Eastern Sites Research Articles

Rice’s whales in the northwestern Gulf of Mexico: call variation and occurrence beyond the known core habitat

The endangered Rice’s whaleBalaenoptera ricei, with fewer than 100 individuals remaining, is the only year-round resident baleen whale found in the Gulf of Mexico (GOM) and occurs primarily along the northeastern shelf break near De Soto Canyon. Historical whaling records and predictive density modeling suggest that these whales potentially could occur more broadly throughout the GOM. High levels of anthropogenic activities in the GOM, including oil and gas exploration and extraction, fisheries, shipping, and the unprecedentedDeepwater Horizonoil spill, highlight the need to better understand the distribution, ecology, and threats to this small population to improve protection of these endangered whales. We used long-term passive acoustic recordings from the northwestern GOM shelf break to explore the extent of Rice’s whale distribution in the northern GOM and to evaluate whether they exhibit seasonal movements throughout this range. We describe 6 new stereotyped variants of Rice’s whale long-moan calls, found predominantly in the western GOM, that share distinctive features with typical eastern long-moans, including a 150 Hz starting tone, an approximately 100 Hz tail with amplitude modulation, and a long call duration ranging from 10 to 35 s. Western long-moan variants were detected at 3 northwestern sites, occurring sporadically throughout the year on as many as 16% of days at the westernmost site, and infrequently at an eastern core-habitat site. These results indicate that some whales persistently occur over a broader range in the GOM than previously understood, which is important to consider when designating critical habitat and assessing threats to this Critically Endangered species.

Converging and diverging burn rates in North American boreal forests from the Little Ice Age to the present

Warning This article contains terms, descriptions, and opinions used for historical context that may be culturally sensitive for some readers. Background Understanding drivers of boreal forest dynamics supports adaptation strategies in the context of climate change. Aims We aimed to understand how burn rates varied since the early 1700s in North American boreal forests. Methods We used 16 fire-history study sites distributed across such forests and investigated variation in burn rates for the historical period spanning 1700–1990. These were benchmarked against recent burn rates estimated for the modern period spanning 1980–2020 using various data sources. Key results Burn rates during the historical period for most sites showed a declining trend, particularly during the early to mid 1900s. Compared to the historical period, the modern period showed less variable and lower burn rates across sites. Mean burn rates during the modern period presented divergent trends among eastern versus northwestern sites, with increasing trends in mean burn rates in most northwestern North American sites. Conclusions The synchronicity of trends suggests that large spatial patterns of atmospheric conditions drove burn rates in addition to regional changes in land use like fire exclusion and suppression. Implications Low burn rates in eastern Canadian boreal forests may continue unless climate change overrides the capacity to suppress fire.

Spatial distribution of atmospheric oil and natural gas volatile organic compounds in the Northern Colorado Front Range

Methane and nonmethane volatile organic compounds (VOCs) were monitored near Boulder in the Northern Colorado Front Range to investigate their spatial distribution and sources as a part of the Front Range Air Pollution and Photochemistry Experiment (FRAPPE) and the Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) campaign, in summer 2014. A particular emphasis was the study of the contribution of emissions from oil and natural gas (O&NG) operations on the regional air quality. One network extended along an elevation gradient from the City of Boulder (elevation ≈1,600 m) to the University of Colorado Mountain Research Station (≈2900 m) on the eastern slopes of the Rocky Mountains. Light alkane petroleum hydrocarbons had the highest mole fraction of the VOCs that could be analyzed with the applied techniques. The longer lived VOCs ethane and propane decreased with increasing elevation, suggesting that Boulder and the surrounding plains were a source of these anthropogenic compounds. VOC diurnal time series showed a few events with elevated mole fractions at the mountain sites, which were likely the result of the upslope transport of plumes with elevated VOCs from the plains. Within the other site network, which extended into suburban East Boulder County (EBC), VOCs were monitored at 5 sites increasingly close to O&NG development in the Denver Julesburg Basin. Mean mole fractions and variability of primarily O&NG-associated VOCs (ethane, propane, butane isomers) increased by a factor of 2.4–5.2 with closer proximity to the O&NG producing region. Median mole fractions of C2–C5 n-alkanes and of imuch-butane at the EBC sites were higher than those previously reported from 28 larger urban areas in the United States. Among the VOCs that could be quantified with the gas chromatography methods, VOCs most clearly associated to O&NG-related emissions (C2–C5 alkanes) accounted for 52%–79% of the VOC hydroxyl radical reactivity (OHR). The horizontal gradient in OHR of the considered VOCs, with ≈3 times higher values at the furthest eastern sites, points toward higher chemical reactivity and ozone production potential from these ozone precursors in the eastern area of the county than within the City of Boulder.

