Improving megasite management performance through incentives : lessons learned from the Shanghai Expo construction

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).

Investigation on mechanical behaviour of AM60 magnesium alloys

Purpose: In this work, tension, impact, bend and fatigue tests were conducted in an AM60 magnesium alloy. The effects of environmental temperature and loading rates on impact and tension behavior of the alloy were also investigated. Design/methodology/approach: The tests were conducted using an Instron universal testing machine. The loading speed was changed from 1 mm/min to 300 mm/min to gain a better understanding of the effect of strain rate. To understand the failure behavior of this alloy at different environmental temperatures, Charpy impact test was conducted in a range of temperatures (-40~35°C). Plane strain fracture toughness (KIC) was evaluated using compact tension (CT) specimen. To gain a better understanding of the failure mechanisms, all fracture surfaces were observed using scanning electron microscopy (SEM). In addition, fatigue behavior of this alloy was estimated using tension test under tension-tension condition at 30 Hz. The stress amplitude was selected in the range of 20~50 MPa to obtain the S-N curve. Findings: The tensile test indicated that the mechanical properties were not sensitive to the strain rates applied (3.3x10-4~0.1) and the plastic deformation was dominated by twining mediated slip. The impact energy is not sensitive to the environmental temperature. The plane strain fracture toughness and fatigue limit were evaluated and the average values were 7.6 MPa.m1/2 and 25 MPa, respectively. Practical implications: Tested materials AM60 Mg alloy can be applied among others in automotive industry aerospace, communication and computer industry. Originality/value: Many investigations have been conducted to develop new Mg alloys with improved stiffness and ductility. On the other hand, relatively less attention has been paid to the failure mechanisms of Mg alloys, such as brittle fracture and fatigue, subjected to different environmental or loading conditions. In this work, tension, impact, bend and fatigue tests were conducted in an AM60 magnesium alloy.

Dynamic Micromapping of CO2 Sorption in Coal

We have applied X-ray and neutron small-angle scattering techniques (SAXS, SANS, and USANS) to study the interaction between fluids and porous media in the particular case of subcritical CO2 sorption in coal. These techniques are demonstrated to give unique, pore-size-specific insights into the kinetics of CO2 sorption in a wide range of coal pores (nano to meso) and to provide data that may be used to determine the density of the sorbed CO2. We observed densification of the adsorbed CO2 by a factor up to five compared to the free fluid at the same (p, T) conditions. Our results indicate that details of CO2 sorption into coal pores differ greatly between different coals and depend on the amount of mineral matter dispersed in the coal matrix: a purely organic matrix absorbs more CO2 per unit volume than one containing mineral matter, but mineral matter markedly accelerates the sorption kinetics. Small pores are filled preferentially by the invading CO2 fluid and the apparent diffusion coefficients have been estimated to vary in the range from 5 × 10-7 cm2/min to more than 10-4 cm2/min, depending on the CO2 pressure and location on the sample.

Genomic organisation, activity and distribution analysis of the microbial putrescine oxidase degradation pathway

The catalytic action of putrescine specific amine oxidases acting in tandem with 4-aminobutyraldehyde dehydrogenase is explored as a degradative pathway in Rhodococcus opacus. By limiting the nitrogen source, increased catalytic activity was induced leading to a coordinated response in the oxidative deamination of putrescine to 4-aminobutyraldehyde and subsequent dehydrogenation to 4-aminobutyrate. Isolating the dehydrogenase by ion exchange chromatography and gel filtration revealed that the enzyme acts principally on linear aliphatic aldehydes possessing an amino moiety. Michaelis-Menten kinetic analysis delivered a Michaelis constant (KM=0.014mM) and maximum rate (Vmax=11.2μmol/min/mg) for the conversion of 4-aminobutyraldehyde to 4-aminobutyrate. The dehydrogenase identified by MALDI-TOF mass spectrometric analysis (E value=0.031, 23% coverage) belongs to a functionally related genomic cluster that includes the amine oxidase, suggesting their association in a directed cell response. Key regulatory, stress and transport encoding genes have been identified, along with candidate dehydrogenases and transaminases for the further conversion of 4-aminobutyrate to succinate. Genomic analysis has revealed highly similar metabolic gene clustering among members of Actinobacteria, providing insight into putrescine degradation notably among Micrococcaceae, Rhodococci and Corynebacterium by a pathway that was previously uncharacterised in bacteria.

