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Rajagopalan V, Allexandre D, Yue GH, Pioro EP. Diffusion Tensor Imaging Evaluation of Corticospinal Tract Hyperintensity in Upper Motor Neuron-Predominant ALS Patients. J Aging Res 2011; 2011:481745. [PMID: 22132329 PMCID: PMC3205652 DOI: 10.4061/2011/481745] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Accepted: 08/09/2011] [Indexed: 12/03/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) patients with predominant upper motor neuron (UMN) signs occasionally have hyperintensity of corticospinal tract (CST) on T2- and proton-density-(PD-) weighted brain images. Diffusion tensor imaging (DTI) was used to assess whether diffusion parameters along intracranial CST differ in presence or absence of hyperintensity and correspond to UMN dysfunction.
DTI brain scans were acquired in 47 UMN-predominant ALS patients with (n = 21) or without (n = 26) CST hyperintensity and in 10 control subjects. Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were measured in four regions of interests (ROIs) along CST. Abnormalities (P < 0.05) were observed in FA, AD, or RD in CST primarily at internal capsule (IC) level in ALS patients, especially those with CST hyperintensity. Clinical measures corresponded well with DTI changes at IC level. The IC abnormalities suggest a prominent axonopathy in UMN-predominant ALS and that tissue changes underlying CST hyperintensity have specific DTI changes, suggestive of unique axonal pathology.
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Kisiel-Sajewicz K, Fang Y, Hrovat K, Yue GH, Siemionow V, Sun CK, Jaskólska A, Jaskólski A, Sahgal V, Daly JJ. Weakening of synergist muscle coupling during reaching movement in stroke patients. Neurorehabil Neural Repair 2011; 25:359-68. [PMID: 21343527 DOI: 10.1177/1545968310388665] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND After hemiparetic stroke, coordination of the shoulder flexor and elbow extensor muscles during a reaching movement is impaired and contributes to poor performance. OBJECTIVE The aim was to determine whether functional coupling between electromyographic signals of synergist muscles during reaching was weakened in stroke patients who had poor motor coordination. METHODS Surface electromyography (EMG) from the anterior deltoid, triceps brachii, biceps brachii, pectoralis major, supraspinatus, and latissimus dorsi of the affected upper limb in 11 stroke patients (mean Fugl-Meyer upper extremity score 27 ± 8) and in the dominant arm of 8 healthy controls were measured. RESULTS Coherence between the EMG of the anterior deltoid and triceps brachii, 2 synergists for reaching, was lower in patients compared with controls, in the 0- to 11-Hz range. Detailed segmented frequency-range analysis indicated significant differences in the coherence between groups in 0- to 3.9-Hz and 4- to 7.9-Hz ranges. CONCLUSIONS This weakened functional coupling may contribute to poor reaching performance and could be a consequence of a loss of common drive at the frequency bands as a result of interruption of information flow in the corticospinal pathway.
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Wang CM, Lo LC, Zhu ZY, Pang HY, Liu HM, Tan J, Lim HS, Chou R, Orban L, Yue GH. Mapping QTL for an adaptive trait: the length of caudal fin in Lates calcarifer. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2011; 13:74-82. [PMID: 20352272 DOI: 10.1007/s10126-010-9271-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2009] [Accepted: 12/17/2009] [Indexed: 05/29/2023]
Abstract
The caudal fin represents a fundamental design feature of fishes and plays an important role in locomotor dynamics in fishes. The shape of caudal is an important parameter in traditional systematics. However, little is known about genes involved in the development of different forms of caudal fins. This study was conducted to identify and map quantitative trait loci (QTL) affecting the length of caudal fin and the ratio between tail length and standard body length in Asian seabass (Lates calcarifer). One F1 family containing 380 offspring was generated by crossing two unrelated individuals. One hundred and seventeen microsatellites almost evenly distributed along the whole genome were genotyped. Length of caudal fin at 90 days post-hatch was measured. QTL analysis detected six significant (genome-wide significant) and two suggestive (linkage-group-wide significant) QTL on seven linkage groups. The six significant QTL explained 5.5-16.6% of the phenotypic variance, suggesting these traits were controlled by multiple genes. Comparative genomics analysis identified several potential candidate genes for the length of caudal fin. The QTL for the length of caudal fin detected for the first time in marine fish may provide a starting point for the future identification of genes involved in the development of different forms of caudal fins in fishes.
