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Green principles have been increasingly incorporated into planning, design, construction, and maintenance processes in the engineering and construction industry. Along with the growth of the green initiative, going green not only demonstrates corporate social responsibility, but may yield significant economic benefits. This study compares financial performance between green and conventional firms in the engineering and construction industry. A total of 22 sample companies used in this empirical analysis are categorized into two groups—green versus conventional firms—in accordance with Engineering News Record and Newsweek green company lists. Two groups are compared in terms of short-term financial performance, long-term economic value, and market value. The analysis shows that green firms outperform conventional firms on return on equity (17.4 versus 8.2%) and economic value added margin (0.35 versus −1.43%). However, the green strategy has not yet been factored into corporate market value. The fi...

The management of facility construction for hallmark events is critically important for their financial viability. However, little knowledge has been produced regarding the management of this type of construction. Based on the construction program for the Shanghai Expo 2010 and other cases reported in the literature, this paper provides an analysis of the common characteristics of construction for hallmark events, the challenges of financial management due to these characteristics, techniques to address these challenges, and lessons learned from the Expo construction. It is believed that one critical factor that contributes to the success of the Expo construction program is the integration of the financial management and contract management processes, assisted by a specifically designed computer program. The techniques used to integrate the two processes involve (1) mapping the program’s work breakdown structure, cost breakdown structure, and contract breakdown structure; (2) integrating the infor...

Defects in natural killer (NK) cell functions are necessary for tumor immune escape, but their underlying regulatory mechanisms in human cancers remain largely unknown. Here we show, in detailed studies of NK cells in 294 untreated patients with hepatocellular carcinoma (HCC), that accumulation of functional NK cells in HCC tissues could predict improved survival of patients. However, in patients with advanced-stage HCC, NK cells were significantly decreased in number with impaired tumor necrosis factor alpha (TNF-α) and interferon-gamma (IFN-γ) production. High infiltration of peritumoral stroma monocytes/macrophages was positively correlated with impaired functional activities of NK cells in intratumoral areas. Further kinetic experiments revealed that soon after exposure to tumor-derived monocytes, NK cells underwent a rapid, transient activation, but then they became exhausted, and eventually died. The monocytes from HCC tissues, but not from nontumoral liver, strongly express CD48 proteins; and such monocyte-induced NK cell dysfunction was markedly attenuated by blocking CD48 receptor 2B4 on NK cells, but not by blockade of NKG2D and NKp30. Conclusion: These data reveal that human NK cells are regulated by a fine-tuned collaborative action between different types of immune cells, which may reflect a novel immune-escape mechanism by which tumors dynamically regulate their functions at distinct tumor microenvironments. (HEPATOLOGY 2013)

The distributed energy policies and regulations in China have been lagged for a long time, which is seriously blocking further development of distributed energy. The current rule-system has such problems as follows: firstly it lacks a systematically-planed strategies and development blue print, secondly the current rules are all just ideal principles without practical solutions, thirdly the positive preferential policies are absent, and finally the unified standard for the electric power integration is needed. There are four principles be obeyed to improve the rule-system: consideration of everything, balancing of everything, systematic management and consistency with science. Basing on these principles, we should establish a systematic plan, a perfect integration mechanism, a price mechanism and series of stable incentive policies for distributed energy in order to reach the goal.

With the rapid development of computer and Internet technologies, users increasingly demand for more individualistic information. In the era of Internet, it has become an important task for academic libraries of agriculture to construct a suitable information service system and to integrate various resources, so as to enable users to have access to individualistic information system.

This research examines the role and nature of the influential relationship between trust and project success in construction projects by using structural equation modeling (SEM) and a large-scale questionnaire survey. Such a relationship is investigated based on three key components: six antecedents of trust as independent variables (reputation, competence, integrity, communication, reciprocity, and contract), two types of trust as mediating variables (calculative and relative trust), and project success as a dependent variable. The results differentiate and compare the perceptions of trust for both owners and contractors in terms of their priority for antecedents of trust, the influential mechanism that connects trust with project success, and the numerical relationship between calculative trust and relational trust. For both parties, relational trust generates a higher impact on project success than calculative trust, but contractors perceived the relationship between relational trust and calcul...

Over recent years, the issue of corruption in the public construction sector has attracted increasing attention from both practitioners and researchers worldwide. However, limited efforts are available for investigating the underlying factors of corruption in this sector. Thus, this study attempted to bridge this knowledge gap by exploring the underlying factors of corruption in the public construction sector of China. To achieve this goal, a total of 14 structured interviews were first carried out, and a questionnaire survey was then administered to 188 professionals in China. Two iterations of multivariate analysis approaches, namely, stepwise multiple regression analysis and partial least squares structural equation modeling were successively utilized to analyze the collected data. In addition, a case study was also conducted to triangulate the findings obtained from the statistical analysis. The results generated from these three research methods achieve the same conclusion: the most influential underlying factor leading to corruption was immorality, followed by opacity, unfairness, procedural violation, and contractual violation. This study has contributed to the body of knowledge by exploring the properties of corruption in the public construction sector. The findings from this study are also valuable to the construction authorities as they can assist in developing more effective anti-corruption strategies.

