Showing papers by "Hong Zhang published in 2007"
TL;DR: In this article, the effect of overexpression of Hsp40 members Ydj1, Sis1, and Apj1 and also Hsp70 co-chaperones Cpr7, Cns1, Sti1 and Fes1 was investigated.
58 citations
01 Jan 2007
TL;DR: The results suggest that Ydj1 inhibits Ure2 fibril formation by binding to the native state of Ure 2, thus delaying the onset of oligomerization.
Abstract: Jun-Mei Zhou and Sarah PerrettPamela J. E. Rowling, Laura S. Itzhaki,Zhang, Harriet M. Loovers, Gary W. Jones, Hui-Yong Lian, Hong Zhang, Zai-Rong€ Inhibits Formation of Amyloid-like FibrilsState of the Yeast Prion Protein Ure2 and Hsp40 Interacts Directly with the NativeProtein Structure and Folding:
56 citations
TL;DR: It is demonstrated that the Caenorhabditis elegans CBFbeta homolog, bro-1, is essential for the proliferation, differentiation and specification of a row of stem cell-like lineages, called seam cells, and that the transcriptional repression activity of the RNT-1/BRO-1 complex regulates the G1 to S cell cycle progression during seam cell division.
35 citations
TL;DR: It is demonstrated that fli-1 plays an important role in regulating the actin-dependent events during C. elegans development and in specifying asymmetric cell division and in establishing anterior–posterior polarity in the zygote.
Abstract: Flightless I (Fli I) is an evolutionarily conserved member of the gelsolin family, containing actin-binding and severing activity in vitro. The physiological function of Fli I during animal development remains largely undefined. In this study, we reveal a key role of the Caenorhabditis elegans Fli I homolog, fli-1, in specifying asymmetric cell division and in establishing anterior–posterior polarity in the zygote. The fli-1 gene also regulates the cytokinesis of somatic cells and the development of germline and interacts with the phosphoinositol-signaling pathway in the regulation of ovulation. The fli-1 reporter gene shows that the localization of FLI-1 coincides with actin-rich regions and that the actin cytoskeleton is impaired in many tissues in the fli-1 mutants. Furthermore, the function of fli-1 in C. elegans can be functionally substituted by the Drosophila Fli I. Our studies demonstrate that fli-1 plays an important role in regulating the actin-dependent events during C. elegans development.
32 citations
TL;DR: These studies unravel a physiological function of NFY in establishing the spatially restricted expression pattern of egl-5, and show that the NFY complex interacts with the MES-2/MES-6 PcG complex in Hox gene regulation.
29 citations
TL;DR: It is demonstrated that the PcG-like genes in Caenorhabditis elegans, sop-2 and sor-3, regulate the formation of dopaminergic and serotonergic neurons and several other neuronal properties.
Abstract: The molecular mechanisms underlying the formation of neurons with defined neurotransmitters are not well understood. In this study, we demonstrate that the PcG-like genes in Caenorhabditis elegans, sop-2 and sor-3, regulate the formation of dopaminergic and serotonergic neurons and several other neuronal properties. sor-3 encodes a novel protein containing an MBT repeat, a domain that contains histone-binding activity and is present in PcG proteins SCM and Sfmbt in other organisms. We further show that mutations in sor-3 lead to ectopic expression of Hox genes and cause homeotic transformations. Specification of certain neuronal identities by these PcG-like genes appears to involve regulation of non-Hox gene targets. Our studies revealed that the PcG-like genes are crucial for coordinately regulating the expression of discrete aspects of neuronal identities in C. elegans.
16 citations
23 Jul 2007
TL;DR: The proposed method for unsupervised change detection with multi-temporal single- channel single-polarization RADARSAT-1 SAR images deals well with change detection in water area and is based on four main steps.
Abstract: In the present paper, according to data analysis, the problem of change detection has been addressed with unsupervised change detection with multi-temporal single- channel single-polarization RADARSAT-1 SAR images. Method proposed in this paper is based on four main steps: (1) Data preprocessing. SAR images are rectified and calibrated to Gauss-Kruger projection firstly. Moreover they are co-registered to ensure the condition of good accuracy of change detection. (2) Change detection. The window log-ratio approach is adopted to compare multi-temporal SAR data, because of the multiplicative speckle in the images. Then a proper window is selected to average pixels from the two SAR data in log-ratio process instead of pixel by pixel. (3) Selection of optimal threshold value. Minimum error threshold is applied to find the optimal threshold. (4) Change detection map can be obtained by segmentation of window log-ratio image. Experiments show the approach deal well with change detection in water area.
9 citations
23 Jul 2007
TL;DR: This paper presents a robust forest height extraction technique based on reliable phase estimation that can be attained with the reliable ground phase and canopy phase using three-stage inversion process and ESPRIT technique, respectively.
Abstract: Recently, many researches have demonstrated that polarimetric SAR interferometry is the most promising technique for forest parameter extraction. In this paper, we present a robust forest height extraction technique based on reliable phase estimation. The more accurate interferometric phase estimation can be attained with the reliable ground phase and canopy phase using three-stage inversion process and ESPRIT technique, respectively. We show the validity of the method by applying it to L-band simulated polarimetric and interferometric SAR data. The experimental results are also provided to give the availability of this method.
