bluuebunny/crossref_metadata_2025 huggingface dataset:
Incorporation of podoplanin into HIV released from HEK-293T cells, but not PBMC, is required for efficient binding to the attachment factor CLEC-2
Authors: Chaipan Chawaree , Steffen Imke , Tsegaye Theodros Solomon , Bertram Stephanie , Glowacka Ilona , Kato Yukinari , Schmökel Jan , Münch Jan , Simmons Graham , Gerardy-Schahn Rita , Pöhlmann Stefan
Published: May 2010

Background

Platelets are associated with HIV in the blood of infected individuals and might modulate viral dissemination, particularly if the virus is directly transmitted into the bloodstream. The C-type lectin DC-SIGN and the novel HIV attachment factor CLEC-2 are expressed by platelets and facilitate HIV transmission from platelets to T-cells. Here, we studied the molecular mechanisms behind CLEC-2-mediated HIV-1 transmission.

Results

Binding studies with soluble proteins indicated that CLEC-2, in contrast to DC-SIGN, does not recognize the viral envelope protein, but a cellular factor expressed on kidney-derived 293T cells. Subsequent analyses revealed that the cellular mucin-like membranous glycoprotein podoplanin, a CLEC-2 ligand, was expressed on 293T cells and incorporated into virions released from these cells. Knock-down of podoplanin in 293T cells by shRNA showed that virion incorporation of podoplanin was required for efficient CLEC-2-dependent HIV-1 interactions with cell lines and platelets. Flow cytometry revealed no evidence for podoplanin expression on viable T-cells and peripheral blood mononuclear cells (PBMC). Podoplanin was also not detected on HIV-1 infected T-cells. However, apoptotic bystander cells in HIV-1 infected cultures reacted with anti-podoplanin antibodies, and similar results were obtained upon induction of apoptosis in a cell line and in PBMCs suggesting an unexpected link between apoptosis and podoplanin expression. Despite the absence of detectable podoplanin expression, HIV-1 produced in PBMC was transmitted to T-cells in a CLEC-2-dependent manner, indicating that T-cells might express an as yet unidentified CLEC-2 ligand.

Conclusions

Virion incorporation of podoplanin mediates CLEC-2 interactions of HIV-1 derived from 293T cells, while incorporation of a different cellular factor seems to be responsible for CLEC-2-dependent capture of PBMC-derived viruses. Furthermore, evidence was obtained that podoplanin expression is connected to apoptosis, a finding that deserves further investigation.
Brief Communication: Sexual dimorphic expression of myostatin and follistatin like-3 in a rat trans-generational under-nutrition model
Authors: Peiris Hassendrini N , Ponnampalam Anna P , Mitchell Murray D , Green Mark P
Published: May 2010

The detrimental effects of maternal under-nutrition during gestation on fetal development are well known with an increased propensity of metabolic disorders identified in the adult offspring. Understanding exactly how and by which molecular pathways inadequate nutrition can impact upon offspring phenotype is critical and necessary for the development of treatment methods and ultimately prevention of any negative health effects. Myostatin, a negative regulator of muscle development, has recently been shown to effect glucose homeostasis and fat deposition. The involvement of myostatin in glucose metabolism and adipogenesis thus supports its ability to act in the continued alterations to the postnatal phenotype of the offspring. This hypothesis was examined in the current study using a trans-generational gestationally under-nourished rat model exposed to a high-fat (HF) diet post-weaning. The body weight, body fat, plasma glucose and insulin concentrations of the offspring, both male and female, were investigated in relation to the protein expression of myostatin and its main inhibitor; follistatin like-3 (FSTL-3), in skeletal muscle of mature offspring. Sexual dimorphism was clearly evident in the majority of these measures, including myostatin and FSTL-3 expression. Generally males displayed higher (P < 0.05) myostatin precursor and dimer expression than females, which was especially apparent (P < 0.01) in both chow and HF trans-generationally undernourished (UNAD) groups. In females only, myostatin precursor and dimer expression was altered by both trans-generational under-nutrition and postnatal diet. Overall FSTL-3 expression did not differ between sexes, although difference between sexes within certain treatments and diets were evident. Most notably, HF fed UNAD females had higher (P < 0.05) FSTL-3 expression than HF fed UNAD males. The former group also displayed higher (P < 0.01) FSTL-3 expression compared to all other female groups. In summary, myostatin may prove to be a key mediator of the effects of inadequate prenatal nutrition, independently or in combination with a high-fat postnatal diet on offspring phenotype. Consequently, further study of myostatin may provide a novel therapeutic pathway for the treatment of metabolic disorders; however, it is vital that the influence of nutrition and gender should be taken into consideration.
The value of ultrasonography in predicting arthritis in auto-antibody positive arthralgia patients: a prospective cohort study
Authors: van de Stadt Lotte A , Bos Wouter H , Meursinge Reynders Marlies , Wieringa Helen , Turkstra Franktien , van der Laken Conny J , van Schaardenburg Dirkjan
Published: May 2010

Introduction

Ultrasonography (US) has better sensitivity than clinical evaluation for the detection of synovitis in early rheumatoid arthritis (RA). Patients presenting with arthralgia and a positive anti-citrullinated protein antibodies (ACPA) and/or Rheumatoid Factor (IgM-RF) status are at risk for developing RA. In the present study, US utility and predictive properties in arthralgia patients at risk for the development of arthritis were studied.