Organizational culture is context-specific and it can impact organizational effectiveness in certain mechanism. From Competing Values Framework (CVF) prospective, this study examines the correlations among organizational culture, organizational citizenship behavior (OCB), and organizational effectiveness. Furthermore, this study analyzes the possible mediating role of OCB in the relationship between organizational culture and organizational effectiveness. A questionnaire-based survey was used to measure the related constructs. The results suggest that OCB partially mediates the impact of organizational culture on organizational effectiveness. The results also indicate the feasibility of impact mechanism of organizational culture on effectiveness. The research findings provide the implications for project management literature and practices.

In this paper, an asymmetric permagnet biased axial magnetic bearing has developed. The PM rings can not only produce bias flux, but also provide a large axial force to reduce the burden of axial bearing. As a result, the proposed PBAMB can lower the current, lower the power loss and make an easier control. Firstly, structure and operation principle are introduced. Then, the mathematical models are built based on traditional equivalent magnetic circuit. The analytical and design results are verified by finite element method (FEM). The loss is also analyzed by comparing with usual AMBs and symmetric PBAMB. The result shows the copper loss is reduced to 22% of usual AMBs and 56% of symmetric PBAMB. Finally, the design principle has been introduced in detail. The proposed PBAMB has an important reference value for magnetic bearings applied in the device when the load forces in two axial directions are different.

The emergence of construction megaprojects has become a global phenomenon over the last two decades as a result of rapid urbanization. Program management has been increasingly promoted as a vital approach for ensuring megaproject success through the coordinated management of the dispensed execution of a program at the organizational level. Nevertheless, practicing this method in construction megaprojects is a continual improvement process that requires relevant guidelines and tools. This study proposes an innovative tool to evaluate a structured program organization in conjunction with the fuzzy synthetic evaluation method. Based on determinants of program organization identified from a Delphi survey previously conducted by authors regarding the Shanghai Expo construction, combined with results of further Delphi surveys for the same project, the use of this new evaluation approach in the case project is illustrated step-by-step. With this tool, clients can better utilize the program management app...

Over the last two decades, social network analysis (SNA) approach has gained increasing popularity as an advanced tool in Construction Engineering and Management (CEM) field due to the emerging viewpoint of viewing projects as organizational networks. However, limited studies are available on a systematic review of the use of this tool in CEM field. Therefore, this paper aims to fill this gap by reviewing the SNA papers published in nine selected peer-reviewed journals from 1998 to 2015 to ascertain the state of the art. Based on a three-stage review, 45 papers were identified. It was found that scholars from the United States, the United Kingdom and Australia published the most number of SNA-based papers, which indicated universities (institutions) and scholars from these countries enjoy significant advantage in SNA-based research. The review results provide practical references for future SNA enable applications in CEM research.

Since its publication in 2005, the New Engineering Contract Version 3 (NEC3) [ICE (2013). New Engineering Contract 3] has increasingly been promoted as a relational contracting instrument for establishing mutual trust and for facilitating interorganizational collaboration. However, only a few empirical studies have documented the use of this contract in practice. Therefore, the current research investigates the initiation, execution, benefits, and critical factors in the implementation of NEC3-based relational practices. The lessons learned from this implementation are compared with those derived from the application of the integrated project delivery (IPD) approach in the United States. This study also analyzes the NEC3 Engineering and Construction Contract (ECC) [ICE (2005). NEC3 Engineering and Construction Contract] through a case study of the first pilot project in Hong Kong to adopt this new contract. Study findings not only reinforce the usefulness of well-established relational components ...

MicroRNAs (miRNAs) are 22-nt non-coding RNAs involved in the regulation of cellular gene expression and potential cellular defense against viral infection. Using in silico analyses, we predicted target sites for 22 human miRNAs in the HIV genome. Transfection experiments using synthetic miRNAs showed that five of these miRNAs capably decreased HIV replication. Using one of these five miRNAs, human miR-326 as an example, we demonstrated that the degree of complementarity between the predicted viral sequence and cellular miR-326 correlates, in a Dicer-dependent manner, with the potency of miRNA-mediated restriction of viral replication. Antagomirs to miR-326 that knocked down this cell endogenous miRNA increased HIV-1 replication in cells, suggesting that miR-326 is physiologically functional in moderating HIV-1 replication in human cells.

