Ages-at-death distribution of the early Pleistocene hominin fossil assemblage from Drimolen (South Africa).

OBJECTIVES: A prevailing hypothesis in paleoanthropology is that early Pleistocene hominin bones were accumulated in South African caves by carnivores, which used those shelters, and the trees surrounding them, as refuge and feeding sites. We tested this hypothesis at the site of Drimolen, by comparing its hominin age-at-death distribution to that of the nearby and roughly contemporaneous site of Swartkrans. MATERIALS AND METHODS: We employed standard dental aging systems in order to categorize the Drimolen hominin teeth into age classes of 5 years each. We then compared the age-at-death distribution for Drimolen with the published data available for the Swartkrans hominins. RESULTS: Age-at-death distributions indicate that the age category "young adults" is the best represented age category at Swartkrans and the most poorly represented one at Drimolen. Moreover, Drimolen has a preponderance of infant specimens. Both sites have a low frequency of old adult specimens. CONCLUSIONS: Differences observed in frequencies of the age-at-death categories suggest different mechanisms of hominin skeletal accumulation at Drimolen and Swartkrans. Swartkrans' frequency curve reflects mortality in a population subjected to predation and is thus consistent with the carnivore-accumulating hypothesis. In contrast, the Drimolen curve is similar to that of wild populations of living apes. Living primates have been observed exploiting caves as sleeping shelters, for nutritional, security, drinking, and thermoregulatory purposes. We suggest that similar cave use by Pleistocene hominins can explain, in large part, the accumulation of hominin bones at Drimolen. Such a conclusion is another illustration of the growing awareness that a "one-size-fits-all" taphonomic model for South African early Pleistocene hominin sites is probably insufficient.

On the measurement of cause of death inequality.

BACKGROUND: Attempts at assessing heterogeneity in countries' mortality profiles often rely on measures of cause of death (CoD) diversity. Unfortunately, such indicators fail to take into consideration the degree of (dis)similarity among pairs of causes (e.g. 'transport injuries' and 'unintentional injuries' are implicitly assumed to be as dissimilar as 'transport injuries' and 'Alzheimer's disease')－an unrealistic and unduly restrictive assumption. DEVELOPMENT: We extend diversity indicators proposing a broader class of heterogeneity measures that are sensitive to the similarity between the causes of death one works with. The so-called 'CoD inequality' measures are defined as the average expected 'dissimilarity between any two causes of death'. A strength of the approach is that such measures are decomposable, so that users can assess the contribution of each cause to overall CoD heterogeneity levels-a useful property for the evaluation of public health policies. APPLICATION: We have applied the method to 15 low-mortality countries between 1990 and 2019, using data from the Global Burden of Disease project. CoD inequality and CoD diversity generally increase over time across countries and sex, but with some exceptions. In several cases (notably, Finland), both indicators run in opposite directions. CONCLUSIONS: CoD inequality and diversity indicators capture complementary information about the heterogeneity of mortality profiles, so they should be analysed alongside other population health metrics, such as life expectancy and lifespan inequality.

Judging a reindeer by its teeth: A user-friendly tooth wear and eruption pattern recording scheme to estimate age-at-death in reindeer (Rangifer tarandus).

Reindeer (Rangifer tarandus) have shaped the cultures and provided livelihood to peoples of the Northern Hemisphere for thousands of years. They are still the socio-economic cornerstone of many northern cultures. Insight into reindeer mortality patterns is important for understanding past human-reindeer interactions and reindeer population fluctuations in relation to climatic and environmental change. Beyond archaeology, assessing the age structures of modern reindeer populations is important for developing wildlife management strategies. This paper presents a quick, non-destructive and cheap method to estimate age in reindeer in both modern and ancient populations based on tooth wear and eruption patterns of mandibular teeth. We devised the method using a large sample of Svalbard reindeer (Rangifer tarandus platyrhynchus) of known age. We blind-tested the method and tested its applicability on another known-age Svalbard reindeer mandible assemblage. The tests demonstrate our methods' user-friendliness and reliability to generate reproducible, reusable datasets and accuracy in estimating reindeer age-at-death.

