bluuebunny/crossref_metadata_2025 huggingface dataset:
Compressed‐sensing‐based content‐driven hierarchical reconstruction: Theory and application to C‐arm cone‐beam tomography
Authors: Langet Hélène , Riddell Cyril , Reshef Aymeric , Trousset Yves , Tenenhaus Arthur , Lahalle Elisabeth , Fleury Gilles , Paragios Nikos
Published: August 2015

Purpose:

This paper addresses the reconstruction of x‐ray cone‐beam computed tomography (CBCT) for interventional C‐arm systems. Subsampling of CBCT is a significant issue with C‐arms due to their slow rotation and to the low frame rate of their flat panel x‐ray detectors. The aim of this work is to propose a novel method able to handle the subsampling artifacts generally observed with analytical reconstruction, through a content‐driven hierarchical reconstruction based on compressed sensing.

Methods:

The central idea is to proceed with a hierarchical method where the most salient features (high intensities or gradients) are reconstructed first to reduce the artifacts these features induce. These artifacts are addressed first because their presence contaminates less salient features. Several hierarchical schemes aiming at streak artifacts reduction are introduced for C‐arm CBCT: the empirical orthogonal matching pursuit approach with the ℓ0pseudonorm for reconstructing sparse vessels; a convex variant using homotopy with the ℓ1‐norm constraint of compressed sensing, for reconstructing sparse vessels over a nonsparse background; homotopy with total variation (TV); and a novel empirical extension to nonlinear diffusion (NLD). Such principles are implemented with penalized iterative filtered backprojection algorithms. For soft‐tissue imaging, the authors compare the use of TV and NLD filters as sparsity constraints, both optimized with the alternating direction method of multipliers, using a threshold for TV and a nonlinear weighting for NLD.

Results:

The authors show on simulated data that their approach provides fast convergence to good approximations of the solution of the TV‐constrained minimization problem introduced by the compressed sensing theory. Using C‐arm CBCT clinical data, the authors show that both TV and NLD can deliver improved image quality by reducing streaks.

Conclusions:

A flexible compressed‐sensing‐based algorithmic approach is proposed that is able to accommodate for a wide range of constraints. It is successfully applied to C‐arm CBCT images that may not be so well approximated by piecewise constant functions.
Report sets new goals for U.S. Antarctic Program
Authors: Gramling Carolyn
Published: August 2015

Committee pushes study of ice loss, genomics, and radiation from the beginning of the universe.
The littlest farmhands
Authors: de Vrieze Jop
Published: August 2015

Scientists are discovering thousands of microbes that help plants survive and thrive. Could these symbionts help farmers as well?
Mus81 and converging forks limit the mutagenicity of replication fork breakage
Authors: Mayle Ryan , Campbell Ian M. , Beck Christine R. , Yu Yang , Wilson Marenda , Shaw Chad A. , Bjergbaek Lotte , Lupski James R. , Ira Grzegorz
Published: August 2015

How to repair broken replication forks

Double-strand breaks in DNA are extremely dangerous to the integrity of our genomes. Most arise from problems encountered by replication forks during duplication of genomic DNA. Break-induced replication is known to use an error-prone DNA polymerase to repair such damage. Mayle
et al.
show that cells limit error-prone DNA synthesis by preventing the DNA polymerase from inadvertently switching to a related sequence with an incorrect template. The repair of the break is achieved by using a structure-specific nuclease to prevent formation of a long single-stranded region.

Science
, this issue p.
742
A warm and poorly ventilated deep Arctic Mediterranean during the last glacial period
Authors: Thornalley D. J. R. , Bauch H. A. , Gebbie G. , Guo W. , Ziegler M. , Bernasconi S. M. , Barker S. , Skinner L. C. , Yu J.
Published: August 2015

Slow circulation in the cold Arctic

The Arctic Ocean and Nordic Seas together supply dense, sinking water to the Atlantic Meridional Overturning Circulation (AMOC). The redistribution of heat by the AMOC, in turn, exerts a major influence on climate in the Northern Hemisphere. Thornalley
et al.
report that during the last glacial period, those regions were nearly stagnant and supplied almost none of the water that they presently contribute to the AMOC. This low rate of flow into the Atlantic was probably due to an absence of vigorous deep-water formation in the Arctic Mediterranean as a consequence of the extensive ice cover there at that time.

Science
, this issue p.
706
Marmoset kids actually listen
Authors: Margoliash Daniel , Tchernichovski Ofer
Published: August 2015

Humans and other vertebrates may share a developmental program for vocal learning

[Also see Report by

Takahashi
et al.

]
Ebola virus vaccines—preparing for the unexpected
Authors: Klenk Hans-Dieter , Becker Stephan
Published: August 2015

Many lives might have been saved if clinical studies of Ebola virus vaccines had been done earlier

[Also see Report by

Marzi
et al.