Earthworms, one of the most important macroinvertebrates in terrestrial ecosystems of temperate zones, exert important influences on soil functions. A laboratory microcosm study was conducted to evaluate the influence of the earthworm Eisenia fetida on wheat straw decomposition and nutrient cycling in an agricultural soil in a reclaimed salinity area of the North China Plain. Each microcosm was simulated by thoroughly mixing wheat straw into the soil and incubated for 120 d with earthworms added at 3 different densities as treatments: control with no earthworms, regular density (RD) with two earthworms, and increased density (ID) with six earthworms. The results showed that there was no depletion of carbon and nitrogen pools in the presence of the earthworms. Basal soil respiration rates and metabolic quotient increased with the increase in earthworm density during the initial and middle part of the incubation period. In contrast, concentrations of microbial biomass carbon and microbial biomass quotient decreased in the presence of earthworms. Earthworm activity stimulated the transfer of microbial biomass carbon to dissolved organic carbon and could lead to a smaller, but more metabolically active microbial biomass. Concentrations of inorganic nitrogen and NO−3-N increased significantly with the increase in earthworm density at the end of the incubation (P < 0.05), resulting in a large pool of inorganic nitrogen available for plant uptake. Cumulative net nitrogen mineralization rates were three times higher in the ID treatment than the RD treatment.

To provide a more reliable and low power consumption rotor support system for a high-speed compressor, a novel and compact magnetic bearing and damping system is proposed. It is composed of a cup-shaped rotor, an axial passive bearing of reluctance type outside the rotor cup, and a passive damper with Halbach magnet array inside the rotor cup, which not only can provide adequate stiffness, but also good damping ability for the rotor. To enhance the load and stability of the system, an analytical model, which can calculate the system stiffness and damping coefficient with significantly less computing time than the finite element method (FEM), is established. The effects of some important structure parameters on the system performance are discussed. Then, an optimal design method is proposed based on the above analysis. At last, an experimental setup has been developed and both static and dynamic performances have been tested. The experimental results show that the proposed system is capable of producing high axial stiffness and effective in suppressing the rotor vibration. The results also verify the validity of the analysis and design method.

In order to understand Preservation effect on Brassica napus by MSOD, different concentrations of poly-aspartic manganese (II), ferrous cysteine, copper glycine are sprayed to Brassica napus, activity changes in SOD and POD and changes of MDA content are inspected. The results showed that for Brassica napus sprayed with MSOD, it makes preservation effect higher and storage period longer.

As the biggest expo site in history, construction of the Shanghai Expo site faced a lot of challenges, including involvement of lots of investors, megaconstruction scale, concurrent construction mode, involvement of more than 40,000 migrant workers, and extremely tight completion deadlines, among others. Consequently, these challenges imposed great obstacles on accomplishing the safety, quality, and environmental goals. Through a case study of the Shanghai Expo construction, this paper paper presents the design and implementation of multicriteria incentives in megaprojects to accomplish the safety, quality, and environmental goals. Both quantitative and qualitative findings were triangulated to demonstrate the outcome of the incentives. Six critical success factors (CSFs) for the incentives, rule design, process orientation, top management support, training and promotion, communication in process, and process learning and improvement are identified and validated through case study data and content analysis. It is believed that the findings of this paper can enhance understanding of multicriteria incentive schemes in general and provide insights in implementing these incentive schemes in future megaprojects, particularly in the People’s Republic of China (PRC).

Background The microenvironment within solid tumors has often been shown to exhibit an acidic extracellular pH. Although the morphologic and functional differences in natural killer (NK) cells of the liver and spleen have been reported previously under physiological conditions, the difference under acidic conditions is still unclear. This study was to investigate the differences in the morphological and functional characteristics between rat liver and spleen NK cells under normal and acidic conditions in vitro. Methods Liver and spleen NK cells were isolated and purified from Sprague-Dawley rats by density gradient centrifugation and the Dynabeads® FlowComp™ Flexi system, and stimulated for 4 days with or without IL-2 or treated with low pH or control for different times. Morphology was examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), cell death and proliferation assays were performed by flow cytometry, IFN-γ production was tested by ELISA, and cytotoxic activity was evaluated by lactate dehydrogenase (LDH) release assay. Results Liver NK cells had significantly higher levels of cytotoxic activity than spleen NK cells under normal and acidic conditions, and the maximum difference was observed at pH 5.6. Further analysis revealed that the cytotoxic activity of NK cells was correlated with morphology, cell death, proliferative activity and IFN-γ production. By TEM, liver NK cells contained a greater number of electron-dense granules per cell at pH 5.6. Moreover, a modest elevation of cell death and reduction of proliferation of liver NK cells occurred within a range of 5.6–7.2. Interestingly, an acidic extracellular pH only marginally, and not significantly, suppressed IFN-γ production by liver NK cells. Conclusions The sharp morphological and functional differences shown by the two types of NK cells in vitro indicate that liver NK cells are unexpectedly resistant to pH shock.

