bluuebunny/crossref_metadata_2025 huggingface dataset:
Emergence of chondrogenic progenitor stem cells in transplantation biology—prospects and drawbacks
Authors: Mathur Deepali , Pereira Winston Costa , Anand Akshay
Published: September 2011

Avascular tissues such as a cartilage contains a unique type of cell called as the chondrocyte. We, however, have not understood the origin of the chondrocyte population and how this population is maintained in the normal tissue. In spite of being considered to be a simple tissue, scientist had always faced difficulties to engineer this tissue. This is because different structural regions of the articular cartilage were never understood. In addition to this, the limited self‐repair potential of cartilage tissue and lack of effective therapeutic options for the treatment of damaged cartilage has remained an unsolved problem. Mesenchymal stem cell based therapy may provide a solution for cartilage regeneration. This is due to their ability to differentiate into chondrogenic lineage when appropriate conditions are provided. An ideal cell source, a three‐dimensional cell culture, a suitable scaffold material that accomplishes all the necessary properties and bioactive factors in specific amounts are required to induce chondrocyte differentiation and proliferation. Cartilage tissue engineering is a promising and rapidly expanding area of research that assures cartilage regeneration. However, many unsolved questions concerning the mechanism of engraftment of chondrocytes following transplantation in vivo, biological safety after transplantation and the retention of these cells for lifetime remain to be addressed that is possible only through years of extensive research. Further studies are therefore required to estimate the long‐term sustainability of these cells in the native tissue, to identify well suited delivery materials and to have a thorough understanding of the mechanism of interaction between the chondrocytes and extracellular matrix and time is not far when this cell based therapy will provide a comprehensive cure to cartilage disease. J. Cell. Biochem. 113: 397–403, 2012. © 2011 Wiley Periodicals, Inc.
A role of Rab7 in stabilizing EGFR‐Her2 and in sustaining Akt survival signal
Authors: Wang Tuanlao , Zhang Ming , Ma Zexu , Guo Ke , Tergaonkar Vinay , Zeng Qi , Hong Wanjin
Published: September 2011

Rab7 plays an important role in regulating endocytic traffic. In view of an emerging role of membrane traffic in signaling and diseases, we have examined the possible role of Rab7 in oncogenesis. The role of Rab7 was investigated using shRNA‐mediated knockdown in A431 and MCF7 cancer cells. To our surprise, Rab7 knockdown effectively suppressed anchorage‐independent growth of cancer cells in soft agar. Anoikis (matrix‐detachment triggered apoptosis) was enhanced, while the level of phosphorylated (active) Akt (which is a key survival factor) was significantly reduced. Also intriguing was the observation that EGFR and Her2 levels were significantly reduced when Rab7 was knocked‐down. More robust reduction of EGFR and Her2 levels was observed when knocked‐down cells were treated with HSP90 inhibitor geldanamycin (GA). Low concentration of GA (50–100 nm)‐induced apoptosis of the Rab7 knocked‐down cells but not control cells, suggesting that Rab7 and HSP90 together contribute to the optimal stability of EGFR and Her2 as well as to protect cancer cells from apoptosis. Rab7 seems to protect EGFR and Her2 from proteosome‐mediated degradation. These results suggest that Rab7 is likely involved in protecting EGFR and Her2 from being degraded by the proteosome and in maintaining optimal Akt survival signal (especially during cell detachment or when HSP90 is inhibited). Rab7 is potentially a novel target for combinatory therapy with Hsp90 inhibitors. J. Cell. Physiol. 227: 2788–2797, 2012. © 2011 Wiley Periodicals, Inc.
Synthesis and characterization of electroactive epoxy‐based interpenetrating polymer network gel
Authors: Kanai Tapan , Pandey Kusum , Samui A. B.
Published: September 2011

Epoxy/poly(N‐isopropylacrylamide) interpenetrating polymer network gels were prepared by varying the excess amine content in the matrix (0.4–0.6 equivalent). All the samples were characterized for mechanical properties and swelling in distilled water. The topography of polymer network was characterized by atomic force microscopy. The 0.5 equiv. excess amine sample exhibited optimum properties. Studies on swelling at different pH and electroactivity in different aqueous solution were performed. The bending angle observed during first 1 min was 1–5° at 3–10 V and a maximum of 25° in 5 min at 20 V for 0.5 equiv. excess amine in NaCl solution. Copyright © 2011 John Wiley & Sons, Ltd.
Threaded behavior protocols
Authors: Poch Tomáš , Šerý Ondřej , Plášil František , Kofroň Jan
Published: September 2011

