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Archaeological evidence indicates that Birnirk peoples (AD 650 – 1300) are the proposed genetic ancestors of the Thule Inuit (AD 950 – 1400) and are potentially an intermediary population between the Thule Inuit and earlier Old Bering Sea people (AD 1 – 1000). We sequenced the first hypervariable region of the mitochondrial DNA of 22 clearly associated Birnirk individuals from the Piġniq (Birnirk), Kugok, Kugusugaruk, and Nunavak sites on the North Slope of Alaska. Haplotypes A2a, A2a1, A2a3, A2b1, and D4b1a2a1a were identified in this population, demonstrating an expansion of Birnirk maternal genetic diversity. Maternal lineages from these individuals were evaluated with other past and contemporary Inuit populations from the Chukotka Peninsula to eastern Greenland. Our findings confirm Birnirk Inuit as probable maternal ancestors to Thule Inuit and may be among the first peoples possessing these lineages to have moved into the western North American Arctic from the Bering Strait region.

Along the coasts of northern Alaska, in a treeless tundra environment, the primary wood resource for coastal populations is driftwood, a seasonal and exogenous resource carried by the major rivers of western North America. The potential of Alaskan coastal archaeological wood for tree-ring research was first assessed in the 1940s by archaeologist and tree-ring research pioneer J. L. Giddings. Despite his success, the difficulties of dendrochronological studies on driftwood and the development of radiocarbon dating during the 1950s resulted in the near-abandonment of dendrochronology to precisely date archaeological sites and build long sequences using archaeological wood in Alaska. In this study, we explored the possibilities and limitations of standard ring-width dendrochronological methods for dating Alaskan coastal archaeological wood. We focus on the site of Pingusugruk, a late Thule site (15th–17th CE) located at Point Franklin, northern Alaska. The preliminary results have been obtained from the standard dendrochronological analyses of 40 timber cross-sections from two semi-subterranean houses at Pingusugruk. We cross-correlated individual ring-width series and built floating chronologies between houses before cross-dating them with existing regional 1000-year-long master chronologies from the Kobuk and Mackenzie rivers (available on the International Tree-Ring Databank, ITRDB). Additional work on various dendro-archaeological collections using an interdisciplinary approach (geochemical analyses of oxygen isotopes and radiocarbon dating) will help develop and expand regional tree-ring chronologies and climatic tree-ring sequences in Alaska.

We explore marine reservoir effects (MREs) in seal bones from the northern Bering and Chukchi Seas regions. Ringed and bearded seals have served as dietary staples in human populations along the coasts of Arctic northeast Asia and North America for several millennia. Radiocarbon (14C) dates on seal bones and terrestrial materials (caribou, plants seeds, wood, and wood charcoal) were compared from archaeological sites in the Bering Strait region of northwestern Alaska to assess MREs in these sea mammals over time. We also compared these results to 14C dates on modern seal specimens collected in AD 1932 and 1946 from the Bering Sea region. Our paired archaeological samples were recovered from late Holocene archaeological features, including floors from dwellings and cache pits, that date between 1600 and 130 cal BP. 14C dates on seal bones from the northern Bering and Chukchi Seas show differences [R(t)] of 800 ± 140 years from to their terrestrial counterparts, and deviations of 404 ± 112 years (ΔR) from the marine calibration curve.

Beach ridges and spits along the north-facing coast of the Chukchi Sea record paleo-storm history during the 1st millennium AD, correlative with a widespread global cooling climate episode. Northwest Alaska is a sensitive proxy owing to its absence of tectonism, glacio-isostasy, and a low rate of eustatic sea level rise. Four locales provide a regional transect and detailed chronologies: north-facing Deering and Cape Espenberg and west-facing Kotzebue and southwest facing Point Barrow. A single storm or series of storms during AD 400–600 impacted both north and south areas, while lesser intensity storms occurred across the southern region during the 11th century AD. The first millennium AD storms were as strong as or stronger than those of the 20th century, if paleo-sea level is factored in. Storm-heightened upwelling had a salubrious effect on cultures around the Chukchi Sea, leading to a florescence of whaling and walrusing.

Magnetic survey methods have recently shown tremendous potential for the detection of archaeological hearths in Eastern Beringia, ranging from intermittent open-air camp fires to larger heat intensive activity areas. Here we present an overview of the method along with eight supporting case studies from seven U.S. National Park Service units in the U.S. state of Alaska, covering diverse geographic settings and time-periods. Together, these case studies demonstrate the capabilities of magnetic detection instruments in various modes of operation for finding datable archaeological deposits that span the breadth of known human occupation of this region. The examples range from the simplest use of the magnetometer as a single sensor reconnaissance instrument in a “search mode”, to use as a gradiometer in conjunction with other geophysical methods such as ground-penetrating radar, to record precise measurements and inform nuanced interpretations. Examples presented here range from the terminal Pleistocene to historic periods, spanning 12,000 years of human activity in Eastern Beringia, and encompassing the arrival, emergence, and expansion of multiple human groups or cultural traditions in the New World.