Cloning, expression, characterisation and mutational analysis of l-aspartate oxidase from Pseudomonas putida

L-Amino acid oxidases (LAAOs) are useful catalysts for the deracemisation of racemic amino acid sub-strates when combined with abiotic reductants. The gene nadB encoding the L-aspartate amino acid oxidase from Pseudomonas putida (PpLASPO) has been cloned and expressed in E. coli. The purified PpLASPO enzyme displayed a K M for l-aspartic acid of 2.26 mM and a k cat = 10.6 s −1 , with lower activity also displayed towards L-asparagine, for which pronounced substrate inhibition was also observed. The pH optimum of the enzyme was recorded at pH 7.4. The enzyme was stable for 60 min at up to 40 • C, but rapid losses in activity were observed at 50 • C. A mutational analysis of the enzyme, based on its sequence homology with the LASPO from E. coli of known structure, appeared to confirm roles in substrate binding or catalysis for residues His244, His351, Arg386 and Arg290 and also for Thr259 and Gln242. The high activity of the enzyme, and its promiscuous acceptance of both L-asparagine and L-glutamate as substrates, if with low activity, suggests that PpLASPO may provide a good model enzyme for evolution studies towards AAOs of altered or improved properties in the future.

A multi-hierarchical motorway ramp signalling strategy

Ramp signalling is an access control for motorways, in which a traffic signal is placed at on-ramps to regulate the rate of vehicles entering the motorway and thus to preserve the motorway capacity. In general, ramp signalling algorithms fall into two categories: local control and coordinated control by their effective scope. Coordinated ramp signalling strategies make use of measurements from the entire motorway network to operate individual ramp signals for the optimal performances at the network level. This study proposes a multi-hierarchical strategy for coordinated ramp signalling. The strategy is structured in two layers. At the higher layer with a longer update interval, coordination group is assembled and disassembled based on the location of high-risk breakdown flow. At the lower layer with a shorter update interval, individual ramps are hired to serve the coordination and are also released based on the prevailing congestion level on the ramp. This strategy is modelled and applied to the northbound Pacific Motorway micro-simulation platform (AIMSUN). The simulation results show an effective congestion mitigation of the proposed strategy.

Enantioselective epoxidation of linolenic acid catalysed by cytochrome P450BM3 from Bacillus megaterium

Cytochrome P450BM3, from Bacillus megaterium, catalyses the epoxidation of linolenic acid 1 yielding 15,16-epoxyoctadeca-9,12-dienoic acid 2 with complete regio- and moderate enantio-selectivity (60% ee). The absolute configuration of the product is tentatively assigned as 15(R),16(S)-. The Michaelis–Menten parameters kcat and Km for the reaction were determined to be 3126 ± 226 min−1 and 24 ± 6 μM respectively.

Stability of endoglucanases from mesophilic fungus and thermophilic bacterium in acidified polyols

Recent developments in chemical pretreatments of lignocellulosic biomass using polyols as co-solvents (e.g., glycerol and ethylene glycol) at temperatures less than 100 °C may allow the effective use of thermostable and non-thermostable cellulases in situ during the saccharification process. The potential of biomass saccharifying enzymes, endoglucanases (EG) from a thermophilic bacterium (Thermotoga maritima) and a mesophilic fungus (Trichoderma longibrachiatum), to retain their activity in aqueous buffer, acidified glycerol, and acidified ethylene glycol used as co-solvents at pretreatment temperatures at or below 100 °C were examined. The results show that despite its origin, T. longibrachiatum EG (Tl-EG) retained 75% of its activity after exposure to 100 °C for 5 min in aqueous buffer while T. maritima EG (Tm-EG) retained only 5% activity. However, at 90 °C both enzymes retained over 87% of their activity. In acidified (0.1% (w/w) H2SO4) glycerol, Tl-EG retained similar activity (80%) to that obtained in glycerol alone, while Tm-EG retained only 35%. With acidified ethylene glycol under these conditions, both Tl-EG and Tm-EG retained 36% of their activity. The results therefore show that Tl-EG is more stable in both acidified glycerol and ethylene glycol than Tm-EG. A preliminary kinetic study showed that pure glycerol improved the thermal stability of Tl-EG but destabilized Tm-EG, relative to the buffer solution. The half-lives of both Tl-EG and Tm-EG are 4.5 min in acidified glycerol, indicating that the effectiveness of these enzymes under typical pretreatment times of greater than 15 min will be considerably diminished. Attempts have been made to explain the differences in the results obtained between the two enzymes.

