bluuebunny/crossref_metadata_2025 huggingface dataset:
Towards an Open Source Analysis Toolbox for Street Network Comparison: Indicators, Tools and Results of a Comparison of OSM and the Official Austrian Reference Graph
Authors: Graser Anita , Straub Markus , Dragaschnig Melitta
Published: October 2013

This article presents a novel open source toolbox for street network comparison based on the Sextante geoprocessing framework for the open source Geographic Information System Quantum GIS (QGIS). In the spirit of open science, the toolbox enables researchers worldwide to assess the quality of street networks such as OpenStreetMap (OSM) by calculating key performance indicators commonly used in street network comparison studies. Additionally, we suggest two new performance indicators for turn restriction and one‐way street comparisons specifically aimed at testing street network quality for routing. We demonstrate the use of this toolbox by comparing OSM and the official Austrian reference graph “Graph Integration Platform” (GIP) in the greater Vienna region.
Incidence of and risk factors for neonatal jaundice among newborns in southern Nepal
Authors: Scrafford Carolyn G. , Mullany Luke C. , Katz Joanne , Khatry Subarna K. , LeClerq Steven C. , Darmstadt Gary L. , Tielsch James M.
Published: October 2013

Objective

To quantify the incidence of and risk factors for neonatal jaundice among infants referred for care from a rural, low‐resource, population‐based cohort in southern Nepal.

Methods

Study participants were 18 985 newborn infants born in Sarlahi District in southern Nepal from May 2003 through January 2006 who participated in a cluster‐randomised, placebo‐controlled, community‐based trial to evaluate the effect of newborn chlorhexidine cleansing on neonatal mortality and morbidity. Jaundice was assessed based on visual assessment of the infant by a study worker and referral for care. Adjusted relative risks (RR) were estimated to identify risk factors for referral for neonatal jaundice using Poisson regression.

Results

The incidence of referral for neonatal jaundice was 29.3 per 1000 live births (95% confidence interval: 26.9, 31.7). Male sex, high birth weight, breastfeeding patterns, warm air temperature, primiparity, skilled birth attendance, place of delivery, prolonged labour, oil massage, paternal education and ethnicity were significant risk factors (P‐values < 0.01). After multivariable adjustment, sex, birth weight, difficulty feeding, prolonged labour, primiparity, oil massage, ambient air temperature and ethnicity remained important factors. Among infants with difficulty feeding, exclusive breastfeeding was a risk factor for neonatal jaundice, whereas exclusive breastfeeding was protective among infants with no report of difficulty feeding.

Conclusions

Several known risk factors for neonatal jaundice in a low‐resource setting were confirmed in this study. Unique observed associations of jaundice with ambient air temperature and oil massage may be explained by the opportunity for phototherapy based on the cultural practices of this study population. Future research should investigate the role of an infant's difficulty in feeding as a potential modifier in the association between exclusive breastfeeding and jaundice.
Dissection of two major components of the post‐zygotic hybridization barrier in rice endosperm
Authors: Sekine Daisuke , Ohnishi Takayuki , Furuumi Hiroyasu , Ono Akemi , Yamada Toshihiro , Kurata Nori , Kinoshita Tetsu
Published: October 2013

A post‐zygotic hybridization barrier is often observed in the endosperm of seeds produced by interspecific or interploidy crosses. In Arabidopsis thaliana, for example, hybrid endosperm from both types of cross shows altered timing of cellularization and an altered rate of nuclear divisions. Therefore, it has been proposed that interspecific and interploidy crosses share common molecular mechanisms for establishment of an effective species barrier. However, these two types of hybridization barrier may be initiated by different intrinsic cues: the interspecific cross barrier arises after hybridization of genomes with differences in DNA sequences, while the interploidy cross barrier arises after hybridization of genomes with the same DNA sequences but differences in ploidy levels. In this study, we performed interploidy crosses to identify components of the post‐hybridization barrier in the endosperm of rice. We performed an intra‐cultivar cross of autotetraploid (4n) × diploid (2n) rice, and found precocious cellularization and a decreased rate of nuclear division in the syncytial endosperm. By contrast, seeds from the reciprocal cross showed delayed cellularization and an increased rate of nuclear division. This differential effect on nuclear division rates contrasts with the outcome of rice interspecific crosses, which were previously shown to have altered timing of cellularization without any change in nuclear division rates. Thus, we propose that the post‐zygotic hybridization barrier in rice endosperm has two separable components, namely control of the timing of cellularization and control of the nuclear division rates in the syncytial stage of endosperm development.
Synthetic nucleases for genome engineering in plants: prospects for a bright future
Authors: Puchta Holger , Fauser Friedrich
Published: October 2013