Methods

192 arthralgia patients with ACPA and/or IgM-RF were included. Absence of clinical arthritis was confirmed by two physicians. US was performed by one of two trained radiologists of any painful joint, and of adjacent and contralateral joints. Joint effusion, synovitis and power Doppler (PD) signal in the synovial membrane of the joints and tenosynovitis adjacent to the joint were evaluated and classified on a 4-grade semi-quantitative scale. Grade 2-3 joint effusion, synovitis, tenosynovitis and grade 1-3 Power Doppler signal were classified as abnormal.

Results

Forty-five patients (23%) developed arthritis after a mean of 11 months. Inter-observer reliability for synovitis and PD was moderate (kappa 0.46, and 0.56, respectively) and for joint effusion low (kappa 0.23). The prevalence of tenosynovitis was too low to calculate representative kappa values. At joint level, a significant association was found between US abnormalities and arthritis development in that joint for joint effusion, synovitis and PD. At patient level, a trend was seen towards more arthritis development in patients who had US abnormalities for joint effusion, synovitis, PD and tenosynovitis.

Conclusions

US abnormalities were associated with arthritis development at joint level, although this association did not reach statistical significance at patient level. US could potentially be used as a diagnostic tool for subclinical arthritis in seropositive arthralgia patients. However, further research is necessary to improve test characteristics.
Clinical and serological evaluation of a novel CENP-A peptide based ELISA
Authors: Mahler Michael , Maes Liesbeth , Blockmans Daniel , Westhovens Rene , Bossuyt Xavier , Riemekasten Gabriela , Schneider Sandra , Hiepe Falk , Swart Andreas , Gürtler Irmgard , Egerer Karl , Fooke Margrit , Fritzler Marvin J
Published: May 2010

Introduction

Anti-centromere antibodies (ACA) are useful biomarkers in the diagnosis of systemic sclerosis (SSc). ACA are found in 20 to 40% of SSc patients and, albeit with lower prevalence, in patients with other systemic autoimmune rheumatic diseases. Historically, ACA were detected by indirect immunofluorescence (IIF) on HEp-2 cells and confirmed by immunoassays using recombinant CENP-B. The objective of this study was to evaluate a novel CENP-A peptide ELISA.

Methods

Sera collected from SSc patients (n = 334) and various other diseases (n = 619) and from healthy controls (n = 175) were tested for anti-CENP-A antibodies by the novel CENP-A enzyme linked immunosorbent assay (ELISA). Furthermore, ACA were determined in the disease cohorts by IIF (ImmunoConcepts, Sacramento, CA, USA), CENP-B ELISA (Dr. Fooke), EliA® CENP (Phadia, Freiburg, Germany) and line-immunoassay (LIA, Mikrogen, Neuried, Germany). Serological and clinical associations of anti-CENP-A with other autoantibodies were conducted in one participating centre. Inhibition experiments with either the CENP-A peptide or recombinant CENP-B were carried out to analyse the specificity of anti-CENP-A and -B antibodies.

Results

The CENP-A ELISA results were in good agreement with other ACA detection methods. According to the kappa method, the qualitative agreements were: 0.73 (vs. IIF), 0.81 (vs. LIA), 0.86 (vs. CENP-B ELISA) and 0.97 (vs. EliA® CENP). The quantitative comparison between CENP-A and CENP-B ELISA using 265 samples revealed a correlation value of rho = 0.5 (by Spearman equation). The receiver operating characteristic analysis indicated that the discrimination between SSc patients (n = 131) and various controls (n = 134) was significantly better using the CENP-A as compared to CENP-B ELISA (P < 0.0001). Modified Rodnan skin score was significantly lower in the CENP-A negative group compared to the positive patients (P = 0.013). Inhibition experiments revealed no significant cross reactivity of anti-CENP-A and anti-CENP-B antibodies. Statistically relevant differences for gender ratio (P = 0.0103), specific joint involvement (Jaccoud) (P = 0.0006) and anti-phospholipid syndrome (P = 0.0157) between ACA positive SLE patients and the entire SLE cohort were observed.

Conclusions

Anti-CENP-A antibodies as determined by peptide ELISA represent a sensitive, specific and independent marker for the detection of ACA and are useful biomarkers for the diagnosis of SSc. Our data suggest that anti-CENP-A antibodies are a more specific biomarker for SSc than antibodies to CENP-B. Furthers studies are required to verify these findings.
Genistein Induces Pancreatic β-Cell Proliferation through Activation of Multiple Signaling Pathways and Prevents Insulin-Deficient Diabetes in Mice
Authors: Fu Zhuo , Zhang Wen , Zhen Wei , Lum Hazel , Nadler Jerry , Bassaganya-Riera Josep , Jia Zhenquan , Wang Yanwen , Misra Hara , Liu Dongmin
Published: May 2010

