DP System Research Articles

Integrated Simulations of a Floating Crane Installation Vessel with DP systems in Waves

The nonlinear time-domain analysis method was implemented to carry out a series of integrated simulations for a deep-water crane vessel system composed of four sub components, including a floating vessel, lifted equipment, hoisting cable and dynamic positioning (hereinafter DP) system. The analysis of the coupled dynamics consists of the crane vessel and equipment connected using the crane wire, and the DP is modeled according to the wind, wave and current conditions. The DP systems were numerically implemented using a classical PD feedback controller, and various simulations of the deepwater installation were conducted using different conditions in order to evaluate the global performance of the floating crane vessel combined with the DP system.

Optimizing rooting and survival of oil palm (Elaeis guineensis) plantlets derived from somatic embryos

In species of the Arecaceae, initial conversion of somatic embryos to non-rooted plantlets (those with only shoot development and no roots) is common. A consistent methodology for improving rooting and survival of oil palm plantlets derived from somatic embryos was developed. Two experiments were carried out. In the first, non-rooted shoots regenerated via somatic embryogenesis were inoculated in nutrient medium supplemented with 0, 53.7, or 107.4 μM indole-3-butyric acid (IBA) or 1-naphthaleneacetic acid (NAA). In the second, the optimum treatment as determined in the first experiment was evaluated in three culture systems: semi-solid medium (SS), stationary liquid (SL), and double-phase system (DP), with and without the addition of activated charcoal. Next, the plantlets were acclimatized in a greenhouse, where the influence of the presence or absence of roots, the number of roots, the length of the main root, and the height of the shoot on survival were assessed. Supplementation with 53.7 μM IBA and the DP system without activated charcoal provided the highest percentage of rooted plantlets (92.9%) and number of roots (6.3) and improved the length of the aerial parts (11.0 cm) and the survival of the plantlets during the acclimatization (82.1%). The best survival of plantlets was obtained when they were acclimatized with at least one root and with a height greater than 7.5 cm.

Managing DP System Software - A Life-cycle Perspective

In a few decades, DP operations have gone from early prototyping to become a commodity and necessity to conduct most offshore operations. Today's DP vessels encompass offshore supply vessels, anchor-handlers, construction and diving vessels, shuttle tankers, semi-submersibles and drillships, as well as numerous other vessel types. Although the vessel types range widely in type and purpose, the DP systems are similar in structure and usually considered to be comprised of a number of different position reference and sensor systems, a DP computer system, a power system including generation, distribution and power management, and a propulsion system including thrusters, main propulsion and possibly rudders. At the heart of all these subsystems lies computer control systems, and at the heart of all computer control systems lies software.Experience from other industries shows that software is elusive and difficult to manage properly. None the less so for a DP vessel, where software from many different vendors come together to work as one integrated DP system. As technology has evolved and matured, the level of automation and integration has increased, and the complexity of the DP system has increased correspondingly. The software systems on a modern vessel by far exceeds any mechanical, electrical or hydraulic system in complexity and – more importantly – in lack of transparency. Do we have the right tools available to manage the risks associated with software on DP vessels today, both in the building phase and in the life-cycle of the vessel? And if so, are they understood and used correctly?This paper aims to highlight how independent Hardware-In-the-Loop (HIL) testing can be used to test, verify and validate the individual software components of the DP system, as well as the complete integrated system. The paper continues to show how HIL testing could be incorporated in the life-cycle of the vessel to manage and mitigate control system risk, both for newbuilds and sailing vessels.

