Adaptive foraging behaviours in the Horn of Africa during Toba supereruption.

Although modern humans left Africa multiple times over 100,000 years ago, those broadly ancestral to non-Africans dispersed less than 100,000 years ago1. Most models hold that these events occurred through green corridors created during humid periods because arid intervals constrained population movements2. Here we report an archaeological site-Shinfa-Metema 1, in the lowlands of northwest Ethiopia, with Youngest Toba Tuff cryptotephra dated to around 74,000 years ago-that provides early and rare evidence of intensive riverine-based foraging aided by the likely adoption of the bow and arrow. The diet included a wide range of terrestrial and aquatic animals. Stable oxygen isotopes from fossil mammal teeth and ostrich eggshell show that the site was occupied during a period of high seasonal aridity. The unusual abundance of fish suggests that capture occurred in the ever smaller and shallower waterholes of a seasonal river during a long dry season, revealing flexible adaptations to challenging climatic conditions during the Middle Stone Age. Adaptive foraging along dry-season waterholes would have transformed seasonal rivers into 'blue highway' corridors, potentially facilitating an out-of-Africa dispersal and suggesting that the event was not restricted to times of humid climates. The behavioural flexibility required to survive seasonally arid conditions in general, and the apparent short-term effects of the Toba supereruption in particular were probably key to the most recent dispersal and subsequent worldwide expansion of modern humans.

Description and Implications of Falls in Patients Hospitalized Due to COVID-19.

BACKGROUND: Many hospital quality indicators, including falls, worsened during the COVID-19 pandemic. Patients hospitalized with COVID-19 may be at risk for falling due to the disease itself, patient characteristics, or aspects of care delivery. PURPOSE: To describe and explore falls in patients hospitalized with COVID-19. METHODS: We pooled data from 107 hospitalized adult patients who fell between March 2020 and April 2021. Patients who fell had a current, pending, or recent diagnosis of COVID-19. We analyzed patient characteristics, fall circumstances, and patient and organizational contributing factors using frequencies, the chi-square test, and Fisher's exact test. RESULTS: Patient contributing factors included patients' lack of safety awareness, impaired physical function, and respiratory concerns. Organizational contributing factors related to staff and the isolation environment. CONCLUSIONS: Recommendations for managing fall risk in patients hospitalized with COVID-19 include frequent reassessment of risk, consideration of respiratory function as a risk factor, ongoing patient education, assisted mobility, and adequate staff training.

Vaccination with post-translational modified, homocitrullinated peptides induces CD8 T-cell responses that mediate antitumor immunity.

BACKGROUND: Post-translational modification of proteins has the potential to alter the ability of T cells to recognize major histocompatibility complex (MHC) class -I and class-II restricted antigens, thereby resulting in altered immune responses. One such modification is carbamylation (homocitrullination) that results in the formation of homocitrulline (Hcit) residues in a non-enzymatic reaction of cyanate with the lysine residues in the polypeptide chain. Homocitrullination occurs in the tumor microenvironment and CD4-mediated immune responses to Hcit epitopes can target stressed tumor cells and provide a potent antitumor response in mouse models. METHODS: Homocitrullinated peptides were identified and assessed in vitro for HLA-A2 binding and in vivo in human leukocyte antigen (HLA) transgenic mouse models for immunogenicity. CD8 responses were assessed in vitro for cytotoxicity and in vivo tumor therapy. Human tumor samples were analyzed by targeted mass spectrometry for presence of homocitrullinated peptides. RESULTS: Homocitrullinated peptides from aldolase and cytokeratin were identified, that stimulated CD8-mediated responses in vivo. Modified peptides showed enhanced binding to HLA-A2 compared with the native sequences and immunization of HLA-A2 transgenic mice generated high avidity modification specific CD8 responses that killed peptide expressing target cells. Importantly, in vivo the homocitrullinated aldolase specific response was associated with efficient CD8 dependent antitumor therapy of the aggressive murine B16 tumor model indicating that this epitope is naturally presented in the tumor. In addition, the homocitrullinated aldolase epitope was also detected in human tumor samples. CONCLUSION: This is the first evidence that homocitrullinated peptides can be processed and presented via MHC-I and targeted for tumor therapy. Thus, Hcit-specific CD8 T-cell responses have potential in the development of future anticancer therapy.