By inducing double‐strand breaks (DSB), it is possible to initiate DNA recombination. For a long time, it was not possible to use DSB induction for efficient genome engineering due to the lack of a means to target DSBs to specific sites. This limitation was overcome by development of modified meganucleases and synthetic DNA‐binding domains. Domains derived from zinc‐finger transcription factors or transcription activator‐like effectors may be designed to recognize almost any DNA sequence. By fusing these domains to the endonuclease domains of a class II restriction enzyme, an active endonuclease dimer may be formed that introduces a site‐specific DSB. Recent studies demonstrate that gene knockouts via non‐homologous end joining or gene modification via homologous recombination are becoming routine in many plant species. By creating a single genomic DSB, complete knockout of a gene, sequence‐specific integration of foreign DNA or subtle modification of individual amino acids in a specific protein domain may be achieved. The induction of two or more DSBs allows complex genomic rearrangements such as deletions, inversions or the exchange of chromosome arms. The potential for controlled genome engineering in plants is tremendous. The recently discovered RNA‐based CRISPR/Cas system, a new tool to induce multiple DSBs, and sophisticated technical applications, such as the in planta gene targeting system, are further steps in this development. At present, the focus remains on engineering of single genes; in the future, engineering of whole genomes will become an option.
Experimental and Numerical Investigations of Effects of Flow Control Devices Upon Flat-Plate Film Cooling Performance
Authors: Kawabata Hirokazu , Funazaki Ken-ichi , Nakata Ryota , Takahashi Daichi
Published: October 2013

This study deals with the experimental and numerical studies of the effect of flow control devices (FCDs) on the film cooling performance of a circular cooling hole on a flat plate. Two types of FCDs with different heights are examined in this study, where each of them is mounted to the flat plate upstream of the cooling hole by changing its lateral position with respect to the hole centerline. In order to measure the film effectiveness as well as heat transfer downstream of the cooling hole with upstream FCD, a transient method using a high-resolution infrared camera is adopted. The velocity field downstream of the cooling hole is captured by 3D laser Doppler velocimeter (LDV). Furthermore, the aerodynamic loss associated with the cooling hole with/without FCD is measured by a total pressure probe rake. The experiments are carried out at blowing ratios ranging from 0.5 to 1.0. In addition, numerical simulations are also made to have a better understanding of the flow field. LES approach is employed to solve the flow field and visualize the vortex structure around the cooling hole with FCD. When a taller FCD is mounted to the plate, the film effectiveness tends to increase due to the vortex structure generated by the FCD. As FCD is laterally shifted from the centerline, the film effectiveness increases, while the lift-off of cooling air is also promoted when FCD is put on the center line.
Finite Element Model of the Knee for Investigation of Injury Mechanisms: Development and Validation
Authors: Kiapour Ali , Kiapour Ata M. , Kaul Vikas , Quatman Carmen E. , Wordeman Samuel C. , Hewett Timothy E. , Demetropoulos Constantine K. , Goel Vijay K.
Published: October 2013

