Conifer wood, probably spruce (Picea sp.), of middle Wisconsinan age (29,200 ± 500 yr B.P.) was recovered from late-glacial lake sediments from Upper South Branch Pond, Maine. If the wood was derived from a local source, deglaciation of part of northern New England is suggested for this time. The occurrence also has implications for understanding the problem associated with radiocarbon dating of bulk lake sediment containing small amounts of organic matter.

Pollen influx and percentage diagrams were prepared from an 11.4 m core from Moulton Pond, Maine. The pond basin was deglaciated about 14,000 y. a., after which it was located on an island in a sea of subarctic character until about 12,400 y. a. when the surrounding area emerged from the sea. The terrestrial vegetation was tundra until about 10,000 y. a. A change in the tundra vegetation is synchronous with the emergence from the sea, but synchroneity with the Pineo Ridge glacial readvance, which reached its maximum 50 km to the east of the pond about 12,700 y. a., is also possible because of imprecision in the dating. Comparisons of the Moulton Pond results with late-glacial pollen sequences elsewhere in eastern United States and adjacent Canada reveal a lack of synchroneity in vegetational changes casting doubt on claims of major broad-scale climatic shifts over the entire area.

The tundra period at Moulton Pond ended with a transition of a few hundred years to partly open, relatively xeric forests of low diversity dominated by white pine, oak, and birch trees. There was no intervening boreal forest. In the postglacial period the vegetation was continually changing, including in the early portion a series of immigrations of temperate tree taxa which later became important in the forests. The transient nature of these assemblages is further indicated by their differences from the closest modern analogs. From about 7100 y. a. until settlement by Europeans 200 y. a., the forests were closed. A major decline of conifers centering about 4700 y. a. was followed by maxima of mesic hardwoods about a thousand years later. In the most recent 2000 yr, the pollen record suggests greater environmental severity, evidenced by increasing spruce. But for the entire postglacial period, the closest modern vegetational analogs are all in the conifer-hardwood region. Much of the postglacial pollen sequence is inexplicable in climatic terms, as evidenced by nonsynchronous behavior of hemlock and beech.

The pollen influx diagram is useful for distinguishing tundra from forest, but for the postglacial period it is difficult to interpret. Pollen influx data are strongly affected by shifts in the pattern of sedimentation in lakes. We propose that such shifts account for the major changes in influx in mid- and late-postglacial time at Moulton Pond and at Rogers Lake, Connecticut. This complicates the interpretation of influx data which otherwise are superior to percentage data.

The purpose of this discussion is to call attention to the presence at various times of large quantities of volcanic dust in the atmosphere. Remarkable visual effects from this dust may imply hitherto unconsidered problems in identifying alleged references to solar eclipses in African chronicles and oral traditions. Climatologist Hubert Lamb has compiled the data on volcanic eruptions and dust veils since 1500 AD and attempted to determine possible meteorological effects.

Contemporary notions of volcanic activity are predisposed to spectacular lava flows, which make more interesting journalism and greater popular interest. However, eruptions characterized by free-flowing lava –– conventionally termed Type A –– are relatively unimportant in the volcanic dust question. We are interested in so-called Type B events, usually violent explosions resulting from the inability of lava or steam to find convenient outlets. Such an explosion may inject huge quantities of dust and debris into the atmosphere, causing a wide variety of visual anomalies as they are carried around the world by high-altitude winds. If the dust veil is sufficiently dense it may even cause short-term alterations in weather patterns.

There are many biological macro-molecules such as nucleic acids, lipids, carbohydrates and proteins. While each of them plays a vital (and interesting) part in life but there is something special about the proteins. Proteins are the key link between the processes of information and replication that take place on a genetic level and the infrastructure of living features. Understanding the properties of proteins is the key to understanding the spark of the life. In this paper we describe our study of various electrical properties of protein when performing measurements at the nanoscale. To achieve this goal we designed and fabricated a nanoelectronic probe. This nano structure consists of four thin film layers. There are two conductive layers and an insulative layer in between. There is also a protective oxide layer as the top most layer. This layer is to prevent the exposure of conductive electrodes to the solution. Underneath the bottom electrode, there is another oxide layer, which can be a thermally grown oxide. This layer insulates the first electrode from the substrate. In this study, while we use non-specific detection of streptavidin protein as a proof of concept, we emphasize that the findings of this study can be extended to specific detection of target proteins, where in this case a specific probe molecule would also be immobilized on the sensor surface.

Here we present the development of an array of electrical nano-biosensors in a microfluidic channel, called Nanoneedle biosensors. Then we present the proof of concept study for protein detection. A Nanoneedle biosensor is a real-time, label-free, direct electrical detection platform, which is capable of high sensitivity detection, measuring the change in ionic current and impedance modulation, due to the presence or reaction of biomolecules such as proteins or nucleic acids. We show that the sensors which have been fabricated and characterized for the protein detection. We have functionalized Nanoneedle biosensors with receptors specific to a target protein using physical adsorption for immobilization. We have used biotinylated bovine serum albumin as the receptor and sterptavidin as the target analyte. The detection of streptavidin binding to the receptor protein is also presented.

With the aid of negative dielectrophoresis (nDEP) force in conjunction with shear force and at an optimal sodium hydroxide (NaOH) concentration we demonstrated a switch-like functionality to elute immuno-bound beads from the surface. At an optimal flow rate and NaOH concentration, nDEP turned on results in bead detachment, whereas when nDEP is off, the beads remain attached. This platform offers the potential for performing a bead-based multiplexed immunoassay where in a single channel various regions are immobilized with a different antibody, each targeting a different antigen. As a proof of concept we demonstrated the ability of nDEP to provide this switching behavior in a singleplex assay for the interactions that were in the same order of magnitude in strength as typical antibody-antigen interactions.