First insights into coral recruit and juvenile abundances at remote Aldabra Atoll, Seychelles.

Coral recruitment and successive growth are essential for post-disturbance reef recovery. As coral recruit and juvenile abundances vary across locations and under different environmental regimes, their assessment at remote, undisturbed reefs improves our understanding of early life stage dynamics of corals. Here, we first explored changes in coral juvenile abundance across three locations (lagoon, seaward west and east) at remote Aldabra Atoll (Seychelles) between 2015 and 2019, which spanned the 2015/16 global coral bleaching event. Secondly, we measured variation in coral recruit abundance on settlement tiles from two sites (lagoon, seaward reef) during August 2018-August 2019. Juvenile abundance decreased from 14.1 ± 1.2 to 7.4 ± 0.5 colonies m-2 (mean ± SE) during 2015-2016 and increased to 22.4 ± 1.2 colonies m-2 during 2016-2019. Whilst juvenile abundance increased two- to three-fold at the lagoonal and seaward western sites during 2016-2018 (from 7.7-8.3 to 17.3-24.7 colonies m-2), increases at the seaward eastern sites occurred later (2018-2019; from 5.8-6.9 to 16.6-24.1 colonies m-2). The composition of coral recruits on settlement tiles was dominated by Pocilloporidae (64-92% of all recruits), and recruit abundance was 7- to 47-fold higher inside than outside the lagoon. Recruit abundance was highest in October-December 2018 (2164 ± 453 recruits m-2) and lowest in June-August 2019 (240 ± 98 recruits m-2). As Acroporid recruit abundance corresponded to this trend, the results suggest that broadcast spawning occurred during October-December, when water temperature increased from 26 to 29°C. This study provides the first published record on coral recruit abundance in the Seychelles Outer Islands, indicates a rapid (2-3 years) increase of juvenile corals following a bleaching event, and provides crucial baseline data for future research on reef resilience and connectivity within the region.

Zhoukoudian Upper Cave personal ornaments and ochre: Rediscovery and reevaluation

Personal ornaments have become a key cultural proxy to investigate cognitive evolution, modern human dispersal, and population dynamics. Here, we reassess personal ornaments found at Zhoukoudian Upper Cave and compare them with those from other Late Paleolithic Northern Chinese sites. We reappraise the information provided by Pei Wen Chung on Upper Cave personal ornaments lost during World War II and analyze casts of 17 of them, along with two unpublished objects displayed at the Zhoukoudian Site Museum and three original perforated teeth rediscovered at the Zhoukoudian Site Museum. We apply archeozoological, technological and use-wear analyses to document variation in ornamental practices and their change throughout the site stratigraphy. Badger, fox, red deer, sika deer, marten, and tiger teeth as well as carp bone, bird bone, Anadara shell, limestone beads, and perforated pebble appear to have been the preferred objects used as ornaments by Upper Cave visitors. Multivariate analysis of technological data highlights a correspondence between cultural layers and perforation techniques, with radial incising being typical of layer L2 and bidirectional incising of L4. The three rediscovered badger canines display features suggesting they were sewed on clothing rather than suspended from necklaces or bracelets. Elemental scanning electron microscopy coupled with energy dispersive X-ray spectromety and mineralogical (μ-Raman) analyses of red residues adhering to the rediscovered teeth indicate these objects were originally coated with ochre and identify variations that match differences in technology. The two ornaments exhibited at the Zhoukoudian Site Museum are ancient teeth that were recently perforated and should be excluded from the Upper Cave assemblage. A seriation of Late Paleolithic ornaments found at Northern Chinese sites identifies a clear-cut difference in preferred ornament types between western and eastern sites, interpreted as reflecting two long-lasting traditions in garment symbolic codes.