Component-based development is a well-established methodology of software development. Nevertheless, some of the benefits that the component based development offers are often neglected. One of them is modeling and subsequent analysis of component behavior, which can help establish correctness guarantees, such as absence of composition errors and safety of component updates. We believe that application of component behavior modeling in practice is limited due to huge differences between the behavior modeling languages (e.g., process algebras) and the common implementation languages (e.g., Java). As a result, many concepts of the implementation languages are either very different or completely missing in the behavior modeling languages. As an example, even though behavior modeling languages are practical for modeling and analysis of various message-based protocols, they are not well suited for modeling current component applications, where thread-based parallelism, lock-based synchronization, and nested method calls are the essential building blocks. With this in mind, we propose a new behavior modeling language for software components, Threaded Behavior Protocols (TBP). At the model level, TBP provides developers with the concepts known from the implementation languages and essential to most component applications. In addition, the theoretical framework of TBP provides a notion of correctness based on absence of communication errors and a refinement relation to verify correctness of hierarchical components. The main asset of TBP formalism is that it links together the notion of threads as used in imperative object oriented languages and the notion of refinement. For instance, this allows reasoning about hierarchical components composed of primitive components implemented in Java without the need of bridging abstractions and simplifications enforced by the modeling languages.
Study of the SN2 Substitution Reactions Between Methyl Naphtalene‐2‐Sulfonate and Methyl 4‐Nitrobenzene Sulfonate and Bromide Ions in Dodecyl Dibromide Dimeric Micellar Solutions in the Absence and Presence of Alcohols
Authors: del Mar Graciani María , Rodríguez Amalia , Martín Victoria Isabel , Moyá María Luisa
Published: September 2011

The SN2 substitution reactions between methyl naphthalene‐2‐sulfonate and methyl 4‐nitrobenzenesulfonate with bromide ions were studied in alkanediyl‐α,ω‐bis(dimethyldodecylammonium) bromide, 12‐s‐12,2Br− (s = 3, 4, 6), micellar solutions in the absence and in the presence of alcohols. The observed rate constant for the two processes was found to be sensitive to changes in micellar characteristics caused by the presence of alcohols. At high surfactant concentrations, kinetic data made evident the sphere‐to‐rod transition accompanying the increase in the dimeric surfactant concentration in all the micellar reaction media investigated. Kinetic results were quantitatively rationalized within the whole surfactant concentration range, below and above the second CMC, by using a new treatment based on the pseudophase kinetic model.
Developmental dysplasia of the hip: Impact of sonographic newborn hip screening on the outcome of early treated decentered hip joints—a single center retrospective comparative cohort study based on Graf's method of hip ultrasonography
Authors: Tschauner Christian , Fürntrath Frank , Saba Yasaman , Berghold Andrea , Radl Roman
Published: September 2011

Purpose/Background/Introduction

The aim of this study was to retrospectively evaluate the impact of neonatal sonographic hip screening using Graf's method for the management and outcome of orthopaedic treatment of decentered hip joints with developmental dysplasia of the hip (DDH), using three decades (1978–2007) of clinical information compiled in a medical database.

Methods

Three representative cohorts of consecutive cases of decentered hip joints were selected according to different search criteria and inclusion and exclusion parameters: (1) cohort 1 (1978–1982; n = 80), without sonographic screening; (2) cohort 2.1 (1994–1996; n = 91), with nationwide established general sonographic screening according to the Graf-method; (3) cohort 2.2 (2003–2005; n = 91), with sonographic screening including referred cases for open reduction from non-screened populations. These three cohorts were compared for the following parameters: age at initial treatment, successful closed reduction, necessary overhead traction, necessary adductor-tenotomy, rate of open reduction, rate of avascular necrosis (AVN) and rate of secondary acetabuloplasty.

Results

The age at initial treatment was reduced from 5.5 months in the first cohort to 2 months in the two subsequent two cohorts and the rate of successful closed reduction increased from 88.7 to 98.9 and 95.6%, respectively. There was a statistically significant improvement in six out of seven parameters with sonographic hip screening; only the rate of secondary acetabuloplasty did not improve significantly.

Conclusion

Compared to the era before the institution of a sonographic hip screening programme according to the Graf-method in Austria in 1992, ultrasound screening based-treatment of decentered hip joints has become safer, shorter and simpler: “safer” means lower rate of AVN, “shorter” means less treatment time due to earlier onset and “simpler” means that the devices are now less invasive and highly standardized.
Resistance to regulatory T cell-mediated suppression in rheumatoid arthritis can be bypassed by ectopic foxp3 expression in pathogenic synovial T cells
Authors: Beavis Paul A. , Gregory Bernard , Green Patricia , Cribbs Adam P. , Kennedy Alan , Amjadi Parisa , Palfreeman Andrew C. , Feldmann Marc , Brennan Fionula M.
Published: September 2011

Increasing evidence suggests that regulatory T cell (Treg) function is impaired in chronic inflammatory diseases such as rheumatoid arthritis (RA). Here we demonstrate that Tregs are unable to modulate the spontaneous production of TNF-α from RA synovial cells cultured from the diseased synovium site. Cytokine (IL-2, IL-6, TNF-α) activated T cells (Tck), cells we previously demonstrated to mimic the effector function of pathogenic RA synovial T cells, contained Tregs that survived and divided in this cytokine environment; however, the up-regulation of key molecules associated with Treg function (CTLA-4 and LFA-1) was impaired. Furthermore, Tregs were unable to suppress the function of Tcks, including contact-dependent induction of TNF-α from macrophages, supporting the concept that impaired Treg function/responsiveness contributes to chronicity of RA. However, ectopic foxp3 expression in both Tcks and pathogenic RA synovial T cells attenuated their cytokine production and function, including contact-dependent activation of macrophages. This diminished response to cytokine activation after ectopic foxp3 expression involved inhibited NF-κB activity and differed mechanistically from that displayed endogenously in conventional Tregs. These results suggest that diseases such as RA may perpetuate owing to the inability of Tregs to control cytokine-activated T-cell function. Understanding the mechanism whereby foxp3 attenuates the pathogenic function of synovial T cells may provide insight into the mechanisms of chronicity in inflammatory disease and potentially reveal new therapeutic candidates.
The Mediatory Guile of the Nanny in Persian Romance
Authors: Milani Farzaneh
Published: September 2011