Failure of immune surveillance related to inadequate host antitumor immune responses has been suggested as a possible cause of the high incidence of recurrence and poor overall survival outcome of hepatocellular carcinoma. The stress-induced heat shock proteins (HSPs) are known to act as endogenous "danger signals" that can improve tumor immunogenicity and induce natural killer (NK) cell responses. Exosome is a novel secretory pathway for HSPs. In our experiments, the immune regulatory effect of the HSP-bearing exosomes secreted by human hepatocellular carcinoma cells under stress conditions on NK cells was studied. ELISA results showed that the production of HSP60, HSP70, and HSP90 was up-regulated in both cell lines in a stress-specific manner. After exposure to hepatocellular carcinoma cell-resistant or sensitive anticancer drugs (hereafter referred to as "resistant" or "sensitive" anticancer drug), the membrane microvesicles were actively released by hepatocellular carcinoma cells, differing in their ability to present HSPs on the cell surface, which were characterized as exosomes. Acting as a decoy, the HSP-bearing exosomes efficiently stimulated NK cell cytotoxicity and granzyme B production, up-regulated the expression of inhibitory receptor CD94, and down-regulated the expression of activating receptors CD69, NKG2D, and NKp44. Notably, resistant anticancer drugs enhanced exosome release and generated more exosome-carried HSPs, which augmented the activation of the cytotoxic response. In summary, our findings demonstrated that exosomes derived from resistant anticancer drug-treated HepG2 cells conferred superior immunogenicity in inducing HSP-specific NK cell responses, which provided a clue for finding an efficient vaccine for hepatocellular carcinoma immunotherapy.

There is in lack of trust in construction projects. It is criticized by many scholars. Trust has the function of decreasing transaction cost and improving project performance. The characteristics of the trustee have important function on occurrence of trust. More specifically, the trustee’s reputation, competence and promise keeping contribute to occurrence of trust.

Social network analysis (SNA) has been widely used to explore the existence and strength of connections among various actors within an organization. Recently, understanding and interpreting social aspects in project organization have gained great interest in project management research. Consequently, there is a need to analyse complex project organization (CPO) by using SNA with increasing numbers of large-scale and complex projects. The goal of this research is to better appreciate the social network relations in a CPO environment and to improve the organizational efficiency and team performance through new organizational control mechanisms (OCMs). This study first discusses a multi-level social network framework with a focus on the CPO where major analytical components of the framework are presented including modelling elements and structures and preferred parameters. Next, social network-oriented OCM and strategies are illustrated and compared with regular organizational controls. To examine the mentio...

Background Liver enriched natural killer (NK) cells are of high immune activity. However, the function of donor liver NK cells in allogeneic liver transplantation (LTx) remains unclear. Methods Ten Gy of whole body gamma-irradiation (WBI) from a 60 Co source at 0.6 Gy/min was used for depleting donor-derived leukocytes, and transfusion of purified liver NK cells isolated from the same type rat as donor (donor type liver NK cells, dtl NKs) through portal vein was performed immediately after grafting the irradiated liver. Post-transplant survival observation on recipients and histopathological detection of liver grafts were adoptive to evaluate the biological impact of donor liver NK cells on recipients' survival in rat LTx. Results Transfusion of dtl NKs did not shorten the survival time among the recipients of spontaneous tolerance model (BN to LEW rat) after rat LTx, but prolonged the liver graft survival among the recipients depleted of donor-derived leukocytes in the acute rejection model (LEW to BN rat). Compared to the recipients in the groups which received the graft depleted of donor-derived leukocytes, better survival and less damage in the allografts were also found among the recipients in the two different strain combinations of liver allograft due to transfusion of dtl NKs. Conclusions Donor liver NK cells alone do not exacerbate liver allograft acute rejection. Conversely, they can alleviate it, and improve the recipients' survival.

High-yield and high-purity bamboo-like boron nitride nanotubes were synthesized via an effective chemical vapor deposition method by annealing porous precursor under ammonia atmosphere at 1150 °C. The porous precursor, prepared by self-propagation high temperature synthesis method, was the key to bulk synthesis process. The as-synthesized boron nitride nanotubes were characterized by SEM, TEM, HRTEM, XRD, Raman and FTIR spectroscopy. These nanotubes had a bamboo-like structure with uniform diameters about 90 nm and length of more than 10 μm. The associated growth model is proposed in this paper.

