Relative Sea-Level Change in the Northern Strait of Georgia, British Columbia

Twenty-four new radiocarbon dates from isolation basin cores, excavations and natural exposures, and an archeological site, constrain relative sea-level change since the last glaciation in the northern Strait of Georgia, British Columbia. Relative sea level fell rapidly from about 150 m elevation to 45 m elevation from 11 750 to 11 000 BP (13 750 to 13 000 cal BP), then its rate of fall slowed. The initial rapid emergence began soon after the transition from proximal to distal glaciomarine sedimentation, when the glacial front retreated from the Strait of Georgia and the Earth’s surface was unloaded. A sea-level lowstand a few metres below present-day sea level may have occurred in the early Holocene, but sea level was near its present level by 2000 BP. Sea-level change in the northern Strait of Georgia lagged the mid Strait of Georgia, 80 km to the south, by a few hundred years during initial emergence. The lowstand in the northern strait was later and probably shallower than in the mid strait. Isostatic depression inferred from the sea-level observations can be fit with two decaying exponential terms with characteristic decay times of 500 and 2600 years. The faster decay time corresponds to a shallow mantle viscosity of about 1019 Pa s, consistent with previous glacio-isostatic modelling. The present-day crustal uplift rate from the residual isostatic effects of the Cordilleran Ice Sheet is about 0.25 mm/a. Crustal uplift is not expected to significantly ameliorate projected sea-level rise in the mid and northern Strait of Georgia because present-day vertical crustal movements are inferred to be small.Vingt-quatre nouvelles dates au 14C provenant de carottes sédimentaires de bassins isolés, d’excavations, de coupes naturellement exposées et archéologiques permettent de cerner les changements du niveau marin relatif depuis la dernière glaciation dans la partie nord du détroit de Géorgie, en Colombie-Britannique. Le niveau marin relatif a rapidement passé de 150 m à 45 m d’altitude entre 11 750 et 11 000 ans BP (13 750-13 000 cal. BP), le taux d’abaissement ayant ralenti par la suite. L’émersion initiale rapide correspond à la fin de la sédimentation glaciomarine distale qui accompagnait le retrait du front glaciaire. Un bas niveau de quelques mètres sous le niveau actuel a pu s’instaurer durant l’Holocène inférieur, jusqu’en 2000 ans BP. Au début, le soulèvement isostatique a accusé un retard de quelques siècle sur celui de la zone du détroit à 80 km plus au sud. Le bas niveau de la partie nord du détroit est survenu plus tard et fut moins prononcé. Les données indiquent un enfoncement isostatique de type exponentiel avec des constantes de désintégration de 500 et de 2600 ans 14C. Le taux le plus rapide correspond à une viscosité du manteau terrestre d’environ 1019 Pa s, ce qui concorde avec les résultats de la modélisation glacio-isostatique. Le taux de soulèvement glacio-isostatique actuel résultant de l’inlandsis de la Cordillère s’établit à environ 0,25 mm/a. Ce taux ne peut contrer les effets du rehaussement du niveau marin prévu pour cette région en raison des faibles mouvements de la croûte terrestre qui y sont envisagés

Nanotools for Neuroscience and Brain Activity Mapping

Neuroscience is at a crossroads. Great effort is being invested into deciphering specific neural interactions and circuits. At the same time, there exist few general theories or principles that explain brain function. We attribute this disparity, in part, to limitations in current methodologies. Traditional neurophysiological approaches record the activities of one neuron or a few neurons at a time. Neurochemical approaches focus on single neurotransmitters. Yet, there is an increasing realization that neural circuits operate at emergent levels, where the interactions between hundreds or thousands of neurons, utilizing multiple chemical transmitters, generate functional states. Brains function at the nanoscale, so tools to study brains must ultimately operate at this scale, as well. Nanoscience and nanotechnology are poised to provide a rich toolkit of novel methods to explore brain function by enabling simultaneous measurement and manipulation of activity of thousands or even millions of neurons. We and others refer to this goal as the Brain Activity Mapping Project. In this Nano Focus, we discuss how recent developments in nanoscale analysis tools and in the design and synthesis of nanomaterials have generated optical, electrical, and chemical methods that can readily be adapted for use in neuroscience. These approaches represent exciting areas of technical development and research. Moreover, unique opportunities exist for nanoscientists, nanotechnologists, and other physical scientists and engineers to contribute to tackling the challenging problems involved in understanding the fundamentals of brain function

Coastal root garden cultivation on the Coast Salish: The case of Tl’chés, Songhees First Nation territory.

