bluuebunny/crossref_metadata_2025 huggingface dataset:
Semagacestat, a γ-secretase inhibitor, activates the growth hormone secretagogue (GHS-R1a) receptor
Authors: Schellekens Harriët , McNamara Orla , Dinan Timothy G , McCarthy Justin V , McGlacken Gerard P , Cryan John F
Published: November 2012

Objectives

Semagacestat, is a γ-secretase inhibitor, which belongs to a class of drugs that are being developed as therapeutic agents for Alzheimer's disease (AD). This study aims to evaluate another potential effect of semagacestat, namely its ability to stimulate the growth hormone secretagogue receptor (GHS-R1a), which may also contribute to its therapeutic efficacy.

Methods

The GHS-R1a-activating potential of semagacestat and its synthetic precursor was assessed in an in vitro calcium mobilization assay in cells expressing the GHS-R1a receptor and compared with that of the endogenous peptide GHS-R1a agonist, acyl-ghrelin, as well as the non-peptidyl synthetic GHS-R1a agonist, MK0677. In addition, semagacestat-mediated cellular trafficking of the GHS-R1a receptor, expressed as an enhanced green fluorescent protein tagged fusion protein, was analysed.

Key findings

Semagacestat and its precursor were shown to activate the GHS-R1a receptor, as demonstrated by an increased GHS-R1a-mediated intracellular calcium influx. Moreover, a synergistic GHS-R1a receptor activation was shown following a combined exposure to ghrelin and semagacestat. In addition, GHS-R1a receptor internalization was observed upon exposure to semagacestat and its precursor.

Conclusion

These data suggest a novel molecular mechanism of action for semagacestat via modest GHS-R1a receptor activation. Studies focusing on the relative functional consequence of such effects in vivo are now warranted.
Physiological and biochemical abilities of robusta coffee leaves for acclimation to cope with temporal changes in light availability
Authors: Rodríguez‐López Nelson F. , Cavatte Paulo C. , Silva Paulo E. M. , Martins Samuel C. V. , Morais Leandro E. , Medina Eduardo F. , DaMatta Fábio M.
Published: November 2012

The effects of varying intensities of light on plants depend on when they occur, even if the total amount of light received is kept constant. We designed an experiment using two clones of robusta coffee (Coffea canephora) intercropped with shelter trees in such a way that allowed us to compare coffee bushes shaded in the morning (SM) with those shaded in the afternoon (SA), and then confronting both with bushes receiving full sunlight over the course of the day (FS). The SM bushes displayed better gas‐exchange performance than their SA and FS counterparts, in which the capacity for CO2 fixation was mainly constrained by stomatal (SA bushes) and biochemical (FS bushes) factors. Physiological traits associated with light capture were more responsive to temporal fluctuations of light rather than to the amount of light received, although this behavior could be a clone‐specific response. The activity of key antioxidant enzymes differed minimally when comparing the SM and SA clones, but was much larger in FS clones. No signs of photoinhibition or cell damage were found regardless of the light treatments. Acclimations to varying light supplies had no apparent additional cost for constructing and maintaining the leaves regardless of the light supply. Both the SM and SA individuals displayed higher return in terms of revenue streams (e.g. higher mass‐based light‐saturated photosynthetic rates, photosynthetic nitrogen use efficiencies and long‐term water use efficiencies) than their FS counterparts. In conclusion, shading may improve the physiological performance of coffee bushes growing in harsh, tropical environments.
Hypergravity and Multiple Reflections in Wave Propagation in the Aorta
Authors: Kroot J. M. B. , Giannopapa C. G.
Published: November 2012

Hypergravity and gravity changes encountered in, e.g., airplanes, rollercoasters, and spaceflight can result in headaches or loss of consciousness due to decreased cerebral blood flow. This paper describes the effect of hypergravity and gravity changes on the pressure in the aorta and the distension of its wall. The model presented consists of a pressure part caused by gravity and a part representing pressure waves propagating through the vessel. The total pressure is described by a one-dimensional formulation in the frequency domain. To accommodate for geometrical and material variations, the vessel is modeled as a series of sections in which multiple reflections can occur. Results are presented for constant and varying gravity in straight and tapered flexible vessels.
Structural-Acoustic Vibration Problems in the Presence of Strong Coupling
Authors: Voss Heinrich , Stammberger Markus
Published: November 2012

Free vibrations of fluid–solid structures are governed by unsymmetric eigenvalue problems. A common approach which works fine for weakly coupled systems is to project the problem to a space spanned by modes of the uncoupled system. For strongly coupled systems, however, the approximation properties are not satisfactory. This paper reports on a framework for taking advantage of the structure of the unsymmetric eigenvalue problem allowing for a variational characterization of its eigenvalues and structure preserving iterative projection methods. We further cover an adjusted automated multilevel substructuring (AMLS) method for huge fluid–solid structures. The reliability and efficiency of the method are demonstrated by the free vibrations of a structure completely filled with water.
Drag Coefficient and Two-Phase Friction Multiplier on Tube Bundles Subjected to Two-Phase Cross-Flow
Authors: Sim W. G. , Mureithi Njuki W.
Published: November 2012

