Xiang-Fei Jia

University of Otago , Taieri, Otago Region, New Zealand

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Publications (11)

  • Jianping Jia · Xiumei Zuo · Xiang-Fei Jia · [...] · Xiaoguang Wu
    [Show abstract] [Hide abstract] ABSTRACT: The status of dementia diagnosis and treatment of neurology outpatients in general hospitals in China remains unclear. From neurology outpatients at 36 randomly selected hospitals, we first collected baseline data concerning the number of dementia doctors, memory clinics, and patients diagnosed with dementia. In stage 2, we intervened based on drawbacks discovered in stage 1, implementing a dementia initiative program. In stage 3, we reinvestigated the outpatients to determine the effects of intervention. After intervention, all 36 hospitals had established memory clinics (205 dementia doctors) compared with only 6 (47 dementia doctors) before intervention. The percentage of patients diagnosed with dementia significantly increased from 0.10% (536 dementia patients of 553,986 outpatients) in stage 1 to 0.41% (2482 dementia patients of 599,214 outpatients) in stage 3. Proper diagnosis and treatment are unavailable to many dementia patients because of a lack of dementia doctors and memory clinics in China. Copyright © 2015 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.
    Article · Aug 2015 · Alzheimer's & dementia: the journal of the Alzheimer's Association
  • Andrew Trotman · Xiang-Fei Jia · Matt Crane
    [Show abstract] [Hide abstract] ABSTRACT: Previous work has examined space saving and throughput increasing techniques for long postings lists in an inverted file search engine. In this contribution we show that highly sporadic terms (terms that occur in 1 or 2 documents) are a high proportion of the unique terms in the collection and that these terms are seen in queries. The previously known space saving method of storing their short postings lists in the vocabulary is compared to storing in the postings file. We quantify the saving as about 6.5%, with no loss in precision, and suggest the adoption of this technique.
    Conference Paper · Dec 2013
  • Fang Li · Xiang-Fei Jia · Jianping Jia
    [Show abstract] [Hide abstract] ABSTRACT: The Informant Questionnaire on Cognitive Decline in the Elderly individuals (IQCODE) is a reliable, validated informant-based instrument. Most of the studies well support the validity of the IQCODE in dementia screening, but the sensitivity of the rating scale at the early stage during the course of dementia is limited. In this study, we investigate the utility of the IQCODE for patients with mild cognitive impairment (MCI) and the discriminative power of the IQCODE in patients having MCI with and without functional impairment. The samples included mild Alzheimer disease (AD, N = 280), MCI ([N = 657], further divided into 2 subgroups: patients with MCI having functional impairment [MCI-fi, N = 357] and patients having MCI without functional impairment [MCI-fn, N = 300]), and normal cognition (NC, N = 274). The IQCODE, Mini-Mental State Examination (MMSE), and other neuropsychological tests were administered to all participants. Logistic regression and receiver-operating characteristic (ROC) curves were used to evaluate the diagnostic ability of the IQCODE, compared to the MMSE. The optimal cutoff scores of the IQCODE were 3.19 for the MCI (sensitivity/specificity: 0.979/0.714) and MCI-fn (0.900/0.817), 3.25 for the MCI-fi (0.978/0.701), and 3.31 for mild AD (0.893/0.779), while the MMSE was identical, that is 26, for both MCI and its functional normal and functional impaired subgroups (0.892/0.755, 0.867/0.745, and 0.913/0.745, respectively) and 24 for mild AD (0.807/0.836). The discriminating accuracy of the IQCODE was slightly superior to that of the MMSE but did not reach statistical significance. Our study suggests that the IQCODE might be useful in screening for MCI, with hierarchical scores indicating functional normal or impaired.
    Article · Nov 2012 · Journal of Geriatric Psychiatry and Neurology
  • Yi Xing · Wei Qin · Fang Li · [...] · Jianping Jia
    [Show abstract] [Hide abstract] ABSTRACT: Although numerous studies have been carried out to determine the effects of sex hormones on Alzheimer's disease (AD), little is known about the associations between sex hormones and VaD. The aim of this study was to compare serum sex hormone levels between VaD patients and normal controls, and to further determine the link between sex hormones and cognitive and neuropsychiatric manifestations of VaD. Serum levels of total estradiol (TE2), total testosterone (TT), luteinizing hormone (LH), and sex hormone binding globulin (SHBG) were measured in 87 VaD patients and 110 cognitive normal controls. The levels of bioavailable estradiol (BE2) and bioavailable testosterone (BT) were calculated. The VaD patients underwent the tests of global cognitive function, verbal memory, and visuospatial, and executive ability. The Neuropsychiatric Inventory (NPI) was used to assess neuropsychiatric symptoms. Compared to controls, the testosterone and SHBG levels were lower in male VaD patients, and the estradiol levels were higher in female VaD patients. The hormones levels were not correlated with cognitive functions among either male or female VaD patients. There were no associations between hormone levels and neuropsychiatric symptoms among male patients, while the TE2 and TT levels were positively associated with apathy and anxiety, respectively among female patients. Our findings suggested there were sex hormone level changes in VaD patients in comparison with cognitive normal controls. Sex hormones were associated with neuropsychiatric symptoms among female but not male VaD patients.
    Article · Oct 2012 · Archives of gerontology and geriatrics
