Fun in facets: A flexible new tool for population genomics in R.

The landscape of analytical tools for population genomics continues to evolve. However, these tools are scattered across programming languages, making them largely inaccessible for many biologists. In this issue of Molecular Ecology Resources, Hemstrom and Jones, 2022 (Mol Ecol Resour; 962) introduce a new R package, snpR. This package combines a large number of existing analyses, to provide a one-stop shop for population genomics. F-statistics, admixture analyses, effective population size inferences, genome-wide association studies (GWAS), and parentage analyses are all implemented natively within the package. A variety of third-party software can also be run without leaving the R environment. The authors pay particular attention to data structure - avoiding redundancy - and allowing analyses to be run across multiple sample or single-nucleotide polymorphism (SNP) groupings. Because of its great accessibility and wide range of analyses, snpR has the potential to become a favourite within the Molecular Ecology community.

Dispersal Reduction: Causes, Genomic Mechanisms, and Evolutionary Consequences.

Recent biological analyses suggest that reductions in dispersal ability have been key drivers of diversification across numerous lineages. We synthesise emerging data to highlight similarities regarding the causes and consequences of dispersal reduction across taxa and ecosystems, as well as the diverse genomic mechanisms underpinning these shifts. Natural selection has acted on standing genetic variation within taxa to drive often rapid - and in some cases parallel - losses of dispersal, and ultimately speciation. Such shifts can thus represent an important nexus between adaptive and neutral diversification processes, with substantial evolutionary consequences. Recognition of the links between these concepts that are emerging from different fields, taxa and ecosystems is transforming our understanding of the fascinating role of dispersal reduction in the formation of biodiversity.

Deaths in Incorrectly Identified Low-Surgical-Risk Patients.

BACKGROUND: The American Society of Anesthesiologists (ASA) physical classification system was developed for assessing anaesthetic risk, but is often also used to estimate surgical death risk. Patients with low ASA grades (ASA 1 or 2) are expected to have better surgical outcomes than patients with higher ASA grades (ASA ≥ 4). This study examined the course to death in patients classified as ASA 1 or 2 was examined, to investigate possible factors in unexpected deaths, in addition to evaluating the use of ASA grades by clinicians. METHODS: Patient data from the national surgical mortality audit of Australian hospitals were examined. The patient group was listed as ASA grade 1 or 2 by surgeons. Patients over 60 or under 20 were excluded in the final analysis, as were cases from New South Wales due to data not being available. A total of 357 cases were examined. Assessor summaries of the cases were examined, and ASA score reassessed to determine accuracy. RESULTS: More than 95% (n = 339) of cases listed as ASA 1 or 2 were found to have an incorrectly low grade, with 17.6% (n = 63) of cases listed as "expected" deaths. CONCLUSION: ASA grades appear to be misunderstood in the reporting of patient surgical risk. Many patient summaries list patients with severe systemic disease or expected deaths as ASA 1 or 2, contrary to the intended use of this classification system. Improved education on the use of the ASA grading system would be beneficial to clinicians.

Flight of Rhyzopertha dominica (Coleoptera: Bostrichidae)-a Spatio-Temporal Analysis With Pheromone Trapping and Population Genetics.

The flight of the lesser grain borer, Rhyzopertha dominica (F.), near grain storages and at distances from them, was investigated to assess the potential of these beetles to infest grain and spread insecticide resistance genes. We caught R. dominica in pheromone-baited flight traps (and blank controls) set at storages, in fields away from storages, and in native vegetation across a 12-mo period. A functional set of highly polymorphic microsatellite markers was developed, enabling population genetic analyses on the trapped beetles. Pheromone-baited traps caught just as many R. dominica adults at least 1 km from grain storages as were caught adjacent to grain storages. Samples of beetles caught were genetically homogeneous across the study area (over 7,000 km2) in South Queensland, Australia. However, a change in genetic structure was detected at one bulk storage site. Subsequent analysis detected a heterozygous excess, which indicated a population bottleneck. Only a few beetles were caught during the winter months of June and July. To assess the mating status and potential fecundity of dispersing R. dominica females, we captured beetles as they left grain storages and quantified offspring production and life span in the laboratory. Nearly all (95%) of these dispersing females had mated and these produced an average of 242 offspring. We demonstrated that R. dominica populations in the study area display a high degree of connectivity and this is a result of the active dispersal of mated individuals of high potential fecundity.

Phrenic nerve pacing in two young quadriplegic ventilator-dependent patients.

Patients who survive high cervical injury are usually dependent on mechanical ventilation and tracheostomy if the lesion above C3 is complete. We report our experience with phrenic nerve pacing (PNP) to achieve ventilator-independence in two young quadriplegic patients. A diaphragm conditioning programme, and combination of low frequency electrophrenic stimulation within each inspiratory burst and low breathing frequency enabled both patients initially to achieve continuous 24 hour ventilation independent of mechanical ventilation. One patient reverted to overnight mechanical ventilation (six hours) after three years. PNP should be considered in ventilator dependent patients with high cervical injury to achieve independence and improve quality of life.

Posterior fossa extradural haematoma.

A case of extradural haematoma of the posterior cranial fossa is presented and some of the pertinent literature reviewed. Suggestions are made which may enable the general surgeon and his staff looking after the patient in the acute phase to detect the presence of this lesion.