Citrullinated glucose-regulated protein 78 is a candidate target for melanoma immunotherapy.

Introduction: Post translational modification of proteins plays a significant role in immune recognition. In particular the modification of arginine to citrulline which is mediated by PAD enzymes is increased during cellular stress (autophagy) which permits the presentation of modified epitopes upon MHC class II molecules for recognition by CD4 T cells. Citrullination also occurs in tumour cells as a result of continuous environmental stresses and increased autophagy. We have shown in animal models the efficient stimulation of citrullinated epitope specific CD4 T cells resulting in dramatic elimination/regression of tumours. The ER chaperone glucose-regulated protein 78 (GRP78) is known to also be required for stress-induced autophagy and is directly linked to autophagosome formation. GRP78 is known to be highly expressed by many tumour types. In this study we investigate the potential of targeting citrullinated GRP78 for cancer therapy. Methods: A citrullinated GRP78 specific antibody was used to assess citrullinated GRP78 expression in murine and human tumour cells by flow cytometry. Five peptides were selected and used to vaccinate HLA transgenic mice and immune responses were characterised by ex vivo cytokine ELISpot assay. T cell repertoire in humans was assessed through proliferation assays and cytokine ELISpot assay. Citrullinated peptide was identified in murine B16 melanoma by mass spectrometry and the peptide vaccine was assessed for tumour therapy in a mouse melanoma model. Results: We show the identification CD4 T cell responses to one citrullinated GRP78 epitope that are restricted through HLA DP*0401 and HLA-DR*0101 alleles. This peptide is detected by mass spectrometry in B16 melanoma grown in vivo and citrulline specific CD4 responses to two peptides spanning this epitope mediate efficient therapy of established B16 melanoma tumours in HHDII/DP4 (p<0.0001) transgenic mouse model. Finally, we demonstrate the existence of a repertoire of responses to the citrullinated GRP78 peptide in healthy individuals (p=0.0023) with 13/17 (76%) individuals showing a response to this peptide. Conclusion: We propose that citrullinated GRP78 is a candidate tumour antigen and vaccination against citrullinated GRP78 may provide a promising tumour therapy approach.

Erratum: Bridging the gap between research, policy, and practice: Lessons learned from academic-public partnerships in the CTSA network - CORRIGENDUM.

[This corrects the article DOI: 10.1017/cts.2020.23.].

Bridging the gap between research, policy, and practice: Lessons learned from academic-public partnerships in the CTSA network.

A primary barrier to translation of clinical research discoveries into care delivery and population health is the lack of sustainable infrastructure bringing researchers, policymakers, practitioners, and communities together to reduce silos in knowledge and action. As National Institutes of Health's (NIH) mechanism to advance translational research, Clinical and Translational Science Award (CTSA) awardees are uniquely positioned to bridge this gap. Delivering on this promise requires sustained collaboration and alignment between research institutions and public health and healthcare programs and services. We describe the collaboration of seven CTSA hubs with city, county, and state healthcare and public health organizations striving to realize this vision together. Partnership representatives convened monthly to identify key components, common and unique themes, and barriers in academic-public collaborations. All partnerships aligned the activities of the CTSA programs with the needs of the city/county/state partners, by sharing resources, responding to real-time policy questions and training needs, promoting best practices, and advancing community-engaged research, and dissemination and implementation science to narrow the knowledge-to-practice gap. Barriers included competing priorities, differing timelines, bureaucratic hurdles, and unstable funding. Academic-public health/health system partnerships represent a unique and underutilized model with potential to enhance community and population health.

