Stable isotopic analysis of human and faunal remains from the Incipient Chulmun (Neolithic) shell midden site of Ando Island,Korea

We analyzed stable carbon and nitrogen isotope ratios of human and animal remains from the Ando shell midden, South Korea. The Ando site is a rare Incipient Chulmun (Neolithic) site (ca. 6000–5000 BC), which contains well-preserved human and animal bones in shell mounds. The stable isotope results for humans (average δ¹³C = −13.5 ± 0.5‰ and δ¹⁵N = 15.2 ± 0.5‰) indicate that Ando people in the Incipient Chulmun period strongly depended on marine resources. There were no isotopic differences between humans of different sex and age at this site. We compared our data with other previous published isotopic data from the Chulmun sites and found that the Ando people had similar isotope values to the southern Chulmun people (Tongsamdong and Daepo), but different isotopic ratios than the western Chulmun people (Daejukri and Konamri). These results indicate that marine foods were the main food resources in the southern coastal regions, but not in the western coastal regions in Chulmun Korea.     

Neolithic nomadism in south‐east Arabia — strontium and oxygen isotope ratios in human tooth enamel from al‐Buhais 18 and Umm al‐Quwain 2 in the Emirates of Sharjah and Umm al‐Quwain (UAE)

Human skeletal remains from the Neolithic sites BHS18 in the interior of the Sharjah Emirate and the Neolithic shell midden UAQ2 (Umm al‐Quwain) on the coast of the Persian Gulf (United Arab Emirates, UAE) were analysed for their isotope ratios of strontium (⁸⁷Sr/⁸⁶Sr) and oxygen (¹⁸O/¹⁶O). The results are not in agreement with earlier assumptions about a Neolithic nomadism between inland regions and the south‐eastern coast of the Persian Gulf. Existing evidence of nomadic movements of the people from BHS18 most possibly refers to transhumance within the mountains in the hinterland. The strontium isotope measurements on human skeletons from UAQ2 on the contrary indicate uninterrupted residence of this population on the coast. Nevertheless, evidence was found of individual mobility between inland regions and the coast.     

Stable carbon and nitrogen isotope analysis on human remains from the Early Mesolithic site of La Vergne (Charente-Maritime,France)

We report here the results of stable carbon and nitrogen isotope analysis of human and faunal remains from La Vergne (Charente-Maritime, western France), a rare Early Mesolithic burial site (ca. 8500–8000 cal BC). The results for nine humans (average δ¹³C = −19.3‰; δ¹⁵N = 9.4‰) indicate a strongly terrestrial diet, dominated by animal protein, with the possibility of, at best, a slight contribution of marine-derived protein. Given lower sea-levels in the early Holocene, the site would have been some 60–80 km from the sea at the time of its use; nevertheless, contacts with the coast are shown by the presence of numerous marine shell beads in the graves. In the light of the stable isotope results, it is suggested here that such contacts most likely took the form of exchange with coastal communities whose remains now lie underwater.     

The Middle Byzantine menu: palaeodietary information from isotopic analysis of humans and fauna from Kastella,Crete

We report here on the measurements of carbon and nitrogen stable isotopes of bone collagen from the Middle Byzantine site of Kastella, in the city of Heraklion, on the island of Crete, Greece. The data derived from the analysis suggest a diet based primarily on terrestrial, C₃ protein, probably from animal sources, with the inclusion of some marine protein. The adult diet at this site is relatively uniform, with no detectable differences between average isotopic values for males and females. We also found that bone collagen δ¹⁵N values for a small number of juveniles decreased to adult levels after the age of two years, indicating that weaning occurred at or before this age. Copyright © 2006 John Wiley & Sons, Ltd.     

Seasonality and season of birth in early Eneolithic sheep from Cheia (Romania): methodological advances and implications for animal economy

Cheia (early 5th millennium cal BC) is a prehistoric village in the Dobrodgea province in Romania. Its occupation is attributed to the Early Eneolithic period or Hamangia III phase. The exploitation of animal resources is heavily dominated by husbandry. Although cattle are dominant, they were complemented by caprines, mainly sheep, exploited for tender meat (as highlighted by a 6–12 months age class peak in the mortality profile). Sheep reproduction patterns were investigated through stable isotope analyses in order to characterize the annual rhythms of slaughtering for tender meat acquisition while informing a more general picture on sheep demographical management and animal husbandry at the settlement. Results from δ¹⁸O analysis on second and third molar enamel were modeled and compared with modern reference populations. Sheep births took place over less than four months, from late winter to early summer. From this it could be concluded that tender meat could be provided most of the year, excepted over short period in early summer. Finally, comparison of datasets obtained on the M2 and M3 suggests that the M2 presents a more accurate representation of birth seasonality due to lower inter-individual variability in the chronology of tooth growth.     

