A Preliminary Analysis of the Supply and Demand for Middle School Mathematics and Science Teachers in Virginia

Virginia Colleges and Universities have a major challenge to produce educated elementary and middle school students. The magnitude of this challenge can be measured by studying the number of current teachers in each grade in Virginia and the anticipated retirements and departures from the profession for other reasons. The new licensure requirements have their biggest impact for the preparation of middle school teachers since middle school teachers will no longer be able to receive general middle school certification

The symbolic model for algebra : functions and mechanisms

The symbolic mode of reasoning in algebra, as it emerged during the sixteenth century, can be considered as a form of model-based reasoning. In this paper we will discuss the functions and mechanisms of this model and show how the model relates to its arithmetical basis. We will argue that the symbolic model was made possible by the epistemic justification of the basic operations of algebra as practiced within the abbaco tradition. We will also show that this form of model-based reasoning facilitated the expansion of the number concept from Renaissance interpretations of number to the full notion of algebraic numbers

Gaseous elemental and reactive mercury in Southern New Hampshire

We conducted measurements of Hg<sup>0</sup> and RGM at two inland sites, Thompson Farm (TF) and Pac Monadnock (PM), and a marine site (Appledore Island (AI)) from the UNH AIRMAP observing network in New Hampshire in 2007. Measurements of other important trace gases and meteorological variables were used to help understand influences on the atmospheric Hg budget in New England. Seasonal variation in both species observed at TF and PM is attributable to such factors as seasonal variation in deposition strength, meteorological conditions and biogenic emissions. Hg<sup>0</sup> and RGM varied diurnally at TF, particularly in spring, following the trend in air temperature and <i>j</i>NO<sub>2</sub> and suggesting photochemical production of RGM. The diurnal patterns of Hg<sup>0</sup> and RGM at AI during summer were nearly opposite in phase, with Hg<sup>0</sup> decreasing through late afternoon, suggesting more significant photochemical oxidation of Hg<sup>0</sup> to RGM in the marine environment, likely due to the presence of marine halogen compounds. A significant relationship of RGM with SO<sub>2</sub> at TF suggests a strong contribution of RGM from anthropogenic sources. Significant levels of halogen compounds measured at TF in previous studies, as well as similar Hg<sup>0</sup> levels and Hg<sup>0</sup>-CO ratios at TF and AI may suggest that similar air masses are prevalent at these sites

Bear Lake It\u27s Fish and Fishing

Bear Lake is an old lake. The lake basin was form ed during the growth of the surround ing mountains; since that time, a lake has been present whenever the climate has been wet enough, but it has probably completely dried up during very dry periods

Oceanic influence on atmospheric mercury at coastal and inland sites: a springtime noreaster in New England

Continuous measurements of elemental (Hg<sup>0</sup>) and reactive mercury were conducted at two sites in New Hampshire during a powerful April 2007 noreaster. During the most intense period of the storm, enhancements of ~30–50 ppqv in Hg<sup>0</sup> were observed at a coastal and a high elevation inland site. This enhancement occurred simultaneously with elevated mixing ratios of three marine tracers, CH<sub>3</sub>I, CH<sub>2</sub>Br<sub>2</sub> and CHBr<sub>3</sub>. These observations suggest a marine source of Hg<sup>0</sup>, possibly outgassing from the ocean surface during strong turbulence. The Hg<sup>0</sup> enhancement observed 100 km inland suggests that the impact of coastal storms on terrestrial Hg cycling may not be limited to near-shore environments. Combining Hg<sup>0</sup> and marine tracer measurements during the storm with estimates of oceanic tracer fluxes during previous strong storms yields an order-of-magnitude estimate of the oceanic source of Hg<sup>0</sup> during the storm (~7 ppqv h<sup>−1</sup>) which can account for the observed enhancement at the field sites

Excellence in the VP Navy

"Excellence in the VP Navy" is examined, first by providing the views of senior naval officers at the functional and operational wing level; then, four squadrons considered excellent by these senior officers are examined to determine how they go about achieving excellence.http://archive.org/details/excellenceinvpna00siglNAN

Factors underlying membrane potential-dependent and -independent fluorescence responses of potentiometric dyes in stressed cells: diS-C3(3) in yeast

AbstractThe redistribution fluorescent dye diS-C3(3) responds to yeast plasma membrane depolarisation or hyperpolarisation by Δψ-dependent outflow from or uptake into the cells, reflected in changes in the fluorescence maximum λmax and fluorescence intensity. Upon membrane permeabilisation the dye redistributes between the cell and the medium in a purely concentration-dependent manner, which gives rise to Δψ-independent fluorescence responses that may mimic Δψ-dependent blue or red shift in λmax. These λmax shifts after cell permeabilisation depend on probe and ion concentrations inside and outside the cells at the moment of permeabilisation and reflect (a) permeabilisation-induced Δψ collapse, (b) changing probe binding capacity of cell constituents (inverse to the ambient ionic strength) and (c) hampering of probe equilibration by the poorly permeable cell wall. At low external ion concentrations, cell permeabilisation causes ion outflow and probe influx (hyperpolarisation-like red shift in λmax) caused by an increase in the probe-binding capacity of the cell interior and, in the case of heat shock, protein denaturation unmasking additional probe-binding sites. At high external ion levels minimising net ion efflux and at high intracellular probe concentrations at the moment of permeabilisation, the Δψ collapse causes a blue λmax shift mimicking an apparent depolarisation

Pseudomorphic Growth of a Single Element Quasiperiodic Ultrathin Film on a Quasicrystal Substrate

An ultrathin film with a periodic interlayer spacing was grown by the deposition of Cu atoms on thefivefold surface of the icosahedral Al70 Pd21 Mn9 quasicrystal. For coverages from 5 to 25 monolayers, a distinctive quasiperiodic low-energy electron diffraction pattern is observed. Scanning tunneling microscopy images show that the in-plane structure comprises rows having separations of S = 4.5 �0.2 �A and L = 7.3 0.3 A, whose ratio equals � =1.618... within experimental error. The sequences of such row separations form segments of terms of the Fibonacci sequence, indicative of the formation of a pseudomorphic Cu film

CAPS-1 and CAPS-2 are essential synaptic vesicle priming proteins

SummaryBefore transmitter-filled synaptic vesicles can fuse with the plasma membrane upon stimulation they have to be primed to fusion competence. The regulation of this priming process controls the strength and plasticity of synaptic transmission between neurons, which in turn determines many complex brain functions. We show that CAPS-1 and CAPS-2 are essential components of the synaptic vesicle priming machinery. CAPS-deficient neurons contain no or very few fusion competent synaptic vesicles, which causes a selective impairment of fast phasic transmitter release. Increases in the intracellular Ca2+ levels can transiently revert this defect. Our findings demonstrate that CAPS proteins generate and maintain a highly fusion competent synaptic vesicle pool that supports phasic Ca2+ triggered release of transmitters