Patient and system factors associated with unassisted and injurious falls in hospitals: an observational study.

BACKGROUND: Unassisted falls are more likely to result in injury than assisted falls. However, little is known about risk factors for falling unassisted. Furthermore, rural hospitals, which care for a high proportion of older adults, are underrepresented in research on hospital falls. This study identified risk factors for unassisted and injurious falls in rural hospitals. METHODS: Seventeen hospitals reported 353 falls over 2 years. We categorized falls by type (assisted vs. unassisted) and outcome (injurious vs. non-injurious). We used multivariate logistic regression to determine factors that predicted fall type and outcome. RESULTS: With all other factors being equal, the odds of falling unassisted were 2.55 times greater for a patient aged ≥65 than < 65 (95% confidence interval [CI] = 1.30-5.03), 3.70 times greater for a patient with cognitive impairment than without (95% CI = 2.06-6.63), and 6.97 times greater if a gait belt was not identified as an intervention for a patient than if it was identified (95% CI = 3.75-12.94). With all other factors being equal, the odds of an injurious fall were 2.55 times greater for a patient aged ≥65 than < 65 (95% CI = 1.32-4.94), 2.48 times greater if a fall occurred in the bathroom vs. other locations (95% CI = 1.41-4.36), and 3.65 times greater if the fall occurred when hands-on assistance was provided without a gait belt, compared to hands-on assistance with a gait belt (95% CI = 1.34-9.97). CONCLUSIONS: Many factors associated with unassisted or injurious falls in rural hospitals were consistent with research conducted in larger facilities. A novel finding is that identifying a gait belt as an intervention decreased the odds of patients falling unassisted. Additionally, using a gait belt during an assisted fall decreased the odds of injury. We expanded upon other research that found an association between assistance during falls and injury by discovering that the manner in which a fall is assisted is an important consideration for risk mitigation.

The impact of post-fall huddles on repeat fall rates and perceptions of safety culture: a quasi-experimental evaluation of a patient safety demonstration project.

BACKGROUND: Conducting post-fall huddles is considered an integral component of a fall-risk-reduction program. However, there is no evidence linking post-fall huddles to patient outcomes or perceptions of teamwork and safety culture. The purpose of this study is to determine associations between conducting post-fall huddles and repeat fall rates and between post-fall huddle participation and perceptions of teamwork and safety culture. METHODS: During a two-year demonstration project, we developed a system for 16 small rural hospitals to report, benchmark, and learn from fall events, and we trained them to conduct post-fall huddles. To calculate a hospital's repeat fall rate, we divided the total number of falls reported by the hospital by the number of unique medical record numbers associated with each fall. We used Spearman correlations with exact P values to determine the association between the proportion of falls followed by a huddle and the repeat fall rate. At study end, we used the TeamSTEPPS® Teamwork Perceptions Questionnaire (T-TPQ) to assess perceptions of teamwork support for fall-risk reduction and the Hospital Survey on Patient Safety Culture (HSOPS) to assess perceptions of safety culture. We added an item to the T-TPQ for respondents to indicate the number of post-fall huddles in which they had participated. We used a binary logistic regression with a logit link to examine the effect of participation in post-fall huddles on respondent-level percent positive T-TPQ and HSOPS scores. We accounted for clustering of respondents within hospitals with random effects using the GLIMMIX procedure in SAS/STAT. RESULT: Repeat fall rates were negatively associated with the proportion of falls followed by a huddle. As compared to hospital staff who did not participate in huddles, those who participated in huddles had more positive perceptions of four domains of safety culture and how team structure, team leadership, and situation monitoring supported fall-risk reduction. CONCLUSIONS: Post-fall huddles may reduce the risk of repeat falls. Staff who participate in post-fall huddles are likely to have positive perceptions of teamwork support for fall-risk reduction and safety culture because huddles are a team-based approach to reporting, adapting, and learning.

