bluuebunny/crossref_metadata_2025 huggingface dataset:
The nsp1, nsp13, and M Proteins Contribute to the Hepatotropism of Murine Coronavirus JHM.WU
Authors: Zhang Rong , Li Yize , Cowley Timothy J. , Steinbrenner Adam D. , Phillips Judith M. , Yount Boyd L. , Baric Ralph S. , Weiss Susan R.
Published: January 2015

Mouse hepatitis virus (MHV) isolates JHM.WU and JHM.SD promote severe central nervous system disease. However, while JHM.WU replicates robustly and induces hepatitis, JHM.SD fails to replicate or induce pathology in the liver. These two JHM variants encode homologous proteins with few polymorphisms, and little is known about which viral proteins(s) is responsible for the liver tropism of JHM.WU. We constructed reverse genetic systems for JHM.SD and JHM.WU and, utilizing these full-length cDNA clones, constructed chimeric viruses and mapped the virulence factors involved in liver tropism. Exchanging the spike proteins of the two viruses neither increased replication of JHM.SD in the liver nor attenuated JHM.WU. By further mapping, we found that polymorphisms in JHM.WU structural protein M and nonstructural replicase proteins nsp1 and nsp13 are essential for liver pathogenesis. M protein and nsp13, the helicase, of JHM.WU are required for efficient replication
in vitro
and in the liver
in vivo
. The JHM.SD nsp1 protein contains a K194R substitution of Lys194, a residue conserved among all other MHV strains. The K194R polymorphism has no effect on
in vitro
replication but influences hepatotropism, and introduction of R194K into JHM.SD promotes replication in the liver. Conversely, a K194R substitution in nsp1 of JHM.WU or A59, another hepatotropic strain, significantly attenuates replication of each strain in the liver and increases IFN-β expression in macrophages in culture. Our data indicate that both structural and nonstructural proteins contribute to MHV liver pathogenesis and support previous reports that nsp1 is a
Betacoronavirus
virulence factor.

IMPORTANCE
The
Betacoronavirus
genus includes human pathogens, some of which cause severe respiratory disease. The spread of severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) into human populations demonstrates the zoonotic potential of emerging coronaviruses, and there are currently no vaccines or effective antivirals for human coronaviruses. Thus, it is important to understand the virus-host interaction that regulates coronavirus pathogenesis. Murine coronavirus infection of mice provides a useful model for the study of coronavirus-host interactions, including the determinants of tropism and virulence. We found that very small changes in coronavirus proteins can profoundly affect tropism and virulence. Furthermore, the hepatotropism of MHV-JHM depends not on the spike protein and viral entry but rather on a combination of the structural protein M and nonstructural replicase-associated proteins nsp1 and nsp13, which are conserved among betacoronaviruses. Understanding virulence determinants will aid in the design of vaccines and antiviral strategies.
Sp1 Sites in the Noncoding Control Region of BK Polyomavirus Are Key Regulators of Bidirectional Viral Early and Late Gene Expression
Authors: Bethge Tobias , Hachemi Helen A. , Manzetti Julia , Gosert Rainer , Schaffner Walter , Hirsch Hans H.
Published: January 2015

In kidney transplant patients with BK polyomavirus (BKPyV) nephropathy, viral variants arise bearing rearranged noncoding control regions (
rr
-NCCRs) that increase viral early gene expression, replicative fitness, and cytopathology.
rr
-NCCRs result from various deletions and duplications of archetype NCCR (
ww
-NCCR) sequences, which alter transcription factor binding sites (TFBS). However, the role of specific TFBS is unclear. We inactivated 28 TFBS in the archetype NCCR by selective point mutations and examined viral gene expression in bidirectional reporter constructs. Compared to the archetype, group 1 mutations increased viral early gene expression similar to
rr
-NCCR and resulted from inactivating one
Sp1
or one
Ets1
TFBS near the late transcription start site (TSS). Group 2 mutations conferred intermediate early gene activation and affected NF1, YY1, and p53 sites between early and late TSS. Group 3 mutations decreased early and late gene expression and included two other
Sp1
sites near the early TSS. Recombinant viruses bearing group 1 NCCRs showed increased replication in human renal epithelial cells similar to clinical
rr
-NCCR variants. Group 2 and 3 viruses showed intermediate or no replication, respectively. A literature search revealed unnoticed group 1 mutations in BKPyV nephropathy, hemorrhagic cystitis, and disseminated disease.

IMPORTANCE
The NCCRs of polyomaviruses mediate silent persistence of the viral genome as well as the appropriately timed (re)activation of the viral life cycle. This study indicates that the basal BKPyV NCCR is critically controlled by a hierarchy of single TFBS in the archetype NCCR that direct, modulate, and execute the bidirectional early and late viral gene expression. The results provide new insights into how BKPyV NCCR functions as a viral sensor of host cell signals and shed new light on how transcription factors like Sp1 control bidirectional viral gene expression and contribute to replication and pathology.
Long-Term Control of Simian Immunodeficiency Virus (SIV) in Cynomolgus Macaques Not Associated with Efficient SIV-Specific CD8+T-Cell Responses
Authors: Bruel Timothée , Hamimi Chiraz , Dereuddre-Bosquet Nathalie , Cosma Antonio , Shin So Youn , Corneau Aurélien , Versmisse Pierre , Karlsson Ingrid , Malleret Benoit , Targat Brice , Barré-Sinoussi Françoise , Le Grand Roger , Pancino Gianfranco , Sáez-Cirión Asier , Vaslin Bruno
Published: January 2015

