bluuebunny/crossref_metadata_2025 huggingface dataset:
Confirmation of a Nonlinear Model Predictive Control Strategy Applied to a Permanent Magnet Linear Generator for Wave-Energy Conversion
Authors: Tom Nathan
Published: September 2014

This paper begins with a brief review of the time-domain equation of motion for a generic floating body. The equation of motion of the floating body was modified to account for the influence of a power-take-off unit (PTO) to predict the hydrodynamic and electromechanical performance of the coupled system. As the damping coefficient is considered the dominant contribution to the PTO reaction force, the optimum non time-varying damping values were first presented for all frequencies, recovering the well-known impedance-matching principle at the coupled resonance frequency. In an effort to further maximize power absorption in both regular and irregular wave environments, nonlinear model predictive control (NMPC) was applied to the model-scale point absorber developed at UC Berkeley. The proposed NMPC strategy requires a PTO unit that could be turned on and off instantaneously, leading, interestingly to electrical sequences where the generator would be inactive for up to 60% of the wave period. In order to validate the effectiveness of this NMPC strategy, an in-house designed permanent magnet linear generator (PMLG) was chosen as the PTO. The time-varying performance of the PMLG was first characterized by dry-bench tests, using mechanical relays to control the electromagnetic conversion process. Following this, the physical set-up was transferred to the wave tank. The on/off sequencing of the PMLG was tested under regular and irregular wave excitation to validate NMPC simulations using control inputs obtained from running the control algorithm offline. Experimental results indicate that successful implementation was achieved and the absorbed power using NMPC was up to 50% greater than the passive system, which utilized no controller. However, after considering the PMLG mechanical-to-electrical conversion efficiency the useful electrical power output was not consistently maximized. To improve output power, a mathematical relation between the efficiency and damping magnitude of the PMLG was inserted in the system model to maximize the electrical power output through continued use of NMPC. Of significance, results from these latter simulations provided a damping time series that was active over a larger portion of the wave period and required the actuation of the applied electrical load connected to the PMLG, rather than a simple on/off type control.
Analysis and Probabilistic Modeling of the Stationary Ice Loads Stochastic Process With Lognormal Distribution
Authors: Zvyagin Petr , Sazonov Kirill
Published: September 2014

Until recent times researchers who investigated ice loads stochastic processes usually stated the fact of normal distribution for them. In the paper the model of a stationary stochastic process with a lognormal distribution for ice loads is offered. This model relates to the strain gauge transducer ice loads measurements as well as to some examples considered in different papers that were published earlier.

For this model dependencies of the autocorrelation function were found that allows to simulate the ice loads process relatively easily. The procedure of such a simulation is described in details and the example of the analysis and simulation ice loads measurements is provided.
Finite Element Analysis Applied in Structural Integrity Management
Authors: Dybwad Jacob , Bryndum Mads , Hollingworth Russell
Published: September 2014

During the periodic inspection of the Alvheim subsea system 2013 a number of cracks were observed at the Mid Water Arch (MWA) tether anchoring arrangement. The MWA and associated anchor block are critical design elements. Detailed investigations were initiated in order to determine future development of the cracks and their severity.

The application of advanced non-linear finite element analysis as part of the inspection and maintenance strategy resulted in significant cost savings compared to a solution based on immediate mitigation action.

This paper describes the background for occurrence of these cracks and the analyses used to determine their development:

• The cracks are located in non-loadbearing locking brackets. The function of the brackets is primarily to secure the pins connecting the top part of the tether hinge to the anchor block.

• During construction the locking brackets were welded to the pin and to the tether hinge. This way the non-structural element became part of the load bearing system resulting in very high stresses in the bracket and subsequent crack development. It could not immediately be excluded that the cracks observed could initiate further cracking into main bearing parts of the hinge.

• FE modeling using Abaqus [1] was used to analyze the criticality of the situation. Non-linear material properties and removal of elements were applied in order to simulate crack initiation and crack growth.

The system was analyzed by modelling the load paths from initial assembly on land, installation loads and finally the loads during operation. Removal of elements was introduced to replicate the crack growth pattern observed on ROV still photos from periodic surveys 2012 and 2013.

The analysis documented the principle mechanism behind the crack development and further demonstrated that the risk of failure of any of the load bearing elements was negligible.

The results of the analysis provided the necessary documentation for the appropriate precautions and at the same time plan for execution of mitigation measures which would have minimal economic impact.
TGF-β–induced epithelial-to-mesenchymal transition proceeds through stepwise activation of multiple feedback loops
Authors: Zhang Jingyu , Tian Xiao-Jun , Zhang Hang , Teng Yue , Li Ruoyan , Bai Fan , Elankumaran Subbiah , Xing Jianhua
Published: September 2014

Experimental and computational analyses identify multiple cell populations during the epithelial-to-mesenchymal transition.
Science Signaling
Podcast: 30 September 2014
Authors: Altman Amnon , VanHook Annalisa M.
Published: September 2014

The guanine nucleotide exchange factor SLAT promotes T cell activation by binding to IP
3
receptor 1 at the endoplasmic reticulum.
A Complex Network Makes Simple Pores
Authors: Hines Pamela J.
Published: September 2014

The molecular pathways that regulate an essential adult stem cell lineage in plant stomata are dissected.
Mitochondria Are Getting Fat
Authors: Berndt Jason D.
Published: September 2014

