bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimal colour‐based mean shift algorithm for tracking objects
Authors: An Xiaowei , Kim Jaedo , Han Youngjoon
Published: May 2014

The mean‐shift method is widely used to locate a target object quickly in sequential images. The mean‐shift algorithm takes advantage of a colour distribution with a uniform quantisation. However, the quantisation method ignores the close relationship of colour statistics. The uniform distribution also results in a colour histogram with many empty bins, which introduces additional computation cost in the tracking procedure. To reduce the number of these redundant, empty bins, the authors present a new optimal colour‐based, mean‐shift algorithm for tracking objects. In the proposed method, the optimal colours are extracted by a histogram agglomeration, which clusters three‐dimensional (3D) colour histogram bins with the frequency ratios of 3D colour values. After obtaining optimal colours in a RGB colour histogram, the target image is represented by the indices of the optimal colours. The mean‐shift algorithm thus creates a confidence map in a candidate image based on the optimal colour histogram in the target image. It then finds the peak of the confidence map near the previous position of an object area. Comparative experiments with the conventional mean‐shift method showed that our method has the advantages of decreased processing time and improved tracking accuracy.
Local feature fitting active contour for segmenting vessels in angiograms
Authors: Taghizadeh Dehkordi Maryam , Doost Hoseini Ali Mohamad , Sadri Saeed , Soltanianzadeh Hamid
Published: May 2014

An active contour model for vascular segmentation has been proposed, by defining a new, local, feature fitting, energy function. A vesselness filter is applied to the image in a directional Hessian‐based framework. The filter output, as a feature, expresses the degree of the correspondence of each pixel to the vessel structure. By using intensity information obtained from local regions, the proposed model is able to solve the problem of intensity inhomogeneity in images. In addition, by introducing this feature into the fitting process, the model exhibits greater accuracy when compared to existing models. Experimental results from synthetic images and coronary X‐ray angiograms verify the desirable performance of the proposed model.
Precursory signatures of protein folding/unfolding: From time series correlation analysis to atomistic mechanisms
Authors: Hsu P. J. , Cheong S. A. , Lai S. K.
Published: May 2014

Folded conformations of proteins in thermodynamically stable states have long lifetimes. Before it folds into a stable conformation, or after unfolding from a stable conformation, the protein will generally stray from one random conformation to another leading thus to rapid fluctuations. Brief structural changes therefore occur before folding and unfolding events. These short-lived movements are easily overlooked in studies of folding/unfolding for they represent momentary excursions of the protein to explore conformations in the neighborhood of the stable conformation. The present study looks for precursory signatures of protein folding/unfolding within these rapid fluctuations through a combination of three techniques: (1) ultrafast shape recognition, (2) time series segmentation, and (3) time series correlation analysis. The first procedure measures the differences between statistical distance distributions of atoms in different conformations by calculating shape similarity indices from molecular dynamics simulation trajectories. The second procedure is used to discover the times at which the protein makes transitions from one conformation to another. Finally, we employ the third technique to exploit spatial fingerprints of the stable conformations; this procedure is to map out the sequences of changes preceding the actual folding and unfolding events, since strongly correlated atoms in different conformations are different due to bond and steric constraints. The aforementioned high-frequency fluctuations are therefore characterized by distinct correlational and structural changes that are associated with rate-limiting precursors that translate into brief segments. Guided by these technical procedures, we choose a model system, a fragment of the protein transthyretin, for identifying in this system not only the precursory signatures of transitions associated with α helix and β hairpin, but also the important role played by weaker correlations in such protein folding dynamics.
Distinguishability and chiral stability in solution: Effects of decoherence and intermolecular interactions
Authors: Han Heekyung , Wardlaw David M. , Frolov Alexei M.
Published: May 2014

We examine the effect of decoherence and intermolecular interactions (chiral discrimination energies) on the chiral stability and the distinguishability of initially pure versus mixed states in an open chiral system. Under a two-level approximation for a system, intermolecular interactions are introduced by a mean-field theory, and interaction between a system and an environment is modeled by a continuous measurement of a population difference between the two chiral states. The resultant equations are explored for various parameters, with emphasis on the combined effects of the initial condition of the system, the chiral discrimination energies, and the decoherence in determining: the distinguishability as measured by a population difference between the initially pure and mixed states, and the decoherence process; the chiral stability as measured by the purity decay; and the stationary state of the system at times long relative to the time scales of the system dynamics and of the environmental effects.
Omnidirectional acoustic absorber with a porous core and a metamaterial matching layer
Authors: Elliott A. S. , Venegas R. , Groby J. P. , Umnova O.
Published: May 2014

An omnidirectional sound absorber based on the acoustic analogy of the electromagnetic metamaterial “black hole” has been developed and tested. The resulting structure is composed of a hollow cylindrical porous absorbing core and a graded index matching layer which employs multiple rods of varying size and spacing to gradually adjust the impedance of the air to that of the porous absorbing core. A semi-analytical model is developed, and the practical challenges and their implications with respect to performance are considered. A full size device is built and tested in an anechoic chamber and the semi-analytical model used in the design process is validated. Finally, the theory is extended to allow for losses in the metamaterial matching layer, and it is shown that improved performance may be achieved with a dual purpose layer which acts as an absorber whilst also providing the required impedance matching condition.
The understanding of the drain-current fluctuation in a silicon-carbon source-drain strained n-channel metal-oxide-semiconductor field-effect transistors
Authors: Hsieh E. R. , Chung Steve S.
Published: May 2014

