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A new different method has been developed for solving one-dimensional parabolic differential equations in this paper. Here, the standard backward Euler difference scheme was improved by the clustering algorithm. The method is illustrated by numerical examples. It not only reduces computing time remarkably, but also shows better performance in data storage and at the same time is more stable than the standard backward Euler difference scheme.

The paralogous maize (Zea mays) LBD (Lateral Organ Boundaries Domain) genes rtcs (rootless concerning crown and seminal roots) and rtcl (rtcs-like) emerged from an ancient whole-genome duplication. RTCS is a key regulator of crown root initiation. The diversity of expression, molecular interaction and phenotype of rtcs and rtcl were investigated. The rtcs and rtcl genes display highly correlated spatio-temporal expression patterns in roots, despite the significantly higher expression of rtcs. Both RTCS and RTCL proteins bind to LBD downstream promoters and act as transcription factors. In line with its auxin inducibility and binding to auxin response elements of rtcs and rtcl promoters, ARF34 (AUXIN RESPONSE FACTOR 34) acts as transcriptional activator. Yeast two-hybrid screening combined with bimolecular fluorescence complementation (BiFC) experiments revealed conserved and unique interaction partners of RTCS and RTCL. The rtcl mutation leads to defective shoot-borne root elongation early in development. Cooperative action of RTCS and RTCL during shoot-borne root formation was demonstrated by rtcs-dependent repression of rtcl transcription in coleoptilar nodes. Although RTCS is instrumental in shoot-borne root initiation, RTCL controls shoot-borne root elongation early in development. Their conserved role in auxin signaling, but diverse function in shoot-borne root formation, is underscored by their conserved and unique interaction partners.

In this paper, we proposed a new method for the numerical solutions of a two-dimensional Poisson equation, where we used k-modes clustering algorithm to improve the standard five-point difference scheme. Numerical experiments have shown that the five-point difference method based on k-modes cluster is effective and efficient. The proposed new method not only reduces computing time remarkably, but also shows better performance in data storage and stability than the standard five-point difference scheme.

Salinity and drought severely affect both plant growth and productivity, making the isolation and characterization of salinity- or drought-inducible promoters suitable for genetic improvement of crop resistance highly desirable. In this study, a 1468-bp sequence upstream of the translation initiation codon ATG of the promoter for ZmGAPP (maize Type-II H+-pyrophosphatase gene) was cloned. Nine 5´ deletion fragments (D1-D9) of different lengths of the ZmGAPP promoter were fused with the GUS reporter and translocated into tobacco. The deletion analysis showed that fragments D1-D8 responded well to NaCl and PEG stresses, whereas fragment D9 and CaMV 35S did not. The D8 segment (219 bp; -219 to -1 bp) exhibited the highest promoter activity of all tissues, with the exception of petals among the D1-D9 transgenic tobacco, which corresponds to about 10% and 25% of CaMV 35S under normal and NaCl or PEG stress conditions, respectively. As such, the D8 segment may confer strong gene expression in a salinity and osmotic stress inducible manner. A 71-bp segment (-219 to -148 bp) was considered as the key region regulating ZmGAPP response to NaCl or PEG stress, as transient transformation assays demonstrated that the 71-bp sequence was sufficient for the salinity or osmotic stress response. These results enhance our understanding of the molecular mechanisms regulating ZmGAPP expression, and that the D8 promoter would be an ideal candidate for moderating expression of drought and salinity response genes in transgenic plants.

