Comparison of two suspension control strategies for multi-axle heavy truck

Two simple and effective control strategies for a multi-axle heavy truck, modified skyhook damping (MSD) control and proportional-integration-derivative (PID) control, were implemented into functional virtual prototype (FVP) model and compared in terms of road friendliness and ride comfort. A four-axle heavy truck-road coupling system model was established using FVP technology and validated through a ride comfort test. Then appropriate passive air suspensions were chosen to replace the rear tandem suspensions of the original truck model for preliminary optimization. The mechanical properties and time lag of dampers were taken into account in simulations of MSD and PID semi-active dampers implemented using MATLAB/Simulink. Through co-simulations with Adams and MATLAB, the effects of semi-active MSD and PID control were analyzed and compared, and control parameters which afforded the best comprehensive performance for each control strategy were chosen. Simulation results indicate that compared with the passive air suspension truck, semi-active MSD control improves both ride comfort and road-friendliness markedly, with optimization ratios of RMS vertical acceleration and RMS tyre force ranging from 10.1% to 44.8%. However, semi-active PID control only reduces vertical vibration of the driver’s seat by 11.1%, 11.1% and 10.9% on A, B and C level roads respectively. Both strategies are robust to the variation of road level.

Osteogenic differentiation of bone marrow MSCs by β-tricalcium phosphate stimulating macrophages via BMP2 signalling pathway

Immune reactions play important roles in determining the in vivo fate of bone substitute materials, either in new bone formation or inflammatory fibrous tissue encapsulation. The paradigm for the development of bone substitute materials has been shifted from inert to immunomodulatory materials, emphasizing the importance of immune cells in the material evaluation. Macrophages, the major effector cells in the immune reaction to implants, are indispensable for osteogenesis and their heterogeneity and plasticity render macrophages a primer target for immune system modulation. However, there are very few reports about the effects of macrophages on biomaterial-regulated osteogenesis. In this study, we used b-tricalcium phosphate (b-TCP) as a model biomaterial to investigate the role of macrophages on the material stimulated osteogenesis. The macrophage phenotype switched to M2 extreme in response to b-TCP extracts, which was related to the activation of calcium-sensing receptor (CaSR) pathway. Bone morphogenetic protein 2 (BMP2) was also significantly upregulated by the b-TCP stimulation, indicating that macrophage may participate in the b-TCP stimulated osteogenesis. Interestingly, when macrophageconditioned b-TCP extracts were applied to bone marrow mesenchymal stem cells (BMSCs), the osteogenic differentiation of BMSCs was significantly enhanced, indicating the important role of macrophages in biomaterial-induced osteogenesis. These findings provided valuable insights into the mechanism of material-stimulated osteogenesis, and a strategy to optimize the evaluation system for the in vitro osteogenesis capacity of bone substitute materials.

Examining the effects of early cost drivers on contingencies

The accuracy of early cost estimates is critical to the success of construction projects. The selected tender price (clients' building cost) is usually seen in previous research as a holistic dependent variable when examining early stage estimates. Unlike other components of construction cost, the amount of contingencies is decided by clients/consultants with consideration of early project information. Cost drivers of contingencies estimates are associated with uncertainty and complexity, and include project size, schedule, ground condition, construction site access, market condition and so on. A path analysis of 133 UK school building contracts was conducted to identify impacts of nine major cost drivers on the determination of contingencies by different clients/cost estimators. This research finds that gross floor area (GFA), schedule and requirement of air conditioning have statistically significant impacts on the contingency determination. The mediating role of schedule between gross floor area and contingencies (GFA→Schedule→Contingencies) was confirmed with the Soble test. The total effects of the three variables on contingencies estimates were obtained with the consideration of this indirect effect. The squared multiple correlation (SMC) of contingencies (=0.624) indicates the identified three variables can explain 62.4% variance of contingencies, and it is comparatively satisfactory considering the heterogeneity among different estimators, unknown estimating techniques and different projects

H2AX phosphorylation screen of cells from radiosensitive cancer patients reveals a novel DNA double-strand break repair cellular phenotype

BACKGROUND: About 1-5% of cancer patients suffer from significant normal tissue reactions as a result of radiotherapy (RT). It is not possible at this time to predict how most patients' normal tissues will respond to RT. DNA repair dysfunction is implicated in sensitivity to RT particularly in genes that mediate the repair of DNA double-strand breaks (DSBs). Phosphorylation of histone H2AX (phosphorylated molecules are known as gammaH2AX) occurs rapidly in response to DNA DSBs, and, among its other roles, contributes to repair protein recruitment to these damaged sites. Mammalian cell lines have also been crucial in facilitating the successful cloning of many DNA DSB repair genes; yet, very few mutant cell lines exist for non-syndromic clinical radiosensitivity (RS). METHODS: Here, we survey DNA DSB induction and repair in whole cells from RS patients, as revealed by gammaH2AX foci assays, as potential predictive markers of clinical radiation response. RESULTS: With one exception, both DNA focus induction and repair in cell lines from RS patients were comparable with controls. Using gammaH2AX foci assays, we identified a RS cancer patient cell line with a novel ionising radiation-induced DNA DSB repair defect; these data were confirmed by an independent DNA DSB repair assay. CONCLUSION: gammaH2AX focus measurement has limited scope as a pre-RT predictive assay in lymphoblast cell lines from RT patients; however, the assay can successfully identify novel DNA DSB repair-defective patient cell lines, thus potentially facilitating the discovery of novel constitutional contributions to clinical RS.

