Carotid Atheroinflammation Is Associated With Cerebral Small Vessel Disease Severity.

Background: Atherosclerosis is a systemic inflammatory disease, with common inflammatory processes implicated in both atheroma vulnerability and blood-brain barrier disruption. This prospective multimodal imaging study aimed to measure directly the association between systemic atheroma inflammation ("atheroinflammation") and downstream chronic cerebral small vessel disease severity. Methods: Twenty-six individuals with ischemic stroke with ipsilateral carotid artery stenosis of >50% underwent 18fluoride-fluorodeoxyglucose-positron emission tomography within 2 weeks of stroke. Small vessel disease severity and white matter hyperintensity volume were assessed using 3-tesla magnetic resonance imaging also within 2 weeks of stroke. Results: Fluorodeoxyglucose uptake was independently associated with more severe small vessel disease (odds ratio 6.18, 95% confidence interval 2.1-18.2, P < 0.01 for the non-culprit carotid artery) and larger white matter hyperintensity volumes (coefficient = 14.33 mL, P < 0.01 for the non-culprit carotid artery). Conclusion: These proof-of-concept results have important implications for our understanding of the neurovascular interface and potential therapeutic exploitation in the management of systemic atherosclerosis, particularly non-stenotic disease previously considered asymptomatic, in order to reduce the burden of chronic cerebrovascular disease

#35 - Enamel isotopes reveal late Pleistocene ecosystem dynamics in southeastern North America

The end of the late Pleistocene (~10,000 years ago) witnessed the extinction of over seventy percent of North America’s megafaunal genera. Although this pattern has been extensively investigated, its causal mechanisms remain elusive. Much of this difficulty is related to the spatial and temporal discontinuity of sites dating to the period leading up to the extinctions. Due to its removal from glacial conditions, southeastern North America provides a unique window into ecosystem dynamics just prior to human arrival in the region. In this study, we present new stable carbon and oxygen isotope data from Mammuthus columbiand Bison latifronsteeth collected from a well-dated Last Glacial Maximum (~20,000 rcybp) locality called Clark Quarry in coastal Georgia, USA. We compare these data to those from similarly aged (middle and late Rancholabrean) localities from Florida and demonstrate the presence of a vegetation gradient with elevated levels of C3vegetation at higher latitudes. We hypothesize that this pattern may have contributed to previously described migratory patterns of mastodon (Mammut) populations in southeastern North America. Serially-sampled δ13C and δ18O values suggest that Clark Quarry Mammuthus and Bison changed their diet seasonally with the incorporation of elevated quantities of C4vegetation during warmer periods. Our data indicate more exaggerated seasonal dietary variability in these taxa at Clark Quarry relative to those collected from the interglacial locality of Waccasassa River in Florida, providing additional evidence for the significant influence of glacial dynamics in structuring North American ecosystems

Reviews

Lord of the Rings - Part 1 (film). Ralph Bakshi. Reviewed by Jessica Yates. A Reader\u27s Guide to The Silmarillion. Paul H. Kocher. Reviewed by Nancy-Lou Patterson. Dancing in the Dragon\u27s Jaws (album). Bruce Cockburn. Reviewed by Gord Wilson. Metropolis. Thea von Harbou. Reviewed by Thomas M. Egan. One Ring to Bind Them All: Tolkien\u27s Mythology. Anne C. Petty. Reviewed by Thomas Santoski. The Literature of Fantasy: A Comprehensive, Annotated Bibliography of Modern Fantasy Fiction. Roger C. Schlobin. Reviewed by Joe R. Christopher. The Screwtape Letters. C.S. Lewis. Illustrated by Papas. Reviewed by Kathryn Lindskoog

“We Used to Say Rats Fell from the Sky After a Flood:” Temporary Recovery of Muskrat Following Ice Jams in the Peace-Athabasca Delta