In a certain class of strained n-channel metal-oxide-semiconductor field effect transistor (MOSFET) with silicon-carbon (Si:C) as a stressor in its source/drain, it serves as good candidate for high mobility and drain current device. However, its drain current (Id) fluctuation and the threshold voltage (Vth) fluctuation, have not been clarified. This paper reports a systematic method to analyze the sources of the above two different fluctuations represented by σId and σVth, respectively. The dominant sources of the σId and σVth have been clarified on experimental n-channel Si:C source/drain FETs. The Id fluctuation relies on the dopant fluctuation or the mobility factors related to the conductions at various biases. Results show that the Id fluctuation at low field or low gate bias, i.e., near the threshold, is dominated by the RDF (Random Dopant Fluctuation) effect, while at high field, it is dominated by the channel conduction and scattering events which can be adequately described by the changes of mobility. The abnormal increase in the RDF effect in the Si:C was induced by the carbon out-diffusion from the drain into the channel. A dopant profiling technique has been developed to validate the out-diffusion effect.
Prevention of early‐onset Group B Streptococcal disease – the Northern Ireland experience
Authors: Eastwood KA , Craig S , Sidhu H , Boyle M , Gannon C , Ong G , Lupari M , Craven A , Magowan S , Ashe RG
Published: May 2014

Objectives

To ascertain guideline adherence for prevention of Group B Streptococcal (GBS) neonatal infection and establish prevalence and outcomes in Northern Ireland (NI).

Design

Retrospective observational study.

Setting

Northern Ireland maternity units.

Population

Using NI Health Information Systems the following were identified: (1) a cohort of women with one or more risk factors for GBS disease in 2009–2010, (2) all culture‐positive cases of GBS in babies aged 0–89 days (2008–2010), (3) stillbirths due to GBS (2009–2010).

Methods

Information was analysed for a 15% randomised sample of the available cases. Maternal and infant case notes were reviewed for confirmed cases of neonatal early onset GBS (EOGBS) during 2008–2010.

Main outcome measures

Adherence to the 2003 RCOG guideline on prevention of GBS disease (2009–2010). Number of neonatal GBS infections: antenatal risk factors, management and neonatal outcomes (2008–2010). The number of stillbirths related to GBS (2009–2010).

Results

Five hundred and seventy‐four women had one or more identifiable risk factors for GBS disease; intrapartum antibiotic prophylaxis (IAP) was administered in 42% of cases. Improved administration of IAP was noted in the presence of escalating risk factors. At best, guideline adherence was 50–70%. Forty‐three neonates had proven early‐onset Group B Streptococcal disease; 55.8% had maternal risk factors. Of the total identified cases, 25.5% received IAP. The total mortality rate was 11.46%. The incidence of EOGBS disease in NI was 0.57/1000 live births.

Conclusions

Prevalence of EOGBS is higher in NI than the UK as a whole. Risk factors are present in 55.8% of mothers; IAP does not prevent all cases of EOGBS.
The extensible integument of Rhipicephalus sanguineus female ticks in different feeding stages: a morphological approach
Authors: Remedio Rafael N. , Nunes Pablo H. , Camargo‐Mathias Maria I.
Published: May 2014

Ticks are among the most important pathogen vectors worldwide, and the knowledge of their internal and external morphology may provide relevant information that will allow an adequate control of these animals. In this sense, the integument gains prominence, not only because of its wide capacity of expansion, but also due to the fact that this region is usually the first site of contact with natural and synthetic acaricides. Therefore, this study aimed to describe the morphology of alloscutal integument of R. sanguineus female ticks in three different feeding stages by means of histological and ultramorphological analysis. Significant differences were observed in all stages, with respect to the size of cells and layers, and to cuticle unfolding throughout the feeding process. Cuticle is divided into two main layers, the epicuticle and the procuticle, and is separated from a unistratified epithelium by a subcuticular layer. Procuticle, in turn, is divided into two layers, the endocuticle and exocuticle. Unfed female ticks showed cuticle with numerous folds, which decrease in quantity as the feeding expansion of the whole animal occurs. Opening of dermal glands and presence of setae also differed among groups.
Role of constraint on the shift of ductile–brittle transition temperature of subsize Charpy specimens
Authors: Capelle J. , Ben Amara M. , Pluvinage G. , Azari Z.
Published: May 2014

The ductile–brittle transition temperature is not intrinsic to steel but depends on the specimen type and loading mode used for the test. The influence of these parameters is related to the plastic constraint. Here, the constraint is evaluated by the effective T‐stress obtained by the stress difference method on the notch tip stress distribution. From Charpy energy values at different temperatures, it is possible to obtain a material failure master curve where the notch fracture toughness is plotted versus the shift of test temperature with the transition temperature corresponding to the effective T‐stress value. Values of the critical effective T‐stress are obtained for three subsize Charpy specimens (3/4, 1/2 and 1/3) and are reported on a material transition temperature master curve versus effective T‐stress. This allows obtaining the shift of transition temperature when comparing with those of a standard Charpy V specimen. The results do not confirm the prediction given by the empirical relation of the ASME.
Management and decision‐making process leading to coronary angiography and revascularization in octogenarians with coronary artery disease: Insights from a large single‐center registry
Authors: Martin Anne‐Céline , Dumas Florence , Spaulding Christian , Manzo‐Silberman Stéphane
Published: May 2014

Aims

Cardiovascular diseases remain the most common cause of death in older adults. Guidelines state that advanced age alone should not limit the use of invasive therapy. However, coronary angiograms and subsequent revascularization are often not carried out in octogenarians. The benefit/risk balance of an invasive strategy and the decision‐making process are not clearly defined. The aim of the present study was to assess the decision‐making process, and the in‐hospital and long‐term mortality based on the clinical presentation, the diagnostic approach (coronary angiogram or conservative) and the therapeutic management (revascularization or not).

