bluuebunny/crossref_metadata_2025 huggingface dataset:
Syntaxin‐binding domain of Kv2.1 is essential for the expression of apoptotic K+ currents
Authors: McCord Meghan C. , Kullmann Paul H. , He Kai , Hartnett Karen A. , Horn John P. , Lotan Ilana , Aizenman Elias
Published: June 2014

Key points

K+ efflux through newly membrane‐inserted voltage‐gated Kv2.1 K+ channels precedes neuronal apoptosis.

In this study, we show that the binding site of the soluble N‐ethylmaleimide‐sensitive factor attachment protein receptor (SNARE) protein syntaxin on Kv2.1 (a 110 amino acid C‐terminal domain of Kv2.1, termed C1a) is required for the enhancement of apoptotic K+ currents.

Expression of a Kv2.1‐derived C1a peptide prevents Kv2.1/syntaxin binding, oxidant‐induced, enhanced K+ currents and cell death without substantially affecting electrical properties of neurons.

Data suggest that syntaxin binds within the most distal 50 amino acids of the C1a domain of Kv2.1.

Disrupting Kv2.1/syntaxin binding may represent a new tactic for suppressing injurious K+ efflux, which is a ubiquitous requirement of apoptotic signalling cascades in neurons.

Intracellular signalling cascades triggered by oxidative injury can lead to upregulation of Kv2.1 K+ channels at the plasma membrane of dying neurons. Membrane incorporation of new channels is necessary for enhanced K+ efflux and a consequent reduction of intracellular K+ that facilitates apoptosis. We showed previously that the observed increase in K+ currents is a soluble N‐ethylmaleimide‐sensitive factor attachment protein receptor (SNARE)‐mediated process, and that the SNARE protein syntaxin binds directly to Kv2.1 channels. In the present study, we tested whether disrupting the interaction of Kv2.1 and syntaxin promoted the survival of cortical neurons following injury. Syntaxin is known to bind to Kv2.1 in a domain comprising amino acids 411–522 of the channel's cytoplasmic C terminus (C1a). Here we show that this domain is required for the apoptotic K+ current enhancement. Moreover, expression of an isolated, Kv2.1‐derived C1a peptide is sufficient to suppress the injury‐induced increase in currents by interfering with Kv2.1/syntaxin binding. By subdividing the C1a peptide, we were able to localize the syntaxin binding site on Kv2.1 to the most plasma membrane‐distal residues of C1a. Importantly, expression of this peptide segment in neurons prevented the apoptotic K+ current enhancement and cell death following an oxidative insult, without greatly impairing baseline K+ currents or normal electrical profiles of neurons. These results establish that binding of syntaxin to Kv2.1 is crucial for the manifestation of oxidant‐induced apoptosis, and thereby reveal a potential new direction for therapeutic intervention in the treatment of neurodegenerative disorders.
RANS Modeling of Accelerating Boundary Layers
Authors: Oriji Ugochukwu R. , Karimisani Sahand , Tucker Paul G.
Published: June 2014

A numerical investigation of accelerated boundary layers (BL) has been performed using linear and nonlinear eddy viscosity models (EVM). The acceleration parameters (KS) investigated the range between 1.5 × 10−6 and 3.0 × 10−6. The one-equation (k-l), Spalart Allmaras (SA), and the two-equation Menter Shear Stress Transport (SST) and Chien models in their standard forms are found to be insensitive to acceleration. Nevertheless, proposed modifications for the SA, Chien, and the k-l models significantly improved predictions. The major improvement was achieved by modifying the damping functions in these models and also an analogous source term, E, for the Chien model. Encouraging agreement with measurements is found using the Launder Sharma (LS), cubic and explicit algebraic stress models (EASM) in their standard forms. The cubic model best predicted the turbulence quantities. Investigations confirm that it is practical for Reynolds-Average Navier–Stokes (RANS) models to capture reversion from the turbulent to laminar state albeit for equilibrium sink type flows.
Fatigue Design Load Identification Using Engineering Data Analytics
Authors: Bae Ha-Rok , Ando Hiroaki , Nam Sangjeong , Kim Sangkyum , Ha Christopher
Published: June 2014

Selecting an appropriate concept design in the early stage of the product development process is crucial for successful machine development. As one of the important design requirements, a structural design needs to validate the structural fatigue life against physical tests of actual field operations. Traditionally, the fatigue design loads for the concept design evaluations are generated by hand calculations based on past experience to capture envelopes of expected system responses. But such an approach often does not capture actual loading behaviors in the field. An alternative approach of leveraging observed data from physical tests is highly desired, and a new method of this approach is introduced in this study. Our goal is to develop a new methodology of identifying fundamental fatigue load (FFL) contents from observed data by using engineering data analytics (EDA) techniques. The proposed methodology is applied to determine a new sensor layout which enables us to capture fundamental structural damage load patterns. Numerical demonstrations and case studies of the proposed method are presented with a common structural component, an I-section cantilever beam, and an industrial large-scale structure, a front linkage of a hydraulic excavator.
A New Stabilization Algorithm for a Two-Wheeled Mobile Robot Aided by Reaction Wheel
Authors: Reza Larimi S. , Zarafshan Payam , Moosavian S. Ali A.
Published: June 2014