The spontaneous control of human and simian immunodeficiency viruses (HIV/SIV) is typically associated with specific major histocompatibility complex (MHC) class I alleles and efficient CD8+T-cell responses, but many controllers maintain viral control despite a nonprotective MHC background and weak CD8+T-cell responses. Therefore, the contribution of this response to maintaining long-term viral control remains unclear. To address this question, we transiently depleted CD8+T cells from five SIV-infected cynomolgus macaques with long-term viral control and weak CD8+T-cell responses. Among them, only one carried the protective MHC allele H6. After depletion, four of five controllers experienced a transient rebound of viremia. The return to undetectable viremia was accompanied by only modest expansion of SIV-specific CD8+T cells that lacked efficient SIV suppression capacityex vivo. In contrast, the depletion was associated with homeostatic activation/expansion of CD4+T cells that correlated with viral rebound. In one macaque, viremia remained undetectable despite efficient CD8+cell depletion and inducible SIV replication from its CD4+T cellsin vitro. Altogether, our results suggest that CD8+T cells are not unique contributors to the long-term maintenance of low viremia in this SIV controller model and that other mechanisms, such as weak viral reservoirs or control of activation, may be important players in control.

IMPORTANCESpontaneous control of HIV-1 to undetectable levels is associated with efficient anti-HIV CD8+T-cell responses. However, in some cases, this response fades over time, although viral control is maintained, and many HIV controllers (weak responders) have very low frequencies of HIV-specific CD8+T cells. In these cases, the importance of CD8 T cells in the maintenance of HIV-1 control is questionable. We developed a nonhuman primate model of durable SIV control with an immune profile resembling that of weak responders. Transient depletion of CD8+cells induced a rise in the viral load. However, viremia was correlated with CD4+T-cell activation subsequent to CD8+cell depletion. Regain of viral control to predepletion levels was not associated with restoration of the anti-SIV capacities of CD8+T cells. Our results suggest that CD8+T cells may not be involved in maintenance of viral control in weak responders and highlight the fact that additional mechanisms should not be underestimated.
Patterns of bruising in preschool children—a longitudinal study
Authors: Kemp Alison M , Dunstan Frank , Nuttall Diane , Hamilton M , Collins Peter , Maguire Sabine
Published: January 2015

Introduction

This study aims to identify the prevalence and pattern of bruises in preschool children over time, and explore influential variables

Methods

Prospective longitudinal study of children (<6 years) where bruises were recorded on a body chart, weekly for up to 12 weeks. The number and location of bruises were analysed according to development. Longitudinal analysis was performed using multilevel modelling.

Results

3523 bruises recorded from 2570 data collections from 328 children (mean age 19 months); 6.7% of 1010 collections from premobile children had at least one bruise (2.2% of babies who could not roll over and 9.8% in those who could), compared with 45.6% of 478 early mobile and 78.8% of 1082 walking child collections. The most common site affected in all groups was below the knees, followed by ‘facial T’ and head in premobile and early mobile. The ears, neck, buttocks, genitalia and hands were rarely bruised (<1% of all collections). None of gender, season or the level of social deprivation significantly influenced bruising patterns, although having a sibling increased the mean number of bruises. There was considerable variation in the number of bruises recorded between different children which increased with developmental stage and was greater than the variation between numbers of bruises in collections from the same child over time.

Conclusions

These data should help clinicians understand the patterns of ‘everyday bruising’ and recognise children who have an unusual numbers or distribution of bruises who may need assessment for physical abuse or bleeding disorders.
Epidemiology of psoriasis and palmoplantar pustulosis: a nationwide study using the Japanese national claims database
Authors: Kubota Kiyoshi , Kamijima Yukari , Sato Tsugumichi , Ooba Nobuhiro , Koide Daisuke , Iizuka Hajime , Nakagawa Hidemi
Published: January 2015

Objective

The primary objective was to estimate the national prevalence of psoriasis and palmoplantar pustulosis (PPP) in Japan. Secondary objectives were to determine (1) whether psoriasis and PPP disease activity varies by season, and (2) whether disease severity is associated with concurrent diabetes mellitus, hyperlipidaemia and hypertension.

Settings

Patients with a psoriasis or PPP diagnosis code between April 2010 and March 2011 were identified using a Japanese national database.

Participants

565 903 patients with psoriasis or PPP were identified. No patient was excluded.

Primary and secondary outcome measures

National prevalence was calculated using census data. We estimated the difference in the proportion of patients who used healthcare services, as a proxy for disease activity, between the hot and cold seasons and the difference in the standardised prevalence of comorbidities between severe and mild disease. The measures were estimated separately for the two broad disease categories of psoriasis and PPP but not in all patients as planned because the two disease categories had major differences.

Results

The national prevalence of psoriasis and PPP was 0.34% (95% CI 0.34% to 0.34%) and 0.12% (0.12% to 0.12%), respectively. The difference in the proportion of patients who used healthcare services in the hot compared to the cold season was −0.3% (−0.5% to −0.1%) for psoriasis and 10.0% (9.8% to 10.3%) for PPP. The difference in the standardised prevalence between severe and mild psoriasis was 3.1% (2.7% to 3.4%), 3.2% (2.8% to 3.6%) and 5.1% (4.7% to 5.6%) for concurrent diabetes mellitus, hyperlipidaemia and hypertension, respectively. No significant difference in the prevalence of comorbidity was observed for PPP.

