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Fossiliferous sediments of the Hadar Formation (Afar, Ethiopia) are preserved in the Hadar, Dikika, Gona, and Ledi-Geraru research areas, and have produced the most informative record of the mid-Pliocene hominin Australopithecus afarensis. Hundreds of specimens of A. afarensis have been recovered from the Hadar site, including a partial skeleton (A.L. 288–1), two nearly complete adult skulls (A.L. 444–2; A.L. 822–1), and a dense accumulation of hominin individuals of various ages (A.L. 333; Johanson et al., 1978b; Kimbel et al., 1994; Kimbel and Delezene, 2009). Across the Awash River at Dikika, a juvenile hominin skeleton (DIK-1–1) was recovered and possible evidence of hominin carnivory ~3.4 Ma based on cut-marked bone was reported from Hadar Formation sediments (Alemseged et al., 2006; McPherron et al., 2010; Thompson et al., 2015). Thus, the outcrops of the Hadar Formation, particularly those at Hadar, have been tremendously important in interpreting Pliocene hominin evolution in eastern Africa.
Public representations of long-term residential care (LTRC) facilities have received limited focus in Canada, although literature from other countries indicates that public perceptions of LTRC tend to be negative, particularly in contexts that prioritize aging and dying in place. Using Manitoba as the study context, we investigate a question of broad relevance to the Canadian perspective; specifically, what are current public perceptions of the role and function of long-term care in the context of a changing health care system? Through critical discourse analysis, we identify four overarching discourses dominating public perceptions of LTRC: the problem of public aging, LTRC as an imperfect solution to the problem, LTRC as ambiguous social spaces, and LTRC as a last resort option. Building on prior theoretical work, we suggest that public perceptions of LTRC are informed by neoliberal discourses that privilege individual responsibility and problematize public care.
King George Island (South Shetland Islands, Antarctic Peninsula) is renowned for its terrestrial palaeoenvironmental record, which includes evidence for potentially up to four Cenozoic glacial periods. An advantage of the glacigenic outcrops on the island is that they are associated with volcanic formations that can be isotopically dated. As a result of a new mapping and chronological study, it can now be shown that the published stratigraphy and ages of many geological units on eastern King George Island require major revision. The Polonez Glaciation is dated as c. 26.64 ± 1.43 Ma (Late Oligocene (Chattian Stage)) and includes the outcrops previously considered as evidence for an Eocene glacial ('Krakow Glaciation'). It was succeeded by two important volcanic episodes (Boy Point and Cinder Spur formations) formed during a relatively brief interval (< 2 Ma), which also erupted within the Oligocene Chattian Stage. The Melville Glaciation is dated as c. 21–22 Ma (probably 21.8 Ma; Early Miocene (Aquitanian Stage)), and the Legru Glaciation is probably ≤ c. 10 Ma (Late Miocene or younger). As a result of this study, the Polonez and Melville glaciations can now be correlated with increased confidence with the Oi2b and Mi1a isotope zones, respectively, and thus represent major glacial episodes.
Surface energy-balance models are commonly used in conjunction with satellite thermal imagery to estimate supraglacial debris thickness. Removing the need for local meteorological data in the debris thickness estimation workflow could improve the versatility and spatiotemporal application of debris thickness estimation. We evaluate the use of regional reanalysis data to derive debris thickness for two mountain glaciers using a surface energy-balance model. Results forced using ERA-5 agree with AWS-derived estimates to within 0.01 ± 0.05 m for Miage Glacier, Italy, and 0.01 ± 0.02 m for Khumbu Glacier, Nepal. ERA-5 data were then used to estimate spatiotemporal changes in debris thickness over a ~20-year period for Miage Glacier, Khumbu Glacier and Haut Glacier d'Arolla, Switzerland. We observe significant increases in debris thickness at the terminus for Haut Glacier d'Arolla and at the margins of the expanding debris cover at all glaciers. While simulated debris thickness was underestimated compared to point measurements in areas of thick debris, our approach can reconstruct glacier-scale debris thickness distribution and its temporal evolution over multiple decades. We find significant changes in debris thickness over areas of thin debris, areas susceptible to high ablation rates, where current knowledge of debris evolution is limited.
