253 research outputs found
The role of cooperatives in Chinese economic reconstruction since 1928
The study of Chinese economic and social problems requires that certain fundamental Chinese conditions be kept constantly in mind by the Western student, lest he attempt to analyze from the contemporary economic and social viewpoints of his own country. Accomplishments and plans must both be considered in relation to what has gone before and what is within the realm of possibility under given conditions, rather than by comparison with accomplishments and plans in other countries where the basic situation is entirely different.
The object of this paper is to place cooperatives in relation to the to the reconstruction as a whole, and to estimate the extent to which cooperatives are an effective instrument of economic reconstruction. As the Kuomintang or Nationalist Party has been the governing power in China since 1928, this study of necessity a description of cooperatives as a phase of reconstruction under the Kuomintang
Use of the Putamen/Caudate Volume Ratio for Early Differentiation between Parkinsonian Variant of Multiple System Atrophy and Parkinson Disease
BACKGROUND AND PURPOSE:
Neuropathological studies have demonstrated that multiple system atrophy (MSA) produces selective atrophy of the putamen with sparing of the caudate nucleus, while both structures are spared in idiopathic Parkinson's disease (PD). In this study we evaluated the clinical efficacy of using putaminal atrophy in brain MRI to differentiate MSA and PD.
METHODS:
We measured the putamen/caudate volume ratio on brain MRI in 24 patients with MSA and 21 patients with PD. Two clinicians who were blinded to the patients' diagnoses and to each other's assessments measured the volume ratio using a computer program.
RESULTS:
The measured volume ratios of the two investigators were highly correlated (r=0.72, p<0.0001). The volume ratio was significantly lower in MSA (1.29+/-0.28) than PD (1.91+/-0.29, p<0.0001). Setting an arbitrary cutoff ratio of 1.6 resulted in about 90% of patients with MSA falling into the group with a lower ratio, whereas more than 80% of patients with PD belonged to the other group.
CONCLUSIONS:
The present results demonstrate that putaminal atrophy in MSA as measured on brain MRI represents an effective tool for differentiating MSA from PD.ope
Impact of modern electronic equipment on the assessment of network harmonic impedance
Network harmonic impedance forms the link between harmonic currents emitted by individual devices and the harmonic voltage levels in the grid. It is essential for the definition of current emission limits in order to ensure Electromagnetic Compatibility between all equipment connected to the grid. Among all electrical equipment in future smart grid electronic devices, like PV inverters, EV chargers or lamps with electronic ballast, will have a dominating share. This is expected to have a considerable impact on the network harmonic impedance characteristic. The paper discusses the frequency-dependent input impedance of different types of modern electronic equipment and its potential impact on the network harmonic impedance. It is shown that the semiconductor switching results in a variation of the impedance within the fundamental cycle. This is not considered by the presently used assessment methods as they assume only passive network elements. Beside a method to measure these variations, several indices are introduced to quantify the level of its impact. The paper aims to provide some impulses for further discussions, particularly about the definition of network harmonic impedance in presence of electronic devices, the necessity to include these variations in realistic harmonic studies and if this has to be considered in the standardization
Developmental dyscalculia: compensatory mechanisms in left intraparietal regions in response to nonsymbolic magnitudes
BACKGROUND: Functional magnetic resonance imaging (fMRI) studies investigating the neural mechanisms underlying developmental dyscalculia are scarce and results are thus far inconclusive. Main aim of the present study is to investigate the neural correlates of nonsymbolic number magnitude processing in children with and without dyscalculia. METHODS: 18 children (9 with dyscalculia) were asked to solve a non-symbolic number magnitude comparison task (finger patterns) during brain scanning. For the spatial control task identical stimuli were employed, instructions varying only (judgment of palm rotation). This design enabled us to present identical stimuli with identical visual processing requirements in the experimental and the control task. Moreover, because numerical and spatial processing relies on parietal brain regions, task-specific contrasts are expected to reveal true number-specific activations. RESULTS: Behavioral results during scanning reveal that despite comparable (almost at ceiling) performance levels, task-specific activations were stronger in dyscalculic children in inferior parietal cortices bilaterally (intraparietal sulcus, supramarginal gyrus, extending to left angular gyrus). Interestingly, fMRI signal strengths reflected a group x task interaction: relative to baseline, controls produced significant deactivations in (intra)parietal regions bilaterally in response to number but not spatial processing, while the opposite pattern emerged in dyscalculics. Moreover, beta weights in response to number processing differed significantly between groups in left - but not right - (intra)parietal regions (becoming even positive in dyscalculic children). CONCLUSION: Overall, findings are suggestive of (a) less consistent neural activity in right (intra)parietal regions upon processing nonsymbolic number magnitudes; and (b) compensatory neural activity in left (intra)parietal regions in developmental dyscalculia.(VLID)218888
