Aspects of the Postglacial Climate of Alberta: Calibration of the Pollen Record

This reconstruction of the postglacial climate of Alberta is based on a review of pollen studies within the province and the application of calibration equations to a pollen record from central Alberta. Regional palynological studies indicate that the late glacial vegetation, dominated by non-arboreal taxa and, on occasion, Populus, was replaced by a Picea dominated assemblage between 12,000 and 10,000 BP. In central Alberta, increased herbaceous pollen representation suggests that grassland was established north of its current position in early to middle Holocene time. By 3500 BP, the grassland boundary had retreated southward. Little vegetational change is evident during the last 3500 years. Calibration equations, derived from modern pollen and climatic data in the western interior of Canada and applied to an 11,400 year pollen record, suggest growing season temperature was 1.5°C greater than at present while growing season precipitation was 50 mm below current values during the middle Holocene.La reconstitution du climat postglaciaire de l'Alberta présentée ici est fondée sur les études palynologiques portant sur l'Alberta et sur l'application d'équations d'étalonnage aux données polliniques du centre de l'Alberta. Les études palynologiques régionales démontrent que la végétation tardiglaciaire, dominée par des taxons non arboréens, et à l'occasion par Populus, a été remplacée par des associations dominées par Picea entre 12 000 et 10 000 BP. Au centre de l'Alberta, l'augmentation de la représentation du pollen d'herbacées laissent croire que la prairie était établie au nord de sa position actuelle du début jusqu'au milieu de l'Holocène. Dès 3500 BP, la limite de la prairie était déjà plus méridionale. Peu de changements se sont manifestés depuis 3500 ans. Les équations d'étalonnage, faites à partir des données polliniques et climatiques actuelles provenant de la partie ouest de l'intérieur du Canada et appliquées à un inventaire portant sur 11 400 ans, laissent croire qu'au milieu de l'Holocène la température au cours de la saison végétative était de 1,5oC supérieure à maintenant et que les précipitations durant cette saison étaient inférieures de 50 mm à maintenant.Dièse Rekonstruktion des postglazialen Klimas von Alberta beruht auf einer Ubersicht ùber die Pollen-Studien in der Provinz und der Anwendung der KaIibrierungs-Gleichungen auf die Pollen-Belege von Zentral-Alberta. Régionale palynologische Studien zeigen, dap die spàtglaziale Vegetation, welche durch nichtbaumartige Taxa und gelegentlich durch Populus beherrscht war, zwischen 12,000 und 10,000 v.u.Z. durch eine von Picea beherrschte Ansammlung ersetzt wurde. In Zentral-Alberta làpt zunehmendes pflanzliches Pollen-Vorkommen vermuten, dap Grasland in der Zeit des frùhen bis mittleren Holozân nôrdlich seiner jetzigen Position vorhanden war. Um 3500 v.u.Z. war die Grasland-Grenze sùdwârts zurùckgewichen. Wàhrend der letzten 3500 Jahre sind wenige Wechsel in der Vegetation aufgetreten. Die Kalibrierungs-Gleichungen, die aus modernen Pollen- und Klima-Daten im inneren Westen von Kanada gewonnen wurden und auf einen 11,400 Jahre alten Pollen-Beleg angewendet werden, lassen vermuten, daB im mittleren Holozàn die Temperatur der Wachstumszeit um 1.5°C hôher war als heute, wàhrend der Niederschlag in der Wachstumszeit um 50 mm unter den heutigen Werten lag