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Yang Q, Siemionow V, Yao W, Sahgal V, Yue GH. Single-Trial EEG-EMG Coherence Analysis Reveals Muscle Fatigue-Related Progressive Alterations in Corticomuscular Coupling. IEEE Trans Neural Syst Rehabil Eng 2010; 18:97-106. [DOI: 10.1109/tnsre.2010.2047173] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Li ZQ, Li JL, Feng XY, Xie N, Feng JB, Yue GH. Sixteen polymorphic microsatellites for breeding of Chinese soft-shelled turtles (Pelodiscus sinensis). Anim Genet 2010; 41:446-7. [PMID: 20331610 DOI: 10.1111/j.1365-2052.2010.02029.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Marusiak J, Jaskólska A, Kisiel-Sajewicz K, Yue GH, Jaskólski A. EMG and MMG activities of agonist and antagonist muscles in Parkinson’s disease patients during absolute submaximal load holding. J Electromyogr Kinesiol 2009; 19:903-14. [DOI: 10.1016/j.jelekin.2008.03.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2007] [Revised: 03/03/2008] [Accepted: 03/11/2008] [Indexed: 10/22/2022] Open
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Yavuzsen T, Davis MP, Ranganathan VK, Walsh D, Siemionow V, Kirkova J, Khoshknabi D, Lagman R, LeGrand S, Yue GH. Cancer-related fatigue: central or peripheral? J Pain Symptom Manage 2009; 38:587-96. [PMID: 19515528 DOI: 10.1016/j.jpainsymman.2008.12.003] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2008] [Revised: 12/03/2008] [Accepted: 01/02/2009] [Indexed: 11/17/2022]
Abstract
To evaluate cancer-related fatigue (CRF) by objective measurements to determine if CRF is a more centrally or peripherally mediated disorder, cancer patients and matched noncancer controls completed a Brief Fatigue Inventory (BFI) and underwent neuromuscular testing. Cancer patients had fatigue measured by the BFI, were off chemotherapy and radiation (for more than four weeks), had a hemoglobin level higher than 10 g/dL, and were neither receiving antidepressants nor were depressed on a screening question. The controls were screened for depression and matched by age, gender, and body mass index. Neuromuscular testing involved a sustained submaximal elbow flexion contraction (SC) at 30% maximal level (30% maximum elbow flexion force). Endurance time (ET) was measured from the beginning of the SC to the time when participants could not maintain the SC. Evoked twitch force (TF), a measure of muscle fatigue, and compound action potential (M-wave), an assessment of neuromuscular-junction transmission were performed during the SC. Compared with controls, the CRF group had a higher BFI score (P<0.001), a shorter ET (P<0.001), and a greater TF with the SC (CRF>controls, P<0.05). This indicated less muscle fatigue. There was a greater TF (P<0.05) at the end of the SC, indicating greater central fatigue, in the CRF group, which failed to recruit muscle (to continue the SC), as well as the controls. M-Wave amplitude was lower in the CRF group than in the controls (P<0.01), indicating impaired neuromuscular junction conduction with CRF unrelated to central fatigue (M-wave amplitude did not change with SC). These data demonstrate that CRF patients exhibited greater central fatigue, indicated by shorter ET and less voluntary muscle recruitment during an SC relative to controls.