Multiple computational models have been developed to study knee biomechanics. However, the majority of these models are mainly validated against a limited range of loading conditions and/or do not include sufficient details of the critical anatomical structures within the joint. Due to the multifactorial dynamic nature of knee injuries, anatomic finite element (FE) models validated against multiple factors under a broad range of loading conditions are necessary. This study presents a validated FE model of the lower extremity with an anatomically accurate representation of the knee joint. The model was validated against tibiofemoral kinematics, ligaments strain/force, and articular cartilage pressure data measured directly from static, quasi-static, and dynamic cadaveric experiments. Strong correlations were observed between model predictions and experimental data (r > 0.8 and p < 0.0005 for all comparisons). FE predictions showed low deviations (root-mean-square (RMS) error) from average experimental data under all modes of static and quasi-static loading, falling within 2.5 deg of tibiofemoral rotation, 1% of anterior cruciate ligament (ACL) and medial collateral ligament (MCL) strains, 17 N of ACL load, and 1 mm of tibiofemoral center of pressure. Similarly, the FE model was able to accurately predict tibiofemoral kinematics and ACL and MCL strains during simulated bipedal landings (dynamic loading). In addition to minimal deviation from direct cadaveric measurements, all model predictions fell within 95% confidence intervals of the average experimental data. Agreement between model predictions and experimental data demonstrates the ability of the developed model to predict the kinematics of the human knee joint as well as the complex, nonuniform stress and strain fields that occur in biological soft tissue. Such a model will facilitate the in-depth understanding of a multitude of potential knee injury mechanisms with special emphasis on ACL injury.
Steam Turbine Rotor Blade Cascades Aerodynamic Performance Research at Off-Design Incidence
Authors: Feng Zi-Ming , Zhang Jin-Dong , Gu Hui-Bin
Published: October 2013

A steam turbine rotor cascades aerodynamic performance test are performed in annular cascade wind tunnel. The tested blade is curved and has rear-loaded profile characteristic. The main goal of this research project is to measure the off-design incidence aerodynamic performance, such as static pressure coefficient, total pressure loss and streamline.

The test result indicates that incidence variation has little influence to the static pressure coefficient along blade profile, but has relatively significant influence to the profile loss. The blade profile loss increase continuously with the incidence sequence at 0°, −10° and +10°. At the tested incidence, the secondary flow intensity was very weak and its influence area was very small too. It states the aft-loaded blade profile has good incidence suitability.
Effective Radiation Modelling Technique for Transient Temperature Prediction of Gas Turbine Components
Authors: Cherukupalli S. Y. Suresh , Nelanti Krishna , Gujar Kamlesh G. , Palle John Sunil
Published: October 2013

Gas Turbine engine components like Combustor, Diffuser, and Turbines are subjected to very high temperatures. Predicting accurate temperatures of such components demand accurate Radiation modeling along with Conduction and Convection. Radiation heat transfer modeling is very complex due to non linear dependence on temperature and additional parameters driving the heat transfer like shape factor, emissivity, surface area and absorbtivity of material.

The commercial software ANSYS developed various Radiation techniques like ‘Radiation Matrix’, ‘Radiosity’ and ‘Radiation modeling between a surface and a point’. A detailed study has been carried out to compare different Radiation models. The ease of building the model, computational time, accuracy, and limitations are thoroughly examined. It is found that all existing methods have some limitations in accuracy, computational time or system requirements.

To overcome some of these limitations, a new technique called ‘Surface Effect Element Method’ is proposed in this paper. This method uses ‘Radiosity’ for the shape factor computation and ‘Radiation modeling between a surface and a point’ for modeling Radiation between two surfaces. The average of one surface temperature is transferred to a single point which in turn is used to model the Radiation to the second surface and the same procedure is repeated for the second surface too.

A detailed study is carried out and the proposed technique is compared against the available methods. The new technique enables accurate computation of transient temperatures for gas turbine components leading to accurate life prediction for these components. It is shown that ‘Surface Effect Element Method’ has comparable accuracy but significantly lower cycle time and efforts compared to existing methods.
Internal Wall-Jet Film Cooling With Tangential Coolant Holes
Authors: Shine S. R. , Kumar S. Sunil , Suresh B. N.
Published: October 2013

Experimental and numerical investigations are carried out to analyze the effect of tangential coolant injection on overall film cooling performance in a cylindrical test section simulating a high curvature surface. Experiments are conducted using hot air as core gas and nitrogen gas as coolant injected through cylindrical holes inclined at 30-degrees to the core gas flow. A three-dimensional multi-species numerical model is formulated using the finite volume formulation and is validated using the obtained experimental data. Simulation results indicate that an optimum blowing ratio exists for which the effectiveness is maximum. The conjugate effectiveness is observed to be higher than adiabatic effectiveness values except in the vicinity of injection owing to the wall conduction effects. Numerical analysis performed with an annular slot placed at the exit of the coolant holes showed an increase in the effectiveness by 21 % compared to the base hole. It is expected that the knowledge acquired in this study has the potential to support new ideas in gas turbine film cooling techniques such as turbine casing film cooling.
Thermal Analysis of Gas Turbine Bearing Compartment During Normal Operation Period
Authors: Kanike Nagaraju , Taluru Danteswara , Nelanti Krishna , Gujar Kamlesh G.
Published: October 2013