A fragment of the cytoplasmic tail of the cadherin Fat localizes to the mitochondria and participates in oxidative phosphorylation.
Complex Polymorphisms in the Plasmodium falciparum Multidrug Resistance Protein 2 Gene and Its Contribution to Antimalarial Response
Authors: Veiga Maria Isabel , Osório Nuno S. , Ferreira Pedro Eduardo , Franzén Oscar , Dahlstrom Sabina , Lum J. Koji , Nosten Francois , Gil José Pedro
Published: September 2014

Plasmodium falciparum
has the capacity to escape the actions of essentially all antimalarial drugs. ATP-binding cassette (ABC) transporter proteins are known to cause multidrug resistance in a large range of organisms, including the
Apicomplexa
parasites.
P. falciparum
genome analysis has revealed two genes coding for the multidrug resistance protein (MRP) type of ABC transporters:
Pfmrp1
, previously associated with decreased parasite drug susceptibility, and the poorly studied
Pfmrp2
. The role of
Pfmrp2
polymorphisms in modulating sensitivity to antimalarial drugs has not been established. We herein report a comprehensive account of the
Pfmrp2
genetic variability in 46 isolates from Thailand. A notably high frequency of 2.8 single nucleotide polymorphisms (SNPs)/kb was identified for this gene, including some novel SNPs. Additionally, we found that
Pfmrp2
harbors a significant number of microindels, some previously not reported. We also investigated the potential association of the identified
Pfmrp2
polymorphisms with altered
in vitro
susceptibility to several antimalarials used in artemisinin-based combination therapy and with parasite clearance time. Association analysis suggested
Pfmrp2
polymorphisms modulate the parasite's
in vitro
response to quinoline antimalarials, including chloroquine, piperaquine, and mefloquine, and association with
in vivo
parasite clearance. In conclusion, our study reveals that the
Pfmrp2
gene is the most diverse ABC transporter known in
P. falciparum
with a potential role in antimalarial drug resistance.
Beneficial Effect of Oral Tigecycline Treatment on Clostridium difficile Infection in Gnotobiotic Piglets
Authors: Kim Hyeun Bum , Zhang Quanshun , Sun Xingmin , Beamer Gillian , Wang Yuankai , Tzipori Saul
Published: September 2014

The efficacy of oral tigecycline treatment (2 mg/kg of body weight for 7 days) of
Clostridium difficile
infection (CDI) was evaluated in the gnotobiotic pig model, and its effect on human gut microflora transplanted into the gnotobiotic pig was determined. Tigecycline oral treatment improved survival, clinical signs, and lesion severity and markedly decreased concentrations of
Firmicutes
but did not promote CDI. Our data showed that oral tigecycline treatment has a potential beneficial effect on the treatment of CDI.
Effect of Fluorescent Dyes on
In Vitro
-Differentiated, Late-Stage Plasmodium falciparum Gametocytes
Authors: Gebru Tamirat , Mordmüller Benjamin , Held Jana
Published: September 2014

Plasmodium falciparum
gametocytes are not associated with clinical symptoms, but they are responsible for transmitting the pathogen to mosquitoes. Therefore, gametocytocidal interventions are important for malaria control and resistance containment. Currently available drugs and vaccines are not well suited for that purpose. Several dyes have potent antimicrobial activity, but their use against gametocytes has not been investigated systematically. The gametocytocidal activity of nine synthetic dyes and four control compounds was tested against stage V gametocytes of the laboratory strain 3D7 and three clinical isolates of
P. falciparum
with a bioluminescence assay. Five of the fluorescent dyes had submicromolar 50% inhibitory concentration (IC
50
) values against mature gametocytes. Three mitochondrial dyes, MitoRed, dihexyloxacarbocyanine iodide (DiOC6), and rhodamine B, were highly active (IC
50
s < 200 nM). MitoRed showed the highest activity against gametocytes, with IC
50
s of 70 nM against 3D7 and 120 to 210 nM against clinical isolates. All compounds were more active against the laboratory strain 3D7 than against clinical isolates. In particular, the endoperoxides artesunate and dihydroartemisinin showed a 10-fold higher activity against 3D7 than against clinical isolates. In contrast to all clinically used antimalarials, several fluorescent dyes had surprisingly high
in vitro
activity against late-stage gametocytes. Since they also act against asexual blood stages, they shall be considered starting points for the development of new antimalarial lead compounds.
Genome Sequencing of an Extended Series of NDM-Producing Klebsiella pneumoniae Isolates from Neonatal Infections in a Nepali Hospital Characterizes the Extent of Community- versus Hospital-Associated Transmission in an Endemic Setting
Authors: Stoesser N. , Giess A. , Batty E. M. , Sheppard A. E. , Walker A. S. , Wilson D. J. , Didelot X. , Bashir A. , Sebra R. , Kasarskis A. , Sthapit B. , Shakya M. , Kelly D. , Pollard A. J. , Peto T. E. A. , Crook D. W. , Donnelly P. , Thorson S. , Amatya P. , Joshi S.
Published: September 2014

