Resolving long-range spatial correlations in jammed colloidal systems using photon correlation imaging

We introduce a new dynamic light scattering method, termed photon correlation imaging, which enables us to resolve the dynamics of soft matter in space and time. We demonstrate photon correlation imaging by investigating the slow dynamics of a quasi two-dimensional coarsening foam made of highly packed, deformable bubbles and a rigid gel network formed by dilute, attractive colloidal particles. We find the dynamics of both systems to be determined by intermittent rearrangement events. For the foam, the rearrangements extend over a few bubbles, but a small dynamical correlation is observed up to macroscopic length scales. For the gel, dynamical correlations extend up to the system size. These results indicate that dynamical correlations can be extremely long-ranged in jammed systems and point to the key role of mechanical properties in determining their nature.Comment: Published version (Phys. Rev. Lett. 102, 085702 (2009)) The Dynamical Activity Mapsprovided as Supplementary Online Material are also available on http://w3.lcvn.univ-montp2.fr/~lucacip/dam/movies.ht

Reforestation of harvested Timberlands in Mississippi: Behavior and Attitudes of Non-Industrial, Private Forest Landowners

Southern forests play an increasingly important role in the timber economy as per capita demand for wood continues to expand. Moreover, harvest restrictions in the Pacific Northwest in the early 1990s shifted a large portion of United States demand for softwoods to the South. In Mississippi, most of the forestland is owned by non-industrial private forest (NIPF) landowners. Approximately 314,000 NIPF landowners control 66 percent of the state’s forestland base (Hartsell and London 1995). The sizable acreage of timberland held by NIPF landowners nationally and in-state underscores the importance of their role in the timber economy and weighs heavily in the supply of raw material to the state’s $11.4 billion forest products industry (Munn 1998)

Pairwise alignment incorporating dipeptide covariation

Motivation: Standard algorithms for pairwise protein sequence alignment make the simplifying assumption that amino acid substitutions at neighboring sites are uncorrelated. This assumption allows implementation of fast algorithms for pairwise sequence alignment, but it ignores information that could conceivably increase the power of remote homolog detection. We examine the validity of this assumption by constructing extended substitution matrixes that encapsulate the observed correlations between neighboring sites, by developing an efficient and rigorous algorithm for pairwise protein sequence alignment that incorporates these local substitution correlations, and by assessing the ability of this algorithm to detect remote homologies. Results: Our analysis indicates that local correlations between substitutions are not strong on the average. Furthermore, incorporating local substitution correlations into pairwise alignment did not lead to a statistically significant improvement in remote homology detection. Therefore, the standard assumption that individual residues within protein sequences evolve independently of neighboring positions appears to be an efficient and appropriate approximation

Factors Affecting Mississippi’s NIPF Landowners’ Reforestation Decisions

Non-industrial private forest (NIPF) landowners have played an increasingly important role in the nation\u27s timber economy. Nearly 70% of the forestland in the South is owned by NIPF landowners (Powell et al., 1994). In Mississippi alone, these landowners control approximately 66% of the state\u27s forestland base (Hartsell and London, 1995). Therefore, NIPF landowners are expected to provide a large portion of the state\u27s supply of timber. However, whether they do so depends largely on how their timberlands are managed. Forest management decisions of NIPF landowners can impact future timber supply due to the magnitude of their collective ownership

Comparison Between Regenerators and Non-Regenerators in Mississippi: A Discriminant Analysis

Nonindustrial private forestland (NIPF) landowners in Mississippi who recently harvested timber were surveyed to examine their regeneration behavior. Differences between regenerators and nonregenerators were investigated by looking at the different factors affecting reforestation decisions. A discriminant analysis was used to identify factors that were useful in differentiating between regenerators and nonregenerators. Ownership size; sociodemographic characteristics such as income, education, place of residence, and age; awareness of existing government incentive/assistance programs; and participation in educational programs were significant variables in differentiating between regenerators and nonregenerators. Landowners who own larger timberlands had a higher propensity to engage in regeneration activities after harvests. This also was true for landowners who had higher income levels and educational attainment, and were younger, city resident, and white. Landowners who were aware of existing government incentive/assistance programs and those who participated in educational programs also were more likely to participate in pine regeneration. Landowners in Mississippi considered both ecological and economic reasons as highly important considerations in their decision to regenerate. The belief that the land would reforest itself to pine naturally, the high cost of reforestation, and lack of information on reforestation options were top reasons cited by landowners for their decision not to regenerate. South. J. Appl. For. 28(4):189 –19

Gilt Edge Mine NPL Site Lawrence County, South Dakota: Final Report for the Climatic Evaluation (Deadwood and Lead, South Dakota)

This document serves as the final report for the climatic evaluation for the Ruby Gulch waste rock dump cap at the Gilt Edge Mine Site, Lawrence County, South Dakota (SD). This project was a collaborative effort between CDM Federal Programs Corporation and South Dakota State University (SDSU) under the U.S. Environmental Protection Agency (EPA) Region VIII response action contract. This report includes climatic analyses, raw weather data, and conclusions. In 1998 the Gilt Edge Mine near Deadwood, SD was abandoned and the reclamation of the mining site was halted. In 2000 SD requested that the EPA place the Gilt Edge Mine Site on the Superfund National Priorities List. SDSU through the South Dakota Agricultural Experiment Station (SDAES) was asked to assist the State of South Dakota and the EPA in the development of a remediation and revegetation plan for the abandoned Gilt Edge Mine Site.The objectives of this report are: 1. Detail and summarize the climatic information for the Gilt Edge Mine site area. 2. Analyze the data for application for soil and vegetation purposes 3. Archive the raw weather data from Deadwood and Lead, SD.This report highlights the available climatic data for two weather stations near the Gilt Edge Mine Superfund Site (GEMSS). The weather stations studied were Deadwood and Lead, SD. The weather station data for Deadwood covered the years 1943 through 1999 and the weather station data for Lead covered the years 1909 through 1999. The weather data summarized in this report include daily temperature (maximum, minimum, and average), monthly temperature (maximum, minimum, and average), numbers of days at critical warm and cold temperatures, precipitation (daily, daily maximums, 7-day maximums, monthly, monthly maximums, snowfall, and number of days per year at critical precipitation levels), growing degree days (40 OF basis), growing season length (28 OF basis). Deadwood, SD climatic data is summarized in Table A. Lead, SD climatic data is summarized in Table B

The Meissner effect in a strongly underdoped cuprate above its critical temperature

The Meissner effect and the associated perfect "bulk" diamagnetism together with zero resistance and gap opening are characteristic features of the superconducting state. In the pseudogap state of cuprates unusual diamagnetic signals as well as anomalous proximity effects have been detected but a Meissner effect has never been observed. Here we have probed the local diamagnetic response in the normal state of an underdoped La1.94Sr0.06CuO4 layer (up to 46 nm thick, critical temperature Tc' < 5 K) which was brought into close contact with two nearly optimally doped La1.84Sr0.16CuO4 layers (Tc \approx 32 K). We show that the entire 'barrier' layer of thickness much larger than the typical c axis coherence lengths of cuprates exhibits a Meissner effect at temperatures well above Tc' but below Tc. The temperature dependence of the effective penetration depth and superfluid density in different layers indicates that superfluidity with long-range phase coherence is induced in the underdoped layer by the proximity to optimally doped layers; however, this induced order is very sensitive to thermal excitation.Comment: 7 pages, 7 figures + Erratu