Conclusions

The national prevalence, seasonal variation in disease activity and prevalence of comorbidities in Japanese patients with psoriasis and PPP estimated in this descriptive study may be used as basic information for future studies.
Low-dose dexamethasone as a treatment for women with heavy menstrual bleeding: protocol for response-adaptive randomised placebo-controlled dose-finding parallel group trial (DexFEM)
Authors: Warner P , Weir C J , Hansen C H , Douglas A , Madhra M , Hillier S G , Saunders P T K , Iredale J P , Semple S , Walker B R , Critchley H O D
Published: January 2015

Introduction

Heavy menstrual bleeding (HMB) diminishes individual quality-of-life and poses substantial societal burden. In HMB endometrium, inactivation of cortisol (by enzyme 11β hydroxysteroid dehydrogenase type 2 (11βHSD2)), may cause local endometrial glucocorticoid deficiency and hence increased angiogenesis and impaired vasoconstriction. We propose that ‘rescue’ of luteal phase endometrial glucocorticoid deficiency could reduce menstrual bleeding.

Methods and analysis

DexFEM is a double-blind response-adaptive parallel-group placebo-controlled trial in women with HMB (108 to be randomised), with active treatment the potent oral synthetic glucocorticoid dexamethasone, which is relatively resistant to 11βHSD2 inactivation. Participants will be aged over 18 years, with mean measured menstrual blood loss (MBL) for two screening cycles ≥50 mL. The primary outcome is reduction in MBL from screening. Secondary end points are questionnaire assessments of treatment effect and acceptability. Treatment will be for 5 days in the mid-luteal phases of three treatment menstrual cycles. Six doses of low-dose dexamethasone (ranging from 0.2 to 0.9 mg twice daily) will be compared with placebo, to ascertain optimal dose, and whether this has advantage over placebo. Statistical efficiency is maximised by allowing randomisation probabilities to ‘adapt’ at five points during enrolment phase, based on the response data available so far, to favour doses expected to provide greatest additional information on the dose–response. Bayesian Normal Dynamic Linear Modelling, with baseline MBL included as covariate, will determine optimal dose (re reduction in MBL). Secondary end points will be analysed using generalised dynamic linear models. For each dose for all end points, a 95% credible interval will be calculated for effect versus placebo.

Ethics and dissemination

Dexamethasone is widely used and hence well-characterised safety-wise. Ethical approval has been obtained from Scotland A Research Ethics Committee (12/SS/0147). Trial findings will be disseminated via open-access peer-reviewed publications, conferences, clinical networks, public lectures, and our websites.

Trial registration number

ClinicalTrials.govNCT01769820; EudractCT 2012-003405-98.
Increasing the number of patients receiving information about transition to end-of-life care: the effect of a half-day physician and nurse training
Authors: Martinsson L , Heedman P-A , Eriksson M , Tavelin B , Axelsson B
Published: January 2015

Introduction

Honest prognostication and information for patients are important parts of end-of-life care. This study examined whether an educational intervention could increase the proportion of patients who received information about the transition to end-of-life (ITEOL care).

Method

Two municipalities (in charge of nursing homes) and two hospitals were randomised to receive an interactive half-day course about ITEOL for physicians and nurses. The proportion of patients who received ITEOL was measured with data from the Swedish Register of Palliative Care (SRPC). Patients were only included if they died an expected death and maintained their ability to express their will until days or hours before their death. Four hospitals and four municipalities were assigned controls, matched by hospital size, population and proportion of patients receiving ITEOL at baseline.

Results

The proportion of patients in the intervention group who received ITEOL increased from 35.1% (during a 6-month period before the intervention) to 42% (during a 6-month period after the intervention). The proportion in the control group increased from 30.4% to 33.7%. The effect of the intervention was significant (p=0.005) in a multivariable model adjusted for time, age, gender and cause of death.

Conclusion

More patients at end-of-life received ITEOL after an educative half-day intervention directed to physicians and nurses.
Advances in internal fixation locking plates
Authors: Arthurs Gareth
Published: January 2015

One of the biggest advances in small animal orthopaedics over the last few years has been the development and availability of locking plate systems. The Locking Compression Plate was introduced to human orthopaedics at the beginning of the millennium, and subsequently to veterinary orthopaedics a few years later in 2004. Since that time, its use has become common in specialist orthopaedic practice, and a number of other locking plate systems have been developed that are starting to be used in general practice. This article is an introduction to the theory and practice of locking plates.
Schmallenberg virus: an update
Authors: Roger Paul
Published: January 2015

Much has been learned about Schmallenberg virus since it first appeared in Northern Europe three years ago, but a number of uncertainties remain. This article looks at what has happened over the past 12 months and where that leaves us for the coming year.
A panel of nine cerebrospinal fluid biomarkers may identify patients with atypical parkinsonian syndromes
Authors: Magdalinou N K , Paterson R W , Schott J M , Fox N C , Mummery C , Blennow K , Bhatia K , Morris H R , Giunti P , Warner T T , de Silva R , Lees A J , Zetterberg H
Published: January 2015

Background

Patients presenting with parkinsonian syndromes share many clinical features, which can make diagnosis difficult. This is important as atypical parkinsonian syndromes (APSs) such as progressive supranuclear palsy (PSP), multiple system atrophy (MSA) and corticobasal syndrome (CBS) carry a poor prognosis, compared with patients with Parkinson's disease (PD). In addition, there is overlap between APS and dementia diseases, such as Alzheimer's disease (AD) and frontotemporal dementia (FTD).