NDM-producing
Klebsiella pneumoniae
strains represent major clinical and infection control challenges, particularly in resource-limited settings with high rates of antimicrobial resistance. Determining whether transmission occurs at a gene, plasmid, or bacterial strain level and within hospital and/or the community has implications for monitoring and controlling spread. Whole-genome sequencing (WGS) is the highest-resolution typing method available for transmission epidemiology. We sequenced carbapenem-resistant
K. pneumoniae
isolates from 26 individuals involved in several infection case clusters in a Nepali neonatal unit and 68 other clinical Gram-negative isolates from a similar time frame, using Illumina and PacBio technologies. Within-outbreak chromosomal and closed-plasmid structures were generated and used as data set-specific references. Three temporally separated case clusters were caused by a single NDM
K. pneumoniae
strain with a conserved set of four plasmids, one being a 304,526-bp plasmid carrying
bla
NDM-1
. The plasmids contained a large number of antimicrobial/heavy metal resistance and plasmid maintenance genes, which may have explained their persistence. No obvious environmental/human reservoir was found. There was no evidence of transmission of outbreak plasmids to other Gram-negative clinical isolates, although
bla
NDM
variants were present in other isolates in different genetic contexts. WGS can effectively define complex antimicrobial resistance epidemiology. Wider sampling frames are required to contextualize outbreaks. Infection control may be effective in terminating outbreaks caused by particular strains, even in areas with widespread resistance, although this study could not demonstrate evidence supporting specific interventions. Larger, detailed studies are needed to characterize resistance genes, vectors, and host strains involved in disease, to enable effective intervention.
Fibronectin-Degrading Activity of Trypanosoma cruzi Cysteine Proteinase Plays a Role in Host Cell Invasion
Authors: Maeda Fernando Yukio , Cortez Cristian , Izidoro Mario Augusto , Juliano Luiz , Yoshida Nobuko
Published: September 2014

Trypanosoma cruzi, the agent of Chagas disease, binds to diverse extracellular matrix proteins. Such an ability prevails in the parasite forms that circulate in the bloodstream and contributes to host cell invasion. Whether this also applies to the insect-stage metacyclic trypomastigotes, the developmental forms that initiate infection in the mammalian host, is not clear. UsingT. cruziCL strain metacyclic forms, we investigated whether fibronectin bound to the parasites and affected target cell invasion. Fibronectin present in cell culture medium bound to metacyclic forms and was digested by cruzipain, the majorT. cruzicysteine proteinase. G strain, with negligible cruzipain activity, displayed a minimal fibronectin-degrading effect. Binding to fibronectin was mediated by gp82, the metacyclic stage-specific surface molecule implicated in parasite internalization. When exogenous fibronectin was present at concentrations higher than cruzipain can properly digest, or fibronectin expression was stimulated by treatment of epithelial HeLa cells with transforming growth factor beta, the parasite invasion was reduced. Treatment of HeLa cells with purified recombinant cruzipain increased parasite internalization, whereas the treatment of parasites with cysteine proteinase inhibitor had the opposite effect. Metacyclic trypomastigote entry into HeLa cells was not affected by anti-β1 integrin antibody but was inhibited by anti-fibronectin antibody. Overall, our results have indicated that the cysteine proteinase ofT. cruzimetacyclic forms, through its fibronectin-degrading activity, is implicated in host cell invasion.
Bordetella parapertussis Survives inside Human Macrophages in Lipid Raft-Enriched Phagosomes
Authors: Gorgojo Juan , Harvill Eric T. , Rodríguez Maria Eugenia
Published: September 2014

Bordetella parapertussis
is a human pathogen that causes whooping cough. The increasing incidence of
B. parapertussis
has been attributed to the lack of cross protection induced by pertussis vaccines. It was previously shown that
B. parapertussis
is able to avoid bacterial killing by polymorphonuclear leukocytes (PMN) if specific opsonic antibodies are not present at the site of interaction. Here, we evaluated the outcome of
B. parapertussis
innate interaction with human macrophages, a less aggressive type of cell and a known reservoir of many persistent pathogens. The results showed that in the absence of opsonins, O antigen allows
B. parapertussis
to inhibit phagolysosomal fusion and to remain alive inside macrophages. The O antigen targets
B. parapertussis
to lipid rafts that are retained in the membrane of phagosomes that do not undergo lysosomal maturation. Forty-eight hours after infection, wild-type
B. parapertussis
bacteria but not the O antigen-deficient mutants were found colocalizing with lipid rafts and alive in nonacidic compartments. Taken together, our data suggest that in the absence of opsonic antibodies,
B. parapertussis
survives inside macrophages by preventing phagolysosomal maturation in a lipid raft- and O antigen-dependent manner. Two days after infection, about 15% of macrophages were found loaded with live bacteria inside flotillin-enriched phagosomes that had access to nutrients provided by the host cell recycling pathway, suggesting the development of an intracellular infection. IgG opsonization drastically changed this interaction, inducing efficient bacterial killing. These results highlight the need for
B. parapertussis
opsonic antibodies to induce bacterial clearance and prevent the eventual establishment of cellular reservoirs of this pathogen.
The Type II Secretion System Delivers Matrix Proteins for Biofilm Formation by Vibrio cholerae
Authors: Johnson Tanya L. , Fong Jiunn C. , Rule Chelsea , Rogers Andrew , Yildiz Fitnat H. , Sandkvist Maria
Published: September 2014