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Zhu ZY, Wang CM, Lo LC, Lin G, Feng F, Tan J, Chou R, Lim HS, Orban L, Yue GH. A standard panel of microsatellites for Asian seabass (Lates calcarifer). Anim Genet 2009; 41:208-12. [PMID: 19793264 DOI: 10.1111/j.1365-2052.2009.01973.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Microsatellites are the most popular markers for parentage assignment and population genetic studies. To meet the demand for international comparability for genetic studies of Asian seabass, a standard panel of 28 microsatellites has been selected and characterized using the DNA of 24 individuals from Thailand, Malaysia, Indonesia and Australia. The average allele number of these markers was 10.82 +/- 0.71 (range: 6-19), and the expected heterozygosity averaged 0.76 +/- 0.02 (range: 0.63-1.00). All microsatellites showed Mendelian inheritance. In addition, eight standard size controls have been developed by cloning a set of microsatellite alleles into a pGEM-T vector to calibrate allele sizes determined by different laboratories, and are available upon request. Seven multiplex PCRs, each amplifying 3-5 markers, were optimized to accurately and rapidly genotype microsatellites. Parentage assignment using 10 microsatellites in two crosses (10 x 10 and 20 x 20) demonstrated a high power of these markers for revealing parent-sibling connections. This standard set of microsatellites will standardize genetic diversity studies of Asian seabass, and the multiplex PCR sets will facilitate parentage assignment.
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Lu WS, Huang MH, Tian ZM, Yu X, Zhao QJ, Wang YM, Zhao HL, Sun JZ, Yue GH. Improved Diagnosis of Intracranial Mass Lesions by Proton MR Spectroscopy. Neuroimage 2009. [DOI: 10.1016/s1053-8119(09)70394-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Fang Y, Daly JJ, Sun J, Hvorat K, Fredrickson E, Pundik S, Sahgal V, Yue GH. Functional corticomuscular connection during reaching is weakened following stroke. Clin Neurophysiol 2009; 120:994-1002. [PMID: 19362515 PMCID: PMC2680928 DOI: 10.1016/j.clinph.2009.02.173] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2008] [Revised: 02/20/2009] [Accepted: 02/25/2009] [Indexed: 10/20/2022]
Abstract
OBJECTIVE To investigate the functional connection between motor cortex and muscles, we measured electroencephalogram-electromyogram (EEG-EMG) coherence of stroke patients and controls. METHODS Eight healthy controls and 21 patients with shoulder and elbow coordination deficits were enrolled. All subjects performed a reaching task involving shoulder flexion and elbow extension. EMG of the anterior deltoid (AD) and brachii muscles (BB, TB) and 64-channel scalp EEG were recorded during the task. Time-frequency coherence was calculated using the bivariate autoregressive model. RESULTS Stroke patients had significantly lower corticomuscular coherence compared with healthy controls for the AD and BB muscles at both the beta (20-30 Hz) and lower gamma (30-40 Hz) bands during the movement. BH procedure (FDR) identified a reduced corticomuscular coherence for stroke patients in 11 of 15 scalp area-muscle combinations. There was no statistically significant difference between stroke patients and control subjects according to coherence in other frequency bands. CONCLUSION Poorly recovered stroke survivors with persistent upper-limb motor deficits exhibited significantly lower gamma-band corticomuscular coherence in performing a reaching task. SIGNIFICANCE The study suggests poor brain-muscle communication or poor integration of the EEG and EMG signals in higher frequency band during reaching task may reflect an underlying mechanism producing movement deficits post-stroke.
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Yao B, Liu JZ, Brown RW, Sahgal V, Yue GH. Nonlinear features of surface EEG showing systematic brain signal adaptations with muscle force and fatigue. Brain Res 2009; 1272:89-98. [PMID: 19332036 DOI: 10.1016/j.brainres.2009.03.042] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2008] [Revised: 03/17/2009] [Accepted: 03/17/2009] [Indexed: 11/25/2022]
Abstract
Nonlinear dynamics has been introduced to the analysis of biological data and increasingly recognized to be functionally relevant. The purpose of this study was to examine chaotic properties of human scalp EEG signals associated with voluntary motor tasks using the largest Lyapunov exponent (L1). 64-channel scalp EEG data were recorded from eight healthy subjects in two tasks: (1) intermittent handgrip contractions at 20, 40, 60, and 80% of maximal voluntary contraction (MVC) with 20 trials at each level. No significant fatigue were induced; (2) intermittent handgrip MVCs (100 trials) that resulted in significant fatigue. The L1 values of all EEG channels were calculated in each trial first then averaged across the 20 trials at each force level (Task 1) or over each of the 5-trial blocks (Task 2) before the group means were obtained. A multivariate statistical model was used to examine the effect of force and fatigue on L1. L1 values were greater with higher force (Task 1), and decreased significantly with fatigue (Task 2). The L1 of the EEG signals changes systematically and correlates significantly with muscle force and fatigue. The results suggest that nonlinear chaotic index L1 may serve as a quantitative measure for motor control-related cortical signal adaptations.