Assessing the life history of an andean traveller through biogeochemistry: Stable and radiogenic isotope analyses of archaeological human remains from Northern Chile

Bioarchaeology and biogeochemistry can elucidate aspects of individual life histories that are often lost in the archaeological record. Here, we use stable and radiogenic isotope analyses of enamel, bone and hair to reconstruct paleodiet and paleomobility in an adult male interred along a pre‐Columbian route connecting the northern Chilean coast to the inland Loa River Valley. Although this well‐preserved burial included mortuary goods typical of coastal cultures, it was discovered in a vast, uninhabited part of northern Chile's hyper‐arid Atacama Desert. Variation in carbon and nitrogen isotopes reflects dietary differences, while strontium and oxygen isotopes vary geologically and geographically. We use these data to examine paleodiet and paleomobility and to assess whether this was a coastal traveller seeking provisions from the interior or vice versa. Enamel stable isotope analysis is consistent with the consumption of a mixture of terrestrial and marine resources during the first years of life. Bone stable isotope analyses indicate habitual consumption of marine foodstuffs over the last 10–30 years of this individual's life. Interestingly, stable isotope analysis of hair samples provides more fine‐grained information on this individual, suggesting movements between the coast and highlands in the months before his death. Radiogenic strontium isotope data are consistent with residence on the coast or in the Atacama Desert, but are lower than strontium isotope values from higher altitudes. These dietary and geological patterns are reconcilable with coastal residency; the isotopic data are consistent with foodstuffs and textiles found with the burial. Therefore, we argue that this individual was regularly moving from the coast to inland areas, crossing the hyper‐arid Atacama Desert by following strategic interzonal routes that provided access to particular resources. Copyright © 2010 John Wiley & Sons, Ltd.     

Mobility and diet in the Iron Age Pontic forest‐steppe: A multi‐isotopic study of urban populations at Bel'sk

High mobility among Scythian populations is often cited as the driving force behind pan‐regional interactions and the spread of new material culture c.700–200 bce , when burgeoning socioeconomic interactions between the Greeks, Scythian steppe pastoralists and the agro‐pastoral tribes of the forest‐steppe played out across the region. While interregional mobility central to warrior lifestyles is assumed to have been a defining feature of Scythian populations, strikingly few studies have investigated human mobility among communities located along the steppe and forest‐steppe boundary zone. Here, we document movement and dietary intake of individuals interred at Bel'sk, a large urban settlement in Ukraine, through strontium, oxygen and carbon isotope analyses of human tooth enamel. The results provide direct evidence for limited mobility among populations from Bel'sk, demonstrating the movement into, and out of, urban complexes. Strontium and oxygen isotope analyses reveal that groups at Bel'sk remained local to the urban complex. Dietary intake, reflected in carbon isotopes, was based on domesticated crops and livestock herding. The combination of low mobility alongside dietary evidence suggests local groups engaged in sedentary agro‐pastoral subsistence strategies that contrast sharply with the picture of highly mobile Scythian herders dependent on livestock portrayed in historical sources.     

Origin of palaeo‐waters in the Ordovician carbonates in Tahe oilfield,Tarim Basin: constraints from fluid inclusions and Sr,C and O isotopes