Examining signs of driver sleepiness, usage of sleepiness countermeasures and the associations with sleepy driving behaviours and individual factors

The impairing effect from sleepiness is a major contributor to road crashes. The ability of a sleepy driver to perceive their level of sleepiness is an important consideration for road safety as well as the type of sleepiness countermeasure used by drivers as some sleepiness countermeasures are more effective than others. The aims of the current study were to determine the extent that the signs of driver sleepiness were associated with sleepy driving behaviours, as well as determining which individual factors (demographic, work, driving, and sleep-related factors) were associated with using a roadside or in-vehicle sleepiness countermeasure. A sample of 1518 Australian drivers from the Australian State of New South Wales and the neighbouring Australian Capital Territory took part in the study. The participants’ experiences with the signs of sleepiness were reasonably extensive. A number of the early signs of sleepiness (e.g., yawning, frequent eye blinks) were related with continuing to drive while sleepy, with the more advanced signs of sleepiness (e.g., difficulty keeping eyes open, dreamlike state of consciousness) associated with having a sleep-related close call. The individual factors associated with using a roadside sleepiness countermeasure included age (being older), education (tertiary level), difficulties getting to sleep, not continuing to drive while sleepy, and having experienced many signs of sleepiness. The results suggest that these participants have a reasonable awareness and experience with the signs of driver sleepiness. Factors related to previous experiences with sleepiness were associated with implementing a roadside countermeasure. Nonetheless, the high proportions of drivers performing sleepy driving behaviours, suggest that concerted efforts are needed with road safety campaigns regarding the dangers of driving while sleepy.

Common variants in the region around Osterix are associated with bone mineral density and growth in childhood

Peak bone mass achieved in adolescence is a determinant of bone mass in later life. In order to identify genetic variants affecting bone mineral density (BMD), we performed a genome-wide association study of BMD and related traits in 1518 children from the Avon Longitudinal Study of Parents and Children (ALSPAC). We compared results with a scan of 134 adults with high or low hip BMD. We identified associations with BMD in an area of chromosome 12 containing the Osterix (SP7) locus, a transcription factor responsible for regulating osteoblast differentiation (ALSPAC: P = 5.8 × 10-4; Australia: P = 3.7 × 10-4). This region has previously shown evidence of association with adult hip and lumbar spine BMD in an Icelandic population, as well as nominal association in a UK population. A meta-analysis of these existing studies revealed strong association between SNPs in the Osterix region and adult lumbar spine BMD (P = 9.9 × 10-11). In light of these findings, we genotyped a further 3692 individuals from ALSPAC who had whole body BMD and confirmed the association in children as well (P = 5.4 × 10-5). Moreover, all SNPs were related to height in ALSPAC children, but not weight or body mass index, and when height was included as a covariate in the regression equation, the association with total body BMD was attenuated. We conclude that genetic variants in the region of Osterix are associated with BMD in children and adults probably through primary effects on growth.

Impact of rRNA methylations on ribosome recycling and fidelity of initiation in Escherichia coli

Ribosomal RNA (rRNA) contains a number of modified nucleosides in functionally important regions including the intersubunit bridge regions. As the activity of ribosome recycling factor (RRF) in separating the large and the small subunits of the ribosome involves disruption of intersubunit bridges, we investigated the impact of rRNA methylations on ribosome recycling. We show that deficiency of rRNA methylations, especially at positions 1518 and 1519 of 16S rRNA near the interface with the 50S subunit and in the vicinity of the IF3 binding site, adversely affects the efficiency of RRF-mediated ribosome recycling. In addition, we show that a compromise in the RRF activity affords increased initiation with a mutant tRNA(fMet) wherein the three consecutive G-C base pairs ((29)GGG(31):39CCC41), a highly conserved feature of the initiator tRNAs, were mutated to those found in the elongator tRNA(Met) ((29)UCA(31):(39)psi GA(41)). This observation has allowed us to uncover a new role of RRF as a factor that contributes to fidelity of initiator tRNA selection on the ribosome. We discuss these and earlier findings to propose that RRF plays a crucial role during all the steps of protein synthesis.