]
Correlates of Vaccine-Induced Protection against Mycobacterium tuberculosis Revealed in Comparative Analyses of Lymphocyte Populations
Authors: Kurtz Sherry L. , Elkins Karen L.
Published: August 2015

A critical hindrance to the development of a novel vaccine againstMycobacterium tuberculosisis a lack of understanding of protective correlates of immunity and of host factors involved in a successful adaptive immune response. Studies from our group and others have used a mouse-basedin vitromodel system to assess correlates of protection. Here, using this coculture system and a panel of whole-cell vaccines with varied efficacy, we developed a comprehensive approach to understand correlates of protection. We compared the gene and protein expression profiles of vaccine-generated immune peripheral blood lymphocytes (PBLs) to the profiles found in immune splenocytes. PBLs not only represent a clinically relevant cell population, but comparing the expression in these populations gave insight into compartmentally specific mechanisms of protection. Additionally, we performed a direct comparison of host responses induced when immune cells were cocultured with either the vaccine strainMycobacterium bovisBCG or virulentM. tuberculosis. These comparisons revealed host-specific and bacterium-specific factors involved in protection against virulentM. tuberculosis. Most significantly, we identified a set of 13 core molecules induced in the most protective vaccines under all of the conditions tested. Further validation of this panel of mediators as a predictor of vaccine efficacy will facilitate vaccine development, and determining how each promotes adaptive immunity will advance our understanding of antimycobacterial immune responses.
Capsule Switching and Antimicrobial Resistance Acquired during Repeated Streptococcus pneumoniae Pneumonia Episodes
Authors: Chang Bin , Nariai Akiyoshi , Sekizuka Tsuyoshi , Akeda Yukihiro , Kuroda Makoto , Oishi Kazunori , Ohnishi Makoto
Published: August 2015

Streptococcus pneumoniae
colonizes the nasopharyngeal mucus in healthy people and causes otitis media, pneumonia, bacteremia, and meningitis. In this study, we analyzed an
S. pneumoniae
strain that caused 7 repeated pneumonia episodes in an 80-month-old patient with cerebral palsy during a period of 25 months. A total of 10
S. pneumoniae
strains were obtained from sputum samples, and serotype 6B was isolated from samples from the first 5 episodes, whereas serotype 6A was isolated from samples from the last 2. Whole-genome sequencing showed clonality of the 10 isolates with 10 single nucleotide polymorphisms (SNPs) in the genomes. Among these SNPs, one single point mutation in the
wciP
gene was presumed to relate to the serotype switching from 6B to 6A, and the other mutations in
parC
and
gyrA
were related to fluoroquinolone resistance. These results suggested that an
S. pneumoniae
strain, which asymptomatically colonized the patient's nasopharynx or was horizontally transmitted from an asymptomatic carrier, caused the repeated pneumonia events. Phenotypic variations in the capsule type and antimicrobial susceptibility occurred during the carrier state. Hyporesponsiveness to serotypes 6B and 6A of
S. pneumoniae
was found even after vaccination with the 7-valent pneumococcal conjugate vaccine and the 23-valent pneumococcal polysaccharide vaccine. After an additional vaccination with the 13-valent pneumococcal conjugate vaccine, opsonic activities for both serotypes 6A and 6B significantly increased and are expected to prevent relapse by the same strain.
Commutability of the First World Health Organization International Standard for Human Cytomegalovirus
Authors: Hayden R. T. , Preiksaitis J. , Tong Y. , Pang X. , Sun Y. , Tang L. , Cook L. , Pounds S. , Fryer J. , Caliendo A. M.
Published: August 2015

Quantitative detection of cytomegalovirus (CMV) DNA has become a standard part of care for many groups of immunocompromised patients; recent development of the first WHO international standard for human CMV DNA has raised hopes of reducing interlaboratory variability of results. Commutability of reference material has been shown to be necessary if such material is to reduce variability among laboratories. Here we evaluated the commutability of the WHO standard using 10 different real-time quantitative CMV PCR assays run by eight different laboratories. Test panels, including aliquots of 50 patient samples (40 positive samples and 10 negative samples) and lyophilized CMV standard, were run, with each testing center using its own quantitative calibrators, reagents, and nucleic acid extraction methods. Commutability was assessed both on a pairwise basis and over the entire group of assays, using linear regression and correspondence analyses. Commutability of the WHO material differed among the tests that were evaluated, and these differences appeared to vary depending on the method of statistical analysis used and the cohort of assays included in the analysis. Depending on the methodology used, the WHO material showed poor or absent commutability with up to 50% of assays. Determination of commutability may require a multifaceted approach; the lack of commutability seen when using the WHO standard with several of the assays here suggests that further work is needed to bring us toward true consensus.
DDX60L Is an Interferon-Stimulated Gene Product Restricting Hepatitis C Virus Replication in Cell Culture
Authors: Grünvogel Oliver , Esser-Nobis Katharina , Reustle Anna , Schult Philipp , Müller Birthe , Metz Philippe , Trippler Martin , Windisch Marc P. , Frese Michael , Binder Marco , Fackler Oliver , Bartenschlager Ralf , Ruggieri Alessia , Lohmann Volker
Published: August 2015

All major types of interferon (IFN) efficiently inhibit hepatitis C virus (HCV) replication
in vitro
and
in vivo
. Remarkably, HCV replication is not sensitive to IFN-γ in the hepatoma cell line Huh6, despite an intact signaling pathway. We performed transcriptome analyses between Huh6 and Huh-7 cells to identify effector genes of the IFN-γ response and thereby identified the DExD/H box helicase DEAD box polypeptide 60-like (DDX60L) as a restriction factor of HCV replication. DDX60L and its homolog DEAD box polypeptide 60 (DDX60) were both induced upon viral infection and IFN treatment in primary human hepatocytes. However, exclusively DDX60L knockdown increased HCV replication in Huh-7 cells and rescued HCV replication from type II IFN as well as type I and III IFN treatment, suggesting that DDX60L is an important effector protein of the innate immune response against HCV. In contrast, we found no impact of DDX60L on replication of hepatitis A virus. DDX60L protein was detectable only upon strong ectopic overexpression, displayed a broad cytoplasmic distribution, but caused cytopathic effects under these conditions. DDX60L knockdown did not alter interferon-stimulated gene (ISG) induction after IFN treatment but inhibited HCV replication upon ectopic expression, suggesting that it is a direct effector of the innate immune response. It most likely inhibits viral RNA replication, since we found neither impact of DDX60L on translation or stability of HCV subgenomic replicons nor additional impact on assembly of infectious virus. Similar to DDX60, DDX60L had a moderate impact on RIG-I dependent activation of innate immunity, suggesting additional functions in the sensing of viral RNA.

