300 research outputs found

    Adding learning to cellular genetic algorithms for training recurrent neural networks

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    A study of the Lamarckian evolution of recurrent neural networks

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    Anatomic variations of neurovascular structures of the ankle in relation to arthroscopic portals: a cadaveric study of Chinese subjects.

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    PURPOSE: To investigate anatomic variations of neurovascular structures in the ankle and the safety margin for arthroscopic portals. METHODS: 11 left and 12 right ankles from 8 female and 15 male fresh cadavers of Chinese ethnicity aged 53 to 88 (mean, 68) years were used. The ankle was standardised in a plantigrade position, zero-degree inversion, and neutral rotation. Four ankle portals, namely anteromedial (AM), anterolateral (AL), posteromedial (PM) and posterolateral (PL), were identified using 23-gauge needles. Skin and subcutaneous fat were dissected from the underlying fascia to visualise neurovascular structures. Distances were measured from: (1) the AM portal to the saphenous vein and nerve and its branches, (2) the AL portal to branches of the superficial peroneal nerves, of which the lateral one was labelled as the intermediate dorsal cutaneous branch and the medial one as the medial dorsal cutaneous branch, (3) the PM portal to the posterior tibial neurovascular bundles, and (4) the PL portal to the sural nerve. RESULTS: The distances from (1) the AM portal to branches of the great saphenous vein and nerve, and (2) the AL portal to the intermediate dorsal cutaneous branch of the superficial peroneal nerve were short and may be an anatomic hazard. Variations were significant among the cadavers in terms of distances of the portals to the neurovascular structures. CONCLUSION: In Chinese cadavers, variations of neurovascular structures are significant. Care must be taken to avoid inadvertent injury during ankle arthroscopy.published_or_final_versio

    Optical properties of ferroelectric nanocrystal-containing polymer BaTiO₃/polycarbonate films

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    Author name used in this publication: C. L. MakAuthor name used in this publication: K. H. Wong2005-2006 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    An exploratory study on the social and genotypic clustering of HIV infection in men having sex with men

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    OBJECTIVE: To explore the clustering of HIV infected men having sex with men (MSM) using social network approach in conjunction with the phylogenetic relationship of the virus strains. DESIGN: An exploratory study incorporating social network and phylogenetic analysis. METHODS: Recently diagnosed HIV-infected MSM attending one major HIV specialist clinic in Hong Kong were recruited in the study involving the administration of a self-administered questionnaire on behaviours and partnership patterns using a Likert Scale, the results of which were assessed using social network analysis and in context of the phylogenetic analysis from sequencing the HIV-1 pol gene, as part of the clinical investigation for genotypic resistance. Clusters were defined using social and molecular methods. RESULTS: An 'Internet-centred' cluster and 'Sauna-centred' cluster could be delineated using correspondence analysis and network diagrams. The main distinguishing features of MSM in the 'Internet-centred' social cluster were: younger age, higher education level, and multiple partner types. Three genetic clusters could be identified in the phylogenetic tree, two of which associated with Internet use and one with sauna for sex partnership. There were partial overlaps between social and genetic clusters. Characteristically, the virus strains in sauna users were more disperse compared with the closely knit configuration of those using Internet. CONCLUSION: The principle of the duality of place and person can be strategically applied in epidemiologic investigation. The characterization of MSM cluster using anonymized network data provides a potentially powerful tool for informing public health intervention. © 2009 Lippincott Williams & Wilkins, Inc.postprin

    DJ-1 interacts with and regulates paraoxonase-2, an enzyme critical for neuronal survival in response to oxidative stress.