Petrographic features, isotopes, and trace elements were determined, and fluid inclusions were analyzed on fracture‐filling, karst‐filling and interparticle calcite cement from the Ordovician carbonates in Tahe oilfield, Tarim basin, NW China. The aim was to assess the origin and evolution of palaeo‐waters in the carbonates. The initial water was seawater diluted by meteoric water, as indicated by bright cathodoluminescence (CL) in low‐temperature calcite. The palaeoseawater was further buried to temperatures from 57 to 110°C, nonluminescent calcite precipitated during the Silurian to middle Devonian. Infiltration of meteoric water of late Devonian age into the carbonate rocks was recorded in the first generation of fracture‐ and karst‐filling dull red CL calcite with temperatures from <50°C to 83°C, low salinities (<9.0 wt%), high Mn contents and high ⁸⁶Sr/⁸⁷Sr ratios from 0.7090 to 0.7099. During the early Permian, ⁸⁷Sr‐rich hydrothermal water may have entered the carbonate rocks, from which precipitated a second generation of fracture‐filling and interparticle calcite and barite cements with salinities greater than 22.4 wt%, and temperatures from 120°C to 180°C. The hydrothermal water may have collected isotopically light CO₂ (possibly of TSR‐origin) during upward migration, resulting in hydrothermal calcite and the present‐day oilfield water having δ¹³C values from ?4.3 to ?13.8‰ and showing negative relationships of ⁸⁷Sr/⁸⁶Sr ratios to δ¹³C and δ¹⁸O values. However, higher temperatures (up to 187°C) and much lower salinities (down to 0.5 wt%) measured from some karst‐filling, giant, nonluminescent calcite crystals may suggest that hydrothermal water was deeply recycled, reduced (Fe‐bearing) meteoric water heated in deeper strata, or water generated from TSR during hydrothermal water activity. Mixing of hydrothermal and local basinal water (or diagenetically altered connate water) with meteoric waters of late Permian age and/or later may have resulted in large variations in salinity of the present oilfield waters with the lowest salinity formation waters in the palaeohighs.     

Residential mobility and social identity in the periphery: strontium isotope analysis of archaeological tooth enamel from southeastern Arabia

Strontium isotope analysis represents an effective means of assessing mobility and reconstructing geographic residence patterns in archaeological populations. This biogeochemical technique was utilized to test the hypothesis that burgeoning interregional exchange networks and the occurrence of exotic grave goods in local tombs would correspond with a highly mobile population and a considerable immigrant presence during the Umm an-Nar (2700–2000 BC) period in the UAE. This region has been considered peripheral relative to larger civilizations in Mesopotamia and the Indus Valley, but played an important role as a major supplier of copper for the Persian Gulf. Individuals (n = 100) from six monumental Umm an-Nar tombs (Mowaihat; Tell Abraq; Umm an-Nar Island I, II, V; Unar 1) were selected to evaluate the geographic origins of tomb members. Mean ⁸⁷Sr/⁸⁶Sr ratios from local individuals interred at Mowaihat (0.708863 ± 0.000014; 1σ, n = 12), Tell Abraq (0.708873 ± 0.000020; 1σ, n = 27), Umm an-Nar Island (0.708902 ± 0.000079; 1σ, n = 33), and Unar 1 (0.708805 ± 0.000065; 1σ, n = 25) all display little isotopic variability, indicative of a population that was not highly mobile. However, coupled with archaeological evidence, three immigrants from Tell Abraq (n = 2) and Mowaihat (n = 1) identified by deviant strontium values suggest that this region was actively engaged in interregional interaction. Despite claims that these tombs acted as visible markers of territoriality legitimized by local ancestors buried within them, the presence of non-locals suggests that as commerce became increasingly important, definitions of kinship and social identity may have become more flexible to better meet the needs of the local community and those with whom they interacted.     

A Palaeodietary Study of Stable Isotope Analysis from a High‐status Burial in the Copper Age: The Montelirio Megalithic Structure at Valencina de la Concepción–Castilleja de Guzmán,Spain

This palaeodietary study presents carbon and nitrogen stable isotope data from human and faunal skeletal remains from the Copper Age settlement of Valencina de la Concepción–Castilleja de Guzmán, located in Seville, Spain. Montelirio, the only Valencina–Castilleja human group from which we have obtained reliable palaeodietary results, had a diet based on C₃ terrestrial resources, including both plants and animals. The protein component of the diet consisted mainly of meat, milk and dairy products from livestock as well as C₃ plant protein from cereals and pulses. This study compares data from Montelirio, the Copper Age group from Valencina–Castilleja, with the published data from other Iberian Late Neolithic–Copper Age (LN‐CA) societies. This comparison reveals a homogeneous diet with some exceptions. Overall, the LN‐CA diet in the Iberian Peninsula consisted mainly of animal proteins from meat, milk and dairy products from livestock as well as C₃ plant sources from the characteristic agriculture of the societies of these periods. This study also demonstrates the minor use of aquatic resources from the Neolithic to the Copper Age period in the Iberian Peninsula. Copyright © 2015 John Wiley & Sons, Ltd.     

