Function Of Motor Speed Research Articles

Brain structural–functional coupling mechanism in mild subcortical stroke and its relationship with cognition

ObjectivesStroke can lead to significant restructuring of brain structure and function. However, the precise changes in the coordination between brain structure and function in subcortical stroke patients remain unclear. We investigated alterations in brain structural–functional coupling (SC-FC coupling) and their impact on cognitive function in subcortical basal ganglia infarction patients. MethodsThe study comprised 40 patients with mild stroke with basal ganglia region infarcts and 29 healthy controls (HC) who underwent multidimensional neuroimaging examination and neuropsychological testing. The subcortical stroke patients were divided into post-stroke cognitive impairment (PSCI) and stroke with no cognitive impairment (NPSCI) groups based on cognitive performance, with 22 individuals undergoing follow-up examination after three months. We investigated differences in brain structural–functional coupling across three groups, and their associations with cognitive functions. ResultsCompared to both HC participants and NPSCI, PSCI exhibited significantly reduced structural–functional coupling strength in specific brain regions. After a three-month period, there was observed an increase in structural–functional coupling strength within the frontal lobe (precentral gyrus and paracentral lobule). The strength of SC-FC coupling within the precentral gyrus, precuneus, and paracentral lobule regions demonstrated a decline correlating with the deterioration of cognitive function (MoCA, memory and visual motor speed functions). ConclusionsAfter subcortical basal ganglia stroke, PSCI patients demonstrated decreased SC-FC coupling in the frontal lobe region, correlating with multidimensional cognitive impairment. Three months later, there was an increase in SC-FC coupling in the frontal lobe, suggesting a compensatory mechanism during the recovery phase of cognitive impairment following stroke.

Optical rotary junction incorporating a hollow shaft DC motor for high-speed catheter-based optical coherence tomography

In intravascular optical coherence tomography (OCT), the optical rotary junction plays an important role in rotating and pulling back the catheter to generate cross-sectional coronary artery images. To meet the requirements of high-speed intravascular OCT in a clinical setting, the rotary junction should generate high torque and low vibration. In this Letter, we demonstrate an ultrahigh speed optical rotary junction incorporating a hollow shaft brushless DC servomotor to remove a pulley belt, or a gear to minimize vibration noise and transfer stable torque. To evaluate the performance of the rotary junction, the vibration noise and variation of rotation were measured as a function of motor speed. The results showed that the rotary junction rotated the catheter at 42,000 revolutions per minute, with an optical transmission loss of 1.2 dB. To assess the feasibility of the rotary junction for high-speed catheter-based OCT, OCT imaging of the cylindrical shape of a phantom made by two overlapped plastic straws was performed at a rate of 200 frames/s.

Mentally Challenged Children’s Performance Comparison to Evaluate their Motor Function of the Brain – By Applying Finger Tapping Sub-test Test of Neuropsychological Battery

“Mentally challenged children’s performance comparison to evaluate their brain’s motor function – by applying finger tapping subtest test of neuropsychological battery” this is a research problem to know that mental retardation is affecting their motor co-ordination function on not”. Neuro-psychological assessment test battery which was developed by NIMHANS, Bangalore in the year of 2004 and its sub-test Finger tapping test was administered for research. By random sampling method, samples were collected from B.M Institute of Mental Health, Ahmedabad in the year of 2012. Based on Government Civil hospital’s IQ certificate 75 mild category of MR children of above and below graduate parents were taken for research with prior permission. Mental Retardation based on various diagnosis like; Down syndrome, microcephaly, hydrocephaly, trisomy-13, trisomy-18 or multiple disabilities are included. Flowingly, Children’s age group and gender are also kept different to compare their performance on finger tapping test. The results shows the “t” value of Neuropsychological functions of finger tapping test (Right hand) of mild children of different educational level of parents is 0.12. The mean scores of finger tapping test (Right hand) of mild children of above and below graduate parents were found 36.08 and 36.38 respectively with SD 8.50 and 12.56. The results indicate that significant difference does not exist between mild children of below and above graduate parents with regard to finger tapping test (Right hand). In the light of the hypothesis that there will be no significant difference between mild children of below and above graduate parents on finger tapping test (Right hand). It implies that mild children of below and above graduate parents have no significant difference of performance on finger tapping test (Right hand). Based on the result it depicts that mild children of below and above graduate parents’ children have similar performance on finger tapping test (Right hand). The results shows the “t” value of Neuropsychological functions of finger tapping test (Left hand) of mild children of educational level of parents is 0.55. The mean scores of finger tapping test (Left hand) of mild children of above graduate parents were found 34.49 and 35.92 respectively with SD 9.18 and 13.03. The results indicate that significant difference exist between mild children of below graduate parents and mild children of above graduate parents with regard to finger tapping test (Left hand). In the light of the hypothesis that there will be no significant difference between mild children of below and above graduate parents on finger tapping test (Left hand). It implies that mild children of below and above graduate parents have no significant difference on finger tapping test (left hand). Mild children of above and below graduate parent’s children have similar performance on finger tapping test (left hand). On the basis of result it is concluded that Mild MR category of above and below graduate parent’s children have similar performance on Finger tapping test in both Right and Left hand. It depicts that these children are fair in their motor function of motor speed and co-ordination. 75 children’s mental retardation does not affected on their brain’s motor function performance.