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Yue GH, Wang LS, Wang X, Chen YZ, Peng DL. Characterization and Optical Properties of the Single Crystalline SnS Nanowire Arrays. NANOSCALE RESEARCH LETTERS 2009; 4:359-363. [PMID: 20596376 PMCID: PMC2894107 DOI: 10.1007/s11671-009-9253-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2008] [Accepted: 01/08/2009] [Indexed: 05/26/2023]
Abstract
The SnS nanowire arrays have been successfully synthesized by the template-assisted pulsed electrochemical deposition in the porous anodized aluminum oxide template. The investigation results showed that the as-synthesized nanowires are single crystalline structures and they have a highly preferential orientation. The ordered SnS nanowire arrays are uniform with a diameter of 50 nm and a length up to several tens of micrometers. The synthesized SnS nanowires exhibit strong absorption in visible and near-infrared spectral region and the direct energy gap E(g) of SnS nanowires is 1.59 eV.
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Yang Q, Fang Y, Sun CK, Siemionow V, Ranganathan VK, Khoshknabi D, Davis MP, Walsh D, Sahgal V, Yue GH. Weakening of functional corticomuscular coupling during muscle fatigue. Brain Res 2008; 1250:101-12. [PMID: 19028460 DOI: 10.1016/j.brainres.2008.10.074] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2008] [Revised: 10/20/2008] [Accepted: 10/22/2008] [Indexed: 10/21/2022]
Abstract
OBJECTIVE Recent research has shown dissociation between changes in brain and muscle signals during voluntary muscle fatigue, which may suggest weakening of functional corticomuscular coupling. However, this weakening of brain-muscle coupling has never been directly evaluated. The purpose of this study was to address this issue by quantifying EEG-EMG coherence at times when muscles experienced minimal versus significant fatigue. METHODS Nine healthy subjects sustained an isometric elbow flexion at 30% maximal level until exhaustion while their brain (EEG) and muscle (EMG) activities were recorded. The entire duration of the EEG and EMG recordings was divided into the first half (stage 1 with minimal fatigue) and second half (stage 2 with severer fatigue). The EEG-EMG coherence and power spectrum in each stage was computed. RESULTS The power of both EEG and EMG increased significantly while their coherence decreased significantly in stage 2 compared with stage 1 at beta (15-35 Hz) band. CONCLUSIONS Despite an elevation of the power for both the EEG and EMG activities with muscle fatigue, the fatigue weakens strength of brain-muscle signal coupling at beta frequency band. SIGNIFICANCE Weakening of corticomuscular coupling may be a major neural mechanism contributing to muscle fatigue and associated performance impairment.
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Zhu ZY, Wang CM, Feng F, Yue GH. Isolation and characterization of 51 microsatellites from BAC clones in Asian seabass, Lates calcarifer. Anim Genet 2008; 40:125-6. [PMID: 18945291 DOI: 10.1111/j.1365-2052.2008.01797.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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65
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Wang XF, Yang Q, Fan Z, Sun CK, Yue GH. Assessing time-dependent association between scalp EEG and muscle activation: A functional random-effects model approach. J Neurosci Methods 2008; 177:232-40. [PMID: 18977246 DOI: 10.1016/j.jneumeth.2008.09.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2008] [Revised: 09/25/2008] [Accepted: 09/25/2008] [Indexed: 10/21/2022]
Abstract
This study investigates time-dependent associations between source strength estimated from high-density scalp electroencephalogram (EEG) and force of voluntary handgrip contraction at different intensity levels. We first estimate source strength from raw EEG signals collected during voluntary muscle contractions at different levels and then propose a functional random-effects model approach in which both functional fixed effects and functional random-effects are considered for the data. Two estimation procedures for the functional model are discussed. The first estimation procedure is a two-step method which involves no iterations. It can flexibly use different smoothing methods and smoothing parameters. The second estimation procedure benefits from the connection between linear mixed models and regression splines and can be fitted using existing software. Functional ANOVA is then suggested to assess the experimental effects from the functional point of view. The statistical analysis shows that the time-dependent source strength function exhibits a nonlinear feature, where a bump is detected around the force onset time. However, there is the lack of significant variations in source strength on different force levels and different cortical areas. The proposed functional random-effects model procedure can be applied to other types of functional data in neuroscience.