EVALUATING CRITERIA FOR DP VESSELS

The paper presents the evaluating criteria for DP vessels. A few persons tried to give a simple tool for comparing the station keeping capability between different ships. It was started in the seventies when most vessels claiming to have a DP system would be carried away by the current only (the limit was 1.5 up to 2 knots). Mainly DNV and ABS, next IMO prepared the calculating methods for DP system evaluation during the design process to receive the DP class 1, 2 or 3. The regulations may help but it’s still only rough estimate. One of them is the most popular. It is the capability plot presenting at preliminary the polar diagram with number envelops, showing the vessel’s capability to keep position or heading with a certain combination of thrusters in operation. The number, type, total power (or thrust) and location of thrusters are vital for estimating the DP capability from the propulsion system. The other equipment is only accessories assisting the DP system. At the end the sea trial may check and confirm the DP class of the vessel. The real capability for station keeping will be verified during normal operation, essentially during emergency situations like electric network faults, propulsion system failure up to damages and fire. It is needed some indexes or parameters during the design process to avoid serious faults. The paper is a probe of becoming familiar with chosen criteria.

Linear fuzzy controller design for dynamic positioning system of surface ships

This paper presents a linear fuzzy controller design for dynamic positioning DP system of surface ships using optimal H

Abstract 3458: Role of the EphB1 gene in mediating migration, proliferation, and radiosensitization of medulloblastoma cells

Abstract Eph/ephrin signaling in a variety of cancers has been reported to promote aspects of tumorigenesis, including proliferation, migration, and angiogenesis. Medulloblastoma is an aggressive primitive neuroectodermal tumor originating in the cerebellum. Recently performed integrative genomic approach to a large cohort of medulloblastomas has identified four subtypes (A-D) based on clinical presentation, transcription profiles, genetic abnormalities, and clinical outcome. We show high levels of EphB1 expression in tumors derived from children with group D medulloblastomas, which are known to exhibit a poorer response to current therapies. The purpose of this study is to examine the effect knockdown of EphB1 has on cellular migration, proliferation, and radiosensitization of medulloblastoma tumors. Using a human-derived medulloblastoma cell line (DAOY) and small interfering RNA (siRNA) targeting EphB1, we compared cell migration in an electrical impedance-based transwell Boyden chamber assay (xCELLigence RTCA DP system). We show that siRNA knockdown of EphB1 results in significantly decreased migration. Assessment of proliferation by MTT assay indicates that knockdown of EphB1 affects cell cycle progression in DAOY. Results from cell cycle and sub-G1 analysis by flow cytometry demonstrate that knockdown of EphB1 results in G1 arrest. Our previous systems analysis investigation of global gene expression regulated by an intact ATM gene product also identified EphB1 as a downstream signaling molecule correlating with enhanced cellular radiation resistance. Our data strongly support EphB1 as an unequivocal target for radiation sensitization in human fibroblasts as well as in vitro medulloblastoma cell lines. siRNA knockdown of EphB1 expression in human medulloblastoma cell lines known to express high levels of EphB1 results in sensitization to ionizing radiation by clonogenic survival assays. Preliminary data from an in vivo xenograft medulloblastoma animal model suggest an enhanced response to radiation in tumors lacking the EphB1 gene. Our data indicate that EphB1 is a potential molecular target for medulloblastoma cancer treatment and radiosensitization. The mechanisms and downstream signaling cascades underlying EphB1's action on cell migration, proliferation, and cellular radiosensitization are currently under investigation. Citation Format: Nimrah A. Baig*, Olga Timofeeva*, Anatoly Dritschilo, Elena Pasquale, Marcel Kool, Brian Rood, Olga Rodriguez, Christopher Albanese^, Sana Karam^. Role of the EphB1 gene in mediating migration, proliferation, and radiosensitization of medulloblastoma cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3458. doi:10.1158/1538-7445.AM2014-3458

Modulating the phase structure of black D6 branes in canonical ensemble

There exists a dramatic difference in phase structure between charged black Dp-branes with $p < 5$ and charged black D5 or D6 branes. In [1], we found that the phase structure of charged black D5 system can be changed qualitatively to that of charged black Dp with $p < 5$ by adding the delocalized D1 branes but the similar change does not happen for the charged black D6 system through adding the delocalized D2 branes (Note that both D1/D5 and D2/D6 belong to the same type of D(p - 4)/Dp system). Adding the delocalized D4 branes to the black D6 branes doesn't work, either. In this paper, we consider adding the delocalized D0 branes, the only remaining lower dimensional branes, to the black D6 system for this purpose. We find that the delocalized charged black D0-branes alone share the same phase structure as the charged black D6 branes, having no van der Waals-Maxwell liquid-gas type. However, when the two are combined to form D0/D6, the resulting phase diagram finally gets changed dramatically to the wanted one, containing now the above liquid-gas type. This change arises from the interaction between D6 and the delocalized D0.