An approximate analytical model, to predict the drag coefficient on a cylinder and the two-phase Euler number for upward two-phase cross-flow through horizontal bundles, has been developed. To verify the model, two sets of experiments were performed with an air–water mixture for a range of pitch mass fluxes and void fractions. The experiments were undertaken using a rotated triangular (RT) array of cylinders having a pitch-to-diameter ratio of 1.5 and cylinder diameter 38 mm. The void fraction model proposed by Feenstra et al. was used to estimate the void fraction of the flow within the tube bundle. An important variable for drag coefficient estimation is the two-phase friction multiplier. A new drag coefficient model has been developed, based on the single-phase flow Euler number formulation proposed by Zukauskas et al. and the two-phase friction multiplier in duct flow formulated by various researchers. The present model is developed considering the Euler number formulation by Zukauskas et al. as well as existing two-phase friction multiplier models. It is found that Marchaterre's model for two-phase friction multiplier is applicable to air–water mixtures. The analytical results agree reasonably well with experimental drag coefficients and Euler numbers in air–water mixtures for a sufficiently wide range of pitch mass fluxes and qualities. This model will allow researchers to provide analytical estimates of the drag coefficient, which is related to two-phase damping.
Optimization of Waterflooding Performance in a Layered Reservoir Using a Combination of Capacitance-Resistive Model and Genetic Algorithm Method
Authors: Mamghaderi Azadeh , Bastami Alireza , Pourafshary Peyman
Published: November 2012

Managing oil production from reservoirs to maximize the future economic return of the asset is an important issue in petroleum engineering. In many applications in reservoir modeling and management, there is a need for rapid estimation of large-scale reservoirs. The capacitance-resistive model (CRM), regarded as a promising rapid evaluator of reservoir performance, has recently been used for simulation of single-layer reservoirs. Injection and production rates are considered as input and output signals in this model. Connections between the wells and the effects of injection rates on production rates are calculated based on these signals to develop a simple model for the reservoir. In this study, CRM is improved to model a multilayer reservoir and is applied to estimate and optimize waterflooding performance in an Iranian layered reservoir. In this regard, CRM is coupled with production logging tools (PLT) data to study the effects of layers. A fractional-flow model is also coupled with the developed CRM to estimate oil production. Genetic algorithm (GA) method is used to minimize the error objective function for the total production history and oil production history to evaluate model parameters. GA is then used to maximize oil production by reallocating the injected water volumes, which is the main purpose of this research. The results show that our fast method is able to model liquid and oil production history and is in good agreement with available field data. Taking into account the reservoir constraints, the optimal injection schemes have been obtained. For the proposed injection profile, the field hydrocarbon production will increase by up to 1.8% until 2016. Also, the wells will reach the water-cut constraint 2 yr later than the current situation, which increases the production period of the field.
Adaptive Sliding Mode Control for Synchronization of a Fractional-Order Chaotic System
Authors: Li Chunlai , Su Kalin , Wu Lei
Published: November 2012

This paper proposes a three-dimensional autonomous chaotic system which displays some interest dynamical behaviors such as invariable Lyapunov exponent spectrums and controllable signal amplitude. The corresponding fractional version of the proposed system is obtained. A single state controller for synchronization of this fractional-order chaotic system is developed based on the techniques of sliding mode control and adaptive control. Numerical simulations are provided to demonstrate the feasibility of the presented synchronization method.
Development of Methods to Fully Saturate Carbon Foam With Paraffin Wax Phase Change Material for Energy Storage
Authors: Warzoha Ron , Sanusi Omar , McManus Brian , Fleischer Amy S.
Published: November 2012

In this work, the effect of infiltration method on the saturation rate of paraffin phase change material within graphite foams is experimentally investigated. Graphite foams infiltrated with paraffin have been found to be effective for solar energy storage, but it has been found that it is difficult to completely saturate the foam with paraffin. The effectiveness of the fill will have a significant effect on the performance of the system, but the data on fill ratio are difficult to separate from confounding effects such as type of graphite or phase change material (PCM) used. This will be the first detailed quantitative study that directly isolates the effect of infiltration method on fill ratio of PCM in graphite foams. In this work, the two most commonly reported methods of infiltration are studied under controlled conditions. In fact, the effect of the infiltration method on the paraffin saturation rate is found to be highly significant. It was found that the more commonly used simple submersion technique is ineffective at filling the voids within the graphite foam. Repeated tests showed that at least 25% of the reported open space within the foam was left unfilled. In contrast, it was found that the use of a vacuum oven lead to a complete fill of the foam. These high saturation rates were achieved with significantly shorter dwell times than in previously reported studies and can be of significant use to others working in this area.
Optimization of a Y-Graft Design for Improved Hepatic Flow Distribution in the Fontan Circulation
Authors: Yang Weiguang , Feinstein Jeffrey A. , Shadden Shawn C. , Vignon-Clementel Irene E. , Marsden Alison L.
Published: November 2012