IMPORTANCE
Interferons induce a plethora of interferon-stimulated genes (ISGs), which are our first line of defense against viral infections. In addition, IFNs have been used in antiviral therapy, in particular against the human pathogen hepatitis C virus (HCV); still, their mechanism of action is not well understood, since diverse, overlapping sets of antagonistic effector ISGs target viruses with different biologies. Our work identifies DDX60L as a novel factor that inhibits replication of HCV. DDX60L expression is regulated similarly to that of its homolog DDX60, but our data suggest that it has distinct functions, since we found no contribution of DDX60 in combatting HCV replication. The identification of novel components of the innate immune response contributes to a comprehensive understanding of the complex mechanisms governing antiviral defense.
Human Papillomavirus 18 Genetic Variation and Cervical Cancer Risk Worldwide
Authors: Chen Alyce A. , Gheit Tarik , Franceschi Silvia , Tommasino Massimo , Clifford Gary M.
Published: August 2015

Human papillomavirus 18 (HPV18) is the second most carcinogenic HPV type, after HPV16, and it accounts for approximately 12% of squamous cell carcinoma (SCC) as well as 37% of adenocarcinoma (ADC) of the cervix worldwide. We aimed to evaluate the worldwide diversity and carcinogenicity of HPV18 genetic variants by sequencing the entire long control region (LCR) and the E6 open reading frame of 711 HPV18-positive cervical samples from 39 countries, taking advantage of the International Agency for Research on Cancer biobank. A total of 209 unique HPV18 sequence variants were identified that formed three phylogenetic lineages (A, B, and C). A and B lineages each divided into four sublineages, including a newly identified candidate B4 sublineage. The distribution of lineages varied by geographical region, with B and C lineages found principally in Africa. HPV18 (sub)lineages were compared between 453 cancer cases and 236 controls, as well as between 81 ADC and 160 matched SCC cases. In region-stratified analyses, there were no significant differences in the distribution of HPV18 variant lineages between cervical cancer cases and controls or between ADC and SCC. In conclusion, our findings do not support the role of HPV18 (sub)lineages for discriminating cancer risk or explaining why HPV18 is more strongly linked with ADC than SCC.

IMPORTANCE
This is the largest and most geographically/ethnically diverse study of the genetic variation of HPV18 to date, providing a comprehensive reference for phylogenetic classification of HPV18 sublineages for epidemiological and biological studies.
Spontaneous regression of intracranial aneurysm following remote ruptured aneurysm treatment with pipeline stent assisted coiling
Authors: Tsimpas Asterios , Ashley William W , Germanwala Anand V
Published: August 2015

Spontaneous aneurysm regression is a rare phenomenon. We present the interesting case of a 54-year-old woman who was admitted with a Hunt/Hess grade IV, Fisher grade III subarachnoid hemorrhage and multiple intracranial aneurysms. She was treated with coiling of the largest paraclinoid aneurysm and placement of a flow diverting pipeline embolization device that covered all internal carotid artery (ICA) aneurysms. A follow-up angiogram at 6 months showed remodeling of the ICA with complete obliteration of all treated aneurysms. A distant, untreated, right frontal M2 aneurysm regressed spontaneously, after the flow was diverted away from it with the stent. The literature is reviewed, and potential pathophysiological mechanisms leading to aneurysm regression are discussed.
Milk-sensitive eosinophilic gastroenteritis in a 2-month-old boy
Authors: Costa Conceição , Pinto Pais Isabel , Rios Elisabete , Costa Cristina
Published: August 2015

Eosinophilic gastroenteritis is a rare disease of unknown aetiology, characterised by eosinophilic infiltration of the gastrointestinal wall with various gastrointestinal manifestations. Clinical presentation and radiological findings are non-specific and there is an overlap with more frequent childhood diseases requiring a high degree of clinical suspicion for accurate diagnosis. We describe a 2-month-old boy with prolonged diarrhoea, vomiting and food refusal. Diagnosis was settled by histology. The treatment with elemental diet was successful, with clinical resolution and catch-up growth.
Spontaneous coronary artery dissection: the management dilemma continues
Authors: Ahmed Zaheer , Bajwa Ata , Bhardwaj Bhaskar , Laster Steven B , Magalski Anthony
Published: August 2015

Spontaneous coronary artery dissection (SCAD) is an increasingly recognised cause of acute coronary syndrome, particularly in women. A 36-year-old Caucasian woman presented to our hospital with sudden onset chest pain and was diagnosed with a non-ST elevation myocardial infarction. Coronary angiography revealed mid and distal left anterior descending artery (LAD) dissection with distal LAD occlusion. A short segment of apical LAD filled late with incomplete opacification (Thrombolysis In Myocardial Infarction (TIMI) 1 flow). A decision was made to treat the patient conservatively, with subsequent resolution of dissection over the next 3 months. Our patient made a good clinical recovery with healing of her affected coronary vasculature on subsequent angiogram. The case illustrates that SCAD can be managed conservatively with antiplatelet agents, β-blockers, heparin and statins, if the patient is haemodynamically stable and coronary flow is adequate.
Self-adjointness of the semi-relativistic Pauli–Fierz Hamiltonian
Authors: Hidaka Takeru , Hiroshima Fumio
Published: August 2015