The concept of two-wheeled mobile manipulator (TWMM) has been proposed for its significant advantage due to high maneuverability particularly in confined internal spaces. However, its unbalanced structure imposes restrictions for widespread application. Note that the nonholonomic property of a TWMM makes its control a more challenging task. In this paper, a new stabilization mechanism of TWMM is presented, and a new control method based on dynamical balancing algorithm is proposed that could effectively resolve those restrictions. To this end, a reaction wheel is considered to control the position of center of gravity (COG), leading to a smoother motion of the robot manipulator. To make the robot be able to manipulate an object, a double inverted pendulum model (DIPM) is considered as a simplified model of the system. DIPM dynamics is used to identify and simplify the dynamics of TWMM and subsequently a supervisory control is employed to stabilize the robot via its COG position. This in turn improves the robustness of the proposed algorithm during manipulation maneuver of an object with unknown mass parameters. Results are compared to those of an ideal model-based algorithm that reveal the merits of the proposed control strategy.
Microbial Successions Are Associated with Changes in Chemical Profiles of a Model Refrigerated Fresh Pork Sausage during an 80-Day Shelf Life Study
Authors: Benson Andrew K. , David Jairus R. D. , Gilbreth Stefanie Evans , Smith Gordon , Nietfeldt Joseph , Legge Ryan , Kim Jaehyoung , Sinha Rohita , Duncan Christopher E. , Ma Junjie , Singh Indarpal
Published: June 2014

Fresh pork sausage is produced without a microbial kill step and therefore chilled or frozen to control microbial growth. In this report, the microbiota in a chilled fresh pork sausage model produced with or without an antimicrobial combination of sodium lactate and sodium diacetate was studied using a combination of traditional microbiological methods and deep pyrosequencing of 16S rRNA gene amplicons. In the untreated system, microbial populations rose from 10
2
to 10
6
CFU/g within 15 days of storage at 4°C, peaking at nearly 10
8
CFU/g by day 30. Pyrosequencing revealed a complex community at day 0, with taxa belonging to the
Bacilli
,
Gammaproteobacteria
,
Betaproteobacteria
,
Actinobacteria
,
Bacteroidetes
, and
Clostridia
. During storage at 4°C, the untreated system displayed a complex succession, with species of
Weissella
and
Leuconostoc
that dominate the product at day 0 being displaced by species of
Pseudomonas
(
P. lini
and
P. psychrophila
) within 15 days. By day 30, a second wave of taxa (
Lactobacillus graminis
,
Carnobacterium divergens
,
Buttiauxella brennerae
,
Yersinia mollaretti
, and a taxon of
Serratia
) dominated the population, and this succession coincided with significant chemical changes in the matrix. Treatment with lactate-diacetate altered the dynamics dramatically, yielding a monophasic growth curve of a single species of
Lactobacillus
(
L. graminis
), followed by a uniform selective die-off of the majority of species in the population. Of the six species of
Lactobacillus
that were routinely detected,
L. graminis
became the dominant member in all samples, and its origins were traced to the spice blend used in the formulation.
Uptake and Metabolism of
N
-Acetylglucosamine and Glucosamine by Streptococcus mutans
Authors: Moye Zachary D. , Burne Robert A. , Zeng Lin
Published: June 2014

Glucosamine and
N
-acetylglucosamine are among the most abundant sugars on the planet, and their introduction into the oral cavity via the diet and host secretions, and through bacterial biosynthesis, provides oral biofilm bacteria with a source of carbon, nitrogen, and energy. In this study, we demonstrated that the dental caries pathogen
Streptococcus mutans
possesses an inducible system for the metabolism of
N
-acetylglucosamine and glucosamine. These amino sugars are transported by the phosphoenolpyruvate:sugar phosphotransferase system (PTS), with the glucose/mannose enzyme II permease encoded by
manLMN
playing a dominant role. Additionally, a previously uncharacterized gene product encoded downstream of the
manLMN
operon, ManO, was shown to influence the efficiency of uptake and growth on
N
-acetylglucosamine and, to a lesser extent, glucosamine. A transcriptional regulator, designated NagR, was able to bind the promoter regions
in vitro
, and repress the expression
in vivo
, of the
nagA
and
nagB
genes, encoding
N
-acetylglucosamine-6-phosphate deacetylase and glucosamine-6-phosphate deaminase, respectively. The binding activity of NagR could be inhibited by glucosamine-6-phosphate
in vitro
. Importantly, in contrast to the case with certain other
Firmicutes
, the gene for
de novo
synthesis of glucosamine-6-phosphate in
S. mutans
,
glmS
, was also shown to be regulated by NagR, and NagR could bind the
glmS
promoter region
in vitro
. Finally, metabolism of these amino sugars by
S. mutans
resulted in the production of significant quantities of ammonia, which can neutralize cytoplasmic pH and increase acid tolerance, thus contributing to enhanced persistence and pathogenic potential.
Epithelial Adhesion Mediated by Pilin SpaC Is Required for Lactobacillus rhamnosus GG-Induced Cellular Responses
Authors: Ardita Courtney S. , Mercante Jeffrey W. , Kwon Young Man , Luo Liping , Crawford Madelyn E. , Powell Domonica N. , Jones Rheinallt M. , Neish Andrew S.
Published: June 2014