Evaluating the use of multiteam systems to manage the complexity of inpatient falls in rural hospitals.

OBJECTIVE: To evaluate the implementation and outcomes of evidence-based fall-risk-reduction processes when those processes are implemented using a multiteam system (MTS) structure. DATA SOURCES/STUDY SETTING: Fall-risk-reduction process and outcome measures from 16 small rural hospitals participating in a research demonstration and dissemination study from August 2012 to July 2014. Previously, these hospitals lacked a fall-event reporting system to drive improvement. STUDY DESIGN: A one-group pretest-posttest embedded in a participatory research framework. We required hospitals to implement MTSs, which we supported by conducting education, developing an online toolkit, and establishing a fall-event reporting system. DATA COLLECTION: Hospitals used gap analyses to assess the presence of fall-risk-reduction processes at study beginning and their frequency and effectiveness at study end; they reported fall-event data throughout the study. PRINCIPAL FINDINGS: The extent to which hospitals implemented 21 processes to coordinate the fall-risk-reduction program and trained staff specifically about the program predicted unassisted and injurious fall rates during the end-of-study period (January 2014-July 2014). Bedside fall-risk-reduction processes were not significant predictors of these outcomes. CONCLUSIONS: Multiteam systems that effectively coordinate fall-risk-reduction processes may improve the capacity of hospitals to manage the complex patient, environmental, and system factors that result in falls.

Middle Stone Age human teeth from Magubike rockshelter, Iringa Region, Tanzania.

In 2006, six isolated hominin teeth were excavated from Middle Stone Age (MSA) deposits at the Magubike rockshelter in southern Tanzania. They comprise two central incisors, one lateral incisor, one canine, one third premolar, and one fourth premolar. All are fully developed and come from the maxilla. None of the teeth are duplicated, so they may represent a single individual. While there is some evidence of post-depositional alteration, the morphology of these teeth clearly shares features with anatomically modern Homo sapiens. Both metric and non-metric traits are compared to those from other African and non-African dental remains. The degree of biological relatedness between eastern and southern African Stone Age hunter-gatherers has long been a subject of interest, and several characteristics of the Magubike teeth resemble those of the San of southern Africa. Another notable feature is that the three incisors are marked on the labial crown by scratches that are much coarser than microwear striations. These non-masticatory scratches on the Magubike teeth suggest that the use of the front teeth as tools included regularly repeated activities undertaken throughout the life of the individual. The exact age of these teeth is not clear as ESR and radiocarbon dates on associated snail shells give varying results, but a conservative estimate of their minimum age is 45,000 years.

Shell We Date? ESR Dating Sangamon Interglacial Episode Deposits at Hopwood Farm, IL.

During the Sangamon Episode, North America occasionally experienced warm climates. At Hopwood Farm, IL, a small kettle lake filled with sediment after the Illinois Episode glaciers retreated from southern Illinois. To date those deposits, 14 mollusc samples newly collected with associated sediment from three depths at Hopwood Farm were dated by standard electron spin resonance (ESR) dating. ESR can date molluscs from ~0.5 ka to >2 Ma in age with 5-10% precision, by comparing the accumulated radiation dose with the total radiation dose rate from the mollusc and its environment. Because all molluscs contained ≤0.6 ppm U, their ages do not depend on the assumed U uptake model. Using five different species, ESR analyses for 14 mollusc subsamples from Hopwood Farm showed that Unit 3, a layer rich in lacustrine molluscs, dates at 102 ± 7 ka to 90 ± 6 ka, which correlates with Marine (Oxygen) Isotope Stage 5c-b. Thus, the period with the highest non-arboreal pollen at Hopwood also correlates with the European Brørup, Dansgaard-Oeschger Event DO 23, a time period when climates were cooling and drying somewhat over the same period.

Shifting the paradigm: an assessment of the quality of fall risk reduction in Nebraska hospitals.