Methods

The present study was a single‐center retrospective analysis.

Results

A total of 522 patients aged ≥80 years, with a diagnosis of coronary disease were included from 2003 to 2009. The mean age was 82 ± 2.6 years. A total of 195 of 522 (37%) presented with a ST segment elevation myocardial infarction (STEMI). A coronary angiogram was carried out in 316 patients (60.5%) and 71% were treated by percutaneous coronary revascularization. A total of 39.5% were considered ineligible for a coronary angiogram due to cardiological reasons or comorbidities. Excluding cardiogenic shock, overall in‐hospital mortality was 4.9%. Clinical presentation strongly influenced both in‐hospital and 6‐month mortality rates (cardiogenic shock 20% and 28.7%, stable angina 1% and 4.1%, respectively, P < 0.001). Long‐term mortality was reduced in the coronary angiography arm compared with the conservative group (14.3% vs 20.9%, P = 0.04) whether or not revascularization was carried out.

Conclusion

In the present study, in octogenarians, long‐term mortality was lower in the group of patients who underwent a coronary angiogram, regardless of revascularization. The selection process for coronary angiography and angioplasty was mostly influenced by the existence of age‐associated comorbidities. Risk prediction models are required to reduce age‐dependent biases. Geriatr Gerontol Int 2015; 15: 544–552.
Direct Delivery of Inoculum to Shoot Tissue Interferes with Genotypic Resistance to Ralstonia solanacearum in Tomato Seedlings
Authors: Thomas Pious , Sadashiva Avverahally T. , Upreti Reshmi , Mujawar Mohammed M.
Published: May 2014

Employing known susceptible and resistant genotypes and pure bacterial inoculum (0.1 OD; 108 CFU/ml−1), five different inoculation methods were tried to assess the response of tomato genotypes to Ralstonia solanacearum. This included seed‐soaking inoculation, seed‐sowing followed by inoculum drenching, or at 2‐week stage through petiole‐excision inoculation, soaking of planting medium with inoculum either directly or after imparting seedling root‐injury. Seed‐based inoculations or mere inoculum drenching at 2 weeks did not induce much disease in seedlings. Petiole inoculation induced 90–100% mortality in susceptible checks but also 50–60% mortality in normally resistant genotypes within 7–10 days. Root‐injury inoculation at 2‐week seedling stage appeared the best for early and clearer distinction between resistant and susceptible lines. The observations suggest a role played by the root system in governing genotypic resistance to the pathogen. Direct shoot inoculation is to be adopted only for selecting highly resistant lines or to thin down segregating populations during resistance breeding.
Phylogenetic and cytogenetic studies reveal hybrid speciation inSaxifragasubsect.Triplinervium(Saxifragaceae)
Authors: MAS DE XAXARS Gemma , GARCÍA‐FERNÁNDEZ Alfredo , BARNOLA Pere , MARTÍN Joan , MERCADÉ Arnau , VALLÈS Joan , VARGAS Pablo , VIGO Josep , GARNATJE Teresa
Published: May 2014

Hybridization has played an important role inSaxifragaevolution causing reticulation and a high number of described hybrids, but little is known about how hybrid speciation had occurred in the genus. We focus on a group of closely relatedSaxifragaspecies of the subsectionTriplinerviumfrom Pyrenees, the phylogenetic relationships of which remain unsolved. Trying to unmask cryptic (or ancient) hybridization processes, we analyze one nuclear (ITS) and three plastid regions (rpl32‐trnL,trnS‐trnG‐trnG, and3′trnV‐ndhC), as well as nuclear DNA content. Pollen and seed morphology and viability studies were carried out to evaluate the status of spontaneous hybrids. DNA ploidy levels were also inferred for the two Madeiran taxa (of the sameSaxifragasubsection), where recent hybridization processes are not expected. Molecular markers revealed multiple reticulation events, which, as suggested by DNA content and chromosome numbers, have occurred in homoploidy (without genome doubling after hybridization). In addition, autopolyploidy has occurred in some species or populations, especially in the Madeiran archipelago colonization. Chromosome number variation appears to be related to centric fission events, which also could lead to the formation of the B chromosomes inferred in some taxa. Spontaneous hybrids do not produce viable seeds and this could be due to differences in parental chromosome numbers. Hybrid speciation has probably been successful by chromosomal arrangements, which also generated new, more or less intermediate, chromosomal numbers in this group of taxa.
Psychosis after vagus nerve stimulation therapy
Authors: Chen Wei‐Ling , Lin Chin‐Chien , Chan Chin‐Hong
Published: May 2014