The Word for Guile (Kayd) Itself Seems to be Shifty. Sometimes it is positive, sometimes negative, at times divine. It seems to assume its significance from its context. It becomes positive or negative according to the point of view of the one who uses it. It has a variety of meanings: Steingass's listing “deceiving, laying snares, entrapping, plotting mischief; applying a remedy, vomiting; being menstruous; the croak of a raven; war, warfare; deceit, fraud, stratagem; treachery, malignity, malice” illustrates its large semantic field. Kayd can also be a divine attribute. In the Qur˒anic chapter in which the Egyptian ruler admonishes his wife and utters the often repeated verse 29, “Indeed your guile is great,” verse 76 links kayd with God who “did devise a plan for Joseph.” “There are at least thirty-four uses of the Arabic root K.Y.D in the Qur˒an, and a number of them refer to God's action.”

Some of the most admired heroes and heroines of Persian literature are guileful. Most writers, however, have formulated their paradigms of guile with women in mind. Kayd and its numerous synonyms, although not gendered words, are frequently “feminized.”
Fast-ion effects during test blanket module simulation experiments in DIII-D
Authors: Kramer G.J. , Budny B.V. , Ellis R. , Gorelenkova M. , Heidbrink W.W. , Kurki-Suonio T. , Nazikian R. , Salmi A. , Schaffer M.J. , Shinohara K. , Snipes J.A. , Spong D.A. , Koskela T. , Van Zeeland M.A.
Published: September 2011

Fast beam-ion losses were studied in DIII-D in the presence of a scaled mock-up of two test blanket modules (TBM) for ITER. Heating of the protective tiles on the front of the TBM surface was found when neutral beams were injected and the TBM fields were engaged. The fast-ion core confinement was not significantly affected. Different orbit-following codes predict the formation of a hot spot on the TBM surface arising from beam ions deposited near the edge of the plasma. The codes are in good agreement with each other on the total power deposited at the hot spot, predicting an increase in power with decreasing separation between the plasma edge and the TBM surface. A thermal analysis of the heat flow through the tiles shows that the simulated power can account for the measured tile temperature rise. The thermal analysis, however, is very sensitive to the details of the localization of the hot spot, which is predicted to be different among the various codes.
Integrated simulation of ELM triggered by a pellet through energy absorption and transport enhancement
Authors: Hayashi N. , Parail V. , Koechl F. , Aiba N. , Takizuka T. , Wiesen S. , Lang P.T. , Oyama N. , Ozeki T.
Published: September 2011

Two integrated core/scrape-off layer/divertor transport codes TOPICS-IB and JINTRAC with links to MHD stability codes are coupled with models of pellet injection to clarify effects of the pellet on the behaviour of edge-localized modes (ELMs). Both codes predict the following two triggering mechanisms. Energy absorption by the pellet and its further displacement due to the E × B drift, as well as transport enhancement by the pellet, are found to be able to trigger the ELM. The ablated cloud of pellet absorbs the background plasma energy and causes a radial redistribution of pressure due to the subsequent E × B drift. Further, the sharp increase in local density and temperature gradients in the vicinity of ablated cloud causes the transient enhancement of heat and particle transport. Both mechanisms produce a region of increased pressure gradient in the background plasma profile within the pedestal, which triggers the ELM. The mechanisms have the potential to explain a wide range of experimental observations.
Comparison between dominant NB and dominant IC heated ELMy H-mode discharges in JET
Authors: Versloot T.W. , Sartori R. , Rimini F. , de Vries P.C. , Saibene G. , Parail V. , Beurskens M.N.A. , Boboc A. , Budny R. , Crombé K. , de la Luna E. , Durodie F. , Eich T. , Giroud C. , Kiptily V. , Johnson T. , Mantica P. , Mayoral M.-L. , McDonald D.C. , Monakhov I. , Nave M.F.F. , Voitsekhovitch I. , Zastrow K.-D.
Published: September 2011

The experiment described in this paper is aimed at characterization of ELMy H-mode discharges with varying momentum input, rotation, power deposition profiles and ion to electron heating ratio obtained by varying the proportion between ion cyclotron (IC) and neutral beam (NB) heating. The motivation for the experiment was to verify if the basic confinement and transport properties of the baseline ITER H-mode are robust to these changes, and similar to those derived mostly from dominant NB heated H-modes. No significant difference in the density and temperature profiles or in the global confinement were found. Although ion temperature profiles were seen to be globally stiff, some variation of stiffness was obtained in the experiment by varying the deposition profiles, but not one that could significantly affect the profiles in terms of global confinement. This analysis shows the thermal plasma energy confinement enhancement factor to be independent of the heating mix, for the range of conditions explored. Moreover, the response of the global confinement to changes in density and power were also independent of heating mix, reflecting the changes in the pedestal, which is in agreement with globally stiff profiles. Consistently, the pedestal characteristics (pressure and width) and their dependences on global parameters such as density and power were the same during NB only or with predominant IC heating.
Simulations of combined neutral beam injection and ion cyclotron heating with the TORIC-SSFPQL package
Authors: Bilato R. , Brambilla M. , Maj O. , Horton L.D. , Maggi C.F. , Stober J.
Published: September 2011

