Phenolic Phytoalexins in Rice: Biological Functions and Biosynthesis

Phytoalexins are inducible secondary metabolites possessing antimicrobial activity against phytopathogens. Rice produces a wide array of phytoalexins in response to pathogen attacks and environmental stresses. With few exceptions, most phytoalexins identified in rice are diterpenoid compounds. Until very recently, flavonoid sakuranetin was the only known phenolic phytoalexin in rice. However, recent studies have shown that phenylamides are involved in defense against pathogen attacks in rice. Phenylamides are amine-conjugated phenolic acids that are induced by pathogen infections and abiotic stresses including ultra violet (UV) radiation in rice. Stress-induced phenylamides, such as N-trans-cinnamoyltryptamine, N-p-coumaroylserotonin and N-cinnamoyltyramine, have been reported to possess antimicrobial activities against rice bacterial and fungal pathogens, an indication of their direct inhibitory roles against invading pathogens. This finding suggests that phenylamides act as phytoalexins in rice and belong to phenolic phytoalexins along with sakuranetin. Phenylamides also have been implicated in cell wall reinforcement for disease resistance and allelopathy of rice. Synthesis of phenolic phytoalexins is stimulated by phytopathogen attacks and abiotic challenges including UV radiation. Accumulating evidence has demonstrated that biosynthetic pathways including the shikimate, phenylpropanoid and arylmonoamine pathways are coordinately activated for phenolic phytoalexin synthesis, and related genes are induced by biotic and abiotic stresses in rice.     

Effects of solidification structure on fatigue crack initiation and fatigue strength in Al−Si−Mg cast alloys

Rotating-bending uniaxial fatigue tests and micro-fatigue crack initiation tests were carried out using a permanent mold cast (PMC) and semi-solid die cast (SDC) with Al−7%Si−0.35%Mg composition in order to examine the relationship between solidification structures and fatigue behaviors. The crack length was measured using a replication method. Fatigue strength was improved in SDC, which was almost consistent with the predicted fatigue strength using the size of Si particle cluster. Resistance to fatigue crack initiation and fatigue strength were improved in SDC owing to the finer Si cluster and to higher ultimate tensile strength. Fatigue crack in PMC was preferentially initiated at pores. For SDC, the fatigue crack was initiated at the Si particle/matrix interface, and then sucessively grew along eutectic cell boundaries.     

On the selective counting of third-order products

A practical and efficient method is presented for the counting of third-order products generated by an arbitrary number of carriers with arbitrary power spectral shapes. In particular, three selective counting procedures (i.e. sorting by position, sorting by position and group, and sorting by position, group, and kind) are introduced in a systemic way, based upon a discrete third-order Volterra model. The advantage of the counting algorithm is that (1) the algorithm provides the exact counting of third-order products of all eleven possible groups; (2) the counting process requires only two multiplications for the selective counting of third-order products at each position, and the algorithm, which is thus efficient, can be easily implemented     

Higher order eigensensitivity analysis of damped systems with repeated eigenvalues

A simplified method for the computation of first-, second- and higher-order derivatives of eigenvalues and eigenvectors associated with repeated eigenvalues is presented. Adjacent eigenvectors and orthonormal conditions are used to compose an algebraic equation. The algebraic equation which is developed can be used to compute derivatives of eigenvalues and eigenvectors simultaneously. Since the coefficient matrix in the proposed algebraic equation is non-singular, symmetric and based on N-space, it is numerically stable and very efficient compared to previous methods. To verify the efficiency of the proposed method, the finite element model of the cantilever beam and a mechanical system in the case of a non-proportionally damped system are considered.     

Anti-diabetic effects of mulberry (Morus alba L.) branches and oxyresveratrol in streptozotocin-induced diabetic mice

Food Science and Biotechnology - Despite with accumulating evidences on the anti-diabetic effects of mulberry branch (MB), the major active component for the activity has not been known. Oral...     

A Strategic Approach for Managing Oil and Gas Assets

The global oil market is experiencing a structural shift. Faced with a rapid price decline, large oil-producing countries had decided to protect their market share, with the hopes of permanently removing expensive supply from the market. Meanwhile, the ability of the US shale oil producers to respond quickly to positive price signals puts downward pressure on prices. On the demand side, advances in renewable technology and the continued effort to curb consumption of fossil fuel conspire to inhibit long-run growth.¹ These factors suggest that the current down-cycle may continue for an extended period of time or even invoke another down-cycle.     

