Lions and brown bears colonized North America in multiple synchronous waves of dispersal across the Bering Land Bridge.

The Bering Land Bridge connecting North America and Eurasia was periodically exposed and inundated by oscillating sea levels during the Pleistocene glacial cycles. This land connection allowed the intermittent dispersal of animals, including humans, between Western Beringia (far northeast Asia) and Eastern Beringia (northwest North America), changing the faunal community composition of both continents. The Pleistocene glacial cycles also had profound impacts on temperature, precipitation and vegetation, impacting faunal community structure and demography. While these palaeoenvironmental impacts have been studied in many large herbivores from Beringia (e.g., bison, mammoths, horses), the Pleistocene population dynamics of the diverse guild of carnivorans present in the region are less well understood, due to their lower abundances. In this study, we analyse mitochondrial genome data from ancient brown bears (Ursus arctos; n = 103) and lions (Panthera spp.; n = 39), two megafaunal carnivorans that dispersed into North America during the Pleistocene. Our results reveal striking synchronicity in the population dynamics of Beringian lions and brown bears, with multiple waves of dispersal across the Bering Land Bridge coinciding with glacial periods of low sea levels, as well as synchronous local extinctions in Eastern Beringia during Marine Isotope Stage 3. The evolutionary histories of these two taxa underline the crucial biogeographical role of the Bering Land Bridge in the distribution, turnover and maintenance of megafaunal populations in North America.

Health status and healthcare trends of individuals accessing Australian aged care programmes over a decade: the Registry of Senior Australians historical cohort.

BACKGROUND: Understanding the health profile, service and medicine use of Australians in the aged care sector will help inform appropriate service provision for our ageing population. AIMS: To examine the 2006-2015 trends in (i) comorbidities and frailty of individuals accessing aged care, and (ii) health services, medicine use and mortality after entry into long-term care. METHODS: Cross-sectional and population-based trend analyses were conducted using the Registry of Senior Australians. RESULTS: From 2006 to 2015, 509 944 individuals accessed permanent residential care, 206 394 home care, 283 014 respite and 124 943 transition care. Over this time, the proportion of individuals accessing permanent residential care with high frailty scores (≥0.3) increased (19.7-49.7%), as did the proportion with 5-9 comorbidities (46.4-54.5%), with similar trends observed for those accessing other services. The median number of medicines dispensed in the year after entering permanent residential care increased from 9 (interquartile range (IQR) 6-12) to 10 (IQR 7-14), while remaining stable in home care (2006: 9, IQR 5-12, 2015: 9, IQR 6-13). Short-term (within 100 days) mortality in those accessing permanent care was higher in 2006 (15.6%, 95% CI 15.2-16.0) than 2015 (14.6%, 95% CI 14.3-14.9). Longer term (101-1095 days, 2006: 44.3%, 95% CI 43.7-45.0, 2015: 46.4%, 95% CI 45.8-46.9) mortality was higher in 2015 compared to 2006. Mortality in individuals accessing home care did not change. CONCLUSION: The health of older Australians accessing aged care programmes has declined while frailty increased, with an increasing use of medicine and worse long-term mortality in some. Funding and care models need to adapt to this changing profile.

The Registry of Senior Australians outcome monitoring system: quality and safety indicators for residential aged care.

OBJECTIVES: To introduce the Registry of Senior Australians (ROSA) Outcome Monitoring System, which can monitor the quality and safety of care provided to individuals accessing residential aged care. Development and examination of 12 quality and safety indicators of care and their 2016 prevalence estimates are presented. DESIGN: Retrospective. SETTING: 2690 national and 254 South Australian (SA) aged care facilities. PARTICIPANTS: 208 355 unique residents nationally and 18 956 in SA. MAIN OUTCOME MEASURES: Risk-adjusted prevalence of high sedative load, antipsychotic use, chronic opioid use, antibiotic use, premature mortality, falls, fractures, medication-related adverse events, weight loss/malnutrition, delirium and/or dementia hospitalisations, emergency department presentations, and pressure injuries. RESULTS: Five indicators were estimated nationally; antibiotic use (67.5%, 95% confidence interval (CI): 67.3-67.7%) had the highest prevalence, followed by high sedative load (48.1%, 95% CI: 47.9-48.3%), chronic opioid use (26.8%, 95% CI: 26.6-26.9%), antipsychotic use (23.5%, 95% CI: 23.4-23.7%) and premature mortality (0.6%, 95% CI: 0.6-0.7%). Seven indicators were estimated in SA; emergency department presentations (19.1%, 95% CI: 18.3-20.0%) had the highest prevalence, followed by falls (10.1%, 95% CI: 9.7-10.4%), fractures (4.8%, 95% CI: 4.6-5.1%), pressure injuries (2.9%, 95% CI: 2.7-3.1%), delirium and/or dementia related hospitalisations (2.3%, 95% CI: 2.1-2.6%), weight loss/malnutrition (0.7%, 95% CI: 0.6-0.8%) and medication-related events (0.6%, 95% CI: 0.5-0.7%). CONCLUSIONS: Twelve quality and safety indicators were developed to monitor aged care provided to older Australians based on the synthesis of existing literature and expert advisory input. These indicators rely on existing data within the aged care and healthcare sectors, therefore creating a pragmatic tool to examine quality and unwarranted care variation.