Modern Gas turbine efficiency increase accompanied by higher turbine inlet temperature, pressure levels and rotor speeds. These demands an accurate thermal analysis of bearing compartments as large load transferred through bearings and heat load from surrounding environment. Two phase flow air &oil) is common in bearing compartments and it makes heat transfer coefficient estimation a difficult task. Bearing friction, oil churning, seals heat generations and heat input from the surroundings need to be considered accurately to predict the compartment temperatures at various operating conditions.

In addition to analysis for operating conditions, bearing compartment soak back analysis is also critical for safe operation of bearings. Absence of oil flow during shutdown of the engine can cause coking of oil film due to heat soak from the hot surroundings. Accurate soak back analysis is therefore required to simulate the thermal response of the bearing compartment during shutdown.

For the normal operating conditions, detailed numerical investigations are carried out to predict (i) optimal oil flow rate at a given rotor speed, (ii) maximum rotor speed allowed for the specified oil flow rate and (iii) the heat transfer rates for various air fractions of the oil & air mixture. The results are validated against available Engine data on scavenge oil and bearing race metal temperatures.
Numerical Investigation of Combustion Characteristics in a Liquid Fuelled Can Combustor
Authors: Pandey Vivek , De Ashoke , Kushari Abhijit
Published: October 2013

In the present study, reacting flow in a can combustor is numerically simulated and the results are compared with the data available in open literature. Different grids are considered in order to compare air mass-flow distributions through air entry ports. The fuel used for reacting flow calculations is a kerosene surrogate. In combination with continuity and momentum equations, the transport equations for mean mixture fraction (f) and mixture fraction variance (f″) are solved, linking the instantaneous thermo-chemical state of the fluid through this conserved scalar and its variance. Three sets of atomizer air swirls with swirl number (SN) 0.8, 1, and 1.2 have been tested along with different RANS based turbulence models. It is observed that k-ω-sst model appears to exhibit most realistic solutions in terms of the pattern factor and peak exit temperature. This is due to better prediction of turbulence kinetic energy generation at the primary zone of the combustor. However, the swirl in atomizing air plays a critical role in anchoring the flame in the primary zone of the combustor due to formation of recirculation bubble. Moreover, it is observed that the spray stream is convected downstream for a swirl number slightly below 1.0, thereby affecting the pattern factor of the combustor.
Spatial and temporal performance of 3D optical surface imaging for real‐time head position tracking
Authors: Wiersma Rodney D. , Tomarken S. L. , Grelewicz Zachary , Belcher Andrew H. , Kang Hyejoo
Published: October 2013

Purpose:

The spatial and temporal tracking performance of a commercially available 3D optical surface imaging system is evaluated for its potential use in frameless stereotactic radiosurgery head tracking applications.

Methods:

Both 3D surface and infrared (IR) marker tracking were performed simultaneously on a head phantom mounted on anxyz motion stage and on four human subjects. To allow spatial and temporal comparison on human subjects, three points were simultaneously monitored, including the upper facial region (3D surface), a dental plate (IR markers), and upper forehead (IR markers).

Results:

For both static and dynamic phantom studies, the 3D surface tracker was found to have a root mean squared error (RMSE) of approximately 0.30 mm for region‐of‐interest (ROI) surface sizes greater than 1000 vertex points. Although, the processing period (1/fps) of the 3D surface system was found to linearly increase as a function of the number of ROI vertex points, the tracking accuracy was found to be independent of ROI size provided that the ROI was sufficiently large and contained features for registration. For human subjects, the RMSE between 3D surface tracking and IR marker tracking modalities was 0.22 mm left‐right (x‐axis), 0.44 mm superior‐inferior (y‐axis), 0.27 mm anterior‐posterior (z‐axis), 0.29° pitch (around x‐axis), 0.18° roll (around y‐axis), and 0.15° yaw (around z‐axis).