Rootless concerning crown and seminal roots(Rtcs) encodes a LATERAL ORGAN BOUNDARIES domain (LBD) protein that regulates shoot-borne root initiation in maize (Zea maysL.). GREEN FLUORESCENT PROTEIN (GFP)-fusions revealed RTCS localization in the nucleus while its paralogue RTCS-LIKE (RTCL) was detected in the nucleus and cytoplasm probably owing to an amino acid exchange in a nuclear localization signal. Moreover, enzyme-linked immunosorbent assay (ELISA) experiments demonstrated that RTCS primarily binds toLBDDNA motifs. RTCS binding to anLBDmotif in the promoter of the auxin response factor (ARF)ZmArf34and reciprocally, reciprocal ZmARF34 binding to an auxin responsive element motif in the promoter ofRtcswas shown by electrophoretic mobility shift assay experiments. In addition, comparative qRT-PCR of wild-type versusrtcscoleoptilar nodes suggested RTCS-dependent activation ofZmArf34expression. Consistently, luciferase reporter assays illustrated the capacity of RTCS, RTCL and ZmARF34 to activate downstream gene expression. Finally, RTCL homo- and RTCS/RTCL hetero-interaction were demonstrated in yeast-two-hybrid and bimolecular fluorescence complementation experiments, suggesting a role of these complexes in downstream gene regulation. In summary, the data provide novel insights into the molecular interactions resulting in crown root initiation in maize.

Maize rough dwarf disease (MRDD) is a viral disease and causes great yield loss. To better understand the effects of MRDD on plant growth and metabolism, comparative proteomic analysis of leaves from virus-infected and normal plants was performed. In order to eliminate the interference of Ribulose-1, 5-bisphosphate carboxylase with low-abundance proteins, total proteins were pre-fractionated by 15% PEG and the proteins from supernatant and precipitated fractions were analyzed by 2-DE, subsequently. Out of approximately 1200 protein spots detected, less than 2% of the spots on the gels were overlapping between the fractions of precipitation and supernatant. We identified 91 differentially accumulated proteins that belong to multiple metabolic/biochemical pathways in plants. Further analysis of these identified proteins indicated that MRDD resulted in dramatic changes in the fundamental metabolism, including glycolysis and starch metabolism, and eventually the significant differences in morphology and development between virus-infected and normal plants. Moreover, MRDD occurrence increased the demands for G-proteins, antioxidant enzymes, lipoxygenases and UDP-glucosyltransferase BX9, which may play important roles in response of plant against virus infection. The results also suggested that MRDD is a complicated disease controlled by multigene participating in different pathways.

While applying attribute based access control in dynamic open multi-domain environments, an important critical problem is how to make these domains know each other about the semantics of attributes defined by them. Towards this problem, a novel method of attribute matching is proposed in this paper. This matching is based on other domains’ knowledges of the specific concept relationship. The knowledge involves five different concept relationships. Compared with the numerical similarity between two concepts, these concept relationships are more applicable in access control. In addition, the proposed method does not need the overall information of ontologies to which the matched concepts belong. For this, examples are given to illustrate applications of the method.

Concept alignment, namely how to make different domains know each other about the semantics of concepts defined by them, is one of the key issues of applying attribute based access control in dynamic open multi-domain environment. In this paper, a novel approach is proposed for building up a concept alignment framework based on other domains’ knowledge about specific concept relationship. The knowledge comprises five different definite concept relationships which are represented by five logical formulae respectively. Compared with the numerical similarity and those related approaches, the knowledge is more suitable for depicting concept relationship, while the proposed approach is more adapted in access control. Finally, a trust degree model is introduced into the framework in order to improve the quality of concept alignment results, and how to use and manage the trust degree is discussed.

In the traditional history-based access control model, the policy is designed regarding only one subject. This policy is vulnerable, because if multi-subjects who have common interests collaborate, the access control may be bypassed. In addition, designing policy for multi-subjects' access is indispensable for many online applications. Towards this problem, a temporal access control based on multi-subjects is proposed in this paper. The main idea is to make decision of access according to active multi-subjects' history executions. A policy language is introduced and its syntax and semantics are defined formally. Finally, a policy verification algorithm is given and an example is used to illustrate it.