Single ventricle heart defects are among the most serious congenital heart diseases, and are uniformly fatal if left untreated. Typically, a three-staged surgical course, consisting of the Norwood, Glenn, and Fontan surgeries is performed, after which the superior vena cava (SVC) and inferior vena cava (IVC) are directly connected to the pulmonary arteries (PA). In an attempt to improve hemodynamic performance and hepatic flow distribution (HFD) of Fontan patients, a novel Y-shaped graft has recently been proposed to replace the traditional tube-shaped extracardiac grafts. Previous studies have demonstrated that the Y-graft is a promising design with the potential to reduce energy loss and improve HFD. However these studies also found suboptimal Y-graft performance in some patient models. The goal of this work is to determine whether performance can be improved in these models through further design optimization. Geometric and hemodynamic factors that influence the HFD have not been sufficiently investigated in previous work, particularly for the Y-graft. In this work, we couple Lagrangian particle tracking to an optimal design framework to study the effects of boundary conditions and geometry on HFD. Specifically, we investigate the potential of using a Y-graft design with unequal branch diameters to improve hepatic distribution under a highly uneven RPA/LPA flow split. As expected, the resulting optimal Y-graft geometry largely depends on the pulmonary flow split for a particular patient. The unequal branch design is demonstrated to be unnecessary under most conditions, as it is possible to achieve the same or better performance with equal-sized branches. Two patient-specific examples show that optimization-derived Y-grafts effectively improve the HFD, compared to initial nonoptimized designs using equal branch diameters. An instance of constrained optimization shows that energy efficiency slightly increases with increasing branch size for the Y-graft, but that a smaller branch size is preferred when a proximal anastomosis is needed to achieve optimal HFD.
Mechanical Compromise of Partially Lacerated Flexor Tendons
Authors: Kondratko Jaclyn , Duenwald-Kuehl Sarah , Lakes Roderic , Vanderby Ray
Published: November 2012

Tendons function to transmit loads from muscle to move and stabilize joints and absorb impacts. Functionality of lacerated tendons is diminished, however clinical practice often considers surgical repair only after 50% or more of the tendon is lacerated, the “50% rule.” Few studies provide mechanical insight into the 50% rule. In this study cyclic and static stress relaxation tests were performed on porcine flexor tendons before and after a 0.5, 1.0, 2.0, or 2.75 mm deep transverse, midsubstance laceration. Elastic and viscoelastic properties, such as maximum stress, change in stress throughout each test, and stiffness, were measured and compared pre- and post-laceration. Nominal stress and stiffness parameters decreased, albeit disproportionately in magnitude, with increasing percent loss of cross-sectional area. Conversely, mean stress at the residual area (determined using remaining intact area at the laceration cross section) exhibited a marked increase in stress concentration beginning at 47.2% laceration using both specified load and constant strain analyses. The marked increase in stress concentration beginning near 50% laceration provides mechanical insight into the 50% rule. Additionally, a drastic decrease in viscoelastic stress parameters after only an 8.2% laceration suggests that time-dependent mechanisms protecting tissues during impact loadings are highly compromised regardless of laceration size.
The Buckling and Postbuckling of Fibrils Adhering to a Rigid Surface
Authors: Stark Sebastian , Begley Matthew R. , McMeeking Robert M.
Published: November 2012

Recent experiments in which arrays of compliant fibrils are compressed axially against a rigid surface and then released have shown that there is load-displacement hysteresis during this process, accompanied by buckling and unbuckling of the fibrils. Furthermore, the adhesive performance of the system is decreased by such prior buckling. We present a model describing the buckling and postbuckling characteristics of a fibril with an aspect ratio of 10 or greater. The possibility during buckling of partial detachment of the end of the fibril is taken into account. The results are presented and discussed for both load and displacement control and the load-displacement hysteresis is identified. It is found that due to instabilities sudden spreading and shrinkage of the adhered area at the end of the fibril can accompany the hysteresis. Numerical results are provided to substantiate the findings and possible reasons for the observed influence of buckling on adhesive performance are reviewed.
Design and fabrication of a metallic nanostamp using UV nanoimprinting and electroforming for replicating discrete track media with feature size of 35 nm
Authors: Lim Jiseok , Hong Hyun-guk , Han Jungjin , Cho Eikhyun , Kim Young-joo , Hatano Hiroshi , Arai Norikazu
Published: November 2012

The demand for high-density data-storage media is increasing, necessitating the development of novel magnetic data-storage technologies. Among the various types of storage media, discrete track media (DTM) is an emerging technology that is being used to overcome the limitations of conventional continuous magnetic data-storage technology, such as the superparamagnetic effect and medium noise. In this study, the authors propose a method of fabricating a metallic stamp for replicating DTM patterns using ultraviolet (UV) nanoimprinting and electroforming, which are inexpensive processes that can be used to fabricate nanostructures with high precision. First, a silicon nanomaster with a feature size of 35 nm and a pitch of 70 nm was designed and fabricated by electron-beam recording and inductively coupled plasma etching. The measured pitch of the silicon master was 71.6 nm. Then, a polymeric master with a full track of nanoline patterns was then replicated from the silicon nanomaster via UV nanoimprinting. To improve the releasing properties during UV nanoimprinting, the silicon nanomaster was coated with a self-assembled monolayer of fluoroctatrichlorosilane. The measured average pitch and height of the replicated polymer master were 71.5 and 61 nm, respectively. Then, a metallic nanostamp with a thickness of 300 μm and a diameter of 80 mm was fabricated using electroforming. The metallic nanostamp was successfully fabricated, and its geometrical properties were measured and analyzed. The pitch and height of fabricated nickel stamp were 71.2 and 60.3 nm, respectively.
Comparative assessment of segmentation algorithms for tumor delineation on a test‐retest [11C]choline dataset
Authors: Tomasi Giampaolo , Shepherd Tony , Turkheimer Federico , Visvikis Dimitris , Aboagye Eric
Published: November 2012

Purpose:

Many methods have been proposed for tumor segmentation from positron emission tomography images. Because of the increasingly important role that [11C]choline is playing in oncology and because no study has compared segmentation methods on this tracer, the authors assessed several segmentation algorithms on a [11C]choline test‐retest dataset.