The Paleoecological Record of 6 ka BP Climate in the Canadian Prairie Provinces

Synthesis of available paleoecological studies in the Prairie provinces of Canada indicates that although the peak in postglacial aridity that characterized early Holocene climate of the western foothills and plains had passed, conditions remained warmer and drier than present throughout the region ca. 6000 yr BP Compared to today, treeline elevations were higher and alpine glaciers were reduced in size in the Rocky Mountains, lake levels were lower over much of the Interior Plains, and the grassland and boreal forest ecozones extended north of their present positions. Forest fires were more prevalent ca. 6000 yr BP than they are today, aiding westward migration of jack pine (Pinus banksiana) through the boreal forest and increasing the area occupied by grassland in boreal and montane forest regions. Attempts to quantify the magnitude of 6 ka temperature and precipitation differences have produced variable results, but suggest that mean annual temperature was 0.50°C to 1.50°C higher than today (summer temperature may have been up to 3°C higher) and mean annual precipitation was reduced by 65 mm (or summer precipitation was reduced by 50 mm), compared to present. The nature and scale of these changes suggests that a vigorous zonal atmospheric circulation pattern, similar to that of the 1930s but shifted northward, prevailed at 6 ka.La synthèse des études paléoécologiques montrent qu'à 6 ka le maximum d'aridité, qui caractérisait l'Holocène inférieur, avait été atteint, mais le climat demeurait plus chaud et plus sec que maintenant dans toute la région. Les différentes limites des arbres étaient plus élevées qu'aujourd'hui et la superficie des glaciers alpins étaient plus petite, les niveaux lacustres étaient moins élevés dans la plus grande partie des plaines intérieures et les écozones des Prairies et de la forêt boréale s'étendaient plus au nord qu'aujourd'hui. Les feux de forêt étaient plus fréquents à 6 ka qu'actuellement, ce qui a favorisé la migration du pin gris (Pinus banksiana) vers l'ouest à travers la forêt boréale et accru la superficie de la prairie dans les zones de forêts boréale et alpine. Les essais faits dans le but de mesurer l'ampleur des différences de températures et de précipitations à 6 ka ont donné des résultats variables, mais montrent que la température était de 0,5 à 1,5°C plus élevé que maintenant (avec une température estivale jusqu'à 3°C plus élevée) et les précipitations annuelles moyennes étaient de 65 mm inférieures (avec des précipitations estivales de 50 mm inférieures) à maintenant. La nature et le degré des changements laissent croire qu'une forte circulation atmosphérique zonale, semblable à celle des années 1930, mais plus nordique, existait à 6 ka.Die Synthèse der verfùgbaren palâoôkologischen Studien in den Prârie-Provinzen Kanadas zeigt, daf3 das Klima in der ganzen Region um etwa 6000 Jahre v.u.Z. warmer und trockener als gegenwârtig blieb, wenn auch das Maximum an postglazialer Trockenheit, welches im frùhen Holozàn das Klima der westlichen Gebirgsauslâufer und Ebenen charakterisierte, vorùber war. Verglichen mit heute waren die Baumgrenzen hôher und die alpinen Gletscher in den Rocky Mountains kleiner, die Seehôhen waren niedriger im grôBten Teil der inneren Ebenen, und die Ôkozonen von Grasland und nôrdlichem WaId erstreckten sich weiter nôrdlich als heute. Waldbrânde traten um etwa 6000 v.u.Z. hâufiger als gegenwârtig auf und haben so die Westwàrtswanderung von Graukiefer (Pinus banksiana) durch den nôrdlichen WaId begùnstigt und die Graslandflàchen in den Gebieten des nôrdlichen und alpinen Waldes vergrôBert. Versuche, den Umfang der Unterschiede in Temperatur und Niederschlàgen um 6 ka zu bestimmen, ergaben wechselnde Ergebnissse, doch zeigen sie, daB die durchschnittliche jâhrliche Temperatur 0.5° C bis 1.50C hôher als gegenwârtig war (die Sommertemperatur dûrfte bis zu 3°C hôher gewesen sein) und die durchschnittlichen jâhrlichen Niederschlâge waren um 65 mm geringer (oder die Sommer-Niederschlàge waren um 50 mm geringer) verglichen mit heute. Die Natur und der Grad dieser Wechsel lassen vermuten, daB eine krâftige zonale atmosphàrische Strômung, àhnlich der von den 1930 iger Jahren aber nôrdlicher gelagert, um 6 ka vorherrschte