Gram-negative bacteria have evolved several highly dedicated pathways for extracellular protein secretion, including the type II secretion (T2S) system. Since substrates secreted via the T2S system include both virulence factors and degradative enzymes, this secretion system is considered a major survival mechanism for pathogenic and environmental species. Previous analyses revealed that the T2S system mediates the export of ≥20 proteins in
Vibrio cholerae
, a human pathogen that is indigenous to the marine environment. Here we demonstrate a new role in biofilm formation for the
V. cholerae
T2S system, since wild-type
V. cholerae
was found to secrete the biofilm matrix proteins RbmC, RbmA, and Bap1 into the culture supernatant, while an isogenic T2S mutant could not. In agreement with this finding, the level of biofilm formation in a static microtiter assay was diminished in T2S mutants. Moreover, inactivation of the T2S system in a rugose
V. cholerae
strain prevented the development of colony corrugation and pellicle formation at the air-liquid interface. In contrast, extracellular secretion of the exopolysaccharide VPS, an essential component of the biofilm matrix, remained unaffected in the T2S mutants. Our results indicate that the T2S system provides a mechanism for the delivery of extracellular matrix proteins known to be important for biofilm formation by
V. cholerae
. Because the T2S system contributes to the pathogenicity of
V. cholerae
by secreting proteins such as cholera toxin and biofilm matrix proteins, elucidation of the molecular mechanism of T2S has the potential to lead to the development of novel preventions and therapies.
A rare native mitral valve endocarditis successfully treated after surgical correction
Authors: Garcia Daniel C , Nascimento Rhanderson , Soto Victor , Mendoza Cesar E
Published: September 2014

Mycobacterium abscessusandKocuriaspecies are rare causes of infections in humans. Endocarditis by these agents has been reported in only 11 cases.M. abscessusis a particularly resistant organism and treatment requires the association of antibiotics for a prolonged period of time. We report a case of native mitral valve bacterial endocarditis due toM. abscessusandKocuriaspecies in a 48-year-old man with a history of intravenous drug use. The case was complicated by a perforation of the posterior mitral valve leaflet, leading to surgical mitral valve replacement. Cultures from the blood and mitral valve disclosedM. abscessusandKocuriaspecies. The patient was treated for 6 months with clarithromycin, imipenem and amikacin, with resolution of symptoms. Repeated blood cultures were negative. Acid-fast staining should be done in subacute endocarditis in order to identify rapidly growing mycobacteria.
Perforated duodenal diverticulae: importance for the surgeon and gastroenterologist
Authors: Haboubi Danya , Thapar Ankur , Bhan Chetan , Oshowo Ayo
Published: September 2014

We present the case of a 78-year-old woman who was admitted for an elective left hemicolectomy for diverticular disease. Two days following the elective procedure, bilious fluid was noted in her pelvic drain. The patient returned to theatre, where a perforated duodenal diverticulum was excised and the defect primarily repaired. The patient then developed a low output enterocutaneous fistula which was treated conservatively with nasojejunal feeding and resolved spontaneously.
Uneven inputs of woody debris to Appalachian streams from superstorm Sandy
Authors: Andrew Ross G. , Hartman Kyle J.
Published: September 2014

Headwater streams are the beginnings of fluvial networks and therefore fill a critical role in the development of the Earth’s drainages. Therefore, it is important that we understand the role that disturbances have on these systems and how they translate disturbance downstream. Hurricane Sandy struck the eastern seaboard of the United States in late October 2012 and produced record snowfall in the Appalachian Mountains, which caused widespread destruction of trees and subsequent deposition of large wood (LW; pieces ≥1.0 m × 0.05 m) in many headwater streams throughout the region. We investigated these effects in 25 West Virginia headwater streams and found varying levels (0%–195% change from previous annual data; 0–820 LW pieces·km−1) of new wood additions. When compared with years prior to Sandy, the rate of LW deposition was significant across all size classes and streams (p < 0.0001). We also found a significantly (p < 0.01) negative pattern of LW impact based upon elevation, with higher elevations receiving lower levels of LW deposition. This research provides a unique glimpse at the initial magnitude of natural wood addition on headwater streams following a large disturbance.
Twisty itsy bitsy topological field theory
Authors: Mathews Daniel V.
Published: September 2014

We extend the topological field theory (itsy bitsy topological field theory) of our previous work from mod 2 to twisted coefficients. This topological field theory is derived from sutured Floer homology (SFH) but described purely in terms of surfaces with signed points on their boundary (occupied surfaces) and curves on those surfaces respecting signs (sutures). It has information-theoretic (itsy) and quantum-field-theoretic (bitsy) aspects. In the process we extend some results of SFH, consider associated ribbon graph structures, and construct explicit admissible Heegaard decompositions.
Experiments on Optimizing the Performance of Stencil Codes with SPL Conqueror
Authors: Grebhahn Alexander , Kuckuk Sebastian , Schmitt Christian , Köstler Harald , Siegmund Norbert , Apel Sven , Hannig Frank , Teich Jürgen
Published: September 2014