Factors associated with accessing aged care services in Australia after approval for services: Findings from the historical cohort of the Registry of Senior Australians.

OBJECTIVE: To evaluate the access of approved aged care services and factors associated with accessing these services. METHODS: A retrospective cohort study was conducted (1/7/2003-30/6/2013). The incidence of accessing permanent residential, home and respite care services within one year or transition care within 28 days of approval was evaluated. The association of participants' socio-demographic characteristics, limitations, health conditions and assessment characteristics with service use was evaluated. RESULTS: In 799 750 older Australians, the incidence of accessing approved permanent residential care within one year was 70.9% (95% confidence interval [CI] 70.8%-71.0%), home care 49.5% (95% CI 49.3%-49.7%) and respite 41.8% (95% CI 41.7%-41.9%). The incidence of accessing transition care at 28 days was 78.5% (95% CI 78.2%-78.7%). Aged care seekers', assessments' and assessors' characteristics are associated with service access. CONCLUSION: Monitoring the use of aged care service approvals is necessary for the identification of service access barriers to support evidence-based policy changes.

Synergistic roles of climate warming and human occupation in Patagonian megafaunal extinctions during the Last Deglaciation.

The causes of Late Pleistocene megafaunal extinctions (60,000 to 11,650 years ago, hereafter 60 to 11.65 ka) remain contentious, with major phases coinciding with both human arrival and climate change around the world. The Americas provide a unique opportunity to disentangle these factors as human colonization took place over a narrow time frame (~15 to 14.6 ka) but during contrasting temperature trends across each continent. Unfortunately, limited data sets in South America have so far precluded detailed comparison. We analyze genetic and radiocarbon data from 89 and 71 Patagonian megafaunal bones, respectively, more than doubling the high-quality Pleistocene megafaunal radiocarbon data sets from the region. We identify a narrow megafaunal extinction phase 12,280 ± 110 years ago, some 1 to 3 thousand years after initial human presence in the area. Although humans arrived immediately prior to a cold phase, the Antarctic Cold Reversal stadial, megafaunal extinctions did not occur until the stadial finished and the subsequent warming phase commenced some 1 to 3 thousand years later. The increased resolution provided by the Patagonian material reveals that the sequence of climate and extinction events in North and South America were temporally inverted, but in both cases, megafaunal extinctions did not occur until human presence and climate warming coincided. Overall, metapopulation processes involving subpopulation connectivity on a continental scale appear to have been critical for megafaunal species survival of both climate change and human impacts.

Ancient mitochondrial DNA reveals convergent evolution of giant short-faced bears (Tremarctinae) in North and South America.

The Tremarctinae are a subfamily of bears endemic to the New World, including two of the largest terrestrial mammalian carnivores that have ever lived: the giant, short-faced bears Arctodus simus from North America and Arctotherium angustidens from South America (greater than or equal to 1000 kg). Arctotherium angustidens became extinct during the Early Pleistocene, whereas Arctodus simus went extinct at the very end of the Pleistocene. The only living tremarctine is the spectacled bear (Tremarctos ornatus), a largely herbivorous bear that is today only found in South America. The relationships among the spectacled bears (Tremarctos), South American short-faced bears (Arctotherium) and North American short-faced bears (Arctodus) remain uncertain. In this study, we sequenced a mitochondrial genome from an Arctotherium femur preserved in a Chilean cave. Our molecular phylogenetic analyses revealed that the South American short-faced bears were more closely related to the extant South American spectacled bear than to the North American short-faced bears. This result suggests striking convergent evolution of giant forms in the two groups of short-faced bears (Arctodus and Arctotherium), potentially as an adaptation to dominate competition for megafaunal carcasses.

Mitochondrial genomes reveal an explosive radiation of extinct and extant bears near the Miocene-Pliocene boundary.

BACKGROUND: Despite being one of the most studied families within the Carnivora, the phylogenetic relationships among the members of the bear family (Ursidae) have long remained unclear. Widely divergent topologies have been suggested based on various data sets and methods. RESULTS: We present a fully resolved phylogeny for ursids based on ten complete mitochondrial genome sequences from all eight living and two recently extinct bear species, the European cave bear (Ursus spelaeus) and the American giant short-faced bear (Arctodus simus). The mitogenomic data yield a well-resolved topology for ursids, with the sloth bear at the basal position within the genus Ursus. The sun bear is the sister taxon to both the American and Asian black bears, and this clade is the sister clade of cave bear, brown bear and polar bear confirming a recent study on bear mitochondrial genomes. CONCLUSION: Sequences from extinct bears represent the third and fourth Pleistocene species for which complete mitochondrial genomes have been sequenced. Moreover, the cave bear specimen demonstrates that mitogenomic studies can be applied to Pleistocene fossils that have not been preserved in permafrost, and therefore have a broad application within ancient DNA research. Molecular dating of the mtDNA divergence times suggests a rapid radiation of bears in both the Old and New Worlds around 5 million years ago, at the Miocene-Pliocene boundary. This coincides with major global changes, such as the Messinian crisis and the first opening of the Bering Strait, and suggests a global influence of such events on species radiations.