Characterization of Spontaneous and TGF-β-Induced Cell Motility of Primary Human Normal and Neoplastic Mammary Cells In Vitro Using Novel Real-Time Technology

The clinical complications derived from metastatic disease are responsible for the majority of all breast cancer related deaths. Since cell migration and invasion are a prerequisite for metastasis their assessment in patient cancer cells in vitro may have prognostic value for the tumor's metastatic capacity. We employed real-time cell analysis (RTCA) on the xCELLigence DP system to determine in vitro motility of patient-derived primary human breast cancer epithelial cells (HBCEC). Initially, the RTCA assay was validated using established human breast cancer cell lines with either an invasive (MDA-MB-231, MDA-MB-435s) or a non-invasive phenotype (MCF-7, MDA-MB-468), and primary NSCLC cells (Tu459). Previous standard assays of cell migration/invasion revealed that only MDA-MB-231, −435s, and Tu459 cells exhibited spontaneous and TGF-β1-stimulated migration and invasion through a Matrigel barrier. In the present study, the TGF-β1-stimulated activities could be blocked by SB431542, a potent kinase inhibitor of the TGF-β type I receptor ALK5. Application of the RTCA assay to patient-derived tumor cells showed that 4/4 primary HBCEC and primary NSCLC cells, but not normal human mammary epithelial cells (HMEC), displayed high spontaneous migratory and invasive activity which correlated with higher MMP-2 expression and uPA protein levels in HBCEC compared to HMEC. Upon treatment with TGF-β1, HBCEC exhibited morphologic and gene regulatory alterations indicative of epithelial-to-mesenchymal transition. However, exclusively the invasive but not the migratory activity of HBCEC was further enhanced by TGF-β1. This indicates the requirement for molecular, e.g. integrin interactions with Matrigel components in HBCEC in order to become responsive to pro-invasive TGF-β effects. Together, these results show for the first time that tumorigenic HBCEC but not normal HMEC possess a strong basal migratory as well as a basal and TGF-β1-inducible invasive potential. These findings qualify the RTCA assay as an in vitro migration/invasion testing system for patient-specific primary breast cancer cells.

Ciprofloxacin is a potential topoisomerase II inhibitor for the treatment of NSCLC.

Lung cancer is one of the most common tumors and its treatment is still inefficient. In our previous work we proved that ciprofloxacin has a different influence on five cancer cell lines. Here, we aimed to compare the biological effect of ciprofloxacin on cell lines representing different responses after treatment, thus A549 was chosen as a sensitive model, C6 and B16 as highly resistant. Three different cell lines were analyzed (A549, B16 and C6). The characterization of continuous cell growth was analyzed with the Real-Time Cell Analyzer (RTCA)-DP system. Cytoskeletal changes were demonstrated using immunofluorescence. The cell cycle was analyzed using flow cytometry. Ciprofloxacin was cytostatic only against the A549 cell line. In the case of other tested cell lines a cytostatic effect was not observed. Cytoskeletal analysis confirms the results obtained with RTCA-DP. A549 cells were inhibited in the G2/M phase suggesting a mechanism related to topoisomerase II inhibition. The biological effects of ciprofloxacin support the hypothesis that this drug can serve as an adjuvant treatment for lung cancer, due to its properties enabling topoisomerase II inhibition.