Boron isotope geochemistry of Na‐bicarbonate,Na‐chloride,and Ca‐chloride waters from the Northern Apennine Foredeep basin: other pieces of the sedimentary basin puzzle

The boron stable isotope ratio δ¹¹B of 12 water samples representative of three chemical facies (fresh Na‐bicarbonate, brackish Na‐chloride, saline, and brine Ca‐chloride) has been analyzed. Interpretation of the δ¹¹B data, along with the chemical compositions, reveals that Na‐carbonate waters from the Northern Apennine are of meteoric origin, with boron contributions from clay desorption and mixing with seawater‐derived fluids of Na‐chloride or Ca‐chloride compositions. The comparison of our new results with the literature data on other sedimentary basins of Mediterranean, and worldwide, confirms the contribution of Na‐bicarbonate waters to the genesis of mud volcano fluids. The Na‐chloride sample of Salvarola (SAL), which may represent the end‐member of the mud volcanoes, and the Ca‐chloride brine water from Salsomaggiore (SM) indicate boron release from clays compatible with the diagenetic process. The empirical equation: relating boron concentration and the stable isotope composition of the fluids observed in this study and the literature is proposed to trace the effect of diagenesis in sedimentary basins. A geothermometer associated to the diagenetic equation is also proposed: The application of this equation to obtain reservoir temperatures from δ¹¹B compositions of waters should be carefully evaluated against the results obtained from other chemical and isotopic geothermometers from other basins around the world.     

Soil and organic carbon losses from varying land uses: a global meta‐analysis

Soil (SL) and organic carbon losses (SOC_L) have increased with human population and climate change linked extreme events. While SL and SOC_L are clearly associated with surface run‐off, the impact of land use is still not well understood. This article elucidates the effects of land use, surface cover, and other environmental factors on SL and SOC_L using data from 55 published studies. The overall SL (12.34 ± 2.25 Mg ha^?1 year^?1) and SOC_L (21.80 ± 0.91 g C m^?2 year^?1) suggests substantial losses of the fertile topsoil globally. Grasslands (4.19 ± 1.22 Mg ha^?1 year^?1) had 77%, 66%, and 41% lower SL than orchards, croplands, and forests, respectively, which is attributable to higher soil organic matter and surface cover. Croplands had the highest SOC_L at 22.78 ± 2.22 g C m^?2 year^?1. Natural vegetation had 98% and 70% lower run‐off and SL than did plant residue mulched plots, indicating its great potential for surface run‐off and soil erosion control. Rainfall and slope were key drivers of soil erosion, while soil surface cover, SOC, and clay content decreased. These findings improve our knowledge on soil and organic carbon losses, which is useful for fostering sustainable management of soils and natural vegetation to enhance ecosystems functionality.     

High-resolution sclerochronological analysis of the bivalve mollusk Saxidomus gigantea from Alaska and British Columbia: techniques for revealing environmental archives and archaeological seasonality

The butter clam, Saxidomus gigantea, is one of the most commonly recovered bivalves from archaeological shell middens on the Pacific Coast of North America. This study presents the results of the sclerochronology of modern specimens of S. gigantea, collected monthly from Pender Island (British Columbia), and additional modern specimens from the Dundas Islands (BC) and Mink and Little Takli Islands (Alaska). The methods presented can be used as a template to interpret local environmental conditions and increase the precision of seasonality estimates in shellfish using sclerochronology and oxygen isotope analysis. This method can also identify, with a high degree of accuracy, the date of shell collection to the nearest fortnightly cycle, the time of day the shell was collected and the approximate tidal elevation (i.e., approx. water depth and distance from the shoreline) from which the shell was collected.Life-history traits of S. gigantea were analyzed to understand the timing of growth line formation, the duration of the growing season, the growth rate, and the reliability of annual increments. We also examine the influence of the tidal regime and freshwater mixing in estuarine locations and how these variables can affect both incremental structures and oxygen isotope values. The results of the sclerochronological analysis show that there is a latitudinal trend in shell growth that needs to be considered when using shells for seasonality studies.Oxygen isotope analysis reveals clear annual cycles with the most positive values corresponding to the annual winter growth lines, and the most negative values corresponding to high temperatures during the summer. Intra-annual increment widths demonstrate clear seasonal oscillations with broadest increments in summer and very narrow increments or no growth during the winter months. This study provides new insights into the biology, geochemistry and seasonal growth of S. gigantea, which are crucial for paleoclimate reconstructions and interpreting seasonality patterns of past human collection.     