Coastal root gardens are areas of coastal marshland from which First Nations people on the Northwest Coast of North America traditionally cultivated gardens of Pacific silverweed and springbank clover. These plants, and the productive ecosystems they inhabit, were carefully managed through a variety of methods such as weeding, transplanting, and tending to the soil. Though these garden sites have been the subject of limited study on the central and northern coast of British Columbia, they remain under-represented in our understanding of traditional Coast Salish eco-cultural management practices. Furthermore, there has been no systematic study of the ecological and archaeological attributes that might differentiate a cultivated and managed area from unmanaged sites. Bridging this gap, we have identified a possible root garden on the archipelago of Tl’chés, off the southern tip of Vancouver Island. In partnership with the Songhees First Nation­, we combine archaeological, ecological and soil research to better understand this garden and its position within the larger Tl’ches biocultural landscape. The study of this site will expand understandings of Coast Salish cultivation practices and increase our ability to identify these fragile coastal sites in the absence of community or traditional knowledge, thereby promoting their re-integration within contemporary Indigenous restoration and management practices. Furthermore, by identifying archaeological and ecologically detectable attributes of coastal root gardens, we can further advocate for their protection under existing heritage legislation

Getting the youth back to the land: Community-based collaborative Archaeology at Tl’ches

Tl’ches is an island group in the Salish Sea near present-day Victoria. As Songhees Nation reserve land, it is an archetypal Cultural Keystone Place that has been inhabited by Lekwungen-speaking families for generations. Ongoing community-based archaeological and ethnoecology research regards this archipelago as an ecosystem shaped by millennia of indigenous resource management and subsistence practices. An ongoing collaborative research project is centred on the community value of “getting the youth back to the land,” and combining community knowledge and priorities with archaeological and historical ecology data and methods. Together we explore indigenous soils, blue camas and spring bank clover root gardens, and a complex of pre-contact and post-contact villages. Importantly, youth are increasingly involved in not just learning, but in contributing to research goals, methods, and practice. Tl’ches offers a complex and robust Lekwungen and environmental record—it is an eco-cultural legacy of sustainable Indigenous inhabitation and management. In effect, it is also simultaneously a place of co-discovery and shared knowledge production

Shifting Narratives, Recognizing Resilience: New Anti-Oppressive and Decolonial Approaches to Ethnobotanical Research with Indigenous Communities in Canada

Revitalizing Indigenous land-based practices are acts of resurgence and resistance. The presence of Indigenous bodies occupying land to nourish and strengthen themselves through ancestral practices is a political act. These cultural systems of knowledge and practice are in opposition to historical and ongoing colonial attempts to dispossess Indigenous Peoples of their connections to land. Indigenous People have undergone changes in diet and land access, including cultivating and harvesting plants for health and wellbeing. Recognizing and understanding the impacts and implications of colonization on land-based knowledge is fundamental in carrying out meaningful work within Indigenous communities in the field of ethnobotany. Much of the literature and media on Indigenous issues continue to uphold trauma narratives. When working with Indigenous communities on projects, it is essential to understand the history, impacts and ongoing struggles related to colonization and genocide in America in order to not cause harm and to contribute positively to those communities. Furthermore, by taking our responsibilities one step further, we can carry out research in trauma-informed ways while prioritizing anti-oppressive, decolonial and strength-based approaches to our research and collaborations with Indigenous communities. We illustrate these points through a community-based case study from the Squamish Nation in British Columbia, Canada.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Clam Terrace Rock Walls: The Ecology and Social Significance of Monumental Places

When we think of the monumental works of the indigenous peoples of the Northwest Coast, we typically think of long houses, canoes, and totem poles. But the First Peoples are also monumental movers of stone in the making of resource sites like clam terraces and root gardens. Clam terraces are special places that enhance beaches for clam production, and are used to harvest not only clams but an entire suite of algae and animals. While many studies have focused on the ability of clam gardens to enhance clam productivity, few have examined the role of the rock wall itself. These stories describe the monumental work of Indigenous peoples of the Northwest Coast to create these rock wall structures, indelibly shaping land and seascapes with their creation and inscribing the physical world with visible records of familial connections to places, while significantly managing food resources. In other words, the moving of stone at this monumental scale entangles the production of key foods with the making histories and places. These stories highlight the importance of these features in shaping our seascapes as well as our ecosystems. By creating new habitat, rock walls change intertidal ecological communities and alter the availability of non-clam food species, bringing foods like crab, urchin, seaweeds, and octopus into the garden and onto the plate

Using Situated Knowledge and Remote Sensing to Assess Climate Change Vulnerability for Coastal Ecosystems of High Cultural Importance