Spatial separation of microbial communities reflects gradients of salinity and temperature in offshore sediments from Shenzhen, south China

The rapid industrialization and urbanization around the coastal region have resulted in a pollution pressure in Shenzhen, one of the most developed cities in China. However, microbial communities of coastal sediment and their environment quality are far from understood. Here, 16S rRNA gene sequencing was conducted to investigate the microbial community of offshore sediments from 20 coastal areas in Shenzhen and the factors affecting that variability. Results showed there was a significant difference on the diversity among the 20 sites, and notable difference between the western and eastern offshore sediments were observed. The microbial community was dominated by Nitrosopumilaceae, Flavobacteriaceae, Pirellulaceae, Woeseiaceae, Anaerolineaceae and Saprospiraceae at the family level. The abundance of Woeseia, Candidatus Nitrosopumilus, Muriicola, and Rhodopirellula were higher in samples from eastern sites, while Cyanobium PCC-6307, Acinetobacter, Sulfurovum, Robiginitalea, and Nitrospira were enriched in western sediment samples. PICRUSt-based prediction of metagenomes indicated the KEGG pathways about amino acid metabolism, carbohydrate metabolism, and energy metabolism were significantly more abundant in eastern sediments. Moreover, salinity, pH and temperature were the important environmental factors shaping the structure of microbial communities. These findings are important for understanding the relationships between bacterial communities and environmental conditions in coastal ecosystems, and provide a scientific basis for offshore ecosystem conservation.

Identification of breeding grounds and annual routines of the newly discovered bohaii subspecies of Black-tailed Godwits

ABSTRACT The Bohai Black-tailed Godwit (Limosa limosa bohaii) is a newly discovered subspecies in the East Asian-Australasian Flyway. Based on satellite tracking of 21 individuals that were tagged in northern Bohai Bay, China, from 2016 to 2018, we here describe the annual cycle of this subspecies. All the birds had Thailand as their southernmost ‘winter’ destination. The spring departure was in late March during northward migration, Bohai Bay was the first stopping site where they spent on average 39 days (± SD = 6 d), followed by Inner Mongolia and Jilin province (stopping for 8 d ± 1 d). The arrival of the breeding grounds in the Russian Far East was centred in late May. Two breeding sites were detected, with average locations 1100 km apart; the eastern site was beyond the known Asian breeding distribution of the Black-tailed Godwit. Southward migration started in late June, with the godwits tending to make longer stops at the same two main stopping sites used in the spring, i.e. Inner Mongolia and Jilin province (32 ± 5 d) and Bohai Bay (44 ± 8 d), with some individuals making a third stop in the middle-lower reaches of the Yangtze River in southern China (12 ± 4 d). By the end of September, most tracked individuals had arrived in Thailand. Compared with the previously known subspecies, bohaii godwits have strikingly different schedules of migration and moult, this study thus adding to the knowledge about intraspecific diversity of black-tailed godwits in the East Asian-Australian Flyway.