The spinless semi-relativistic Pauli–Fierz Hamiltonian [Formula: see text] in quantum electrodynamics is considered. Here p denotes a momentum operator, A a quantized radiation field, M ≥ 0, Hf the free Hamiltonian of a Boson Fock space and V an external potential. The self-adjointness and essential self-adjointness of H are shown. It is emphasized that it includes the case of M = 0. Furthermore, the self-adjointness and the essential self-adjointness of the semi-relativistic Pauli–Fierz model with a fixed total momentum P ∈ ℝd: [Formula: see text]

is also proven for arbitrary P.
Deterministic and stochastic algorithms for resolving the flow fields in ducts and networks using energy minimization
Authors: Sochi Taha
Published: August 2015

Several deterministic and stochastic multi-variable global optimization algorithms (Conjugate Gradient, Nelder–Mead, Quasi-Newton and global) are investigated in conjunction with energy minimization principle to resolve the pressure and volumetric flow rate fields in single ducts and networks of interconnected ducts. The algorithms are tested with seven types of fluid: Newtonian, power law, Bingham, Herschel–Bulkley, Ellis, Ree–Eyring and Casson. The results obtained from all those algorithms for all these types of fluid agree very well with the analytically derived solutions as obtained from the traditional methods which are based on the conservation principles and fluid constitutive relations. The results confirm and generalize the findings of our previous investigations that the energy minimization principle is at the heart of the flow dynamics systems. The investigation also enriches the methods of computational fluid dynamics for solving the flow fields in tubes and networks for various types of Newtonian and non-Newtonian fluids.
Experimental Implementation of Networked Chaotic Oscillators Based on Cross-Coupled Inverter Rings in a CMOS Integrated Circuit
Authors: Minati Ludovico
Published: August 2015

A novel chaotic oscillator based on "cross-coupled" inverter rings is presented. The oscillator consists of a 3-ring to which higher odd n-rings are progressively coupled via diodes and pass gates; it does not contain reactive or resistive elements, and is thus suitable for area-efficient implementation on a CMOS integrated circuit. Numerical simulation based on piece-wise linear approximation predicted the generation of positive spikes having approximately constant periodicity but highly variable cycle amplitude. Simulation Program with Integrated Circuit Emphasis (SPICE) simulations and experimental data from a prototype realized on 0.7 μm technology confirmed this finding, and demonstrated increasing correlation dimension (D2) as 5-, 7- and 9-rings were progressively coupled to the 3-ring. Experimental data from a ring of 24 such oscillator cells showed phase synchronization and partial amplitude synchronization (formation of small clusters), emerging depending on DC gate voltage applied at NMOS transistors implementing diffusive coupling between neighboring cells. Thanks to its small area, simple synchronizability and digital controllability, the proposed circuit enables experimental investigation of dynamical complexity in large networks of coupled chaotic oscillators, and may additionally be suitable for applications such as broadband signal and random number generation.
Crosstalk Induced Delay Analysis of Randomly Distributed Mixed CNT Bundle Interconnect
Authors: Majumder Manoj Kumar , Das Pankaj Kumar , Kumar Vobulapuram Ramesh , Kaushik Brajesh Kumar
Published: August 2015

In this paper, a more realistic analytical model for randomly distributed mixed carbon nanotube (CNT) bundle (MCB) is presented for the analysis of crosstalk induced delay. Several researchers have proposed analytical models for interconnects based on single-walled CNT (SWCNT), multi-walled CNT (MWCNT) bundle and most interestingly, spatially arranged mixed CNTs. Although, bundled SWCNTs and MWCNTs are easily realizable, but, practically it is almost impossible to fabricate a MCB with precise arrangements of SWCNTs and MWCNTs. Motivated by these facts, this paper presents a corner placement algorithm for randomly distributed SWCNTs and MWCNTs of different diameters in a MCB. The performance of MCB is compared with that of conventional bundled SWCNT and bundled MWCNT at different coupled interconnect lengths and spacing. Encouragingly, for a fixed cross-sectional area, the overall crosstalk induced delay of MCB reduces by 65.03% and 23.54% in comparison to the bundles having either SWCNTs or MWCNTs with smaller diameters, respectively. However, in contradiction to most of the previously reported results, bundled MWCNTs with larger diameters outperform the randomly distributed MCBs in terms of crosstalk performance.
On Gauss diagrams of periodic virtual knots
Authors: Bae Yongju , Lee In Sook
Published: August 2015

In this paper, we study the Gauss diagrams for periodic virtual knots (Theorem 3.1) and show that the virtual knot corresponding to a periodic Gauss diagram is equivalent to the periodic virtual knot whose factor is the virtual knot corresponding to the factor Gauss diagram (Theorem 3.2). We give formulae for the writhe polynomial and the affine index polynomial of periodic virtual knots by using those of factor knots (Corollary 4.2, Corollary 4.6).
Shear stress blunts tubuloglomerular feedback partially mediated by primary cilia and nitric oxide at the macula densa
Authors: Wang Lei , Shen Chunyu , Liu Haifeng , Wang Shaohui , Chen Xinshan , Roman Richard J. , Juncos Luis A. , Lu Yan , Wei Jin , Zhang Jie , Yip Kay-Pong , Liu Ruisheng
Published: August 2015

