68 research outputs found

    As-built design specification for the digital derivation of daily and monthly data bases from synoptic observations of temperature and precipitation for the People's Republic of China

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    A data base of synoptic meteorological information was compiled for the People's Republic of China, as an integral part of the Large Area Crop Inventory Experiment. A system description is provided, including hardware and software specifications, computation algorithms and an evaluation of output validity. Operations are also outlined, with emphasis placed on least squares interpolation

    Characterizing Acupuncture Stimuli Using Brain Imaging with fMRI - A Systematic Review and Meta-Analysis of the Literature

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    Background The mechanisms of action underlying acupuncture, including acupuncture point specificity, are not well understood. In the previous decade, an increasing number of studies have applied fMRI to investigate brain response to acupuncture stimulation. Our aim was to provide a systematic overview of acupuncture fMRI research considering the following aspects: 1) differences between verum and sham acupuncture, 2) differences due to various methods of acupuncture manipulation, 3) differences between patients and healthy volunteers, 4) differences between different acupuncture points. Methodology/Principal Findings We systematically searched English, Chinese, Korean and Japanese databases for literature published from the earliest available up until September 2009, without any language restrictions. We included all studies using fMRI to investigate the effect of acupuncture on the human brain (at least one group that received needle-based acupuncture). 779 papers were identified, 149 met the inclusion criteria for the descriptive analysis, and 34 were eligible for the meta-analyses. From a descriptive perspective, multiple studies reported that acupuncture modulates activity within specific brain areas, including somatosensory cortices, limbic system, basal ganglia, brain stem, and cerebellum. Meta-analyses for verum acupuncture stimuli confirmed brain activity within many of the regions mentioned above. Differences between verum and sham acupuncture were noted in brain response in middle cingulate, while some heterogeneity was noted for other regions depending on how such meta-analyses were performed, such as sensorimotor cortices, limbic regions, and cerebellum. Conclusions Brain response to acupuncture stimuli encompasses a broad network of regions consistent with not just somatosensory, but also affective and cognitive processing. While the results were heterogeneous, from a descriptive perspective most studies suggest that acupuncture can modulate the activity within specific brain areas, and the evidence based on meta-analyses confirmed some of these results. More high quality studies with more transparent methodology are needed to improve the consistency amongst different studies

    A Visual One-Time Password Authentication Scheme Using Mobile Devices

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    16th International Conference, ICICS 2014, Hong Kong, China, December 16-17, 2014The use of passwords for user authentication has become ubiquitous in our everyday lives. However, password theft is becoming a common occurrence due to a variety of security problems associated with passwords. As such, many organizations are moving towards adopting alternative solutions like one-time passwords, which are only valid for a single session. Nevertheless, various one-time password schemes also suffer from a number of drawbacks in terms of their method of generation or delivery. This paper presents the design of a challenge-response visual one-time password authentication scheme that is to be used in conjunction with the camera on a mobile device. The main purpose of the proposed scheme is to be able to send a challenge over a public channel for a user to obtain a session key, while safeguarding the user’s long-term secret key. In this paper, we present the authentication protocol, the various design considerations and the advantages provided by the scheme.Department of Computin

    Ethyl cellulose, cellulose acetate and carboxymethyl cellulose microstructures prepared using electrohydrodynamics and green solvents

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    Cellulose derivatives are an attractive sustainable material used frequently in biomaterials, however their solubility in safe, green solvents is not widely exploited. In this work three cellulose derivatives; ethyl cellulose, cellulose acetate and carboxymethyl cellulose were subjected to electrohydrodynamic processing. All were processed with safe, environmentally friendly solvents; ethanol, acetone and water. Ethyl cellulose was electrospun and an interesting transitional region was identified. The morphological changes from particles with tails to thick fibres were charted from 17 to 25 wt% solutions. The concentration and solvent composition of cellulose acetate (CA) solutions were then changed; increasing the concentration also increased fibre size. At 10 wt% CA, with acetone only, fibres with heavy beading were produced. In an attempt to incorporate water in the binary solvent system to reduce the acetone content, 80:20 acetone/water solvent system was used. It was noted that for the same concentration of CA (10 wt%), the beading was reduced. Finally, carboxymethyl cellulose was electrospun with poly(ethylene oxide), with the molecular weight and polymer compositions changed and the morphology observed

    金属氧化物纳米材料的设计与合成策略

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    Neurometabolic Improvement in Parkinson\u27s Disease After Stereotactic Functional Neurosurgery by Follow-Up MR Spectroscopy

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    PURPOSE - To investigate neurometabolism from the brain destructive lesions and striatal putamen-pallidus regions to the clinically worst side in patients with Parkinson\u27s disease after stereotactic functional neurosurgery. METHODS - Using proton magnetic resonance spectroscopy (1^1H MRS), fifteen patients (7 males and 8 females; mean age 56.5 years; age range 43-67 years) with Parkinson\u27s disease (PD) were studied to measure N-acetylaspartate (NAA), creatine (Cr), choline-containing compounds (Cho) and lactate (Lac) levels on the neurosurgical lesions of thalamus, globus pallidus and striatal putamen-pallidus regions in a brain. RESULTS - Brain destructive lesion and striatal putamen-pallidus region in PD compared with controls were highly and significantly related to NAA/Cho ratios reduction, respectively (P =0.002, P =0.04), but showed no difference from the same regions of PD prior to neurosergery (P =0.06, P =0.77). Increased lactate peaks at 1.3 ppm were present in all the cerebral lesions, and these resonances were confirmed at a long TE =136 ms, indicating that these signals distinguished from lipids. CONCLUSIONS - Our results suggest that NAA/Cho ratios may provide as a neurometabolite marker for neurochemical changes in brain surgical lesion, and the ratios might be related to functional change of neuropathophysiological status in the striatal putamen-pallidus region of PD. Increase of lactate signals, being remarkable in surgical lesions, could be consistent with a common consequence of surgical necrosis. Therefore, MR spectroscopy could be a sensitive diagnostic tool in monitoring neurometabolic changes in PD with neurosurgical treatment
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