Lactobacillus rhamnosus
GG is a widely used probiotic, and the strain's salutary effects on the intestine have been extensively documented. We previously reported that strain GG can modulate inflammatory signaling, as well as epithelial migration and proliferation, by activating NADPH oxidase 1-catalyzed generation of reactive oxygen species (ROS). However, how strain GG induces these responses is unknown. Here, we report that strain GG's probiotic benefits are dependent on the bacterial-epithelial interaction mediated by the SpaC pilin subunit. By comparing strain GG to an isogenic mutant that lacks SpaC (strain GGΩ
spaC
), we establish that SpaC is necessary for strain GG to adhere to gut mucosa, that SpaC contributes to strain GG-induced epithelial generation of ROS, and that SpaC plays a role in strain GG's capacity to stimulate extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) signaling in enterocytes. In addition, we show that SpaC is required for strain GG-mediated stimulation of cell proliferation and protection against radiologically inflicted intestinal injury. The identification of a critical surface protein required for strain GG to mediate its probiotic influence advances our understanding of the molecular basis for the symbiotic relationship between some commensal bacteria of the gut lumen and enterocytes. Further insights into this relationship are critical for the development of novel approaches to treat intestinal diseases.
Following Pathogen Development and Gene Expression in a Food Ecosystem: the Case of a Staphylococcus aureus Isolate in Cheese
Authors: Fleurot Isabelle , Aigle Marina , Fleurot Renaud , Darrigo Claire , Hennekinne Jacques-Antoine , Gruss Alexandra , Borezée-Durant Elise , Delacroix-Buchet Agnès
Published: June 2014

Human intoxication or infection due to bacterial food contamination constitutes an economic challenge and a public health problem. Information on the
in situ
distribution and expression of pathogens responsible for this risk is to date lacking, largely because of technical bottlenecks in detecting signals from minority bacterial populations within a complex microbial and physicochemical ecosystem. We simulated the contamination of a real high-risk cheese with a natural food isolate of
Staphylococcus aureus
, an enterotoxin-producing pathogen responsible for food poisoning. To overcome the problem of a detection limit in a solid matrix, we chose to work with a fluorescent reporter (superfolder green fluorescent protein) that would allow spatiotemporal monitoring of
S. aureus
populations and targeted gene expression. The combination of complementary techniques revealed that
S. aureus
localizes preferentially on the cheese surface during ripening. Immunochemistry and confocal laser scanning microscopy enabled us to visualize, in a single image, dairy bacteria and pathogen populations, virulence gene expression, and the toxin produced. This procedure is readily applicable to other genes of interest, other bacteria, and different types of food matrices.
Daily Expression Pattern of Protein-Encoding Genes and Small Noncoding RNAs in Synechocystis sp. Strain PCC 6803
Authors: Beck Christian , Hertel Stefanie , Rediger Anne , Lehmann Robert , Wiegard Anika , Kölsch Adrian , Heilmann Beate , Georg Jens , Hess Wolfgang R. , Axmann Ilka M.
Published: June 2014

Many organisms harbor circadian clocks with periods close to 24 h. These cellular clocks allow organisms to anticipate the environmental cycles of day and night by synchronizing circadian rhythms with the rising and setting of the sun. These rhythms originate from the oscillator components of circadian clocks and control global gene expression and various cellular processes. The oscillator of photosynthetic cyanobacteria is composed of three proteins, KaiA, KaiB, and KaiC, linked to a complex regulatory network.
Synechocystis
sp. strain PCC 6803 possesses the standard cyanobacterial
kaiABC
gene cluster plus multiple
kaiB
and
kaiC
gene copies and antisense RNAs for almost every
kai
transcript. However, there is no clear evidence of circadian rhythms in
Synechocystis
sp. PCC 6803 under various experimental conditions. It is also still unknown if and to what extent the multiple
kai
gene copies and
kai
antisense RNAs affect circadian timing. Moreover, a large number of small noncoding RNAs whose accumulation dynamics over time have not yet been monitored are known for
Synechocystis
sp. PCC 6803. Here we performed a 48-h time series transcriptome analysis of
Synechocystis
sp. PCC 6803, taking into account periodic light-dark phases, continuous light, and continuous darkness. We found that expression of functionally related genes occurred in different phases of day and night. Moreover, we found day-peaking and night-peaking transcripts among the small RNAs; in particular, the amounts of
kai
antisense RNAs correlated or anticorrelated with those of their respective
kai
target mRNAs, pointing toward the regulatory relevance of these antisense RNAs. Surprisingly, we observed that the amounts of 16S and 23S rRNAs in this cyanobacterium fluctuated in light-dark periods, showing maximum accumulation in the dark phase. Importantly, the amounts of all transcripts, including small noncoding RNAs, did not show any rhythm under continuous light or darkness, indicating the absence of circadian rhythms in
Synechocystis
.
Identification of Mn(II)-Oxidizing Bacteria from a Low-pH Contaminated Former Uranium Mine
Authors: Akob Denise M. , Bohu Tsing , Beyer Andrea , Schäffner Franziska , Händel Matthias , Johnson Carol A. , Merten Dirk , Büchel Georg , Totsche Kai Uwe , Küsel Kirsten
Published: June 2014

Biological Mn oxidation is responsible for producing highly reactive and abundant Mn oxide phases in the environment that can mitigate metal contamination. However, little is known about Mn oxidation in low-pH environments, where metal contamination often is a problem as the result of mining activities. We isolated two Mn(II)-oxidizing bacteria (MOB) at pH 5.5 (Duganellaisolate AB_14 andAlbidiferaxisolate TB-2) and nine strains at pH 7 from a former uranium mining site. Isolate TB-2 may contribute to Mn oxidation in the acidic Mn-rich subsoil, as a closely related clone represented 16% of the total community. All isolates oxidized Mn over a small pH range, and isolates from low-pH samples only oxidized Mn below pH 6. Two strains with different pH optima differed in their Fe requirements for Mn oxidation, suggesting that Mn oxidation by the strain found at neutral pH was linked to Fe oxidation. Isolates tolerated Ni, Cu, and Cd and produced Mn oxides with similarities to todorokite and birnessite, with the latter being present in subsurface layers where metal enrichment was associated with Mn oxides. This demonstrates that MOB can be involved in the formation of biogenic Mn oxides in both moderately acidic and neutral pH environments.
DegePrime, a Program for Degenerate Primer Design for Broad-Taxonomic-Range PCR in Microbial Ecology Studies
Authors: Hugerth Luisa W. , Wefer Hugo A. , Lundin Sverker , Jakobsson Hedvig E. , Lindberg Mathilda , Rodin Sandra , Engstrand Lars , Andersson Anders F.
Published: June 2014

