57 research outputs found
Research into Satisfaction with Industrial Heritage Renewal Based on the SEM-IPA Model: A Case Study of the Dongguan Jianyuzhou Park
The objective of this study was to establish a satisfaction evaluation model of industrial heritage renewal by evaluating the performance of old industrial buildings after renewal, then judging the adaptability and accuracy of the transformation strategy and putting forward targeted improvement suggestions. The data were collected through a questionnaire survey and analyzed by the statistical package for social science (SPSS) software using a structural equation model (SEM) and importance–performance analysis (IPA). The results show that (1) history, culture, and placeness have the largest average satisfaction and a positive and significant impact on overall satisfaction; (2) the building regeneration effect has a significant impact on overall satisfaction; and (3) social influence, external environmental perception, and economic benefits have no significant effect on overall satisfaction, indicating the need to strengthen public participation for further research into environmental creation, market-based operation, and land conservation. This case study reflects the distinctive features of internationalization and localization, and provides an indication of local practice in China for world urban renewal and architectural heritage theories
Synchronous multimode ultrasound for assessing right-to-left shunt: a prospective clinical study
BackgroundRight-to-left shunt (RLS) is associated with several conditions and causes morbidity. In this study, we aimed to evaluate the effectiveness of synchronous multimode ultrasonography in detecting RLS.MethodsWe prospectively enrolled 423 patients with high clinical suspicion of RLS and divided them into the contrast transcranial Doppler (cTCD) group and synchronous multimode ultrasound group, in which both cTCD and contrast transthoracic echocardiography (cTTE) were performed during the same process of contrast-enhanced ultrasound imaging. The simultaneous test results were compared with those of cTCD alone.ResultsThe positive rates of grade II (22.0%:10.0%) and III (12.7%:10.8%) shunts and the total positive rate (82.1748%) in the synchronous multimode ultrasound group were higher than those in the cTCD alone group. Among patients with RLS grade I in the synchronous multimode ultrasound group, 23 had RLS grade I in cTCD but grade 0 in synchronous cTTE, whereas four had grade I in cTCD but grade 0 in synchronous cTTE. Among patients with RLS grade II in the synchronous multimode ultrasound group, 28 had RLS grade I in cTCD but grade II in synchronous cTTE. Among patients with RLS grade III in the synchronous multimode ultrasound group, four had RLS grade I in cTCD but grade III in synchronous cTTE. Synchronous multimode ultrasound had a sensitivity of 87.5% and specificity of 60.6% in the patent foramen ovale (PFO) diagnosis. Binary logistic regression analyses showed that age (odds ratio [OR] = 1.041) and risk of paradoxical embolism score ≥ 7 (OR = 7.798) were risk factors for stroke recurrence, whereas antiplatelets (OR = 0.590) and PFO closure with antiplatelets (OR = 0.109) were protective factors.ConclusionSynchronous multimodal ultrasound significantly improves the detection rate and test efficiency, quantifies RLS more accurately, and reduces testing risks and medical costs. We conclude that synchronous multimodal ultrasound has significant potential for clinical applications
Rolling-Circle Amplification of Centromeric Helitrons in Plant Genomes
The unusual eukaryotic Helitron transposons can readily capture host sequences and are, thus, evolutionarily important. They are presumed to amplify by rolling-circle replication (RCR) because some elements encode predicted proteins homologous to RCR prokaryotic transposases. In support of this replication mechanism, it was recently shown that transposition of a bat Helitron generates covalently closed circular intermediates. Another strong prediction is that RCR should generate tandem Helitron concatemers, yet almost all Helitrons identified to date occur as solo elements in the genome. To investigate alternative modes of Helitron organization in present-day genomes, we have applied the novel computational tool HelitronScanner to 27 plant genomes and have uncovered numerous tandem arrays of partially decayed, truncated Helitrons in all of them. Strikingly, most of these Helitron tandem arrays are interspersed with other repeats in centromeres. Many of these arrays have multiple Helitron 5′ ends, but a single 3′ end. The number of repeats in any one array can range from a handful to several hundreds. We propose here an RCR model that conforms to the present Helitron landscape of plant genomes. Our study provides strong evidence that plant Helitrons amplify by RCR and that the tandemly arrayed replication products accumulate mostly in centromeres
Rolling‐circle amplification of centromeric Helitrons