PURPOSE: To assess the prevalence of evidence-based fall risk reduction structures and processes in Nebraska hospitals; whether fall rates are associated with specific structures and processes; and whether fall risk reduction structures, processes, and outcomes vary by hospital type--Critical Access Hospital (CAH) versus non-CAH. METHODS: A cross-sectional survey of Nebraska's 83 general community hospitals, 78% of which are CAHs. We used a negative binomial rate model to estimate fall rates while adjusting for hospital volume (patient days) and the exact Pearson chi-square test to determine associations between hospital type and the structure and process of fall risk reduction. FINDINGS: Approximately two-thirds or more of 70 hospitals used 6 of 9 evidence-based universal fall risk reduction interventions; 50% or more used 14 of 16 evidence-based targeted interventions. After adjusting for hospital volume, hospitals in which teams integrated evidence from multiple disciplines and reflected upon data and modified polices/procedures based upon data had significantly lower total and injurious fall rates per 1,000 patient days than hospitals that did not. Non-CAHs were significantly more likely than CAHs to perform 5 organizational-level fall risk reduction processes. CAHs reported significantly greater total (5.9 vs 4.0) and injurious (1.7 vs 0.9) fall rates per 1,000 patient days than did non-CAHs. CONCLUSIONS: Hospital type was a significant predictor of fall rates. However, shifting the paradigm for fall risk reduction from a nursing-centric approach to one in which teams implement evidence-based practices and learn from data may decrease fall risk regardless of hospital type.

Naturalistic Decision Making in After-Action Review Meetings: The Implementation of and Learning from Post-Fall Huddles.

The purpose of this study was to add to our understanding of Naturalistic Decision Making (NDM) in healthcare, and how After Action Reviews (AARs) can be utilized as a learning tool to reduce errors. The study focused on the implementation of a specific form of AAR, a post-fall huddle, to learn from errors and reduce patient falls. Utilizing 17 hospitals that participated in this effort, information was collected on 226 falls over a period of 16 months. The findings suggested that the use of self-guided post-fall huddles increased over the time of the project, indicating adoption of the process. Additionally, the results indicate that the types of errors identified as contributing to the patient fall changed, with a reduction in task and coordination errors over time. Finally, the proportion of falls with less adverse effects (such as non-injurious falls) increased during the project time period. The results of this study fill a void in the NDM and AAR literature, evaluating the role of NDM in healthcare specifically related to learning from errors. Over time, self-guided AARs can be useful for some aspects of learning from errors.

Dating human occupation at Toca do Serrote das Moendas, São Raimundo Nonato, Piauí-Brasil by electron spin resonance and optically stimulated luminescence.

Excavation of Toca do Serrote das Moendas, in Piauí state, Brazil revealed a great quantity of fossil wild fauna associated with human remains. In particular, fossils of a cervid (Blastocerus dichotomus) were found, an animal frequently pictured in ancient rock wall paintings. In a well-defined stratum, two loose teeth of this species were found in close proximity to human bones. The teeth were independently dated by electron spin resonance (ESR) in two laboratories. The ages obtained for the teeth were 29 ± 3 ka (thousands of years) and 24 ± 1 ka. The concretion layer capping this stratum was dated by optically stimulated luminescence (OSL) of the quartz grains to 21 ± 3 ka. As these values were derived independently in three different laboratories, using different methods and equipment, these results are compelling evidence of early habitation in this area.

Monitoring tectonic uplift and paleoenvironmental reconstruction for marine terraces near Maǧaracik and Samandaǧ, Hatay Province, Turkey.