Genistein, a flavonoid in legumes and some herbal medicines, has various biological actions. However, studies on whether genistein has an effect on pancreatic β-cell function are very limited. In the present study, we investigated the effect of genistein on β-cell proliferation and cellular signaling related to this effect and further determined its antidiabetic potential in insulin-deficient diabetic mice. Genistein induced both INS1 and human islet β-cell proliferation after 24 h of incubation, with 5 μm genistein inducing a maximal 27% increase. The effect of genistein on β-cell proliferation was neither dependent on estrogen receptors nor shared by 17β-estradiol or a host of structurally related flavonoid compounds. Pharmacological or molecular intervention of protein kinase A (PKA) or ERK1/2 completely abolished genistein-stimulated β-cell proliferation, suggesting that both molecules are essential for genistein action. Consistent with its effect on cell proliferation, genistein induced cAMP/PKA signaling and subsequent phosphorylation of ERK1/2 in both INS1 cells and human islets. Furthermore, genistein induced protein expression of cyclin D1, a major cell-cycle regulator essential for β-cell growth. Dietary intake of genistein significantly improved hyperglycemia, glucose tolerance, and blood insulin levels in streptozotocin-induced diabetic mice, concomitant with improved islet β-cell proliferation, survival, and mass. These results demonstrate that genistein may be a natural antidiabetic agent by directly modulating pancreatic β-cell function via activation of the cAMP/PKA-dependent ERK1/2 signaling pathway.
Prolactin-Induced Mitogenesis in the Subventricular Zone of the Maternal Brain during Early Pregnancy Is Essential for Normal Postpartum Behavioral Responses in the Mother
Authors: Larsen Caroline M. , Grattan David R.
Published: May 2010

High prolactin during pregnancy, which is essential for normal postpartum maternal behavior, increases neurogenesis in the subventricular zone of the lateral ventricle (SVZ) of the maternal brain. Because SVZ mitogenesis generates new olfactory neurons and may contribute to perception of novel odorants, we hypothesized that the prolactin-induced increase in SVZ mitogenesis during pregnancy might be important for normal maternal interactions with pups. To investigate this hypothesis, prolactin secretion was suppressed for 3 d early in pregnancy in mice, using a carefully timed dose of bromocriptine. The bromocriptine-induced reduction in prolactin prevented the normal increase in generation of neural progenitors in the SVZ of the maternal brain. Another group of bromocriptine-treated animals were allowed to continue their pregnancy until term, and then maternal behaviors were evaluated postpartum. Low prolactin during early pregnancy, and the consequent suppression of mitogenesis in the SVZ of the maternal brain, was subsequently followed by increased postpartum anxiety and markedly impaired maternal behavior. In another group of pregnant females, injections of the mitotic inhibitor methylazoxymethanol to specifically suppress neurogenesis in the mother during early pregnancy without affecting prolactin secretion also caused postpartum anxiety and impaired maternal behavior. These data demonstrate that prolactin-induced increase in generation of neural progenitors in the SVZ of the maternal brain during early pregnancy is required for normal expression of postpartum maternal behaviors.
Estradiol Increases the Anorectic Effect of Central Apolipoprotein A-IV
Authors: Shen Ling , Wang David Q.-H. , Lo Chun-min , Tso Patrick , Davidson W. Sean , Woods Stephen C. , Liu Min
Published: May 2010

Estrogens have potent suppressive effects on food intake and body weight in many species, including humans. Compelling evidence suggests estrogen’s anorectic action is through an indirect mechanism by enhancing the strength of other physiological signals that reduce meal size such as apolipoprotein A-IV (apo A-IV), a satiation factor from the gut and brain. We determined whether estradiol, the primary form of estrogen, modulates the anorectic effect of apo A-IV. Intrafourth ventricular administration of low doses of apo A-IV reduced food intake to a greater extent in ovariectomized (OVX) rats cyclically treated with estradiol than in vehicle-treated OVX controls, implying that cyclic estradiol replacement increases the satiating potency of apo A-IV. OVX significantly increased food intake and body weight but decreased apo A-IV gene expression in the nucleus tractus solitarius (NTS). All of these alterations were reversed by cyclic regimen of estradiol treatment. The finding of colocalization of apo A-IV with estrogen receptor-α in the NTS suggests that estradiol might act locally in the NTS to up-regulate apo A-IV gene expression. Finally, OVX apo A-IV knockout mice had a smaller feeding response to estradiol because they ate significantly more food and gained more body weight than OVX wild-type controls during the period of cyclic estradiol replacement. These data indicate that an increased signaling of endogenous apo A-IV may partially mediate estradiol-induced inhibitory effect on feeding.
Minireview: Role of Kinases and Chromatin Remodeling in Progesterone Signaling to Chromatin
Authors: Vicent Guillermo P. , Nacht A. Silvina , Zaurín Roser , Ballaré Cecilia , Clausell Jaime , Beato Miguel
Published: May 2010