The unusual eukaryotic Helitron transposons can readily capture host sequences and are, thus, evolutionarily important. They are presumed to amplify by rolling-circle replication (RCR) because some elements encode predicted proteins homologous to RCR prokaryotic transposases. In support of this replication mechanism, it was recently shown that transposition of a bat Helitron generates covalently closed circular intermediates. Another strong prediction is that RCR should generate tandem Helitron concatemers, yet almost all Helitrons identified to date occur as solo elements in the genome. To investigate alternative modes of Helitron organization in present-day genomes, we have applied the novel computational tool HelitronScanner to 27 plant genomes and have uncovered numerous tandem arrays of partially decayed, truncated Helitrons in all of them. Strikingly, most of these Helitron tandem arrays are interspersed with other repeats in centromeres. Many of these arrays have multiple Helitron 5′ ends, but a single 3′ end. The number of repeats in any one array can range from a handful to several hundreds. We propose here an RCR model that conforms to the present Helitron landscape of plant genomes. Our study provides strong evidence that plant Helitrons amplify by RCR and that the tandemly arrayed replication products accumulate mostly in centromeres
Dynamic time slot allocation and stream control for MIMO STDMA in ad hoc networks
Abstract Multiple-input multiple-output (MIMO) technologies have been shown to potentially improve the performance of network. Many traditional medium access control (MAC) protocols, such as spatial time division multiple access (STDMA), may not support MIMO technologies directly and not make full use of the feature of MIMO, which may be a limitation in the practical application in ad hoc networks. Therefore, in this paper, we propose a dynamic time slot allocation and stream control for MIMO STDMA (DTSMS) protocol to improve STDMA in performance. Utilizing stream control technology of MIMO and reservation scheme, DTSMS makes improvement on network throughput and avoids the mutual interference of neighbor links. Thus, DTSMS can support both unicast and multicast simultaneously. Moreover, we implement the dynamic time slot allocation scheme in DTSMS to guarantee the transmission efficiency of packets with high cross-layer transmission parameters, such as the packet priority, neighbor node density, or link quality. Utilizing the collected cross-layer information, the proposed scheme allocates time slots for all nodes dynamically according to the changes of network topology and nodes’ transmission parameters. Finally, the effectiveness of the protocol is demonstrated by numerical analysis and simulations. The results show that DTSMS outperforms STDMA in terms of network throughput and delay. Furthermore, compared to our previous TTS-MIMO, DTSMS can decrease the delay of packets with high transmission parameters and improve the quality of service (QoS)
A Point Pattern Chamfer Registration of Optical and SAR Images Based on Mesh Grids
Automatic image registration of optical-to-Synthetic aperture radar (SAR) images is difficult because of the inconsistency of radiometric and geometric properties between the optical image and the SAR image. The intensity-based methods may require many calculations and be ineffective when there are geometric distortions between these two images. The feature-based methods have high requirements on features, and there are certain challenges in feature extraction and matching. A new automatic optical-to-SAR image registration framework is proposed in this paper. First, modified holistically nested edge detection is employed to detect the main contours in both the optical and SAR images. Second, a mesh grid strategy is presented to perform a coarse-to-fine registration. The coarse registration calculates the feature matching and summarizes the preliminary results for the fine registration process. Finally, moving direct linear transformation is introduced to perform a homography warp to alleviate parallax. The experimental results show the effectiveness and accuracy of our proposed method
Helitron Scanner Uncovers a Large Overlooked Cache of Helitron Transposons in Many Plant Genomes
Transposons make up the bulk of eukaryotic genomes, but are difficult to annotate because they evolve rapidly. Most of the unannotated portion of sequenced genomes is probably made up of various divergent transposons that have yet to be categorized. Helitrons are unusual rolling circle eukaryotic transposons that often capture gene sequences, making them of considerable evolutionary importance. Unlike other DNA transposons, Helitrons do not end in inverted repeats or create target site duplications, so they are particularly challenging to identify. Here we present HelitronScanner, a two-layered local combinational variable (LCV) tool for generalized Helitron identification that represents a major improvement over previous identification programs based on DNA sequence or structure. HelitronScanner identified 64,654 Helitrons from a wide range of plant genomes in a highly automated way. We tested HelitronScanner\u27s predictive ability in maize, a species with highly heterogeneous Helitron elements. LCV scores for the 5? and 3? termini of the predicted Helitrons provide a primary confidence level and element copy number provides a secondary one. Newly identified Helitrons were validated by PCR assays or by in silico comparative analysis of insertion site polymorphism among multiple accessions. Many new Helitrons were identified in model species, such as maize, rice, and Arabidopsis, and in a variety of organisms where Helitrons had not been reported previously to our knowledge, leading to a major upward reassessment of their abundance in plant genomes. HelitronScanner promises to be a valuable tool in future comparative and evolutionary studies of this major transposon superfamily
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