Periodic Rayleigh waves of finite amplitude on an isotropic solid

Existence of a periodic progressive wave solution to the nonlinear boundary value problem for Rayleigh surface waves of finite amplitude is demonstrated using an extension of the method of strained coordinates. The solution, obtained as a second-order perturbation of the linearized monochromatic Rayleigh wave solution, contains harmonics of all orders of the fundamental frequency. It is shown that the higher harmonic content of the wave increases with amplitude, but the slope of the waveform remains finite so long as the amplitude is less than a critical value.

Periodic Rayleigh waves of finite amplitude on an isotropic solid

Existence of a periodic progressive wave solution to the nonlinear boundary value problem for Rayleigh surface waves of finite amplitude is demonstrated using an extension of the method of strained coordinates. The solution, obtained as a second-order perturbation of the linearized monochromatic Rayleigh wave solution, contains harmonics of all orders of the fundamental frequency. It is shown that the higher harmonic content of the wave increases with amplitude, but the slope of the waveform remains finite so long as the amplitude is less than a critical value.

Substituent effects on the addition of alcohols and anilines to organic isothiocyanates

The addition reactions of alcohols, ROH (R = CH3, C2H5 n-C3H7, i-C3H7 and t-C4H9), to p-bromophenylisothiocyanate show that the rates decrease in the order, CH3OH> C2H5OH> n-C3H7OH> i-C3H7OH> t-C4H9OH, although the basicities of the alcohols vary in the reverse order. The results indicate the greater importance of steric factors as compared with polar factors. Evidence is also presented for the formation of a complex between the isothiocyanate and the alcohol in the first stage of the addition reaction. In the addition of aniline to substituted phenylisothiocyanates the rate data give a satisfactory linear correlation with Hammett σ constants and the results clearly show that electron-withdrawing groups favour the addition reaction. The addition of aniline to alkyl isothiocyanates have been studied in order to find out the nature of alkyl group interaction in these derivatives. Kinetic studies on the addition of substituted anilines to phenylisothiocyanate show that the rate of reaction increases with the electron-donating ability of the substituents on the aniline as also the basicity of the aniline.

Unsteady mixed convection flow of a thermomicropolar fluid on a long thin vertical cylinder

The unsteady laminar mixed convection boundary layer flow of a thermomicropolar fluid over a long thin vertical cylinder has been studied when the free stream velocity varies with time. The coupled nonlinear partial differential equations with three independent variables governing the flow have been solved numerically using an implicit finite difference scheme in combination with the quasilinearization technique. The results show that the buoyancy, curvature and suction parameters, in general, enhance the skin friction, heat transfer and gradient of microrotation, but the effect of injection is just opposite. The skin friction and heat transfer for the micropolar fluid are considerably less than those for the Newtonian fluids. The effect of microrotation parameter is appreciable only on the microrotation gradient. The effect of the Prandtl number is appreciable on the skin friction, heat transfer and gradient of microtation.

Contactless conductivity of nanoparticles from electron magnetic resonance lineshape analysis

A contactless method to determine the electrical conductivity of nanoparticles is presented. It is based on the lineshape analysis of electron magnetic resonance signals which are `Dysonian' for conducting samples of sizes larger than the skin depth. The method is validated bymeasurements on a bulk sample of La0.67Sr0.33MnO3 where it gives values close to those obtained from direct measurement of conductivity and is then used to determine the conductivity of nanoparticles of La0.67Sr0.33MnO3 dispersed in polyvinyl alcohol as a function of temperature. (C) 2010 Elsevier Ltd. All rights reserved.