Objective

To use a panel of cerebrospinal fluid (CSF) biomarkers to differentiate patients with APS from PD and dementia.

Methods

A prospective cohort of 160 patients and 30 control participants were recruited from a single specialist centre. Patients were clinically diagnosed according to current consensus criteria. CSF samples were obtained from patients with clinical diagnoses of PD (n=31), PSP (n=33), CBS (n=14), MSA (n=31), AD (n=26) and FTD (n=16). Healthy, elderly participants (n=30) were included as controls. Total τ (t-τ), phosphorylated τ (p-τ), β-amyloid 1–42 (Aβ42), neurofilament light chain (NFL), α-synuclein (α-syn), amyloid precursor protein soluble metabolites α and β (soluble amyloid precursor protein (sAPP)α, sAPPβ) and two neuroinflammatory markers (monocyte chemoattractant protein-1 and YKL-40) were measured in CSF. A reverse stepwise regression analysis and the false discovery rate procedure were used.

Results

CSF NFL (p<0.001), sAPPα (p<0.001) and a-syn (p=0.003) independently predicted diagnosis of PD versus APS. Together, these nine biomarkers could differentiate patients with PD from APS with an area under the curve of 0.95 and subtypes of APS from one another. There was good discriminatory power between parkinsonian groups, dementia disorders and healthy controls.

Conclusions

A panel of nine CSF biomarkers was able to differentiate APS from patients with PD and dementia. This may have important clinical utility in improving diagnostic accuracy, allowing better prognostication and earlier access to potential disease-modifying therapies.
Effects of pile shape in improving the performance of monopiles embedded in onshore clays
Authors: Pedram B.
Published: January 2015

This paper presents the results from a series of three-dimensional finite element analyses, which examine the benefits of adopting square pile–tower structures instead of circular monopiles. The advantages of square monopiles are brought out in this paper through a parametric study with a Tresca soil model, where the shear strength and modulus of elasticity varied with depth and the pile–tower structures were modelled as an elastoplastic material. The effects of pile diameter, pile thickness, eccentricity, and pile length for free-head pile–towers embedded in lightly overconsolidated and heavily overconsolidated clays were investigated. From the results of the numerical models, it is clear that the ultimate lateral capacity and stiffness of square pile–tower structures are substantially higher than of circular structures embedded in clay layers. Moreover, the amount of rotation and displacement of square structures are not significantly affected compared to circular monopiles.
Analytical method for determining polycyclic aromatic hydrocarbon pollutants using ultrafast liquid chromatography with fluorescence detection and the recent column packed with the new 5 μm Kinetex-C18 core-shell particles
Authors: Goulas Anaïs , Louvel Brice , Waterlot Christophe
Published: January 2015

An ultrafast liquid chromatography method with fluorescence detection has been optimized for the determination of 15 polycyclic aromatic hydrocarbons (PAHs) using a recent Kinetex-C18 column (250 mm × 4.6 mm). This column has been recently packed with a new brand of porous shell particles with an average particle size of 5 μm to separate various compounds by liquid chromatography, operating at very low pressure. After optimization of the analytical procedure, the separation of the 15 PAHs in spiked tap water samples was achieved without coeluted products in 21.5 min at 16 °C using an aqueous/acetonitrile mobile phase under gradient concentrations with a very low flow rate (0.7–1.0 mL min−1) and low pressure values (870–1590 psi = 60–110 bar), all of these conditions being interesting from an economic point of view. The synchronization of wavelength time changing and the elution time of each compound was performed to avoid baseline deviation. The validation of the whole of the experimental procedure was conducted taking into consideration the following parameters: calibration curve, linearity, limits of detection and quantification, accuracy, sensitivity, precision, and repeatability of the retention time for each PAH. The proposed analytical procedure presented adequate linearity over a concentration range from 0.025 to 10 μg L−1 with a correlation coefficient better than 0.9980. The repeatability (relative standard deviation in percentage, n = 5) of the retention time for the different PAHs investigated ranged from 0.03% to 0.34% and the limit of detection was under 0.6 μg L−1 for most PAHs (excepted for indeno[1,2,3-c,d]pyrene, limit of detection = 1.71 μg L−1). The intraday and interday precisions were below 4%. The recovery of PAH in spiked tap water samples was variable, ranging from 96% to 109%, with relative standard deviation between 0.2% and 4.8%, depending on PAHs and their concentration levels.
A facile approach for the synthesis of 1,3-di- and 1,2,3-tri-substituted indolizines
Authors: Tan Jun , Yang Yiwen , Chen Jie , Kuang Chunxiang
Published: January 2015