Reduction of Bias and Uncertainty in Regional Seismic Site Amplification Factors for Seismic Hazard and Risk Analysis

Site amplification factors in National Building Codes are typically specified as a function of the average shear wave velocity over the first 30 m (Vs30) or site class (A, B, C, D and E) for defined ranges of Vs30 and/or ranges of depth to bedrock. However, a single set of amplification factors may not be representative of site conditions across the country, introducing a bias in seismic hazard and seismic risk analyses. This is exemplified by significant differences in geological settings between East and West coast locations in North America. Western sites are typically characterized by lower impedance contrasts between recent surface deposits and bedrock in comparison to Eastern sites. In North America, site amplification factors have been derived from a combination of field data on ground motions recorded during West Coast earthquakes and numerical models of site responses that are meant to be representative of a wide variety of soil profiles and ground motions. The bias on amplifications and their impact on seismic hazards is investigated for the Montreal area, which ranks second for seismic risks in Canada in terms of population and hazard (PGA of 0.25 g for a 2475 years return period). Representative soil profiles at several locations in Montreal are analyzed with 1-D site response models for natural and synthetic ground motions scaled between 0.1 to 0.5 g. Since bedrock depths are typically shallow (<30 m) across the island, bedrock shear wave velocities have a significant influence on the impedance contrast and amplifications. Bedrock shear wave velocity is usually very variable due to the differences in rock formations, level of weathering and fracturing. The level of this uncertainty is shown to be greatly decreased when rock quality designation (RQD) data, common information when bore hole data are logged, is available since it is highly correlated with both shear and compression wave velocities. The results are used to derive region-specific site amplification factors as a function of both Vs30 and site fundamental frequency and compared to those of the National Building Code of Canada (2015). The results of the study indicate that there are large uncertainties associated with these parameters due to variability in soil profiles, soil properties and input seismic ground motions. Average and confidence intervals for the mean and for predictions of amplification factors are calculated for each site class to quantify this uncertainty. Amplifications normalized relative to class C are obtained by accounting for the correlation between site class amplifications for given ground motions. Non-linearity in the analysis of equivalent linear 1-D site response is taken into account by introducing the non-linear G/Gmax and damping ratios curves. In this method, it is assumed that the shear strain compatible shear modulus and damping ratio values remains constant throughout the duration of the seismic excitation. This assumption is not fully applicable to a case when loose saturated soil profile undergo heavy shaking (PGA > 0.3 g). In this study, all simulations with input motion PGA >0.3 g have been performed by using the EL method instead of the NL method considering that cohesive soils (clay and silt) at Montreal sites are stiff and cohesionless soils (sand and gravel) are considerably dense. In addition, the field and laboratory data required to perform NL analyses are not currently available and may be investigated in future works.

Impact of Drought and Changing Water Sources on Water Use and Soil Salinity of Almond and Pistachio Orchards: 1. Observations

Soil salinity increases when growers are forced to use higher salinity irrigation waters due to water shortages. It is necessary to estimate the impact of irrigation water on soil properties and conditions for crop growth to manage the effects of salinity on perennial crops. Therefore, in this study, we monitored root zone salinity in five almond and pistachio orchards in eastern and western San Joaquin Valley (SJV), California (CA). Volumetric soil water contents and bulk electrical conductivities were measured at four root-zone depths. Evapotranspiration was measured by eddy covariance along with three other types of data. The first is seasonal precipitation and irrigation patterns, including the temporal distribution of rains, irrigation events, and irrigation water salinity. The second is soil chemistry, including the initial sodium adsorption ratio (SAR) and soil solute electrical conductivity (ECe). The third type is the physical properties, including soil type, hydraulic conductivity, and bulk density. As expected, we found low salinity at the eastern sites and higher salinity at the western sites. The western sites have finer textured soils and lower quality irrigation water; measured actual ET was about 90% of modeled crop ET. Across the three western sites, the annual average apparent leaching fraction ranged from 11 to 28%. At the eastern sites, measured ET almost exactly matched modeled crop ET each year. Apparent leaching fractions in the eastern sites were approximately 20%.