A source describing the injection of fast ions due to the ionization of high-energy neutral beams has been added to the surface-averaged quasilinear Fokker–Planck code SSFPQL (Brambilla 1994 Nucl. Fusion
34 1121). For this purpose, the multiple-beam NBI code SINBAD (Feng et al 1995 Comput. Phys. Commun.
88 161) has been included as a module in SSFPQL, with the modifications required to handle arbitrary axisymmetric equilibria. Alternatively, the neutral beam injection (NBI) source can be built using the output of a Monte Carlo NBI code. We have also added a term describing losses of fast ions during thermalization, and a subroutine evaluating the neutron production rate by nuclear reactions. With these extensions, iterations between SSFPQL and the full-wave solver TORIC (Brambilla 1999 Plasma Phys. Control. Fusion
41 1) can now be used to investigate the strong interplay between NBI and ion cyclotron (IC) heating.

By comparing the predicted and measured neutron production rates from D–D reactions in a discharge with combined NBI and IC heating in ASDEX Upgrade we obtain a plausible estimate of the importance of fast-ion losses (FILs), even if their cause cannot be identified. We find, however, that the plasma composition, in particular the presence of low Z impurities, plays a more critical role than FILs in limiting the efficiency of this heating scheme.
Influence of trapped electrons on ECCD in Heliotron J
Authors: Nagasaki K. , Yamamoto S. , Yoshino H. , Sakamoto K. , Marushchenko N.B. , Turkin Y. , Mizuuchi T. , Okada H. , Hanatani K. , Minami T. , Masuda K. , Kobayashi S. , Konoshima S. , Takeuchi M. , Nakamura Y. , Ohshima S. , Mukai K. , Lee H.Y. , Mizuno K. , Yoshimura Y. , Motojima G. , Cappa Á. , Blackwell B.D. , Sano F.
Published: September 2011

Second-harmonic electron cyclotron current drive (ECCD) experiments have been performed in the stellarator/heliotron (S/H) device, Heliotron J. A focused Gaussian beam is injected with the parallel refractive index, N
∥, ranging from −0.05 to 0.6. The EC driven current is estimated by excluding the bootstrap current from the total current. The experimental results show that the EC driven current is determined by the local magnetic field structure where the EC power is deposited. The maximum EC driven current is attained around N
∥ = 0.5 when the EC power is deposited at nearly the top of the magnetic ripple. A large increase in electron cyclotron emission (ECE) signals is observed when the EC current is driven, indicating an important role for high-energy electrons in the ECCD. The experimental results for N
∥ and B dependence agree with a ray-tracing simulation using a parallel momentum conservation model in which the trapped particle effect is included.
A fusion-driven subcritical system concept based on viable technologies
Authors: Wu Y. , Jiang J. , Wang M. , Jin M.
Published: September 2011

A fusion-driven hybrid subcritical system (FDS) concept has been designed and proposed as spent fuel burner based on viable technologies. The plasma fusion driver can be designed based on relatively easily achieved plasma parameters extrapolated from the successful operation of existing fusion experimental devices such as the EAST tokamak in China and other tokamaks in the world, and the subcritical fission blanket can be designed based on the well-developed technologies of fission power plants. The simulation calculations and performance analyses of plasma physics, neutronics, thermal-hydraulics, thermomechanics and safety have shown that the proposed concept can meet the requirements of tritium self-sufficiency and sufficient energy gain as well as effective burning of nuclear waste from fission power plants and efficient breeding of nuclear fuel to feed fission power plants.
Bambus 2: scaffolding metagenomes
Authors: Koren Sergey , Treangen Todd J. , Pop Mihai
Published: September 2011

Motivation: Sequencing projects increasingly target samples from non-clonal sources. In particular, metagenomics has enabled scientists to begin to characterize the structure of microbial communities. The software tools developed for assembling and analyzing sequencing data for clonal organisms are, however, unable to adequately process data derived from non-clonal sources.

Results: We present a new scaffolder, Bambus 2, to address some of the challenges encountered when analyzing metagenomes. Our approach relies on a combination of a novel method for detecting genomic repeats and algorithms that analyze assembly graphs to identify biologically meaningful genomic variants. We compare our software to current assemblers using simulated and real data. We demonstrate that the repeat detection algorithms have higher sensitivity than current approaches without sacrificing specificity. In metagenomic datasets, the scaffolder avoids false joins between distantly related organisms while obtaining long-range contiguity. Bambus 2 represents a first step toward automated metagenomic assembly.

Availability: Bambus 2 is open source and available from http://amos.sf.net.