Steroid hormones regulate gene expression by interaction of their receptors with hormone-responsive elements on DNA or with other transcription factors, but they can also activate cytoplasmic signaling cascades. Rapid activation of Erk by progestins via an interaction of the progesterone receptor (PR) with the estrogen receptor is critical for transcriptional activation of the mouse mammary tumor virus (MMTV) promoter and other progesterone target genes. Erk activation leads to the phosphorylation of PR, activation of mitogen- and stress-activated protein kinase 1, and the recruitment of a complex of the three activated proteins and of P300/CBP-associated factor (PCAF) to a single nucleosome, resulting in the phosphoacetylation of histone H3 and the displacement of heterochromatin protein 1γ. Hormone-dependent gene expression requires ATP-dependent chromatin remodeling complexes. Two switch/sucrose nonfermentable-like complexes, Brahma-related gene 1-associated factor (BAF) and polybromo-BAF are present in breast cancer cells, but only BAF is recruited to the MMTV promoter and cooperates with PCAF during activation of hormone-responsive promoters. PCAF acetylates histone H3 at K14, an epigenetic mark recognized by BAF subunits, thus anchoring the complex to chromatin. BAF catalyzes localized displacement of histones H2A and H2B, facilitating access of nuclear factor 1 and additional PR complexes to the hidden hormone-responsive elements on the MMTV promoter. The linker histone H1 is a structural component of chromatin generally regarded as a general repressor of transcription. However, it contributes to a better regulation of the MMTV promoter by favoring a more homogeneous nucleosome positioning, thus reducing basal transcription and actually enhancing hormone induced transcription. During transcriptional activation, H1 is phosphorylated and displaced from the promoter. The kinase cyclin-dependent kinase 2 is activated after progesterone treatment and could catalyze progesterone-induced phosphorylation of histone H1 by chromatin remodeling complexes. The initial steps of gene induction by progestins involve changes in the chromatin organization of target promoters that require the activation of several kinase signaling pathways initiated by membrane anchored PR. Because these pathways also respond to other external signals, they serve to integrate the hormonal response in the global context of the cellular environment.
The Diffusion of Terrorism
Authors: Pillar Paul R.
Published: May 2010

The prevailing perception of the threat from international terrorism is that it emanates chiefly from one group, al Qaeda, it is tied to a territorial presence in South Asia, and it is driven by a fixed ideology bent on inflicting maximum damage on the West. The perception stems more from Western fears and the legacy of past experience than from actual trends in terrorism. The real threat is more diffuse and decentralized, not embodied in any one group or piece of territory, and has more malleable goals and tactics.
Obama and the Middle East Peace Process: Challenge and Response
Authors: El-Khawas Mohamed A.
Published: May 2010

The author examines the steps taken by the new administration to resolve the decades-old Israeli-Palestinian conflict. The search for a solution requires dealing with many players with conflicting interests and contradictory agendas. President Obama's relaunch of the Middle East peace process soon ran into problems. His two-state solution was not endorsed by Israel's Prime Minister Benjamin Netanyahu until June 2009. President Obama's early call for a settlement freeze in the occupied territories was hailed by the Palestinians, but US envoy George Mitchell was able to get Netanyahu to agree only to a partial freeze, which was rejected by Palestinian Authority President Mahmoud Abbas. Obama's subsequent retreat on a settlement freeze shocked the Palestinians, who refused to start the peace talks.
Bent Hemingway
Authors: Pierre Scott St.
Published: May 2010

It is an often taken-for-granted assumption about Ernest Hemingway that his famously simple and clear style reflects his mercilessly heteromasculine self-presentation. This essay challenges that prominent reading by examining the cultural connections between literary style and sexuality that that reading both reflects and reproduces. Reading Hemingway's fiction with attention to the sexual dimension that has so often circulated in criticism of him, the essay shows modern Western culture's preoccupation with celebrating heterosexuality in the form of its praise of simplicity and clarity, even as it denigrates homosexuality under the sign of ornament and decoration.
Robot-assisted endoscopic exploration of the spinal cord
Authors: Ascari L , Stefanini C , Bertocchi U , Dario P
Published: May 2010

This work presents the design and development of an integrated image-guided robot-assisted endoscopic system for the safe navigation within the spinal subarachnoid space, providing the surgeon with the direct vision of the structures (i.e. spinal cord, roots, vessels) and the possibility of performing some particularly useful operations, like local electrostimulation of nerve roots. The modelling, micro-fabrication, fluidic sustentation, and cable-based actuation system of a steerable tip for a multilumen flexible catheter is described; the hierarchical control system shared between the surgeon and the computer, and based on machine vision techniques and a simple but effective three-dimensional reconstruction is detailed. The Blind Expected Perception sensory-motor scheme is proposed in robot-assited endoscopy. Results from in vitro, ex vivo, and in vivo experiments show that the described model can accurately predict the shape of the catheter given the tension distribution on the cables, that the proposed actuation system can assure smooth and precise control of the catheter tip, that the fluidic sustentation of the catheter is essential in in vivo navigation, and that the proposed rear view mirror interface to show non-visible obstacles is appropriate; in conclusion, the results proved the validity of the proposed solution to develop an intrinsically safe robotic system for navigation and intervention in a narrow and challenging environment such as the spinal subarachnoid space.
Numerical modelling of the reinforcing effect of geosynthetic material used in ballasted railway tracks
Authors: Jiroušek O , Jíra J , Hrdlička O , Kunecký J , Kytýř D , Vyčichl J , Doktor T
Published: May 2010

