Utilization of Shredded Rubber Tires for Cement-Stabilized Soft Clays

Tire-soil mixtures can be used as good construction materials in many geotechnical engineering applications such as pavement foundations, lightweight fill in road embankments and lightweight backfill behind retaining walls. This paper describes research undertaken to investigate experimentally the impact of shredded rubber tires as reinforcing material on the mechanical properties of cement-stabilized soft clay, in terms of strength and stiffness. A series of laboratory experiments are carried out on cement-stabilized clay mixed with several portions of shredded rubber tires of sizes 440 m and 4 mm. The tests conducted include compaction, unconfmed compression strength and indirect tensile strength. The results demonstrate that the use of shredded rubber tires has a potential in enhancing the ductility of cement-stabilized soft clay but decreases stiffness and ultimate resistance

Augmenting the Calvin-Benson-Bassham cycle by a synthetic malyl-CoA-glycerate carbon fixation pathway.

The Calvin-Benson-Bassham (CBB) cycle is presumably evolved for optimal synthesis of C3 sugars, but not for the production of C2 metabolite acetyl-CoA. The carbon loss in producing acetyl-CoA from decarboxylation of C3 sugar limits the maximum carbon yield of photosynthesis. Here we design a synthetic malyl-CoA-glycerate (MCG) pathway to augment the CBB cycle for efficient acetyl-CoA synthesis. This pathway converts a C3 metabolite to two acetyl-CoA by fixation of one additional CO2 equivalent, or assimilates glyoxylate, a photorespiration intermediate, to produce acetyl-CoA without net carbon loss. We first functionally demonstrate the design of the MCG pathway in vitro and in Escherichia coli. We then implement the pathway in a photosynthetic organism Synechococcus elongates PCC7942, and show that it increases the intracellular acetyl-CoA pool and enhances bicarbonate assimilation by roughly 2-fold. This work provides a strategy to improve carbon fixation efficiency in photosynthetic organisms

A Frequency-Reconfigurable Antenna With 1-mm Nonground Portion for Metal Frame and Full-Display Screen Handset Applications Using Mode Control Method

A frequency-reconfigurable antenna featuring four integrated switches for metal-frame and full-display screen handset applications is proposed in this paper. To achieve full-display aesthetics, the nonground portion of the proposed antenna is reduced to only 1 mm, making it impossible to formulate additional parasitic strips to enhance the bandwidth and radiation efficiency of the antenna. Four switches are employed in conjunction with the devised antenna to excite five resonant modes using the mode control method (MCM) to operate from 699 to 960 MHz and from 1710 to 2690 MHz. The proposed antenna is designed by employing several peripheral metallic components, such as steel sheet, USB, speaker box, and full-display screen into consideration, which enables the overall structure to be much closer to a practical smartphone environment. A prototype was fabricated and measured. The experimental results confirm that the proposed antenna features radiation efficiency from 30% to 55% for metal-frame and full-display screen handset applications.11Ysciescopu

Effects of CD2-associated protein deficiency on amyloid-β in neuroblastoma cells and in an APP transgenic mouse model

BACKGROUND: CD2-associated protein (CD2AP) is an SH3-containing scaffold adaptor protein which regulates the actin cytoskeleton. Recently, CD2AP was identified as a genetic risk factor for Alzheimer’s disease (AD) by several genome-wide association studies. One of the hallmarks of AD is the accumulation of aggregated forms of Amyloid-β (Aβ) in the brain. In humans, CD2AP AD susceptibility locus (rs9349407) is associated with an increased plaque burden. Aβ production is highly regulated by endocytosis and is influenced by lysosomal function. Lysosomal trafficking is influenced by CD2AP. In this study, we decreased CD2AP levels in N2a neuroblastoma cultures and PS1APP mice and analyzed Aβ levels and plaque burden. RESULTS: Our data show that suppressing CD2AP expression using shRNA in N2a-APP695 cells results in decreased cell membrane amyloid precursor protein, decreased Aβ release and a lower Aβ(42)/Aβ(40) ratio. CD2AP protein is expressed in the brain as detected by western blot, and the expression level is dependent on gene dosage. In 1-month old PS1APP mice, complete loss of CD2AP in brain resulted in a decreased Aβ(42)/Aβ(40) ratio in brain tissue lysates while there was no effect on Aβ deposition or accumulation in PS1APP mice expressing one copy of CD2AP. CONCLUSION: CD2-Associated Protein affects Aβ levels and Aβ(42)/Aβ(40) ratio in vitro. The effect of CD2-Associated Protein on Aβ metabolism is subtle in vivo

Production of the neutral toppion at the e gamma colliders

In the framework of topcolor-assisted technicolor(TC2) model, we study a neutral toppion production process $e^{-}\gamma\to e^{-}\Pi^{0}_{t}$ in this paper. Our results show that the production cross section of $e^{-}\gamma\to e^{-}\Pi^{0}_{t}$ can reach the level of several tens fb, and over $10^{3}$ neutral toppion events can be produced in the planned $e^+e^-$ linear colliders each year. Therefore, such a toppion production process provides us a unique chance to detect toppion events and test the TC2 model. On the other hand, the cross section of $e^{-}\gamma\to e^{-}\Pi^{0}_{t}$ is about one order of magnitude larger than those of some similar processes in SM and MSSM(i.e., $e^{-}\gamma\to e^{-}H$ in SM and $e^{-}\gamma\to e^{-}H^{0}(A^0,h^0)$ in MSSM). So, we can easily distinguish the neutral toppion from other neutral Higgs bosons in SM and MSSM.Comment: 12 pages, 4 figures, The paper has been accepted by Phys.Rev.

Symmetry Nonrestoration in a Gross-Neveu Model with Random Chemical Potential

We study the symmetry behavior of the Gross-Neveu model in three and two dimensions with random chemical potential. This is equivalent to a four-fermion model with charge conjugation symmetry as well as Z_2 chiral symmetry. At high temperature the Z_2 chiral symmetry is always restored. In three dimensions the initially broken charge conjugation symmetry is not restored at high temperature, irrespective of the value of the disorder strength. In two dimensions and at zero temperature the charge conjugation symmetry undergoes a quantum phase transition from a symmetric state (for weak disorder) to a broken state (for strong disorder) as the disorder strength is varied. For any given value of disorder strength, the high-temperature behavior of the charge conjugation symmetry is the same as its zero-temperature behavior. Therefore, in two dimensions and for strong disorder strength the charge conjugation symmetry is not restored at high temperature.Comment: 16 pages, 3 figure

Two lectures on color superconductivity

The first lecture provides an introduction to the physics of color superconductivity in cold dense quark matter. The main color superconducting phases are briefly described and their properties are listed. The second lecture covers recent developments in studies of color superconducting phases in neutral and beta-equilibrated matter. The properties of gapless color superconducting phases are discussed.Comment: 56 pages, 9 figures. Minor corrections and references added. Lectures delivered at the IARD 2004 conference, Saas Fee, Switzerland, June 12 - 19, 2004, and at the Helmholtz International Summer School and Workshop on Hot points in Astrophysics and Cosmology, JINR, Dubna, Russia, August 2 - 13, 200