The present study tested whether primary cilia on macula densa serve as a flow sensor to enhance nitric oxide synthase 1 (NOS1) activity and inhibit tubuloglomerular feedback (TGF). Isolated perfused macula densa was loaded with calcein red and 4,5-diaminofluorescein diacetate to monitor cell volume and nitric oxide (NO) generation. An increase in tubular flow rate from 0 to 40 nl/min enhanced NO production by 40.0 ± 1.2%. The flow-induced NO generation was blocked by an inhibitor of NOS1 but not by inhibition of the Na/K/2Cl cotransporter or the removal of electrolytes from the perfusate. NO generation increased from 174.8 ± 21 to 276.1 ± 24 units/min in cultured MMDD1 cells when shear stress was increased from 0.5 to 5.0 dynes/cm2. The shear stress-induced NO generation was abolished in MMDD1 cells in which the cilia were disrupted using a siRNA to ift88. Increasing the NaCl concentration of the tubular perfusate from 10 to 80 mM NaCl in the isolated perfused juxtaglomerular preparation reduced the diameter of the afferent arteriole by 3.8 ± 0.1 μm. This response was significantly blunted to 2.5 ± 0.2 μm when dextran was added to the perfusate to increase the viscosity and shear stress. Inhibition of NOS1 blocked the effect of dextran on TGF response. In vitro, the effects of raising perfusate viscosity with dextran on tubular hydraulic pressure were minimized by reducing the outflow resistance to avoid stretching of tubular cells. These results suggest that shear stress stimulates primary cilia on the macula densa to enhance NO generation and inhibit TGF responsiveness.
Thrombospondin-2 deficiency in growing mice alters bone collagen ultrastructure and leads to a brittle bone phenotype
Authors: Manley Eugene , Perosky Joseph E. , Khoury Basma M. , Reddy Anita B. , Kozloff Kenneth M. , Alford Andrea I.
Published: August 2015

Thrombospondin-2 (TSP2) is a matricellular protein component of the bone extracellular matrix. Long bones of adult TSP2-deficient mice have increased endosteal bone thickness due to expansion of the osteoblast progenitor cell pool, and these cells display deficits in osteoblastic potential. Here, we investigated the effects of TSP2 deficiency on whole bone geometric and mechanical properties in growing 6-wk-old male and female wild-type and TSP2-knockout (KO) mice. Microcomputed tomography and mechanical testing were conducted on femora and L2 vertebrae to assess morphology and whole bone mechanical properties. In a second series of experiments, femoral diaphyses were harvested from wild-type and TSP2-KO mice. Detergent-soluble type I collagen content was determined by Western blot of right femora. Total collagen content was determined by hydroxyproline analysis of left femora. In a third series of experiments, cortical bone was dissected from the anterior and posterior aspects of the femoral middiaphysis and imaged by transmission electron microscopy to visualize collagen fibrils. Microcomputed tomography revealed minimal structural effects of TSP2 deficiency. TSP2 deficiency imparted a brittle phenotype on cortical bone. Femoral tissue mineral density was not affected by TSP2 deficiency. Instead, transmission electron microscopy revealed less intensely stained collagen fibrils with altered morphology in the extracellular matrix assembled by osteoblasts on the anterior surface of TSP2-KO femora. Femoral diaphyseal bone displayed comparable amounts of total collagen, but the TSP2-KO bones had higher levels of detergent-extractable type I collagen. Together, our data suggest that TSP2 is required for optimal collagen fibrillogenesis in bone and thereby contributes to normal skeletal tissue quality.
Cardiac Regeneration and Stem Cells
Authors: Zhang Yiqiang , Mignone John , MacLellan W. Robb
Published: August 2015

After decades of believing the heart loses the ability to regenerate soon after birth, numerous studies are now reporting that the adult heart may indeed be capable of regeneration, although the magnitude of new cardiac myocyte formation varies greatly. While this debate has energized the field of cardiac regeneration and led to a dramatic increase in our understanding of cardiac growth and repair, it has left much confusion in the field as to the prospects of regenerating the heart. Studies applying modern techniques of genetic lineage tracing and carbon-14 dating have begun to establish limits on the amount of endogenous regeneration after cardiac injury, but the underlying cellular mechanisms of this regeneration remained unclear. These same studies have also revealed an astonishing capacity for cardiac repair early in life that is largely lost with adult differentiation and maturation. Regardless, this renewed focus on cardiac regeneration as a therapeutic goal holds great promise as a novel strategy to address the leading cause of death in the developed world.
A Cross Layer Video Transmission Scheme Combining Geographic Routing and Short-Length Luby Transform Codes
Authors: Duan Pengrui , Liu Liang , Zhang Zhao
Published: August 2015

Video transmission is a real challenge for wireless multihop networks with high packet loss rate. This paper proposes a cross layer video transmission scheme which combines the geographic routing in network layer and the short-length Luby transform (LT) codes in transport layer. We first analyze the effect of bit error rate (BER) on the retransmission load and the effect of payload length and LT symbols size on network efficiency. Then, based on the product of the link quality and the distance from destination, we design a routing metric for geographic routing. We further propose a cross layer transmission scheme, which adaptively adjusts payload length to encapsulate short-length LT encoded symbols and selects routes based on the new routing metric. The simulation results show that our cross layer scheme can decrease the decoding overhead and the packet loss rate, while improving the video transmission quality and the network efficiency.
A Discrete-Time Queue with Preferred Customers and Partial Buffer Sharing
Authors: Zhou Shizhong , Liu Liwei , Li Jianjun
Published: August 2015

