587 research outputs found

    Cerebellum to motor cortex paired associative stimulation induces bidirectional STDP-like plasticity in human motor cortex

    Get PDF
    The cerebellum is crucially important for motor control and adaptation. Recent non-invasive brain stimulation studies have indicated the possibility to alter the excitability of the cerebellum and its projections to the contralateral motor cortex, with behavioral consequences on motor control and adaptation. Here we sought to induce bidirectional spike-timing dependent plasticity (STDP)-like modifications of motor cortex (M1) excitability by application of paired associative stimulation (PAS) in healthy subjects. Conditioning stimulation over the right lateral cerebellum (CB) preceded focal transcranial magnetic stimulation (TMS) of the left M1 hand area at an interstimulus interval of 2 ms (CB→M1 PAS(2 ms)), 6 ms (CB→M1 PAS(6 ms)) or 10 ms (CB→M1 PAS(10 ms)) or randomly alternating intervals of 2 and 10 ms (CB→M1 PAS(Control)). Effects of PAS on M1 excitability were assessed by the motor-evoked potential (MEP) amplitude, short-interval intracortical inhibition (SICI), intracortical facilitation (ICF) and cerebellar-motor cortex inhibition (CBI) in the first dorsal interosseous muscle of the right hand. CB→M1 PAS(2 ms) resulted in MEP potentiation, CB→M1 PAS(6 ms) and CB→M1 PAS(10 ms) in MEP depression, and CB→M1 PAS(Control) in no change. The MEP changes lasted for 30-60 min after PAS. SICI and CBI decreased non-specifically after all PAS protocols, while ICF remained unaltered. The physiological mechanisms underlying these MEP changes are carefully discussed. Findings support the notion of bidirectional STDP-like plasticity in M1 mediated by associative stimulation of the cerebello-dentato-thalamo-cortical pathway and M1. Future studies may investigate the behavioral significance of this plasticity

    Relationship between management practice and organisation performance under European Union directives such as RoHS: A case-study of the electrical and electronic industry in Taiwan

    Get PDF
    The aim of this study is to investigate the effects of the European Union Restriction of Hazardous Substances (RoHS) and Waste Electrical and Electronic Equipment (WEEE) directives set by the European Union on the financial and environmental performances of Taiwan’s electrical and electronic companies adopting the green supply chain management. A literature review, in-depth interviews and questionnaires were used as our hypothetical supports. One hundred and fifty-one certified International Organization for Standardization 14001 electrical and electronic companies were randomly selected as the study subjects. Data analyses and hypothesis tests were performed using Statistical Package for the Social Sciences software, and Structural Equation Modelling was used to analyse the pathway model and to test the hypothetical structure in this study. We found that these companies mostly adopted green manufacturing practices and green purchasing practices in order to meet the RoHS and WEEE directives. The results of pathway diagram analysis using structural equation modelling (SEM) also showed that the green supply chain management adopted by the study companies had a positive effect on both their financial (p < 0.01) and environmental (p < 0.01) performances, and therefore might be used as a reference for Original Equipment Manufacturing and Original Designing and Manufacturing industries in other Asian Pacific countries.Keywords: RoHS, WEEE, green supply chain management, financial performance, environmental performanc

    Maternal Demographic and Psychosocial Factors Associated with Low Birth Weight in Eastern Taiwan

    Get PDF
    The relationship between birth weight and maternal sociodemographic characteristics was examined in a sample from two teaching hospitals in eastern Taiwan. Using a structured questionnaire, we conducted face- to-face interviews with women at antenatal clinics between 1998 and 1999 in Hualien City. One year later, we took the outcome of pregnancy from medical records and birth certificates from the Public Health Bureau of Hualien County. Of the 1,128 single live births, 6.8% had low birth weight (LBW) using the World Health Organization cut-off of 2,500 g. LBW was more common in teenage (< 20 years), older (> 30 years), first-time, and unmarried mothers; those with basic/intermediate educational attainment; and residents of aboriginal districts. Teenage pregnancies were more likely than those in adults to be unplanned, and such mothers had smoking or alcohol-drinking behavior. Prevention of teenage pregnancy is crucial to lower LBW rates in eastern Taiwan. For adult mothers, basic or intermediate educational attainment, residence in an aboriginal district, and first-term pregnancy were significant factors associated with LBW, after adjustment for other psychosocial attributes, such as psychologic distress and poor family support. Thus, we should pay more attention when caring for pregnant women with such sociodemographic characteristics, and ensure that they have adequate prenatal care and can adopt a healthy lifestyle

    Two-stage assembly system with imperfect items for a coordinated two-level integrated supply chain under carbon emission constraints

    Get PDF
    This paper may provide an alternative to the problem of a two-stage assembly system with imperfect processes in a single manufacturer-retailer and two-level integrated supply chain. A mathematical model is developed based on the following scenarios: (a) the manufacturer and the retailer are in different countries where the exchange rate is uncertain; (b) the fixed and variable carbon emission costs are incorporated into current environmental issues; (c) shortage is allowed, and the unsatisfied demand is completely backlogged. In the light of these concerns, our model is to determine the production run time, the shortage time period and defective rate of manual stage. The optimal solutions are computed by our proposed algorithm. Finally, a numerical example and sensitivity analysis are carried out to illustrate the model

    Paired Associative Electroacupuncture and Transcranial Magnetic Stimulation in Humans