When children have children: The effects of child marriages and teenage pregnancies on early childhood mortality in Bangladesh.

This paper examines the adverse effects of adolescent childbearing on early childhood mortality in Bangladesh in mother-fixed-effects regressions using individual mortality outcomes of 300,000 children. Children born to young mothers (child brides in Bangladesh) suffer from higher mortality in the first year of life than their siblings born later. The survival chances of children born to mothers aged 15-49 years are 48-81 % higher in infant period as compared to their siblings born in mother's early adolescence (10-14 years). In poor households, these survival effects extend up to the fifth birthday, especially in the poorest households or among uneducated mothers. This evidence points towards a biological channel, probably low birth weight, as the main contributing factor in the first year of life. In the post-infant period, favorable socio-economic factors (wealth, education) seem to compensate the biological disadvantage of adolescent births. Adolescent pregnancies lead annually to estimated 18,700 under-5 deaths in Bangladesh.

Last Breath in the Emergency Department.

BACKGROUND: Early and aggressive time to intervention has been shown to increase the odds of survival and decrease mortality in critically ill patients. Since emergency medicine is a nascent specialty in India, a review and assessment of the mortality profile in the Emergency Department (ED) would help improve the quality of care. AIMS: The aim of the study is to determine the mortality profile and causes of preventable deaths at large ED in South India. METHODS: This retrospective chart review was conducted between January and December 2017. Patients admitted with Triage priority 1 and priority 2 of our ED, who died, despite treatment, were recruited in the study. Two ED consultants blinded from each other, independently audited all the charts to determine preventable and nonpreventable causes of death. RESULTS: There were a total of 69,369 patients during the study period who presented to the ED. Despite resuscitation 189 (0.7%) died, the mortality rate was 2.43%. Cardiac-related (32%) and sepsis-related (31%) causes were the most common cause of death, 23.8% were due to preventable causes and 16.9% of which were due to inappropriate management. In patients with sepsis, the odds of death due to preventable causes were significantly high (odds ratio 4.31, 95% confidence intervals: 1.96-9.47; P < 0.001). CONCLUSIONS: Cardiac- and sepsis-related causes of death, together accounted for most of the mortality. In patients with sepsis, the odds of death due to preventable causes were more than four times higher than those without preventable causes.

Distinct mortality profile in systemic sclerosis: a death certificate study in Rio de Janeiro, Brazil (2006-2015) using a multiple causes of death analysis.

The objective of this study was to assess the mortality profile related to SSc in the state of Rio de Janeiro, Brazil. We retrospectively examined all registered deaths in the region (2006-2015 period) in which the diagnosis of SSc was mentioned on any line of the death certificates (underlying cause of death [UCD], n = 223; non-UCD, n = 151). Besides the analysis of gender, age, and the causes of death, we also compared the mortality from UCDs between individuals whose death causes included SSc (cases) and those whose death causes did not include SSc (deceased controls). For the latter comparison, we used the mortality odds ratio to approximate the cause-specific standardized mortality ratio. We identified 1495 death causes among the 374 SSc cases. The mean age at death of the SSc cases (85% women) was significantly lower than that of the controls (n = 1,294,117) (58.7 vs. 65.5 years, respectively). The main death causes were circulatory system diseases, infections, and respiratory diseases (36%, 34%, and 21% of SSc cases, respectively). Compared to the deceased controls, there were proportionally more deaths among the SSc cases from pulmonary arterial hypertension, lung fibrosis, septicemia, gastrointestinal hemorrhage, other systemic connective tissue diseases, and heart failure (for death age < 50 years). We confirmed the high burden of cardiovascular, respiratory, and infectious causes in this predominantly non-Caucasian sample of SSc patients. Of interest, the percentage of infection-related deaths in our report was about three times higher than that in SSc studies with predominantly Caucasian populations.