Contact:  mpop@umiacs.umd.edu

Supplementary Information:  Supplementary data are available at Bioinformatics online.
An efficient network querying method based on conditional random fields
Authors: Huang Qiang , Wu Ling-Yun , Zhang Xiang-Sun
Published: September 2011

Motivation: A large amount of biomolecular network data for multiple species have been generated by high-throughput experimental techniques, including undirected and directed networks such as protein–protein interaction networks, gene regulatory networks and metabolic networks. There are many conserved functionally similar modules and pathways among multiple biomolecular networks in different species; therefore, it is important to analyze the similarity between the biomolecular networks. Network querying approaches aim at efficiently discovering the similar subnetworks among different species. However, many existing methods only partially solve this problem.

Results: In this article, a novel approach for network querying problem based on conditional random fields (CRFs) model is presented, which can handle both undirected and directed networks, acyclic and cyclic networks and any number of insertions/deletions. The CRF method is fast and can query pathways in a large network in seconds using a PC. To evaluate the CRF method, extensive computational experiments are conducted on the simulated and real data, and the results are compared with the existing network querying methods. All results show that the CRF method is very useful and efficient to find the conserved functionally similar modules and pathways in multiple biomolecular networks.

Availability: Code and data are available at http://doc.aporc.org/wiki/CNetQ

Contact:  lywu@amt.ac.cn

Supplementary Information:  Supplementary data are available at Bioinformatics online.
Discovering relational-based association rules with multiple minimum supports on microarray datasets
Authors: Liu Yu-Cheng , Cheng Chun-Pei , Tseng Vincent S.
Published: September 2011

Motivation: Association rule analysis methods are important techniques applied to gene expression data for finding expression relationships between genes. However, previous methods implicitly assume that all genes have similar importance, or they ignore the individual importance of each gene. The relation intensity between any two items has never been taken into consideration. Therefore, we proposed a technique named REMMAR (RElational-based Multiple Minimum supports Association Rules) algorithm to tackle this problem. This method adjusts the minimum relation support (MRS) for each gene pair depending on the regulatory relation intensity to discover more important association rules with stronger biological meaning.

Results: In the actual case study of this research, REMMAR utilized the shortest distance between any two genes in the Saccharomyces cerevisiae gene regulatory network (GRN) as the relation intensity to discover the association rules from two S.cerevisiae gene expression datasets. Under experimental evaluation, REMMAR can generate more rules with stronger relation intensity, and filter out rules without biological meaning in the protein–protein interaction network (PPIN). Furthermore, the proposed method has a higher precision (100%) than the precision of reference Apriori method (87.5%) for the discovered rules use a literature survey. Therefore, the proposed REMMAR algorithm can discover stronger association rules in biological relationships dissimilated by traditional methods to assist biologists in complicated genetic exploration.

Availability: The source code in Java and other materials used in this study are available at http://websystem.csie.ncku.edu.tw/REMMAR_Program.rar

Contact:  tsengsm@mail.ncku.edu.tw

Supplementary Information:  Supplementary data are available at Bioinformatics online.
Influence of renal dysfunction phenotype on mortality in the setting of cardiac dysfunction: analysis of three randomized controlled trials
Authors: Testani Jeffrey M. , Coca Steven G. , Shannon Richard P. , Kimmel Stephen E. , Cappola Thomas P.
Published: September 2011

Aims

Renal neurohormonal activation leading to a reduction in glomerular filtration rate (GFR) has been suggested as a mechanism for renal insufficiency (RI) in the setting of heart failure. We hypothesized that RI occurring in the presence of renal neurohormonal activation may be prognostically more important than RI in the absence of renal neurohormonal activation.

Methods and results

Subjects in the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) trial (n = 429), Beta‐Blocker Evaluation of Survival Trial (BEST) (n = 2691), and Studies Of Left Ventricular Dysfunction (SOLVD) trial (n = 6782) limited datasets were studied. The blood urea nitrogen to creatinine ratio (BUN/Creatinine) was employed as a surrogate for renal neurohormonal activation and the primary outcome was the interaction between BUN/Creatinine and RI associated mortality. Baseline RI (GFR < 60 mL/min/1.73 m²) was associated with mortality in all study populations (P < 0.001). In patients with higher BUN/Creatinine, the risk of mortality was consistently greater in patients with RI [adjusted hazard ratio (HR) ESCAPE = 2.8, 95% confidence interval (CI) 1.3–14.3, P = 0.019; BEST = 1.6, 95% CI 1.2–2.2, P = 0.002; SOLVD = 1.6, 95% CI 1.3–2.0, P = 0.001]. However, in patients with lower BUN/Creatinine, the risk of mortality was not elevated in patients with RI (adjusted HR ESCAPE = 0.94, 95% CI 0.35–2.4, P = 0.90, P interaction = 0.005; BEST = 0.97, 95% CI 0.64–1.4, P = 0.90, P interaction = 0.02; SOLVD = 1.0, 95% CI 0.8–1.3, P = 0.71, P interaction = 0.005).

