Early and Middle Holocene Hunter-Gatherer Occupations in Western Amazonia: The Hidden Shell Middens

We report on previously unknown early archaeological sites in the Bolivian lowlands, demonstrating for the first time early and middle Holocene human presence in western Amazonia. Multidisciplinary research in forest islands situated in seasonally-inundated savannahs has revealed stratified shell middens produced by human foragers as early as 10,000 years ago, making them the oldest archaeological sites in the region. The absence of stone resources and partial burial by recent alluvial sediments has meant that these kinds of deposits have, until now, remained unidentified. We conducted core sampling, archaeological excavations and an interdisciplinary study of the stratigraphy and recovered materials from three shell midden mounds. Based on multiple lines of evidence, including radiocarbon dating, sedimentary proxies (elements, steroids and black carbon), micromorphology and faunal analysis, we demonstrate the anthropogenic origin and antiquity of these sites. In a tropical and geomorphologically active landscape often considered challenging both for early human occupation and for the preservation of hunter-gatherer sites, the newly discovered shell middens provide evidence for early to middle Holocene occupation and illustrate the potential for identifying and interpreting early open-air archaeological sites in western Amazonia. The existence of early hunter-gatherer sites in the Bolivian lowlands sheds new light on the region's past and offers a new context within which the late Holocene "Earthmovers" of the Llanos de Moxos could have emerged. © 2013 Lombardo et al

Geomorphological and sedimentary evidence for late Pleistocene to Holocene hydrological change along the Río Mamoré, Bolivian Amazon

Aerial photography and satellite imagery reveal manifold geomorphological evidence of a dynamic evolution of past and present rivers in the Bolivian Amazon. Comparison of oxbow lake and meander scar dimensions along an inactive meander belt of the Río Mamoré (Llanos de Moxos, north-eastern Bolivia) and its modern counterpart suggests significant regional paleohydrological variability. We used these features as geomorphological and sedimentary archives to enhance our understanding of longer-term variations of the fluvial system. Late Pleistocene to Holocene hydrological changes of the Río Mamoré are inferred from: (i) the analysis of satellite imagery, (ii) discharge estimates from meander morphology, (iii) stratigraphic, and (iv) chronological information based on luminescence and radiocarbon dating. The combined data from three oxbows indicate that the now abandoned meander belt – the paleo-Mamoré – continued to be active at least until ∼5 ka, and likely even postdating 3 ka. An up to threefold increase in discharge is estimated for the modern Río Mamoré versus the paleo-Mamoré. The altered runoff regime may have triggered an avulsive shift towards the currently active Río Mamoré. The preceding increase in discharge in turn, was possibly related to a shift in climatic conditions, which changed markedly between the mid- and late Holocene in tropical South America. In addition, it may have been the indirect result of capturing the avulsive Río Grande system to the east of the Río Mamoré. Alternative explanations for the differences in dimensions of the paleo versus the modern Río Mamoré, i.e. contemporaneous activity of both rivers or alteration of site factors such as the channel/floodplain relationship, are considered to be unlikely

Differences in observed and self-reported compliance with ‘Five Moments for Hand Hygiene’ as a function of the empathy of healthcare workers

Background: Hand hygiene at critical time-points (as established by the World Health Organization's model 'Five Moments for Hand Hygiene') remains the leading measure for minimizing the risk of healthcare-associated infections. While many interventions have been tested to improve hand hygiene compliance (HHC) of healthcare workers (HCWs), little is known about the relationship between HHC and empathy of HCWs.Aim: To investigate the relationship between moment-specific HHC rates and empathy of HCWs at both individual and ward levels. Methods: HHC data were collected via observation and self-report, and empathy levels were measured using an established questionnaire. The survey was conducted on 38 wards of three tertiary care hospitals in Germany. Observation data were obtained via in-house observations conducted <8 months before or after the survey.Findings: Evidence for the expected correlation between empathy of HCWs and moment-specific HHC was found for both observed HHC (Moment 1: r=0.483, P=0.031; Moment 2: r=588, P=0.006) and self-reported HHC (Moment 1: r=0.093, P=0.092; Moment 2: r=0.145, P=0.008). In analyses of variance, the critical interaction effect between empathy (i.e. lower vs higher empathy) and designated time-point of hand hygiene (i.e. before vs after reference task) was also significant.Conclusion: Empathy of HCWs should be considered as an important factor in explaining differences between moment-specific HHC rates. In consequence, empathy comes into focus not only as a crucial factor for high-quality patient care, but also as an important contributor to improving HHC. 2022 The Authors. Published by Elsevier Ltd on behalf of The Healthcare Infection Society. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)