We evaluated the long-term efficacy of the combination of transcatheter arterial chemoembolization (TACE) using cisplatin-lipiodol suspension, transultrasonic portal vein chemoembolization (SPVE), radiofrequency ablation (RF), percutaneous ethanol injection (PEI) for treatment of advanced small hepatocellular carcinoma (HCC).A total of three hundred and eighteen patients with HCC were enrolled in this study. According to the blood supply characteristics to the tumor, individual combined therapy models were adopted: one hundred and fifty-nine patients with HCC less than 5 cm were treated with a combination of RF and PEI (RF/PEI group) and one hundred and one patients with HCC greater than 5cm were treated with a combination of TACE, RF and PEI (TACE/RF/PEI group). One hundred and eleven HCC nodules confirmed to be hypervascular by color Doppler flow imaging were treated with a combination of TACE, RF, SPVE and PEI (TACE/ RF/SPVE/PEI group).The combination treatment of RF and PEI (RF/PEI group), the TACE/RF/PEI group, TACE/ RF/SPVE/PEI group, the 1-year survival rates and the 3-year survival rates were 97.3% and 82.4%; 73.5% and 44.9%; 74.1% and 37.9%, respectively; The vanishing rate of blood flow around and within the tumor, the tumor size decrease rate, AFP transformed to negative rate, were significantly raised compared to those in the TACE treatment only group.The individual combined therapy models combination of TACE, PEI, SPVE, RF appears to prolong survival, compared with one treatment alone (TACE). This combination therapy method is an effective way for treating HCC, and color Doppler can provide important information to verify the therapeutic effects.

Phosphorus (P) deficiency is a major limitation for plant growth and development. Plants can respond defensively to this stress, modifying their metabolic pathways and root morphology, and this involves changes in their gene expression. To better understand the low P adaptive mechanism of crops, we conducted the comparative proteome analysis for proteins isolated from maize roots treated with 1000 microM (control) or 5 microM KH2PO4 for 17 days. The results showed that approximately 20% of detected proteins on 2-DE gels were increased or decreased by two-fold or more under phosphate (Pi) stress. We identified 106 differentially expressed proteins by MALDI-TOF MS. Analysis of these P starvation responsive proteins suggested that they were involved in phytohormone biosynthesis, carbon and energy metabolisms, protein synthesis and fate, signal transduction, cell cycle, cellular organization, defense, secondary metabolism, etc. It could be concluded that they may play important roles in sensing the change of external Pi concentration and regulating complex adaptation activities for Pi deprivation to facilitate P homeostasis. Simultaneously, as a basic platform, the results would also be useful for the further characterization of gene function in plant P nutrition.

Background Phosphorus (P) is an essential macronutrient for all living organisms. Maize (Zea mays) is an important human food, animal feed and energy crop throughout the world, and enormous quantities of phosphate fertilizer are required for maize cultivation. Thus, it is important to improve the efficiency of the use of phosphate fertilizer for maize. Results In this study, we analyzed the maize root response to phosphate starvation and performed a transcriptomic analysis of the 1.0-1.5 cm lateral root primordium zone. In the growth of plants, the root-to-shoot ratio (R/L) was reduced in both low-phosphate (LP) and sufficient-phosphate (SP) solutions, but the ratio (R/L) exhibited by the plants in the LP solution was higher than that of the SP plants. The growth of primary roots was slightly promoted after 6 days of phosphate starvation, whereas the numbers of lateral roots and lateral root primordia were significantly reduced, and these differences were increased when associated with the stress caused by phosphate starvation. Among the results of a transcriptomic analysis of the maize lateral root primordium zone, there were two highlights: 1) auxin signaling participated in the response and the modification of root morphology under low-phosphate conditions, which may occur via local concentration changes due to the biosynthesis and transport of auxin, and LOB domain proteins may be an intermediary between auxin signaling and root morphology; and 2) the observed retardation of lateral root development was the result of co-regulation of DNA replication, transcription, protein synthesis and degradation and cell growth. Conclusions These results indicated that maize roots show a different growth pattern than Arabidopsis under low-phosphate conditions, as the latter species has been observed to halt primary root growth when the root tip comes into contact with low-phosphate media. Moreover, our findings enrich our understanding of plant responses to phosphate deficits and of root morphogenesis in maize.