Heterotrophic growth and nutritional aspects of the diatom Cyclotella cryptica (Bacillariophyceae): Effect of some environmental factors

To investigate the nutritional value of the diatom Cyclotella cryptica (Reimann, Lewin, and Guillard) as an alternative feed for use in the aquaculture industry, the heterotrophic growth characteristics and resultant fatty acid profile of the microalga were studied when cultivated under a variety of controlled salinity and temperature conditions. In addition, the effects of pH on the growth characteristics were also studied. The maximum specific growth rate was affected by initial pH and cultivation temperature, but not by salinity. The optimal pH and temperature ranges for growth were 7.2 to 8.1 and 22.5 to 25.0 °C, respectively. Lipid accumulation and the fatty acid composition were also affected by cultivation temperature and salinity. The optimal temperature range and salinity level for lipid accumulation were 18.0 to 25.0 °C and 11.2 psu, respectively. In all cases the fatty acid distribution was similar, with the most abundant fatty acids being palmitic acid (16:0), palmitoleic acid (16:1 n-7), stearidonic acid (18:4 n-3, SDA), eicosapentaenoic acid (20:5 n-3, EPA), and decosahexaenoic acid (22:6 n-3, DHA).     

Multimerization behaviour of single chain Fv variants for the tumour-binding antibody B72.3

A systematic study has been performed on the relationship betweenlinker length, relative orientation of variable domains, multimerizationbehaviour and antigen binding activity for single chain Fvs(scFvs) of the tumour-binding antibody B72.3. Thirteen scFvvariants with linkers comprising up to six repeats of the motifGly-Gly-Gry-Gly-Ser were studied. All these scFvs showed a tendencyto form dimers or higher molecular weight species, and thistendency decreased with increasing linker length. The dimersand higher molecular weight forms may arise from head to tailintermolecular association of V_H and V_L domains. For each linkerlength, scFvs with the organization VL-linker-VH showed greaterbinding activity than those with the organization VH-linker-VL.In fact, for the latter organization only the variant with a30 amino acid linker showed good binding activity, suggestingthat (0 for B72.3 the C-tenninus of VH or the N-tenninus ofVL makes a structural contribution to antigen binding, and (ii)shorter linkers interfere with this contribution. Antigen bindingstudies on scFvs should be interpreted with caution becauseof their tendency to multlmerize. Such multimerization can beminimized by using linkers longer than those in common use     

Influence of A-site Ba substitution on microwave dielectric properties of (BaxMg1−x)(A0.05Ti0.95)O3 (A=Zr,Sn) ceramics

The microwave dielectric properties of (Ba_xMg_1−x)(A_0.05Ti_0.95)TiO₃ (A=Zr, Sn) ceramics were investigated with regard to substitution of Ba for Mg of A-site. The microwave dielectric properties were correlated with the Ba content. With an increase in Ba content from 0.01 to 0.1, the dielectric constant and the τ_f value increased, but the Q×f value decreased. The sintered (Ba_xMg_1−x)(Zr_0.05Ti_0.95)TiO₃ (called B_xMZT) ceramics had a permittivity in the range of 19.1−20.6, quality factor from 180,000 to 25,000 GHz, and variation in temperature coefficient of resonant frequency from −35 to −39 ppm/°C with increasing composition x. For sintered (Ba_xMg_1−x)(Sn_0.05Ti_0.95)TiO₃ (called B_xMST) ceramics, the dielectric constant increased from 19 to 20.5, Q×f value increased from 120,000 to 37,000 (GHz), and the τ_f value increased from −50 to −3.3 ppm/°C as the x increased from 0.01 to 0.1. When A=Sn and x=0.1, (Ba_0.1Mg_0.9)(Sn_0.05Ti_0.95)TiO₃ ceramics exhibited dielectric constant of 20.5, Q×f value of 37,000 (GHz), and a near-zero τ_f value of −3.3 ppm/°C sintered at 1210 °C for 4 h.     