A standard technique for numerically solving elliptic partial differential equations on structured grids is to discretize them, and, then, to apply an efficient geometric multi-grid solver. Unfortunately, finding the optimal choice of multi-grid components and parameter settings is challenging and existing auto-tuning techniques fail to explain performance-optimal settings. To improve the state of the art, we explore whether recent work on optimizing configurations of product lines can be applied to the stencil-code domain. In particular, we extend the domain-independent tool SPL Conqueror in an empirical study to predict the performance-optimal configurations of three geometric multi-grid stencil codes: a program using HIPAcc, the evaluation prototype HSMGP, and a program using DUNE. For HIPAcc, we reach an prediction accuracy of 96%, on average, measuring only 21.4% of all configurations; we predict a configuration that is nearly optimal after measuring less than 0.3% of all configurations. For HSMGP, we predict performance with an accuracy of 97% including the performance-optimal configuration, while measuring 3.2% of all configurations. For DUNE, we predict performance of all configurations with an accuracy of 86% after measuring 3.3% of all configurations. The performance-optimal configuration is within the 0.5% configurations predicted to perform best.
High-Level Programming of Stencil Computations on Multi-GPU Systems Using the SkelCL Library
Authors: Steuwer Michel , Haidl Michael , Breuer Stefan , Gorlatch Sergei
Published: September 2014

The implementation of stencil computations on modern, massively parallel systems with GPUs and other accelerators currently relies on manually-tuned coding using low-level approaches like OpenCL and CUDA. This makes development of stencil applications a complex, time-consuming, and error-prone task. We describe how stencil computations can be programmed in our SkelCL approach that combines high-level programming abstractions with competitive performance on multi-GPU systems. SkelCL extends the OpenCL standard by three high-level features: 1) pre-implemented parallel patterns (a.k.a. skeletons); 2) container data types for vectors and matrices; 3) automatic data (re)distribution mechanism. We introduce two new SkelCL skeletons which specifically target stencil computations – MapOverlap and Stencil – and we describe their use for particular application examples, discuss their efficient parallel implementation, and report experimental results on systems with multiple GPUs. Our evaluation of three real-world applications shows that stencil code written with SkelCL is considerably shorter and offers competitive performance to hand-tuned OpenCL code.
A 80-MHz-to-410-MHz 16-Phases DLL Based on Improved Dead-Zone Open-Loop Phase Detector and Reduced-Gain Charge Pump
Authors: Kazeminia Sarang , Mowloodi Sobhan Sofi , Hadidi Khayrollah
Published: September 2014

In this paper, a low jitter 16-phases delay locked loop (DLL) is proposed based on a simple and sensitive phase detector (PD). Dead-zone of the proposed PD is improved in compare to the conventional structures where the pulse generator postpones PD response and reduces the sensitivity. Also, the conventional structure of charge pumps is modified to inject small charge throughout the continuous outputs of PD. Smaller bias current is provided in charge pump via subtracting tail currents of intentionally mismatched differential pairs. Duty cycle of output differential phases is adjusted to around 50% using common mode setting strategy on delay elements. Simulation results confirm that DLL loop can provide 16-phases in frequency range of 80 to 410 MHz, consuming total power of 3.5 and 5.6 mW, respectively. The dead-zone of PD is also reduced from 80 to 14 ps when the pulse generator section is eliminated. Also, RMS jitter of about 45 and 1.76 ps are obtained at 80 and 410 MHz, respectively, when the supply voltage is subject to around 40 mV peak-to-peak noise disturbances. The proposed DLL can be implemented in less than 0.05 mm2 active area in a 0.18 μm CMOS technology.
Sensitivity Study of Pseudodynamic Algorithm with Structure-Dependent Quadrature Equations
Authors: Chang Shuenn-Yih
Published: September 2014

An estimated initial stiffness matrix is generally needed to determine the coefficient matrices of quadrature equations for a structure-dependent pseudodynamic algorithm. It is shown herein that an experimentally determined initial stiffness matrix is, in general, close to the true initial stiffness matrix if an imposed displacement is small enough. This case is often encountered in practice. The case where an estimated initial stiffness is different from a true initial stiffness for employing a structure-dependent pseudodynamic algorithm is also explored. The numerical properties and error propagation properties are evaluated as a function of the initial stiffness ratio, which is the ratio of an estimated initial stiffness over a true initial stiffness. In general, accuracy and error propagation properties are insensitive to the initial stiffness ratio. It seems that the change of bifurcation point between unconditional stability and conditional stability is of worth noting. In order to avoid this stability problem, guidelines are recommended if a structure-dependent pseudodynamic algorithm is used.
THE MEDIATING EFFECT OF WORK ENGAGEMENT ON THE RELATIONSHIP BETWEEN SELF-LEADERSHIP AND INDIVIDUAL INNOVATION
Authors: GOMES CATARINA , CURRAL LUIS , CAETANO ANTÓNIO
Published: September 2014

It has already been demonstrated that individual innovation within the workplace is the fundamental underpinning of high-performance organisations. The aim of this study is to explore the relationship between self-leadership, work engagement and individual innovation. Because innovation manifests itself when individuals feel engaged with their work, we propose that this positive affective motivational state will mediate the relationship between self-leadership skills and individual innovation. To study these relationships, data were collected from a sample of 337 nurses and doctors who work at an integrated health care unit. Our results show a positive relationship between self-leadership, work engagement and individual innovation. Furthermore, the results showed that work engagement had a mediating effect on the relationship between self-leadership and individual innovation. Overall, this research will contribute towards gaining more insights into the role that self-leadership and work engagement play in individual innovation. In addition, it will provide insights into new interventions that promote the development of innovation at work.
An Approach to Developing Local Climate Change Environmental Public Health Indicators, Vulnerability Assessments, and Projections of Future Impacts
Authors: Houghton Adele , English Paul
Published: September 2014