Elders and Indigenous land users in the Peace-Athabasca Delta (PAD) have observed a dramatic decline in the relative abundance of muskrat in recent decades (~1935–2014). The main explanation for the decline has been reduction in suitable habitat as a result of decades with reduced frequency of ice-jam flooding on the Peace River. Under favourable conditions, ice jams can cause flooding of perched basins within the PAD that would otherwise receive no recharge from floodwaters. To examine whether abundance of muskrat in the PAD is driven by flooding, we tested the predictions that the density of muskrat (estimated by winter counts of houses) (1) was inversely related to the number of years since major ice jam floods and (2) increased with water depth. An ongoing collaborative monitoring program initiated in 2011, combined with analysis of data from past surveys (1973–2015), allowed Indigenous land users and scientists to document a 10 to 100-fold increase in the density of muskrat houses in 24 basins, over the two years following ice-jam flood events in the PAD. During 1973–2015, in the periods between major floods, density of houses dropped by approximately 79% for every year after a significant flood. In 27 basins surveyed from 2011 to 2015, density of muskrat houses increased by two orders of magnitude in the two years following a flood in the spring of 2014. Density of muskrat houses had a non-linear relationship with estimated depth of water at the time of fall freeze-up; the highest densities of muskrat houses were in basins with about 60 – 250 cm of water at the time of freeze-up. The depth of snow at the time of surveys did not have a strong relationship with the density of muskrat houses. However, few houses were counted in basins with more than 20 cm of snow, likely because deeper snow made it more difficult to conduct surveys and spot houses. Factors other than an increase in the depth of water at fall freeze-up may provide the mechanisms by which flooding affects muskrat. Density of muskrat houses is clearly tied to ice-jam flooding in the PAD. However, the local mechanisms by which floods affect muskrat are best understood by Indigenous land users and remain poorly understood by Western science. Indigenous peoples continue to regard muskrat as an indicator of ecological and cultural health of the PAD. This study highlights the value of consistent ecological monitoring that includes Indigenous knowledge.Les aînés et les utilisateurs des terres autochtones du delta des rivières de la Paix et Athabasca ont observé une baisse draconienne de l’abondance du rat musqué au cours des dernières décennies (~1935-2014). La principale explication du déclin est la diminution d’abris convenables, et ce, en raison de plusieurs décennies marquées par la fréquence réduite d’inondations causées par des embâcles dans la rivière de la Paix. Dans des conditions favorables, les embâcles peuvent causer l’inondation des bassins perchés au sein du delta des rivières de la Paix et Athabasca qui autrement ne recevraient pas de recharge des eaux de crue. Afin d’examiner si l’abondance du rat musqué dans le delta des rivières de la Paix et Athabasca est favorisée par les inondations, nous avons testé des prévisions selon lesquelles la densité du rat musqué (estimée par le nombre d’abris en hiver) 1) était inversement liée au nombre d’années depuis les dernières importantes inondations causées par des embâcles et 2) augmentait avec la profondeur de l’eau. Un programme collaboratif de suivi continu lancé en 2011, combiné à l’analyse de données des relevés antérieurs (1973-2015), a permis aux utilisateurs des terres autochtones et aux scientifiques de multiplier de 10 à 100 fois la densité d’abris du rat musqué dans 24 bassins, au cours des deux années suivant des événementsd’inondation causés par des embâcles dans le delta des rivières de la Paix et Athabasca. Entre 1973 et 2015, durant les périodes se situant entre les inondations importantes, la densité d’abris a diminué d’environ 79 % chaque année suivant une inondation importante. Dans 27 bassins sondés entre 2011 et 2015, la densité d’abris du rat musqué a augmenté de deux ordres de grandeur au cours des deux années ayant suivi une inondation survenue au printemps de 2014. La densité d’abris du rat musqué avait une relation non linéaire avec la profondeur de l’eau estimée au moment de la prise des glaces en automne; les plus fortes densités d’abris du rat musqué se trouvaient dans les bassins ayant de 60 à 250 cm d’eau au moment de la prise des glaces. La profondeur de la neige au moment des relevés n’avait pas de relation solide avec la densité d’abris du rat musqué. Cependant, nous avons compté peu d’abris dans les bassins comptant plus de 20 cm de neige, probablement parce qu’il était plus difficile d’effectuer des relevés et de trouver les abris dans la neige plus épaisse. Des facteurs autres que l’augmentation de la profondeur de l’eau au moment de la prise des glaces en automne pourraient fournir les mécanismes par lesquels les inondations se répercutent sur les rats musqués. La densité d’abris du rat musqué est manifestement liée aux inondations causées par des embâcles dans le delta des rivières de la Paix et Athabasca. Toutefois, les utilisateurs des terres autochtones comprennent mieux les mécanismes locaux par lesquels les inondations se répercutent sur les rats musqués, tandis qu’ils demeurent mal compris par la science occidentale. Les peuples autochtones continuent de considérer le rat musqué comme un indicateur de la santé écologique et culturelle du delta des rivières de la Paix et Athabasca. Cette étude fait ressortir la valeur d’un suivi écologique constant qui tient compte des connaissances autochtones

A framework for evaluating the influence of climate, dispersal limitation, and biotic interactions using fossil pollen associations across the late Quaternary