A Variant of Distributed P Systems for Real Time Cross Layer Optimization

Membrane computing models (also known as PS ystems) that solve opti- misation problems using genetic algorithms, ant colony optimisation, quantum-inspired evolutionary algorithm and particle swarm optimisation have been defined and are effi- ciently used in several applications. This paper describes the design of a variant of the existing Distributed P system (dP system) that is augmented with new features that enable centralised monitoring and communication with all the other components of the distributed system. This proposed model is titled Monitored Distributed P System (MDP System) and its innovative application in performing Cross Layer Optimisation in wireless adhoc networks is also presented. In the proposed MDP System each node in the network is represented by a Ps ystemthat can independently perform Cross Layer Optimisation using particle swarm optimisation. Discussions on the communica- tion complexity of the proposed model and the experimental results presented are also suggestive of the fact that the proposed Monitored Distributed P System is suitable for real time optimisation in a dynamic and distributed environment.

NY-ESO-1 expression in hepatocellular carcinoma: A potential new marker for early recurrence after surgery

NY-ESO-1 belongs to the cancer testis antigens (CTA) family, and is identified in a variety of tumors. Certain studies have demonstrated that NY-ESO-1 predicts tumor recurrence and treatment response. No reports are currently available regarding the correlation between NY-ESO-1 and the recurrence of hepatocellular carcinoma (HCC) following surgery. The purpose of the present study was to evaluate the association between NY-ESO-1 and relapse of HCC and to explore the possible mechanisms for this correlation. A total of 120 HCC patients were analyzed for the expression of NY-ESO-1 by immunohistochemistry (IHC). A stable NY-ESO-1 over-expressed HepG2 cell line (ESO-HepG2) was established to determine the biological effects of NY-ESO-1 on cell proliferation, cell cycle and migration by using the xCELLigence DP system, flow cytometry and xCELLigence SP system. NY-ESO-1 was positive in 28 of 120 (23.3%) HCC tumor tissues. NY-ESO-1 was not detectable in adjacent normal liver tissues. A close correlation was found between NY-ESO-1 expression and the recurrence of HCC following surgery (P=0.007). Kaplan-Meier analysis showed a shorter recurrence-free survival (RFS) for patients positive for NY-ESO-1 (log-rank test, P=0.003). The Cox regression model demonstrated that NY-ESO-1 expression was a significant independent predictor for the recurrence of HCC following curative surgery (P=0.022). Compared with HepG2 cells, ESO-HepG2 cells have increased migration but not proliferation ability. In conclusion, NY-ESO-1 expression is associated with worse HCC outcome following surgery, and the mechanism for this finding may be that NY-ESO-1 increases tumor cell migration.

Protein Kinase D Regulates Cofilin Activity through p21-activated Kinase 4

Dynamic reorganization of the actin cytoskeleton at the leading edge is required for directed cell migration. Cofilin, a small actin-binding protein with F-actin severing activities, is a key enzyme initiating such actin remodeling processes. Cofilin activity is tightly regulated by phosphorylation and dephosphorylation events that are mediated by LIM kinase (LIMK) and the phosphatase slingshot (SSH), respectively. Protein kinase D (PKD) is a serine/threonine kinase that inhibits actin-driven directed cell migration by phosphorylation and inactivation of SSH. Here, we show that PKD can also regulate LIMK through direct phosphorylation and activation of its upstream kinase p21-activated kinase 4 (PAK4). Therefore, active PKD increases the net amount of phosphorylated inactive cofilin in cells through both pathways. The regulation of cofilin activity at multiple levels may explain the inhibitory effects of PKD on barbed end formation as well as on directed cell migration.