A 24‐year‐old man developed psychosis after improvement of epilepsy with vagus nerve stimulation treatment. He had a similar response when seizures were controlled by anticonvulsion agents. Psychosis was relieved with withdrawal of antiseizure treatment, but seizures then recurred.
Major histocompatibility complex class II alleles and haplotypes associated with non‐suppurative meningoencephalitis in greyhounds
Authors: Shiel R. E. , Kennedy L. J. , Nolan C. M. , Mooney C. T. , Callanan J. J.
Published: May 2014

Non‐suppurative meningoencephalitis is a breed‐restricted canine neuroinflammatory disorder affecting young greyhounds in Ireland. A genetic risk factor is suspected because of the development of disease in multiple siblings and an inability to identify a causative infectious agent. The aim of this study was to examine potential associations between dog leucocyte antigen (DLA) class II haplotype and the presence of the disease. DLA three locus haplotypes were determined in 31 dogs with non‐suppurative meningoencephalitis and in 115 healthy control dogs using sequence‐based typing (SBT) methods. All dogs were unrelated at the parental level. Two haplotypes (DRB1*01802/DQA1*00101/DQB1*00802 and DRB1*01501/DQA1*00601/DQB1*02201) were significantly (P = 0.0099 and 0.037) associated with the presence of meningoencephalitis, with odds ratios (95% confidence interval) of 5.531 (1.168–26.19) and 3.736 (1.446–9.652), respectively. These results confirm that there is an association between DLA class II haplotype and greyhound meningoencephalitis, suggesting an immunogenetic risk factor for the development of the disease. Greyhound meningoencephalitis may be a suitable model for human neuroinflammatory diseases with an immunogenetic component.
Solar-Assisted Heat Pump Systems: A Review of Existing Studies and Their Applicability to the Canadian Residential Sector
Authors: Chu Jenny , Cruickshank Cynthia A.
Published: May 2014

Combining solar thermal collectors and heat pumps into a single solar-assisted heat pump (SAHP) system is a promising technology for offsetting domestic hot water (DHW), space-heating, and cooling loads more efficiently. Task 44 of the Solar Heating and Cooling (SHC) Programme of the International Energy Agency (IEA) is currently investigating ways to optimize solar and heat pump systems for residential use. This paper presents a review of past and current work conducted on SAHP systems. Specifically, the key performance data from many studies are highlighted and different system configurations are compared in order to establish insight toward which system configurations are suitable for the Canadian residential sector. It was found that the most suitable configuration for Canadian residential buildings depends on a combination of factors which include occupant behavior, building characteristics, operation parameters, system components, and climate. A large variety of configurations and parameters exist and this made analyzing a specific system, comparing differing systems and establishing an optimal design difficult. It was found that different authors used different performance criterion and this inconsistency also added to the difficulty of comparing the studies of different systems.
Probing the Effect of Random Adhesion Energy on Receptor-Mediated Endocytosis With a Semistochastic Model
Authors: Chen Bin
Published: May 2014

The cellular uptake of a particle through receptor-mediated endocytosis involves specific binding between ligands on the particle surface and diffusive receptors on the cell membrane. Since the rupture force of these specific bonds is generally random, the same can be the associated adhesion energy. To probe the effect of this randomness, we present a semistochastic model of receptor-mediated endocytosis, in which the adhesion energy between particle and membrane is regarded as a stochastic parameter obeying Boltzmann's distribution. It is shown that the so-called speed factor varies and that the rate of uptake is much lower than that from a previous deterministic model. It is also found that a spontaneous curvature can significantly increase the rate of uptake for particles of certain sizes. When constraining the random adhesion energy, we find that the rate of uptake can substantially increase. This work suggests that adhesion energy may be actively regulated during receptor-mediated endocytosis to improve the efficiency. By adopting random adhesion energy in the analysis, the physical picture of endocytosis implicated by the current work can be fundamentally different from that by a previous deterministic model.
Stop codon reassignments in the wild
Authors: Ivanova Natalia N. , Schwientek Patrick , Tripp H. James , Rinke Christian , Pati Amrita , Huntemann Marcel , Visel Axel , Woyke Tanja , Kyrpides Nikos C. , Rubin Edward M.
Published: May 2014

The canonical genetic code is assumed to be deeply conserved across all domains of life with very few exceptions. By scanning 5.6 trillion base pairs of metagenomic data for stop codon reassignment events, we detected recoding in a substantial fraction of the >1700 environmental samples examined. We observed extensive
opal
and
amber
stop codon reassignments in bacteriophages and of
opal
in bacteria. Our data indicate that bacteriophages can infect hosts with a different genetic code and demonstrate phage-host antagonism based on code differences. The abundance and diversity of genetic codes present in environmental organisms should be considered in the design of engineered organisms with altered genetic codes in order to preclude the exchange of genetic information with naturally occurring species.
Antibodies to PfSEA-1 block parasite egress from RBCs and protect against malaria infection
Authors: Raj Dipak K. , Nixon Christian P. , Nixon Christina E. , Dvorin Jeffrey D. , DiPetrillo Christen G. , Pond-Tor Sunthorn , Wu Hai-Wei , Jolly Grant , Pischel Lauren , Lu Ailin , Michelow Ian C. , Cheng Ling , Conteh Solomon , McDonald Emily A. , Absalon Sabrina , Holte Sarah E. , Friedman Jennifer F. , Fried Michal , Duffy Patrick E. , Kurtis Jonathan D.
Published: May 2014