The taxonomic composition of a microbial community can be deduced by analyzing its rRNA gene content by, e.g., high-throughput DNA sequencing or DNA chips. Such methods typically are based on PCR amplification of rRNA gene sequences using broad-taxonomic-range PCR primers. In these analyses, the use of optimal primers is crucial for achieving an unbiased representation of community composition. Here, we present the computer program DegePrime that, for each position of a multiple sequence alignment, finds a degenerate oligomer of as high coverage as possible and outputs its coverage among taxonomic divisions. We show that our novel heuristic, which we call weighted randomized combination, performs better than previously described algorithms for solving the maximum coverage degenerate primer design problem. We previously used DegePrime to design a broad-taxonomic-range primer pair that targets the bacterial V3-V4 region (341F-805R) (D. P. Herlemann, M. Labrenz, K. Jurgens, S. Bertilsson, J. J. Waniek, and A. F. Andersson, ISME J. 5:1571–1579, 2011,
http://dx.doi.org/10.1038/ismej.2011.41
), and here we use the program to significantly increase the coverage of a primer pair (515F-806R) widely used for Illumina-based surveys of bacterial and archaeal diversity. By comparison with shotgun metagenomics, we show that the primers give an accurate representation of microbial diversity in natural samples.
Modeling Bacterial Population Growth from Stochastic Single-Cell Dynamics
Authors: Alonso Antonio A. , Molina Ignacio , Theodoropoulos Constantinos
Published: June 2014

A few bacterial cells may be sufficient to produce a food-borne illness outbreak, provided that they are capable of adapting and proliferating on a food matrix. This is why any quantitative health risk assessment policy must incorporate methods to accurately predict the growth of bacterial populations from a small number of pathogens. In this aim, mathematical models have become a powerful tool. Unfortunately, at low cell concentrations, standard deterministic models fail to predict the fate of the population, essentially because the heterogeneity between individuals becomes relevant. In this work, a stochastic differential equation (SDE) model is proposed to describe variability within single-cell growth and division and to simulate population growth from a given initial number of individuals. We provide evidence of the model ability to explain the observed distributions of times to division, including the lag time produced by the adaptation to the environment, by comparing model predictions with experiments from the literature for
Escherichia coli
,
Listeria innocua
, and
Salmonella enterica
. The model is shown to accurately predict experimental growth population dynamics for both small and large microbial populations. The use of stochastic models for the estimation of parameters to successfully fit experimental data is a particularly challenging problem. For instance, if Monte Carlo methods are employed to model the required distributions of times to division, the parameter estimation problem can become numerically intractable. We overcame this limitation by converting the stochastic description to a partial differential equation (backward Kolmogorov) instead, which relates to the distribution of division times. Contrary to previous stochastic formulations based on random parameters, the present model is capable of explaining the variability observed in populations that result from the growth of a small number of initial cells as well as the lack of it compared to populations initiated by a larger number of individuals, where the random effects become negligible.
BEM46 Shows Eisosomal Localization and Association with Tryptophan-Derived Auxin Pathway in Neurospora crassa
Authors: Kollath-Leiß K. , Bönniger C. , Sardar P. , Kempken F.
Published: June 2014

BEM46 proteins are evolutionarily conserved, but their functions remain elusive. We reported previously that the BEM46 protein inNeurospora crassais targeted to the endoplasmic reticulum (ER) and is essential for ascospore germination. In the present study, we established abem46knockout strain ofN. crassa. This Δbem46mutant exhibited a level of ascospore germination lower than that of the wild type but much higher than those of the previously characterizedbem46-overexpressing and RNA interference (RNAi) lines. Reinvestigation of the RNAi transformants revealed two types of alternatively splicedbem46mRNA; expression of either type led to a loss of ascospore germination. Our results indicated that the phenotype was not due tobem46mRNA downregulation or loss but was caused by the alternatively spliced mRNAs and the peptides they encoded. Using theN. crassaortholog of the eisosomal protein PILA fromAspergillus nidulans, we further demonstrated the colocalization of BEM46 with eisosomes. Employing the yeast two-hybrid system, we identified a single interaction partner: anthranilate synthase component II (encoded bytrp-1). This interaction was confirmedin vivoby a split-YFP (yellow fluorescent protein) approach. The Δtrp-1mutant showed reduced ascospore germination and increased indole production, and we used bioinformatic tools to identify a putative auxin biosynthetic pathway. The genes involved exhibited various levels of transcriptional regulation in the differentbem46transformant and mutant strains. We also investigated the indole production of the strains in different developmental stages. Our findings suggested that the regulation of indole biosynthesis genes was influenced bybem46overexpression. Furthermore, we uncovered evidence of colocalization of BEM46 with the neutral amino acid transporter MTR.
The effect of coach and player injury knowledge, attitudes and beliefs on adherence to the FIFA 11+ programme in female youth soccer
Authors: McKay Carly D , Steffen Kathrin , Romiti Maria , Finch Caroline F , Emery Carolyn A
Published: June 2014

Background

Injury knowledge and beliefs influence uptake of prevention programmes, but the relationship between knowledge, beliefs and adherence remains unclear.