The central problem we investigate is how coastal communities in the Arctic can plan for future storms in the absence of continuous, long-term data and/or instrumentation to monitor climatic events. The native village of Shaktoolik, Alaska recognizes these limitations and seeks increased monitoring of life-threatening storms affecting their village in their adaptation planning documents. To address this situation, and with the consent of the Tribal Council, we establish a baseline to monitor storm intensity in this data-poor region by dating and mapping storm surges in the Shaktoolik area. A storm surge is a proxy of storm intensity. We use driftwood in two ways to reconstruct past storm surges. First, we plot GPS points of driftwood lines on remote sensing imagery and digital elevation model data to map the maximum extent of storm surge for the November 2011 and 2013, and August 2019 storms. Second, in order to demonstrate that a particular log could have been deposited by those storms, dendrochronological analysis of individual logs within those deposits provides an estimate of when those trees died and could have entered the water as driftwood. These techniques, however, cannot determine the date of when those logs were deposited on a given beach. To narrow the date of the driftwood deposits from past storms, that is, to determine when the driftwood landed on the beach, local knowledge and observations are coupled with newspaper accounts. From these three lines of evidence, we show that the maximum storm surge the village can withstand without inundation is equivalent to the 2011 and 2019 storms. Those storms can be used as baseline indicators for future storms. This method of monitoring storm surges can be scaled up to other locations that also have minimal storm monitoring infrastructure.

Prehistoric fuel management and hearth functions are key research issues that have benefitted from the development of experimental and ethnoarchaeogical approaches aimed at providing interpretative models for archaeological fire and fuel studies.In this paper, we present a selection of ethnographic, ethnoarchaeological and ethnohistorical data mostly collected among Evenks and Athabascans of East Siberia and North America. Our aim is to question and discuss the relationship between fuel and hearth functions from an ethnoarchaeobotanical perspective: what are the criteria for selecting plant fuels? How archaeologically visible can these diverse fuel types be and what do they tell us about past fire-related activities?Our data shows that the contents of combustion structures result from multiple people-environment interactions at different levels, few of which are accessible to the archaeologist. Nevertheless, ethnoarchaeology, by fostering a reflection on taphonomy issues in the broad sense, active...

International audience

Remains of animal fuel and driftwood fires are evident in Birnirk and Thule sites of northwestern Alaska (AD 11th-14th century). To better understand these fires, a robust experimental protocol was designed to study the effects of multi-fuel fires, in particular, the addition of fat to woody fuels. In Arctic regions, permafrost and climate conditions do not allow for the development of tree vegetation. Marine mammal oil and bones served as fuel substitutes, as did locally shrubby vegetation and driftwood accumulations. The excavation of numerous thick burnt areas in many Arctic sites confirms the use of multiple fuels including wood, animal fat, and bone in large quantities. These burnt areas correspond to a wide range of fire activities—cooking, smoking, firing ceramics, and others—but the actions and effects of each fuel are still poorly known. We describe conditions necessary to achieve a reproducible and statistically representative experimental fire sample. We compared fuel combinations of driftwood or non-drifted wood, animal fat, and caribou bones over 55 combustions. Experiments were conducted under controlled conditions in a laboratory in France and on the coast of northwestern Alaska. We found that a minimum of 30 test assays was needed to obtain statistically significant results but many research avenues can be obtained from smaller series. We obtained key figures and descriptive data on the impact of different animal fuels on fire temperature and duration, as well as on the firewood spectrum, with important implications for the representation of different woody fuels and the fragmentation patterns of charcoals. We report a relatively rapid rate of formation for blackened and crusted sediments when seal oil is burned along with driftwood. This means that thick accumulations of burnt material may not be a reliable signal of long-term occupations and that the relationship between the duration of site occupation and fuel management deserves further study.

Activities and production among Inupiaq peoples were primarily divided by gender. This gendered division of labor also extended to a spatial segregated pattern of the household in some Arctic cultures, while others had a gender-integrated spatial pattern. There are very few archaeological studies of gender, or studies of gendered space, in the Arctic. We study gendered use of space in pre-colonial Northwest Alaska through a spatial analysis of ceramic, and other gendered artifact, distributions in Thule-era houses from Cape Espenberg, Alaska. We used the HDBSCAN (Hierarchical Density Based Spatial Clustering of Applications with Noise) algorithm in Python to analyze and compare distributions of gendered artifacts. We found no clear evidence for gender-segregated use of space, or for specific activity areas. This does not mean that gender-segregated use of space or activity areas did not exist, we simply found little evidence supporting these practices due, at least in part, to issues of sample size, house size, and the role of secondary and post-deposition processes in shaping the ceramic assemblage and distribution. Our analysis identified several interesting patterns of behavior, particularly related to site-formation processes. Further, this study illustrates the potential of Python for conducting archaeological spatial analysis.