A growing body of literature proposes that our ancestors contributed to large mammal extinctions in Africa long before the appearance of Homo sapiens, with some arguing that premodern hominins (e.g., Homo erectus) triggered the demise of Africa's largest herbivores and the loss of carnivoran diversity. Though such arguments have been around for decades, they are now increasingly accepted by those concerned with biodiversity decline in the present-day, despite the near complete absence of critical discussion or debate. To facilitate that process, here we review ancient anthropogenic extinction hypotheses and critically examine the data underpinning them. Broadly speaking, we show that arguments made in favor of ancient anthropogenic extinctions are based on problematic data analysis and interpretation, and are substantially weakened when extinctions are considered in the context of long-term evolutionary, ecological, and environmental changes. Thus, at present, there is no compelling empirical evidence supporting a deep history of hominin impacts on Africa's faunal diversity.
The coronavirus disease 2019 pandemic has led to unprecedented disruption to the normal way of life for people around the globe. Social distancing, self-isolation or shielding have been strongly advised or mandated in most countries. We suggest evidence-based ways that people can maintain or even strengthen their mental health during this crisis.
Sexual dimorphism is common in many extant animals, but it is difficult to demonstrate in fossil species. Working with material from the Late Cretaceous of the U.S. Coastal Plain, we herein analyze sexual dimorphism in ostracodes from the superfamily Cytheroidea, a group whose extant members have males that are relatively more elongate than females. We digitized outlines of more than 6000 individual ostracode valves or carapaces, extracted size (area) and shape (length-to-height ratio) information, and used finite mixture models to assess hypotheses of sexual dimorphism. Male and female clusters can be discerned in nearly all populations with sufficient data, resulting in estimates of size and shape dimorphism for 142 populations across 106 species; an additional nine samples are interpreted to consist only of females. Dimorphism patterns varied across taxa, especially for body size: males range from 30% larger to 20% smaller than females. Magnitudes of sexual dimorphism are generally stable within species across time and space; we can demonstrate substantial evolutionary changes in dimorphism in only one species, Haplocytheridea renfroensis. Several lines of evidence indicate that patterns of sexual dimorphism in these ostracodes reflect male investment in reproduction, suggesting that this study system has the potential to capture variation in sexual selection through the fossil record.
Depression is common and an important consequence of stroke but there is limited information on the longer-term relationship between these conditions.
To identify the prevalence, incidence and predictors of depression in a secondary-care-based cohort of stroke survivors aged over 75 years, from 3 months to up to 10 years post-stroke.
Depression was assessed annually by three methods: major depression by DSM-IV criteria, the self-rated Geriatric Depression Scale (GDS) and the observer-rated Cornell scale.
We found the highest rates, 31.7% baseline prevalence, of depressive symptoms with the GDS compared with 9.7% using the Cornell scale and 1.2% using DSM-IV criteria. Incidence rates were 36.9, 5.90 and 4.18 episodes per 100 person years respectively. Baseline GDS score was the most consistent predictor of depressive symptoms at all time points in both univariate and multivariate analyses. Other predictors included cognitive impairment, impaired activities of daily living and in the early period, vascular risk factor burden and dementia.
Our results emphasise the importance of psychiatric follow-up for those with early-onset post-stroke depression and long-term monitoring of mood in people who have had a stroke and remain at high risk of depression.
This qualitative study aimed to gain insight into the experience of hospitalisation from the perspectives of the older person with dementia, their family care-giver and other patients sharing the ward (co-patients). Non-participant observation of care on 11 acute hospital wards was supplemented by 39 semi-structured interviews with 35 family care-givers and four co-patients following discharge. Constant comparative analysis produced the core problem facing all those involved: disruption from normal routine meaning that the experience of hospitalisation was disrupted by the presence and behaviour of the person with dementia. Disruption adversely affected the person with dementia, triggering constructive, disengaged, distressed and neutral behaviours. Using Kitwood's model of person-centred care, these behaviours were interpreted as attempts by the person with dementia at gaining a sense of control over the unfamiliar environment and experience. Family care-givers' lives and experiences both inside and outside the hospital were disrupted by the hospitalisation. They too attempted to gain a sense of control over the experience and to give a sense of control to the patient, co-patients and staff. Co-patients experienced disruption from sharing space with the person with dementia and were left feeling vulnerable and sometimes afraid. They too attempted to gain a sense of control over their situation and give some control by helping the person with dementia, the family care-giver and the staff.