Differential roles of Src in transforming growth factor-ß regulation of growth arrest, epithelial-to-mesenchymal transition and cell migration in pancreatic ductal adenocarcinoma cells

Both transforming growth factor (TGF)-ß and the non-receptor tyrosine kinase Src play major roles during tumorigenesis by regulating cell growth, epithelial-to-mesenchymal transition (EMT), migration/invasion and metastasis, but little is known about the signaling crosstalk between them. To interfere with Src function in vitro and in vivo many studies have employed the pharmacologic Src inhibitors PP2 and PP1. Both agents have recently been shown to be powerful inhibitors of TGF-ß receptor type I/ALK5 and type II. As this situation prohibited any definite conclusions with respect to the relative contribution of TGF-ß vs. Src signaling, we decided to reappraise a potential role of Src in TGF-ß1-mediated cellular responses using RNA and dominant-negative (dn) interference to block Src expression and function, respectively. In TGF-ß-responsive pancreatic ductal adenocarcinoma (PDAC) cells, we show that Src is activated by TGF-ß1 and that its specific inhibition strongly attenuated basal proliferation and enhanced TGF-ß1-mediated growth arrest. However, Src inhibition was unable to impair TGF-ß1-controlled EMT as evidenced by cell morphology and regulation of the epithelial marker E-cadherin. Despite its dispensibility for TGF-ß-induced EMT, specific inhibition of Src dramatically reduced basal and TGF-ß1-induced cell migration in Panc-1 cells as measured with a novel real-time migration assay (xCELLigence DP system). Biochemically, dnSrc inhibition failed to block TGF-ß1/ALK5-induced activation of Smad2 and Smad3, but partially inhibited transcriptional activation of TGF-ß/Smad-responsive reporter genes, and effectively blocked basal and TGF-ß1-induced activation of p38 MAPK. Together, the data provide evidence for a role of Src in the regulation of basal proliferation as well as in basal and TGF-ß1-mediated cell motility but not EMT in TGF-ß-responsive pancreatic (tumor) cells.

Solving Problems in a DistributedWay in Membrane Computing: dP Systems

Although P systems are distributed parallel computing devices, no explicit way of handling the input in a distributed way in this framework was considered so far. This note proposes a distributed architecture (based on cell-like P systems, with their skin membranes communicating through channels as in tissue-like P systems, according to specified rules of the antiport type), where parts of a problem can be introduced as inputs in various components and then processed in parallel. The respective devices are called dP systems, with the case of accepting strings called dP automata. The communication complexity can be evaluated in various ways: statically (counting the communication rules in a dP system which solves a given problem), or dynamically (counting the number of communication steps, of communication rules used in a computation, or the number of objects communicated). For each measure, two notions of “parallelizability" can be introduced. Besides (informal) definitions, some illustrations of these idea are provided for dP automata: each regular language is “weakly parallelizable" (i.e., it can be recognized in this framework, using a constant number of communication steps), and there are languages of various types with respect to Chomsky hierarchy which are “efficiently parallelizable" (they are parallelizable and, moreover, are accepted in a faster way by a dP automaton than by a single P automaton). Several suggestions for further research are made.

Genetic Differentiation of Winter Wheat Populations Following Exposure to Two Management Systems in Early Inbreeding Generations

Producers in the southern Great Plains usually dedicate fields of winter wheat (Triticum aestivum L.) to a grain‐only (GO) management system or one that incorporates grazing preceding grain harvest (dual‐purpose or DP system). We hypothesized that a grazing system may be applied as a selection tool during the early inbreeding generations to shift gene frequencies in favor of improved grazing tolerance and grain yielding ability. Grain yield and other key traits were compared among F5 bulk progenies of 24 populations exposed in the F2 to F4 generations to either system, including a Base set of F3 progenies and three cultivars. From GO and DP experiments conducted for 3 yr near Marshall, OK, the grain yield loss from GO to DP systems was 11% for ‘2174’ and ‘Custer’ and 24% for ‘Jagger’. Yields of DP selections exceeded the GO selections when tested in the DP system (220 kg ha−1 differential, P &lt; 0.01) and in the GO system (80 kg ha−1, P = 0.01), with neutral effects on grain volume weight and protein concentration. Vegetative growth habit of DP and GO selections were visibly differentiated. When targeting a DP management system, derivation of bulk populations for line selection should utilize the DP system as a selection environment during the early inbreeding generations. This approach should not carry a universal yield penalty for GO environments when the breeding target includes both DP and GO systems.