International audience; In northwestern Alaska, burned activity areas with horizons of carbonized organic remains and sand layers cemented with sea mammal fat are often found outside of Birnirk and Thule semi-subterranean house features. In this paper, we address the question of using animal products (such as terrestrial and marine mammal fat, and bones) as supplementary fuels in wood-poor environments by reporting on a series of sixty-four experimental combustions under controlled conditions. Results assess the impact of animal fuels on wood fire temperature and duration as well as identify the effect of adding bones and fat to fires on archaeological charcoal remains. These results provide a framework to discuss why, when and for what purpose Birnirk and Thule people used fires in northwestern Alaska.

[eng] Glycogen is a branched polysaccharide that serves as an intracellular store of glucose that can be mobilized to maintain homeostasis or to fuel cellular processes. Glycogen is synthesized by glycogen synthase, which is present in two different isoforms: liver glycogen synthase (LGS) is mainly expressed in the liver, while muscle glycogen synthase (MGS) is expressed everywhere else. Recent studies are starting to uncover new roles for glycogen besides just being a glucose depot. Importantly, glycogen metabolism has been implicated in the normal aging process in species ranging from Saccharomyces cerevisiae to humans. However, the implication of glycogen in senescence, a hallmark of aging, is less well understood. Senescence is a tumor suppressive response that results in an irreversible cell cycle arrest, and can be induced by a variety of cellular stressors. Glycogen has previously been shown to accumulate in the context of senescence, however the significance of this remains unclear. Taking this into account, we aim to elucidate the role of glycogen in proliferation specifically in the context of aging, tumorigenesis and hepatic regeneration. To achieve this, we used two knock-out (KO) models where glycogen synthesis is disrupted: 1) mouse embryonic fibroblasts (MEFs) isolated from MGS KO embryos and, 2) LGS KO mice which lack hepatic glycogen. These two models allowed us to test what occurs in proliferative contexts when glycogen is absent both in vitro and in vivo. First, we subjected WT MEFs to replicative senescence (RS), where MEFs were passaged every time the plate reached confluence, until cells entered a growth arrested state (senescence). We determined that glycogen accumulates, and further observed that MGS is activated during senescence. To test whether the presence of glycogen affects the senescent response, we subjected glycogen-free MEFs to RS, and observed that they exhibit various markers of senescence: flattened cell morphology, positive senescence- associated B-gal staining, and an increased expression of senescence protein markers. Interestingly, MGS KO MEF overcome the senescent phase faster than WTs by becoming immortalized at an earlier time point. After transcriptomic analysis, we determined that MGS WT MEFs show an enrichment of the TGF-b pathway during senescence, while MGS KO MEFs are depleted. Furthermore, we found that the transcriptional signatures of senescent MGS KO MEFs are transcriptionally more similar to actively proliferating cells than to senescent WT MEFs. These results suggest that in the absence of glycogen, MEFs enter a pseudo-senescent state allowing them to immortalize faster than wild type counterparts. Once immortalized, MGS KO MEFs continue exhibiting a proliferative advantage over wild types, in addition to increased migratory and clonogenic capacities. Furthermore, we tested the metabolic consequence of removing glycogen by performing live cell analysis, which reveals a metabolic shift towards glycolysis. These results bring the Warburg effect to mind, suggesting that glycogen-free cells reprogram their metabolism to satisfy their energetic needs. Lastly, we question whether glycogen is important in proliferative contexts in vivo. For this, we used LGS KO mice and subjected them to two hepatic proliferative challenges: hepatic regeneration through partial hepatectomy (Phx) and hepatocellular carcinoma (HCC) induction. After Phx, we showed that there is a higher proportion of LGS KO hepatocytes in the S phase of the cell cycle which suggests that glycogen is an important regulator of hepatocytic proliferation. In the pathological proliferative context of N-nitrosodiethylamine (DEN), we showed that LGS KO mice present higher mortality and tumor burden than controls. Therefore, our results suggest that glycogen is playing a protective role in animals exposed to DEN. In conclusion, our results indicate that glycogen is an important modulator in the context of cellular proliferation and aging, and positions this polysaccharide as a novel target for therapeutic interventions to combat aging and possibly, cancer.

International audience; During a 9-week field season in 2016 at Cape Espenberg, excavations of two driftwood houses including one with human remains were conducted in collaboration with Shishmaref community representatives. Implementation of field conservation procedures helped stabilize organic artifacts upon excavation, while experiments with seal oil and wood-fed fires tested hypotheses on fuel use and hearth function. Past landscapes were investigated by refining the local sea level change chronology to define beach ridge stabilization. Interviews with Shishmaref community members focused on the old objects people collect and a community workshop was conducted in Shishmaref to discuss the project’s summer discoveries.