Methods:

Fixed and adaptive threshold‐based methods, fuzzy C‐means (FCM), Cannyˈs edge detection method, the watershed transform, and the fuzzy locally adaptive Bayesian algorithm (FLAB) were used. Test‐retest [11C]choline scans of nine patients with breast cancer were considered and the percent test‐retest variability %VARTEST‐RETEST of tumor volume (TV) was employed to assess the results. The same methods were then applied to two denoised datasets generated by applying either a Gaussian filter or the wavelet transform.

Results:

The (semi)automated methods FCM, FLAB, and Canny emerged as the best ones in terms of TV reproducibility. For these methods, the %root mean square error %RMSE of %VARTEST‐RETEST, defined as , was in the range 10%–21.2%, depending on the dataset and algorithm. Threshold‐based methods gave TV estimates which were extremely variable, particularly on the unsmoothed data; their performance improved on the denoised datasets, whereas smoothing did not have a remarkable impact on the (semi)automated methods. TV variability was comparable to that of SUVMAX and SUVMEAN (range 14.7%–21.9% for %RMSE of %VARTEST‐RETEST, after the exclusion of one outlier, 40%–43% when the outlier was included).

Conclusions:

The TV variability obtained with the best methods was similar to the one reported for TV in previous [18F]FDG and [18F]FLT studies and to the one of SUVMAX/SUVMEAN on the authors’ [11C]choline dataset. The good reproducibility of [11C]choline TV warrants further studies to test whether TV could predict early response to treatment and survival, as for [18F]FDG, to complement/substitute the use of SUVMAX and SUVMEAN.
Measurement of blood flow and xenon solubility coefficient in the human liver by xenon‐enhanced computed tomography
Authors: Sase Shigeru , Takahashi Hideaki , Shigefuku Ryuta , Ikeda Hiroki , Kobayashi Minoru , Matsumoto Nobuyuki , Suzuki Michihiro
Published: November 2012

Purpose:

The goal of this work was to develop a method of calculating blood flow and xenon solubility coefficient (λ) in the hepatic tissue by xenon‐enhanced computed tomography (Xe‐CT) and to demonstrate λ can be used as a measure of fat content in the human liver.

Methods:

A new blood supply model is introduced which incorporates both arterial blood and portal venous blood which join and together flow into hepatic tissue. We applied Fickˈs law to the model. It was theoretically derived that the time course of xenon concentration in the inflow blood (the mixture of the arterial blood and the portal venous blood) can be approximated by a monoexponential function. This approximation made it possible to obtain the time‐course change rate (KI) of xenon concentration in the inflow blood using the time course of xenon concentration in the hepatic tissue by applying the algorithm we had reported previously. KI was used to calculate blood flow and λ for each pixel in the CT image of the liver. Twenty‐six patients (49.2 ± 18.3 years) with nonalcoholic steatohepatitis underwent Xe‐CT abdominal studies and liver biopsies. Steatosis of the liver was evaluated using the biopsy specimen and its severity was divided into ten grades according to the fat deposition percentage [(severity 1) ⩽ 10%, 10 % <(severity 2) ⩽ 20%, …, 90% < (severity 10) ⩽ 100%]. For each patient, blood flow and λ maps of the liver were created, and the average λ value () was compared with steatosis severity and with the CT value ratio of the liver to the spleen (liver/spleen ratio).

Results:

There were good correlations between and steatosis severity (r = 0.914, P < 0.0001), and between and liver/spleen ratio (r = −0.881, P < 0.0001). Ostwald solubility for xenon in the hepatic tissue (tissue Xe solubility), which is calculated using and the hematocrit value of the patient, also showed a good correlation with steatosis severity (r = 0.910, P < 0.0001). ranged from 0.86 to 7.81, and tissue Xe solubility ranged from 0.12 to 1.16. This range of solubility is reasonable considering the reported Ostwald solubility coefficients for xenon in the normal liver and in the fat tissue are 0.10 and 1.3, respectively, at 37 °C. The average blood flow value ranged from 15.3 to 53.5 ml/100 ml tissue/min.

Conclusions:

A method of calculating blood flow andλ in the hepatic tissue was developed by means of Xe‐CT. This method would be valid even if portosystemic shunts exist; it is shown that λ maps can be used to deduce fat content in the liver. As a noninvasive modality, Xe‐CT would be applicable to the quantitative study of fatty change in the human liver.
Time to Integrate Clinical and Research Informatics
Authors: Katzan Irene L. , Rudick Richard A.
Published: November 2012

Integration of electronic clinical and research data can streamline clinical research, patient care, and building of a learning health care system.
The Clearly Misunderstood Case of ApoB-100
Authors: Oviedo-Orta Ernesto
Published: November 2012

Apolipoprotein B-100 and low-density lipoprotein bind to bacterial lipoteichoic acid and interfere with the antibacterial immune response.
Ear Power: Batteries Now Included
Authors: Shrout Joshua D.
Published: November 2012