Aim

To describe injury knowledge and beliefs among youth female soccer coaches and players, and to identify the relationship between these factors, different delivery strategies of the FIFA 11+ programme and adherence.

Methods

A subcohort analysis from a cluster-randomised controlled trial of 31 female soccer teams (coaches n=29, players (ages 13–18) n=258). Preseason and postseason questionnaires were used to assess knowledge and beliefs. Teams recorded FIFA 11+ adherence during the season.

Results

At baseline, 62.8% (95% CI 48.4% to 77.3%) of coaches and 75.8% (95% CI 71.5% to 80.1%) of players considered ‘inadequate warm-up’ a risk factor for injury. There was no effect of delivery method (OR=1.1; 95% CI 0.8 to 1.5) or adherence (OR=1.0; 95% CI 0.9 to 1.1) on this belief. At baseline, 13.8% (95% CI 1.3% to 26.4%) of coaches believed a warm-up could prevent muscle injuries, but none believed it could prevent knee and ankle injuries. For players, 9.7% (95% CI 6.1% to 13.3%), 4.7% (95% CI 2.1% to 7.3%) and 4.7% (95% CI 2.1% to 7.3%) believed a warm-up would prevent muscle, knee and ankle injuries, respectively. Years of playing experience were negatively associated with high adherence for coaches (OR=0.93; 0.88 to 0.99) and players (OR=0.92; 0.85 to 0.98).

Conclusions

There were gaps in injury knowledge and beliefs, which differed for coaches and players. Beliefs did not significantly affect adherence to the FIFA 11+, suggesting additional motivational factors should be considered.
Efficient sampling strategies for forest inventories by spreading the sample in auxiliary space
Authors: Grafström Anton , Saarela Svetlana , Ene Liviu Theodor
Published: June 2014

By using more sophisticated sampling designs in forest field inventories, it is possible to select more representative field samples. When full cover auxiliary information is available at the planning stage of a forest inventory, an efficient strategy for sampling is formed by making sure that the sample is well spread in the space spanned by the auxiliary variables. We show that by using such a sampling design, we can improve not only design-based estimation, but also estimation based on nearest neighbour techniques. A new technique to select well-spread probability samples, in multidimensional spaces, from larger populations is introduced. As an application, we illustrate how this strategy can be applied to a forest field inventory. We use an artificial dataset corresponding to a full cover forest remote sensing inventory of a 30 000 ha area of Kuortane, western Finland. The target variable (growing stock volume) has been generated for the entire area by a copula technique. The artificial population has been validated by utilizing the Finnish National Forest Inventory.
A flexible software design to determine the plasma boundary in Damavand tokamak
Authors: Ghadiri Rasoul , Sadeghi Yahya , Esteki Mohammad Hossein
Published: June 2014

A plasma boundary reconstruction code has been designed by using current filament method to calculate the magnetic flux and consequently plasma boundary in Damavand tokamak. Hence, a computer-based code "The Plasma Boundary Reconstruction Code in Tokamak (PBRCT)" was developed to make a graphical user interface and to speed up the plasma boundary estimation algorithm. All required tools as the plasma boundary and magnetic surface display (MSD), error display, primary conditions and modeling panel as well as a search motor to determine a good position and number of the current filaments to find a precise model have been considered. The core is a 3000 lines Matlab code and the graphical user interface is 10,000 lines in C# language.
Axisymmetric Wave Propagation in Uniform Gas Flow Confined by Rigid-Walled Pipeline
Authors: Chen Yong , Huang Yiyong , Chen Xiaoqian , Hu Dengpeng
Published: June 2014

This paper deals with the axisymmetric acoustic wave propagating along the perfect gas in the presence of a uniform flow confined by a rigid-walled pipeline. Under the linear acoustic assumption, mathematical formulation of wave propagation is deduced from the conservations of mass, momentum and energy. Meanwhile a method based on the Fourier–Bessel theory is introduced to solve the problem. Comprehensive comparisons of the phase velocity and wave attenuation between the non-isentropic and isentropic acoustic waves are provided. Meanwhile the effects of flow profile, acoustic frequency, and pipeline radius are analyzed.
On Compatibility of Interval Multiplicative Preference Relations Based on the COWGA Operator
Authors: Zhou Ligang , He Yingdong , Chen Huayou , Liu Jinpei
Published: June 2014

The aim of this paper is to develop a new compatibility, which is very suitable to deal with group decision making (GDM) problems involving interval multiplicative preference relations, based on the continuous ordered weighted geometric averaging (COWGA) operator. First, we define some concepts of the compatibility degree and the compatibility index for the two interval multiplicative preference relations based on the COWGA operator. Then, we study some desirable properties of the compatibility index and investigate the relationship between each expert's interval multiplicative preference relation and the synthetic interval multiplicative preference relation. The prominent characteristic of the compatibility index based on the COWGA operator is that it can deal with the compatibility of all the arguments in two interval arguments considering the risk attitude of decision maker rather than the compatibility of the two simple points in intervals. Second, in order to determine the experts' weights in the GDM with the interval multiplicative preference relations, we propose an optimal model based on the criterion of minimizing the compatibility index. Finally, we give a numerical example to develop the new approach to GDM with interval multiplicative preference relations.
Enhanced photoluminescence of antiferroelectric liquid crystals doped with sodium titanate nanoparticles
Authors: Roy J. S. , Majumder T. P. , Dąbrowski R.
Published: June 2014