The boron-doped diamond film (BDD) grown on tantalum (Ta) substrate as an electrode (BDD/Ta) was prepared by hot filament chemical vapor deposition method. The experimental results demonstrated that our BDD/Ta had high current efficiency, strong ability to degrade wastewater, good corrosion stability and long lifetime. These excellent characteristics of BDD/Ta have been explained in terms of Rutherford backscattering (RBS) experiments. RBS investigation revealed that the continuous transient layer at the interface between boron-doped diamond film and Ta-substrate was formed and the microstructure of the continuous transient layer given by the continuous distribution of all element contents at the interface was obtained. The thicknesses of boron-doped diamond film and the continuous transient layer were about equal to 8000 × 10 15 atoms/cm 2 and 5800 × 10 15 atoms/cm 2 , respectively. The formation of the continuous transient layer at the interface can eliminate the mismatch of thermal expansion coefficients (TEC) at the interface and only lead to the slow change of TEC because of the continuous distribution of element contents of the film and substrate in the transient layer at the interface. Thus, there is no residual stress to concentrate on the interface and the stress-corrosion delamination of the film disappears. Therefore, the corrosion stability and lifetime of BDD/Ta increase and last well, that have been verified by X-ray diffraction (XRD) experiments.

Kaposi sarcoma-associated herpesvirus (KSHV) ORF57, also known as Mta (mRNA transcript accumulation), enhances viral intron-less transcript accumulation and promotes splicing of intron-containing viral RNA transcripts. In this study, we identified KSHV PAN, a long non-coding polyadenylated nuclear RNA as a main target of ORF57 by a genome-wide CLIP (cross-linking and immunoprecipitation) approach. KSHV genome lacking ORF57 expresses only a minimal amount of PAN. In cotransfection experiments, ORF57 alone increased PAN expression by 20-30-fold when compared to vector control. This accumulation function of ORF57 was dependent on a structured RNA element in the 5' PAN, named MRE (Mta responsive element), but not much so on an ENE (expression and nuclear retention element) in the 3' PAN previously reported by other studies. We showed that the major function of the 5' PAN MRE is increasing the RNA half-life of PAN in the presence of ORF57. Further mutational analyses revealed a core motif consisting of 9 nucleotides in the MRE-II , which is responsible for ORF57 interaction and function. The 9-nt core in the MRE-II also binds cellular PABPC1, but not the E1B-AP5 which binds another region of the MRE-II. In addition, we found that PAN RNA is partially exportable in the presence of ORF57. Together, our data provide compelling evidence as to how ORF57 functions to accumulate a non-coding viral RNA in the course of virus lytic infection.

Kaposi sarcoma-associated herpesvirus (KSHV) ORF57, also known as Mta (mRNA transcript accumulation), enhances viral intron-less transcript accumulation and promotes splicing of intron-containing viral RNA transcripts. In this study, we identified KSHV PAN, a long non-coding polyadenylated nuclear RNA as a main target of ORF57 by a genome-wide CLIP (cross-linking and immunoprecipitation) approach. KSHV genome lacking ORF57 expresses only a minimal amount of PAN. In cotransfection experiments, ORF57 alone increased PAN expression by 20-30-fold when compared to vector control. This accumulation function of ORF57 was dependent on a structured RNA element in the 5' PAN, named MRE (Mta responsive element), but not much so on an ENE (expression and nuclear retention element) in the 3' PAN previously reported by other studies. We showed that the major function of the 5' PAN MRE is increasing the RNA half-life of PAN in the presence of ORF57. Further mutational analyses revealed a core motif consisting of 9 nucleotides in the MRE-II , which is responsible for ORF57 interaction and function. The 9-nt core in the MRE-II also binds cellular PABPC1, but not the E1B-AP5 which binds another region of the MRE-II. In addition, we found that PAN RNA is partially exportable in the presence of ORF57. Together, our data provide compelling evidence as to how ORF57 functions to accumulate a non-coding viral RNA in the course of virus lytic infection.

Emerging construction practices such as building information modelling (BIM), prefabrication construction, green building, and integrated project delivery methods are gaining momentum in China, with great potential due to the size of its construction market. Through this, the sustainability level of China&rsquo, s construction industry is expected to be enhanced from the economic, social and environmental perspectives. So far, there has been limited understanding of how BIM, as a digital technology, would affect other contemporary sustainable construction practices from the industry professionals&rsquo, point of view. Limited studies have been carried out to study the regional differences of these contemporary sustainable practices in China. This study adopted a questionnaire-based approach targeting industry professionals from three different metropolitan cities (Shanghai, Guangzhou, and Wenzhou).The follow-up comprehensive statistical analysis revealed that with regards to these contemporary sustainable construction practices, survey participants held much varied views on the growth of renovation projects, traditional Design&ndash, Bid&ndash, Build delivery, and conventional on-site construction methods. These three types were also generally perceived to have weak correlation with BIM application. Regional comparison further conveyed information on differences in perceptions among survey respondents from these three cities. For example, respondents from Wenzhou perceived more positive effects of BIM use in conventional construction projects. This research addressed the inter-correlation among these emerging sustainable construction practices, as well as the regional differences in China&rsquo, s construction market. The findings provide insights and the big picture for both governmental authorities and industry practitioners on the latest sustainable practices of China&rsquo, s construction industry. Recommendations are also offered towards improved economic, social and environmental sustainability performance for construction projects in the country.