Two‐dimensional electrolyte nature of exfoliated montmorillonite nanoplatelets fabricated by soap‐free emulsion polymerization and their affinity for cations

Montmorillonite (MMT) nanoplatelets, fabricated by the exfoliation of MMT during participating in the soap‐free emulsion polymerization of methyl methacrylate, were well‐dispersed in water and performed like a two‐dimensional electrolyte. Their ionic conductivity roughly follows the Manning's limiting law for the conduction of a polyelectrolyte. The dissociated MMT nanoplatelets that carry negative charges in water were able to rapidly adsorb cations, such as tris(2,2′‐bipyridyl)ruthenium(II) (Ru(bpy)) and methylene blue (MB⁺), and recover into a smectic configuration floating as a separating phase. By using the Langmuir equation, we were able to estimate the occupied surface areas of MMT nanoplatelets by each Ru(bpy) and MB⁺ cations as 4.708 and 1.806 nm²/ion, respectively. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Emergence of Ag particles and their effects on the mechanical properties of TaN-Ag nanocomposite thin films

TaN-Ag nanocomposite films were deposited by reactive co-sputtering on tool steel substrates. The films were then annealed using RTA (Rapid Thermal Annealing) at 350 °C for 2, 4, 8 min respectively to induce the nucleation and growth of Ag particles in TaN matrix and on film surface. C-AFM (Conductive Atomic force Microscopy) and FESEM (Field-Emission Scanning Electron Microscopy) were applied to examine the Ag nano-particles emerged on the surface of these thin films. A nano-indenter and a pin-on-disk tribometer were used to study the effect of annealing on the films' mechanical properties. The results reveal that annealing by RTA can cause Ag nano-particles to emerge on the TaN surface. Consequently, the mechanical properties of the films will vary depending on annealing conditions, Ag content, and Ag particle emergence.     

Integrated real-time roof monitoring

CSIRO has recently developed a real-time roof monitoring system for underground coal mines and successfully tried the system in gate roads at Ulan Mine. The system integrated displacement monitoring, stress monitoring and seismic monitoring in one package. It included GEL multianchor extensometers, vibrating wire uniaxial stress meters, ESG seismic monitoring system with microseismic sensors and high-frequency AE sensors. The monitoring system automated and the data can be automatically collected by a central computer located in an underground nonhazardous area. The data are then transferred to the surface via an optical fiber cable. The real-time data were accessed at any location with an Internet connection. The trials of the system in two tailgates at Ulan Mine demonstrate that the system is effective for monitoring the behavior and stability of roadways during longwall mining. The continuous roof displacement/stress data show clear precursors of roof falls. The seismic data (event count and locations) provide insights into the roof failure process during roof fall.     

Modelling complex manufacturing systems using discrete event simulation

This paper presents an approach in simulating complex manufacturing systems. The approach is founded on developing several general purpose simulation generators for an assembly station, a manufacturing cell, and an inventory transfer function. These simulation generators can then be linked together to create a model of a complex manufacturing system. A typical manufacturing system is modelled using these simulation generators and the results summarized.     

Guided Neural Network Learning Using a Fuzzy Controller,with Applications to Textile Spinning

We apply neural networks to build a metamodel of the relation between key input parameters and output performance measures of a simulated textile spinning plant. We investigate two different neural network estimation algorithms, namely back-propagation and an algorithm incorporating a fuzzy controller for the learning rate. According to our experience, both algorithms are capable of providing high-quality predictions. In addition, results obtained using a fuzzy controller for the learning rate suggest a significant potential for speeding up the training process.     

The comparison of electroencephalograms recorded before and after electrical stunning of cattle

Electroencephalograms (EEGs) were recorded before and after ‘head-only’ electrical stunning of adult cattle. Epochs of 8·5 s duration derived from the pre-and the post-stun EEG signals were compared for differences in scale and frequency.

The frequency structures of two selected epochs from the one animal were evaluated using the periodogram ordinates derived by calculating the Fast Fourier Transform. The comparison of the two pre-stun epochs indicated that, within the one animal, the pre-stun EEG signal had a consistent frequency pattern. Similarly, a comparison of two post-stun epochs indicated that the post-stun EEG signal also had a consistent frequency pattern. The comparison of pre- and post-stun epochs indicated a consistent increases in amplitude after stunning. Additionally, after stunning, there was an increase in the power of frequencies in the range 4–8 Hz and a decrease in the power of certain frequencies in the range 15–25 Hz. Although there was considerable animal-to-animal variation it was demonstrated that electric stunning produced definable changes in the EEG signal.