A convenient synthesis of 1,3-di- and 1,2,3-tri-substituted indolizines involving the multicomponent reaction of pyridinium salt (or quinolinium salt), olefine acid, and 1,2-dichloroethane has been achieved. The process proceeds smoothly in moderate to high yields.
Deletion of thePDR16gene influences the plasma membrane properties of the yeastKluyveromyces lactis
Authors: Toth Hervay Nora , Goffa Eduard , Svrbicka Alexandra , Simova Zuzana , Griac Peter , Jancikova Iva , Gaskova Dana , Morvova Marcela , Sikurova Libusa , Gbelska Yvetta
Published: January 2015

The plasma membrane is the first line of cell defense against changes in external environment, thus its integrity and functionality are of utmost importance. The plasma membrane properties depend on both its protein and lipid composition. The PDR16 gene is involved in the control of Kluyveromyces lactis susceptibility to drugs and alkali metal cations. It encodes the homologue of the major K. lactis phosphatidylinositol transfer protein Sec14p. Sec14p participates in protein secretion, regulation of lipid synthesis, and turnover in vivo. We report here that the plasma membrane of the Klpdr16Δ mutant is hyperpolarized and its fluidity is lower than that of the parental strain. In addition, protoplasts prepared from the Klpdr16Δ cells display decreased stability when subjected to hypo-osmotic conditions. These changes in membrane properties lead to an accumulation of radiolabeled fluconazole and lithium cations inside mutant cells. Our results point to the fact that the PDR16 gene of K. lactis (KlPDR16) influences the plasma membrane properties in K. lactis that lead to subsequent changes in susceptibility to a broad range of xenobiotics.
Analysis of MHD flow of Burgers’ fluid with heat transfer in helical screw rheometer
Authors: Haroon T. , Siddiqui A.M. , Zeb M.
Published: January 2015

This paper aims to study the influence of Hall current and heat transfer on the magnetohydrodynamics (MHD) flow of an electrically conducting, incompressible Burgers’ fluid in a helical screw rheometer. The screw and barrel are electrically insulated and kept at two different constant temperatures. A uniform magnetic field is applied perpendicular to the flow. Exact solutions are obtained for the velocity profile, volume flow rate, temperature distribution and rate of heat transfer. Expressions for the shear and normal stress components are also calculated. It is observed that the Burgers’ fluid parameters contribute in normal and tangential stresses, only. The effects of Hall parameter, Hartmann number, pressure distribution, and Brinkman number are investigated on flow profile, temperature distribution, and heat flux.
103Tc nuclear structure and systematic evolution of states of g9/2 parentage in odd-A 95, 97, 99, 101, 103Tc isotopes
Authors: Zeghib Sadek
Published: January 2015

A systematic study of the evolution of the nuclear structure (at low and medium energies) of odd-A 95–103Tc isotopes is presented. These changes are indeed affected predominantly by changes in deformation and subsequently the position of the Fermi level. Hence a complete study of previously observed positive and negative parity states (at low and medium energies) of 103Tc in the framework of the particle–rotor model is performed. Experimental energies and transition properties will be compared to those predicted by the model calculations. The systematic model calculations show that those rotational “multiplets” emerging as a result of the larger Coriolis mixing, especially among positive-parity Nilsson states of g9/2 parentage in less deformed isotopes 95, 97, 99, 101Tc, are just as natural a prediction of the model as rotational bands built on states of good Ω in well deformed 103Tc (strong coupling) as confirmed experimentally.
Chaplygin scalar field reconstruction of the modified ghost dark energy model
Authors: Karami Kayoomars
Published: January 2015

Within the framework of Einstein gravity, we establish a correspondence between the Chaplygin scalar field model and the modified ghost dark energy model. We consider a spatially non-flat Friedmann–Robertson–Walker universe containing modified ghost dark energy and dark matter that are in interaction with each other. We solve the differential equation governing the dimensionless modified ghost dark energy density parameter numerically. Then we obtain the evolutionary behaviors of both the energy density and equation of state parameters of the modified ghost dark energy. More interesting is that the equation of state parameter at the present time can cross the phantom divide line provided the interaction parameter b2 > 0.15 is compatible with the observations. Furthermore, we reconstruct both the Chaplygin gas scalar field and potential according to the evolutionary behavior of the modified ghost dark energy model.
Measures of node centrality in mobile social networks
Authors: Gao Zhenxiang , Shi Yan , Chen Shanzhi
Published: January 2015

Mobile social networks exploit human mobility and consequent device-to-device contact to opportunistically create data paths over time. While links in mobile social networks are time-varied and strongly impacted by human mobility, discovering influential nodes is one of the important issues for efficient information propagation in mobile social networks. Although traditional centrality definitions give metrics to identify the nodes with central positions in static binary networks, they cannot effectively identify the influential nodes for information propagation in mobile social networks. In this paper, we address the problems of discovering the influential nodes in mobile social networks. We first use the temporal evolution graph model which can more accurately capture the topology dynamics of the mobile social network over time. Based on the model, we explore human social relations and mobility patterns to redefine three common centrality metrics: degree centrality, closeness centrality and betweenness centrality. We then employ empirical traces to evaluate the benefits of the proposed centrality metrics, and discuss the predictability of nodes' global centrality ranking by nodes' local centrality ranking. Results demonstrate the efficiency of the proposed centrality metrics.
Quantum gravity and renormalization
Authors: Anselmi Damiano
Published: January 2015