Novel vaccines are urgently needed to reduce the burden of severe malaria. Using a differential whole-proteome screening method, we identified
Plasmodium falciparum
schizont egress antigen-1 (PfSEA-1), a 244-kilodalton parasite antigen expressed in schizont-infected red blood cells (RBCs). Antibodies to PfSEA-1 decreased parasite replication by arresting schizont rupture, and conditional disruption of PfSEA-1 resulted in a profound parasite replication defect. Vaccination of mice with recombinant
Plasmodium berghei
PbSEA-1 significantly reduced parasitemia and delayed mortality after lethal challenge with the
Plasmodium berghei
strain ANKA. Tanzanian children with antibodies to recombinant PfSEA-1A (rPfSEA-1A) did not experience severe malaria, and Kenyan adolescents and adults with antibodies to rPfSEA-1A had significantly lower parasite densities than individuals without these antibodies. By blocking schizont egress, PfSEA-1 may synergize with other vaccines targeting hepatocyte and RBC invasion.
A new look
Authors: McNutt Marcia
Published: May 2014

With this issue, you will note a new look of
Science
, in both print and online, to make the journal clearer, easier to navigate, and more inviting to the reader. Change can elicit strong reactions, and for that reason I would like to walk you through some of the changes and their rationale.
Doing the math in Berlin
Authors: Kupferschmidt Kai , Vogel Gretchen
Published: May 2014

To keep Germany's science from stalling, research minister Johanna Wanka must break a federal-state impasse
Tracking who climbs up—and who falls down—the ladder
Authors: Mervis Jeffrey
Published: May 2014

Researchers seek new ways to understand social mobility and opportunity in America
Draft Genome Sequence of Actibacterium mucosum KCTC 23349, a Marine Alphaproteobacterium with Complex Ionic Requirements Isolated from Mediterranean Seawater at Malvarrosa Beach, Valencia, Spain
Authors: Arahal David R. , Shao Zongze , Lai Qiliang , Pujalte María J.
Published: May 2014

Strain R46 (CECT 7668; KCTC 23349), a nomenclatural type of
Actibacterium mucosum
, was isolated from surface seawater collected at Malvarrosa Beach (Valencia, Spain) in July 2008. The draft genome sequence of strain R46 (approximately 3.72 Mbp) contains 22 scaffolds and 3,619 protein-encoding genes, with a G+C content of 60.8 mol%.
An unusual presentation of bilateral Hutch diverticula
Authors: Fanning Deirdre Mary , Morrin Martina , Power Richard
Published: May 2014

Hutch diverticula are rare congenital diverticula. The general consensus is that they occur secondary to a congenital failure of normal muscle development around the ureteral orifice where Waldeyer sheath anatomically covers the space between the intravesical ureter and muscular layer of the bladder. Our case highlights the radiological appearance of Hutch diverticula and the need for contrast-enhanced imaging to enable accurate evaluation and diagnosis. It illustrates how the presence of periureteric diverticula can contribute to ureteric obstruction and calculus formation; complicate the interpretation of renal tract imaging and the subsequent management of renal calculi.
Simultaneous shoulder and elbow dislocation
Authors: Çobanoğlu Mutlu , Yumrukcal Feridun , Karataş Cengiz , Duygun Fatih
Published: May 2014

Ipsilateral shoulder and elbow dislocation is very rare and only six articles are present in the literature mentioning this kind of a complex injury. With this presentation we aim to emphasise the importance of assessing the adjacent joints in patients with trauma in order not to miss any accompanying pathologies. We report a case of a 43-year-old female patient with ipsilateral right shoulder and elbow dislocation treated conservatively. The patient reported elbow pain when first admitted to emergency service but she was diagnosed with simultaneous ipsilateral shoulder and elbow injury and treated conservatively. As a more painful pathology may mask the additional ones, one should hasten to help before performing a complete evaluation. Any harm caused to the patient due to this reason would not be a complication but a malpractice.
Exploring relationship between human mobility and social ties: Physical distance is not dead
Authors: Jin Bo , Liao Binbing , Yuan Ning , Wang Wenjun
Published: May 2014

Partly due to the difficulty of the access to a worldwide dataset that simultaneously captures the location history and social networks, our understanding of the relationship between human mobility and the social ties has been limited. However, this topic is essential for a deeper study from human dynamics and social networks aspects. In this paper, we examine the location history data and social networks data of 712 email users and 399 offline events users from a map-editing based social network website. Based on these data, we expand all our experiment both from individual aspect and community aspect. We find that the physical distance is still the most influential factor to social ties among the nine representative human mobility features extracted from our GPS trajectory dataset, although Internet revolution has made long-distance communication dramatically faster, easier and cheaper than ever before, and in turn, partly expand the physical scope of social networks. Furthermore, we find that to a certain extent, the proximity of South–North direction is more influential than East–West direction to social ties. To the our best of our knowledge, this difference between South–North and East–West is the first time to be raised and quantitatively supported by a large dataset. We believe our findings on the interplay of human mobility and social ties offer a new perspective to this field of study.
MODULATION OF PTCDA NANOSTRUCTURE AND OPTICAL PROPERTY: DEPENDENCE ON GROWTH TEMPERATURE
Authors: GUO PANPAN , HAN YUYAN , ZHANG WENHUA , LIU LINGYUN , WANG KAI , XU FAQIANG
Published: May 2014