We analyze a discrete-time Geo/Geo/1 queueing system with preferred customers and partial buffer sharing. In this model, customers arrive according to geometrical arrival processes with probabilityλ. If an arriving customer finds the server idle, he begins instantly his services. Otherwise, if the server is busy at the arrival epoch, the arrival either interrupts the customer being served to commence his own service with probabilityθ(the customer is called the preferred customer) or joins the waiting line at the back of the queue with probabilityθ~(the customer is called the normal customer) if permitted. The interrupted customer joins the waiting line at the head of the queue. If the total number of customers in the system is equal to or more than thresholdN, the normal customer will be ignored to enter into the system. But this restriction is not suitable for the preferred customers; that is, this system never loses preferred customers. A necessary and sufficient condition for the system to be stable is investigated and the stationary distribution of the queue length of the system is also obtained. Further, we develop a novel method to solve the probability generating function of the busy period of the system. The distribution of sojourn time of a customer in the server and the other indexes are acquired as well.
Isolated Hyperreligiosity in a Patient with Temporal Lobe Epilepsy
Authors: Garcia-Santibanez Rocio , Sarva Harini
Published: August 2015

A 40-year-old man with history of temporal lobe epilepsy presented to the emergency department with hyperreligiosity after medication noncompliance. After medications were resumed, he returned to baseline. Many famous prophets are believed to have suffered epilepsy. Waxman and Geschwind described a group of traits in patients with temporal lobe epilepsy consisting of hyperreligiosity, hypergraphia, altered sexual behavior, aggressiveness, preoccupation with details, and circumstantiality. The incidence of religious experiences ranges from 0.3 to 3.1 percent in patients with epilepsy. Religious experiences can be ictal, interictal, or postictal. Treatment is aimed at the underlying seizure etiology.
Preparation and Investigation of the Microtribological Properties of Graphene Oxide and Graphene Films via Electrostatic Layer‐by‐Layer Self‐Assembly
Authors: Hu Yongshou , Ma Haibing , Liu Wei , Lin Qianqian , Liu Bin
Published: August 2015

Graphene oxide (GO) films with controlled layers, deposited on single‐crystal silicon substrates, were prepared by electrostatic self‐assembly of negatively charged GO sheets. Afterward, graphene films were prepared by liquid‐phase reduction of as‐prepared GO films using hydrazine hydrate. The microstructures and microtribological properties of the samples were studied using X‐ray photoelectron spectroscopy, Raman spectroscopy, X‐ray diffraction, UV‐vis absorption spectroscopy, water contact angle measurement, and atomic force microscopy. It is found that, whether GO films or graphene films, the adhesion force and the coefficients of friction both show strong dependence on the number of self‐assembled layers, which both allow a downward trend as the number of self‐assembled layers increases due to the interlayer sliding and the puckering effect when the tip slipped across the top surface of the films. Moreover, in comparison with the GO films with the same self‐assembled layers, the graphene films possess lower adhesion force and coefficient of friction attributed to the difference of surface functional groups.
Size‐Dependent Optical Properties of Nanoscale and Bulk Long Persistent Phosphor SrAl2O4:Eu2+, Dy3+
Authors: Duan Xiaoxia , Yi Lixin , Zhang Xiqing , Huang Shihua
Published: August 2015

Nanoscale long persistent phosphor SrAl2O4:Eu2+, Dy3+ was prepared by autocombustion of citrate gel. The energy level shift of activator Eu2+ and coactivator Dy3+ was analyzed according to the emission and the excitation spectra. The band gap change of SrAl2O4 and the resulting trap depth change with particle size were discussed on the basis of analyzing the visible spectra, the vacuum ultraviolet (VUV) excitation spectra, and the thermoluminescence (TL) spectra. The fluorescence quenching and the shallow traps originating from surface adsorption or surface defects explain the weak initial persistent phosphorescence and the fast phosphorescence decay in nanometer SrAl2O4:Eu2+, Dy3+. It is confirmed that energy level, band gap, trap depth, defect, and surface adsorption are deeply related with each other in this nanoscale long persistent phosphor.
Three‐Dimensional Finite Element Analysis of Anterior Single Implant‐Supported Prostheses with Different Bone Anchorages
Authors: Verri Fellippo Ramos , Santiago Júnior Joel Ferreira , Almeida Daniel Augusto de Faria , Verri Ana Caroline Gonçales , de Souza Batista Victor Eduardo , Lemos Cleidiel Aparecido Araujo , Noritomi Pedro Yoshito , Pellizzer Eduardo Piza
Published: August 2015