Fault location algorithm for cross-bonded cables using the singularity of the sheath impedance matrix

This paper proposes a fault location algorithm for cross-bonded cables. The algorithm uses nonlinear equations that describe the voltage drops between both ends of core conductors and sheaths in terms of the phase voltages and currents of both the local and remote ends. Arranging these equations about the sheath currents yields a sheath impedance matrix, which is singular independently of the fault distance. Due to this singularity, the equations have no solution or an infinite number of solutions. The proposed algorithm finds the condition for which a solution to the equations exists. Since the equation of the condition is linear and explicit, the fault location can be found easily. Test results indicate that the algorithm accurately estimates the fault distance regardless of fault impedance, fault type, and fault section.     

Fabrication and characterization of eco-friendly functional wallpaper using nonmetallic minerals

The effects of amounts and particle size of nonmetallic minerals on the rheological behavior of the slurry and microstructure evolution of an eco-friendly functional wallpaper were investigated to optimize preparation parameters. Mixed binder system was used to prepare the wallpaper. Nonmetallic minerals such as TiO₂, CaCO₃, illite, pearl, and small amounts of graphite were mixed with the binder and then ball milled for 12 h. The particle size of the starting materials was controlled by the milling process, showing a significant reduction in particle size. Mixed slurries coated on base paper (substrate) were dried and pressed at 150 °C, forming seven layers. The reduced particle size increases the amounts of the nonmetallic minerals in the slurry, which causes an increase in viscosity and inhibits powder sedimentation. Despite the increase in the amounts of nonmetallic minerals, the nonmetallic minerals are homogeneously dispersed, as confirmed by microstructure and EDS mapping. The nonmetallic minerals provide the wallpaper with eco-friendly functions such as unit-infrared emission and antifungal ability, and improve the deodorization ratio and decrease the emission ratio of TVOC and HCHO compared with conventional wallpaper.     

Effect of temperature on the performance of a biofilter inoculated withPseudomonas putida to treat waste-air containing ethanol

The microbes ofPseudomonas putida (KCTC1768) were fixed on the biofilter-packing media comprising an equivolume mixture of granular activated carbon (GAC) and compost, by recycling the liquid medium containing incubatedPseudomonas putida (KCTC1768). A biofilter experiment was performed to observe its transient behavior under the operating condition of 2,180 ppmv of ethanol-inlet concentration and 158 g/m³/h of ethanol-inlet load for the five consecutive temperature-stages of operation ranging from 25 °C to 40 °C. For the five temperaturestages of operation their removal efficiencies were measured and were compared with each other. The optimum operating temperature of the biofilter turned out to beca. 30 °C, which was consistent with the previous experimental result of Lim and Park. However, the optimum incubation-temperatures ofPseudomonas putida (KCTC1768) and the equivalent (i.e., NCIMB8858) were announced to be of 26 °C and 25 °C by Korea Collection for Type Cultures (KCTC) and National Collections of Industrial, Food and Marine Bacteria (NCIMB), respectively. It was also confirmed by the experiment in which the microbes were incubated in the same liquid medium as in the previous work of Lim and Park at temperature ranging from 20 °C to 40 °C and their growth rates were subsequently measured. Thus, the optimum operating temperature of a biofilter inoculated withPseudomonas putida (KCTC 1768) was proved to be 30 °C, which was higher than its optimum incubation-temperature byca. 5 °C     

PCB-compatible optical interconnection using 45/spl deg/-ended connection rods and via-holed waveguides

In this paper, a new architecture for a chip-to-chip optical interconnection system is demonstrated that can be applied in a waveguide-embedded optical printed circuit board (PCB). The experiment used 45/spl deg/-ended optical connection rods as a medium to guide light paths perpendicularly between vertical-cavity surface-emitting lasers (VCSELs), or photodiodes (PDs) and a waveguide. A polymer film of multimode waveguides with cores of 100/spl times/65 /spl mu/m was sandwiched between conventional PCBs. Via holes were made with a diameter of about 140 /spl mu/m by CO/sub 2/-laser drilling through the PCB and the waveguide. Optical connection rods were made of a multimode silica fiber ribbon segment with a core diameter of 62.5 and 100 /spl mu/m. One end of the fiber segment was cut 45/spl deg/ and the other end 90/spl deg/ by a mechanical polishing method. These fiber rods were inserted into the via holes formed in the PCB, adjusting the insertion depth to locate the 45/spl deg/ end of rods near the waveguide cores. From this interconnection system, a total coupling efficiency of about -8 dB was achieved between VCSELs and PDs through connection rods and a 2.5 Gb/s /spl times/ 12-ch data link demonstrated through waveguides with a channel pitch of 250 /spl mu/m in the optical PCB.