Otterbein Miscellany , May 1970

https://digitalcommons.otterbein.edu/miscellany/1018/thumbnail.jp

LACTB is a tumour suppressor that modulates lipid metabolism and cell state

Post-mitotic, differentiated cells exhibit a variety of characteristics that contrast with those of actively growing neoplastic cells, such as the expression of cell-cycle inhibitors and differentiation factors. We hypothesized that the gene expression profiles of these differentiated cells could reveal the identities of genes that may function as tumour suppressors. Here we show, using in vitro and in vivo studies in mice and humans, that the mitochondrial protein LACTB potently inhibits the proliferation of breast cancer cells. Its mechanism of action involves alteration of mitochondrial lipid metabolism and differentiation of breast cancer cells. This is achieved, at least in part, through reduction of the levels of mitochondrial phosphatidylserine decarboxylase, which is involved in the synthesis of mitochondrial phosphatidylethanolamine. These observations uncover a novel mitochondrial tumour suppressor and demonstrate a connection between mitochondrial lipid metabolism and the differentiation program of breast cancer cells, thereby revealing a previously undescribed mechanism of tumour suppression

Novel mutations support a role for Profilin 1 in the pathogenesis of ALS

AbstractMutations in the gene encoding profilin 1 (PFN1) have recently been shown to cause amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disorder. We sequenced the PFN1 gene in a cohort of ALS patients (n = 485) and detected 2 novel variants (A20T and Q139L), as well as 4 cases with the previously identified E117G rare variant (∼ 1.2%). A case-control meta-analysis of all published E117G ALS+/− frontotemporal dementia cases including those identified in this report was significant p = 0.001, odds ratio = 3.26 (95% confidence interval, 1.6–6.7), demonstrating this variant to be a susceptibility allele. Postmortem tissue from available patients displayed classic TAR DNA-binding protein 43 pathology. In both transient transfections and in fibroblasts from a patient with the A20T change, we showed that this novel PFN1 mutation causes protein aggregation and the formation of insoluble high molecular weight species which is a hallmark of ALS pathology. Our findings show that PFN1 is a rare cause of ALS and adds further weight to the underlying genetic heterogeneity of this disease

LACTB is a tumour suppressor that modulates lipid metabolism and cell state

Post-mitotic, differentiated cells exhibit a variety of characteristics that contrast with those of actively growing neoplastic cells, such as the expression of cell-cycle inhibitors and differentiation factors. We hypothesized that the gene expression profiles of these differentiated cells could reveal the identities of genes that may function as tumour suppressors. Here we show, using in vitro and in vivo studies in mice and humans, that the mitochondrial protein LACTB potently inhibits the proliferation of breast cancer cells. Its mechanism of action involves alteration of mitochondrial lipid metabolism and differentiation of breast cancer cells. This is achieved, at least in part, through reduction of the levels of mitochondrial phosphatidylserine decarboxylase, which is involved in the synthesis of mitochondrial phosphatidylethanolamine. These observations uncover a novel mitochondrial tumour suppressor and demonstrate a connection between mitochondrial lipid metabolism and the differentiation program of breast cancer cells, thereby revealing a previously undescribed mechanism of tumour suppression

The La Prele Mammoth Site, Converse County, Wyoming, USA

The La Prele Mammoth site is a Clovis archaeolog- ical site in Converse County, Wyoming (U.S.A.) that preserves chipped stone artifacts in spatial as- sociation with the remains of a subadult Columbi- an mammoth (Mammuthus columbi). The site was discovered in 1986 and initially tested by George Frison in 1987, but work ceased there until 2014 due to a disagreement with the landowner. In the intervening years, questions arose as to whether the artifacts and mammoth remains were truly associated, and the site was largely dismissed by American archaeologists. Recent excavations have not only demonstrated that La Prele was the loca- tion of a mammoth kill by Clovis hunters around 12,850 years ago, but it also preserves a campsite in close proximity to the kill. The camp includes multiple hearth-centered activity areas that appear to represent domestic spaces, reflected by the pres- ence of a diversity of stone tool forms, bone nee- dles, a bone bead, a large area of hematite-stained matrix, and the butchered and cooked remains of at least one other large mammal species. The site has the potential to inform us about aspects of the social organization of Clovis bands, particularly with respect to mammoth hunting and butchery.The symposium and the volume "Human-elephant interactions: from past to present" were funded by the Volkswagen Foundation