We have observed the enhancement in photoluminescence (PL) intensity of the antiferroelectric liquid crystals (AFLC) doped with Sodium titanate nanoparticles (NPs). The enhancement in PL intensity of AFLC strongly depends on the doping concentration of NPs. The Sodium titanate NPs were prepared such that the emission from NPs together with AFLC molecules gives enhanced PL intensity. On the other hand, smectic CA* phase of AFLC provides strong light scattering and hence incident photons get scattered to excite more NPs and give enhanced PL counts. We have also observed the shift in emission energy band of AFLC doped with NPs.
Artery buckling stimulates cell proliferation and NF-κB signaling
Authors: Xiao Yangming , Hayman Danika , Khalafvand Seyed Saeid , Lindsey Merry L. , Han Hai-Chao
Published: June 2014

Tortuous carotid arteries are often seen in aged populations and are associated with atherosclerosis, but the underlying mechanisms to explain this preference are unclear. Artery buckling has been suggested as one potential mechanism for the development of tortuous arteries. The objective of this study, accordingly, was to determine the effect of buckling on cell proliferation and associated NF-κB activation in arteries. We developed a technique to generate buckling in porcine carotid arteries using long artery segments in organ culture without changing the pressure, flow rate, and axial stretch ratio. Using this technique, we examined the effect of buckling on arterial wall remodeling in 4-day organ culture under normal and hypertensive pressures. Cell proliferation, NF-κB p65, IκB-α, ERK1/2, and caspase-3 were detected using immunohistochemistry staining and immunoblot analysis. Our results showed that cell proliferation was elevated 5.8-fold in the buckling group under hypertensive pressure ( n = 7, P < 0.01) with higher levels of NF-κB nuclear translocation and IκB-α degradation ( P < 0.05 for both). Greater numbers of proliferating cells were observed on the inner curve side of the buckled arteries compared with the outer curve side ( P < 0.01). NF-κB colocalized with proliferative nuclei. Computational simulations using a fluid-structure interaction model showed reduced wall stress on the inner side of buckled arteries and elevated wall stress on the outer side. We conclude that arterial buckling promotes site-specific wall remodeling with increased cell proliferation and NF-κB activation. These findings shed light on the biomechanical and molecular mechanisms of the pathogenesis of atherosclerosis in tortuous arteries.
β2-Adrenoreceptor blockade improves early posttrauma hyperglycemia and pulmonary injury in obese rats
Authors: Xiang Lusha , Lu Silu , Mittwede Peter N. , Clemmer John S. , Husband Graham W. , Hester Robert L.
Published: June 2014

Early hyperglycemia after trauma increases morbidity and mortality. Insulin is widely used to control posttrauma glucose, but this treatment increases the risk of hypoglycemia. We tested a novel method for early posttrauma hyperglycemia control by suppressing hepatic glycogenolysis via β2-adrenoreceptor blockade [ICI-118551 (ICI)]. We have shown that, after severe trauma, obese Zucker (OZ) rats, similar to obese patients, exhibit increased acute lung injury compared with lean Zucker (LZ) rats. We hypothesized that OZ rats exhibit a greater increase in early posttrauma glucose compared with LZ rats, with the increased posttrauma hyperglycemia suppressed by ICI treatment. Orthopedic trauma was applied to both hindlimbs in LZ and OZ rats. Fasting plasma glucose was then monitored for 6 h with or without ICI (0.2 mg·kg−1·h−1iv.) treatment. One day after trauma, plasma IL-6 levels, lung neutrophil numbers, myeloperoxidase (MPO) activity, and wet-to-dry weight ratios were measured. Trauma induced rapid hepatic glycogenolysis, as evidenced by decreased liver glycogen levels, and this was inhibited by ICI treatment. Compared with LZ rats, OZ rats exhibited higher posttrauma glucose, IL-6, lung neutrophil infiltration, and MPO activity. Lung wet-to-dry weight ratios were increased in OZ rats but not in LZ rats. ICI treatment reduced the early hyperglycemia, lung neutrophil retention, MPO activity, and wet-to-dry weight ratio in OZ rats to levels comparable with those seen in LZ rats, with no effect on blood pressure or heart rate. These results demonstrate that β2-adrenoreceptor blockade effectively reduces the early posttrauma hyperglycemia, which is associated with decreased lung injury in OZ rats.
Pleiotropic effects of the dipeptidylpeptidase-4 inhibitors on the cardiovascular system
Authors: Aroor Annayya R. , Sowers James R. , Jia Guanghong , DeMarco Vincent G.
Published: June 2014