The inner ear displays an electrochemical gradient that can be used to power small electronic devices.
Dissecting the Mystery Around Multiple Sclerosis
Authors: Skarke Carsten
Published: November 2012

In an animal counterpart of multiple sclerosis, prostacyclin—a lipid eicosanoid—promotes neuronal remodeling and recovery.
Draft Genome Sequence of Wickerhamomyces ciferrii NRRL Y-1031 F-60-10
Authors: Schneider Jessica , Andrea Heiko , Blom Jochen , Jaenicke Sebastian , Rückert Christian , Schorsch Christoph , Szczepanowski Rafael , Farwick Mike , Goesmann Alexander , Pühler Alfred , Schaffer Steffen , Tauch Andreas , Köhler Tim , Brinkrolf Karina
Published: November 2012

Wickerhamomyces ciferrii
is a microorganism characterized by the production and secretion of large amounts of acetylated sphingoid bases, in particular tetraacetyl phytosphingosine. Here, we present the 15.90-Mbp draft genome sequence of
W. ciferrii
NRRL Y-1031 F-60-10 generated by pyrosequencing and
de novo
assembly. The draft genome sequence comprising 364 contigs in 150 scaffolds was annotated and covered 6,702 protein-coding sequences. This information will contribute to the metabolic engineering of this yeast to improve the yield and spectrum of acetylated sphingoid bases in biotechnological production.
Genome Sequence of the Trichosporon asahii Environmental Strain CBS 8904
Authors: Yang Rong Ya , Li Hai Tao , Zhu He , Zhou Guang Peng , Wang Meng , Wang Lei
Published: November 2012

This is the first report of the genome sequence of
Trichosporon asahii
environmental strain CBS 8904, which was isolated from maize cobs. Comparison of the genome sequence with that of clinical strain CBS 2479 revealed that they have >99% chromosomal and mitochondrial sequence identity, yet CBS 8904 has 368 specific genes. Analysis of clusters of orthologous groups predicted that 3,307 genes belong to 23 functional categories and 703 genes were predicted to have a general function.
Antagonistic Rgg Regulators Mediate Quorum Sensing via Competitive DNA Binding in Streptococcus pyogenes
Authors: LaSarre Breah , Aggarwal Chaitanya , Federle Michael J.
Published: November 2012

Recent studies have established the fact that multiple members of the Rgg family of transcriptional regulators serve as key components of quorum sensing (QS) pathways that utilize peptides as intercellular signaling molecules. We previously described a novel QS system in
Streptococcus pyogenes
which utilizes two Rgg-family regulators (Rgg2 and Rgg3) that respond to neighboring signaling peptides (SHP2 and SHP3) to control gene expression and biofilm formation. We have shown that Rgg2 is a transcriptional activator of target genes, whereas Rgg3 represses expression of these genes, and that SHPs function to activate the QS system. The mechanisms by which Rgg proteins regulate both QS-dependent and QS-independent processes remain poorly defined; thus, we sought to further elucidate how Rgg2 and Rgg3 mediate gene regulation. Here we provide evidence that
S. pyogenes
employs a unique mechanism of direct competition between the antagonistic, peptide-responsive proteins Rgg2 and Rgg3 for binding at target promoters. The highly conserved, shared binding sites for Rgg2 and Rgg3 are located proximal to the −35 nucleotide in the target promoters, and the direct competition between the two regulators results in concentration-dependent, exclusive occupation of the target promoters that can be skewed in favor of Rgg2
in vitro
by the presence of SHP. These results suggest that exclusionary binding of target promoters by Rgg3 may prevent Rgg2 binding under SHP-limiting conditions, thereby preventing premature induction of the quorum sensing circuit.

IMPORTANCE
Rgg-family transcriptional regulators are widespread among low-G+C Gram-positive bacteria and in many cases contribute to bacterial physiology and virulence. Only recently was it discovered that several Rgg proteins function in cell-to-cell communication (quorum sensing [QS]) via direct interaction with signaling peptides. The mechanism(s) by which Rgg proteins mediate regulation is poorly understood, and further insight into Rgg function is anticipated to be of great importance for the understanding of both regulatory-network architecture and intercellular communication in Rgg-containing species. The results of this study on the Rgg2/3 QS circuit of
S. pyogenes
demonstrate that DNA binding of target promoters by the activator Rgg2 is directly inhibited by competitive binding by the repressor Rgg3, thereby preventing transcriptional activation of the target genes and premature induction of the QS circuit. This is a unique regulatory mechanism among Rgg proteins and other peptide-responsive QS regulators.
Contact allergic gastritis: an underdiagnosed entity?
Authors: Pföhler Claudia , Körner Rebecca , Vogt Thomas , Müller Cornelia S L
Published: November 2012

Only a few cases of contact allergic gastritis in patients with nickel allergy have been reported. We report a case of probable contact-allergic gastritis in a 46-year-old woman. Clinical examination revealed lichenoid mucosal lesions of the gums adjacent to bridges and crowns that had been implanted several weeks back. Since implantation, the patient had suffered from gastrointestinal complaints (including stomach pain). Gastroscopy showed eosinophilic gastritis. Patch testing done under the diagnosis of contact allergic stomatitis showed positive reactions to: gold sodium thiosulphate; manganese (II) chloride; nickel (II) sulphate; palladium chloride; vanadium (III) chloride and zirconium (IV) chloride. The crowns and bridge contained gold, palladium and zirconium chloride, hence they were replaced by titan-based dentition. Shortly after replacing the artificial dentition, all gastrointestinal symptoms resolved spontaneously without further treatment. Delayed-type allergy against the components of artificial dentition seemed to be the cause of gastritis.
Disturbance of consciousness and involuntary movements caused by pregabalin
Authors: Shimizu Taro , Yoshida Tsuneyasu , Kitamura Koichi , Hamada Osamu
Published: November 2012