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Yue GH, Wang GL, Zhu BQ, Wang CM, Zhu ZY, Lo LC. Discovery of four natural clones in a crayfish species Procambarus clarkii. Int J Biol Sci 2008; 4:279-82. [PMID: 18781225 PMCID: PMC2532795 DOI: 10.7150/ijbs.4.279] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Accepted: 08/26/2008] [Indexed: 11/08/2022] Open
Abstract
Self-cloning is quite rare in shrimp, lobsters, crayfish and crabs. Here we report the discovery of four natural clones of red swamp crayfish (Procambarus clarkii), each containing 2-6 genetically identical individuals, during the genotyping of 120 individuals with five microsatellites. The four clones were heterozygote at most of the five microsatellite loci. Phylogenetic analysis using microsatellite genotypes suggests recent origin of the four clones. Sequencing a part of the mitochondrial gene Cox I confirmed that the four clones were from the species Procambarus clarkii.
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Khoshknabi DS, Davis MP, Ranganathan VK, Siemionow V, Walsh D, Kirkova J, Yue GH. Combining Objective and Subjective Outcomes in Cancer-Related Fatigue: Illustrations from a Single Case Report. J Palliat Med 2008; 11:829-33. [DOI: 10.1089/jpm.2007.0295] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Yue GH, Yan PX, Wang LS, Wang W, Chen YZ, Peng DL. Finite-size effect on magnetic properties in iron sulfide nanowire arrays. NANOTECHNOLOGY 2008; 19:195706. [PMID: 21825724 DOI: 10.1088/0957-4484/19/19/195706] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We report the size effect on the magnetic properties in Fe(7)S(8) nanowire arrays. Samples with diameters in the range of 50-200 nm have been prepared by electrodeposition with AAO films. The Mössbauer measurement results show that four parameters (hyperfine fields, isomer shift, quadrupole splitting, full width at half-maximum) increased with decreasing the diameter of the nanowires. The magnetic properties were investigated. The hysteresis loop shape and the magnetization are dependent on the diameter of the nanowires. The thermomagnetic measurements on the as-synthesized nanowire samples and the corresponding bulk display a mixed-type curve and a Weiss-type curve, respectively.
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Wang X, Sun J, Gustafson KJ, Yue GH. Modeling heterogeneity and dependence for analysis of neuronal data. Stat Med 2008; 26:3927-2945. [PMID: 17577244 DOI: 10.1002/sim.2943] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In this paper, we describe two types of neuroscience problems which challenge the typical statistical models assumed for analyzing neuronal data. This offers an opportunity for new modeling and statistical inference. In the first problem, the data are spatial neural counts which are often over-dispersed and spatially correlated so that a standard Poisson regression model is inadequate. In the second problem, the data are averaged electroencephalograph signals recorded during muscle fatigue, where a time series AR(1) regression model cannot fully capture all the variation and correlation structure in the data. It is shown that an additional parameter has to be included in the modeling of the correlation structure and that the role of the parameter differs from one channel to the other. We propose appropriate generalized models for these data, develop statistical procedures under the generalized models, and apply these procedures to the real data that motivated this paper. The effect of mis-specification of a correlation structure is also investigated.