This paper describes and interprets a well-preserved early Thule semi-subterranean dwelling from Cape Espenberg, Alaska. The house architecture is similar in many respects to other early Thule dwellings with a sub-rectangular main room, long sunken entrance tunnel, and associated kitchen area. However, the presence of narrow side benches and associated flooring differences adds significantly to the variability present in Thule house form. Radiocarbon dates indicate occupations spanning 1300 to 1450 cal CE. Wood analysis suggests that the house underwent at least one rebuilding episode, which seems to have extended the house occupation into the early 15th century. People acquired mostly small seals for their subsistence, but supplemented their diets in the spring and fall with migrating birds, fish, terrestrial mammals, and other marine mammals. This house represents a fairly typical early Thule coastal winter occupation, but careful excavation of a well-preserved house reveals interesting details in house form, wood use, and subsistence patterns.

Les sites archéologiques du cap Espenberg sur la côte nord-ouest de l’Alaska (fig. 1) conservent les maisons d’hiver des Thuléens, une culture archéologique directement ancestrale de celle des Inuit de l’Arctique nord-américain. Ces habitations ont pour particularité d’être principalement construites en bois puis recouvertes de tourbe. Par ailleurs, le bois est omniprésent dans les ensembles archéologiques de l’Arctique occidental, au point que le Thuléen est souvent considéré comme une « cul...

Ground-penetrating radar (GPR) offers many advantages for assessing archaeological potential in frozen and partially frozen contexts in high latitude and alpine regions. These settings pose several challenges for GPR, including extreme velocity changes at the interface of frozen and active layers, cryogenic patterns resulting in anomalies that can easily be mistaken for cultural features, and the difficulty in accessing sites and deploying equipment in remote settings. In this study we discuss some of these challenges while highlighting the potential for this method by describing recent successful investigations with GPR in the region. We draw on cases from Bering Land Bridge National Preserve, Cape Krusenstern National Monument, Kobuk Valley National Park, and Gates of the Arctic National Park and Preserve. The sites required small aircraft accessibility with light equipment loads and minimal personnel. The substrates we investigate include coastal saturated active layer over permafrost, interior well-drained active layer over permafrost, a frozen thermo-karst lake, and an alpine ice patch. These examples demonstrate that GPR is effective at mapping semi-subterranean house remains in several contexts, including houses with no surface manifestation. GPR is also shown to be effective at mapping anomalies from the skeletal remains of a late Pleistocene mammoth frozen in ice. The potential for using GPR in ice and snow patch archaeology, an area of increasing interest with global environmental change exposing new material each year, is also demonstrated.

This chapter presents the availability of wood in different subregions of Arctic North America and discusses its use and importance through time and across space in Arctic human settlements. The main wood resource available along the treeless Arctic coast was driftwood, a resource for which availability varied with climate and environmental conditions. Detailed data on early wood used as fuel are scant, but remains are known as early as the first settlement of Alaska. For some archaeologists, availability of wood as fuel is tightly linked to the early colonization of Eastern Beringia at the end of the Pleistocene. In later cultural developments, abundant wood remains show the resource as critical for architecture and small carpentry. Hunting and transport required wood constructions, making wood a valuable commodity. Arctic permafrost leads to remarkable preservation, providing the opportunity to analyze and better understand wood technology and use even in the most remote areas.

Global vegetation models predict that boreal forests are particularly sensitive to a biome shift during the 21st century. This shift would manifest itself first at the biome!s margins, with evergreen forest expanding into current tundra while being replaced by grasslands or temperate forest at the biome!s southern edge. We evaluated changes in forest productivity since 1982 across boreal Alaska by linking satellite estimates of primary productivity and a large tree-ring data set. Trends in both records show consistent growth increases at the boreal‐tundra ecotones that contrast with drought-induced productivity declines throughout interior Alaska. These patterns support the hypothesized effects of an initiating biome shift. Ultimately, tree dispersal rates, habitat availability and the rate of future climate change, and how it changes disturbance regimes, are expected to determine where the boreal biome will undergo a gradual geographic range shift, and where a more rapid decline.