A 91-year-old man with chronic low-back pain presented with 1-day history of disturbance of consciousness and myoclonus of all of his extremities and face. Laboratory examinations revealed no abnormalities. Administration of benzodiazepine for the myoclonus resulted in immediate and complete disappearance of the symptoms. He recently started taking pregabalin (Lyrica capsules) which was prescribed for low-back pain 3 days ago. The day following admission, he discontinued pregabalin. He did not experience recurrence of his symptoms any more. We concluded that the neurological symptoms he experienced were possibly due to pregabalin.
Health-related quality of life after serious occupational injury in Egyptian workers: a cross-sectional study
Authors: Salah Eldin Waleed , Hirshon Jon Mark , Smith Gordon S , Kamal Abdel-Aziz Mohamad , Abou-El-Fetouh Aisha , El-Setouhy Maged
Published: November 2012

Objectives

Occupational injuries can have severe socioeconomic consequences; however, little research has examined the health-related quality of life (HRQoL) of workers following occupational injuries, especially in developing countries. This study was to employ the European Quality of Life Five Dimensions (EQ-5D) tool to measure HRQoL 6 months following serious occupational injury sustained by insured workers in the East Delta Region of Egypt.

Design

This cross-sectional study was conducted from July to December 2008 among workers injured severely enough to be off work for at least 6 months after an occupational injury.

Setting

The Nile Insurance Hospital in Qalyubia, Egypt.

Participants

Adult workers returning for follow-up evaluation after being given 6 months off work by a physician for an occupational injury.

Outcomes

The workers described their health and quality of life using the EQ-5D instrument.

Results

Most study participants were male (n=118 (90%)), with mean age of 41.5 years. Fractures were the most common type of injury (n=96 (73%)), mostly involving the lower limbs (n=70 (53%)). Participants identified persistent problems related to mobility (n=78 (60%)), self-care (n=69 (53%)), performing usual activities (n=109 (83%)), pain/discomfort (n=119 (91%)) and anxiety/depression (n=51 (40%)). The perceived HRQoL estimated by the mean (±SD) visual analogue scale (VAS) score among injured workers was 61.6±17.9. Multivariate linear regression showed an association between poor VAS score and amputations, mobility limitation, self-care problems, pain/discomfort and anxiety/depression.

Conclusions

Some people with occupational injuries experience significant problems such as pain/discomfort, functional limitations and anxiety/depression, long after the injury. Improvement in pain management strategies and physical and psychological rehabilitation may improve their health-related quality of life.
CoMPASs: IOn programme (Care Of Memory Problems in Advanced Stages of dementia: Improving Our Knowledge): protocol for a mixed methods study
Authors: Jones Louise , Harrington Jane , Scott Sharon , Davis Sarah , Lord Kathryn , Vickerstaff Victoria , Round Jeff , Candy Bridget , Sampson Elizabeth L
Published: November 2012

Introduction

Approximately 700 000 people in the UK have dementia, rising to 1.2 million by 2050; one-third of people aged over 65 will die with dementia. Good end-of-life care is often neglected, and detailed UK-based research on symptom burden and needs is lacking. Our project examines these issues from multiple perspectives using a rigorous and innovative design, collecting data which will inform the development of pragmatic interventions to improve care.

Methods and analysis

To define in detail symptom burden, service provision and factors affecting care pathways we shall use mixed methods: prospective cohort studies of people with advanced dementia and their carers; workshops and interactive interviews with health professionals and carers, and a workshop with people with early stage dementia. Interim analyses of cohort data will inform new scenarios for workshops and interviews. Final analysis will include cohort demographics, the symptom burden and health service use over the follow-up period. We shall explore the level and nature of unmet needs, describing how comfort and quality of life change over time and differences between those living in care homes and those remaining in their own homes. Data from workshops and interviews will be analysed for thematic content assisted by textual grouping software. Findings will inform the development of a complex intervention in the next phase of the research programme.

Ethics and dissemination

Ethical approval was granted by National Health Service ethical committees for studies involving people with dementia and carers (REC refs. 12/EE/0003; 12/LO/0346), and by university ethics committee for work with healthcare professionals (REC ref. 3578/001). We shall present our findings at conferences, and in peer-reviewed journals, prepare detailed reports for organisations involved with end-of-life care and dementia, publicising results on the Marie Curie website. A summary of the research will be provided to participants if requested.
Occlusion of a clival dural arteriovenous fistula using a novel approach through the foramen ovale
Authors: Urdaneta-Moncada Alfonso , Feng Lei , Chen Joseph
Published: November 2012