Factors explaining the composition and diversity of vascular plant understories along a transcontinental gradient in the Canadian boreal forest

AbstractAimImpacts of longitudinal gradients on species distributions have received less attention than latitudinal gradients. In Canada, precipitation varies longitudinally, with direct effects on plant growth and fire regimes. Despite the geographical extent of Canadian boreal forests, vascular plant diversity is relatively limited, with just under 300 species. Understorey communities comprise most of this diversity and play key roles in forests, affecting succession, nutrient cycling and wildlife habitat. Our objective was to evaluate the relative impacts of local and regional environmental conditions on vascular plant community composition and diversity in the boreal forest.LocationSampling took place in 33 trembling aspen (Populus tremuloides) stands along a transcontinental gradient in precipitation and fire regimes in boreal Canada.MethodsWe measured community composition and vegetation diversity indices of the vascular understorey in 400‐m2 plots and measured environmental variables at the local (drainage, nutrient and light availability, site heterogeneity) and regional (annual temperature and precipitation, fire weather index, landscape heterogeneity) scales. Multivariate analyses and hierarchical model selection were used to analyze patterns.ResultsSpecies composition varied longitudinally, with western and eastern species pools. Western indicator species tended to be fire‐adapted pioneer species, while indicator species at eastern sites were fire avoiders and late‐successional species. Species richness and intra‐site beta diversity seemed primarily driven by local variables and did not vary across the country. Species evenness, however, was slightly higher in the western region and decreased under higher precipitation, colder temperatures, and higher landscape‐level heterogeneity.ConclusionOur results suggested that even for similar canopy composition environmental variables play a key role in the establishment of plant communities and structure local plant assemblages by selecting or eliminating species from the regional pool, which was also controlled by fire regimes.

Persistence and resistance: survival mechanisms of Candidatus Dormibacterota from nutrient-poor Antarctic soils.

Candidatus Dormibacterota is an uncultured bacterial phylum found predominantly in soil that is present in high abundances within cold desert soils. Here, we interrogate nine metagenome-assembled genomes (MAGs), including six new MAGs derived from soil metagenomes obtained from two eastern Antarctic sites. Phylogenomic and taxonomic analyses revealed these MAGs represent four genera and five species, representing two order-level clades within Ca. Dormibacterota. Metabolic reconstructions of these MAGs revealed the potential for aerobic metabolism, and versatile adaptations enabling persistence in the 'extreme' Antarctic environment. Primary amongst these adaptations were abilities to scavenge atmospheric H2 and CO as energy sources, as well as using the energy derived from H2 oxidation to fix atmospheric CO2 via the Calvin-Bassham-Benson cycle, using a RuBisCO type IE. We propose that these allow Ca. Dormibacterota to persist using H2 oxidation and grow using atmospheric chemosynthesis in terrestrial Antarctica. Fluorescence in situ hybridization revealed Ca. Dormibacterota to be coccoid cells, 0.3-1.4μm in diameter, with some cells exhibiting the potential for a symbiotic or syntrophic lifestyle.

Caregivers’ estimate of early childhood developmental status in rural Uganda: a cross-sectional study

ObjectiveTo characterise developmental milestones among young children living in rural communities in Uganda.DesignCross-sectional study.SettingIganga-Mayuge Health and Demographic Surveillance Site in rural eastern Uganda.ParticipantsA total of 720 caregivers of children aged...

Trees at a Moderately Arid Site Were More Sensitive to Long-Term Drought

Climate change has dramatically altered the frequency and intensity of droughts, thereby altering tree growth. Understanding whether tree growth in semiarid areas in response to long-term drought and the post-drought recovery rate of tree growth vary along moisture gradients is crucial for predicting future forest change. Here, we assessed the spatial variation in both the growth resistance of Qinghai spruce (Picea crassifolia Kom.) to long-term drought and its post-drought recovery using a stand-total sampling strategy along a moisture gradient that covered three sites (with an annual precipitation of 330.4, 394.2, and 515.9 mm for the western, middle, and eastern sites, respectively) with six plots. Resistance and recovery were evaluated by analyzing the tree growth trends during a long-term drought period (1980–2001) and the subsequent post-drought period (2001–2013), respectively. Our results indicate that the trees with the highest temporal stability were those at the wetter eastern site; specifically, during the long-term drought period, the trees at the wetter eastern site showed the highest resistance (−0.015) and the lowest recovery (0.002). The trees in moderately arid conditions were much more sensitive to climate change than those at the relatively arid western site, showing the lowest resistance (−0.050) and highest recovery (0.020). Climate change had the strongest impact on tree growth at the moderately arid site, contributing 60.6% to the tree growth decreasing trend during the long-term drought period and 65.4% to the tree recovery during the post-drought period, respectively. Climate change had a lower impact on tree growth at the wet and dry sites, contributing less than 50% to the tree growth trends at these sites. The results indicate that a trade-off relationship exists between resistance and recovery at the different sites; that is, the highly resistant trees at the wetter eastern site tend to have lower recovery, whereas the weakly resistant trees at the moderately arid site tend to have higher recovery. These results have implications for predicting tree growth in response to future climate change.