International audience; "Since the mid 1970s, Interior Alaska white spruce trees experienced markedly lower growth than during the 19th and early 20th centuries. This observation raises the question of forest persistence on certain sites of lowland central and eastern Alaska. We analyzed white spruce growth across a 36-site network (540 trees) on three major river floodplains in boreal Alaska along a longitudinal gradient from eastern Interior to the southwest tree limit to test for the presence of tree growth patterns and climate sensitivities. Chronologies are compared for temperature sensitivity at both stand and individual tree levels, using data from Bethel, McGrath, and Fairbanks NWS stations during the common period of 1952–2001. Cross-dated stand-level ring width chronologies indicate three regions of common signal in tree growth across the gradient. Temperature sensitivity of stand- and individual-tree chronologies is spatially coherent. Most downriver chronologies correlate positively with spring mean monthly temperatures (MMT) at Bethel, mid- and upriver chronologies correlate negatively with MMT of May and previous year July at either McGrath or Fairbanks, and an area in between is a mixed population of positive and negative responders. In downriver positive responders, recent increases from suboptimal cool temperatures accelerated tree growth, while in mid- and upriver negative responders, recent increases from optimal or above-optimal temperatures decreased growth. Fairbanks negative responders are also negatively correlated with a 200-yr index of recorded and reconstructed Fairbanks summer temperatures, and recent sustained record high summer temperatures are associated with the lowest relative growth. Until the 1940s, absolute growth rate of negative responders was greater than positive responders, but from the 1970s the positive responders grew more. These results explain why northern ring width samples can display opposite temperature sensitivity and contribute to understanding recent “divergence” or loss of temperature sensitivity in a changing climate. We find that July MMT and annual precipitation at Fairbanks are now outside the limits that previously characterized the North American distribution of white spruce, and are near the reported physiological limits of the species. Our results of the spatial and temporal change of white spruce temperature sensitivity provide strong empirical evidence of previously proposed early stage biome shift in boreal Alaska due to clear climatic causes. Already, western Alaska, previously extending to tree limit, has become the optimum climate region for the species. With modest additional warming widespread tree death will be unavoidable on warmer lowland interior sites, where persistence of white spruce is unlikely. " (source éditeur)

Until the introduction of commercial wood, driftwood was the main wood resource for people along the coasts of northern North America and Siberia. In Arctic archaeological sites and particularly in the last 2,000 years deposits, wood remains are often well preserved and provide archaeologists with large and representative samples of what was used at a site. However these remains have not been analyzed in great detail despite the interest of studying the use of wood in regions lacking trees. This paper discusses the importance of recording systematic and precise data on driftwood accumulations and wood use in order to better understand: 1) the formation of wooden assemblages, 2) driftwood availability at the time the site was occupied, and 3) users’ selection choices. A survey of modern driftwood accumulations, distribution, Availability and composition in Bering Strait and southern Chukchi Peninsula is also presented. It draws on the study of archaeological collections of Alaskan sites dated to the 6th century and the 11th-15th centuries A.D. to show how establishing such data bases should, in the long run, improve the chronological, technical or even social interpretation of wood remains from arctic sites., Jusqu’à la vente de bois commerciaux venus du sud, les populations installées le long des côtes des régions septentrionales d’Amérique du Nord et de Sibérie allaient régulièrement sur les plages s’approvisionner en bois flottés, principale source de ligneux dans ces régions dénuées d’arbres. Dans les sites archéologiques arctiques et particulièrement dans les dépôts des 2 000 dernières années, la conservation des vestiges en bois est souvent remarquable et fournit aux archéologues des assemblages numériquement représentatifs. Pourtant, ces vestiges ont rarement fait l’objet d’études approfondies malgré l’intérêt d’étudier l’exploitation d’une telle ressource dans des régions qui ne la produisent pas. Cet article discute de la nécessité de connaître la nature des accumulations de bois flotté (modalités de formation des dépôts naturels, propriétés des matériaux disponibles, etc.) afin de mieux comprendre: 1) la formation des assemblages archéologiques en bois, 2) la disponibilité des bois d’oeuvre à l’époque d’occupation du site, et 3) les variables de la sélection des bois par les occupants des sites. L'article présente aussi les résultats d’un premier inventaire de la disponibilité et de la composition actuelle des amas naturels de bois flotté dans le détroit de Béring et dans le sud de la péninsule des Tchouktches. Il s’appuie sur l’étude de collections archéologiques de sites alaskiens datés du 6e et du 11e-15e siècles ap. J.-C. pour montrer comment l’établissement de tels référentiels sur les bois flottés devrait à long terme améliorer l’interprétation chronologique, technique, voire sociale, des vestiges en bois des sites de l’Arctique.

