Pre-Late Wisconsinan Paleoenvironments in Atlantic Canada

Numerous Quaternary organic deposits of various lithologies beneath one or more till units of Wisconsinan age have been discovered in boreholes and exposures in coastal bluffs, quarries and river banks at widespread localities throughout Atlantic Canada. Ongoing palynological and macro-fossil studies, still in a preliminary stage at many sites, reveal a variety of environments from forests dominated by thermophilous hardwood genera and white pine, to mixed temperate hardwood and conifer forests, to boreal coniferous forests of spruce and balsam fir, and forest tundra and tundra communities characterized by spruce, shrubs and herbs. Lithologie and pollen stratigraphie relationships and radiocarbon, amino acid and Thorium/Uranium dating allow a tentative assignment to the Sangamonian Stage and possibly to Early and Middle Wisconsinan time. Three intervals of organic accumulation are apparent: an early interval, when climate became warmer than the present; a second interval, when climate was similar to the present; and a third interval, with cooler climate. The latter interval is characterized by at least three climatic cycles, each one cooler than the previous cycle. Tentative correlations with the deep-sea oxygen isotope record and continental palynological records are presented.Des dépôts organiques aux lithologies variées, surmontés d'au moins une unité de till wisconsinien, ont été découverts dans des trous de forage, dans des coupes le long des falaises littorales et de talus alluviaux, ainsi que dans des carrières en de nombreux endroits des provinces atlantiques. L'étude des macrofossiles et la palynologie de ces dépôts, encore à l'étape préliminaire dans de nombreux cas, révèlent l'existence de différents environnements : forêts dominées par des essences feuillues thermophiles et par le pin blanc; forêts mixtes à essences décidues tolérantes et de conifères; forêts boréales d'épinettes et de sapins baumiers; communautés de toundra forestière et de toundra caractérisée par les épinettes, les arbustes et les herbes. Les corrélations lithologiques et palynostratigraphiques, ainsi que les datations au radio-carbone, aux acides aminées et à l'uranium/ thorium permettent d'attribuer ces dépôts au Sangamonien et probablement au Wisconsinien inférieur et moyen. On distingue trois périodes d'accumulation des sédiments organiques : la première se caractérisait par un climat plus chaud que maintenant; la deuxième, par un climat comparable à celui d'aujourd'hui, la troisième, par un climat plus frais. La dernière période d'accumulation a connu au moins trois cycles climatiques, chacun plus froid que le précédent. On présente également un essai de corrélation entre la courbe de l'oxygène isotopique océanique et les données palynologiques enregistrées sur le continent.Verschiedene organische Ablagerungen aus dem Quartâr mit unterhalb einer oder mehrerer Till-Einheiten aus dem Wisconsin sind in Bohrlôchem und in Schnitten entlang der Steilkùsten, in Steinbrùchen und an FlufJbôschungen an zahlreichen Plàtzen quer durch die Atlantik-Provinzen entdeckt worden. Gegenwârtige palynologische und makrofossile Studien, die sich vielerorts noch in einem Anfangsstadium befinden, lassen eine Umweltvielfalt erkennen, angefangen bei Wâldern, die von thermophilen Hartholzarten und WeiGtannen beherrscht sind, zu Mischwâldern von Hartholz und Nadelbâumen gemâRigten Klimas, zu nôrdlichen Nadelwàldern von Fichten und Balsamtannen, bis zu Wald-Tundra und Tundra-Einheiten, die durch Fichten, Strâucher und Pflanzen gekennzeichnet sind. Lithologische und pollenstratigraphische Beziehungen sowie Radiokarbondatierungen, Aminosâure und Thorium/Uranium-Datierungen erlauben eine vorlàufige Zuordnung zum Sangamon-lnterglazial und moglicherweise zur Zeit des frùhen und mittleren Wisconsin. Drei Perioden organischer Akkumulation sind erkennbar: eine frùhe, als das Klima warmer als heute war; eine zweite, als das Klima dem gegenwàrtigen âhnlich war; und eine dritte mit kàlterem Klima. Dièse letztere ist durch mindestens drei klimatische Zyklen gekennzeichnet, deren jeder kàlter als der vorhergehende Zyklus war. Vorlàufige Korrelationen mit dem Tiefsee Sauerstoff-lsotop Beleg und kontinentalen palynologischen Belegen werden vorgestellt

Tetragonal CuO: A new end member of the 3d transition metal monoxides

Monoclinic CuO is anomalous both structurally as well as electronically in the 3$d$ transition metal oxide series. All the others have the cubic rock salt structure. Here we report the synthesis and electronic property determination of a tetragonal (elongated rock salt) form of CuO created using an epitaxial thin film deposition approach. In situ photoelectron spectroscopy suggests an enhanced charge transfer gap $\Delta$ with the overall bonding more ionic. As an end member of the 3d transition monoxides, its magnetic properties should be that of a high $T_N$ antiferromagnet