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Lo LC, Yue GH. Microsatellites for broodstock management of the Tiger grouper, Epinephelus fuscoguttatus. Anim Genet 2007; 39:90-1. [PMID: 18076741 DOI: 10.1111/j.1365-2052.2007.01675.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Wang CM, Lo LC, Feng F, Zhu ZY, Yue GH. Identification and verification of QTL associated with growth traits in two genetic backgrounds of Barramundi (Lates calcarifer). Anim Genet 2007; 39:34-9. [PMID: 18076743 DOI: 10.1111/j.1365-2052.2007.01672.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Quantitative trait loci (QTL) affecting growth traits have previously been mapped in linkage groups (LG) 2, 3 and 23 of Barramundi (Lates carcalifer), but these QTL have not been verified in different genetic backgrounds and environments. Here, we report the identification and verification of QTL for growth traits on LG2, 3, 10 and 23 in F(1) families constructed using brooders from the Singapore Marine Aquaculture Center (MAC) and from wild stocks collected in Thailand (THAI). The previously detected QTL for body weight and length linked to marker Lca371 on LG2 were confirmed in both the MAC and THAI families, whereas other QTL previously mapped to LG3 and 23 were only detected in one of the two families. QTL for body weight and length were identified in the MAC family, but not in the THAI family, in a region where the insulin-like growth factor 2 (IGF2) and tyrosine hydroxylase 1 (TH1) genes are located on LG10. Significant epistatic interactions were identified between markers Lca287 on LG2 and IGF2 on LG10 for growth trait QTL in the MAC family, but not in the THAI family. Effects of the IGF2, TH1 and parvalbumin 1 candidate genes were family-specific. Our results indicate that some but not all QTL are family-specific in Barramundi.
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Zhang L, Dean D, Liu JZ, Sahgal V, Wang X, Yue GH. Quantifying degeneration of white matter in normal aging using fractal dimension. Neurobiol Aging 2007; 28:1543-55. [PMID: 16860905 DOI: 10.1016/j.neurobiolaging.2006.06.020] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2005] [Revised: 05/05/2006] [Accepted: 06/19/2006] [Indexed: 11/28/2022]
Abstract
Although degeneration of brain white matter (WM) in aging is a well-recognized problem, its quantification has mainly relied on volumetric measurements, which lack detail in describing the degenerative adaptation. In this study, WM structural complexity was evaluated in healthy old and young adults by analyzing the three-dimensional fractal dimension (FD) of WM segmented from magnetic resonance images of brain. FDs detected in the old were significantly smaller than in the young subjects. Specifically, WM interior structure complexity degenerated in the left hemisphere in old men but in the right hemisphere in old women. Men showed more complex WM patterns than women. An asymmetrical (right-greater-than-left-hemisphere) complexity pattern was observed in the interior and general structures of WM, yet the surface complexity was symmetrical across WM structures of the two hemispheres. WM volumes were also measured, but no significant decline was found with aging. These results suggest that the deterioration of WM complexity is not uniformly distributed between the genders and across brain hemispheres.
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Fang Y, Yue GH, Hrovat K, Sahgal V, Daly JJ. Abnormal cognitive planning and movement smoothness control for a complex shoulder/elbow motor task in stroke survivors. J Neurol Sci 2007; 256:21-9. [PMID: 17391704 DOI: 10.1016/j.jns.2007.01.078] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2006] [Revised: 01/05/2007] [Accepted: 01/23/2007] [Indexed: 11/23/2022]
Abstract
PURPOSE Cortical function is not well understood in stroke survivors with persistent dyscoordination. The study purpose was two-fold: 1) characterize cognitive planning time and cognitive effort level for a circle-drawing motor task in stroke survivors using shoulder/elbow muscles and 2) identify the relationship between cognitive effort level and movement smoothness. METHODS Twelve stroke survivors with shoulder/elbow coordination deficits (>12 mo) and eight controls were enrolled. The motor task was to draw a circle on a horizontal surface using only shoulder/elbow muscles. Outcome measures were: EEG-derived cognitive planning time, cognitive effort level, and movement smoothness. Comparisons between stroke and controls were made using t-tests. The Pearson's correlation model was analyzed to determine the relationship between movement smoothness and cognitive effort level. RESULTS Stroke subjects showed a statistically significant prolonged motor planning time versus controls for both lesion and non-lesion sides (p=0.013 and 0.049, respectively). They also showed a statistically significant elevated effort level versus controls for both sides (p=0.016 and 0.013). The patients exhibited statistically significant poor movement smoothness in the medial/lateral and forward/backward movement directions versus controls (p=0.035 and 0.037, respectively). For stroke, there was a significant correlation between cognitive effort level on the non-lesion side and smoothness of movement in the medial/lateral and forward/backward directions (r=0.54, p=0.036 and r=0.76, p=0.002, respectively). On the lesion side, results were mixed (r=0.268, p=0.2 r=0.59, p=0.023, respectively). CONCLUSIONS Stroke survivors with upper limb motor deficits exhibit a longer cognitive planning time and elevated cognitive effort for performance of a complex shoulder/elbow motor coordination task. The elevated cognitive effort level was associated with poor (jerky) motor performance, suggesting a potential role of the CNS in controlling movement smoothness of the arm.