New Dietary Evidence on Medieval Rural Communities of the Basque Country (Spain) and Its Surroundings from Carbon and Nitrogen Stable Isotope Analyses: Social Insights,Diachronic Changes and Geographic Comparison

This paper presents the results of palaeodietary reconstruction based on stable carbon and nitrogen isotope analysis on bone collagen of five medieval rural populations from the Basque Country (northern Spain) spanning from 5^th to 15^th centuries ad . One hundred forty‐seven human and 47 domestic faunal samples were successfully analysed with the objective of defining agrarian productive strategies and food consumption patterns. The results grouped the five sites in two clusters: on one side Zaballa and Treviño, whose inhabitants followed diets exclusively based on C₃ plants with significant intake of animal protein, and on the other, the populations from Aistra and Zornoztegi, who combined C₃ and C₄ plants and consumed lower amounts of animal protein. The isotopic values from Dulantzi were intermediate to these two groups. No differences were detected when individual status markers, such as grave goods, were available. Conversely, some restrictions on the access to certain food resources based on sex were uncovered. A relevant change in δ¹³C values was identified around 10^th century, a consequence of a shift in the consumption patterns of C₃ and C₄ plants. Finally, these Basque sites were compared with those of the medieval Iberian case studies available in the literature. This comparison made evident the distinctive nature of the diet of the Basque medieval rural contexts. Copyright © 2017 John Wiley & Sons, Ltd.     

Reconstructing Life Histories Using Multi‐Tissue Isotope Analysis of Commingled Remains from St Stephen's Monastery in Jerusalem: Limitations and Potential

The examination of isotope ratios from multiple tissues offers new life to interpretations of commingled assemblages where information regarding individual biological history has been lost. Here, life histories from a commingled sample of Byzantine monks were reconstructed using enamel and bone δ¹³C and δ¹⁵N values. The δ¹³C values suggest a diet dominated by C₃ products, while the δ¹⁵N ratios indicate variable contributions of animal protein. After correcting for tissue‐specific enrichment factors, bone δ¹³C values were significantly enriched over enamel; this may be due to an increase in protein consumption, but could also reflect structural differences between tissues or correction factors used to compare these data.     

Mummies, maize, and manure: multi-tissue stable isotope analysis of late prehistoric human remains from the Ayacucho Valley, Perú

This paper reports the δ¹³C and δ¹⁵N values of bone collagen, muscle and skin from several late prehistoric–early colonial (AD 1490–1640) mummies from Perú's Ayacucho Valley. The mean of the δ¹³C and δ¹⁵N values of bone collagen are −11.5 ± 1.4 and 11.1 ± 0.7‰, respectively. The mean of the δ¹³C values for Vinchos skin is −11.8 ± 1.2‰ and the mean of δ¹⁵N values is 13.2 ± 0.5‰. The samples of muscle tissue have a δ¹³C mean of −11.9 ± 0.9‰ and a δ¹⁵N mean of 12.7 ± 0.3‰. The data from bone collagen indicate maize was the basis of the region's subsistence economy. A significant correlation between δ¹³C and δ¹⁵N values of bone collagen (R² = 0.75) is consistent with the preferential fertilization of maize with composted manure. Both skin and muscle samples are consistently enriched in δ¹⁵N relative to paired samples of bone (2.1 ± 0.5 and 1.6 ± 0.7‰, respectively), possibly as a result of short term physiological stress or differential decomposition.     