Le cap Espenberg est une flèche littorale au large de la mer des Tchouktches dans le nord-ouest de l’Alaska contenant les vestiges de 4000 ans d’occupations humaines et de changements climatiques. Les recherches archéologiques et paléo-environnementales, menées depuis 2009 dans le cadre d’un projet pluridisciplinaire, apportent des informations nouvelles sur la chronologie des occupations du dernier millénaire et documentent l’émergence de la culture thuléenne directement antérieure et ancestrale aux Inuit/Inupiat d’aujourd’hui, dans un contexte d’intensification des conditions cycloniques, contemporain du petit âge glaciaire. Parallèlement, ces recherches posent la question de la nature de l’occupation Birnirk nouvellement identifiée sur le cordon E-6 peu élevé, site KTZ-304, une formation archéologique qui contribue à l’émergence du Thulé entre le xiie et le xiiie siècles apr. J-C. Ce monticule birnirk présente de fortes ressemblances avec le site éponyme situé au nord de l’Alaska (région de Barrow). Les fouilles de l’habitation F12 ont révélé une structure aux pièces multiples avec une superposition de phases d’occupation et un assemblage de vestiges montrant de vraies différences architecturales, les signes d’une circulation des matériaux et des objets sur de grandes distances et des indices de mobilité. Tous ces éléments suggèrent l’arrivée de groupes originaires de Chukotka et relancent l’ancienne controverse de l’archéologie arctique de l’origine du Birnirk sur le littoral alaskien. Cape Espenberg is a sandy spit on the Chukchi Sea coast in northwestern Alaska, containing the remains of 4000 years of human occupation and climatic change. Archaeological and paleo-ecological research since 2009 as part of a large pluridisciplinary project provides new data on settlement chronology for the last thousand year of occupation and documents the emergence of the Thule culture which is directly ancestral to today’s Inuit/Inupiat in a context of increased storminess during the Little Ice Age. At the same time, this research raises the question of the nature of the Birnirk occupation identified on the low E-6 dune ridge, site KTZ-304, an archaeological complex which contributes to the emergence of the Thule culture between the 12th and 13th AD. This Birnirk mound at Cape Espenberg resembles in many aspects the type side named Birnirk in north Alaska (Barrow region). The excavation of house F12 uncovered a multi-room structure with overlain occupation levels and produced a collection of remains showing real architectural differences, signs of long distance raw material and object circulation and of mobility. All these elements suggest newcomers possibly of Chukotka origin and provides the opportunity to revisit an old research question in Arctic archaeology, that of the origin of Birnirk culture on the Alaska coast.

In Arctic North America, Thule archaeological sites yield many wooden artifacts. The point in studying the sources of supply, the uses and the working processes of this raw material, is to add to our information on the Thule culture ; this purpose requires a methodology that takes into account both environmental characteristics and the chrono-cultural context. In a tundra ecosystem, the main wood source is driftwood which ice and surface currents in the Arctic Ocean carry from the boreal forest to arctic coasts. Wood identifications of some archaeological artifacts permit a discussion of the adequacy of the results on the basis of the known driftwood distribution data on arctic coasts. Some wood species served as «exchange markers» through the Arctic., Dans l'Arctique nord-américain, les sites archéologiques thuléens livrent une large quantité d'artefacts en bois. L'intérêt d'une étude de cette matière ligneuse axée sur sa provenance, ses usages et sa mise en oeuvre, est d'enrichir notre documentation sur la culture de Thulé ; cette finalité requiert une méthodologie adaptée aux particularités du milieu arctique et au contexte chronoculturel. Dans un environnement de toundra, le bois flotté est la première source de bois qui, depuis la forêt boréale, dérive jusque sur les côtes de l'Arctique. Sur la base de ce que l'on sait de la distribution et de la composition des amas naturels de bois flottés, l'examen xylologique d'objets archéologiques thuléens permet de discuter de la cohérence des résultats obtenus et d'envisager la présence de taxons, «marqueurs d'échanges» à travers l'Arctique., Alix Claire. Provenances et circulation des bois en milieu arctique : quels choix pour les Thuléens ?. In: Revue d'Archéométrie, n°22, 1998. pp. 11-22.

Sur la toundra côtière de l’Alaska et de l’Arctique, les Inuit comme leurs ancêtres ont surtout exploité des bois venus d’ailleurs, ceux que les vents et les flots ont apportés, reliant ainsi les forêts intérieurs aux côtes du nord. Cet article décrit un programme de recherche archéologique qui a établi un cadre méthodologique et développent des référentiels pour l’analyse des nombreux vestiges ligneux remarquablement conservés dans les sites des deux premiers millénaires ap. J.-C. dans le détroit de Béring. Il montre qu’un regard global sur la question du bois et de ses usages en contexte arctique est ce qui permet de faire parler les vestiges. On the tundra of Alaska and the Arctic coast, Inuit people, like their ancestors, used mostly woods coming from afar, carried by wind and currents linking the inland forests to the northern coasts. This article describes an archaeological research program that includes a methodological framework and is building data sets for analyzing the numerous and remarkable wooden remains preserved in Bering Strait sites of the last two millennia AD. It shows that a holistic approach to the question of wood and its uses in arctic contexts can allow us to prise out otherwise obscured meaning out of these remains.