MAMS: High resolution atmospheric moisture/surface properties

Multispectral Atmospheric Mapping Sensor (MAMS) data collected from a number of U2/ER2 aircraft flights were used to investigate atmospheric and surface (land) components of the hydrologic cycle. Algorithms were developed to retrieve surface and atmospheric geophysical parameters which describe the variability of atmospheric moisture, its role in cloud and storm development, and the influence of surface moisture and heat sources on convective activity. Techniques derived with MAMS data are being applied to existing satellite measurements to show their applicability to regional and large process studies and their impact on operational forecasting

Testing the public’s response to receiving severe flood warnings using simulated cell broadcast

European Governments must implement a public alerting system to reach mobile phone users affected by major emergencies and disasters by June 2022. Cell Broadcast is used to issue emergency alerts in several countries but has not yet been introduced in the UK. This paper presents the results of a joint research exercise that explored recipients’ responses to cell broadcast messages that warned of floods of varying certainty, severity, and urgency. We adopted a mixed-methods approach employing semi-structured questions and focus groups to assess the perceptions of 80 workshop participants who received simulated emergency alerts on pre-prepared handsets. Our results suggest that although emergency alerting is welcomed, it is necessary to provide accurate and verifiable information, address accessibility challenges, and state location clearly and understandably. This life-saving technology, if used aptly by not over-alerting, specifying the specific urgency, certainty, severity and location of the flood risk, has the real potential of upgrading flood warnings in the UK

Aerosol major ion record at Mount Washington

This study examined the seasonal cycles and regional-scale meteorological controls on the chemical properties of bulk aerosols collected from 1999 to 2004 at Mount Washington, the highest peak in the northeastern United States. The concentrations of NH4+ and SO42− peaked during summer months. The pattern for aerosol NO3− was more complicated with relatively high median concentrations characterizing spring and summer months, but with major elevated events occurring during fall, winter, and spring. The seasonal relationship between NH4+ and SO42− indicated that during warmer months a mixture of (NH4)2SO4 and NH4HSO4 was present, while it was mainly the latter in winter. More acidity and higher concentrations of the major species were generally associated with winds from the southwest and west sectors. The highest (≥95th percentile) concentrations of SO42− and NH4+ were associated with air mass transport from major upwind source regions in the Midwest and along the eastern seaboard. The ionic composition and seasonal cycle observed at Mount Washington were similar to those measured at other northeastern sites, but the range and average concentrations were much lower. These differences were exaggerated during wintertime. Included in this paper are several Eulerian case studies of SO2 conversion to SO42− during transit from Whiteface Mountain, New York, to Mount Washington. The calculations suggest a gas-phase SO2 oxidation rate of ∼1–2% per hour and demonstrate the possibility of using these two sites to investigate the chemical evolution of air masses as they move from Midwestern source regions to northern New England

The Effect of Organic Matter on Maximum Compactability of Soil

Bulk density is the weight of a given volume of soil expressed by soil scientists as grams per cubic centimeter (g/cm3). The higher the bulk density, the lower the volume of soil occupied by pore space, that volume of soil in which air and water reside. Because of this, there is much interest on the degree to which soil can be compacted. The Proctor test is a means of determining the maximum bulk density that can be attained in a soil sample. This maximum compactibility is widely used on highways and building foundations but has had little use in agricultural soils. In the fall of 1994 we began to determine maximum compactability on samples from plots and fields with variable land use history in Kentucky. This is a report of the preliminary results

TREX1 is expressed by microglia in normal human brain and increases in regions affected by ischemia

BACKGROUND: Mutations in the three-prime repair exonuclease 1 (TREX1) gene have been associated with neurological diseases, including Retinal Vasculopathy with Cerebral Leukoencephalopathy (RVCL). However, the endogenous expression of TREX1 in human brain has not been studied. METHODS: We produced a rabbit polyclonal antibody (pAb) to TREX1 to characterize TREX1 by Western blotting (WB) of cell lysates from normal controls and subjects carrying an RVCL frame-shift mutation. Dual staining was performed to determine cell types expressing TREX1 in human brain tissue. TREX1 distribution in human brain was further evaluated by immunohistochemical analyses of formalin-fixed, paraffin-embedded samples from normal controls and patients with RVCL and ischemic stroke. RESULTS: After validating the specificity of our anti-TREX1 rabbit pAb, WB analysis was utilized to detect the endogenous wild-type and frame-shift mutant of TREX1 in cell lysates. Dual staining in human brain tissues from patients with RVCL and normal controls localized TREX1 to a subset of microglia and macrophages. Quantification of immunohistochemical staining of the cerebral cortex revealed that TREX1 CONCLUSIONS: TREX1 is expressed by a subset of microglia in normal human brain, often in close proximity to the microvasculature, and increases in the setting of ischemic lesions. These findings suggest a role for TREX

Analyzing mechanisms and microscopic reversibility of self-assembly

We use computer simulations to investigate self-assembly in a system of model chaperonin proteins, and in an Ising lattice gas. We discuss the mechanisms responsible for rapid and efficient assembly in these systems, and we use measurements of dynamical activity and assembly progress to compare their propensities for kinetic trapping. We use the analytic solution of a simple minimal model to illustrate the key features associated with such trapping, paying particular attention to the number of ways that particles can misbind. We discuss the relevance of our results for the design and control of self-assembly in general.Comment: 11 pages, 8 figures. Discussion clarified in response to referee coment