Musashi1 (Msi1) is a highly conserved RNA-binding protein with pivotal functions in stem cell maintenance, nervous system development, and tumorigenesis. Despite its importance, only three direct mRNA targets have been characterized so far: m-numb, CDKN1A, and c-mos. Msi1 has been shown to affect their translation by binding to short elements located in the 3′-untranslated region. To better understand Msi1 functions, we initially performed an RIP-Chip analysis in HEK293T cells; this method consists of isolation of specific RNA-protein complexes followed by identification of the RNA component via microarrays. A group of 64 mRNAs was found to be enriched in the Msi1-associated population compared with controls. These genes belong to two main functional categories pertinent to tumorigenesis: 1) cell cycle, cell proliferation, cell differentiation, and apoptosis and 2) protein modification (including ubiquitination and ubiquitin cycle). To corroborate our findings, we examined the impact of Msi1 expression on both mRNA (transcriptomic) and protein (proteomic) expression levels. Genes whose mRNA levels were affected by Msi1 expression have a Gene Ontology distribution similar to RIP-Chip results, reinforcing Msi1 participation in cancer-related processes. The proteomics study revealed that Msi1 can have either positive or negative effects on gene expression of its direct targets. In summary, our results indicate that Msi1 affects a network of genes and could function as a master regulator during development and tumor formation.

International audience; The bias of A-rich codons in HIV-1 pol is thought to be a record of hypermutations in viral genomes that lack biological functions. Bioinformatic analysis predicted that A-rich sequences are generally associated with minimal local RNA structures. Using codon modifications to reduce the amount of A-rich sequences within HIV-1 genomes, we have reduced the flexibility of RNA sequences in pol to analyze the functional significance of these A-rich 'structurally poor' RNA elements in HIV-1 pol. Our data showed that codon modification of HIV-1 sequences led to a suppression of virus infectivity by 5-100-fold, and this defect does not correlate with, viral entry, viral protein expression levels, viral protein profiles or virion packaging of genomic RNA. Codon modification of HIV-1 pol correlated with an enhanced dimer stability of the viral RNA genome, which was associated with a reduction of viral cDNA synthesis both during HIV-1 infection and in a cell free reverse transcription assay. Our data provided direct evidence that the HIV-1 A-rich pol sequence is not merely an evolutionary artifact of enzyme-induced hypermutations, and that HIV-1 has adapted to rely on A-rich RNA sequences to support the synthesis of viral cDNA during reverse transcription, highlighting the utility of using 'structurally poor' RNA domains in regulating biological process.

Recent developments in the study of RNA silencing indicate that double-stranded RNA (dsRNA) can be used in eukaryotes to block expression of a corresponding cellular gene. There is also a large class of small non-coding RNAs having potential to form a distinct, stable stem-loop in numbers of eukaryotic genomes. We had reported that a large imperfect dsRNA structure with hundreds of base-pairs (bp) in the 3 ′ untranslated region ( 3 ′ UTR) of cytotoxic ribonuclease was correlated with the translation suppression. In this study, we search for such dsRNAs in a 3 ′ UTR database. The occurrence rate of large dsRNA in 3 ′ UTRs ranges from 0.01% in plant to 0.30% in vertebrate mRNAs. However, small imperfect dsRNAs of ∼ 30 bp are much more prevalent than large ones. The small dsRNAs are statistically very significant and uniquely well-ordered. Most of them have the conserved structural features of pre-miRNAs. Our data mining of the dsRNAs in the 3 ′ UTR database can be used to explore RNA-based regulation of gene expression.

A complex construction program usually consists of a group of interrelated projects with different levels of importance and degrees of certainty. Currently, time management of a construction program uses the same techniques as those for a single project, and the most commonly used technique is the critical path method (CPM). However, the CPM method lacks flexibility in handling uncertainties and options, a desirable feature in managing complex programs. This paper proposes a new scheduling method that is drawn from the authors’ experiences of managing a large-scale construction program—the Shanghai Expo facility construction. The new method is developed on the basis of the traditional CPM method but is able to incorporate options and importance levels into the program schedule. The theoretical basis and calculation method of this new scheduling technique are discussed in the context of managing the Shanghai Expo facility construction program. This paper contributes to the body of knowledge in cons...