Near Hatay, the Antakya-Samandag-Cyprus Fault (ASCF), East Anatolian and Dead Sea Fault Zones, the large faults that form the edges of the African, Anatolian, Cyprus and Arabian Plates, all produce large earthquakes, which have decimated Hatay repeatedly. Near Samandag, Hatay, differential vertical displacement on the ASCF has uplifted the southeastern side relative to northwestern side, producing large fault scarps that parallel the Asi (Orontes) River. Tectonic uplift coupled with Quaternary sealevel fluctuations has produced several stacked marine terraces stranded above current sealevel. This study dated 24 mollusc samples from 10 outcrops on six marine terraces near Samandag electron spin resonance (ESR). Ages were calculated using time-averaged and volumetrically averaged external dose rates, modelled by assuming typical water depths for the individual species and sediment thicknesses estimated from geological criteria. Uplift rates were then calculated for each fault block. At all the Magaracik terraces, the dates suggest that many shells were likely reworked. On the 30 m terrace at Magaracik IV (UTM 766588-3999880), Lithophagus burrows with in situ shells cross the unconformity. One such shell dated to 62 ± 6 ka, setting the minimum possible age for the terrace. For all the Magaracik terraces at ∼30 m above mean sealevel (amsl), the youngest ages for the reworked shells, which averaged 60 ± 3 ka for six separate analyses, sets the maximum possible age for this unit. Thus, the terrace must date to 60-62 ± 3 ka, at the MIS 3/4 boundary when temperatures and sealevels were fluctuating rapidly. Older units dating to MIS 7, 6, and 5 likely were being eroded to supply some fossils found in this terrace. At Magaracik Dump (UTM 765391-4001048), ∼103 m amsl, Ostrea and other shells were found cemented in growth position to the limestone boulders outcropping there <2.0 m above a wave-eroded notch. If the oysters grew at the same time as the wave-cut notch and the related terrace, the date, 91 ± 13 ka, for the oysters, this fault block has been uplifted at 1.19 ± 0.15 m ky(-1), since MIS 5c. At Samandag Kurt Stream at 38 m amsl, molluscs were deposited fine sandy gravel, which was likely formed in a large tidal channel. Four molluscs averaged 116 ± 5 ka. If these molluscs have not been reworked, this fault block has uplifted at 0.34 ± 0.05 m ky(-1) since the MIS 5d/5e boundary. The differences in these uplift rates suggests that at least one, and possibly two, hitherto undiscovered faults may separate the Magaracik Dump site from the other Magaracik sites and from the Samandag Kurt Stream site.

The CTSA Consortium's Catalog of Assets for Translational and Clinical Health Research (CATCHR).

The 61 CTSA Consortium sites are home to valuable programs and infrastructure supporting translational science and all are charged with ensuring that such investments translate quickly to improved clinical care. Catalog of Assets for Translational and Clinical Health Research (CATCHR) is the Consortium's effort to collect and make available information on programs and resources to maximize efficiency and facilitate collaborations. By capturing information on a broad range of assets supporting the entire clinical and translational research spectrum, CATCHR aims to provide the necessary infrastructure and processes to establish and maintain an open-access, searchable database of consortium resources to support multisite clinical and translational research studies. Data are collected using rigorous, defined methods, with the resulting information made visible through an integrated, searchable Web-based tool. Additional easy-to-use Web tools assist resource owners in validating and updating resource information over time. In this paper, we discuss the design and scope of the project, data collection methods, current results, and future plans for development and sustainability. With increasing pressure on research programs to avoid redundancy, CATCHR aims to make available information on programs and core facilities to maximize efficient use of resources.

On the industrial attributions of the Aterian and Mousterian of the Maghreb.

North Africa is quickly emerging as one of the more important regions yielding information on the origins of modern Homo sapiens. Associated with significant fossil hominin remains are two stone tool industries, the Aterian and Mousterian, which have been differentiated, respectively, primarily on the basis of the presence and absence of tanged, or stemmed, stone tools. Largely because of historical reasons, these two industries have been attributed to the western Eurasian Middle Paleolithic rather than the African Middle Stone Age. In this paper, drawing on our recent excavation of Contrebandiers Cave and other published data, we show that, aside from the presence or absence of tanged pieces, there are no other distinctions between these two industries in terms of either lithic attributes or chronology. Together, these results demonstrate that these two 'industries' are instead variants of the same entity. Moreover, several additional characteristics of these assemblages, such as distinctive stone implements and the manufacture and use of bone tools and possible shell ornaments, suggest a closer affinity to other Late Pleistocene African Middle Stone Age industries rather than to the Middle Paleolithic of western Eurasia.