Association between cognitive deficits and suicidal ideation in patients with major depressive disorder

The role of cognitive function in suicidal ideation in patients with major depressive disorder (MDD) has not been adequately explored. This research sought to measure the relationship between suicidal ideation and cognitive function. Therefore, in this study, the association between cognitive function and suicidal ideation in patients with MDD was assessed. Cognitive function was evaluated in 233 patients with MDD using the Japanese version of the Brief Assessment of Cognition in Schizophrenia (BACS). Suicidal ideation was assessed using item 3 of the Hamilton Depression Rating Scale. Approximately 59.2% of the patients (138/233) expressed suicidal ideation. Among the BACS subtests, only the executive function scores were significantly lower in patients with MDD with than in those without (p < 0.005). In addition, the executive function, motor speed function, and composite scores correlated negatively with the severity of suicidal ideation in these patients. These results suggest that executive function, motor speed function, and global neuropsychological function are associated with suicidal ideation in patients with MDD and that the BACS neuropsychological battery is an efficient instrument for monitoring these characteristics. Moreover, specific BACS scores can potentially serve as cognitive biomarkers of suicide risk in patients with MDD.

Occupational pesticide exposure in early pregnancy associated with sex-specific neurobehavioral deficits in the children at school age

Prenatal exposure to pesticides may affect neurodevelopment, while the impact of modern pesticides is unclear. From 1997–2001, women working in greenhouse horticultures were recruited at the beginning of their pregnancy. Based on detailed interview of the women and their employers, those categorized as occupationally exposed to pesticides were moved to unexposed work functions or went on paid leave, while women without any exposure were considered unexposed controls. Of the resulting birth cohort of 203 children, 133 (65%) were examined at age 6 to 11years together with 44 newly recruited children of same age whose mothers were not occupationally exposed to pesticides in pregnancy. All children underwent a standardized examination including a battery of neurodevelopmental tests. Maternal occupational pesticide exposure in early pregnancy was associated with prolonged brainstem auditory evoked potential latencies in the children as a whole and with impaired neuropsychological function in girls, while no effect was apparent in boys. In girls, language and motor speed functions were significantly inversely associated with prenatal exposure, and a non-significant tendency toward decreased function was also seen for other neuropsychological outcomes. A structural equation model that combined all these test results showed an overall impaired neuropsychological function in girls prenatally exposed to pesticides. Thus, our findings suggest an adverse effect of maternal occupational pesticide exposure on their children's neurodevelopment, despite the fact that the exposures occurred solely during early pregnancy and under well regulated working conditions, where special measures to protect pregnant women were applied.

Nonequilibrium structure and dynamics in a microscopic model of thin-film active gels.

In the presence of adenosine triphosphate, molecular motors generate active force dipoles that drive suspensions of protein filaments far from thermodynamic equilibrium, leading to exotic dynamics and pattern formation. Microscopic modeling can help to quantify the relationship between individual motors plus filaments to organization and dynamics on molecular and supramolecular length scales. Here, we present results of extensive numerical simulations of active gels where the motors and filaments are confined between two infinite parallel plates. Thermal fluctuations and excluded-volume interactions between filaments are included. A systematic variation of rates for motor motion, attachment, and detachment, including a differential detachment rate from filament ends, reveals a range of nonequilibrium behavior. Strong motor binding produces structured filament aggregates that we refer to as asters, bundles, or layers, whose stability depends on motor speed and differential end detachment. The gross features of the dependence of the observed structures on the motor rate and the filament concentration can be captured by a simple one-filament model. Loosely bound aggregates exhibit superdiffusive mass transport, where filament translocation scales with lag time with nonunique exponents that depend on motor kinetics. An empirical data collapse of filament speed as a function of motor speed and end detachment is found, suggesting a dimensional reduction of the relevant parameter space. We conclude by discussing the perspectives of microscopic modeling in the field of active gels.