Conclusions:

3D surface imaging has the potential to provide submillimeter level head motion tracking. This is provided that a highly accurate camera‐to‐LINAC frame of reference calibration can be performed and that the reference ROI is of sufficient size and contains suitable surface features for registration.
CT image assessment by low contrast signal detectability evaluation with unknown signal location
Authors: Popescu Lucretiu M. , Myers Kyle J.
Published: October 2013

Purpose:

To devise a new methodology for CT image quality evaluation in order to assess the dose reduction potential of new iterative reconstruction algorithms (IRA).

Methods:

Because of the nonlinear behavior of IRA, the authors propose a task‐based methodology consisting of measuring the detectability of small, low contrast signals at random locations. The authors test, via simulations, a phantom design that facilitates human and numerical observer studies in such conditions. The setup allows for the random selection of regions of interest (ROI) around each signal, so that the relative signal location is unknown if the ROIs are shown separately. With such a setup one can perform signal detectability measurements with a variety of image reading arrangements and data analysis methods. In this work, the authors demonstrate the use of the localization relative operating characteristic method. The phantom design also allows for efficient image evaluation utilizing an automatic signal search technique and a recently developed nonparametric data analysis method using the exponential transformation of the free response characteristic curve.

Results:

The authors present the application of these methods by performing a comparison between the filtered back projection (FBP) algorithm and a polychromatic iterative image reconstruction algorithm. In this generic illustration of the image evaluation framework, the expected improved performance of the IRA over FBP is confirmed.

Conclusions:

The results demonstrate the ability of these methods to determine signal detectability indices with good accuracy with only a small number, of the order of a few tens, of image samples.
Dimensionality and noise in energy selective x‐ray imaging
Authors: Alvarez Robert E.
Published: October 2013

Purpose:

To develop and test a method to quantify the effect of dimensionality on the noise in energy selective x‐ray imaging.

Methods:

The Cramèr‐Rao lower bound (CRLB), a universal lower limit of the covariance of any unbiased estimator, is used to quantify the noise. It is shown that increasing dimensionality always increases, or at best leaves the same, the variance. An analytic formula for the increase in variance in an energy selective x‐ray system is derived. The formula is used to gain insight into the dependence of the increase in variance on the properties of the additional basis functions, the measurement noise covariance, and the source spectrum. The formula is also used with computer simulations to quantify the dependence of the additional variance on these factors. Simulated images of an object with three materials are used to demonstrate the trade‐off of increased information with dimensionality and noise. The images are computed from energy selective data with a maximum likelihood estimator.

Results:

The increase in variance depends most importantly on the dimension and on the properties of the additional basis functions. With the attenuation coefficients of cortical bone, soft tissue, and adipose tissue as the basis functions, the increase in variance of the bone component from two to three dimensions is 1.4 × 103. With the soft tissue component, it is 2.7 × 104. If the attenuation coefficient of a high atomic number contrast agent is used as the third basis function, there is only a slight increase in the variance from two to three basis functions, 1.03 and 7.4 for the bone and soft tissue components, respectively. The changes in spectrum shape with beam hardening also have a substantial effect. They increase the variance by a factor of approximately 200 for the bone component and 220 for the soft tissue component as the soft tissue object thickness increases from 1 to 30 cm. Decreasing the energy resolution of the detectors increases the variance of the bone component markedly with three dimension processing, approximately a factor of 25 as the resolution decreases from 100 to 3 bins. The increase with two dimension processing for adipose tissue is a factor of two and with the contrast agent as the third material for two or three dimensions is also a factor of two for both components. The simulated images show that a maximum likelihood estimator can be used to process energy selective x‐ray data to produce images with noise close to the CRLB.