Dural arteriovenous fistulas (DAVFs) are abnormal connections between arteries and veins that are classified by location, morphology or direction of venous drainage. Treatment of DAVFs is undertaken in patients with severe symptoms or those with retrograde cortical venous drainage and/or venous ectasia. Much is written regarding the treatment of DAVFs involving the transverse sigmoid sinuses, cavernous sinus and tentorium, but little is written concerning the treatment of clival DAVFs. We demonstrate a novel transforaminal percutaneous approach through the foramen ovale as a viable method to occlude a clival vein. Specialised software was used to create a safe trajectory to the DAVF via the foramen ovale. The patient then underwent successful occlusion of the clival DAVF, thus further increasing the neurointerventionalist's armamentarium when attempting to treat difficult to reach clival DAVFs.
Treatment of a pediatric recurrent fusiform middle cerebral artery (MCA) aneurysm with a flow diverter
Authors: Burrows Anthony M , Zipfel Gregory , Lanzino Giuseppe
Published: November 2012

Pediatric patients with aneurysm often have different localizations and morphologies from adults and recurrences are not uncommon after successful clip reconstruction/obliteration. Treatment of a recurrent pediatric aneurysm after clip ligation is a technical challenge. We present the case of an adolescent with a middle cerebral artery (MCA) fusiform aneurysm which recurred following clip reconstruction and bypass. The aneurysm was successfully treated with endovascular flow diversion.
Cerebral hyperperfusion after flow diversion of large intracranial aneurysms
Authors: Chiu Albert Ho Yuen , Wenderoth Jason
Published: November 2012

Cerebral hyperperfusion syndrome has been proposed to be caused by rapidly increased blood flow into chronically hypoperfused parenchyma with resultant impaired autoregulation, and has been noted after clipping of intracranial aneurysms and carotid stenting. The occurrence of the syndrome after endovascular flow diversion, however, has not been previously described. A 52-year-old woman was admitted electively for flow diverter treatment of a recurrent ventral paraclinoid aneurysm arising within a dysplastic segment of the left internal carotid artery. During the immediate postprocedural period the patient was found to have confusion, right hemiparesis, facial droop and dysarthria, which resolved with blood pressure control. Subsequent CT perfusion on day 11 demonstrated mildly elevated cerebral blood flow, cerebral blood volume and permeability values in the left hemisphere.
Mechanism of cardiomyocyte PGC-1α gene regulation by ERRα
Authors: Ramjiawan Angela , Bagchi Rushita A. , Albak Laura , Czubryt Michael P.
Published: November 2012

Peroxisome proliferator-activated receptor (PPAR) γ coactivator 1α (PGC-1α) regulates critical genes involved in cardiac mitochondrial biogenesis and fatty acid oxidation, and its loss is associated with impaired metabolism and various cardiac pathologies. Estrogen-related receptor α (ERRα) targets many of the same genes as PGC-1α, and extensive cross talk exists between these 2 regulators. Here we report the identification of an evolutionarily conserved ERRα binding site within the PGC-1α promoter. Using luciferase reporter assays and overexpression, inhibition, or knockdown of ERRα, we show that PGC-1α expression is critically dependent upon ERRα in primary cardiomyocytes. We demonstrate that short-term hypoxia results in reduced ERRα mRNA expression, which precedes a similar loss of PGC-1α mRNA. However, chromatin immunoprecipitation reveals that despite a key role for ERRα in regulating PGC-1α in normoxic cardiomyocytes, ERRα loss is not responsible for PGC-1α loss in hypoxia. Histone deacetylase 5 (HDAC5) has previously been demonstrated to strongly inhibit expression of PGC-1α, and we show that overexpression of ERRα is sufficient to overcome this repressive effect. Our data elucidates the mechanism by which ERRα regulates cardiac PGC-1α gene expression, and suggests that ERRα may provide a means to normalize PGC-1α expression that could be useful in the development of strategies aimed at improving cardiac metabolism in disease.
Identification of amino acids responsible for stop codon recognition for polypeptide chain release factor
Authors: Xu Lijun , Hao Yanrong , Li Cui , Shen Quan , Chai Baofeng , Wang Wei , Liang Aihua
Published: November 2012

One factor involved in eukaryotic translation termination is class 1 release factor in eukaryotes (eRF1), which functions to decode stop codons. Variant code species, such as ciliates, frequently exhibit altered stop codon recognition. Studies revealed that some class-specific residues in the eRF1 N-terminal domain are responsible for stop codon reassignment in ciliates. Here, we investigated the effects on stop codon recognition of chimeric eRF1s containing the N-terminal domain of Euplotes octocarinatus and Blepharisma japonicum eRF1 fused to Saccharomyces cerevisiae M and C domains using dual luciferase read-through assays. Mutation of class-specific residues in different eRF1 classes was also studied to identify key residues and motifs involved in stop codon decoding. As expected, our results demonstrate that 3 pockets within the eRF1 N-terminal domain were involved in decoding stop codon nucleotides. However, allocation of residues to each pocket was revalued. Our data suggest that hydrophobic and class-specific surface residues participate in different functions: modulation of pocket conformation and interaction with stop codon nucleotides, respectively. Residues conserved across all eRF1s determine the relative orientation of the 3 pockets according to stop codon nucleotides. However, quantitative analysis of variant ciliate and yeast eRF1 point mutants did not reveal any correlation between evolutionary conservation of class-specific residues and termination-related functional specificity and was limited in elucidating a detailed mechanism for ciliate stop codon reassignment. Thus, based on isolation of suppressor tRNAs from Euplotes and Tetrahymena, we propose that stop codon reassignment in ciliates may be controlled by cooperation between eRF1 and suppressor tRNAs.
Modified Ricci flow and asymptotically nonflat spaces
Authors: Chatterjee Shubhayu , Banerjee Narayan
Published: November 2012