BEAST—A portable device for quantification of erosion in natural intact sediment cores

A portable Particle Erosion Simulator (PES) device, also referred to as the BEAST (Benthic Environmental Assessment Sediment Tool) (Walker et al., 2008) has been re-designed for quantifying erosion in natural intact sediment cores. The BEAST was re-configured from an older design (Tsai and Lick, 1986), which had uncalibrated flow characteristics and was limited to viewing resuspension. In addition to calibrating friction velocity at the sediment–water interface, we employ a combination of real-time turbidity monitoring (via measurement of % transmission which decreases proportionally to suspended solid concentration) to quantify erosion threshold and calculate erosion rate, as well as digital imaging to document sequences of erosion and particle size response of resuspended material. The BEAST consists of a clear acrylic Plexiglas™ core liner with a perforated disc oscillating vertically in a piston motion. Performance of the device was calibrated by (a) comparing predicted to observed friction velocity as a function of motor speed, (b) using a hot film anemometer in the chamber to measure shear velocity, (c) verifying the applicability of anemometric calibration by relating the power of the grid stroke to stress dissipation, and (d) comparing measured critical stress of foundry sand to predictions from a validated model. Measurements indicate the friction velocity is uniform over >50% of the radial distance from the core center. Bottom stress is highly sensitive to the final height of piston down-stroke, a variable that can be altered to control the range of friction velocities. A plot of piston motor RPM vs. predicted u∗ was identical to the regression fit through the observed data. We verified that the proportionality between power input and thermistor heat dissipation corresponds to the scaling of u∗ and RPM, consistent with our calibration using the stress sensor. An example of an erosion sequence is demonstrated from a field core obtained in the Beaufort Sea in which two erosion stages were clearly indicated in the combined results from measurements of % transmission (to determine turbidity), particle size, and erosion rate. Our studies confirm that the BEAST has predictable flow characteristics expected from first principles, and that applied shear stress causes erosion in a way quantitatively similar to horizontal shear. In addition, the predicted erosion threshold of sand-sized particles corresponds to within 3%–18% of measured values made using the device. These multiple sources of BEAST validation demonstrate its practical capability to provide quantitative field measurements of transport parameters from intact marine sediments if applied in a similar manner, and further contribute to predictive capability in modeling of benthic–pelagic coupling.

Modeling the heterogeneity in risk of progression to Alzheimer's disease acrosscognitive profiles in mild cognitive impairment

IntroductionHeterogeneity in risk of conversion to Alzheimer's disease (AD) among individuals with mild cognitive impairment (MCI) is well known. Novel statistical methods that are based on partially ordered set (poset) models can be used to create models that provide detailed and accurate information about performance with specific cognitive functions. This approach allows for the study of direct links between specific cognitive functions and risk of conversion to AD from MCI. It also allows for further delineation of multi-domain amnestic MCI, in relation to specific non-amnestic cognitive deficits, and the modeling of a range of episodic memory functioning levels.MethodsFrom the Alzheimer's Disease Neuroimaging Initiative (ADNI) study, conversion at 24 months of 268 MCI subjects was analyzed. It was found that 101 of those subjects (37.7%) converted to AD within that time frame. Poset models were then used to classify cognitive performance for MCI subjects. Respective observed conversion rates to AD were calculated for various cognitive subgroups, and by APOE e4 allele status. These rates were then compared across subgroups.ResultsThe observed conversion rate for MCI subjects with a relatively lower functioning with a high level of episodic memory at baseline was 61.2%. In MCI subjects who additionally also had relatively lower perceptual motor speed functioning and at least one APOE e4 allele, the conversion rate was 84.2%. In contrast, the observed conversion rate was 9.8% for MCI subjects with a relatively higher episodic memory functioning level and no APOE e4 allele. Relatively lower functioning with cognitive flexibility and perceptual motor speed by itself also appears to be associated with higher conversion rates.ConclusionsAmong MCI subjects, specific baseline cognitive profiles that were derived through poset modeling methods, are clearly associated with differential rates of conversion to AD. More precise delineation of MCI by such cognitive functioning profiles, including notions such as multidomain amnestic MCI, can help in gaining further insight into how heterogeneity arises in outcomes. Poset-based modeling methods may be useful for providing more precise classification of cognitive subgroups among MCI for imaging and genetics studies, and for developing more efficient and focused cognitive test batteries.