Environmental conditions, dispersal lags, and interactions among species are major factors structuring communities through time and across space. Ecologists have emphasized the importance of biotic interactions in determining local patterns of species association. In contrast, abiotic limits, dispersal limitation, and historical factors have commonly been invoked to explain community structure patterns at larger spatiotemporal scales, such as the appearance of late Pleistocene no-analog communities or latitudinal gradients of species richness in both modern and fossil assemblages. Quantifying the relative influence of these processes on species co-occurrence patterns is not straightforward. We provide a framework for assessing causes of species associations by combining a null-model analysis of co-occurrence with additional analyses of climatic differences and spatial pattern for pairs of pollen taxa that are significantly associated across geographic space. We tested this framework with data on associations among 106 fossil pollen taxa and paleoclimate simulations from eastern North America across the late Quaternary. The number and proportion of significantly associated taxon pairs increased over time, but only 449 of 56 194 taxon pairs were significantly different from random. Within this significant subset of pollen taxa, biotic interactions were rarely the exclusive cause of associations. Instead, climatic or spatial differences among sites were most frequently associated with significant patterns of taxon association. Most taxon pairs that exhibited co-occurrence patterns indicative of biotic interactions at one time did not exhibit significant associations at other times. Evidence for environmental filtering and dispersal limitation was weakest for aggregated pairs between 16 and 11 kyr BP, suggesting enhanced importance of positive species interactions during this interval. The framework can thus be used to identify species associations that may reflect biotic interactions because these associations are not tied to environmental or spatial differences. Furthermore, temporally repeated analyses of spatial associations can reveal whether such associations persist through time

Ancient DNA and deep population structure in sub-Saharan African foragers

Multiple lines of genetic and archaeological evidence suggest that there were major demographic changes in the terminal Late Pleistocene epoch and early Holocene epoch of sub-Saharan Africa(1-4). Inferences about this period are challenging to make because demographic shifts in the past 5,000 years have obscured the structures of more ancient populations(3,5). Here we present genome-wide ancient DNA data for six individuals from eastern and south-central Africa spanning the past approximately 18,000 years (doubling the time depth of sub-Saharan African ancient DNA), increase the data quality for 15 previously published ancient individuals and analyse these alongside data from 13 other published ancient individuals. The ancestry of the individuals in our study area can be modelled as a geographically structured mixture of three highly divergent source populations, probably reflecting Pleistocene interactions around 80-20 thousand years ago, including deeply diverged eastern and southern African lineages, plus a previously unappreciated ubiquitous distribution of ancestry that occurs in highest proportion today in central African rainforest hunter-gatherers. Once established, this structure remained highly stable, with limited long-range gene flow. These results provide a new line of genetic evidence in support of hypotheses that have emerged from archaeological analyses but remain contested, suggesting increasing regionalization at the end of the Pleistocene epoch. DNA analysis of 6 individuals from eastern and south-central Africa spanning the past approximately 18,000 years, and of 28 previously published ancient individuals, provides genetic evidence supporting hypotheses of increasing regionalization at the end of the Pleistocene.info:eu-repo/semantics/publishedVersio

Using statolith elemental signatures to confirm ontogenetic migrations of the squid Doryteuthis gahi around the Falkland Islands (Southwest Atlantic)

This work was supported by the Falkland Islands Government. We thank Dr. Simon Chenery and the British Geological Survey for assistance with the LA-ICP-MS analysis and training and use of their facilities. We are grateful to the scientific observers from the Falkland Islands Fisheries Department for sample collection. We thank the Director of Fisheries, John Barton, and the director of SAERI, Paul Brickle, for supporting this work. We thank Dr. Elena Ieno, Dr. Andreas Winter, Dr. Haseeb Randhawa and three anonymous reviewers for their helpful comments that greatly improved the manuscript.Peer reviewedPostprin

IL4I1 Is a Metabolic Immune Checkpoint that Activates the AHR and Promotes Tumor Progression

Immune checkpoint blockade therapy induces the AHR-activating enzyme IL4I1, which promotes tumor progression, through its effects on tumor cell motility and adaptive immunity

Tracing Changes in Families Who Participated in the Home-Start Parenting Program: Parental Sense of Competence as Mechanism of Change

The present study aimed to (1) determine the long-term effectiveness of Home-Start, a preventive parenting program, and (2) test the hypothesis that changes in maternal sense of competence mediate the program’s effects. Participants were 124 mothers (n = 66 intervention, n = 58 comparison). Four assessments took place during a 1-year period. Latent growth modeling showed that Home-Start enhanced growth in maternal sense of competence and supportive parenting, and led to a decrease in the use of inept discipline. Results of mediational and cross-lagged analyses were consistent with the hypothesized model: Participation in Home-Start was related to the changes in maternal sense of competence, which in turn predicted changes in parenting. The results affirm the importance of directly targeting parental sense of competence in the context of prevention work with parents