3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) nanostructures with different morphologies are prepared on glass substrates at different substrate temperature (Ts) in a molecular beam epitaxy (MBE) system. Scanning/transmission/scanning transmission electron microscopy (SEM/TEM/STEM), X-ray diffraction (XRD), selected area electron diffraction (SAED) and nanobeam diffraction (NBD) techniques are employed in the systematical characterizations of the nanostructures. It is found that the PTCDA nanosheets (NSs), nanowires and nanorods are facile to produce at Ts = 350° C , 330°C and 240°C, respectively; the continuous films are obtained at 180°C and 50°C. XRD studies indicate that only the α-phase polymorph is formed regardless of the Ts. SAED and NBD results show that the nanowire and NS are single crystalline. The optical properties of the prepared PTCDA nanostructures are also found to be influenced by Ts and are correlated with the crystal quality and size. PTCDA nanowires and NSs exhibit an obvious redshift and broadening in the adsorption spectra, and enhanced emission intensity. The improved optical properties facilitate potential applications of these nanostructures in organic optoelectronic devices.
MicroRNA-23b Regulates Cyclin-Dependent Kinase–Activating Kinase Complex Through Cyclin H Repression to Modulate Endothelial Transcription and Growth Under Flow
Authors: Wang Kuei-Chun , Nguyen Phu , Weiss Anna , Yeh Yi-Ting , Chien Hou Su , Lee Alicia , Teng Dayu , Subramaniam Shankar , Li Yi-Shuan , Chien Shu
Published: May 2014

Objective—

The site-specificity of endothelial phenotype is attributable to the local hemodynamic forces. The flow regulation of microRNAs in endothelial cells (ECs) plays a significant role in vascular homeostasis and diseases. The objective of this study was to elucidate the molecular mechanism by which the pulsatile shear flow–induced microRNA-23b (miR-23b) exerts antiproliferative effects on ECs.

Approach and Results—

We used a combination of a cell perfusion system and experimental animals to examine the flow regulation of miR-23b in modulating EC proliferation. Our results demonstrated that pulsatile shear flow induces the transcription factor Krüppel-like factor 2 to promote miR-23b biosynthesis; the increase in miR-23b then represses cyclin H to impair the activity and integrity of cyclin-dependent kinase–activating kinase (CAK) complex. The inhibitory effect of miR-23b on CAK exerts dual actions to suppress cell cycle progression, and reduce basal transcription by deactivating RNA polymerase II. Whereas pulsatile shear flow regulates the miR-23b/CAK pathway to exert antiproliferative effects on ECs, oscillatory shear flow has little effect on the miR-23b/CAK pathway and hence does not cause EC growth arrest. Such flow pattern–dependent phenomena are validated with an in vivo model on rat carotid artery: the flow disturbance induced by partial carotid ligation led to a lower expression of miR-23b and a higher EC proliferation in comparison with the pulsatile flow regions of the unligated vessels. Local delivery of miR-23b mitigated the proliferative EC phenotype in partially ligated vessels.

Conclusions—

Our findings unveil a novel mechanism by which hemodynamic forces modulate EC proliferative phenotype through the miR-23b/CAK pathway.
Diversity in Marketing System Assortments
Authors: Layton Roger A. , Duan Zhirong
Published: May 2014

An assortment offered by a marketing system can be defined as a set of separable or distinguishable products, services, experiences and ideas, or aggregates thereof, assembled in response to or anticipation of customer demand. As marketing systems form and grow, assortment diversity often increases, raising concerns about excessive or inadequate customer choice. Changing assortment diversity may also point to deeper issues of emerging dominance and inequality, to concerns about marketing system resilience in the face of environmental turbulence, and to issues of access to vulnerable segments. After highlighting the contribution of Alderson in emphasising diversity in buyer and seller heterogeneity, we note the differences between offered, accessible, desired, acquired and accumulated assortments, and the difficulties in establishing categories or types in the measurement of assortment. Variety, disparity, balance, and association are identified as providing measures of assortment diversity. We then considers the ways in which such measures may be pointers to underlying marketing system characteristics, including the offer of too much or too little choice, problems of stability in the face of external or internal change, system resilience or capacity to adapt to change, and issues around assortment and quality of life. We conclude with suggestions as to further research into assortment diversity and marketing system characteristics.
Radiation dose and image quality with abdominal computed tomography with automated dose-optimized tube voltage selection
Authors: Hu Lirong , Wang Yujun , Hou Hongtao , Wei Fuquan , Yang Guangzhao , Chen Yougeng
Published: May 2014

Objectives

This study assessed image quality and radiation dose of multidetector computed tomography (CT) examination using a standard protocol and a low-voltage protocol.

Methods

Patients requiring contrast-enhanced abdominal CT examination were randomly assigned to two groups with different voltage protocols: (i) 120 kV; (ii) an automated attenuation-based tube potential optimization mode (CARE kV). The volume CT dose index (CTDIvol) and dose length product (DLP) were recorded. Image quality was semiquantitatively assessed by two blinded radiologists using a five-point scale.