This article deals with finite-element (FE) modelling of the reinforcing effect of the geosynthetic material used in the construction of a ballasted track. Various different designs of geosynthetic material are studied and their reinforcing effects are evaluated in terms of the total settlement reduction. Three-dimensional FE models of the reinforced railway superstructure are compared to a reference FE model with no reinforcement. Each geosynthetic material is modelled respecting its material properties, and the interaction with the ballast material is simulated according to its primary function. A clear distinction in the modelling of the interaction with the ballast material is made between geogrids and the remaining geosynthetics. A new approach to model the reinforcing effect of a geogrid is proposed and evaluated by FE analysis. The results of numerical modelling are compared to those of experiments conducted using an experimental box instrumented with one half of an instrumented concrete sleeper. Different types of geosynthetics were used to reinforce the ballast material, and the settlement reduction was measured using linear variable differential transformer (LVDT) sensors. The proposed FE models enable quick evaluation of the reinforcing effect of a given geosynthetic and comparison to other possible solutions in terms of the total settlement reduction. Other design possibilities (e.g. the use of reinforcing geosynthetics in several layers) are briefly discussed, too.
The Influence of Wheel Profile on the Safety Index
Authors: dos Santos G F M , Lopes L A S , Kina E J , Tunna J
Published: May 2010

Railways around the world are seen to use data from wayside detectors to drive vehicle maintenance strategies and to increase safety by finding and fixing the ‘bad actors’. VALE, one of these railway companies, has installed a truck performance detector and one wheel profile detector on the Estrada de Ferro Vitoría Minas (EFVM). Although it is well known that the wheel profile has a strong influence on vehicle dynamics, especially on safety parameters such as lateral over vertical forces at the wheel rail contact (L/V), each railway has its own particular vehicle-track interaction. On EFVM, wheel re-profiling is typically done because of thin flanges. This article shows the correlation between wheel profiles and safety performance predicted by modelling to find out the wheel profile limits that should be applied from the safety point of view. Wheel-rail contact theory and vehicle dynamics have been studied. L/V values and hunting speeds have been calculated. Many wheel profiles have been analysed. The results show that it is possible to set the limits used by wayside detectors to identify ‘bad actors’ and to increase the overall safety.
Modified one-dimensional analysis and two-zone modelling for predicting the performance of radial compressors
Authors: Karimi M , Hashemi E
Published: May 2010

Simulation of centrifugal compressors performance is widely performed by one-dimensional analysis because of relatively reliable results by this method, considering some major modifications in gas properties and analysing compression stages. The compressed medium is mixture of various gasses with different thermodynamic properties and molecular weights, which lead to considerable changes owing to different process and site conditions in many oil and gas applications. The mentioned characteristic changes are not considered in traditional performance prediction methods and result in large errors during estimation. In this paper, modified two-zone and one-dimensional models are presented, in which major variations are considered and numerical solutions are employed to successfully achieve satisfactory performance estimation. Results are verified with experimental data for stage pressure ratios and rotor efficiencies. These comparisons show that the proposed one-dimensional and two-zone models are revised in comparison to conventional techniques and effectively simulate compressors performance.
Two equivalent control structures for an electrohydraulic actuator
Authors: Ayalew B
Published: May 2010

Two non-linear control structures are considered for position control of an electrohydraulic actuator. The first control structure is derived from a direct near input-output (IO) linearization of the actuator model with position as output. The second control structure is a cascade of a near IO linearizing pressure force controller as an inner loop to a feedback plus feedforward outer-loop position controller. In the present paper, it is shown that the two control structures are theoretically equivalent. Then, it is highlighted that the equivalence can be exploited to extract a simple and intuitive tuning procedure for selecting the gains of one control structure from the gains of the other structure. This result is particularly useful for tuning the near IO linearizing position controller as the interpretation of its gains is obscured by the non-linear state transformation of the feedback linearization. Some numerical simulation and experimental results are included to demonstrate the identified tuning procedure.
Genetic adaptive state estimation with missing input/output data
Authors: Fang H , Wu J , Shi Y
Published: May 2010

This paper presents the application of a genetic algorithm to state estimation for systems subject to randomly missing input/output data. By modelling the missing data in inputs and outputs with binomial processes, a modified Luenberger observer using the reconstructed data is employed for estimation. The proposed algorithm consists of two procedures: 1) Preprocessing the missing input/output data by reconstruction based on autoregressive (AR) modelling; and 2) implementing the genetic algorithm to perform on-line adaptive state estimation from reconstructed data. The effectiveness of the proposed algorithm is verified by numerical simulation.
Exponential estimates and H∞ control for singular Markovian jump systems with interval time-varying delay
Authors: Lin J , Fei S , Shen J , Long F
Published: May 2010

This paper is concerned with exponential estimates and H∞ control for a class of singular Markovian jump systems with interval time-varying delay. By constructing an appropriate Lyapunov-Krasovskii functional and using some algebraic techniques, a sufficient condition, which does not only guarantee the regularity, absence of impulses, and mean square exponential stability but also gives the estimates of decay rate and decay coefficient, is derived in terms of linear matrix inequalities (LMIs). A bounded real lemma is also developed. Based on these, a state-feedback controller which makes the closed-loop system stochastically exponentially admissible with a guaranteed H∞ noise-attenuation performance and a prescribed lower bound of the decay rate is designed by employing the LMI technique. Numerical examples are provided to illustrate the effectiveness of the proposed design methods.
Robust H∞ control of time-varying systems with stochastic non-linearities: The finite-horizon case
Authors: Ma Lifeng , Wang Zidong , Bo Yuming , Guo Zhi
Published: May 2010