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    [Show abstract] [Hide abstract] ABSTRACT: Studies on gender differences in the clinical manifestations of vascular dementia (VaD) are still lacking. In the present study, gender comparisons of cognitive and neuropsychiatric profiles were conducted separately for mild and moderate-to-severe VaD in a total of 467 patients with VaD. There were no significant gender differences in cognitive manifestations, except that females performed better on immediate verbal recall than males in mild stage. Women were more likely to exhibit delusions (15.5% vs 7.4%), hallucinations (9.5% vs 3.4%), and depression (43.1% vs 27.3%) in mild stage. The predominance of male patients was observed in apathy at moderate-to-severe stage (50.5% vs 34.8%). To conclude, gender differences existed in neuropsychiatric symptoms of VaD and were especially pronounced in mild stage. Delusions, hallucinations, and depression were more prevalent in females in mild VaD, with the male predominance only in apathy in the later stage.
    Full-text Article · Sep 2012 · American Journal of Alzheimer s Disease and Other Dementias
  • Yangtong Han · Jianping Jia · Xiang-Fei Jia · [...] · Suying Wang
    [Show abstract] [Hide abstract] ABSTRACT: Amyloid β and alpha 1-antichymotrypsin (ACT) play an important role in the pathogenesis of sporadic Alzheimer's disease (AD). The present study was to investigate whether a combination of plasma biomarkers and clinical data would discriminate AD from vascular dementia, other neurodegenerative dementia and non-demented controls. The study included 112 patients with AD, 85 patients with vascular dementia, 30 patients with other neurodegenerative dementia and 116 age-matched, non-demented controls. Although ACT, Aβ42 and the ratio of Aβ42/Aβ40 had significant differences between AD, vascular dementia, other neurodegenerative dementia and non-demented controls (P<0.001), none of them reached the sensitivity and specificity required for AD biomarkers. The combination of biomarkers and clinical data had higher discriminating power than either alone. Our results indicated that plasma biomarkers of ACT and the ratio of Aβ42/Aβ40 could discriminate AD from non-demented controls, vascular dementia, or other neurodegenerative dementias with higher diagnostic accuracy than clinical data and that if plasma biomarkers were combined with clinical data, the discriminating power was enhanced.
    Article · Apr 2012 · Neuroscience Letters
  • Yi Xing · Wei Qin · Fang Li · [...] · Jianping Jia
    [Show abstract] [Hide abstract] ABSTRACT: Studies on the associations between sex hormones and multiple neuropsychiatric symptoms of Alzheimer's disease (AD) are lacking. Apolipoprotein E (APOE) ε4 status may modify the effects of sex hormones on neuropsychiatric symptoms. A total of 86 male and 87 female AD patients participated in the present study. The adjusted associations between symptoms on the Neuropsychiatric Inventory and serum levels of estradiol (total, bioavailable) and testosterone (total, bioavailable) were analyzed. Agitation/aggression was negatively associated with quartiles of bioavailable estradiol among male patients, and positively associated with testosterone levels among female patients. The modifying effects of APOE genotype only existed in female patients. Those females with higher levels of estradiol and the ε4 allele had higher odds of agitation/aggression. Furthermore, the testosterone × APOE ε4 status interaction was positively associated with hallucinations in female patients. There were sex-specific effects of sex hormones on agitation/aggression in AD. Sex hormones and APOE ε4 status synergistically influence some neuropsychiatric symptoms among female but not male AD patients.
    Article · Mar 2012 · Dementia and Geriatric Cognitive Disorders
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    Jihui Lu · Dan Li · Fang Li · [...] · Jianping Jia
    [Show abstract] [Hide abstract] ABSTRACT: The Montreal Cognitive Assessment (MoCA) has been proved brief and sensitive to screen for mild cognitive impairment (MCI) and early dementia in some developed countries or areas. However, little MoCA data are available from mainland China. In this study, the MoCA was applied to 8411 Chinese community dwellers aged 65 or older (6283 = cognitively normal [CN], 1687 = MCI, and 441 = dementia). The MoCA norms were established considering significant influential factors. The optimal cutoff points were 13/14 for illiterate individuals, 19/20 for individuals with 1 to 6 years of education, and 24/25 for individuals with 7 or more years of education. With the optimal cutoffs, the sensitivity of the MoCA was 83.8% for all cognitive impairments, 80.5% for MCI and 96.9% for dementia, and the specificity for identifying CN was 82.5%. These indicate that with optimal cutoffs, the MoCA is valid to screen for cognitive impairment in elderly Chinese living in communities.
    Full-text Article · Dec 2011 · Journal of Geriatric Psychiatry and Neurology
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    Xiang-Fei Jia · David Alexander · Vaughn Wood · Andrew Trotman
    [Show abstract] [Hide abstract] ABSTRACT: In this paper, we describe University of Otago’s participation in Ad Hoc, Link-the-Wiki Tracks, Efficiency and Data Centric Tracks of INEX 2010. In the Link-the-Wiki Track, we show that the simpler relevance summation method works better for producing Best Entry Points (BEP). In the Ad Hoc Track, we discusses the effect of various stemming algorithms. In the Efficiency Track, we compare three query pruning algorithms and discusses other efficiency related issues. Finally in the Data Centric Track, we compare the BM25 and Divergence ranking functions.
    Full-text Chapter · Aug 2011
  • Xiang-Fei Jia
    [Show abstract] [Hide abstract] ABSTRACT: No one doubts that we have only scratched the surface of what is possible with the Web. The day is coming fast when the Web will become almost a virtual mind reader. Your intent, interests, and needs will be instantly perceived and the information you ...
    Conference Paper · Jan 2011
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    Andrew Trotman · Xiang-Fei Jia · Shlomo Geva
    [Show abstract] [Hide abstract] ABSTRACT: Building an efficient and an effective search engine is a very challenging task. In this paper, we present the efficiency and effectiveness of our search engine at the INEX 2009 Efficiency and Ad Hoc Tracks. We have developed a simple and effective pruning method for fast query evaluation, and used a two-step process for Ad Hoc retrieval. The overall results from both tracks show that our search engine performs very competitively in terms of both efficiency and effectiveness.
    Full-text Chapter · Jul 2010