Conclusions:

The method presented can be used to compute the effects of the object attenuation coefficients and the x‐ray system properties on the relationship of dimensionality and noise in energy selective x‐ray imaging systems.
Automatic localization of the fetal cerebellum on 3D ultrasound volumes
Authors: Liu Xinyu , Yu Jinhua , Wang Yuanyuan , Chen Ping
Published: October 2013

Purpose:

Assessment of the fetal cerebellar volume on 3D ultrasound data sets is very important in the clinical evaluation of the fetal growth and health. However, the irregular shape of the cerebellum and the strong artifacts of ultrasound images complicate the segmentation without manual intervention. In this paper, the authors propose an approach to locate the cerebellum automatically, which is considered as a prework of the segmentation.

Methods:

The authors present a weighted Hough transform and a constrained randomized Hough transform to detect the fetal brain midline and the skull, respectively. By combining the location information of these two structures with local image features, a constrained probabilistic boosting tree is then proposed to search the cerebellum.

Results:

This algorithm was tested on ultrasound volumes of the fetal head with the gestational age ranging from 20 to 33 weeks. Compared with manual measurements, this algorithm obtained a satisfactory performance with the mean Dice similarity coefficient of 0.92 and the average processing time of 0.75 s per case.

Conclusions:

The results demonstrate that the proposed method is an automatic, fast, and accurate tool for searching the fetal cerebellum on ultrasound volumes.
Calibrating passive acoustic monitoring: Correcting humpback whale call detections for site-specific and time-dependent environmental characteristics
Authors: Helble Tyler A. , D'Spain Gerald L. , Campbell Greg S. , Hildebrand John A.
Published: October 2013

This paper demonstrates the importance of accounting for environmental effects on passive underwater acoustic monitoring results. The situation considered is the reduction in shipping off the California coast between 2008–2010 due to the recession and environmental legislation. The resulting variations in ocean noise change the probability of detecting marine mammal vocalizations. An acoustic model was used to calculate the time-varying probability of detecting humpback whale vocalizations under best-guess environmental conditions and varying noise. The uncorrected call counts suggest a diel pattern and an increase in calling over a two-year period; the corrected call counts show minimal evidence of these features.
Strong Premelting Effect in the Elastic Properties of hcp-Fe Under Inner-Core Conditions
Authors: Martorell Benjamí , Vočadlo Lidunka , Brodholt John , Wood Ian G.
Published: October 2013

On the Brink of Melting

The considerable pressures and temperatures of Earth's iron-rich inner core make it a challenge to compare measurements made in experimental systems with observed seismic data. Computational simulations of core materials may reconcile any apparent differences.

Martorell
et al.

(p.
466
, published online 10 October) used ab initio simulations to predict the elastic properties of iron at core pressures. As temperatures approached the melting point of pure iron, the material was predicted to weaken to the point that seismic waves would be slowed considerably. An inner core with a small percentage of light elements like oxygen and silicon near its melting temperature would correspond well with measured seismic velocities.
Draft Genome Sequence of
Bacillus
sp. Strain SB47, an Obligate Extreme Halophile Isolated from a Salt Pan of the Little Rann of Kutch, India
Authors: Pal Kamal Krishna , Dey Rinku , Thomas Manesh , Sherathia Dharmesh , Dalsania Trupti , Patel Ilaxi , Savsani Kinjal , Ghorai Sucheta , Vanpariya Sejal , Sukhadiya Bhoomika , Mandaliya Mona , Rupapara Rupal , Rawal Priya , Saxena Anil Kumar
Published: October 2013

Here, we report the 4.46-Mbp draft genome sequence of
Bacillus
sp. strain SB47, an extreme halophile isolated from a salt pan of the Little Rann of Kutch, India. Exploring the genome of this organism will facilitate the understanding and isolation of the gene(s) involved in its extreme osmotolerance.
Prolonged physical inactivity leads to a drop in toe skin temperature during local cold stress
Authors: Keramidas Michail E. , Kölegård Roger , Eiken Ola , Mekjavic Igor B.
Published: October 2013