Teini-ikäisten tyttöjen ruokaturva Zambézian kaupungeissa ja maaseudulla

Johdanto Riittämätön ravinnonsaanti haittaa lasten fyysistä ja psyykkistä kasvua. Se myös heikentää Saharan eteläpuoleisen Afrikan tuottavuutta ja taloudellista kehitystä. Erityisen heikossa asemassa ovat lapset ja hedelmällisessä iässä olevat naiset johtuen nopean kasvun, raskauden ja imetyksen aiheuttamista vaatimuksista. Yleensä ruokaturvattomuus johtuu fyysisestä tai taloudellisesta ruoan hankintamahdollisuuden puuttumisesta ja on näin ollen läheisesti yhteydessä köyhyyteen sekä kestävien elinkeinojen ja turvaverkostojen puuttumiseen. Kaupungistumisen myötä monien afrikkalaisten elinkeinot, ruokatottumukset ja elämäntyyli ovat muuttuneet. Koska elämä kaupungeissa poikkeaa monin tavoin elämästä maaseudulla, myös ruokaturva ja sen taustalla olevat tekijät voivat olla erilaiset kaupungissa ja maaseudulla. Tällöin myös ruokaturvaohjelmat tulee suunnitella asuinpaikan mukaan ja kohdistaa voimavarat tarpeen mukaan. Harvat tutkimukset kuitenkaan tarkastelevat ruokaturvaa yhtä aikaa kaupungissa ja maaseudulla, mistä johtuen ruokaturvan erilaisuudesta näissä eri asuinympäristöissä on vähän tietoa. Tutkimuksen tavoite Tutkimuksen tarkoituksena on selvittää teini-ikäisten tyttöjen ruokaturvan taso Zambézian maakunnan maaseudulla ja kaupungeissa sekä tarkastella onko ruokaturva erilainen maaseudulla ja kaupungeissa. Lisäksi selvitetään mitkä tekijät ovat yhteydessä hyvään ruokaturvaan ja ovatko siihen yhteydessä olevat tekijät erilaisia näissä asuinympäristöissä. Aineisto ja menetelmät Tämä pro gradu -tutkielma on osa suomalais-mosambikilaista yhteistyöprojektia: Teini-ikäisten tyttöjen ravitsemus ja ruokavalio Zambéziassa (Estudo do Estado Nutricional e da Dieta em Raparigas Adolescentes na Zambézia). Tutkimus selvittää 15–18-vuotiaiden teinityttöjen ravitsemustilaa, ruokavaliota ja ruokaturvaa maaseudulla ja kaupunkiympäristössä Zambézian maakunnassa, ennen sadonkorjuuta ja sadonkorjuun jälkeen. Tämä osatutkimus perustuu ennen sadonkorjuuta tammi-helmikuussa 2010 kerättyyn aineistoon (n=277). Ruokaturvaa mitattiin Household Food Insecurity Access Scale (HFIAS) -kyselylomakkeella. Taustatietohaastattelusta poimittiin ruokaturvan kannalta mielenkiintoiset tekijät ja tarkasteltiin niiden yhteyttä ruokaturvaan. Tulokset Ruokaturvan havaittiin olevan huomattavasti parempi maaseudulla kuin kaupungissa. Maaseudulla kotieläimiä omistavat perheet kuuluivat harvemmin huonoon ruokaturvaluokkaan, kuin perheet jotka eivät omistaneet eläimiä. Kaupungissa ylimmässä varallisuustertiilissä olevat perheet kuuluivat keskimmäisessä varallisuustertiilissä olevia harvemmin huonoon ruokaturvaluokkaan. Maaseudun ja kaupungin välillä havaittavaa eroa ruokaturvassa selitti varallisuus. Johtopäätökset Maaseutua ja kaupunkeja tulisi ruokaturvatutkimuksissa käsitellä erillisinä tutkimuskohteina. Erilaiset ruokatottumukset saattavat vaikuttaa koettuun ruokaturvaan kaupungeissa ja maaseudulla. Ruokaturvan taustatekijät ovat myös erilaiset, jolloin ruokaturvattomuuden poistaminen vaatii eri toimintatapoja asuinpaikasta riippuen. Varallisuudella saattaa olla suurempi merkitys ruokaturvan kannalta kaupungeissa kuin maaseudulla. Varallisuuden ja ruokaturvan välisen yhteyden selvittäminen kaupungissa ja maaseudulla vaatii kuitenkin luotettavan varallisuusmittarin. Vuodenaika tulisi ottaa huomioon aiempaa paremmin kun tutkitaan kroonista ruokaturvattomuutta. Ruokaturvatutkimuksissa tulisi kerätä tietoa myös ruokavalion monipuolisuudesta ja tehdä antropometrisiä mittauksia, jotta ruokaturvasta saataisiin kokonaisvaltainen kuva.

X-ray studies on crystalline complexes involving amino acids and peptides. XXI. Structure of a (1:1) complex between L-phenylalanine and D-valine

CsHllNO2.C9HilNO2, Mr = 282.3, P1, a = 5.245 (1), b = 5.424 (1), c = 14.414 (2) A, a = 97.86 (1), fl = 93-69 (2), y = 70-48 (2) °, V= 356 A 3, Z = 1, O m = 1-32 (2), Dx = 1.32 g cm-3, h(Mo Ka) = 0-7107 A, g = 5-9 cm-1, F(000) = 158, T= 298 K, R=0.035 for 1518 observed reflections with I>2tr(I). The molecules aggregate in double layers, one ayer made up of L-phenylalanine molecules and the other of D-valine molecules. Each double layer is stabilized by interactions involving main-chain atoms of both types of molecules. The interactions include hydrogen bonds which give rise to two head-to-tail sequences. The arrangement of molecules in the complex is almost the same as that in the structure of DL-valine (and DL-leucine and DL-isoleucine) except for the change in the side chain of L molecules. The molecules in crystals containing an equal number of L and O hydrophobic amino-acid molecules thus appear to aggregate in a similar fashion, irrespective of the precise details of the side chain.