Results

There were 39 patients in the 120 kV group and 50 patients in the CARE kV group. There was no obvious difference in image quality score between the groups. CARE kV resulted in a voltage reduction to 100 kV in 45 patients and to 80 kV in five patients. CTDIvol and DLP were significantly lower with CARE kV than with the 120 kV protocol.

Conclusions

The use of CARE kV reduces radiation dose with no loss of image quality compared with a standard 120 kV protocol.
What drives ethnic terrorist campaigns? A view at the group level of analysis
Authors: Boylan Brandon M.
Published: May 2014

This article examines the drivers of terrorist campaigns waged specifically for the sake of ethnic identity groups. Terrorism scholarship has generally overlooked the ethnic dimension that some terrorist campaigns have in favor of building or testing theories applicable to all terrorist violence, regardless of ideological orientation. The research that does address ethnic terrorism attributes it either to a broad and vague notion of nationalism or to factors that might be idiosyncratic of a small number of cases. This study tests the causes of ethnic terrorism found to be of most theoretical salience: political and economic grievances with the host state and competition between the ethnic community’s elites for control over the group. It uses data at the ethnic group level of analysis, rather than the more common country level. In doing so, model results should offer improved explanations for the outcome of ethnic terrorism, linking group features, rather than country characteristics or subnational factors aggregated to the country level, directly to group terrorism. The results show that political grievances and elite competition increase the likelihood of ethnic terrorism, while economic grievances are not generally associated with this form of violence.
Examining Readers’ Evaluations of Objectivity and Bias in News Discourse
Authors: Cramer Peter , Eisenhart Christopher
Published: May 2014

Readers’ objectivity and bias evaluations of news texts were investigated in order to better understand the process by which readers make these kinds of judgments and the evidence on which they base them. Readers were primed to evaluate news texts for objectivity and bias, and their selections and metacommentary were analyzed. Readers detected bias in passages with stance markers, and detected objectivity in those lacking stance markers. In their metacommentary, readers tended to characterize objective texts as lacking purpose, or having a merely descriptive or expository purpose, and biased texts as exhibiting explicit interpretive or argumentative purposes. Unlike studies that locate objectivity or bias in news texts, or test it by asking about the fidelity of texts to their sources, our study examined the evaluations of readers in their interactions with texts. It shows how objectivity and bias evaluations are a multiply determined part of a communication dynamic rather than a fixed quality of a text.
Modulating the release of drugs from alginate matrices with the addition of gelatin microbeads
Authors: Qian Qiang , Bonani Walter , Maniglio Devid , Chen Jie , Migliaresi Claudio
Published: May 2014

Injectable drug-loaded matrices and controlled release technology offer numerous advantages over conventional dosages. Cross-linkable alginate hydrogels have been proposed for in vivo injection, but their large initial burst release of encapsulated drugs represents a limitation for the transition to the clinical phase. To reduce this effect, a new drug delivery system was prepared by combining uncross-linked, drug-loaded gelatin microbeads with cross-linkable alginate solution. Gelatin microbeads ranging from 5 to 50 µm were obtained depending on gelatin concentration, stirring rate, and emulsifying time. The release behavior of drug-loaded gelatin microbeads encapsulated within cross-linked alginate gel was characterized both at room temperature and 37°C and compared with the release from gelatin microbeads and cross-linked alginate gel alone. Gelatin microbeads reduced the initial burst release of fluorescein from cross-linked alginate matrix, with a corresponding decrease in the release efficiency. Burst release in the first 2 h was reduced from 30% to about 5%, while cumulative release at 37°C declined from about 95% to 50% after 7 days. This system represents a promising approach for the development of novel and versatile injectable drug delivery systems.
In vitro evaluation of effects of sustained anti-TNF release from MPEG-PCL-MPEG and PCL microspheres on human rheumatoid arthritis synoviocytes
Authors: Erdemli Özge , Özen Seza , Keskin Dilek , Usanmaz Ali , Batu Ezgi Deniz , Atilla Bülent , Tezcaner Ayşen
Published: May 2014

Anti-tumor necrosis factor α (TNFα) drugs such as etanercept (ETN) have been mostly used in systemic treatment of rheumatoid arthritis. To eliminate the side effects in long-term treatments and to achieve a local sustained anti-inflammatory effect, a controlled drug delivery system is needed for anti-TNFα drugs. This study aims to develop novel injectable microcarriers of ETN that can provide long-term controlled release of this protein drug upon intra-articular application. In this study, poly(ε-caprolactone) (PCL) and its copolymer with poly(ethylene glycol), methoxypoly(ethylene glycol)-poly(ε-caprolactone)-methoxypoly(ethylene glycol) microspheres (MPEG-PCL-MPEG) were compared for their prospective success in rheumatoid arthritis treatment. Microspheres with smooth surface of a mean particle diameter of approximately 5 μm were prepared with both polymers. MPEG-PCL-MPEG microspheres had higher encapsulation efficiency than PCL microspheres. The activity of encapsulated ETN within MPEG-PCL-MPEG microspheres also retained while 90% of the activity of ETN within PCL microspheres could retain during 90-day release. MPEG-PCL-MPEG microspheres showed faster ETN release compared to PCL microspheres in various release media. Cumulative amounts of ETN released from both types of microspheres were significantly lower in cell culture medium and in synovial fluids than in phosphate buffered saline. This was mainly due to protein adsorption onto microspheres. Hydrophilic MPEG segment enhanced ETN release while preventing protein adsorption on microspheres compared to PCL. Sustained ETN release from microspheres resulted with a significant decrease in pro-inflammatory cytokines (TNFα, IFNγ, IL-6, IL-17) and MMP levels (MMP-3, MMP-13), while conserving viability of fibroblast-like synoviocytes compared to the free drug. Results suggest that MPEG-PCL-MPEG is a potential copolymer of PCL that can be used in development of biomedical materials for effective local treatment purposes in chronic inflammatory arthritis owing to enhanced hydrophilicity. Yet, PCL microspheres are also promising systems having good compatibility to synoviocytes and would be especially the choice for treatment approach requiring longer term and slower release.
Dynamic analysis of wind turbine drive train subjected to nonstationary wind load excitation
Authors: Srikanth P , Sekhar AS
Published: May 2014