Conclusion

The association between RI and poor survival observed in heart failure populations appears to be contingent not simply on the presence of a reduced GFR, but possibly on the mechanism by which GFR is reduced.
Analysis of match–mismatch between commercial fishing periods and spawning ecology of Pacific halibut (Hippoglossus stenolepis), based on winter surveys and behavioural data from electronic archival tags
Authors: Loher Timothy
Published: September 2011

Loher, T. 2011. Analysis of match–mismatch between commercial fishing periods and spawning ecology of Pacific halibut (Hippoglossus stenolepis), based on winter surveys and behavioural data from electronic archival tags. – ICES Journal of Marine Science, 68: 2240–2251. The fishery for halibut (Hippoglossus stenolepis) in the eastern Pacific is closed during the boreal winter, roughly corresponding to the seasonal spawning of the species. Opening and closing dates for each season are stipulated annually based on economics and biology. Historical surveys and data from electronic tags are analysed to assess the extent to which recent closures have encompassed the annual spawning cycle of the species, as defined by migration to offshore spawning sites, active spawning, and return to feeding areas. These were assessed by calculating mean maximum daily depth profiles for fish exhibiting seasonal migration, calculating the date-specific proportions of the tagged population either migrating to or resident on their feeding or spawning grounds, and examining the temporal distribution of spent and running fish in historical surveys along with evidence of spawning contained in high-resolution tag data. The data indicate that fishery closures over the past 20 years have been consistently too short to protect the entirety of a migration period that begins as early as September and is not substantially completed until May. Additionally, some recent season openings have encroached on the active spawning season. Failure to fully protect spawning migrations may allow seasonal interception fisheries, and the selective removal of early and late spawners could cause changes in stock demographics, restrict effective spawning, and influence long-term stock productivity, especially in the face of environmental variability.
Connecting Micro- and Macropartisanship
Authors: Jackson John E. , Kollman Ken
Published: September 2011

This paper extends models of micro- and macropartisanship in two ways. It first develops a model of individual partisanship that accommodates changes in partisan utilities. Achen's Bayesian partisan updating is a special case of our model. This more general micromodel is then aggregated to create a model of macropartisanship. This macromodel is a more general version of the models of macropartisanship estimated by various authors. The less restricted version incorporates possible individual and temporal heterogeneity. We present an example using real data that offers a possible way to estimate the parameters in the full aggregate model.
WOX4 Imparts Auxin Responsiveness to Cambium Cells in Arabidopsis
Authors: Suer Stefanie , Agusti Javier , Sanchez Pablo , Schwarz Martina , Greb Thomas
Published: September 2011

Multipotent stem cell populations, the meristems, are fundamental for the indeterminate growth of plant bodies. One of these meristems, the cambium, is responsible for extended root and stem thickening. Strikingly, although the pivotal role of the plant hormone auxin in promoting cambium activity has been known for decades, the molecular basis of auxin responsiveness on the level of cambium cells has so far been elusive. Here, we reveal that auxin-dependent cambium stimulation requires the homeobox transcription factor WOX4. In Arabidopsis thaliana inflorescence stems, 1-N-naphthylphthalamic acid–induced auxin accumulation stimulates cambium activity in the wild type but not in wox4 mutants, although basal cambium activity is not abolished. This conclusion is confirmed by the analysis of cellular markers and genome-wide transcriptional profiling, which revealed only a small overlap between WOX4-dependent and cambium-specific genes. Furthermore, the receptor-like kinase PXY is required for a stable auxin-dependent increase in WOX4 mRNA abundance and the stimulation of cambium activity, suggesting a concerted role of PXY and WOX4 in auxin-dependent cambium stimulation. Thus, in spite of large anatomical differences, our findings uncover parallels between the regulation of lateral and apical plant meristems by demonstrating the requirement for a WOX family member for auxin-dependent regulation of lateral plant growth.
Nicotiana attenuata LECTIN RECEPTOR KINASE1 Suppresses the Insect-Mediated Inhibition of Induced Defense Responses during Manduca sexta Herbivory
Authors: Gilardoni Paola A. , Hettenhausen Christian , Baldwin Ian T. , Bonaventure Gustavo
Published: September 2011

Nicotiana attenuata has the capacity to respond specifically to herbivory by its natural herbivore, Manduca sexta, through the perception of elicitors in larval oral secretions. We demonstrate that Lectin receptor kinase 1 (LecRK1) functions during M. sexta herbivory to suppress the insect-mediated inhibition of jasmonic acid (JA)–induced defense responses. Gene function analysis performed by reducing LecRK1 expression in N. attenuata by both virus-induced gene silencing and inverted repeated RNA interference (ir-lecRK1 plants) revealed that LecRK1 was essential to mount a full defense response against M. sexta folivory; larvae growing on ir-lecRK1 plants were 40 to 100% larger than those growing on wild-type plants. The insect-induced accumulation of nicotine, diterpene-glucosides, and trypsin protease inhibitors, as well as the expression of Thr deaminase, was severalfold reduced in ir-lecRK1 plants compared with the wild type. The accumulation of JA and JA-Ile was unaffected during herbivory in ir-lecRK1 plants; however, salicylic acid (SA) accumulation was increased by twofold. The expression of nahG in ir-lecRK1 plants prevented the increased accumulation of SA and restored the defense response against M. sexta herbivory. The results suggest that LecRK1 inhibits the accumulation of SA during herbivory, although other mechanisms may also be affected.
The Transcription Factor ABI4 Is Required for the Ascorbic Acid–Dependent Regulation of Growth and Regulation of Jasmonate-Dependent Defense Signaling Pathways inArabidopsis
Authors: Kerchev Pavel I. , Pellny Till K. , Vivancos Pedro Diaz , Kiddle Guy , Hedden Peter , Driscoll Simon , Vanacker Hélène , Verrier Paul , Hancock Robert D. , Foyer Christine H.
Published: September 2011