The aim of this study was to evaluate the stress distribution of monocortical and bicortical implant placement of external hexagon connection in the anterior region of the maxilla by 3D finite element analysis (FEA). 3D models were simulated to represent a bone block of anterior region of the maxilla containing an implant (4.0 × 10.0 mm) and an implant‐supported cemented metalloceramic crown of the central incisor. Different techniques were tested (monocortical, bicortical, and bicortical associated with nasal floor elevation). FEA was performed in FEMAP/NeiNastran software using loads of 178 N at 0°, 30°, and 60° in relation to implant long axis. The von Mises, maximum principal stress, and displacement maps were plotted for evaluation. Similar stress patterns were observed for all models. Oblique loads increased the stress concentration on fixation screws and in the cervical area of the implants and bone around them. Bicortical technique showed less movement tendency in the implant and its components. Cortical bone of apical region showed increase of stress concentration for bicortical techniques. Within the limitations of this study, oblique loading increased the stress concentrations for all techniques. Moreover, bicortical techniques showed the best biomechanical behavior compared with monocortical technique in the anterior maxillary area.
Convexity of Ruin Probability and Optimal Dividend Strategies for a General Lévy Process
Authors: Yin Chuancun , Yuen Kam Chuen , Shen Ying
Published: August 2015

We consider the optimal dividends problem for a company whose cash reserves follow a general Lévy process with certain positive jumps and arbitrary negative jumps. The objective is to find a policy which maximizes the expected discounted dividends until the time of ruin. Under appropriate conditions, we use some recent results in the theory of potential analysis of subordinators to obtain the convexity properties of probability of ruin. We present conditions under which the optimal dividend strategy, among all admissible ones, takes the form of a barrier strategy.
The Type I Generalized Half-Logistic Distribution Based on Upper Record Values
Authors: Kumar Devendra , Jain Neetu , Gupta Shivani
Published: August 2015

We consider the type I generalized half-logistic distribution and derive some new explicit expressions and recurrence relations for marginal and joint moment generating functions of upper record values. Here we show the computations for the first four moments and their variances. Next we show that results for record values of this distribution can be derived from our results as special cases. We obtain the characterization result of this distribution on using the recurrence relation for single moment and conditional expectation of upper record values. We obtain the maximum likelihood estimators of upper record values and their confidence intervals. Also, we compute the maximum likelihood estimates of the parameters of upper record values and their confidence intervals. At last, we present one real case data study to emphasize the results of this paper.
Auraptene, a Major Compound of Supercritical Fluid Extract of Phalsak (CitrusHassaku Hort ex Tanaka), Induces Apoptosis through the Suppression of mTOR Pathways in Human Gastric Cancer SNU-1 Cells
Authors: Moon Jeong Yong , Kim Hyeonji , Cho Somi Kim
Published: August 2015

The supercritical extraction method is a widely used process to obtain volatile and nonvolatile compounds by avoiding thermal degradation and solvent residue in the extracts. In search of phytochemicals with potential therapeutic application in gastric cancer, the supercritical fluid extract (SFE) of phalsak (Citrushassaku Hort ex Tanaka) fruits was analyzed by gas chromatography-mass spectrometry (GC-MS). Compositional analysis in comparison with the antiproliferative activities of peel and flesh suggested auraptene as the most prominent anticancer compound against gastric cancer cells. SNU-1 cells were the most susceptible to auraptene-induced toxicity among the tested gastric cancer cell lines. Auraptene induced the death of SNU-1 cells through apoptosis, as evidenced by the increased cell population in the sub-G1 phase, the appearance of fragmented nuclei, the proteolytic cleavage of caspase-3 and poly(ADP-ribose) polymerase (PARP) protein, and depolarization of the mitochondrial membrane. Interestingly, auraptene induces an increase in the phosphorylation of Akt, which is reminiscent of the effect of rapamycin, the mTOR inhibitor that triggers a negative feedback loop on Akt/mTOR pathway. Taken together, these findings provide valuable insights into the anticancer effects of the SFE of the phalsak peel by revealing that auraptene, the major compound of it, induced apoptosis in accompanied with the inhibition of mTOR in SNU-1 cells.
Relationship between Postural Deformities and Frontal Function in Parkinson’s Disease
Authors: Ninomiya Satoko , Morita Akihiko , Teramoto Hiroko , Akimoto Takayoshi , Shiota Hiroshi , Kamei Satoshi
Published: August 2015

Postural deformities and executive dysfunction (ED) are common symptoms of Parkinson’s disease (PD); however, the relationship between postural deformities and ED in patients with PD remains unclear. This study assessed the relationship between postural deformities and ED in patients with PD. Sixty-five patients with sporadic PD were assessed for the severity of postural deformities and executive function. The severity of postural deformities was scored using the United Parkinson’s Disease Rating Scale item 28 score: no postural deformity (0), mild postural deformities (1), or severe postural deformities (2–4). Executive function was assessed using the Behavioral Assessment of the Dysexecutive Syndrome (BADS) and an age-controlled standardized BADS score <70 was defined as ED. Age-controlled standardized BADS scores were compared across the three groups using the Kruskal-Wallis test. Relationship between ED and the severity of postural deformities was assessed using the Mann-WhitneyUtest. Age-controlled standardized BADS score significantly differed among the three groupsP=0.005. ED was significantly related to the severity of postural deformitiesP=0.0005. The severity of postural deformities was associated with a lower age-controlled standardized BADS score and ED, and these findings suggest that postural deformities were associated with frontal dysfunction in patients with PD.
A Self-Adaptive Particle Swarm Optimization Based Multiple Source Localization Algorithm in Binary Sensor Networks
Authors: Cheng Long , Wang Yan , Li Shuai
Published: August 2015