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    Loss-of-function mutations in DJ-1 (PARK7) gene account for about 1% of all familial Parkinson's disease (PD). While its physiological function(s) are not completely clear, DJ-1 protects neurons against oxidative stress in both in vitro and in vivo models of PD. The molecular mechanism(s) through which DJ-1 alleviates oxidative stress-mediated damage remains elusive. In this study, we identified Paraoxonase-2 (PON2) as an interacting target of DJ-1. PON2 activity is elevated in response to oxidative stress and DJ-1 is crucial for this response. Importantly, we showed that PON2 deficiency hypersensitizes neurons to oxidative stress induced by MPP+ (1-methyl-4-phenylpyridinium). Conversely, over-expression of PON2 protects neurons in this death paradigm. Interestingly, PON2 effectively rescues DJ-1 deficiency-mediated hypersensitivity to oxidative stress. Taken together, our data suggest a model by which DJ-1 exerts its antioxidant activities, at least partly through regulation of PON2

    Kawasaki disease in Hong Kong, 1994 to 2000

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    OBJECTIVE. To describe the epidemiology, clinical characteristics, and management of Kawasaki disease in children in Hong Kong. DESIGN. Retrospective survey of medical records from July 1994 to June 1997, and prospective data collection from July 1997 to June 2000. SETTING. Hospitals with a paediatric unit in Hong Kong. PATIENTS. Patients diagnosed with Kawasaki disease between July 1994 and June 2000 in public hospitals in Hong Kong. MAIN OUTCOME MEASURES. Incidence of Kawasaki disease and coronary artery aneurysm rates. RESULTS. A total of 696 cases of Kawasaki disease were reported. There were 435 (62.5%) boys and 261 (37.5%) girls giving a male to female ratio of 1.7:1. The age ranged from 1 month to 15 years 5 months with a median of 1.7 years. Infants (<1 year) constituted the largest group of patients (223,32.0%) and overall, 638 (91.7%) were younger than 5 years. Skin rash, conjunctivitis, and oral signs were among the principal clinical features present in over 80% of cases. Prominent cervical lymph nodes larger than 1.5 cm were less commonly found (24%). Coronary artery aneurysms or ectasia were present in 15.7% (109/696), 8.5% (59/696), and 5.0% (35/696) of patients at 2, 4, and 8 weeks, respectively. The incidence of Kawasaki disease per 100 000 children under 5 years was significantly higher in the prospective study period than in the retrospective period (39 vs 26, <0.001). CONCLUSION. The incidence of Kawasaki disease is high in Hong Kong and is 39 per 100 000 children below 5 years of age. The coronary artery aneurysm prevalence is 5%. Intravenous gamma-globulin and high-dose aspirin is the mainstay of treatment.published_or_final_versio

    Assessment of fall-related self-efficacy and activity avoidance in people with Parkinson's disease

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    <p>Abstract</p> <p>Background</p> <p>Fear of falling (FOF) is common in Parkinson's disease (PD), and it is considered a vital aspect of comprehensive balance assessment in PD. FOF can be conceptualized differently. The Falls-Efficacy Scale (FES) assesses fall-related self-efficacy, whereas the Survey of Activities and Fear of Falling in the Elderly (SAFFE) assesses activity avoidance due to the risk of falling. This study aimed at investigating the validity and reliability of FES and SAFFE in people with PD.</p> <p>Methods</p> <p>Seventy-nine people with PD (mean age; 64 years, SD 7.2) completed the Swedish version of FES(S), SAFFE and the physical functioning (PF) scale of the 36-Item Short-Form Health Survey (SF-36). FES(S) and SAFFE were administered twice, with an 8.8 (SD 2.3) days interval. Assumptions for summing item scores into total scores were examined and score reliability (Cronbach's alpha and test-retest reliability) were calculated. Construct validity was assessed by examining the pattern of Spearman correlations (r<sub>s</sub>) between the FES(S)/SAFFE and other variables, and by examining differences in FES(S)/SAFFE scores between fallers and non-fallers, genders, and between those reporting FOF and unsteadiness while turning.</p> <p>Results</p> <p>For both scales, item mean scores (and standard deviations) were roughly similar and corrected item-total correlations exceeded 0.4. Reliabilities were ≥0.87. FES(S)-scores correlated strongest (r<sub>s</sub>, -0.74, p < 0.001) with SAFFE-scores, whereas SAFFE-scores correlated strongest with PF-scores (r<sub>s</sub>, -0.76, p < 0.001). Both scales correlated weakest with age (r<sub>s </sub>≤ 0.08). Experiencing falls, unsteadiness while turning, and FOF was associated with lower fall-related self-efficacy and higher activity avoidance.</p> <p>Conclusions</p> <p>This study provides initial support for the score reliability and validity of the FES(S) and SAFFE in people with PD.</p
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