Cellular redox homeostasis is a hub for signal integration. Interactions between redox metabolism and the ABSCISIC ACID-INSENSITIVE-4 (ABI4) transcription factor were characterized in the Arabidopsis thaliana  vitamin c defective1 (vtc1) and vtc2 mutants, which are defective in ascorbic acid synthesis and show a slow growth phenotype together with enhanced abscisic acid (ABA) levels relative to the wild type (Columbia-0). The 75% decrease in the leaf ascorbate pool in the vtc2 mutants was not sufficient to adversely affect GA metabolism. The transcriptome signatures of the abi4, vtc1, and vtc2 mutants showed significant overlap, with a large number of transcription factors or signaling components similarly repressed or induced. Moreover, lincomycin-dependent changes in LIGHT HARVESTING CHLOROPHYLL A/B BINDING PROTEIN 1.1 expression were comparable in these mutants, suggesting overlapping participation in chloroplast to nucleus signaling. The slow growth phenotype of vtc2 was absent in the abi4 vtc2 double mutant, as was the sugar-insensitive phenotype of the abi4 mutant. Octadecanoid derivative-responsive AP2/ERF-domain transcription factor 47 (ORA47) and AP3 (an ABI5 binding factor) transcripts were enhanced in vtc2 but repressed in abi4 vtc2, suggesting that ABI4 and ascorbate modulate growth and defense gene expression through jasmonate signaling. We conclude that low ascorbate triggers ABA- and jasmonate-dependent signaling pathways that together regulate growth through ABI4. Moreover, cellular redox homeostasis exerts a strong influence on sugar-dependent growth regulation.
Study of external air flow for an AURORA
Authors: Ribeiro Alves , Mantha Vishveshwar R. , Rouboa Abel I. , Marinho Daniel A. , Silva António J.
Published: September 2011

Purpose

The purpose of this current study is to identify the optimal stable position of airship, with reference to spatial variation of atmospheric wind flow, so as to reduce the vibrations and thus aid in the development of control mechanism of airship dynamics.

Design/methodology/approach

Study of uniform flow under steady‐state conditions was carried out through the measurements of pressure and velocity in a wind tunnel at low Mach numbers on airship model (in order of size, 1:13) inclined to the uniform air stream at various angles. The measurements have been made for a range of angles of incidence, in both vertical and horizontal planes, with a Reynolds number, based on the free stream velocity and a body cross‐sectional dimension, of order of four and six, respectively. Steady‐state numerical simulations were performed, serving comparative investigation with experimental data for the specific case of the model inclined to the free stream, with orientation of side‐slip (yaw) angle β=0 and angle of attack (pitch) α=0.

Findings

The numerical results showed similar trend as found by experimental analysis. In this study, several factors such as the pressure (Cp), lift (CL), drag (CD) coefficients, pressure and air velocity were taken into account for comparative analysis. The analysis paved the way in identification of constructively stable position of airship model with orientation of β=0 and α=0, with respect to air flow direction.

Practical implications

The current findings aid in the development of control mechanism of airship dynamics.

Originality/value

The experimental analysis of the airship model is presented along with computational fluid dynamics analysis of optimised shape of airship model in different orientations with respect to direction of airflow.
Effective fault diagnosis based on strong tracking UKF
Authors: Han Pengxin , Mu Rongjun , Cui Naigang
Published: September 2011

Purpose

The purpose of this paper is to address the flaws of traditional methods and fulfil the special fault‐tolerant re‐entry navigation requirements of reusable boost vehicle (RBV).

Design/methodology/approach

A kind of improved estimation method based on strong tracking unscented Kalman filter (STUKF) is put forward. According to the fact that the traditional state χ2‐test‐based fault diagnosis method is incompetent to detect the signal point small jerks and slowly varying fault in the measurement, a kind of original fault diagnosis technology based on STUKF is used to check the working states of navigation sensors.

Findings

The comparisons with χ2‐test method under typical failure distributions validate the perfect state tracking and fault diagnosis performances of this improved method.

Practical implications

This kind of state estimation and fault diagnosis method could be used in the navigation and guidance systems for many kinds of aeronautical and astronautical vehicles.

Originality/value

A kind of novel strong tracking state estimation filter is used, and a kind of very effective fault diagnosis criterion is put forward for the navigation of RBV.
Neural network based feedback error controller for helicopter
Authors: Vijaya Kumar M. , Sampath P. , Suresh S. , Omkar S.N. , Ganguli Ranjan
Published: September 2011

Purpose

This paper seeks to present a feedback error learning neuro‐controller for an unstable research helicopter.