Environmental public health indicators (EPHIs) are used by local, state, and federal health agencies to track the status of environmental hazards; exposure to those hazards; health effects of exposure; and public health interventions designed to reduce or prevent the hazard, exposure, or resulting health effect. Climate and health EPHIs have been developed at the state, federal, and international levels. However, they are also needed at the local level to track variations in community vulnerability and to evaluate the effectiveness of interventions designed to enhance community resilience. This review draws on a guidance document developed by the U.S. Council of State and Territorial Epidemiologists’ State Environmental Health Indicators Collaborative climate change working group to present a three-tiered approach to develop local climate change EPHIs. Local climate change EPHIs can assist local health departments (LHDs) in implementing key steps of the 10 essential public health services and the U.S. Centers for Disease Control and Prevention’s Building Resilience Against Climate Effects framework. They also allow LHDs to incorporate climate-related trends into the larger health department planning process and can be used to perform vulnerability assessments which can be leveraged to ensure that interventions designed to address climate change do not exacerbate existing health disparities.
Competition with Online and Offline Demands considering Logistics Costs Based on the Hotelling Model
Authors: Hu Zhi-Hua , Wei Chen , Li Qing , Xiao Fan
Published: September 2014

Through popular information technologies (e.g., call centers, web portal, ecommerce and social media, etc.), traditional shops change their functions for servicing online demands while still providing offline sales and services, which expand the market and the service capacity. In the Hotelling model that formulates the demand effect by considering just offline demand, the shops in a line city will locate at the center as a the result of competition by games. The online demands are met by the delivery logistics services provided by the shops with additional cost; the consumers’ waiting time after their orders also affects their choices for shops. The main purpose is to study the effects of the following aspects on the shops’ location competition: two logistics costs (consumers’ travelling cost for offline demands and the shops’ delivery logistics cost for online demands), the consumers’ waiting cost for online orders, and the ratios of online demands to the whole demands. Therefore, this study primarily contributes to the literature on the formulation of these aspects by extending the Hotelling model. These features and effects are demonstrated by experiments using the extended Hotelling models.
Study of Associated Genetic Variants in Indian Subjects Reveals the Basis of Ethnicity Related Differences in Susceptibility to Venous Thromboembolism
Authors: Kumari Babita , Srivastava Swati , Chatterjee Tathagat , Vardhan Rig , Tyagi Tarun , Gupta Neha , Sahu Anita , Chandra Khem , Ashraf Mohammad Zahid
Published: September 2014

The genetic variants linked with the susceptibility of individuals to VTE are well known; however, the studies explaining the ethnicity based difference in susceptibility to VTE are limited. Present study assesses mutations in six candidate genes contributing to the etiology of VTE in Indian subjects. The study comprised 93 VTE patients and 102 healthy controls. A PCR-RFLP based analysis was performed for nine mutations in the following genes associated with VTE: favtor V Leiden (FVL), prothrombin, tissue factor pathway inhibitor (TFPI), fibrinogen-beta, plasminogen activator inhibitor 1 (PAI-1), and methylene tetrahydrofolatereductase (MTHFR). All the subjects were found to be monomorphic for FVL 1691G/A, prothrombin 20210G/A and TFPI −536C/T mutations. The mutation in the MTHFR gene (677C/T) was observed only in patients. Contrarily, higher frequency of mutation in the PAI-1 −844G/A and the fibrinogen-β−455G/A was observed in controls in comparison to the patients. This study suggests that the PAI-1 −844G/A and fibrinogen-β−455G/A could be protective variants against VTE in Indians. While MTHFR 677C/T mutation was found to be associated, in contrast to other populations, the established genetic variants FVL 1691G/A, prothrombin 20210G/A, and TFPI −536C/T may not be associated with VTE in Indians thus revealing the basis of ethnicity related differences in susceptibility of Indians to VTE.
Embryonic Development of Heart in Indian Buffalo (Bubalus bubalis)
Authors: Gupta Anuradha , Bansal Neelam , Uppal Varinder
Published: September 2014

The present study was conducted on 35 buffalo foetuses from 0.9 cm CVRL (32 days) to 99.5 cm CVRL (298 days) to observe the morphogenesis and histogenesis of heart. The study revealed that, in 0.9 cm CVRL buffalo foetus, heart was unseptated and tubular which was clearly divided into common atrial chamber dorsally, primitive ventricles ventrally, primitive outflow tract with bulbous cordis region proximally, and aortic sac distally at 1.2 cm CVRL. Septum primum appeared at 1.9 cm CVRL whereas the truncal swellings and fold of interventricular septum appeared at 2.5 cm CVRL foetus. At 3.0 cm CVRL septum primum, endocardial cushions, septum secundum, and foramen ovale were observed. At 7.6 cm CVRL the endocardial cushions fused to form right and left atrioventricular openings and ventricular apex became pointed. Interventricular canal was obliterated and four-chambered heart was recognised along with atrioventricular valve, chordae tendineae, and papillary muscles in 8.7 cm CVRL (66 days) buffalo foetus. The endocardium as well as epicardium of the atria was thicker as compared to ventricle, whereas the myocardium of atria was thin as compared to ventricles in all the age groups. All the internal structures of heart were well differentiated from 50 cm CVRL onwards. The detailed structural components of buffalo heart during prenatal period have been discussed in the present paper.
Impacts of Transportation Cost on Distribution‐Free Newsboy Problems
Authors: Shu Ming-Hung , Yeh Chun-Wu , Fu Yen-Chen
Published: September 2014