    Get PDF
    Pairing transcutaneous electric nerve stimulation (TENS) and transcranial magnetic stimulation (TMS) with specific stimulus-intervals induces associative motor plasticity at the primary motor cortex (M1). Electroacupuncture (EA) is an established medical technique in the eastern countries. This study investigates whether EA paired with TMS induces distinct M1 motor plasticity. Fifteen healthy, right-handed subjects (aged 23.6 ± 2.0 years, eight women) were studied. Two-hundred and twenty-five pairs of TMS of the left M1 preceded by right EA at acupoint “Neiguan” [Pericardium 6 (PC6), located 2 decimeters proximal from the wrist wrinkle] were respectively applied with the interstimulus interval (ISI) of individual somatosensory evoked potential (SSEP) N20 latency plus 2 ms (N20+2) and minus 5 ms (N20-5) with at least 1-week interval. The paired stimulation was delivered at a rate of 0.25 Hz. Sham TMS with a sham coil was adopted to examine the low-frequency EA influence on M1 in eleven subjects. M1 excitability was assessed by motor-evoked potential (MEP) recruitment curve with five TMS intensity levels, short-interval intracortical inhibition (SICI), intracortical facilitation (ICF) and cerebellar inhibition (CBI) at the abductor pollicis brevis (APB) muscle of the right hand before and after the EA-M1 paired associative stimulation (PAS). In addition, median nerve SSEPs and H-reflex were respectively measured to monitor somatosensory and spinal excitability. The MEP showed significantly facilitated after the sham EA-M1 PAS while tested with 80% of the TMS intensity producing on average 1 mV amplitude (i.e., MEP1 mV) in the resting APB muscle. It was also facilitated while tested with 90% MEP1 mV irrespective of the stimulation conditions. The SSEP showed a higher amplitude from the real EA-M1 PAS compared to that from the sham EA-M1 PAS. No significant change was found on SICI, ICF, CBI and H-reflex. Findings suggest that repetitive low frequency EA paired with real TMS did not induce spike-timing dependent motor plasticity but EA paired with sham TMS induced specific M1 excitability change. Complex sensory afferents with dispersed time locked to the sensorimotor cortical area could hamper instead of enhancing the induction of the spike-timing dependent plasticity (STDP) in M1

    Sympathetic-correlated c-Fos expression in the neonatal rat spinal cord in vitro

    Get PDF
    An isolated thoracic spinal cord of the neonatal rat in vitro spontaneously generates sympathetic nerve discharge (SND) at ~25°C, but it fails in SND genesis at ≀ 10°C. Basal levels of the c-Fos expression in the spinal cords incubated at ≀ 10°C and ~25°C were compared to determine the anatomical substrates that might participate in SND genesis. Cells that exhibited c-Fos immunoreactivity were virtually absent in the spinal cords incubated at ≀ 10°C. However, in the spinal cords incubated at ~25°C, c-Fos-positive cells were found in the dorsal laminae, the white matter, lamina X, and the intermediolateral cell column (IML). Cell identities were verified by double labeling of c-Fos with neuron-specific nuclear protein (NeuN), glial fibrillary acidic protein (GFAP), or choline acetyltransferase (ChAT). The c-Fos-positive cells distributed in the white matter and lamina X were NeuN-negative or GFAP-positive and were glial cells. Endogenously active neurons showing c-Fos and NeuN double labeling were scattered in the dorsal laminae and concentrated in the IML. Double labeling of c-Fos and ChAT confirmed the presence of active sympathetic preganglionic neurons (SPNs) in the IML. Suppression of SND genesis by tetrodotoxin (TTX) or mecamylamine (MECA, nicotinic receptor blocker) almost abolished c-Fos expression in dorsal laminae, but only mildly affected c-Fos expression in the SPNs. Therefore, c-Fos expression in some SPNs does not require synaptic activation. Our results suggest that spinal SND genesis is initiated from some spontaneously active SPNs, which are capable of TTX- or MECA-resistant c-Fos expression

    Minimally invasive strategy for gynecologic cancer with solitary periacetabular metastasis

    Get PDF
    SummaryTumor with bone metastases to the periacetabulum is rare, and its surgical management is challenging. Instead of wide excision with reconstruction of the hip joint, we used a relatively noninvasive method to manage periacetabular metastasis. Such a procedure for this condition has the benefits of short surgical time, less bleeding, and fewer complications during surgery. Our surgical management of the case reported here included curettage, phenol cauterization and filling of cisplatin-loaded cement in order to reduce local recurrence. After following-up for 2 years, there was no local recurrence and disease progression

    Power-efficient memory bus encoding using stride-based stream reconstruction

    Get PDF
    With the rapid increase in the complexity of chips and the popularity of portable devices, the performance demand is not any more the only important constraint in the embedded system. In stead, energy consumption has become one of the main design issues for contemporary embedded systems, especially for I/O interface due to the high capacitance of bus transition. In this paper, we propose a bus encoding scheme, which may reduce transitions by reconstructing active address streams with variable cached strides. The key idea is to obtain the variable strides for dierent sets of active addressing streams such that the decoder reconstructs these interlaced streams with these strides. Instead of sending the full address, the encoder may only send partial ad- dress or stride by using either one-hot or binary-inversion encoding. To exploit the locality and dynamically adjust the value of stride of active address streams, we partially compare the previous addresses of existing streams with the current address. Hence, the data transmitted on the bus can be minimally encoded. Experiments with several MediaBench benchmarks show that the scheme can achieve an average of 60% reduction in bus switching activity.Facultad de InformĂĄtic
    • 

    corecore