The neo‐nationalist ascendency: further thoughts on class, value and the return of the repressed

The neo‐nationalist ascendency: further thoughts on class, value and the return of the repressed

Can isoniazid preventive therapy be scaled up rapidly? Lessons learned in Kenya, 2014-2018.

BACKGROUND: TB is the leading cause of mortality among people living with HIV (PLHIV), for whom isoniazid preventive therapy (IPT) has a proven mortality benefit. Despite WHO recommendations, countries have been slow in scaling up IPT. This study describes processes, challenges, solutions, outcomes and lessons learned during IPT scale-up in Kenya.METHODS: We conducted a desk review and analyzed aggregated Ministry of Health (MOH) IPT enrollment data from 2014 to 2018 to determine trends and impact of program activities. We further analyzed IPT completion reports for patients initiated from 2015 to 2017 in 745 MOH sites in Nairobi, Central, Eastern and Western Kenya.RESULTS: IPT was scaled up 75-fold from 2014 to 2018: the number of PLHIV covered increased from 9,981 to 749,890. The highest percentage increases in the cumulative number of PLHIV on IPT were seen in the quarters following IPT pilot projects in 2014 (49%), national launch in 2015 (54%), and HIV treatment acceleration in 2016 (158%). Among 250,069 patients initiating IPT from 2015 to 2017, 97.5% completed treatment, 0.2% died, 0.8% were lost to follow-up, 1.0% were not evaluated, and 0.6% discontinued treatment.CONCLUSIONS: IPT can be scaled up rapidly and effectively among PLHIV. Deliberate MOH efforts, strong leadership, service delivery integration, continuous mentorship, stakeholder involvement, and accountability are critical to program success.

Monitoring of Land Subsidence in the Po River Delta (Northern Italy) Using Geodetic Networks

The Po River Delta (PRD, Northern Italy) has been historically affected by land subsidence due to natural processes and human activities, with strong impacts on the stability of the natural ecosystems and significant socio-economic consequences. This paper is aimed to highlight the spatial and temporal evolution of the land subsidence in the PRD area analyzing the geodetic observations acquired in the last decade. The analysis performed using a moving window approach on Continuous Global Navigation Satellite System (CGNSS) time-series indicates that the velocities, in the order of 6 mm/year, are not affected by significant changes in the analyzed period. Furthermore, the use of non-permanent sites belonging to a new GNSS network (measured in 2016 and 2018) integrated with InSAR data (from 2014 to 2017) allowed us to improve the spatial coverage of data points in the PRD area. The results suggest that the land subsidence velocities in the easternmost part of the area of interest are characterized by values greater than the ones located in the western sectors. In particular, the sites located on the sandy beach ridge in the western sector of the study area are characterized by values greater than −5 mm/year, while rates of about −10 mm/year or lower have been observed at the eastern sites located in the Po river mouths. The morphological analysis indicates that the land subsidence observed in the PRD area is mainly due to the compaction of the shallow layers characterized by organic-rich clay and fresh-water peat.