This chapter argues that one of the main advantages of the dialogical self approach in psychotherapy is that it offers, in the concept of I-positions, a more effective way of approaching the multiplicity within the person. The I-positions offer a way of talking which neatly sidesteps the problem of reification inherent in such older concepts as subpersonalities, and ego states and parts. The main advantage of I-positions is that there is no suggestion with them of subordination, of their being lesser in some way than the whole person. The transpersonal is a vast realm for psychotherapy, counselling and coaching, and it has been emerging as a really important aspect of the therapeutic engagement over the past 30-odd years. The chapter illustrates the point that dialogical work can lead us into some very deep areas, and may suggest ways of working which are theoretically quite unusual.
The coastal alluvial fan sequences of Cyrenaica are important archives of environmental change data, but hitherto relatively little has been known about their formative processes and rates. The Wadi Zewana coastal fan near Tolmeita was studied and a range of dating techniques (U-Th, ESR and OSL) applied to selected components of the stratigraphy. The sequence spans the last two global glacial periods separated by an Interglacial. Cemented alluvial fan gravel units yielded U-Th leachate-residue ages of 201 ± 18 ka, 179 ± 15 ka and 138 ± 8 ka respectively. The fan toe units are interdigitated with bioclastic beach rock deposits dated to 150 ± 10.9 ka corresponding to an Interglacial high stand in sea level and marine recession sequence featuring transgressive lag gravels, beach sand and cemented aeolian dunes dated to 121 ± 8 ka. Within the Wadi Zewana catchment a complex cut and fill history is evidenced. Aggradation phases dated to 76 ± 4 ka, 42.1 ± 5.1 ka and 12.5 ± 1.5 ka are broadly coincident with global glacials and stadials, whilst during the Last Interglacial and successive interstadials the drainage system underwent entrenchment, manifested on the coastal plain as telescopic fan segmentation and associated fan head trenching.
Many small mammals inhabiting vegetation habitats where food resources are scattered have large home ranges with limited overlap. One way that they may effectively defend large territories is to establish dominance over the limited number of sites that provide good protection from predators, since displacement from these sites could have a very high cost to intruders. To examine this hypothesis we studied the fine-scale use of habitat and spatial dispersion of all adult male Mus spretus inhabiting a 1.1 ha grassland study site near Lisbon, Portugal, by radio telemetry, at the start of the breeding season. The location of each of the 10 males was mapped every hour, 24 h/day for up to seven days. Microhabitat characteristics were compared between a random sample of points in the study site and those where mice were found. Individual ranges did not overlap, despite the close proximity of their borders and the occupation of almost all suitable habitat, suggesting that individual dispersion was strongly influenced by the presence of neighbours; mean range size was 343 ± 95 m2. Residents covered less than one-third of their total range over 24 h, though neighbours did not intrude despite the apparent opportunities. Each male territory overlapped the territory of at least two females. Mice were neither nocturnal nor crepuscular, moving around mostly during the morning and evening. They avoided open woodland or pathways, preferring grassland sites with tall vegetation and sites where shrubs, bramble, or dead wood provided additional cover. Most fixes per male (70%) were located in one to four core areas, which represented only a tiny proportion of each range (6.9 ± 0.9%). Although exclusive defence of large complex ranges is likely to be impracticable, defence of core areas seems much more feasible. Our results thus support our hypothesis that mice may be able to maintain large exclusive ranges due to a combination of high predation pressure and a limited number of sites with sufficient ground and overhead cover. This will result in a very high risk to mice entering areas where competitors have priority of access to protected sites.