A distribution‐free newsboy problem (DFNP) has been launched for a vendor to decide a product’s stock quantity in a single‐period inventory system to sustain its least maximum‐expected profits when combating fierce and diverse market circumstances. Nowadays, impacts of transportation cost on determination of optimal inventory quantity have become attentive, where its influence on the DFNP has not been fully investigated. By borrowing an economic theory from transportation disciplines, in this paper the DFNP is tackled in consideration of the transportation cost formulated as a function of shipping quantity and modeled as a nonlinear regression form from UPS’s on‐site shipping‐rate data. An optimal solution of the order quantity is computed on the basis of Newton’s approach to ameliorating its complexity of computation. As a result of comparative studies, lower bounds of the maximal expected profit of our proposed methodologies surpass those of existing work. Finally, we extend the analysis to several practical inventory cases including fixed ordering cost, random yield, and a multiproduct condition.
A Comparative Assessment of Spalart‐Shur Rotation/Curvature Correction in RANS Simulations in a Centrifugal Pump Impeller
Authors: Tao Ran , Xiao Ruofu , Yang Wei , Wang Fujun
Published: September 2014

RANS simulation is widely used in the flow prediction of centrifugal pumps. Influenced by impeller rotation and streamline curvature, the eddy viscosity models with turbulence isotropy assumption are not accurate enough. In this study, Spalart‐Shur rotation/curvature correction was applied on the SST k‐ω turbulence model. The comparative assessment of the correction was proceeded in the simulations of a centrifugal pump impeller. CFD results were compared with existing PIV and LDV data under the design and low flow rate off‐design conditions. Results show the improvements of the simulation especially in the situation that turbulence strongly produced due to undesirable flow structures. Under the design condition, more reasonable turbulence kinetic energy contour was captured after correction. Under the low flow rate off‐design condition, the prediction of turbulence kinetic energy and velocity distributions became much more accurate when using the corrected model. So, the rotation/curvature correction was proved effective in this study. And, it is also proved acceptable and recommended to use in the engineering simulations of centrifugal pump impellers.
Analysis of the Results of Use of Bone Graft and Reconstruction Cages in a Group of Patients with Severe Acetabular Bone Defects
Authors: Toro-Ibarguen Ainhoa , Auñón-Martín Ismael , Delgado-Díaz Emilio , Moreno-Beamud Jose Alberto , Martínez-Leocadio Miguel Ángel , Díaz-Martín Andrés , Candel-García Luciano
Published: September 2014

Introduction. Rings and cages are indicated for use in revision total hip with severe bone loss. Material and Methods. A retrospective study was performed on 37 acetabular revision cases with an average age at revision of 67.8 years. According to Paprosky classification, 54% grade II and 46% grade III. We used two types of cages, Protrusio and Contour cage. We used 23 standard liners and 14 dual mobility cups. Results. The average follow-up was 5.4 years. The mean Merlé-d’Aubigné score improved from 5.48 to 10.5 points (P<0.05). There were 10 nerve palsies, 6 rings that lost fixation, 10 dislocations, and 4 infections. The need for reoperation for any reason rose to 32% (12/37). Success, defined as a stable reconstruction, was 73%. We found that, using a dual mobility cup cemented into the cage, the dislocation rate and revision rate came down (P<0.05). Conclusions. The treatment of severe acetabular defects using bone graft and reconstruction cages is a viable option. The use of a dual mobility cup cemented into the cage could avoid dislocations and the insertion of the ischial flap inside the ischial portion of the acetabulum for further ring stability and protection of the sciatic nerve.
Water Breakthrough Shape Description of Horizontal Wells in Bottom‐Water Reservoir
Authors: Huang Shijun , Zeng Baoquan , Zhao Fenglan , Cheng Linsong , Du Baojian
Published: September 2014

Horizontal wells have been applied in bottom‐water reservoir since their advantages were found on distribution of linear dropdown near wellbore, higher critical production, and more OOIP (original oil in place) controlled. In the paper, one 3D visible physical model of horizontal physical model is designed and built to simulate the water cresting process during the horizontal well producing and find water breakthrough point in homogenous and heterogeneous reservoir with bottom water. Water cresting shape and water cut of horizontal well in between homogenous and heterogeneous reservoir are compared on the base of experiment’s result. The water cresting pattern of horizontal well in homogeneous reservoir can be summarized as “central breakthrough, lateral expansion, thorough flooding, and then flank uplifting.” Furthermore, a simple analysis model of horizontal well in bottom water reservoir is established and water breakthrough point is analyzed. It can be drawn from the analysis result that whether or not to consider the top and bottom border, breakthrough would be located in the middle of horizontal segment with equal flow velocity distribution.
Performance Analysis for Distributed Fusion with Different Dimensional Data
Authors: Yuan Xianghui , Duan Zhansheng , Han Chongzhao
Published: September 2014