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Liu JZ, Lewandowski B, Karakasis C, Yao B, Siemionow V, Sahgal V, Yue GH. Shifting of activation center in the brain during muscle fatigue: an explanation of minimal central fatigue? Neuroimage 2007; 35:299-307. [PMID: 17236789 PMCID: PMC2701907 DOI: 10.1016/j.neuroimage.2006.09.050] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2006] [Revised: 09/20/2006] [Accepted: 09/25/2006] [Indexed: 11/17/2022] Open
Abstract
Accumulating evidence suggests that the overall level of cortical activation controlling a voluntary motor task that leads to significant muscle fatigue does not decrease as much as the activation level of the motoneuron pool projecting to the muscle. One possible explanation for this "muscle fatigue>cortical fatigue" phenomenon is that the brain is an organ with built-in redundancies: it has multiple motor centers and parallel pathways, and the center of activation may shift from one location to another when neurons in the previous location become fatigued. This hypothesis was tested by estimating the changes of source locations of high-density (64 channels) scalp electroencephalographic (EEG) signals collected during both fatigue and non-fatigue motor tasks. A current dipole model was used to estimate the EEG sources. The fatigue motor task induced significant muscle fatigue, and the non-fatigue task did not. The EEG signal source that indicated the center of brain activation showed substantial location shifts during the fatigue motor task. The shifts could not be explained by variations of source locations caused by error estimated from the non-fatigue task EEG and simulated data. Compared to the non-fatigue condition, the weighted-center of the source locations for all the participants shifted toward the right hemisphere (ipsilateral to the muscle activation), anterior, and inferior cortical regions under the fatigue condition. Fatigue did not alter dipole (source-signal) strength or the overall level of brain activation. The brain may avoid fatigue by shifting neuron populations that participate in a fatiguing motor task.
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Zhu ZY, Wang CM, Lo LC, Feng F, Lin G, Yue GH. Isolation, characterization, and linkage analyses of 74 novel microsatellites in Barramundi (Lates calcarifer). Genome 2007; 49:969-76. [PMID: 17036072 DOI: 10.1139/g06-080] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Barramundi (Lates calcarifer) is an important marine food fish species in Southeast Asia and Australia. Seventy-four novel microsatellites were isolated from a genomic DNA library enriched for CA repeats and were characterized in 24 unrelated individuals. Among the 74 microsatellites, 71 were polymorphic, with an average allele number of 7.0 +/- 3.6/locus. The average expected heterozygosity of these polymorphic markers was 0.66. Sixty-three of the 71 polymorphic microsatellites conformed to Hardy-Weinberg equilibrium. Linkage analyses were conducted in a reference family, leading to the assignment of 34 novel microsatellites and 16 published markers in 16 linkage groups. The novel microsatellites developed in this study will contribute significantly to the construction of a first-generation linkage map for mapping of quantitative trait loci in Barramundi, and supply a large choice of markers for studies on population genetics, stock management, and pedigree reconstruction.
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