This paper is concerned with the robust H∞ control problem for the class of uncertain non-linear discrete time-varying stochastic systems with a covariance constraint. All the system parameters are time-varying and the uncertainties enter into the state matrix. The non-linearities under consideration are described by statistical means and they cover several classes of well-studied non-linearities. The purpose of the addressed problem is to design a dynamic output-feedback controller such that, the H∞ disturbance rejection attenuation level is achieved in the finite-horizon case while the state covariance is not more than an individual upper bound at each time point. An algorithm is developed to deal with the addressed problem by means of recursive linear matrix inequalities (RLMIs). It is shown that the robust H∞ control problem is solvable if the series of RLMIs is feasible. An illustrative simulation example is given to show the applicability and effectiveness of the proposed algorithm.
Nickel/Lewis Acid-Catalyzed Carbocyanation of Alkynes Using Acetonitrile and Substituted Acetonitriles
Authors: Yada Akira , Yukawa Tomoya , Idei Hiroaki , Nakao Yoshiaki , Hiyama Tamejiro
Published: May 2010

Nickel/Lewis acid dual catalysis is found to effect the carbocyanation reaction of alkynes using acetonitrile and substituted acetonitriles to give a range of variously substituted acrylonitriles. The addition of propionitrile across alkynes is also demonstrated briefly to give the corresponding ethylcyanation products in good yields, whereas the reaction of butyronitrile gives significant amounts of hydrocyanation products due possibly to β-hydride elimination of a propylnickel intermediate. The reaction of optically active α-phenylpropionitrile suggests a reaction mechanism that involves oxidative addition of a C–CN bond with retention of its absolute configuration.
Genome-wide analysis of N1-methyl-adenosine modification in human tRNAs
Authors: Saikia Mridusmita , Fu Ye , Pavon-Eternod Mariana , He Chuan , Pan Tao
Published: May 2010

The N1-methyl-Adenosine (m1A58) modification at the conserved nucleotide 58 in the TΨC loop is present in most eukaryotic tRNAs. In yeast, m1A58 modification is essential for viability because it is required for the stability of the initiator-tRNAMet. However, m1A58 modification is not required for the stability of several other tRNAs in yeast. This differential m1A58 response for different tRNA species raises the question of whether some tRNAs are hypomodified at A58 in normal cells, and how hypomodification at A58 may affect the stability and function of tRNA. Here, we apply a genomic approach to determine the presence of m1A58 hypomodified tRNAs in human cell lines and show how A58 hypomodification affects stability and involvement of tRNAs in translation. Our microarray-based method detects the presence of m1A58 hypomodified tRNA species on the basis of their permissiveness in primer extension. Among five human cell lines examined, approximately one-quarter of all tRNA species are hypomodified in varying amounts, and the pattern of the hypomodified tRNAs is quite similar. In all cases, no hypomodified initiator-tRNAMet is detected, consistent with the requirement of this modification in stabilizing this tRNA in human cells. siRNA knockdown of either subunit of the m1A58-methyltransferase results in a slow-growth phenotype, and a marked increase in the amount of m1A58 hypomodified tRNAs. Most m1A58 hypomodified tRNAs can associate with polysomes in varying extents. Our results show a distinct pattern for m1A58 hypomodification in human tRNAs, and are consistent with the notion that this modification fine tunes tRNA functions in different contexts.
Identification of novel ribonucleo-protein complexes from the brain-specific snoRNA MBII-52
Authors: Soeno Yuuichi , Taya Yuji , Stasyk Taras , Huber Lukas A. , Aoba Takaaki , Hüttenhofer Alexander
Published: May 2010

Small nucleolar RNAs (snoRNAs) guide nucleotide modifications within ribosomal RNAs or spliceosomal RNAs by base-pairing to complementary regions within their RNA targets. The brain-specific snoRNA MBII-52 lacks such a complementarity to rRNAs or snRNAs, but instead has been reported to target the serotonin receptor 2C pre-mRNA, thereby regulating pre-mRNA editing and/or alternative splicing. To understand how the MBII-52 snoRNA might be involved in these regulatory processes, we isolated the MBII-52 snoRNP from total mouse brain by an antisense RNA affinity purification approach. Surprisingly, by mass spectrometry we identified 17 novel candidates for MBII-52 snoRNA binding proteins, which previously had not been reported to be associated with canonical snoRNAs. Among these, Nucleolin and ELAVL1 proteins were confirmed to independently and directly interact with the MBII-52 snoRNA by coimmunoprecipitation. Our findings suggest that the MBII-52 snoRNA assembles into novel RNA-protein complexes, distinct from canonical snoRNPs.
The Nested Event Tree Model with Application to Combating Terrorism
Authors: Lunday Brian J. , Sherali Hanif D. , Glickman Theodore S.
Published: May 2010