Design/methodology/approach

Three neural‐aided flight controllers are designed to satisfy the ADS‐33 handling qualities specifications in pitch, roll and yaw axes. The proposed controller scheme is based on feedback error learning strategy in which the outer loop neural controller enhances the inner loop conventional controller by compensating for unknown non‐linearity and parameter uncertainties. The basic building block of the neuro‐controller is a nonlinear auto regressive exogenous (NARX) input neural network. For each neural controller, the parameter update rule is derived using Lyapunov‐like synthesis. An offline finite time training is used to provide asymptotic stability and on‐line learning strategy is employed to handle parameter uncertainty and nonlinearity.

Findings

The theoretical results are validated using simulation studies based on a nonlinear six degree‐of‐freedom helicopter undergoing an agile maneuver. The neural controller performs well in disturbance rejection is the presence of gust and sensor noise.

Practical implications

The neuro‐control approach presented in this paper is well suited to unmanned and small‐scale helicopters.

Originality/value

The study shows that the neuro‐controller meets the requirements of ADS‐33 handling qualities specifications of a helicopter.
On the probability of collision for crossing aircraft
Authors: Campos L.M.B.C. , Marques J.M.G.
Published: September 2011

Purpose

The purpose of this paper is to calculate the probability of collision of flying aircraft crossing on straight paths in any direction.

Design/methodology/approach

The probability of deviations from the intended flight paths is used to calculate the probability of collision that is integrated over time to cover whole events.

Findings

The probabilities of collision are calculated in terms of the r.m.s. position errors and encounter geometry, that is aircraft velocities and flight path angles and crossing angles.

Research limitations/implications

The method does not apply to aircraft flying in parallel tracks at the same velocity in air corridors: that case has been covered elsewhere, as well as the case of climbing or descending aircraft.

Practical implications

International Civil Aviation Organization (ICAO) specifies as target level of safety (TLS) a probability of collision not exceeding 5×10−9per hour. To meet the ICAO TLS standard, it is necessary to calculate collision probabilities for all stages of flight.

Social implications

A low collision probability is a safety metric; the value does depend on a realist choice of probability distribution.

Originality/value

Calculates the probability of collision for crossing flights, corresponding to a common scenario on air traffic management.
Hierarchical mission planning for multiple vehicles airdrop operation
Authors: Wei Tietao , Qu Xiangju , Wang Liuping
Published: September 2011

Purpose

Airdrop operation has become an important transportation mode due to its mobility and rapidity and mission planning is one of the critical steps in the preparation of an airdrop operation. The purpose of this paper is to propose an efficient mission planning method for airdrop operation using multiple vehicles.

Design/methodology/approach

A hierarchical mission planning method is proposed. According to the objectives of the action, the mission planning is divided into three planning levels to form the hierarchical structure and the constraints are distributed among them. By doing so, the proposed approach converts the original mission planning problem to a constrained optimization problem, which is solvable using existing mathematical methods.

Findings

On the basis of analysis, the mathematic models of three planning levels are established. Each level has its own optimization objective, taking part of constraints into account. The integrated mission scheme had been obtained step by step.

Practical implications

This paper systematically tackles the complicated multiple vehicles airdrop mission planning problem, and it provides a platform for optimizing the outcomes. The mathematical models established in this paper could apply in a variety of more complex mission scenarios.

Originality/value

This paper fulfils an urgent need to study how the advantages of airdrop operation can be maximized through planning airdrop mission schemes carefully.
Flight demonstrations of micro‐actuator controlled delta wing
Authors: Lee John , Newbern Scott , Tai Yu‐Chong , Ho Chih‐Ming , Adam Huang Po‐Hao
Published: September 2011

Purpose

The goal of this research is to demonstrate micro‐electro‐mechanical systems (MEMS)‐based transducers for aircraft maneuvering. Research in wind tunnels have shown that micro‐actuators can be used to manipulate leading edge vortices found on aerodynamic surfaces with moderate to highly swept leading edges, such as a delta wing. This has been labeled as the MEMS vortex shift control (MEMS‐VSC). The work presented in this paper seeks to detail the evolution of real‐world flight tests of this research using remotely piloted vehicles (RPVs).

Design/methodology/approach

Four different RPVs were constructed and used for flight tests to demonstrate the ability of using MEMS devices to provide flight control, primarily in the rolling axis.

Findings

MEMS devices for high angle‐of‐attack (AOA) turning flights have been demonstrated and the paper finds that the success of a complex project like the MEMS‐VSC requires the marriage of basic science expertise found in academia and the technical expertise found in industry.

Research limitations/implications

Owing to the need to test fly the RPVs at low altitudes for video documentation while performing high AOA maneuvers, the attrition of the RPVs becomes the dominant factor to the pace of research.

Practical implications

MEMS sensors and actuators can be used to augment flight control at high AOA, where conventional control surfaces typically experiences reduced effectiveness. Separately, the lessons learned from the integration efforts of this research provide a potentially near parallel case study to the development of ornithopter‐based micro aerial vehicles.

Originality/value

This is the only research‐to‐date involving the demonstration of the MEMS‐VSC on real‐world flight vehicles.