The properties of quantum gravity are reviewed from the point of view of renormalization. Various attempts to overcome the problem of non-renormalizability are presented, and the reasons why most of them fail for quantum gravity are discussed. Interesting possibilities come from relaxing the locality assumption, which also can inspire the investigation of a largely unexplored sector of quantum field theory. Another possibility is to work with infinitely many independent couplings, and search for physical quantities that only depend on a finite subset of them. In this spirit, it is useful to organize the classical action of quantum gravity, determined by renormalization, in a convenient way. Taking advantage of perturbative local field redefinitions, we write the action as the sum of the Hilbert term, the cosmological term, a peculiar scalar that is important only in higher dimensions, plus invariants constructed with at least three Weyl tensors. We show that the FRLW configurations, and many other locally conformally flat metrics, are exact solutions of the field equations in arbitrary dimensions d>3. If the metric is expanded around such configurations the quadratic part of the action is free of higher-time derivatives. Other well-known metrics, such as those of black holes, are instead affected in nontrivial ways by the classical corrections of quantum origin.
A Compressed-Domain Image Filtering and Re-Ranking Approach for Multi-Agent Image Retrieval
Authors: Zhang Jing , Li Zhenwei , Zhuo Li , Liu Xin , Yang Ying
Published: January 2015

For the limited transmission capacity and compressed images in the network environment, a compressed-domain image filtering and re-ranking approach for multi-agent image retrieval is proposed in this paper. Firstly, the distributed image retrieval platform with multi-agent is constructed by using Aglet development system, the lifecycle and the migration mechanism of agent is designed and planned for multi-agent image retrieval by using the characteristics of mobile agent. Then, considering the redundant image brought by distributed multi-agent retrieval, the duplicate images in distributed retrieval results are filtered based on the perceptual hashing feature extracted in the compressed-domain. Finally, weight-based hamming distance is utilized to re-rank the retrieval results. The experimental results show that the proposed approach can effectively filter the duplicate images in distributed image retrieval results as well as improve the accuracy and speed of compressed-domain image retrieval.
The smooth surfaces in ℙ4 with few apparent triple points
Authors: Sierra José Carlos
Published: January 2015

We classify smooth complex projective surfaces in [Formula: see text] with [Formula: see text] apparent triple points, thus recovering and extending the results of Ascione [Sulle superficie immerse in un [Formula: see text], le cui trisecanti costituiscono complessi di [Formula: see text] ordine, Atti Accad. Naz. Lincei Rend. Cl. Sci. Fis. Mat. Natur.[Formula: see text]5[Formula: see text] 6 (1897) 162–169] and Severi [Intorno ai punti doppi impropri di una superficie generale dello spazio a quattro dimensioni, e a’ suoi punti tripli apparenti, Rend. Circ. Mat. Palermo 15 (1901) 33–51] for [Formula: see text], Marletta [Le superficie generali dell’ [Formula: see text] dotate di due punti tripli apparenti, Rend. Circ. Mat. Palermo 34 (1912) 179–186] for [Formula: see text], and Aure [The smooth surfaces in [Formula: see text] without apparent triple points, Duke Math. J. 57 (1988) 423–430] for [Formula: see text]. This is done thanks to a new projective character that can be introduced as a consequence of the main result of [K. Ranestad, On smooth plane curve fibrations in [Formula: see text], in Geometry of Complex Projective Varieties, Sem. Conf., Vol. 9 (Mediterranean, 1993), pp. 243–255; J. C. Sierra and A. L. Tironi, Some remarks on surfaces in [Formula: see text] containing a family of plane curves, J. Pure Appl. Algebra 209 (2007) 361–369; V. Beorchia and G. Sacchiero, Surfaces in [Formula: see text] with a family of plane curves, J. Pure Appl. Algebra 213 (2009) 1750–1755]. Going a bit further, we obtain some bounds on the Euler characteristic [Formula: see text] in terms of the degree [Formula: see text] and the sectional genus [Formula: see text] of a smooth surface in [Formula: see text]. For [Formula: see text], these bounds were first obtained in [A. B. Aure and K. Ranestad, The smooth surfaces of degree [Formula: see text] in [Formula: see text], in Complex Projective Geometry, London Mathematical Society Lecture Note Series, Vol. 179 (Cambridge University Press, Cambridge, 1992), pp. 32–46; K. Ranestad, On smooth surfaces of degree [Formula: see text] in the projective fourspace, Ph.D. thesis, Oslo (1988); S. Popescu, On smooth surfaces of degree [Formula: see text] in the projective fourspace, Dissertation, Saarbrücken (1993)]. Here we give a different argument based on liaison that works also for [Formula: see text] and that allows us to determine the triples [Formula: see text] of the smooth surfaces with [Formula: see text] apparent triple points.
Monotone quantities involving a weighted σk integral along inverse curvature flows
Authors: Kwong Kwok-Kun , Miao Pengzi
Published: January 2015

We give a family of monotone quantities along smooth solutions to the inverse curvature flows in Euclidean spaces. We also derive a related geometric inequality for closed hypersurfaces with positive kth mean curvature.
A Hilbert manifold structure on the Weil–Petersson class Teichmüller space of bordered Riemann surfaces
Authors: Radnell David , Schippers Eric , Staubach Wolfgang
Published: January 2015

