Time-Scale Domain Characterization of Time-Varying Ultrawideband Infostation Channel

The time-scale domain geometrical-based method for the characterization of the time varying ultrawideband (UWB) channel typical of an infostation channel is presented. Compared to methods that use Doppler shift as a measure of time-variation in the channel this model provides a more reliable measure of frequency dispersion caused by terminal mobility in the UWB infostation channel. Particularly, it offers carrier frequency independent method of computing wideband channel responses and parameters which are important for ultrawideband systems. Results show that the frequency dispersion of the channel depends on the frequency and not on the choice of bandwidth. And time dispersion depends on bandwidth and not on the frequency. It is also shown that for time-varying UWB, frame length defined over the coherence time obtained with reference to the carrier frequency results in an error margin which can be reduced by using the coherence time defined with respect to the maximum frequency in a given frequency band. And the estimation of the frequency offset using the time-scale domain (wideband) model presented here (especially in the case of multiband UWB frequency synchronization) is more accurate than using frequency offset estimate obtained from narrowband models

Isolation and characterization of malaria PfHRP2 specific V-NAR antibody fragments from immunized shark phage display library

Background Malaria rapid diagnostic tests (RDTs) represent an important antibody based immunoassay platform. Unfortunately, conventional monoclonal antibodies are subject to degradation shortening shelf lives of RDTs. The variable region of the receptor (VNAR) from shark has a potential as alternative to monoclonal antibodies in RDTs due to high thermal stability. Methods In this study, new binders derived from shark VNAR domains library were investigated. Following immunization of a wobbegong shark (Orectolobus ornatus) with three recombinant malaria biomarker proteins (PfHRP2, PfpLDH and Pvaldolase), a single domain antibody (sdAb) library was constructed from splenocytes. Target-specific VNAR phage were isolated by panning. One specific clone was selected for expression in Escherichia coli expression system, and study of binding reactivity undertaken. Results The primary VNAR domain library possessed a titre of 1.16 × 106&nbsp;pfu/mL. DNA sequence analysis showed 82.5% of isolated fragments appearing to contain an in-frame sequence. After multiple rounds of biopanning, a highly dominant clone specific to PfHRP2 was identified and selected for protein production in an E. coli expression system. Biological characterization showed the recombinant protein expressed in periplasmic has better detection sensitivity than that of cytoplasmic proteins. Assays of binding activity indicated that its reactivity was inferior to the positive control mAb C1–13. Conclusions Target-specific bacteriophage VNARs were successfully isolated after a series of immunization, demonstrating that phage display technology is a useful tool for selection of antigen binders. Generation of new binding reagents such as VNAR antibodies that specifically recognize the malaria biomarkers represents an appealing approach to improve the performance of RDTs.</p

The Effect of Organisational Climate on Employees’ Creative Performance through Knowledge Sharing Behaviour

Malaysia has achieved significant industrial growth over the years due to the enterprising intervention of multinational companies (MNCs). The organisational climate in terms of its collaborative nature and innovative efforts has led to the enhancement of creativity among MNCs. The extent of knowledge sharing behaviour within MNCs, particularly in the Malaysian context, has not been thoroughly researched. A huge primary survey involving 20 MNCs with 155 respondents from both manufacturing and service sectors was included in this study. The findings of the study reveal that knowledge donating and knowledge collecting highly and positively influence creative performance. Interestingly, knowledge collecting mediates the relationship between an innovative climate and creative performance while a collaborative climate was found to highly and positively influence MNCs’ creative performance through knowledge donating. Thus, knowledge sharing behaviour is pivotal for the success of MNCs in terms of generating new ideas, promoting best practices, continuously improving and reducing the redundancy cost of learning to facilitate organisational effectiveness

A performance evaluation of pruning effects on hybrid neural network

In this paper, we explore the pruning effects on a hybrid mode sequential learning algorithmnamely FuzzyARTMAP-prunable Radial Basis Function (FAM-PRBF) that utilizes FuzzyARTMAP to learn a training dataset and Radial Basis Function Network (RBFN) to performregression and classification. The pruning algorithm is used to optimize the hidden layer ofthe RBFN. The experimental results show that FAM-PRBF has successfully reduced thecomplexity and computation time of the neural network.Keywords: pruning; radial basis function network; fuzzy ARTMAP

Evacuation of the Pleural Cavity With an Infant Feeding Catheter Following en Bloc Resection of Hepatocellular Carcinoma and Involved Diaphragm–an Institutional Experience

En bloc resection of hepatocellular carcinoma and the involved diaphragm will, towards the end of operation, require evacuation of the pleural cavity, usually with a chest drain. We describe our method and experience of evacuating the pleural cavity, at the time of diaphragmatic repair, with an infant feeding catheter without the need of a chest drain. We have found the method safe and efficacious

High frame rate contrast enhanced ultrasound imaging for slow flow: influence of ultrasound pressure and flow rate on bubble disruption and image persistence

Contrast-enhanced ultrasound (CEUS) utilising microbubbles shows great potential for visualising lymphatic vessels and identifying sentinel lymph nodes (SLNs) which are valuable for axillary staging in breast cancer patients. However, current CEUS imaging techniques have limitations that affect the accurate visualisation and tracking of lymphatic vessels and SLN. (i) Tissue artefacts and bubble disruption can reduce the image contrast. (ii) Limited spatial and temporal resolution diminishes the amount of information that can be captured by CEUS. (iii) The slow lymph flow makes Doppler-based approaches less effective. This work evaluates on a lymphatic vessel phantom the use of high frame rate (HFR) CEUS for the detection of lymphatic vessels where flow is slow. Specifically, the work particularly investigates the impact of key factors in lymphatic imaging, including ultrasound pressure and flow velocity as well as probe motion during vessel tracking, on bubble disruption and image contrast. Experiments were also conducted to apply HFR CEUS imaging on vasculature in a rabbit popliteal lymph node (LN). Our results show that (i) HFR imaging and singular value decomposition (SVD) filtering can significantly reduce tissue artefacts in the phantom at high clinical frequencies; (ii) the slow flow rate within the phantom makes image contrast and signal persistence more susceptible to changes in ultrasound amplitude or mechanical index (MI), and an MI value can be chosen to reach a compromise between images contrast and bubble disruption under slow flow condition; (iii) probe motion significantly decreases image contrast of the vessel, which can be improved by applying motion correction before SVD filtering; (iv) the optical observation of the impact of ultrasound pressure on HFR CEUS further confirms the importance of optimising ultrasound amplitude and (v) vessels inside rabbit LN with blood flow less than 3 mm/s are clearly visualised

Charging management protocol for near field communication charging

The current multiplicity of mobile communication devices has provided an impetus for the research into new mechanisms to supplement battery charge. Wireless charging is a solution that serves to eliminate the cable requirements of typical battery charging implementations. Numerous wireless charging implementations are based on inductive coupling, similar to existing non-radiative short range communication systems. This study proposes incorporating a charge management protocol into the existing Near Field Communication Interface and Protocol-1 (NFCIP-1) specification to achieve NFC-enabled wireless charging. To this end, the original NFCIP-1 protocol has been modified through a time-sharing arrangement to support a charging task within the protocol cycle. Simulations of the modified protocol cycle were implemented using an appropriate battery model and charging algorithm. Numerical results show that the modified protocol is able to charge the target battery with minimum communication overhead. Satisfactory performance is also observed for charging up to 2 target devices in a single session