In this paper, we model and solve the strategic problem of minimizing the expected loss inflicted by a hostile terrorist organization. An appropriate allocation of certain capability-related, intent-related, vulnerability-related, and consequence-related resources is used to reduce the probabilities of success in the respective attack-related actions and to ameliorate losses in case of a successful attack. We adopt a nested event tree optimization framework and formulate the problem as a specially structured nonconvex factorable program. We develop two branch-and-bound schemes based, respectively, on utilizing a convex nonlinear relaxation and a linear outer approximation, both of which are proven to converge to a global optimal solution. We also design an alternative direct mixed-integer programming model representation for this case, and we investigate a fundamental special-case variant for this scheme that provides a relaxation and affords an optimality gap measure. Several range reduction, partitioning, and branching strategies are proposed, and extensive computational results are presented to study the efficacy of different compositions of these algorithmic ingredients, including comparisons with the commercial software BARON. A sensitivity analysis is also conducted to explore the effect of certain key model parameters.
Decorous Lower Bounds for Minimum Linear Arrangement
Authors: Caprara Alberto , Letchford Adam N. , Salazar-González Juan-José
Published: May 2010

Minimum linear arrangement is a classical basic combinatorial optimization problem from the 1960s that turns out to be extremely challenging in practice. In particular, for most of its benchmark instances, even the order of magnitude of the optimal solution value is unknown, as testified by the surveys on the problem that contain tables in which the best-known solution value often has one more digit than the best-known lower bound value. In this paper, we propose a linear programming-based approach to compute lower bounds on the optimum. This allows us, for the first time, to show that the best-known solutions are indeed not far from optimal for most of the benchmark instances.
Sample-size effects on diet analysis from scats of jaguars and pumas
Authors: Foster Rebecca J. , Harmsen Bart J. , Doncaster C. Patrick
Published: May 2010

No abstract available
Diagnosis and localisation of insulinoma: the value of modern magnetic resonance imaging in conjunction with calcium stimulation catheterisation
Authors: Druce Maralyn R , Muthuppalaniappan Vasantha M , O'Leary Benjamin , Chew Shern L , Drake William M , Monson John P , Akker Scott A , Besser Michael , Sahdev Anju , Rockall Andrea , Vyas Soumil , Bhattacharya Satya , Matson Matthew , Berney Daniel , Grossman Ashley B
Published: May 2010

The authors apologise for an error in the author list of the article titled above published in the journal, volume 162 on page 971. R H Reznek should be the penultimate author. The full list of authors and their affiliations for this article is as follows:

Maralyn R Druce1, Vasantha M Muthuppalaniappan1, Benjamin O'Leary1, Shern L Chew1, William M Drake1, John P Monson1, Scott A Akker1, Michael Besser1, Anju Sahdev2, Andrea Rockall2, Soumil Vyas3, Satya Bhattacharya3, Matthew Matson2, Daniel Berney4, R H Reznek2 and Ashley B Grossman1

Departments of 1Endocrinology, 2Radiology, 3Surgery and 4Histopathology, Barts and the London Medical School, St Bartholomew's Hospital, London EC1A 7BE, UK.
The role of TSH for 18F-FDG-PET in the diagnosis of recurrence and metastases of differentiated thyroid carcinoma with elevated thyroglobulin and negative scan: a meta-analysis
Authors: Ma Chao , Xie Jiawei , Lou Yanhui , Gao Yanyan , Zuo Shuyao , Wang Xufu
Published: May 2010

Purpose

To establish the effects of TSH stimulation on the uptake of fluorine-18-labeled 2-fluoro-2-deoxy-d-glucose for differentiated thyroid carcinoma (DTC) with thyroglobulin-positive and scan negative metastases.

Materials and methods

We searched the MEDLINE, EMBASE and the Cochrane Library for prospective controlled trials using TSH stimulation as an intervention. The outcomes of positron emission tomography (PET)-positive lesions, tumor-to-background ratio, maximum standard uptake value of the detected lesions were extracted and synthesized, and patients with the altered clinical management were studied. A meta-analysis was carried out using the Review Manager software.

Results

Seven prospective controlled clinical trials with 168 patients were found. All studies had a low risk of bias. PET scans under TSH stimulation versus thyroid hormone suppression showed statistically significant differences in the number of patients with PET true-positive lesions (odds ratio (OR) 2.45, 95% confidence interval (CI) 1.23–4.90) and in the number of the PET-detected lesions (OR 4.92, 95% CI 2.70–8.95) and tumor-to-background ratios. PET scans taken under TSH stimulation altered clinical management in altogether 12/130 (9%) patients in five paired studies (OR 2.40, 95% CI 1.11–5.22).

Conclusion

The data indicate that TSH stimulation should be recommended for DTC patients undergoing PET scanning in these circumstances. However, further well-designed studies emphasizing on the clinical significance of altered management by PET under TSH stimulation are needed.
Engineering profession launches manifesto for the UK
Authors: Jowitt Paul
Published: May 2010

In the run up to the UK general election. ICE and seven other leading engineering organisations have published a manifesto to ensure all political parties grasp the importance of engineering to Britain's future economic development. ICE president Paul Jowitt reports.
Opportunities within change: looking beyond the immediate
Authors: Train Norman
Published: May 2010

Consulting engineer Norman Train became the 90th president of The Institution of Structural Engineers in January 2010. This is a summary of his inaugural address, in which he calls for civil and structural engineers to be more outward facing.
EU energy performance of buildings directive gets tough
Authors: Janssen Rod
Published: May 2010