The purpose was to examine the effects of a prolonged period of recumbency on the toe temperature responses during cold-water foot immersion. Ten healthy males underwent 35 days of horizontal bed rest. The right foot of the subjects was assigned as the experimental (EXP) foot. To prevent bed rest-induced vascular deconditioning in the left control foot (CON), a sub-atmospheric vascular pressure countermeasure regimen was applied on the left lower leg for 4 × 10 min every second day. On the first (BR-1) and the last (BR-35) day of the bed rest, subjects performed two 30 min foot immersion tests in 8 °C water, one with the EXP foot and the other with the CON foot. The tests were conducted in counter-balanced order and separated by at least a 15 min interval. At BR-35, the average skin temperature of the EXP foot was lower than at BR-1 (–0.8 °C; P = 0.05), a drop that was especially pronounced in the big toe (–1.6 °C; P = 0.05). In the CON foot, the average skin temperature decreased by 0.6 °C in BR-35, albeit the reduction was not statistically significant (P = 0.16). Moreover, the pressure countermeasure regimen ameliorated immersion-induced thermal discomfort for the CON foot (P = 0.05). Present findings suggest that severe physical inactivity exaggerates the drop in toe skin temperature during local cold stress, and thus might constitute a potential risk factor for local cold injury.
Photoelectric electron emission from a charged spherical particle: modified DuBridge theory
Authors: Misra Shikha , Sodha Mahendra Singh
Published: October 2013

Herein, the authors have derived expressions for the rate of emission and mean energy of photoelectrons emitted from the surface of a charged irradiated spherical particle, based on DuBridge theory, and compared the results with those obtained on the basis of Fowler’s theory. These expressions involve Wa, ν, and ξ = (hν – φ)/kT, in contrast to a single parameter, ξ, in Fowler’s theory. It is seen that there is significant difference between the prediction of the two theories on the dependence of rate of emission and corresponding mean energy of photoelectrons on the surface potential.
AN APPLICATION OF REGULAR CHAIN THEORY TO THE STUDY OF LIMIT CYCLES
Authors: CHEN CHANGBO , CORLESS ROBERT M. , MAZA MARC MORENO , YU PEI , ZHANG YIMING
Published: October 2013

In this paper, the theory of regular chains and a triangular decomposition method relying on modular computations are presented in order to symbolically solve multivariate polynomial systems. Based on the focus values for dynamic systems obtained by using normal form theory, this method is applied to compute the limit cycles bifurcating from Hopf critical points. In particular, a quadratic planar polynomial system is used to demonstrate the solving process and to show how to obtain center conditions. The modular computations based on regular chains are applied to a cubic planar polynomial system to show the computation efficiency of this method, and to obtain all real solutions of nine limit cycles around a singular point. To the authors' best knowledge, this is the first article to simultaneously provide a complete, rigorous proof for the existence of nine limit cycles in a cubic system and all real solutions for these limit cycles.
ROBUST BIFURCATION ANALYSIS OF SYSTEMS WITH DYNAMIC UNCERTAINTIES
Authors: INOUE MASAKI , IMURA JUN-ICHI , KASHIMA KENJI , AIHARA KAZUYUKI
Published: October 2013

In this paper, we propose in uncertain dynamical systems a novel method for identifying the region that includes all possible bifurcation boundaries. First, we formulate a robust bifurcation analysis problem for parameter-dependent differential equations with dynamic uncertainties. Next, to solve this problem, we give stability and instability conditions for the uncertain system. Finally, on the basis of these conditions, we propose a method for solving the robust bifurcation analysis problem.
ADAPTABILITY AND SENSITIVITY OF COMPLEX SYSTEMS
Authors: YE ZHI-CHENG , FAN QING-DUAN , HE QIN-BIN , LIU ZENG-RONG
Published: October 2013

Recently, the study on the dynamical behavior of complex dynamical systems has become a focal subject in the field of complexity. In particular, the system's adaptability and sensitivity have attracted increasing attention from various scientific communities. In this paper, we focus on some properties of complexity to gain a better understanding of it. Two descriptive mathematical definitions of attractors' adaptability and sensitivity are introduced from the viewpoint of dynamical systems. Then, these new descriptions are applied to analyze the adaptability and sensitivity of stable equilibrium points. In addition, a method is introduced for improving both the adaptability and sensitivity of a system with a stable equilibrium point.
High-Throughput Genomic Data in Systematics and Phylogenetics
Authors: Lemmon Emily Moriarty , Lemmon Alan R.
Published: October 2013