Dipeptidylpeptidase-4 (DPP-4) is a ubiquitously expressed transmembrane protein that removes NH2-terminal dipeptides from various substrate hormones, chemokines, neuropeptides, and growth factors. Two known substrates of DPP-4 include the incretin hormones glucagon-like peptide-1 (GLP-1) and gastric inhibitory peptide, which are secreted by enteroendocrine cells in response to postprandial hyperglycemia and account for 60–70% of postprandial insulin secretion. DPP-4 inhibitors (DPP-4i) block degradation of GLP-1 and gastric inhibitory peptide, extend their insulinotropic effect, and improve glycemia. Since 2006, several DPP-4i have become available for treatment of type 2 diabetes mellitus. Clinical trials confirm that DPP-4i raises GLP-1 levels in plasma and improves glycemia with very low risk for hypoglycemia and other side effects. Recent studies also suggest that DPP-4i confers cardiovascular and kidney protection, beyond glycemic control, which may reduce the risk for further development of the multiple comorbidities associated with obesity/type 2 diabetes mellitus, including hypertension and cardiovascular disease (CVD) and kidney disease. The notion that DPP-4i may improve CVD outcomes by mechanisms beyond glycemic control is due to both GLP-1-dependent and GLP-1-independent effects. The CVD protective effects by DPP-4i result from multiple factors including insulin resistance, oxidative stress, dyslipidemia, adipose tissue dysfunction, dysfunctional immunity, and antiapoptotic properties of these agents in the heart and vasculature. This review focuses on cellular and molecular mechanisms mediating the CVD protective effects of DPP-4i beyond favorable effects on glycemic control.
Ambient and household air pollution: complex triggers of disease
Authors: Farmer Stephen A. , Nelin Timothy D. , Falvo Michael J. , Wold Loren E.
Published: June 2014

Concentrations of outdoor air pollution are on the rise, particularly due to rapid urbanization worldwide. Alternatively, poor ventilation, cigarette smoke, and other toxic chemicals contribute to rising concentrations of indoor air pollution. The World Health Organization recently reported that deaths attributable to indoor and outdoor air pollutant exposure are more than double what was originally documented. Epidemiological, clinical, and animal data have demonstrated a clear connection between rising concentrations of air pollution (both indoor and outdoor) and a host of adverse health effects. During the past five years, animal, clinical, and epidemiological studies have explored the adverse health effects associated with exposure to both indoor and outdoor air pollutants throughout the various stages of life. This review provides a summary of the detrimental effects of air pollution through examination of current animal, clinical, and epidemiological studies and exposure during three different periods: maternal (in utero), early life, and adulthood. Additionally, we recommend future lines of research while suggesting conceivable strategies to curb exposure to indoor and outdoor air pollutants.
Neural programming of mesenteric and renal arteries
Authors: Reho John J. , Zheng Xiaoxu , Benjamin James E. , Fisher Steven A.
Published: June 2014

There is evidence for developmental origins of vascular dysfunction yet little understanding of maturation of vascular smooth muscle (VSM) of regional circulations. We measured maturational changes in expression of myosin phosphatase (MP) and the broader VSM gene program in relation to mesenteric small resistance artery (SRA) function. We then tested the role of the sympathetic nervous system (SNS) in programming of SRAs and used genetically engineered mice to define the role of MP isoforms in the functional maturation of the mesenteric circulation. Maturation of rat mesenteric SRAs as measured by qPCR and immunoblotting begins after the second postnatal week and is not complete until maturity. It is characterized by induction of markers of VSM differentiation (smMHC, γ-, α-actin), CPI-17, an inhibitory subunit of MP and a key target of α-adrenergic vasoconstriction, α1-adrenergic, purinergic X1, and neuropeptide Y1 receptors of sympathetic signaling. Functional correlates include maturational increases in α-adrenergic-mediated force and calcium sensitization of force production (MP inhibition) measured in first-order mesenteric arteries ex vivo. The MP regulatory subunit Mypt1 E24+/LZ- isoform is specifically upregulated in SRAs during maturation. Conditional deletion of mouse Mypt1 E24 demonstrates that splicing of E24 causes the maturational reduction in sensitivity to cGMP-mediated vasorelaxation (MP activation). Neonatal chemical sympathectomy (6-hydroxydopamine) suppresses maturation of SRAs with minimal effect on a conduit artery. Mechanical denervation of the mature rat renal artery causes a reversion to the immature gene program. We conclude that the SNS captures control of the mesenteric circulation by programming maturation of the SRA smooth muscle.
Experimental Investigation on Thermoelectric Chiller Driven by Solar Cell
Authors: Chen Yen-Lin , Chien Zi-Jie , Lee Wen-Shing , Jwo Ching-Song , Cho Kun-Ching
Published: June 2014

This paper presents experimental explorations on cooling performance of thermoelectric chillers being driven by solar cells, as well as comparison results to the performance being driven by fixed direct current. Solar energy is clear and limitless and can be collected by solar cells. We use solar cells to drive thermoelectric chillers, where the cold side is connected to the water tank. It is found that 250 mL of water can be cooled from 18.5°C to 13°C, where the corresponding coefficient of performance (COP) is changed between 0.55 and 1.05, when solar insolation is changed between 450 W/m2and 1000 W/m2. The experimental results demonstrate that the thermoelectric chiller driven by solar cell is feasible and effective for energy saving issues.
Preparation of Mesoporous SBA‐16 Silica‐Supported Biscinchona Alkaloid Ligand for the Asymmetric Dihydroxylation of Olefins
Authors: Sarkar Shaheen M. , Ali Md. Eaqub , Rahman Md. Lutfor , Mohd Yusoff Mashitah
Published: June 2014

Optically active cinchona alkaloid was anchored onto mesoporous SBA‐16 silica and the as‐prepared complex was used as a heterogeneous chiral ligand of osmium tetraoxide for the asymmetric dihydroxylation of olefins. The prepared catalytic system provided 90–93% yield of vicinal diol with 92–99% enantioselectivity. The ordered mesoporous SBA‐16 silica was found to be a valuable support for the cinchona alkaloid liganded osmium catalyst system which is frequently used in chemical industries and research laboratories for olefin functionalization.
A Study of Network Violator Interception Based on a Reliable Game Model
Authors: An Shi , Cui Jianxun , Zhao Meng , Wang Jian
Published: June 2014

