Children at risk : their phonemic awareness development in holistic instruction

Includes bibliographical references (p. 17-19

A statistical study of variation in the catch of plankton nets

Staternent of the Problern.----In a previous communication, Winsor and Walford (1936) analyzed the results of repeated vertical hauls of different types of plankton nets, making use of data available in the literature. They concluded that the observed results could be accounted for reasonably well on the assumptions that (a) the organisms were randomly distributed in the medium and (b) that the volume of medium effectively sampled varied from haul to haul. From this result it follows that as the total catch is increased (as by increasing the net size) the reliability of a population estimate is ultimately limited by variation in volume sampled; and that where such conditions hold, it is useless to attempt greater accuracy by increasing either the total catch or the fraction counted much beyond the point where 100 organisms of the kind in question are counted

Wind-driven mixing causes a reduction in the strength of the continental shelf carbon pump in the Chukchi Sea

The Chukchi Sea is thought to be a globally important sink of atmospheric CO2 due to the summertime drawdown of surface pCO2 by phytoplankton and subsequent shelf-to-basin transport of CO2-enriched subsurface waters into the upper halocline of the Arctic Ocean. Here we show that annually occurring storm-induced mixing events during autumn months disrupt water column stratification and stir up remineralized carbon from subsurface waters to the surface, leading to CO2 outgassing to the atmosphere. Our analysis provides a new understanding of the dynamics of carbon cycling in the region and suggests that late season wind events are strong and frequent enough to significantly decrease the carbon sink strength of the Chukchi Sea on a scale of relevance to the global carbon cycle. These results highlight the importance of obtaining data with more complete seasonal and spatial coverage in order to accurately constrain regional to basin-scale carbon flux budgets

Condensation of microturbulence-generated shear flows into global modes

In full flux-surface computer studies of tokamak edge turbulence, a spectrum of shear flows is found to control the turbulence level and not just the conventional (0,0)-mode flows. Flux tube domains too small for the large poloidal scale lengths of the continuous spectrum tend to overestimate the flows, and thus underestimate the transport. It is shown analytically and numerically that under certain conditions dominant (0,0)-mode flows independent of the domain size develop, essentially through Bose-Einstein condensation of the shear flows.Comment: 5 pages, 4 figure

Linking the 8.2 ka Event and its Freshwater Forcing in the Labrador Sea

The 8.2 ka event was the last deglacial abrupt climate event. A reduction in the Atlantic meridional overturning circulation (AMOC) attributed to the drainage of glacial Lake Agassiz may have caused the event, but the freshwater signature of Lake Agassiz discharge has yet to be identified in (delta)18O of foraminiferal calcite records from the Labrador Sea, calling into question the connection between freshwater discharge to the North Atlantic and AMOC strength. Using Mg/Ca-paleothermometry, we demonstrate that approx. 3 C of near-surface ocean cooling masked an 1.0 % decrease in western Labrador Sea (delta)18O of seawater concurrent with Lake Agassiz drainage. Comparison with North Atlantic (delta)18O of seawater records shows that the freshwater discharge was transported to regions of deep-water formation where it could perturb AMOC and force the 8.2 ka event

Pressure Induced Topological Phase Transitions in Membranes

Some highly unusual features of a lipid-water liquid crystal are revealed by high pressure x-ray diffraction, light scattering and dilatometric studies of the lamellar (bilayer $L_{\alpha}$) to nonlamellar inverse hexagonal ($H_{II}$) phase transition. (i) The size of the unit cell of the $H_{II}$ phase increases with increasing pressure. (ii) The transition volume, $\Delta V_{bh}$, decreases and appears to vanish as the pressure is increased. (iii) The intensity of scattered light increases as $\Delta V_{bh}$ decreases. Data are presented which suggest that this increase is due to the formation of an intermediate cubic phase, as predicted by recent theoretical suggestions of the underlying universal phase sequence.Comment: 12 pages, typed using REVTEX 2.

Evidence for the Gompertz Curve in the Income Distribution of Brazil 1978-2005

This work presents an empirical study of the evolution of the personal income distribution in Brazil. Yearly samples available from 1978 to 2005 were studied and evidence was found that the complementary cumulative distribution of personal income for 99% of the economically less favorable population is well represented by a Gompertz curve of the form $G(x)=\exp [\exp (A-Bx)]$, where $x$ is the normalized individual income. The complementary cumulative distribution of the remaining 1% richest part of the population is well represented by a Pareto power law distribution $P(x)= \beta x^{-\alpha}$. This result means that similarly to other countries, Brazil's income distribution is characterized by a well defined two class system. The parameters $A$, $B$, $\alpha$, $\beta$ were determined by a mixture of boundary conditions, normalization and fitting methods for every year in the time span of this study. Since the Gompertz curve is characteristic of growth models, its presence here suggests that these patterns in income distribution could be a consequence of the growth dynamics of the underlying economic system. In addition, we found out that the percentage share of both the Gompertzian and Paretian components relative to the total income shows an approximate cycling pattern with periods of about 4 years and whose maximum and minimum peaks in each component alternate at about every 2 years. This finding suggests that the growth dynamics of Brazil's economic system might possibly follow a Goodwin-type class model dynamics based on the application of the Lotka-Volterra equation to economic growth and cycle.Comment: 22 pages, 15 figures, 4 tables. LaTeX. Accepted for publication in "The European Physical Journal B

Deep-water flow over the Lomonosov Ridge in the Arctic Ocean

Author Posting. © American Meteorological Society, 2005. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 35 (2005): 1489–1493, doi:10.1175/JPO2765.1.The Arctic Ocean likely impacts global climate through its effect on the rate of deep-water formation and the subsequent influence on global thermohaline circulation. Here, the renewal of the deep waters in the isolated Canadian Basin is quanitified. Using hydraulic theory and hydrographic observations, the authors calculate the magnitude of this renewal where circumstances have thus far prevented direct measurements. A volume flow rate of Q = 0.25 ± 0.15 Sv (Sv ≡ 106 m3s−1) from the Eurasian Basin to the Canadian Basin via a deep gap in the dividing Lomonosov Ridge is estimated. Deep-water renewal time estimates based on this flow are consistent with 14C isolation ages. The flow is sufficiently large that it has a greater impact on the Canadian Basin deep water than either the geothermal heat flux or diffusive fluxes at the deep-water boundaries.Financial support was provided to P. Winsor from NSF OPP- 0352628

Expanding Efficiency: Women\u27s Communication in Engineering

As engineering fields strive to be more inclusive of women, focusing on perceptions of women\u27s work is vital to understanding how women can succeed and the limitations they may face. One area in need of more attention is the connection between communication and women\u27s experiences in engineering. This article examines the gendered nature of writing labor in engineering, focusing on case studies of three women who were able to use writing effectively, yet how communication emerged as a gendered form of labor subject to gendered perceptions. While these women\u27s communication skills led to professional success, their association with writing echoes a historical division, where writing is viewed as less valuable than technical knowledge. This division has the potential to disadvantage women who are asked to take on more writing-related tasks. In addition, their writing and communication are subject to gendered perceptions of being ‘chatty’ or blunt rather than effective or efficient. Articulating these perceptions and attitudes can lead to a breakdown of the binary between writing and technical labor as well as appropriately valuing the contributions women make in engineering through writing