Shell-gathering from mangroves and the seasonality of the Southeast Asian Monsoon using high-resolution stable isotopic analysis of the tropical estuarine bivalve (Geloina erosa) from the Great Cave of Niah, Sarawak: methods and reconnaissance of molluscs of early Holocene and modern times

This paper describes a reconnaissance, high-resolution, study of stable isotopes (δ¹⁸O and δ¹³C) from modern shells of the estuarine bivalve Geloina erosa, and those dated to the early Holocene that were harvested by people from mangroves near the Great Cave of Niah on the north coast of Borneo. This reconnaissance study provides high-resolution palaeoclimatic-palaeohydrological information concerning early human activity in the region and the past character of the Southeast Asian Monsoon. Laser ablation continuous flow isotope ratio mass spectrometry (LA-CF-IRMS) on modern shells of Geloina erosa revealed ‘saw-tooth’ stable isotopic profiles that bear a close resemblance to peaks and troughs of trends in recent local rainfall, including the 1998 El Niño drought, highlighting the potential of Geloina erosa for reconstructing seasonality of the Southeast Asian Palaeomonsoon. LA-CF-IRMS analysis of prehistoric shells of Geloina erosa held in the Harrisson Archives of the Sarawak Museum revealed cyclical shifts in δ¹⁸O with similar amplitudes of variation as found in modern shells of Geloina erosa. As at the present day, this probably reflects the changing seasonality of the monsoon rains with shifts to negative δ¹⁸O values during periods of high runoff. Lighter mean δ¹⁸O values of the prehistoric shells, however, may indicate a greater annual surplus of rainfall and possibly consistent with the early Holocene strengthening of the summer monsoon at that time. The similarity of the last growth increment δ¹⁸O of the prehistoric shells to their mean δ¹⁸O profile values suggests that gathering took place during times of moderate runoff.     

Hunter–gatherer foraging ranges, migrations, and travel in the middle Holocene Baikal region of Siberia: Insights from carbon and nitrogen stable isotope signatures

Foraging ranges, migrations, and travel among Middle Holocene hunter–gatherers in the Baikal region of Siberia are examined based on carbon and nitrogen stable isotope signatures obtained from 350 human and 203 faunal bone samples. The human materials represent Early Neolithic (8000–6800 cal BP), Late Neolithic (6000–5000 cal BP), and Early Bronze Age periods (∼5000–4000 cal BP) and come from the following four smaller areas of the broader region: the Angara and upper Lena valleys, Little Sea of Baikal’s northwest coast, and southwest Baikal. Forager diets from each area occupy their own distinct position within the stable isotope spectrum. This suggests that foraging ranges were not as large as expected given the distances involved and the lack of geographic obstacles between the micro-regions. All examined individuals followed a similar subsistence strategy: harvesting game and local fishes, and on Lake Baikal also the seal, and to a more limited extent, plant foods. Although well established in their home areas, exchange networks with the other micro-regions appear asymmetrical both in time and direction: more travel and contacts between some micro-regions and less between others. The Angara valley seems to be the only area with the possibility of a temporal change in the foraging strategy from more fishing during the Early Neolithic to more ungulate hunting during the Late Neolithic–Early Bronze Age. However, the shift in stable isotope values suggesting this change can be viewed also as evidence of climate change affecting primary productivity of the Baikal–Angara freshwater system.     

Assessing Recovery from the 2004 Indian Ocean Tsunami: An Application of Night‐time Light Data and Vegetation Index

It has been 10 years since the Indian Ocean Tsunami caused serious damage to the coastal areas in South and Southeast Asia. The effects on vegetation and human settlements in the affected areas were enormous. This study presents the results of an analysis estimating the long‐term recovery using two longitudinal remotely sensed dataset: 1. Moderate Resolution Imaging Spectroradiometer enhanced vegetation index (MODIS EVI), a dataset accounting for change in the landscape and vegetation; and 2. Defense Meteorological Satellite Program‐Optical Line Scanner (DMSP‐OLS) night‐time light data in order to estimate the effects on human and economic activities. It is evident from the results of this study that the night‐time light and vegetation index datasets can both be beneficial in identifying changes caused by natural disasters and can be used to track recovery. The results using night‐time light indicates a large loss of lighted area but also a rapid recovery of night‐time light after the tsunami. Already in year 2005–2006, the levels of lighted area and sum of the lighting (SOL) intensity reached the same levels as pre‐tsunami. For MODIS vegetation index, a drop can be observed in 2005/2006 on locations close to the coastline using 1 year temporal resolution; however, when utilizing the 16 day temporal resolution, the impact of the tsunami is illustrated as a dramatic drop, mostly in pixels located within 3km from the coast. Following the drop in vegetation index due to the tsunami, it was observed that most pixels exhibited at least some level of recovery in 2 years after the event.