This study focuses on planning interceptor locations in a general transportation network to maximize the expected benefits from catching violators mixing in public traveler flow. Two reliability‐related characteristics are also integrated into the planning model to make it more practical. One is that each interceptor (e.g., a sensor or a checkpoint) has a failure probability. The second is the existence of a “game” between the interceptor planner and violators. A nonlinear nonconvex binary integer programming model is presented. We develop a simulated annealing (SA) algorithm to solve this model, and numerical experiments are conducted to illustrate the computational efficiency of the proposed algorithm. We also analyze the sensitivity of the disruption probability of interceptors to optimal objective function values and discuss how to determine the values of these parameters in a violator route choice model.
Continuous‐Time Mean‐Variance Asset‐Liability Management with Hidden Markovian Regime Switching
Authors: Zhang Ling
Published: June 2014

This paper considers a continuous‐time mean‐variance asset‐liability management problem with incompletely observable information. An investor can only observe the prices of the asset and liability and the dynamics
of the unobservable states of the underlying financial market is described by a hidden Markovian
chain. The price of the risky asset is assumed to be governed by a hidden Markovian
regime switching geometric Brownian motion and the liability is assumed to follow a hidden
Markovian regime switching Brownian motion with drift, respectively. The appreciation rates of
the risky asset and the liability are modulated by the hidden Markovian chain. By using the
separation principle, the filtering‐estimation problem and the mean‐variance asset‐liability
management problem are discussed. The explicit expressions for the optimal asset‐liability
management strategy and the mean‐variance efficient frontier are determined by using the
stochastic maximum principle.
An Effective Branch and Bound Algorithm for Minimax Linear Fractional Programming
Authors: Jiao Hong-Wei , Wang Feng-Hui , Chen Yong-Qiang
Published: June 2014

An effective branch and bound algorithm is proposed for globally solving minimax linear fractional programming problem (MLFP). In this algorithm, the lower bounds are computed during the branch and bound search by solving a sequence of linear relaxation programming problems (LRP) of the problem (MLFP), which can be derived by using a new linear relaxation bounding technique, and which can be effectively solved by the simplex method. The proposed branch and bound algorithm is convergent to the global optimal solution of the problem (MLFP) through the successive refinement of the feasible region and solutions of a series of the LRP. Numerical results for several test problems are reported to show the feasibility and effectiveness of the proposed algorithm.
Similarity Measure and Entropy of Fuzzy Soft Sets
Authors: Liu Zhicai , Qin Keyun , Pei Zheng
Published: June 2014

Soft set theory, proposed by Molodtsov, has been regarded as an effective mathematical tool to deal with uncertainties. Recently, uncertainty measures of soft sets and fuzzy soft sets have gained attentions from researchers. This paper is devoted to the study of uncertainty measures of fuzzy soft sets. The axioms for similarity measure and entropy are proposed. A new category of similarity measures and entropies is presented based on fuzzy equivalence. Our approach is general in the sense that by using different fuzzy equivalences one gets different similarity measures and entropies. The relationships among these measures and the other proposals in the literatures are analyzed.
Nonlinear Dynamic in an Ecological System with Impulsive Effect and Optimal Foraging
Authors: Zhao Min , Dai Chuanjun
Published: June 2014

The population dynamics of a three-species ecological system with impulsive effect are investigated. Using the theories of impulsive equations and small-amplitude perturbation scales, the conditions for the system to be permanent when the number of predators released is less than some critical value can be obtained. Furthermore, because the predator in the system follows the predictions of optimal foraging theory, it follows that optimal foraging promotes species coexistence. In particular, the less beneficial prey can support the predator alone when the more beneficial prey goes extinct. Moreover, the influences of the impulsive effect and optimal foraging on inherent oscillations are studied using simulation, which reveals rich dynamic behaviors such as period-halving bifurcations, a chaotic band, a periodic window, and chaotic crises. In addition, the largest Lyapunov exponent and the power spectra of the strange attractor, which can help analyze the chaotic dynamic behavior of the model, are investigated. This information will be useful for studying the dynamic complexity of ecosystems.
Noise and Synchronization Analysis of the Cold-Receptor Neuronal Network Model
Authors: Du Ying , Wang Rubin , Qu Jingyi
Published: June 2014

This paper analyzes the dynamics of the cold receptor neural network model. First, it examines noise effects on neuronal stimulus in the model. FromISIplots, it is shown that there are considerable differences between purely deterministic simulations and noisy ones. TheISI-distance is used to measure the noise effects on spike trains quantitatively. It is found that spike trains observed in neural models can be more strongly affected by noise for different temperatures in some aspects; meanwhile, spike train has greater variability with the noise intensity increasing. The synchronization of neuronal network with different connectivity patterns is also studied. It is shown that chaotic and high period patterns are more difficult to get complete synchronization than the situation in single spike and low period patterns. The neuronal network will exhibit various patterns of firing synchronization by varying some key parameters such as the coupling strength. Different types of firing synchronization are diagnosed by a correlation coefficient and theISI-distance method. The simulations show that the synchronization status of neurons is related to the network connectivity patterns.
The Global Existence of Solutions in Time for a Chemotaxis Model with Two Chemicals
Authors: Xu Qian , Liu Xiaolin , Zhang Li
Published: June 2014

This paper concerns the uniform boundedness and global existence of solutions in time for the chemotaxis model with two chemicals. We prove the system has global existence of solutions in time for any dimensionn.