We consider bordered Riemann surfaces which are biholomorphic to compact Riemann surfaces of genus g with n regions biholomorphic to the disk removed. We define a refined Teichmüller space of such Riemann surfaces (which we refer to as the WP-class Teichmüller space) and demonstrate that in the case that 2g + 2 - n > 0, this refined Teichmüller space is a Hilbert manifold. The inclusion map from the refined Teichmüller space into the usual Teichmüller space (which is a Banach manifold) is holomorphic. We also show that the rigged moduli space of Riemann surfaces with non-overlapping holomorphic maps, appearing in conformal field theory, is a complex Hilbert manifold. This result requires an analytic reformulation of the moduli space, by enlarging the set of non-overlapping mappings to a class of maps intermediate between analytically extendible maps and quasiconformally extendible maps. Finally, we show that the rigged moduli space is the quotient of the refined Teichmüller space by a properly discontinuous group of biholomorphisms.
Blow-up for sign-changing solutions of the critical heat equation in domains with a small hole
Authors: Ianni Isabella , Musso Monica , Pistoia Angela
Published: January 2015

We consider the critical heat equation [Formula: see text] in [Formula: see text] where [Formula: see text] is a smooth bounded domain in [Formula: see text] and [Formula: see text] is a ball of [Formula: see text] of center [Formula: see text] and radius [Formula: see text] small. We show that if [Formula: see text] is small enough, then there exists a sign-changing stationary solution [Formula: see text] of (CH) such that the solution of (CH) with initial value [Formula: see text] blows up if [Formula: see text] is sufficiently small. This shows, in particular, that the set of the initial conditions for which the solution of (CH) is global and bounded is not star-shaped.
Hamiltonian dynamics of 5D Kalb–Ramond theories with a compact extra dimension
Authors: Escalante Alberto , López-Villanueva A.
Published: January 2015

A detailed Hamiltonian analysis for a 5D Kalb–Ramond, massive Kalb–Ramond and Stüeckelberg Kalb–Ramond theories with an extra compact dimension is performed. We develop a complete constraint program, then we quantize the theory by constructing the Dirac brackets. From the gauge transformations of the theories, we fix a particular gauge and we find pseudo-Goldstone bosons in Kalb–Ramond and Stüeckelberg Kalb–Ramond systems. Finally we discuss some remarks and prospects.
Probing the physical and mathematical structure of f(R)-gravity by PSR J0348 + 0432
Authors: De Laurentis Mariafelicia , De Martino Ivan
Published: January 2015

There are several approaches to extend General Relativity in order to explain the phenomena related to the Dark Matter and Dark Energy. These theories, generally called Extended Theories of Gravity, can be tested using observations coming from relativistic binary systems as PSR J0348 + 0432. Using a class of analytical f(R)-theories, one can construct the first time derivative of orbital period of the binary systems starting from a quadrupolar gravitational emission. Our aim is to set boundaries on the parameters of the theory in order to understand if they are ruled out, or not, by the observations on PSR J0348 + 0432. Finally, we have computed an upper limit on the graviton mass showing that agree with constraint coming from other observations.
Threshold analysis for epidemic models with high-risk immunization on networks
Authors: Wu Qingchu , Chen Shufang
Published: January 2015

In this paper, an SIRS epidemic model with high-risk immunization was investigated, where a susceptible neighbor of an infected node is immunized with rate h. Through analyzing the discrete-time model, we found that the epidemic threshold above which an epidemic can prevail and persist in a population is inversely proportional to 1 - h value. We also studied the continuous-time epidemic model and obtained a different result: the epidemic threshold does not depend on the immunization parameter h. Our results suggest that the difference between the discrete-time epidemic model and the continuous-time epidemic model exists in the high-risk immunization.
Improving dielectric properties and thermal conductivity of polymer composites withCaCu3Ti4O12and β-SiChybrid fillers
Authors: Ouyang Xin , Cao Peng , Zhang Weijun , Huang Zhaohui , Gao Wei
Published: January 2015

In this paper, we report a series of homogeneous polymeric composites with enhanced dielectric properties and thermal conductivity. The composites were constituted of polyvinylidene fluorides (PVDFs) matrix and CaCu3Ti4O12(CCTO) monolithic or CCTO/β- SiC hybrid fillers, and prepared by simple melt blending and hot moulding technique. The influence of different types of fillers and their composition on the dielectric response and thermal conductivity of the obtained composites was studied. Results show that hybrid loading is preferred and a reasonable combination of thermal conductivity (0.80 W⋅m-1⋅K-1), dielectric constant (∼50) and dielectric loss (∼0.07) at 103Hz was achieved in the PVDF composite containing 40 vol.% CCTO and 10 vol.% β- SiC . The strong dipolar and interfacial polarization derived from the fillers are responsible for the enhancement of the dielectric constant, while the formation of thermally conductive networks/chains by β- SiC whiskers contributes to the improved thermal conductivity.
Effects of hydrothermal temperature on the morphology and photoelectrocatalytic performance of TiO2-based nanomaterials photoelectrode
Authors: Li Dong , Yu Xiujuan , Cheng Xiuwen
Published: January 2015