The present work extends the application of a modified Ricci flow equation to an asymptotically nonflat space, namely, Marder's cylindrially symmetric space. It is found that the flow equation has a solution at least in a particular case.
KNOTTED STRINGS AND LEPTONIC FLAVOR STRUCTURE
Authors: KEPHART T. W. , LESER P. , PÄS H.
Published: November 2012

We propose a third idea for the explanation of the leptonic flavor structure in addition to the prominent approaches based on flavor symmetry and anarchy. Typical flavor patterns can be modeled by using mass spectra obtained from the discrete lengths spectrum of tight knots and links. We assume that a string theory model exists in which this idea can be incorporated via the Majorana mass structure of a type I seesaw model. It is shown by a scan over the parameter space that such a model is able to provide an excellent fit to current neutrino data and that it predicts a normal neutrino mass hierarchy as well as a small mixing angle θ13. Startlingly, such scenarios could be related to the dimensionality of spacetime via an anthropic argument.
AN EFFECTIVE THEORY OF ACCELERATED EXPANSION
Authors: JIMENEZ RAUL , TALAVERA P. , VERDE LICIA
Published: November 2012

We work out an effective theory of accelerated expansion for the background to describe general phenomena of inflation and acceleration (dark energy) in the universe. Our aim is to determine from theoretical grounds, in a physically motivated and model-independent way, which and how many (free) parameters are needed to broadly capture the physics of a theory describing the background of cosmic acceleration. Our goal is to make as much transparent as possible the physical interpretation of the parameters describing the expansion. We show that, at leading order, there are five independent parameters, of which one can be constrained via general relativity tests. The other four parameters need to be determined by observing and measuring the cosmic expansion rate only, H(z). Therefore, we suggest that future cosmology surveys focus on obtaining an accurate value as possible measurement of H(z) to constrain the nature of accelerated expansion.
MULTI-SCALE GRADIENT INVARIANT FOR FACE RECOGNITION UNDER VARYING ILLUMINATION
Authors: XU BIN , TANG YUAN YAN , FANG BIN , SHANG ZHAO WEI
Published: November 2012

In this paper, a novel approach derived from image gradient domain called multi-scale gradient faces (MGF) is proposed to abstract multi-scale illumination-insensitive measure for face recognition. MGF applies multi-scale analysis on image gradient information, which can discover underlying inherent structure in images and keep the details at most while removing varying lighting. The proposed approach provides state-of-the-art performance on Extended YaleB and PIE: Recognition rates of 99.11% achieved on PIE database and 99.38% achieved on YaleB which outperforms most existing approaches. Furthermore, the experimental results on noised Yale-B validate that MGF is more robust to image noise.
CONTEXT AWARE INFORMATION DELIVERY FOR MOBILE DEVICES
Authors: GUO JINHONG K. , KNOTT STEPHEN A. , SHEU RAY YUAN , HOFMANN MARTIN O.
Published: November 2012

Delivering the right amount of information to the right person is vital on the tactical battlefield. With the increasing use of mobile devices by the military, delivering relevant information instantaneously to the warfighter becomes possible. However, large quantities of data are being generated constantly while the human processing power and communication channels are limited. Therefore, data must be processed so it can be evaluated against operational needs. This data is collected in multiple modalities include images, videos and field reports with multi-sensor data. Providing automated processing of unstructured information promises to effectively connect information processing with operational decision making, dramatically reducing the time needed to identify relevant information for mission planning and execution. We describe a multi-view learning technique that augments the feature set used by a classifier in one modality with entity relationships discovered in other modalities. To accommodate the limited computation power of field devices, mostly handhelds, the multi-view learning algorithm is low complexity. It applies to multiple modalities, leveraging many-to-many correspondences among different modalities. Experiments on image and text are presented in the paper which show more than 20% improvement over categorizing text or images independently. The categorized information is matched to the mission and task needs. Finally, relevant information needs to be transmitted via limited bandwidth negotiated from limited resources.
SPEED-INDEPENDENT GAIT IDENTIFICATION FOR MOBILE DEVICES
Authors: DEL POZO GONZALO BAILADOR , SÁNCHEZ-ÁVILA CARMEN , DE-SANTOS-SIERRA ALBERTO , GUERRA-CASANOVA JAVIER
Published: November 2012

Due to the intensive use of mobile phones for different purposes, these devices usually contain confidential information which must not be accessed by another person apart from the owner of the device. Furthermore, the new generation phones commonly incorporate an accelerometer which may be used to capture the acceleration signals produced as a result of owner's gait. Nowadays, gait identification in basis of acceleration signals is being considered as a new biometric technique which allows blocking the device when another person is carrying it. Although distance based approaches as Euclidean distance or dynamic time warping have been applied to solve this identification problem, they show difficulties when dealing with gaits at different speeds. For this reason, in this paper, a method to extract an average template from instances of the gait at different velocities is presented. This method has been tested with the gait signals of 34 subjects while walking at different motion speeds (slow, normal and fast) and it has shown to improve the performance of Euclidean distance and classical dynamic time warping.