Different sensors or estimators may have different capability to provide data. Some sensors can provide a relatively higher dimensional data, while other sensors can only provide part of them. Some estimators can estimate full dimensional quantity of interest, while others may only estimate part of it due to some constraints. How is such kind of data with different dimensions fused? How do the common part and the uncommon part affect each other during fusion? To answer these questions, a fusion algorithm based on linear minimum mean‐square error (LMMSE) estimation is provided in this paper. Then the fusion performance is analyzed, which is the main contribution of this work. The conclusions are as follows. First, the fused common part is not affected by the uncommon part. Second, the fused uncommon part will benefit from the common part through the cross‐correlation. Finally, under certain conditions, both the more accurate common part and the stronger correlation can result in more accurate fused uncommon part. The conclusions are all supported by some tracking application examples.
A Third-Order Newton-Type Method for Finding Polar Decomposition
Authors: Khaksar Haghani F.
Published: September 2014

It is attempted to present an iteration method for finding polar decomposition. The approach is categorized in the scope of Newton-type methods. Error analysis and rate of convergence are studied. Some illustrations are also given to disclose the numerical behavior of the proposed method.
Sepsis Associated Encephalopathy
Authors: Chaudhry Neera , Duggal Ashish Kumar
Published: September 2014

Sepsis associated encephalopathy (SAE) is a common but poorly understood neurological complication of sepsis. It is characterized by diffuse brain dysfunction secondary to infection elsewhere in the body without overt CNS infection. The pathophysiology of SAE is complex and multifactorial including a number of intertwined mechanisms such as vascular damage, endothelial activation, breakdown of the blood brain barrier, altered brain signaling, brain inflammation, and apoptosis. Clinical presentation of SAE may range from mild symptoms such as malaise and concentration deficits to deep coma. The evaluation of cognitive dysfunction is made difficult by the absence of any specific investigations or biomarkers and the common use of sedation in critically ill patients. SAE thus remains diagnosis of exclusion which can only be made after ruling out other causes of altered mentation in a febrile, critically ill patient by appropriate investigations. In spite of high mortality rate, management of SAE is limited to treatment of the underlying infection and symptomatic treatment for delirium and seizures. It is important to be aware of this condition because SAE may present in early stages of sepsis, even before the diagnostic criteria for sepsis can be met. This review discusses the diagnostic approach to patients with SAE along with its epidemiology, pathophysiology, clinical presentation, and differential diagnosis.
Maximizing Lifetime of Wireless Sensor Networks with Mobile Sink Nodes
Authors: Chen Yourong , Wang Zhangquan , Ren Tiaojuan , Liu Yaolin , Lv Hexin
Published: September 2014

In order to maximize network lifetime and balance energy consumption when sink nodes can move, maximizing lifetime of wireless sensor networks with mobile sink nodes (MLMS) is researched. The movement path selection method of sink nodes is proposed. Modified subtractive clustering method, k‐means method, and nearest neighbor interpolation method are used to obtain the movement paths. The lifetime optimization model is established under flow constraint, energy consumption constraint, link transmission constraint, and other constraints. The model is solved from the perspective of static and mobile data gathering of sink nodes. Subgradient method is used to solve the lifetime optimization model when one sink node stays at one anchor location. Geometric method is used to evaluate the amount of gathering data when sink nodes are moving. Finally, all sensor nodes transmit data according to the optimal data transmission scheme. Sink nodes gather the data along the shortest movement paths. Simulation results show that MLMS can prolong network lifetime, balance node energy consumption, and reduce data gathering latency under appropriate parameters. Under certain conditions, it outperforms Ratio_w, TPGF, RCC, and GRND.
Estimating the Effectiveness of Health-Risk Communications with Propensity-Score Matching: Application to Arsenic Groundwater Contamination in Four US Locations
Authors: Leidner Andrew J.
Published: September 2014

This paper provides a demonstration of propensity-score matching estimation methods to evaluate the effectiveness of health-risk communication efforts. This study develops a two-stage regression model to investigate household and respondent characteristics as they contribute to aversion behavior to reduce exposure to arsenic-contaminated groundwater. The aversion activity under study is a household-level point-of-use filtration device. Since the acquisition of arsenic contamination information and the engagement in an aversion activity may be codetermined, a two-stage propensity-score model is developed. In the first stage, the propensity for households to acquire arsenic contamination information is estimated. Then, the propensity scores are used to weight observations in a probit regression on the decision to avert the arsenic-related health risk. Of four potential sources of information, utility, media, friend, or others, information received from a friend appears to be the source of information most associated with aversion behavior. Other statistically significant covariates in the household’s decision to avert contamination include reported household income, the presence of children in household, and region-level indicator variables. These findings are primarily illustrative and demonstrate the usefulness of propensity-score methods to estimate health-risk communication effectiveness. They may also be suggestive of areas for future research.
Statistical Analysis of Nonlinear Processes Based on Penalty Factor
Authors: Zhang Yingwei , Zhang Chuanfang , Zhang Wei
Published: September 2014

A new process monitoring approach is proposed for handling the nonlinear monitoring problem in the electrofused magnesia furnace (EFMF). Compared to conventional method, the contributions are as follows: (1) a new kernel principal component analysis is proposed based on loss function in the feature space; (2) the model of kernel principal component analysis based on forgetting factor is updated; (3) a new iterative kernel principal component analysis algorithm is proposed based on penalty factor.