Matrix metalloproteinase-9 of tubular and macrophage origin contributes to the pathogenesis of renal fibrosis via macrophage recruitment through osteopontin cleavage

A pro-fibrotic role of matrix metalloproteinase-9 (MMP-9) in tubular cell epithelial-mesenchymal transition (EMT) is well established in renal fibrosis; however studies from our group and others have demonstrated some previously unrecognized complexity of MMP-9 that has been overlooked in renal fibrosis. Therefore, the aim of this study was to determine the expression pattern, origin and the exact mechanism underlying the contribution of MMP-9 to unilateral ureteral obstruction (UUO), a well-established model of renal fibrosis via MMP-9 inhibition. Renal MMP-9 expression in BALB/c mice with UUO was examined on day 1, 3, 5, 7, 9, 11 and 14. To inhibit MMP-9 activity, MMP-2/9 inhibitor or MMP-9-neutralizing antibody was administered daily for 4 consecutive days from day 0-3, 6-9 or 10-13 and tissues harvested at day 14. In UUO, there was a bi-phasic early- and late-stage upregulation of MMP-9 activity. Interestingly, tubular epithelial cells (TECs) were the predominant source of MMP-9 during early stage, whereas TECs, macrophages and myofibroblasts produced MMP-9 during late-stage UUO. Early- and late-stage inhibition of MMP-9 in UUO mice significantly reduced tubular cell EMT and renal fibrosis. Moreover, MMP-9 inhibition caused a significant reduction in MMP-9-cleaved osteopontin and macrophage infiltration in UUO kidney. Our in vitro study showed MMP-9-cleaved osteopontin enhanced macrophage transwell migration and MMP-9 of both primary TEC and macrophage induced tubular cell EMT. In summary, our result suggests that MMP-9 of both TEC and macrophage origin may directly or indirectly contribute to the pathogenesis of renal fibrosis via osteopontin cleavage, which, in turn further recruit macrophage and induce tubular cell EMT. Our study also highlights the time dependency of its expression and the potential of stage-specific inhibition strategy against renal fibrosis.

Mini-scale method for nuclear run-on transcription assay in plants

We present a mini-scale method for nuclear run-on transcription assay. In our method, all the centrifuge steps can be carried out by using micro-tubes for short time (5 min each) throughout the process, including isolation of transcriptionally active nuclei and purification of labeled RNA after synthesis of RNA in isolated nuclei. The assay can be performed using a small amount of plant tissue, which enables analysis of developmental changes in transcriptional status of given genes in a single individual plant. Successful results were obtained using the tissues of flower and leaf of petunia and embryo of pea, suggesting that the method is potentially applicable to a variety of plant tissues.

Commissioning of a new commercial plastic scintillator system for radiotherapy

Introduction Since 1992 there have been several articles published on research on plastic scintillators for use in radiotherapy. Plastic scintillators are said to be tissue equivalent, temperature independent and dose rate independent [1]. Although their properties were found to be promising for measurements in megavoltage X-ray beams there were some technical difficulties with regards to its commercialisation. Standard Imaging has produced the first commercial system which is now available for use in a clinical setting. The Exradin W1 scintillator device uses a dual fibre system where one fibre is connected to the Plastic Scintillator and the other fibre only measures Cerenkov radiation [2]. This paper presents results obtained during commissioning of this dosimeter system. Methods All tests were performed on a Novalis Tx linear accelerator equipped with a 6 MV SRS photon beam and conventional 6 and 18 MV X-ray beams. The following measurements were performed in a Virtual Water phantom at a depth of dose maximum. Linearity: The dose delivered was varied between 0.2 and 3.0 Gy for the same field conditions. Dose rate dependence: For this test the repetition rate of the linac was varied between 100 and 1,000 MU/min. A nominal dose of 1.0 Gy was delivered for each rate. Reproducibility: A total of five irradiations for the same setup. Results The W1 detector gave a highly linear relationship between dose and the number of Monitor Units delivered for a 10 9 10 cm2 field size at a SSD of 100 cm. The linearity was within 1 % for the high dose end and about 2 % for the very low dose end. For the dose rate dependence, the dose measured as a function of repetition the rate (100–1,000 MU/min) gave a maximum deviation of 0.9 %. The reproducibility was found to be better than 0.5 %. Discussion and conclusions The results for this system look promising so far being a new dosimetry system available for clinical use. However, further investigation is needed to produce a full characterisation prior to use in megavoltage X-ray beams.

Age and gender differences in objectively measured physical activity in youth

Purpose The purpose of this study was to evaluate age and gender differences in objectively measured physical activity (PA) in a population-based sample of students in grades 1–12. Methods Participants (185 male, 190 female) wore a CSA 7164 accelerometer for 7 consecutive days. To examine age-related trends, students were grouped as follows: grades 1–3 (N = 90), grades 4–6 (N = 91), grades 7–9 (N = 96), and grades 10–12 (N = 92). Bouts of PA and minutes spent in moderate-to-vigorous PA (MVPA) and vigorous PA (VPA) were examined. Results Daily MVPA and VPA exhibited a significant inverse relationship with grade level, with the largest differences occurring between grades 1–3 and 4–6. Boys were more active than girls; however, for overall PA, the magnitudes of the gender differences were modest. Participation in continuous 20-min bouts of PA was low to nonexistent. Conclusion Our results support the notion that PA declines rapidly during childhood and adolescence and that accelerometers are feasible alternatives to self-report methods in moderately sized population-level surveillance studies.