An uncertainty-focused database approach to extract spatiotemporal trends from qualitative and discontinuous lake-status histories

Changes in lake status are often interpreted as palaeoclimate indicators due to their dependence on precipitation and evaporation. The Global Lake Status Database (GLSDB) has since long provided a standardised synopsis of qualitative lake status over the last 30,000 14C years. Potential sources of uncertainty however are not recorded in the GLSDB. Here we present an updated and improved relational-database framework that incorporates uncertainty in both chronology and the interpretation of palaeoenvironmental data. The database uses peer-reviewed palaeolimnological studies to produce a consensus on qualitative lake-status histories, whose chronologies are revised and standardized through the recalibration of radiocarbon dates and the application of Bayesian age-depth modelling for stratigraphic archives. Quantitative information on absolute water-level elevation is preserved if available from geomorphological sources. We also propose a new probabilistic analytical framework that accounts for these uncertainties to reconstruct synoptic, integrated environmental signals. The process is based on a Monte Carlo algorithm that iteratively samples individual lake-status histories within the limits of their uncertainties to produce many possible scenarios. We then use Recursively-Subtracted Empirical Orthogonal Function analysis to extract dominant patterns of lake-status variability from these scenarios.As a proof of concept, we apply this framework to 67 sites in eastern and southern Africa whose lake-status histories cover part of the late Pleistocene and/or Holocene. We show that, despite the sometimes large temporal and interpretation uncertainties, and the inclusion of highly discontinuous lake-status time series, identifying the major known millennial-scale climatic phases during the last 20,000 years is possible. Our framework was also able to identify an antiphased response between the lake basins in eastern and interior southern Africa to these changes. We propose that our new database and methodology framework serves as a template for efficient lake-status data synthesis, encourages the incorporation of lake-status data in palaeoclimate syntheses, and expands the possibilities for the use of such data in the evaluation of climate models.

Phytoplankton assessment and Non-Indigenous species monitoring through eDNA metabarcoding in marine ecosystems

Invasive Alien Species (IAS) are one of the most contributing constituents of biodiversity loss with the distribution range of an increasing number of IAS being artificially re-shaped by human activities. Rapid and effective tools are therefore needed in order to monitor changes in biodiversity and the dispersal of IAS. Molecular tools such as environmental DNA metabarcoding are being progressively included in the tool kit for IAS monitoring, however, the literature is largely focused on metazoans markers targeting regions such as COI and 18S and scarce studies include a marker for plants or algae. Here, we have tested a marker in ribulose-1,5-bisphosphate carboxylase-oxygenase chloroplast region to assess phytoplankton through environmental DNA metabarcoding. Several sample types (low and high-volume water filtration, sediment grabs, net tows) were deployed at twelve study sites along the Irish coast to determine which technique would perform better for the targeted group. A total of eleven NIS were detected during the study. Low-volume surface water filtering exceeded in NIS detection and recovered the highest diversity with 123 species detected. High volume samplers were the ones recovering the lowest number of OTUs (N= 53). Western sites (Galway Bay) had greater diversity and the highest number of total NIS compared to eastern sites in Carlingford, Dublin and Waterford. These results have shown the need for a specific IAS surveillance and has served as a basis to implement the use of eDNA metabarcoding and algae markers in future monitoring programs.

Abstract PS7-53: Assessing racial differences in patients with metastatic triple-negative breast cancer: Real-world evidence from US community oncology practices