Cognitive Functions of Young Adults Who Survived Childhood Cancer

Neuropsychological tests were used to determine the cognitive functioning of adult long-term survivors treated for childhood cancer. Disease onset before the age of 5 was related to lower test scores in intelligence tests, several memory tests, and motor function tests. The cranial irradiated survivors displayed more difficulties, especially in short-term memory tests and the Wechsler Adult Intelligence Scale Digit Symbol Test as compared to nonradiated survivors. No statistically significant differences in test scores were observed between different forms of cancer. The results of this study are consistent with the notion that those memory types that demand special attention and motor speed functions are especially vulnerable to cancer and its treatment.

Cognitive Functions of Young Adults Who Survived Childhood Cancer

Neuropsychological tests were used to determine the cognitive functioning of adult long-term survivors treated for childhood cancer. Disease onset before the age of 5 was related to lower test scores in intelligence tests, several memory tests, and motor function tests. The cranial irradiated survivors displayed more difficulties, especially in short-term memory tests and the Wechsler Adult Intelligence Scale Digit Symbol Test as compared to nonradiated survivors. No statistically significant differences in test scores were observed between different forms of cancer. The results of this study are consistent with the notion that those memory types that demand special attention and motor speed functions are especially vulnerable to cancer and its treatment.

Fuzzy logic torque ripple reduction by turn-off angle compensation for switched reluctance motors

A fuzzy-logic-based turn-off angle compensator for torque ripple reduction in a switched reluctance motor is proposed. The turn-off angle, as a complex function of motor speed and current, is automatically changed for a wide motor speed range to reduce torque ripple. Experimental results are presented that show ripple reduction when the turn-off angle compensator is used.

Correlation of atrophy measures on MRI with neuropsychological sequelae in children and adolescents with traumatic brain injury

To examine the relationship between neuropsychological sequelae and atrophy parameters from magnetic resonance imaging (MRI) following paediatric moderate-to-severe traumatic brain injury (TBI), 19 head-injured children and adolescents were studied at least 6 years after injury. Three-dimensional MRI scans were obtained. A semi-automatic computerized method was used to estimate ventricular volumes and the corpus callosum area. Tests of intellectual, memory, visuospatial, frontal lobe, and motor speed functioning were administered to all patients and to 19 matched normal control subjects. Patients' performance significantly differed from controls in general intellectual function, visual memory, visuospatial and frontal lobe tests. The corpus callosum area correlated strongly with several measures involving processing speed and visuospatial function. Ventricular enlargement was less related to neuropsychological outcome. In conclusion, quantitative measurement of the corpus callosum on MRI reflects neuropsychological outcome better than ventricular dilation in paediatric patients.

96/03888 Decision steps for implementing a BACnet TM interface project

In this paper, several capacity-control schemes for conventional air-conditioning systems are discussed. An inverter-driven, variable-speed air-conditioner (VSAC), which allows continuous adjustment of system capacity, is investigated from an energy-conservation standpoint. Energy savings are estimated for a 100-m2 residence in Dhahran equipped with a 17.6-kW, fixed-speed air-conditioner (FSAC). The simulated VSAC is driven by three different power sources. The use of a sine-wave motor-generator set, which produces the highest motor efficiency as a function of motor speed, will save 29% of the 20,000 kWh consumed by the FSAC, which agrees within 5% of the annual measured. Pulse-width-modulated (PWM) and six-step inverter systems will provide energy savings of 19 and 23%, respectively. Simulation results indicate that VSACs will operate for 5500 h, while the fixed-speed system will run for 3200 h annually.

Capacity control of air-conditioning systems by power inverters

In this paper, several capacity-control schemes for conventional air-conditioning systems are discussed. An inverter-driven, variable-speed air-conditioner (VSAC), which allows continuous adjustment of system capacity, is investigated from an energy-conservation standpoint. Energy savings are estimated for a 100-m 2 residence in Dhahran equipped with a 17.6-kW, fixed-speed air-conditioner (FSAC). The simulated VSAC is driven by three different power sources. The use of a sine-wave motor-generator set, which produces the highest motor efficiency as a function of motor speed, will save 29% of the 20,000 kWh consumed by the FSAC, which agrees within 5% of the annual measured. Pulse-width-modulated (PWM) and six-step inverter systems will provide energy savings of 19 and 23%, respectively. Simulation results indicate that VSACs will operate for 5500 h, while the fixed-speed system will run for 3200 h annually.