The dynamic analysis of wind turbine drive train is presented in this paper. A typical wind turbine drive train consists of a rotor, gearbox and generator. The dynamic modelling of epicyclic gearbox that exists in wind turbine is challenging due to the fact that it has both rotating and orbiting gears. The dynamic equations of motion are obtained based on the rigid multibody modelling with discrete flexibility approach by Lagrange’s formulation. The dynamic model accounts for the time varying gear tooth mesh stiffness, linear stiffness of bearings and torsional shaft stiffness. The aerodynamic torque that a wind turbine drive train subjected to, is modelled based on the simplified method for load calculation in wind turbine, Danish Standard DS472. The characteristic load value acting per unit length at the two-thirds length of the blade is used for calculating the total load of the torsional moment. The vibration signals that are obtained from wind turbine drive train are nonlinear and nonstationary in nature. This is due to the fact that the applied torque load on drive train is nonlinear and nonstationary in nature. The coupled dynamic model of 18 degrees of freedom is solved for responses in time and frequency domains for some nonstationary wind load realizations. The dynamic responses of the system, contact forces between gear tooth pairs in time and frequency domains are obtained numerically. The study envisages that this dynamic model of wind turbine drive train is very useful for subsequent studies on condition monitoring.
Social Ecology of Adherence to Hypertension Treatment in Latino Migrant and Seasonal Farmworkers
Authors: Hall Eleanor , Lee Shih-Yu , Clark Patricia C. , Perilla Julia
Published: May 2014

Purpose: This study explored Latino migrant/seasonal farmworkers’ (MSFWs’) adherence to hypertension treatment. Design: A cross-sectional correlational study was conducted. Method: Forty-five Latino MSFWs from two farmworker health clinics completed Spanish versions of the Morisky Medication Adherence Scale, the Blood Pressure Knowledge Scale and Blood Pressure Self-Care Scale, the Perceived Stress Scale, the Acculturation Rating Scale for Mexican Americans–II, the Short Assessment of Health Literacy for Spanish-Speaking Adults, health care access questions, and blood pressure measurements. Results: MSFWs had poor medication adherence (51%). Blood pressure knowledge, perceived stress, acculturation, health literacy, and health care access accounted for 49% of the variance in blood pressure self-care. Higher acculturation level and health literacy were associated with better blood pressure control ( p = .01). Discussion: MSFWs had poor medication adherence and blood pressure control. Blood pressure knowledge and acculturation played a role in blood pressure self-care. Implications: Culturally appropriate educational programs are needed to help MSFWs’ adherence to hypertension treatment.
Effects of sonication and ultraviolet-C treatment as a hurdle concept on quality attributes of Chokanan mango (Mangifera indica L.) juice
Authors: Santhirasegaram Vicknesha , Razali Zuliana , Somasundram Chandran
Published: May 2014

The growing demand for fresh-like food products has encouraged the development of hurdle technology of non-thermal processing. In this study, freshly squeezed Chokanan mango juice was treated by paired combinations of sonication (for 15 and 30 min at 25 ℃, 40 kHz frequency) and UV-C treatment (for 15 and 30 min at 25 ℃). Selected physicochemical properties, antioxidant activities, microbial inactivation and other quality parameters of combined treated juice were compared to conventional thermal treatment (at 90 ℃ for 60 s). After thermal and combined treatment, no significant changes occurred in physicochemical properties. A significant increase in extractability of carotenoids (15%), polyphenols (37%), flavonoids (35%) and enhancement in antioxidant capacity was observed after combined treatment. Thermal and combined treatment exhibited significant reduction in microbial load. Results obtained support the use of sonication and UV-C in a hurdle technology to improve the quality of Chokanan mango juice along with safety standards.
Further investigation of safety monitoring guidelines based on magnetic resonance imaging lesion activity in multiple sclerosis clinical trials
Authors: Dong Jing , Zhao Yinshan , Petkau A John , Li David KB , Riddehough Andrew , Traboulsee Anthony
Published: May 2014

We assess two modified guidelines for monitoring patient safety in multiple sclerosis (MS) trials. These guidelines flag patients with an increase in contrast enhancing lesion (CEL) count above a threshold over the CEL level 1–2 months earlier. We compare the new guidelines to the original guideline where the threshold is set according to the baseline by applying the guidelines to two previous studies. The odds ratios of a subsequent clinical relapse associated with meeting the CEL threshold based on the modified guidelines are similar to those based on the original guideline. There is a need for patient and cohort specific monitoring procedures.