EWV-FRM - Emissionsarme Wirtschaftsverkehre in FrankfurtRheinMain : E-Lieferzonen
Abschlussbericht des Forschungsprojekts über emissionsarme Wirtschaftsverkehre in der Metropolregion Frankfurt/Rhein-Main
Different metabolic responses during incremental exercise assessed by localized 31P MRS in sprint and endurance athletes and untrained individuals
Until recently, assessment of muscle metabolism was only possible by invasive sampling. 31P magnetic resonance spectroscopy ( 31P MRS) offers a way to study muscle metabolism non-invasively. The aim of the present study was to use spatially-resolved 31P MRS to assess the metabolism of the quadriceps muscle in sprint-trained, endurance-trained and untrained individuals during exercise and recovery. 5 sprint-trained (STA), 5 endurance-trained (ETA) and 7 untrained individuals (UTI) completed one unlocalized 31P MRS session to measure phosphocreatine (PCr) recovery, and a second session in which spatially-resolved 31P MR spectra were obtained. PCr recovery time constant (τ) was significantly longer in STA (50±17 s) and UTI (41±9 s) than in ETA (30±4 s), (P\u3c0.05). PCr changes during exercise differed between the groups, but were uniform across the different components of the quadriceps within each group. pH during recovery was higher for the ETA than for the UTI (P\u3c0.05) and also higher than for the STA (P\u3c0.01). Muscle volume was greater in STA than in UTI (P\u3c0.05) but not different from ETA. Dynamic 31P MRS revealed considerable differences among endurance and sprint athletes and untrained people. This non-invasive method offers a way to quantify differences between individual muscles and muscle components in athletes compared to untrained individuals. 2013 Georg Thieme Verlag KG Stuttgart.New York
Cardiac magnetic resonance T2 relaxometry in acute myocarditis correlations with myocardial function and cardiac biomarkers
Cardiac Imaging Using Clinical 1.5 T MRI Scanners in a Murine Ischemia/Reperfusion Model
To perform cardiac imaging in mice without having to invest in expensive dedicated equipment, we adapted a clinical 1.5 Tesla (T) magnetic resonance imaging (MRI) scanner for use in a murine ischemia/reperfusion model. Phase-sensitive inversion recovery (PSIR) sequence facilitated the determination of infarct sizes in vivo by late gadolinium enhancement. Results were compared to histological infarct areas in mice after ischemia/reperfusion procedure with a good correlation (r = 0.807, P < .001). In addition, fractional area change (FAC) was assessed with single slice cine MRI and was matched to infarct size (r = −0.837) and fractional shortening (FS) measured with echocardiography (r = 0.860); both P < .001. Here, we demonstrate the use of clinical 1.5 MRI scanners as a feasible method for basic phenotyping in mice. These widely available scanners are capable of investigating in vivo infarct dimensions as well as assessment of cardiac functional parameters in mice with reasonable throughput
Comparison of wall thickening and ejection fraction by cardiovascular magnetic resonance and echocardiography in acute myocardial infarction
<p>Abstract</p> <p>Objectives</p> <p>The purpose of this study was to compare cardiovascular magnetic resonance (CMR) and echocardiography (echo) in patients treated with primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) with emphasis on the analysis of left ventricular function and left ventricular wall motion characteristics.</p> <p>Methods</p> <p>We performed CMR and echo in 52 patients with first AMI shortly after primary angioplasty and four months thereafter. CMR included cine-MR and T1-weighted first-pass and late-gadolinium enhancement (LGE) sequences. Global ejection fraction (EF<sub>CMR</sub>, %) and regional left ventricular function (systolic wall thickening %, [SWT]) were determined from cine-MR images. In echo the global left ventricular function (EF<sub>echo</sub>, %) and regional wall motion abnormalities were determined. A segment in echo was scored as "infarcted" if it was visually > 50% hypokinetic.</p> <p>Results</p> <p>EF<sub>echo </sub>revealed a poor significant agreement with EF<sub>CMR </sub>at baseline (r: 0.326; p < 0.01) but higher correlation at follow-up (r: 0.479; p < 0.001). The number of infarcted segments in echocardiography correlated best with the number of segments which showed systolic wall thickening < 30% (r: 0.498; p < 0.001) at baseline and (r: 0.474; p < 0.001) at follow-up. Improvement of EF was detected in both CMR and echocardiography increasing from 44.2 ± 11.6% to 49.2 ± 11% (p < 0.001) by CMR and from 51.2 ± 8.1% to 54.5 ± 8.3% (p < 0.001) by echocardiography.</p> <p>Conclusion</p> <p>Wall motion and EF by CMR and echocardiography correlate poorly in the acute stage of myocardial infarction. Correlation improves after four months. Systolic wall thickening by CMR < 30% indicates an infarcted segment with influence on the left ventricular function.</p
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