다물체 연성효과를 고려한 부유체의 동적거동 안전성 해석

Recently, there are several problems in space, contiguity and facility of the existing harbors issued due to the trend of enlarging the container capacity of the large container vessel, the Mobile Harbor has been proposed conceptually as an effective solution for those problems. This concept is a kind of transfer loader of the containers from the large container ship, which is a floating barge with a catamaran type in the underwater part, and so prompt maneuverability and work effectiveness. For the safe mooring of two floating bodies, a container and the mobile harbor, in the near sea apart from the quay, a robot arm mooring facility specially devised would be designed and verified through comparison study under various environmental sea condition in the inner and outer harbor. DP system (Dynamic Positioning System) using the azimuth thruster and a pneumatic fender, etc, will be considered as a next research topic for the mooring security of multi-body floaters.

Confinement and nonperturbative tachyons in brane-antibrane systems

We present a worldvolume effective action suitable for the study of the confined phase of a (Dp,Dp) system at weak coupling. We identify the mechanism by which the fundamental string arises from this action as a confined electric flux string when the Dp and the Dp annihilate. We construct an explicit dual action, more suitable for the study of the strong coupling regime, and show that it realizes a generalized Higgs-Stueckelberg phase for the (relative) (p-2)-form field dual to the (overall) Born-Infeld vector. This is the mechanism put forward by Yi and collaborators based on duality arguments in order to explain the breaking of the overall U(1) gauge group at strong coupling. Indeed, in our dual description the Goldstone boson is a (p-3) form magnetically charged with respect to the overall Born-Infeld vector field. This indicates that the condensing tachyonic objects originate from open D(p-2)-branes stretched between the brane and the antibrane. Our results provide an explicit realization of the breaking of the overall U(1) gauge group perturbatively, in a way consistent with the duality symmetries of string theory.

DIELECTRON MEASUREMENTS IN NN INTERACTIONS AT A BEAM ENERGY OF 1.25 GeV WITH HADES

The dielectron yield in pp and dp reactions at a beam kinetic energy of 1.25 GeV/u has been measured using the HADES spectrometer at GSI. In proton-proton reactions the most abundant source above the π0 Dalitz region is expected to be Δ Dalitz decay. The obsearved large difference in dielectron production in pp and dp systems suggests that dielectron production in the dp system is dominated by a np process. In order to separate Δ Dalitz decays and np bremsstrahlung we compare the dielectron yield observed in pp with the one of dp reactions measured at the same beam energy.

Digital predistortion linearizes wireless power amplifiers

When compared to other linearization methods, adaptive DP provides sufficient linearization with less complex RF hardware by depending primarily upon DSP rather than analog manipulation. The adaptive DP system may be implemented in EDA software along with interconnected test equipment (arbitrary RF signal source and vector signal analyzer). Through the use of a training signal, a simple adaptive algorithm may be employed to update the LUT coefficients until an optimum setting is achieved and used to predistort the input to the amplifier. This connected solution approach can provide key information to design engineers for optimizing the DSP architecture of a PA. For future work, other issues are taken into account, such as temperature and electrical memory effects.

FPSO-Shuttle Tanker Collision Risk Reduction

To reduce the occurrence of tanker drive-off, and to reduce the probability of recovery failure should drive-off happen, are two basic principles to reduce FPSO and DP shuttle tanker collision in tandem offloading. In this paper we focus on measures to reduce recovery failure. Previous analyses revealed that recovery failure probability is high due to a lack of time for the DP operator to initiate the recovery action in a tanker drive-off scenario. To increase the time window and to reduce the operator reaction time are therefore two main principles of recovery failure reduction. A substantial increase of the separation distance between FPSO and the tanker, and a possible reduction of the main propeller(s) forward thrust that can be used by the tanker DP system are two measures to increase the time window. The effective reduction of operator reaction time can be achieved by a number of measures, i.e., selection, training, procedure, crew resource management, and automation support, which are designed to improve early detection as well as effectively reduce the DP operator’s time in diagnosis and situation awareness.