Abstract Background: Metastatic triple-negative breast cancer (mTNBC) is an aggressive tumor phenotype with a poor prognosis and few treatment options. The prevalence of mTNBC is disproportionately higher among African American (AA) women, compared with white women. Data identifying the drivers of racial differences in mTNBC or characterizations of treatment patterns and clinical outcomes in AA patients with mTNBC are limited. Methods: This retrospective study used the Flatiron Health electronic health record-derived de-identified database (January 2011-March 2020). Adult AA and white female patients with confirmed mTNBC treated in US community oncology practices were included. Differences in mTNBC prevalence among AA and white patients were assessed by age, health insurance coverage, geographic region and stage at initial diagnosis. Descriptive statistics were used to analyze clinical characteristics, treatment patterns and time to treatment initiation between AA and white patients. Racial differences in overall survival (OS) were examined using Kaplan-Meir analysis and a multivariate Cox regression model. Results: Of the 21,804 Flatiron patients diagnosed with metastatic breast cancer (mBC), 2116 eligible patients with mTNBC were identified; 383 (18%) were AA and 1155 (55%) were white. TNBC prevalence was twice as high among AA patients (23%) than white patients (12%). Racial differences in TNBC prevalence (AA vs white patients) were particularly higher among patients aged 45 to 65 y (26% vs 13%), patients in the Northeast (27% vs 11%) and those with initial diagnosis at Stage II (30% vs 13%) or Stage III (27% vs 15%). AA patients with TNBC were younger (mean age: 60 vs 63 y; P < 0.001) and more likely to have Medicaid at the time of diagnosis (10% vs 3%; P < 0.001) than white patients. Clinical characteristics were generally similar between AA and white patients, including the distribution of staging at initial diagnosis, disease recurrence, Eastern Cooperative Oncology Group performance status (ECOG PS), and sites and number of metastases. Regardless of race, 25% of all patients with mTNBC had no documentation of receiving anti-cancer treatment in the database. Untreated patients in both race groups were older, had poorer ECOG PS and were less likely to have visceral metastases than treated patients (all P < 0.001); they also had poorer survival than treated patients (median OS: 4.7 vs 13.1 months from diagnosis for all treated patients; unadjusted hazard ratio [HR], 0.51 [95% CI: 0.46, 0.57]). Among both AA and white treated patients, single-agent chemotherapy was the most prevalent first-line treatment (most common agent: capecitabine). More than half of treated patients initiated treatment in < 30 days, and median time-to-treatment initiation did not differ by race. Although OS was numerically lower in AA patients (median OS, 10.3 vs 11.9 months in white patients), the difference was not significant when adjusted for prognostic and treatment factors (adjusted HR, 1.09 [95% CI: 0.95, 1.25]). Conclusions: The prevalence of mTNBC was twice as high among AA compared with white patients in US community oncology practices. Unlike prior research, race did not show an association with OS in this population. Regardless of race, 1 in every 4 patients with mTNBC had not received documented anti-cancer treatment, potentially due to poor PS and concerns about treatment tolerance. OS was poor for both AA and white patients with mTNBC, particularly for untreated patients. Effective treatment remains a substantial unmet need for all patients with mTNBC. In light of the lack of racial differences in this patient cohort, prospective studies are needed to further elucidate underlying biological differences that may have predictive or prognostic significance for AA patients with TNBC. Citation Format: Amie Tan, Vincent Shen, Luciana Preger, Bann-mo Day, Edith P. Mitchell. Assessing racial differences in patients with metastatic triple-negative breast cancer: Real-world evidence from US community oncology practices [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS7-53.

A study of 11th–15th centuries AD glass beads from Mambrui, Kenya: An archaeological and chemical approach

Twenty-three 11th–15th centuries AD glass beads collected from the archaeological site of Mambrui in Kenya were analysed using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). The results show that all of the glass samples are soda-alumina-silica glass. They belong to the mineral soda- alumina (m-Na-Al) glass type, characterised by high alumina and relatively low calcium and magnesia contents, that was widely distributed in eastern and southern Africa and southeast Asia in the 5th century BCE – 19th century CE. They were made with a mineral alkali flux called reh and sand. Comparison with contemporary m-Na-Al glass beads from Africa and southeast Asia shows that all of the Mambrui glass beads share similar characteristics to m-Na-Al 6 glass. This new glass type was recently identified by Dussubieux and Wood (2020) and is characterised by elevated levels of U (avg. 60 ppm) and Cs (~1.5 ppm). It is commonly found in eastern African sites such as Manda and Gede in Kenya. The lead isotope results suggest that the Mambrui glass beads might have been coloured using lead sources from four different sources including ores from India and northern Thailand.