With the development of wireless communication and sensor techniques, source localization based on sensor network is getting more attention. However, fewer works investigate the multiple source localization for binary sensor network. In this paper, a self-adaptive particle swarm optimization based multiple source localization method is proposed. A detection model based on Neyman-Pearson criterion is introduced. Then the maximum likelihood estimator is employed to establish the objective function which is used to estimate the location of sources. Therefore, the multiple-source localization problem is transformed into optimization problem. In order to improve the ability of global search of particle swarm optimization, the self-adaptive particle swarm optimization is used to solve this problem. Various simulations have been conducted, and the results show that the proposed method owns higher localization accuracy in comparison with other methods.
Implementation of Secondary Index on Cloud Computing NoSQL Database in Big Data Environment
Authors: Chang Bao Rong , Tsai Hsiu-Fen , Chen Chia-Yen , Huang Chien-Feng , Hsu Hung-Ta
Published: August 2015

This paper introduces the combination of NoSQL database HBase and enterprise search platform Solr so as to tackle the problem of the secondary index function with fast query. In order to verify the effectiveness and efficiency of the proposed approach, the assessment using Cost-Performance ratio has been done for several competitive benchmark databases and the proposed one. As a result, our proposed approach outperforms the other databases and fulfills secondary index function with fast query in NoSQL database. Moreover, according to the cross-sectional analysis, the proposed combination of HBase and Solr database is capable of performing an excellent query/response in a big data environment.
Chirp Spread Spectrum Transceiver Design and Implementation for Real Time Locating System
Authors: Kim Sangdeok , Chong Jong-Wha
Published: August 2015

A chirp spread spectrum (CSS) transceiver architecture for IEEE 802.15.4a is proposed and implemented. In the transmitter, the size of the read-only memory that stores CSS signal samples for the chirp modulator is reduced by removing duplicate samples among subchirps. In the receiver, a matched filter is utilized to remove the other band noise caused by the band hopping property of CSS. A robust time synchronizer and chirp demodulator based on the matched filter are proposed. Low complexity architectures of the matched filter and biorthogonal decoder are also proposed. All of the proposed architectures are implemented in the field-programmable gate array chip and verified.
An Adaptive Spanning Tree-Based Data Collection Scheme in Wireless Sensor Networks
Authors: Zhang Yi , Pu Juhua , Liu Xingwu , Chen Zun
Published: August 2015

In-network data aggregation is a widely used method for collecting data efficiently in wireless sensor networks (WSNs). The authors focus on how to achieve high aggregation efficiency and prolonging networks’ lifetime. Firstly, this paper proposes an adaptive spanning tree algorithm (AST), which can adaptively build and adjust an aggregation spanning tree. Owing to the strategies of random waiting and alternative father nodes, AST can achieve a relatively balanced spanning tree and flexible tree adjustment. Then a redundant aggregation scheme (RAG) is illustrated. In RAG, interior nodes help to forward data for their sibling nodes and thus provide reliable data transmission for WSN. Finally, the simulations demonstrate that (1) AST can prolong the lifetime and (2) RAG makes a better trade-off between storage and aggregation ratio, comparing to other aggregation schemes.
Lightweight Anomaly Detection for Wireless Sensor Networks
Authors: Cheng Pu , Zhu Minghua
Published: August 2015

Anomaly detection in wireless sensor networks (WSNs) is critical to ensure the quality of senor data, secure monitoring, and reliable detection of interesting and critical events. The main challenge of anomaly detection algorithm in WSNs is identifying anomalies with high accuracy while consuming minimal resource of the network. In this paper two lightweight anomaly detection algorithms LADS and LADQA are proposed for WSNs. Both algorithms utilize the one-class quarter-sphere support vector machine (QSSVM) and convert the linear optimization problem of QSSVM to a sort problem for the reduced computational complexity. Experimental results show that the proposed algorithms can keep the lower computational complexity without reducing the accuracy for anomaly detection, compared to QSSVM.
Design of Randomly Deployed Heterogeneous Wireless Sensor Networks by Algorithms Based on Swarm Intelligence
Authors: Lee Joon-Woo , Kim Won
Published: August 2015

This paper reports the design of a randomly deployed heterogeneous wireless sensor network (HWSN) with two types of nodes: a powerful node and an ordinary node. Powerful nodes, such as Cluster Heads (CHs), communicate directly to the data sink of the network, and ordinary nodes sense the desired information and transmit the processed data to powerful nodes. The heterogeneity of HWSNs improves the networks lifetime and coverage. This paper focuses on the design of a random network among HWSNs. In the design of a random HWSN, this paper uses algorithms based on the binary-valued versions of swarm intelligence, such as Particle Swarm Optimization (PSO), Artificial Bee Colony (ABC), and Ant Colony Optimization (ACO). The design is then considered to be an optimization problem of how many powerful and ordinary nodes will combine to minimize the network cost, while guaranteeing a desired coverage during a given period. Simulation results show the performance of each algorithm for solving the defined optimization problem.
Localization Algorithm in Wireless Sensor Networks Based on Multiobjective Particle Swarm Optimization
Authors: Sun Ziwen , Tao Li , Wang Xinyu , Zhou Zhiping
Published: August 2015

Based on multiobjective particle swarm optimization, a localization algorithm named multiobjective particle swarm optimization localization algorithm (MOPSOLA) is proposed to solve the multiobjective optimization localization issues in wireless sensor networks. The multiobjective functions consist of the space distance constraint and the geometric topology constraint. The optimal solution is found by multiobjective particle swarm optimization algorithm. Dynamic method is adopted to maintain the archive in order to limit the size of archive, and the global optimum is obtained according to the proportion of selection. The simulation results show considerable improvements in terms of localization accuracy and convergence rate while keeping a limited archive size by a method using the global optimal selection operator and dynamically maintaining the archive.