Joan Morris was born and raised at Tl’ches, an island group near present-day Victoria on southern Vancouver Island. Within the territory of the Songhees Coast Salish Nation, it is a Cultural Keystone Place permanently occupied by Lekwungen families for generations. The island is an ecosystem shaped by millennia of resource management and subsistence practices, including important resource sites such as camas (Camassia spp.) prairies, tidal marsh root beds, seabird nesting rocks, and clam beds. There are also many sites associated with the harvesting of crabs, sea urchins, marine algae (kelps and edible red laver seaweed) and fish (including rockfish and salmon). Within Joan’s life, tangible environmental changes have occurred at Tl’ches. In 1957, a drinking water shortage forced Joan and other residents to move to Vancouver Island. Invasive species have since taken root. Today, global climate change is threatening to further impact the island chain. To understand both the deep history of Lekwungen inhabitation, and their future use of Tl’ches, our approach is twofold. First, in collaboration with the Songhees Nation, we have been using drone photography to capture images of the coastline of Tl’ches as a first step to inventorying the archaeological and other surficial cultural features of this land- and seascape. The resulting imagery will also provide baseline visual data for the current coastline ecosystem, allowing comparisons to be made in the future about beach composition, size of kelp beds and eelgrass beds, and potential erosion of coastline and the infilling of lagoons. Second, we are using high precision Lidar and orthophotos to model near-future sea level, tidal heights, and extreme weather events associated with global climate change. To date, we have identified specific risks of erosion for key village sites as well as intertidal and near-shore habitats resulting from projected sea level change

46. Racial and Ethnic Disparities in COVID-19 Incidence among Persons with HIV in a Multisite-Cohort

Abstract: Background: Little is known about how race and ethnicity, imperfect (albeit accessible) proxies for structural racism, impact COVID-19 incidence among people with HIV (PWH). We report the cumulative incidence and incidence rate ratios (IRR) for COVID-19 in a long-term multi-site cohort of PWH across the US Figure 1. Cumulative incidence of COVID-19 in the CNICS cohort Methods: We examined COVID-19 cumulative incidence and IRR among PWH in care between 3/1/2020 and 12/31/2020 at seven sites in the CFAR Network of Integrated Clinical Systems (CNICS) cohort. We define COVID-19 incident case as having a laboratory-confirmed (RT-PCR/Ag) SARS-CoV-2 positive result or diagnosis verified by chart review. Reinfections were excluded. Results are presented as monthly and quarterly cumulative incidence and IRR with 95% CI stratified by CD4 count, self-reported race/ethnicity, and site. Follow-up was censored on the earliest of diagnosis of COVID-19 disease, loss to follow up, or 12/31/2020 Results: Among 15,780 PWH in care in the CNICS cohort during the study period, 62% were non-white, with a median (IQR) age of 52 (IQR 40-59), 95% were on antiretroviral therapy, 17% had a CD4 count less than 350, and 6% less than 200. Overall, 651 PWH tested positive for COVID-19 for a cumulative incidence of 4.13%. COVID-19 cumulative incidence increased from 0.77% at the end of the first quarter to 4.12% by the end of December 2020. At the peak of the pandemic in December 2020, the cumulative incidence in Black PWH was 1.68 fold higher than in white PWH (p=.033) and 2.35 fold higher in Hispanics than in whites (P< .0001), figure 1. Similarly, the IRR for COVID-19 was 1.71 (95% CI 1.42-2.07) for Black and 2.40 (95% CI 1.91-3.01) for Hispanic PWH relative to white. Although there was variation across sites, reflecting geographic differences in pandemic waves and access to COVID-19 testing, overall individual trends remained the same. COVID-19 cumulative incidence was similar across CD4 cell count strata Conclusion: Our results suggest effects of structural racial disparities on COVID-19 incidence in this diverse population of PWH across the US, with higher and disproportionate rates of COVID-19 in Black and Hispanic PWH. Incidence estimates are conservative because testing was not uniform, and no systematic testing was conducted Disclosures: Edward R. Cachay, MD, MAS, Gilead Science (Grant/Research Support, Advisor or Review Panel member)Merck Sharp & Dohme Corp (Grant/Research Support) Adrienne Shapiro, MD, PhD, Vir Biotechnology (Scientific Research Study Investigator) Darcy Wooten, MD, MS, Nothing to disclose Rachel A. Bender Ignacio, MD MPH, Abbvie (Individual(s) Involved: Self): Consultant; SeaGen (Individual(s) Involved: Self): Consultant Greer A. Burkholder, MD, MSPH, Eli Lilly (Grant/Research Support) Heidi Crane, MD, MPH, ViiV (Grant/Research Support