Discussions of the development of past hunting equipment generally focus on lithic and bone projectile points and foreshafts, as these are often the only elements remaining in archaeological sites. In the last 15 years, the archaeology of alpine ice patches has provided a unique opportunity to analyze hunting equipment over time and gain knowledge of the wooden elements on which the points are hafted. This paper describes the wood and morphometrical analysis of a collection of 27 arrow shafts from two ice patch regions of the western Canadian Subarctic. In both regions, two main categories of arrow shafts show the selection of specific pieces of wood, spruce ( Picea sp.) on the one hand and birch ( Betula sp.) on the other, with associated morphometrical characteristics. These shafts also share some characteristics that are distinct from those of Arctic and coastal arrow shafts. Shafts of pine ( Pinus sp. sec. ponderosa ) and hemlock ( Tsuga sp.) were also identified in the southwestern Yukon Territory. The absence of correlation between the arrow shaft types and 14C dating raises the question of the significance of the arrow types and the potential for function, trade, or travel to explain the variation.

Background Polycystic Ovary Syndrome (PCOS) is an endocrine-metabolic disorder commonly associated with insulin resistance (IR). Previous studies indicate about the expression of molecules involved in the insulin pathway in endometria of women with PCOS-IR. Therefore, the aim of the present study was to evaluate the effect of insulin and testosterone in the expression of these proteins in the endometria and immortal endometrial stromal cell line (T-HESCs). Methods We examined the protein levels of Munc18c, PKC zeta, phospho-PKC Zeta, and Syntaxin-4. Protein levels were assessed by Western Blot and/or immunohistochemistry in proliferative endometria (NPE = 6) and in PCOS endometria with insulin resistance (PCOSE-IR = 6). We also evaluated whether high concentrations of insulin (100 nM) and/or testosterone (100 nM), during a 24 h stimulatory period, affected the expression of these proteins in an immortal endometrial stromal cell line (T-HESCs). Once stimulated, proteins were extracted from cells and were assessed by Western Blot analysis. Immunocytochemistry was performed to detect AR in T-HESC cells. Results Western Blot data showed decreased expression (p < 0,05) of Munc18c and phospho-PKC Zeta in PCOS-IR endometria (PCOSE-IR) with respect to the control (NPE). In the in vitro study, Western Blot analysis showed decreased levels of Munc18c, PKC Zeta and phospho-PKC Zeta with the different hormonal treatments when compared to the control condition (no hormonal stimulation) (p < 0,05). The AR was present in the endometrial stromal cell line (T-HESC). Conclusion The conditions of hyperinsulinism and hyperandrogenism present in PCOS-IR patients modulate the expression and/or phosphorylation of the proteins involved in the insulin pathway at the endometrial level. These data extend to the T-HESCs cells results, where insulin and testosterone exert an effect on both the expression and phosphorylation of proteins present in the pathway.

Ugiuvak, or King Island, off the coast of the Seward Peninsula in the Bering Strait, is among the few Arctic villages with stilt houses in an environment where wood is essentially lacking. In 1899, Edward W. Nelson, describing the island’s architecture, noted that wood was abundant. Today, the contrast is striking between the bareness and steepness of the coast and the extensive use of wood in the village. This article presents information about wood procurement and use as building material on Ugiuvak in the last 300 years based on literature review, on-site observations, and discussions with members of the King Island community. It briefly reviews the origin, circulation, and deposition of driftwood in the Bering Strait region. It then explores the possibility of a relationship in the 19th century between an increase in driftwood availability and the development of stilt architecture on the island, taking into account other wood sources that became available at the time. The last 150 years of occupation of the village were marked by a transition from a solely driftwood-based economy to one where driftwood was first supplemented and then largely replaced by lumber., Ugiuvak, ou île de King, au large du littoral de la péninsule Seward dans le détroit de Béring, fait partie des quelques rares villages arctiques à avoir des maisons sur pilotis dans un environnement où le bois est essentiellement absent. En 1899, Edward W. Nelson, dans sa description de l’architecture de l’île, observe que le bois y est abondant. Aujourd’hui, le contraste est frappant entre l’aspect dénudé des côtes abruptes et l’utilisation abondante du bois dans le village. Cet article présente des informations sur l’acquisition et l’utilisation du bois comme matériau de construction à Ugiuvak au cours des 300 dernières années sur la base de ce qui existe dans la littérature, d’observations faites sur l’île et de discussions avec des membres de la communauté de l’île de King. Il comprend un bref exposé sur l’origine, la circulation et le dépôt des bois flottés dans le détroit de Béring. Il explore ensuite la possibilité d’un lien entre une plus grande disponibilité du bois flotté au XIXe siècle et le développement de l’architecture sur pilotis dans l’île, tout en tenant compte des autres sources de bois qui deviennent disponibles à cette époque. Les derniers 150 ans d’occupation du village sont marqués par le passage d’une économie essentiellement fondée sur le bois flotté à une économie où le bois flotté a d’abord été complété par des bois commerciaux avant que ces derniers ne deviennent la première source d’approvisionnement.