Corruption has been identified as the greatest obstacle to economic and social development. Public construction projects, in particular, face high corruption risk as public construction sector has been consecutively deemed as the most corrupt one. Despite considerable efforts have been undertaken to measure corruption at a nation level, few researchers focus on the measurement of corruption in construction projects. This paper develops a fuzzy measurement model for the potential corruption in public construction projects in China. Through semistructured interviews with 14 experts, and then a questionnaire survey with 188 respondents, 24 measurement items of corruption were identified and further categorized into five constructs. The fuzzy set theory was then adopted to quantify each measurement item, construct, and the overall corruption level. This model can facilitate in evaluating, revealing, and monitoring corruption in public construction projects. Although this paper focuses on measuring cor...

Program management is increasingly regarded as a key approach to improving the performance of a construction megaproject through the coordinated management of its constituent projects. However, previous studies have seldom provided a pragmatic program management framework that can fully address the requirements of clients in managing construction megaprojects. Therefore, based on a case study of the Shanghai Expo construction, this study aims to identify the principal program organization factors (POFs) that are determinants of the program organization established by a client to manage a megaproject. Mixed research methods, such as case study, literature review, interviews, Delphi survey, and archival methods, are employed in this study. Consequently, 12 principal POFs, grouped under three main categories (environmental capability, core capacity, and motivational capability of the client’s program organization to manage its construction megaproject), are identified: (1) contextual understanding, (...

The rapid growth of construction megaprojects worldwide has triggered a growing number of papers published in this area in the past two decades, suggesting that construction megaproject management has become an emerging area in the field of construction engineering and management (CEM). This study aims to investigate the status and the trends in megaproject research by conducting a structured literature review. A total of 85 relevant articles identified from eight peer-reviewed CEM journals between 2000 and 2010 were analyzed based on the number of articles published annually, institutional and regional contributions, citations, and categorization of research interests and methodologies. Analysis results indicated that developed countries, such as the United Kingdom, the United States, and Australia, have enjoyed significant advantages in megaproject research because of their greater experience, while megaproject research in developing countries, such as Russia, India, Turkey, and Vietnam, remains...

Information and communication technology (ICT) has had enormous effects on the development of architecture, engineering, and construction (AEC) organizations in past decades. The effects have resonated in various disciplines, such as organizational efficiency, communication approach, and employee behavior. However, a comprehensive and in-depth review of the ICT applied in the AEC organization is missing from the current literature. To fill this gap, this paper presents an in-depth review of mainstream studies of ICT-supported AEC organizations published in last 15 years (1998–2012). A total of 145 articles from 12 construction and IT-related journals are identified and have been thoroughly reviewed. This review is divided into four parts: (1) synthesis and general trend of existing literature; (2) lessons learned from ICT practical implementation; (3) enabling technologies of ICT applications; and (4) ICT-induced organizational outcomes. Throughout this paper the authors summarize and categorize d...

Ni 3 Al base alloy was irradiated by intense pulsed ion beam (IPIB) with 250 kV acceleration voltage, 100–200 A/cm 2 current density and 60 ns pulse duration. The surface morphology and the cross-section microstructures were observed with SEM, and the compositions were characterized by XEDS. The results showed that the appearance of craters induced by irradiation is one of the major factors affecting the irradiated surface roughness; irradiation leads to composition changes on the surface of IC6 alloy and may improve mechanical properties of IC6 alloy.

Recent advances in RNA studies show that the well-ordered, structured RNAs perform a broad functions in various biological mechanisms. Included among these functions are regulations of gene expression at multiple levels by diversified ribozymes and various RNA regulatory elements. The discovered microRNAs (miRNAs) with a distinct stem-loops are a new class of RNA regulatory elements. The prediction of those well-ordered folding sequences (WFS) associated with the RNA regulatory elements in genomic sequences is very helpful for our understandings of RNA-based gene regulations. We present here a new computational method in searching for the conserved WFS in genomes. In the method, the WFS is assessed by a quantitative measure E diff that is defined as the difference of free energies between the computed optimal structure (OS) and its corresponding optimal restrained structure where all the previous base pairings in the OS are forbidden. From those WFS with high E diff scores, the conserved WFS is determined by computing the maximal similarity score (MSS) between the two compared structures. In practice, we first search for those distinct WFS with high statistical significance in genomic sequences and then seek for those conserved WFS with high MSS. The potential and implications of our discoveries in the genome of Caenorhabditis elegans are discussed.