A revised and much tougher version of the EU energy performance of buildings directive is due to enter into force this summer. Rod Janssen of the European Council for an Energy Efficient Economy says civil engineers can no longer afford to ignore it.
Climate variability in civil infrastructure planning
Authors: Mason Peter John
Published: May 2010

An understanding of climate variability – both man-made and natural – is vital in the planning of major water infrastructure and other civil engineering works. While there has been extensive modelling in recent years of mankind's potential effects on climate, studies of natural variability have not been given the same prominence. In the light of wider availability of climate data and an increased ability to process such data, this paper revisits the effects of natural variability. Using African examples it shows that clear natural cycles can be identified which, when combined with possible anthropomorphic effects, can provide civil engineers with far better long-term climate predictions.
The philosophy of engineering: a critical summary
Authors: Hillier Joseph
Published: May 2010

Over the past decade or so, a new form of engineering thinking has begun to emerge called the ‘philosophy of engineering’. As yet, very few civil engineers are aware of this growing field, but it could have important implications and benefits for them. This paper provides a brief, critical review of the philosophy of engineering, analysing relevant literature to highlight major arguments and looking where it might develop. The paper also describes a rift in the field and uses this to argue that the philosophy of engineering is relevant to all engineers and their status in society.
Redefining maritime transport infrastructure
Authors: Baird Alfred
Published: May 2010

Aided by investigation and analysis of European maritime policies and ongoing transport network developments, this paper redefines maritime transport infrastructure as the ships themselves rather than just the ports at each end. It argues that the seaway platform, namely the floating deck of a vessel, is comparable in a functional sense with road and rail infrastructure. This new interpretation could result in a more equitable approach to policy-making, public funding and user charging for maritime transport.
Pianc: 125 years of promoting waterborne transport
Authors: Van den Eede Eric
Published: May 2010

The World Association for Waterborne Transport Infrastructure – better known by its original acronym Pianc – celebrates its 125th anniversary in 2010, making it one of the world's oldest technical associations. It provides guidance for sustainable waterborne transport infrastructure for ports and waterways worldwide. This paper provides a brief overview of Pianc's history and accomplishments over the past one and a quarter centuries together with a review of its current roles and activities.
Change in microstructure of kaolin in consolidation and undrained shear
Authors: Bai X. , Smart R.
Published: May 2010

Changes of the microstructure of kaolin during undrained shear are reported. Digital image analysis of both optical and scanning electron micrographs was employed. The preferred orientation, which was originally horizontal, remained such during shear, until the failure plane cut through this laminar structure. The sample anisotropy was initially moderate, and it appeared to increase and later to decrease with strain. The difference in orientation of the individual structural elements seemed to decrease initially and later to increase, this being the complementary trend. The average sizes of all of the structual elements mapped in both types of microscope varied only slightly with strain. These results suggest a new hypothesis that the particles or domains tend to bed down into the horizontal during the early stages of shear, and then they tend to be disrupted slightly during later stages. However, in some samples the structural features identified by optical microscopy became slightly larger with strain increase, whereas in others they became smaller. Thus the effect of strain on microstructure was not the same for all the samples, which were originally similar. This suggests that there may be an element of instability in the microstructural response to strain.
The significance of the strain path analysis in the interpretation of piezocone dissipation data
Authors: Danziger F. A. B. , Almeida M. S. S. , Sills G. C.
Published: May 2010

When a piezocone is driven into the ground, pore water pressures are set up as a result of the stress changes. The dissipation of these pore pressures occurs in the subsequent con-solidation process in a manner dependent on the initial stress distribution as well as on the coefficient of consolidation. The process of analysis therefore has two distinct components. The first is to identify the appropriate total stress distribution caused by driving the piezocone, which acts as the initial condition for the consolidation. The second is to solve the consolidation problem itself. This approach has been followed by Levadoux & Baligh (1986, J. Geotech. Engng, ASCE 112, No. 7, 707–726), Baligh & Levadoux (1986, J. Geotech. Engng, ASCE 112, No. 7, 727–745) and by Houlsby & Teh (1988, Penetration testing 1988 (ed. J. de Ruiter), Balkema, Amsterdam, Vol. 2, pp. 777–783). Each of the two sets of authors uses the same consolidation theory for the second stage of the analysis, and a strain path method to identify the initial stress conditions. However, different assumptions about soil behaviour and the relevant soil parameters are made in carrying out the strain path analyses. A real situation will differ from the theoretical one both by differences from the model assumed, and in the choice of numerical values of the relevant parameters. For the two approaches to the piezocone analysis. Houlsby & Teh (1988) used an elastic-plastic model, in which the value of the rigidity index, G/su, may be specified in the analysis, while Levadoux & Baligh's solution, with a similar theoretical basis, used parameters specifically appropriate for Boston Blue Clay. This paper discusses the question of an appropriate choice of numerical values of the soil parameters and reports a comparison between the two theoretical predictions and field measurements from two different piezocones deployed in Sarapui soft clay, Brazil. The values of the coefficient of consolidation ch calculated from the field data by the two methods are then compared with high quality laboratory tests on the Sarapui clay. It is shown that both theoretical predictions provide good agreement for the shape of the dissipation curve, but that the predicted ch values are different, and that thought should indeed be given to the use of an appropriate value of G/su.