationsprozess erhalten. Zwei Tris(terpyridin) ‐ Liganden mit Winkeln von 120 oder 60° zwischen benachbarten tpy ‐ Einheiten wurden mit einer stöchiometrischen Menge an Zn2+ (2:6:12) gemischt, was zur gewünschten koordinationsgetriebenen Fahrrad ‐ artigen Rad führte (90 % Ausbeute). [ABSTRACT FROM AUTHOR]

We report the self-assembly and isolation of two metallamacromolecular constitutional isomeric pairs based on connectivity. Utilizing a robust dimer with varying substitution to the core benzene ring resulted not only in the isolation of the expected 60°-oriented tetramer and 120°-oriented hexamer but also in the unexpected isolation of a 60°-oriented hexamer and a 120°-oriented tetramer. These isomers were characterized by 1H NMR spectroscopy and mass spectrometry (ESI-travelling wave ion mobility), which revealed significant structural differences. Molecular modeling was utilized to aid in characterization. [ABSTRACT FROM AUTHOR]