TiO 2-based nanomaterials (BNMs) photoelectrode was successfully synthesized via a facile and controllable hydrothermal procedure. The as-prepared TiO 2-BNMs photoelectrode was characterized by field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD). The resulting TiO 2-BNMs samples assembled by different morphologies were obtained through changing hydrothermal temperature that were: (i) One-dimensional (relative to nanosheets) nanobelts at 140°C, (ii) two-dimensional nanosheets at 160–180°C and (iii) three-dimensional network nanowires at 200–220°C. Structural investigation of the obtained nanomaterials revealed that the content of anatase increased as increasing the apparent dimensionality of the materials. The photoelectrochemical performance of TiO 2-BNMs photoelectrode was elucidated by comparative investigation on the electron transport and electron–hole (e-/h+) recombination in TiO 2-BNMs sample with typically morphology. The photoelectrochemical performance of the TiO 2-BNMs sample was obviously dependent on the morphology. Compared to the nanobelts and the network nanowires structure, the two-dimensional nanosheets displayed the more effective photogenerated electron transfer and reduced electron–hole recombination rate. Moreover, two-dimensional nanosheets had significantly enhanced photoelectrocatalytic efficiency for degradation of methyl orange (MO).
Synthesis of Ag decorated graphene-hierarchical TiO2 nanocomposite with enhanced photocatalytic activity
Authors: Fu Li , Zheng Yuhong , Fu Zhuxian , Cai Wen , Yu Jinpin
Published: January 2015

Reduced graphene oxide (RGO) wrapped TiO 2/ Ag ternary nanocomposite was synthesized via a wet chemical method. The synthesized nanocomposite was characterized using UV-Vis spectroscopy, Raman spectroscopy, photoluminescence spectroscopy, Scanning electron microscope (SEM), Energy-dispersive X-ray spectroscopy (EDX) and X-ray Diffraction (XRD). The average size of RGO wrapped TiO 2 and deposited Ag nanoparticles were 3.2 μm and 48 nm, respectively. Due to the highly facilitated electron transport by the synergistic effect between RGO sheets and Ag nanoparticles, the TiO 2/ RGO / Ag nanocomposite exhibited a significant enhancement of photocatalytic activity towards degradation of methylene blue under UV light.
Energetic and thermal properties of tilt grain boundaries in graphene/hexagonal boron nitride heterostructures
Authors: Wang Mingchao , Zhang Guangping , Peng Huisheng , Yan Cheng
Published: January 2015

Graphene/hexagonal boron nitride (G/h-BN) heterostructure has attracted tremendous research efforts owing to its great potential for applications in nanoscale electronic devices. In such hybrid materials, tilt grain boundaries (GBs) between graphene and h-BN grains may have unique physical properties, which have not been well understood. Here we have conducted non-equilibrium molecular dynamics simulations to study the energetic and thermal properties of tilt GBs in G/h-BN heterostructures. The effect of misorientation angles of tilt GBs on both GB energy and interfacial thermal conductance are investigated.
The magnetic states and Labyrinth ordering in 2D lattices of ising spins with RKKY Interaction
Authors: Nefedev Konstantin , Belokon Valery , Kapitan Vitalii , Dyachenko Olga
Published: January 2015

The numerical simulation of 2D simple square lattice of Ising superspins, that interact via the Ruderman–Kittel–Kasuya–Yosida (RKKY) exchange interaction is performed. It is found, that at low temperatures in the researched systems predominantly realized labyrinth domain structure. The modeled image of magnetization distribution does not coincide with the image of energy distribution. Hysteresis loops of the samples and labyrinth domain structures similarly obtained by Monte Carlo method, are also observed in physical experiments.
Lipolytic inhibitor G0/G1 switch gene 2 inhibits reactive oxygen species production and apoptosis in endothelial cells
Authors: Wang Yinfang , Zhang Yahui , Zhu Yichun , Zhang Peng
Published: January 2015

G0/G1 switch gene 2 (G0S2), a novel target gene of peroxisome proliferator-activated receptor, is highly expressed in fat tissues. G0S2 acts as proapoptotic factor toward human cancer cells. Endothelial cell (EC) apoptosis may be an initiating event in the development of atherosclerosis. However, the expression and function of G0S2 in vascular ECs remain unknown. Here, we reported for the first time that G0S2 is expressed in arterial ECs. Ectopic expression of G0S2 increased neutral lipid accumulation in cultured ECs. However, G0S2 prevented ECs from serum-free starvation stress- and hydrogen peroxide (H2O2)-induced apoptosis. G0S2 blocked the H2O2-induced dissipation of mitochondrial membrane potential. G0S2 decreased the release of cytochrome c from mitochondria into the cytosol, followed by activation of caspase-9 and caspase-3. The anti-apoptotic effect of G0S2 was Bcl-2 and adipose triglyceride lipase independent. In contrast, gene silence of G0S2 increased serum-free starvation stress-induced EC apoptosis and decreased the formation of capillary-like structures. We further found that G0S2 couples with the F0F1-ATP synthase in ECs. Levels of ATP were elevated, whereas reactive oxygen species levels were reduced in G0S2-expressing ECs. G0S2 can inhibit endothelial denudation secondary to H2O2-induced injury to ECs in vivo. These results indicate that G0S2 acts as a prosurvival molecule in ECs. Taken together, our results indicate that G0S2 has a protective function in ECs and may be a potential target for the treatment of cardiovascular diseases associated with reactive oxygen species-induced EC injury, such as atherosclerosis and restenosis.