Recombinant yeast as a functional tool for understanding bitterness and cucurbitacin biosynthesis in watermelon (Citrullus spp.)

Cucurbitacins are a group of bitter‐tasting oxygenated tetracyclic triterpenes that are produced in the family Cucurbitaceae and other plant families. The natural roles of cucurbitacins in plants are probably related to defence against pathogens and pests. Cucurbitadienol, a triterpene synthesized from oxidosqualene, is the first committed precursor to cucurbitacins produced by a specialized oxidosqualene cyclase termed cucurbitadienol synthase. We explored cucurbitacin accumulation in watermelon in relation to bitterness. Our findings show that cucurbitacins are accumulated in bitter‐tasting watermelon, Citrullus lanatus var. citroides, as well as in their wild ancestor, C. colocynthis, but not in non‐bitter commercial cultivars of sweet watermelon (C. lanatus var. lanatus). Molecular analysis of genes expressed in the roots of several watermelon accessions led to the isolation of three sequences (CcCDS1, CcCDS2 and ClCDS1), all displaying high similarity to the pumpkin CpCPQ, encoding a protein previously shown to possess cucurbitadienol synthase activity. We utilized the Saccharomyces cerevisiae strain BY4743, heterozygous for lanosterol synthase, to probe for possible encoded cucurbitadienol synthase activity of the expressed watermelon sequences. Functional expression of the two sequences isolated from C. colocynthis (CcCDS1 and CcCDS2) in yeast revealed that only CcCDS2 possessed cucurbitadienol synthase activity, while CcCDS1 did not display cucurbitadienol synthase activity in recombinant yeast. ClCDS1 isolated from C. lanatus var. lanatus is almost identical to CcCDS1. Our results imply that CcCDS2 plays a role in imparting bitterness to watermelon. Yeast has been an excellent diagnostic tool to determine the first committed step of cucurbitacin biosynthesis in watermelon. Copyright © 2014 John Wiley & Sons, Ltd.     

Robust Designs for Quality Improvement

Taguchi's parameter design method allows one to make products or processes robust to uncontrollable noise factors. Recent research has focused on combining control and noise factors into a single array to model the response directly rather than relying on a performance measure such as the signal-to-noise ratio. Examination of control-by-noise interaction effects reveals control factor settings that dampen the effects of the noise factors. The objective of this paper is to propose modified cross-product designs for robustness improvement that enable one to reduce the experimentation costs while maximizing the amount of useful information.     

Long-range and energy-efficient optical networking for tiny sensors

Wireless Networks - Acquiring real time sensory data using remote swarms of tiny sensors depends on efficient wireless networking. Often, battery longevity of the sensors is a critical design...     

Optimisation of springback in bending processes using FEM simulation and response surface method

The aim of this work includes the springback optimisation of bending processes using the concept of experimental design and response surface methodology (RSM). The optimisation method includes two phases. The first involves the objective function prediction using design of experiments and response surface method, while the second is an optimisation process using a FORTRAN gradient algorithm. Springback of sheet parts during bending processes is simulated using finite element model (FEM) including damage evolution effects within the sheet. The numerical simulation of the damage evolution has been modelled by means of continuum damage approach. The Lemaitre damage model, taking into account the influence of triaxiality, has been implemented into ABAQUS/Standard code in order to predict the external fibres rupture evolution during the process and the material characteristics changes after bending. The simulation included die corner radius and punch-die clearance as the main variables.     

便携式多媒体SoC的视频处理方案

由于消费者对便携式多媒体设备的强劲需求及技术上的进步，设备制造商面对的挑战是必须把更多的功能和服务集成在越来越小型、价廉和功能多样化的产品中。要了解如何针对这个市场创建高价值及与众不同的多媒体SoC，我们必须先看看目前一般的便携式多媒体设备能够实现的技术范围。     

Fabrication of lotus-type porous carbon steel via continuous zone melting and its mechanical properties

Lotus-type porous carbon steel (lotus carbon steel) AISI1018 rods with long cylindrical pores aligned in one direction were fabricated using the continuous zone melting technique under nitrogen gas pressure of 2.5 MPa. The porosity decreased with increasing transference velocities of 40–160 μm s⁻¹. Tensile tests of the fabricated lotus-type carbon steel rods were performed. The elongation of lotus carbon steel increased after normalizing at 1200 K. The tensile strength and the Young's modulus decreased with increasing porosity. In contrast, the yield strength of lotus carbon steel did not decrease, even with a porosity of 20%, compared with that of non-porous carbon steel. This superior characteristic is attributed to solid-solution strengthening by solute nitrogen.     

Fault detection and identification with a new feature selection based on mutual information

This paper presents a fault diagnosis procedure based on discriminant analysis and mutual information. In order to obtain good classification performances, a selection of important features is done with a new developed algorithm based on the mutual information between variables. The application of the new fault diagnosis procedure on a benchmark problem, the Tennessee Eastman Process, shows better results than other well known published methods.     

Relationships Between Blanking Force and Part Geometry vs. Clearance, Tool Wear, and Sheet Thickness

The blanking of metal parts for electronic components is subjected to a variety of process parameters. In this paper, an experimental investigation into the blanking process was carried out using tools with four different wear states and four different clearances. The aim was to study the effects of the interaction between the clearance, the wear state of the tool, and the sheet metal thickness on the evolution of the blanking force and the geometry of the sheared profile.

Designed experiments are an efficient and cost-effective way to model and analyze the relationships that describe process variations.

The results of the proposed experimental investigation show the strong dependence between the geometrical quality of the blanked part and the magnitude of the force applied on the tool as well as the variations in the process factors.     

A Simple Approach for the Formation of Oxides,Sulfides, and Oxide–Sulfide Hybrid Nanostructures

The synthesis of various types of metal oxide and metal sulfide nanostructures through the thermal decomposition of single-source molecular precursors is presented. By varying the reaction conditions, such as solvent, precursor concentration, temperature, and time, we were able to control the shape of Fe₃O₄ (rectangles and belt-like structures), CoO nanofibers, and SnO₂ nanowires. Two sulfides are also presented: CdS filling a vertically aligned ZnO nanowire array (to create a hybrid structure) and SnS wires. The formation of various phases of iron oxide and cobalt oxide is also shown.     

Practical example of a coating process quality improvement through designed experiments

The objective of this paper is to show how coatings quality improvements may be achieved using experimental design. Designed experiments are an empirical approach to solving quality-related problems. We present a successfully designed experiment for improving the performance of a laminated fiber board coating process. The objective was to eliminate the aesthetic defects that sometimes appeared on the surface of decorative laminated fiber boards. Eleven parameters were tested for significance. A 32-run designed experiment was employed. Live tests were performed to identify the factor settings (the set points at which a factor is placed during the designed experiment) that allowed the elimination of nearly all visual defects.