International audience; The NWT Ice Patch Study was developed in partnership with the Shúhtagot’ine residents of Tulita, Northwest Territories, Canada. This paper explores how Shúhtagot’ine traditional knowledge, collected through the direct participation of Elders in our archaeological fieldwork, science camps with Elders and youth, Elder interviews, and traditional land-use mapping, is informing our interpretation of archaeological data collected at alpine ice patches in the Selwyn Mountains. While knowledge of bow-and-arrow and snare technologies persists in Shúhtagot’ine culture, Shúhtagot’ine oral history does not contain detailed knowledge of throwing dart technology. Using data collected in our traditional land-use mapping project, we consider the role of ice patches in the broader context of Shúhtagot’ine land use. We propose that resource harvesting on high alpine plateaus and adjacent ice patches in the summer was more important in late precontact times than it was after contact. Shúhtagot’ine land-use practices involve long-distance travel in all seasons. Safe travel in the alpine landscape requires detailed knowledge of environmental conditions, such as snow and ice conditions, and respectful engagement with the spiritual entities inhabiting the landscape; L’étude des névés des Territoires du Nord-Ouest a été réalisée en collaboration avec les Shúhtagot’ine de Tulita, dans les Territoires du Nord-Ouest, au Canada. Le présent article explore comment le savoir traditionnel des Shúhtagot’ine, recueilli lors de la participation directe des aînés à nos fouilles archéologiques, à des camps de sciences où aînés et plus jeunes participaient, à des entrevues avec les aînés et au relevé cartographique de l’utilisation traditionnelle des terres influence et éclaire notre interprétation des données archéologiques recueillies dans les névés alpins de la chaîne de Selwyn. Bien que le savoir relatif aux techniques de l’arc et de la flèche et de la chasse au collet est encore bien présent dans la culture des Shúhtagot’ine, leur histoire orale ne fait aucune allusion à la technique du tir au propulseur. En nous appuyant sur lesdonnées recueillies dans le cadre de notre projet de cartographie de l’utilisation traditionnelle des terres, nous considérons le rôle des névés dans le plus contexte plus large de l’utilisation du territoire par les Shúhtagot’ine. Nous proposons que la récolte estivale des ressources sur les hauts plateaux alpins et les névés adjacents était plus importante à la période juste avant le contact qu’à celle qui a suivi. Les pratiques d’utilisation des terres par les Shúhtagot’ine impliquent des déplacements sur de longues distances à toutes saisons. La sûreté des déplacements en milieu alpin nécessite une connaissance détaillée des conditions environnementales, telles que l’état de la neige et de la glace, de même qu’une interaction respectueuse avec les entités spirituelles qui habitent le milieu.

Global vegetation models predict that boreal forests are particularly sensitive to a biome shift during the 21st century. This shift would manifest itself first at the biome's margins, with evergreen forest expanding into current tundra while being replaced by grasslands or temperate forest at the biome's southern edge. We evaluated changes in forest productivity since 1982 across boreal Alaska by linking satellite estimates of primary productivity and a large tree-ring data set. Trends in both records show consistent growth increases at the boreal-tundra ecotones that contrast with drought-induced productivity declines throughout interior Alaska. These patterns support the hypothesized effects of an initiating biome shift. Ultimately, tree dispersal rates, habitat availability and the rate of future climate change, and how it changes disturbance regimes, are expected to determine where the boreal biome will undergo a gradual geographic range shift, and where a more rapid decline.

Cet article s’intéresse aux destins parallèles de deux collections unangax̂ (aléoutes) constituées dans la seconde moitié du XIXe siècle par le Français Alphonse Pinart et l’Américain William Dall. Fondées sur une rivalité entre ces deux personnages, ces collections, issues de leurs explorations respectives de cavernes funéraires de l’île d’Unga, forment un ensemble d’objets aussi unique qu’énigmatique, divisé entre le Château-Musée de Boulogne-sur-Mer (France) et le National Museum of Natural History de la Smithsonian Institution (États-Unis). Les auteures retracent ici le parcours singulier de ces objets qui, malgré leur caractère exceptionnel, restent à ce jour encore très peu étudiés., This article looks at the parallel fates of two Unangax̂ (Aleut) collections from the second half of the nineteenth century made by French Alphonse Pinart and American William Dall. Their explorations of Unga Island burial caves, partly driven by their rivalry, resulted in collections of unique and enigmatic objects divided between the Château-Musée de Boulogne-sur-Mer (France) and the Smithsonian Institution National Museum of Natural History (United States). In this article, the authors retrace the particular course of these objects, which, despite their exceptional character, remain understudied.