A theory-driven, longitudinal evaluation of the impact of team training on safety culture in 24 hospitals.

BACKGROUND: Effective teamwork facilitates collective learning, which is integral to safety culture. There are no rigorous evaluations of the impact of team training on the four components of safety culture-reporting, just, flexible and learning cultures. We evaluated the impact of a year-long team training programme on safety culture in 24 hospitals using two theoretical frameworks. METHODS: We used two quasi-experimental designs: a cross-sectional comparison of hospital survey on patient safety culture (HSOPS) results from an intervention group of 24 hospitals to a static group of 13 hospitals and a pre-post comparison of HSOPS results within intervention hospitals. Dependent variables were HSOPS items representing the four components of safety culture; independent variables were derived from items added to the HSOPS that measured the extent of team training, learning and transfer. We used a generalised linear mixed model approach to account for the correlated nature of the data. RESULTS: 59% of 2137 respondents from the intervention group reported receiving team training. Intervention group HSOPS scores were significantly higher than static group scores in three dimensions assessing the flexible and learning components of safety culture. The distribution of the adoption of team behaviours (transfer) varied in the intervention group from 2.8% to 31.0%. Adoption of team behaviours was significantly associated with odds of an individual reacting more positively at reassessment than baseline to nine items reflecting all four components of safety culture. CONCLUSIONS: Team training can result in transformational change in safety culture when the work environment supports the transfer of learning to new behaviour.

ESR dating pleistocene barnacles from BC and Maine: a new method for tracking sea level change.

Barnacles have never been successfully dated by electron spin resonance (ESR). Living mainly in the intertidal zone, barnacles die when sea level changes cause their permanent exposure. Thus, dating the barnacles dates past sea level changes. From this, we can measure apparent sea level changes that occur due to ocean volume changes, crustal isostasy, and tectonics. ESR can date aragonitic mollusc shells ranging in age from 5 ka to at least 500 ka. By modifying the standard ESR method for molluscs to chemically dissolve 20 microm from off the shells, six barnacle samples from Norridgewock, Maine, and Khyex River, British Columbia, were tested for suitability for ESR dating. Due to Mn2+ interference peaks, the four Maine barnacle samples were not datable by ESR. Two barnacles from BC, which lacked Mn2+ interference, yielded a mean ESR age of 15.1 +/- 1.0 ka. These ages agree well with 14C dates on the barnacles themselves and wood in the overlying glaciomarine sediment. Although stability tests to calculate the mean dating signal lifetime and more ESR calibration tests against other barnacles of known age are needed to ensure the method's accuracy, ESR can indeed date Balanus, and thus, sea level changes.

Initial excavation and dating of Ngalue Cave: a Middle Stone Age site along the Niassa Rift, Mozambique.

Direct evidence for a systematic occupation of the African tropics during the early late Pleistocene is lacking. Here, we report a record of human occupation between 105-42ka, based on results from a radiometrically-dated cave section from the Mozambican segment of the Niassa (Malawi/Nyasa) Rift called Ngalue. The sedimentary sequence from bottom to top has five units. We concentrate on the so-called "Middle Beds," which contain a Middle Stone Age industry characterized by the use of the discoidal reduction technique. A significant typological feature is the presence of formal types such as points, scrapers, awls, and microliths. Special objects consist of grinders/core-axes covered by ochre. Ngalue is one of the few directly-dated Pleistocene sites located along the biogeographical corridor for modern human dispersals that links east, central, and southern Africa, and, with further study, may shed new light on hominin cave habitats during the late Pleistocene.