Picosecond Dynamic Heterogeneity, Hopping and Johari-Goldstein Relaxation in Glassforming Liquids

We show that incoherent quasi-elastic neutron scattering (QENS) from molecular liquids reveals a two-state dynamic heterogeneity on a 1 ps timescale, where molecules are either highly confined or are free to undergo relatively large excursions. Data ranging from deep in the glassy state to well above the melting point allows us to observe temperature-dependent population levels and exchange between these two states. A simple physical picture emerges from this data, combined with published work, that provides a mechanism for "hopping" and for the Johari-Goldstein ($\beta_{JG}$) relaxation, and allows us to accurately calculate the diffusion coefficient, $D_T$, and characteristic times for $\alpha$, and $\beta_{JG}$ relaxations from ps timescale neutron data.Comment: 5 pages, 4 figure

VALIDATING COOPERATIVE SYSTEMS SIMULATION AND REMODELING FOR PUMP COVER DESIGN AND MANUFACTURING IN A VIRTUAL ENTERPRISE

In order to integrate the manufacturing systems in virtual environment some changes must be made in manufacturing systems architecture. To support this environment, the basic infrastructure for the enterprise must to consider two main modules: The Internal Module, that represents the autonomous unit of a particular company and includes the manufacturing system, the complete structure of the company information (databases, information system etc.) and all the decision making processes;virtual enterprise, manufacturing systems, remodeling, simulation, cooperative systems

Histological coherent Raman imaging: a prognostic review

Histopathology plays a central role in diagnosis of many diseases including solid cancers. Efforts are underway to transform this subjective art form to an objective and quantitative science. Coherent Raman imaging (CRI), a label-free imaging modality with sub-cellular spatial resolution and molecule-specific contrast possesses characteristics which could support the qualitative-to-quantitative transition of histopathology. In this work we briefly survey major themes related to modernization of histopathology, review applications of CRI to histopathology and, finally, discuss potential roles for CRI in the transformation of histopathology that is already underway

The determination of the global average OH concentration using a deuteroethane tracer

It is proposed to measure the decreasing global concentration of an OH reactive isotopic tracer, G sub 2 D sub 6, after its introduction into the troposphere in a manner to facilitate uniform global mixing. Analyses at the level of 2 x 10 to the -19th power fraction, corresponding to one kg uniformly distributed globally, should be possible by a combination of cryogenic absorption techniques to separate ethane from air and high sensitivity isotopic analysis of ethane by mass spectrometry. Aliquots of C sub 2 D sub 6 totaling one kg would be introduced to numerous southern and northern latitudes over a 10 day period in order to achieve a uniform global concentration within 3 to 6 months by the normal atmospheric circulation. Then samples of air of 1000 l (STP) would be collected periodically at a tropical and temperate zone location in each hemisphere and spiked with a known amount of another isotopic species of ethane, C-13 sub 2 H sub 6, at the level of 10 to the -11th power mole fraction. After separation of the ethanes from air, the absolute concentration of C sub 2 D sub 6 would be analyzed using the Argonne 100-inch radius mass spectrometer

Th17, intestinal microbiota and the abnormal immune response in the pathogenesis of celiac disease

Celiac disease (CD) is an autoimmune enteropathy induced by the ingestion of gluten in genetically predisposed individuals who carry the HLA-DQ2 or -DQ8 alleles. The immune response is abnormal in celiac disease with small intestinal epithelial damage via CD8+CD4- intraepithelial lymphocytes. The etiology is multifactorial involving genetic and environmental factors, an abnormal immune response, and intestinal dysbiosis. The innate and acquired T-cell mediated immunity play important roles in the pathogenesis of this disease, particularly CD4+ Th17 cells, which have been shown to have critical functions in host defense against bacterial pathogens and in the inflammatory responses to deamidated gluten peptides. We review what is known about the interaction between immune system and intestinal microbiota in the pathogenesis of celiac disease

Economic Commentary: Rent Control-Who Pays the Rent

According to a recent government report, over 200 U.S. cities, including Boston, have some form of rent control. Although rent control is now a national phenomenon, many people are unfamiliar with it. What is rent control, how does it work, why is it so widely used and who really pays the rent