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Light intensity (I) fluctuates rapidly and is the most important environmental factor affecting photosynthesis. Accurate characterization of light-response curve of leaf-scale photosynthesis (PN-I curve) is fundamental for understanding PN-I relations at the whole-plant and ecosystem scales. A robust PN-I model should be accurate in reproducing PN-I curves over light-limited, light-saturated, and photoinhibitory I levels, and ideally returning key quantitative traits defining the curves, including initial slope of increase (a), dark respiration rate (RD), the maximum net photosynthetic rate (PNmax), and the corresponding saturation intensity (Isat). We need to improve a model reproduction of (1) PN-I responses over low I levels and (2) the widely reported decline of PN at photoinhibitory I levels. Our observation-modelling comparison, shown by the widely used non-rectangular hyperbolic model, led to (1) underestimation of RD, (2) overestimation of PNmax, and (3) failure in reproducing the photoinhibitory response when I surpassed the cultivar-specific Isat. In contrast, our model addressed the above limitations extremely well. The results highlighted the accuracy and robustness of our model, especially in (1) returning key traits defining the curve and (2) reproducing the curve over both low [i.e., 0-50 µmol(photon) m-2 s-1] and photoinhibitory I levels (i.e., beyond Isat). [ABSTRACT FROM AUTHOR]

The structural patterns of periodic cellular materials play an important role in their properties. Here, we investigate how these patterns transform dramatically under external stimuli in simple periodic cellular structures that include a nanotube bundle and a millimeter-size plastic straw bundle. Under gradual hydrostatic straining up to 20%, the cross-section of the single walled carbon nanotube bundle undergoes several pattern transformations, while an amazing new hexagram pattern is triggered from the circular shape when the strain of 20% is applied suddenly in one step. Similar to the nanotube bundle, the circular plastic straw bundle is transformed into a hexagonal pattern on heating by conduction through a baseplate but into a hexagram pattern when heated by convection. Besides the well-known elastic buckling, we find other mechanisms of pattern transformation at different scales; these include the minimization of the surface energy at the macroscale or of the van der Waals energy at the nanoscale and the competition between the elastic energy of deformation and either the surface energy at the macroscale or the van der Waals energy at the nanoscale. The studies of the pattern transformations of periodic porous materials offer new insights into the fabrication of novel materials and devices with tailored properties. [ABSTRACT FROM AUTHOR]

Two methods are presented to predict the effective conductivities of heterogeneous media containing discretely suspended particles. The particles have either graded anisotropy or a graded anisotropic interphase. A differential replacement procedure based on an energy equivalency condition is presented first to replace the graded anisotropic constituents by equivalent homogeneous isotropic particles. This allows many approximate schemes to be used to predict the effective conductivities of the heterogeneous media containing graded anisotropic constituents from the conductivity of the equivalent homogeneous particles. Next, the optimized upper and lower bounds on the effective conductivities of these heterogeneous media are presented by introducing comparison materials. It is shown that the DRP predictions are within these bounds for the considered media. [ABSTRACT FROM AUTHOR]

Investigates the characteristics of silicon-doped indium (In)-aluminum (Al)-arsenic (As) layers as a function of silicon doping. Application of low-temperature photoluminescence and Raman spectroscopy; Bond-energy difference between In-As and Al-As; Cause of reduction in the donor binding energy at high doping levels.

OBJECTIVE: Abnormal activation of androgen receptor (AR) signaling pathway is a critical pathogenic mechanism and therapeutic target for prostate cancer (PCa). The CA916798 is a tumor-associated gene and may be regulated by the androgen-AR pathway. This study aims to investigate the function of CA916798 in the growth and metastasis of androgen- dependent PCa cells. MATERIALS AND METHODS: CA916798 expression in PCa cell lines was investigated. LNCap cells were divided into 4 groups: LNCap, LNCap+ Dihydrotestosterone (DHT), LNCap+ DHT+siCA916798, and LNCap+DHT+siRA group. CA916798 expressions in LNCap cells treated with siCA917698 or siAR were examined. The viability, apoptosis, migration, and invasion of PCa cells were examined. Dual luciferase and ChIP assays were used to examine the interaction between the AR and CA916798. RESULTS: Endogenous CA916798 mRNA levels in PC3 cells were significantly higher than those in LNCap cells (p < 0.05). However, CA916798 was androgen-sensitive in LNCap cells, but not in PC-3 cells. Dual luciferase and ChIP assays showed that AR could specifically bind to the promoter regions of the CA916798. Knockdown of CA916798 (LNCap+DHT+si- CA916798) and AR (LNCap+DHT+siAR) resulted in decreased cell viability, migration, and invasion, while it induced apoptosis and G1 cell cycle arrest in LNCap cells. CONCLUSIONS: DHT could initiate the transcription of CA916798, which further mediates the androgen-AR signaling pathway-dependent cell growth and metastasis of the prostate cancer cell line LNCap. [ABSTRACT FROM AUTHOR]

Naphthenic acids, separated from a bitumen and a furfural extract by extraction with solution of ammonia in ethylene glycol, have been added to the bitumen for the investigation of the influence on its properties. The results indicate that the ductility of the bitumen decreased and its penetration increased after mixed with these naphthenic acids. The data obtained also show that the naphthenic acids of furfural extract with lower molecular weight have greater impact on the ductility of bitumen than the naphthenic acids of bitumen with higher molecular weight. [ABSTRACT FROM AUTHOR]