Conducting accelerometer-based activity assessments in field-based research

Purpose The purpose of this review is to address important methodological issues related to conducting accelerometer-based assessments of physical activity in free-living individuals. Methods We review the extant scientific literature for empirical information related to the following issues: product selection, number of accelerometers needed, placement of accelerometers, epoch length, and days of monitoring required to estimate habitual physical activity. We also discuss the various options related to distributing and collecting monitors and strategies to enhance compliance with the monitoring protocol. Results No definitive evidence exists currently to indicate that one make and model of accelerometer is more valid and reliable than another. Selection of accelerometer therefore remains primarily an issue of practicality, technical support, and comparability with other studies. Studies employing multiple accelerometers to estimate energy expenditure report only marginal improvements in explanatory power. Accelerometers are best placed on hip or the lower back. Although the issue of epoch length has not been studied in adults, the use of count cut points based on 1-min time intervals maybe inappropriate in children and may result in underestimation of physical activity. Among adults, 3–5 d of monitoring is required to reliably estimate habitual physical activity. Among children and adolescents, the number of monitoring days required ranges from 4 to 9 d, making it difficult to draw a definitive conclusion for this population. Face-to-face distribution and collection of accelerometers is probably the best option in field-based research, but delivery and return by express carrier or registered mail is a viable option. Conclusion Accelerometer-based activity assessments requires careful planning and the use of appropriate strategies to increase compliance.

Physical activity and determinants of physical activity in obese and non-obese children

OBJECTIVE To compare the physical activity (PA) patterns and the hypothesized psychosocial and environmental determinants of PA in an ethnically diverse sample of obese and non-obese middle school children. DESIGN Cross-sectional study. SUBJECTS One-hundred and thirty-three non-obese and 54 obese sixth grade children (mean age of 11.4 +/-0.6). Obesity status determined using the age-, race- and gender-specific 95th percentile for BMI from NHANES-1. MEASUREMENTS Objective measurements were collected of PA over a 7-day period using the CSA 7164 accelerometer: total daily counts; daily moderate (3-5.9 METs) physical activity (MPA); daily vigorous physical activity (greater than or equal to 6 METs; VPA); and weekly number of 5, 10 and 20 min bouts of moderate-to-vigorous physical activity (greater than or equal to 3 METs, MVPA). Self-report measures were collected of PA self-efficacy; social influences regarding PA, beliefs about PA outcomes; perceived PA levels of parents and peers, access to sporting and/or fitness equipment at home, involvement in community-based PA organizations; participation in community sports teams; and hours spent watching television or playing video games. RESULTS Compared to their non-obese counterparts, obese children exhibited significantly lower daily accumulations of total counts, MPA and VPA as well as significantly fewer 5, 10 and 20 min bouts of MVPA. Obese children reported significantly lower levels of PA self-efficacy, were involved in significantly fewer community organizations promoting PA and were significantly less likely to report their father or male guardian as physically active. CONCLUSIONS The results are consistent with the hypothesis that physical inactivity is an important contributing factor in the maintenance of childhood obesity. Interventions to promote PA in obese children should endeavor to boost self-efficacy perceptions regarding exercise, increase awareness of, and access to, community PA outlets, and increase parental modeling of PA.

The effect of exercise on the skeletal muscle phospholipidome of rats fed a high-fat diet

The aim of this study was to examine the effect of endurance training on skeletal muscle phospholipid molecular species from high-fat fed rats. Twelve female Sprague-Dawley rats were fed a high-fat diet (78.1% energy). The rats were randomly divided into two groups, a sedentary control group and a trained group (125 min of treadmill running at 8 m/min, 4 days/wk for 4 weeks). Forty-eight hours after their last training bout phospholipids were extracted from the red and white vastus lateralis and analyzed by electrospray-ionization mass spectrometry. Exercise training was associated with significant alterations in the relative abundance of a number of phospholipid molecular species. These changes were more prominent in red vastus lateralis than white vastus lateralis. The largest observed change was an increase of similar to 30% in the abundance of 1-palmitoyl-2-linoleoyl phosphatidylcholine ions in oxidative fibers. Reductions in the relative abundance of a number of phospholipids containing long-chain n-3 polyunsaturated fatty acids were also observed. These data suggest a possible reduction in phospholipid remodeling in the trained animals. This results in a decrease in the phospholipid n-3 to n-6 ratio that may in turn influence endurance capacity.