3 citations
TL;DR: In this paper, the authors used IR and 13C-NMR spectroscopy for elucidating the chemical structure of the Gelidium amansii agar fractionation.
Abstract: Studies on Gelidium amansii agar fractionations were carried out in this paper. Gelidium amansii agar was fractionated on DEAE-Cellulose, and four fractions were obtained sequentially. The fractions were analyzed on physical and chemical properties, and IR and 13C-NMR spectroscopy applied for elucidating the chemical structure. Among the four fractions obtained, water fraction measured up to the standard of low EEO agarose. The sulfate content, ash content, electroendosmosis and gel strength (1%) of water fraction were 0.16%, 0.34%, 0.12 and 1 130g/cm2 respectively, similar to those of the Sigma products.
3 citations
01 Jan 2007
TL;DR: In this article, the authors identify and clone the corresponding C. elegans orthologs of the components of the heterotrimeric transcription factor NFY, nfya-1, nfyb-1 and nfyc-1.
Abstract: The C. elegans Hox gene egl-5 (ortholog of Drosophila Abdominal-B) is expressed in multiple tissues in the tail region and is involved in tail patterning. In this study, we identify and clone the corresponding C. elegans orthologs of the components of the heterotrimeric transcription factor NFY, nfya-1, nfyb-1 and nfyc-1 and demonstrate that mutations in these components result in the ectopic expression of egl-5 outside of its normal expression domains. The NFYA-1 protein forms a complex with NFYB-1 and NFYC-1, specifically recognizing the CCAAT box. Mutating a CCAAT box in the proximal promoter of egl-5 also leads to the derepression of egl-5, suggesting a direct role for the NFY complex in the regulation of egl-5. In addition, we show that the NFY complex interacts with the MES-2/MES-6 PcG complex in Hox gene regulation. Thus, our studies unravel a physiological function of NFY in establishing the spatially restricted expression pattern of egl-5.
2 citations
23 Jul 2007
TL;DR: A wavelet based automatic targets detection method for high resolution airborne SAR data is described in this article to receive faster and more accuracy detection and it shows that the algorithm can effectively reduce false alarms caused by speckles.
Abstract: A wavelet based automatic targets detection method for high resolution airborne SAR data is described in this article to receive faster and more accuracy detection. This method is based on the assumption that man-made objects are easily detectable at low resolution because their scattering is more persistent than that of natural objects. The algorithm involves an improved wavelet soft threshold filter (IWSTF) and a wavelet based RCCFAR detector. In order to retain the target feature, the wavelet soft threshold filter is improved by the strategy used in the enhanced Lee filter. Instead of using a global threshold, we adopted an adaptive threshold calculated according to the detail coefficients in each scale. To accelerate the RCCFAR detector, two RCCFAR detectors are used. One is first applied to the approximate coefficients to make a coarse detection. The other one is applied to the filtered images in those regions which are regarded as candidate targets. Performance of the algorithm is assessed by some high resolution airborne SAR image and it shows that the algorithm can effectively reduce false alarms caused by speckles.
23 Jul 2007
TL;DR: The algorithm is performed to investigate the subsidence of CangZhou City, Hebei province (China) during the time of 1993-1997 by using 9 scenes of ERS SAR data, and results show serious subsidence in the region.
Abstract: This paper aims at ground surface deformation retrieval in wide areas including urban and suburb areas based on multi-baseline DInSAR algorithm proposed by Mora. Several progresses are made in order to extract good results. Firstly, a new complex network is presented to restrain noise influence on delaunay triangular network. Secondly, Based on a model coherence function, linear deformation velocity increments and height error increments between neighboring high coherent points (HCPs) are resolved. In order to integrate increments in network, least squares adjustment method and error controlling method are used to obtain stable parameters estimation. At last, by Combining complex and delaunay networks, wide areas deformation is investigated, from center urban areas to suburb areas. The algorithm is performed to investigate the subsidence of CangZhou City, Hebei province (China) during the time of 1993-1997 by using 9 scenes of ERS SAR data. The experiment results show serious subsidence in the region and are validated by leveling data and groundwater wells data.
23 Jul 2007
TL;DR: The organization and the modules of this system are described and the results from CAESAR-XInSAR are also processed in the end, currently at the stage of the development from scientific platform to operational system.
Abstract: In order to meet the need of the development in interferometric SAR, especially the development of Permanent Scatterers InSAR(PS-InSAR) in these years, we develop a new software called CAESAR-XInSAR at the Remote-Sensing Satellite Ground Station, CAS. Both conventional InSAR and PS- InSAR are considered in this system. It supports the interferometric processing from SAR SLC data to end products of DEM or surface deformation map. It is organized in different modules and developed in Visual C++ 6.0 environment on PC under windows operating system. It is currently at the stage of the development from scientific platform to operational system. In this paper, the organization and the modules of this system are described and the results from CAESAR-XInSAR are also processed in the end.