The human c-myc proto-oncogene is transcribed from four alternative promoters generating transcripts with 5' untranslated regions of various lengths. These transcripts encode two proteins, c-Myc1 and c-Myc2, from two initiation codons, CUG and AUG, respectively. We and others have previously demonstrated that the region of c-myc transcripts between nucleotides (nt) –363 and –94 upstream from the CUG start codon contained an internal ribosome entry site leading to the cap-independent translation of c-myc open reading frames (ORFs). Here, we mapped a 50-nt sequence (-143 -94), which is sufficient to promote internal translation initiation of c-myc ORFs. Interestingly, this 50-nt element can be further dissected into two segments of 14 nt, each capable of activating internal translation initiation. We also demonstrate that this 50-nt element acts as the ribosome landing site from which the preinitiation ribosomal complex scans the mRNA until the CUG or AUG start codons., info:eu-repo/semantics/published

Parathyroid hormone (PTH) gene expression is regulated post-transcriptionally by hypocalcemia and hypophosphatemia. This regulation is dependent upon binding of protective trans-acting factors to a specific element in the PTH mRNA 3'-untranslated region (UTR). We have previously demonstrated that a 63-nucleotide (nt) AU-rich PTH mRNA element is sufficient to confer regulation of RNA stability by calcium and phosphate in an in vitro degradation assay (IVDA). The 63-nt element consists of a core 26-nt minimal binding sequence and flanking regions. We have now studied the functionality of this element in HEK293 cells using reporter genes and showed that it destabilizes mRNAs for green fluorescent protein (GFP) and growth hormone, similar to its effect in the IVDA. To understand how the cis-element functions as an instability element, we have analyzed its structure by RNase H, primer extension, and computer modeling. The results indicate that the PTH mRNA 3'-UTR and in particular the region of the cis-element are dominated by significant open regions with little folded base pairing. Mutation analysis of the 26-nt core element demonstrated the importance of defined nucleotides for protein-RNA binding. In the GFP reporter system, the same mutations that prevented binding were also ineffective in destabilizing GFP mRNA in HEK293 cells. This is the first study of an AU-rich element that relates function to structure. The PTH mRNA 3'-UTR cis-acting element is an open region that utilizes the distinct sequence pattern to determine mRNA stability by its interaction with trans-acting factors.

Motivation: Growing evidence demonstrates that local well-ordered structures are closely correlated with cis-acting elements in the post-transcriptional regulation of gene expression. The prediction of a well-ordered folding sequence (WFS) in genomic sequences is very helpful in the determination of local RNA elements with structure-dependent functions in mRNAs. Results: In this study, the quality of local WFS is assessed by the energy difference (Ediff) between the free energies of the global minimal structure folded in the segment and its corresponding optimal restrained structure (ORS). The ORS is an optimal structure under the condition in which none of the base-pairs in the global minimal structure is allowed to form. Those WFSs in HIV-1 mRNA, various ferritin mRNAs and genomic sequences containing let-7 RNA gene were searched by a novel method, ed_scan. Our results indicate that the detected WFSs are coincident with known Rev response element in HIV-1 mRNA, iron-responsive elements in ferritin mRNAs and small let-7 RNAs in Caenorhabditis elegans, Caenorhabditis briggsae and Drosophila melanogaster genomic sequences. Statistical significance of the WFS is addressed by a quantitative measure Zscre that is a z-score of Ediff and extensive random simulations. We suggest that WFSs with high statistical significance have structural roles involving their sequence information. Availability: The source code of ed_scan is available via anonymous ftp as ftp://ftp.ncifcrf.gov/pub/users/shuyun/scan/ed_scan.tar. Contact: shuyun@orleans.ncifcrf.gov * To whom correspondence should be addressed.

Numerous experiments and analyses of RNA structures have revealed that the local distinct structure closely correlates with the biological function. In this study, we present a data mining approach to discover such unusual folding regions (UFRs) in genome sequences. Our approach is a three-step procedure. During the first step, the quality of a local structure different from a random folding in a genomic sequence is evaluated by two z-scores, significance score (SIGSCR) and stability score (STBSCR) of the local segment. The two scores are computed by sliding a fixed window stepped a base along the sequence from the start to end position. Next, based on the non-central Student's t distribution theory we derive a linearly transformed non-central Student's t distribution (LTNSTD) to describe the distribution of SIGSCR and STBSCR computed in the sequence. In the third step, we extract these significant UFRs from the sequence whose SIGSCR and/or STBSCR are greater or less than a given threshold calculated from the derived LTNSTD. Our data mining approach is successfully applied to the complete genome of Mycoplasma genitalium (M. gen) and discovers these statistical extremes in the genome. By comparisons with the two scores computed from randomly shuffled sequences of the entire M. gen genome, our results demonstrate that the UFRs in the M. gen sequence are not selected by chance. These UFRs may imply an important structure role involved in their sequence information.