Intrusion detection routers: Design, implementation and evaluation using an experimental testbed

In this paper, we present the design, the implementation details, and the evaluation results of an intrusion detection and defense system for distributed denial-of-service (DDoS) attack. The evaluation is conducted using an experimental testbed. The system, known as intrusion detection router (IDR), is deployed on network routers to perform online detection on any DDoS attack event, and then react with defense mechanisms to mitigate the attack. The testbed is built up by a cluster of sufficient number of Linux machines to mimic a portion of the Internet. Using the testbed, we conduct real experiments to evaluate the IDR system and demonstrate that IDR is effective in protecting the network from various DDoS attacks. © 2006 IEEE.published_or_final_versio

Novel organic-inorganic hybrid nanoparticles as non-viral gene vector

Novel hybrid biomaterial of gelatin-siloxane nanoparticles (GS NPs), with positive surface potential and lower cytotoxicity, was synthesized through a 2-step sol-gel process. The pDNA-GS NPs complex was formulated with high encapsulation efficiency, and exhibited and efficient transfection in vitro. We thus envision that the GS NPs material could serve as non-viral gene vectors for gene therapy

Near-IR sensitive Au-Au2S nanoparticles with biocompatibility for drug delivery

The near-infrared (NIR) sensitive Au-Au2S nanoparticles (NPs) have shown many advantages as potential drug delivery systems. To further investigate biological safety of Au-Au2S NPs, cytotoxicity was estimated by calcein AM/EthD-1 fluorescence staining and the lactate dehydrogenase (LDH) release. The effects of NPs on apoptosis of CHL cells were determined by flow cytometry with Annexin V-FITC/PI double staining. It is evident that the Au-Au2S NPs are non-cytotoxic below IC50 dosage

Corrective feedback for depth perception in CAVE-like systems

The perceived distance estimation in an immersive virtual reality system is generally underestimated to the actual distance. Approaches had been found to provide users with better dimensional perception. One method used in head-mounted displays is to interact by walking with visual feedback, but it is not suitable for a CAVE-like system, like imseCAVE, with confined spaces for walking. A verbal corrective feedback mechanism is proposed. The result shows that estimation accuracy generally improves after eight feedback trials although some estimations become overestimated. One possible explanation is the need of more verbal feedback trials. Further research on top-down approach for improvement in depth perception is suggested

Depth perception in virtual environment: the effects of immersive sytem and freedom of movement

8th International Conference on Virtual, Augmented and Mixed Reality in 18th International Conference on Human-Computer Interaction (HCI International 2016), Toronto, Canada, 17-22 July 2016Concerns over the use of virtual reality (VR) systems in experimental psychological research exist. It is found that human egocentric depth perception in a virtual environment (VE) has significant errors compared to real physical environment. It is hypothesized that due to the presence of a human body as a size reference in a mixed reality CAVE-like system, the accuracy of depth estimation will improve. The second hypothesis proposes that when a participant is allowed to move around the VE, motion parallax will supplement the depth perception ability. Results showed that the features of an immersive system did not aid the estimation. Around 40 % underestimation of actual distance was observed above 15 m. By using a 3D-military jet instead of 2D-wall as the judgment object, a significant improvement in the accuracy is found. Pictorial cues were hence, suggested as the improvement basis for next part of the study

Polymer-based nano/composites : theory, synthesis, modifications, and properties

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Chylothorax in Children After Congenital Heart Surgery

Background: A definitive management strategy for postoperative chylothorax remains elusive. We reviewed our experience in the management of chylothorax in children after congenital heart surgery. Methods: The case records of 51 patients, with a median age of 11 months (range, 4 days to 19.6 years), diagnosed to have postoperative chylothorax between 1981 and 2004 were reviewed. The responses of patients to nutritional modifications, octreotide therapy, and surgical interventions were noted. Results: The prevalence of postoperative chylothorax, which developed at a median of 9 days after operation (range, 0 to 24 days), was 0.85% (51 of 5,995). Four patients died, and among the 47 survivors the median duration and total volume of chylous drainage was 15 days (range, 1 to 89 days) and 156 mL/kg (range, 3 to 6,476), respectively. The duration of chyle output was significantly longer after the Fontan-type procedures (p = 0.0006). Twenty-one patients were diagnosed between 1981 and 1999 and managed by nutritional modifications, 2 of whom required further surgical interventions. Of the 30 patients diagnosed between 2000 and 2004, 12 responded to nutritional modifications alone while 18 were started on octreotide therapy at a median of 19.5 days (range, 7 to 35 days) after the onset of chylothorax. Fifteen of the 18 (83%) patients responded to octreotide therapy at 15.3 ± 5.5 days after starting octreotide, while 3 required further surgical interventions. None developed side effects from octreotide therapy. Conclusions: Octreotide has been incorporated into the management algorithm of postoperative chylothorax and appears to be a useful adjunctive therapy. © 2006 The Society of Thoracic Surgeons.link_to_subscribed_fulltex

22q11.2 deletion syndrome in adult Chinese Patients with Conotruncal Anomalies: dysmorphisms, clinical features and underdiagnosis

Poster Presentation (Doctor’s Session)22q11.2 deletion syndrome (22q11.2DS) is a multi-systemic disorder with high phenotypic variability. Underdiagnosis in adults is common and recognition of facial dysmorphic features can be affected by patient age and ethnicity. This study aims to determine the prevalence of undiagnosed 22q11.2DS in adult Chinese patients with conotruncal anomalies and to delineate their facial dysmorphic features and extra-cardiac manifestations. We recruited consecutively 156 patients with conotruncal anomalies in an adult congenital heart disease (CHD) clinic in Hong Kong and screened for 22q11.2DS using fluorescence- PCR and fluorescence in-situ hybridisation. Assessment for dysmorphic features was performed by a cardiologist at initial screening and then by a clinical geneticist upon result disclosure. Clinical photographs were taken with consent and childhood photographs were collected. Eighteen patients (11.5%) were diagnosed with 22q11.2DS, translating into 1 previously unrecognised diagnosis of 22q11.2DS in every 10 adult patients with conotruncal anomalies. While dysmorphic features were detected by our clinical geneticist in all patients, only two-thirds were considered dysmorphic by our cardiologist upon first assessment. Evolution of facial dysmorphic features was noted with age. Extra-cardiac manifestations included velopharyngeal incompetence or cleft palate (44%), hypocalcaemia (39%), neurodevelopmental anomalies (33%), thrombocytopenia (28%), psychiatric disorders (17%), epilepsy (17%) and hearing loss (17%). We conclude that under-diagnosis of 22q11.2DS in Chinese adults with conotruncal defects is common and facial dysmorphic features may not be reliably recognised in the setting of adult CHD clinic. In order to avoid missing the diagnosis, molecular testing of 22q11.2DS should be offered to patients with conotruncal defects regardless of the facial features