High-throughput genomic sequencing is rapidly changing the field of phylogenetics by decreasing the cost and increasing the quantity and rate of data collection by several orders of magnitude. This deluge of data is exerting tremendous pressure on downstream data-analysis methods providing new opportunities for method development. In this review, we present (a) recent advances in laboratory methods for collection of high-throughput phylogenetic data and (b) challenges and constraints for phylogenetic analysis of these data. We compare the merits of multiple laboratory approaches, compare methods of data analysis, and offer recommendations for the most promising protocols and data-analysis workflows currently available for phylogenetics. We also discuss several strategies for increasing accuracy, with an emphasis on locus selection and proper model choice.
Cognitive Ecology of Food Hoarding: The Evolution of Spatial Memory and the Hippocampus
Authors: Pravosudov Vladimir V. , Roth II Timothy C.
Published: October 2013

Many animals cache food when it is abundant and later rely in part on spatial memory to retrieve those caches. The importance of memory for cache recovery and fitness in food-caching species has been hypothesized to result in selection favoring enhanced spatial memory and an enlarged hippocampus, an area of the brain involved in spatial memory. This review aims to provide an overview of research investigating adaptive variation in memory, the hippocampus, and food hoarding; to identify the pitfalls of previous approaches; and to provide suggestions for future directions. Given the relatively low phylogenetic diversity of scatter-hoarding taxa, we advocate using a single-species, multipopulation approach to track evolutionary changes related to dependence on food caching for survival as a function of differences in the environment. We conclude that existing evidence strongly supports the hypothesis that spatial memory and its underlying neural mechanisms respond to selection pressures associated with scatter-hoarding food.
Interfacial Layers Between Regions of Different Turbulence Intensity
Authors: da Silva Carlos B. , Hunt Julian C.R. , Eames Ian , Westerweel Jerry
Published: October 2013

Recent developments in the physics and modeling of interfacial layers between regions with different turbulent intensities are reviewed. The flow dynamics across these layers governs exchanges of mass, momentum, energy, and scalars (e.g., temperature), which determine the growth, spreading, mixing, and reaction rates in many flows of engineering and natural interest. Results from several analytical and linearized models are reviewed. Particular attention is given to the case of turbulent/nonturbulent interfaces that exist at the edges of jets, wakes, mixing layers, and boundary layers. The geometry, dynamics, and scaling of these interfaces are reviewed, and future lines of research are suggested. The dynamics of passive and active scalars is also discussed, including the effects of stratification, turbulence level, and internal forcing. Finally, the modeling challenges for one-point closures and subgrid-scale models are briefly mentioned.
Aerodynamics of Heavy Vehicles
Authors: Choi Haecheon , Lee Jungil , Park Hyungmin
Published: October 2013

We present an overview of the aerodynamics of heavy vehicles, such as tractor-trailers, high-speed trains, and buses. We introduce three-dimensional flow structures around simplified model vehicles and heavy vehicles and discuss the flow-control devices used for drag reduction. Finally, we suggest important unsteady flow structures to investigate for the enhancement of aerodynamic performance and future directions for experimental and numerical approaches.
The Central Nervous System Sites Mediating the Orexigenic Actions of Ghrelin
Authors: Mason B.L. , Wang Q. , Zigman J.M.
Published: October 2013

The peptide hormone ghrelin is important for both homeostatic and hedonic eating behaviors, and its orexigenic actions occur mainly via binding to the only known ghrelin receptor, the growth hormone secretagogue receptor (GHSR). GHSRs are located in several distinct regions of the central nervous system. This review discusses those central nervous system sites that have been found to play critical roles in the orexigenic actions of ghrelin, including hypothalamic nuclei, the hippocampus, the amygdala, the caudal brain stem, and midbrain dopaminergic neurons. Hopefully, this review can be used as a stepping stone for the reader wanting to gain a clearer understanding of the central nervous system sites of direct ghrelin action on feeding behavior, and as inspiration for future studies to provide an even-more-detailed map of the neurocircuitry controlling eating and body weight.
Inkjet-Printed Organic Electronics: Operational Stability and Reliability Issues
Authors: Medeiros Maria C. R. , Martinez-Domingo Carme , Ramon Eloi , Negrier Aldric Trindade , Sowade Enrico , Mitra Kalayan Yoti , Baumann Reinhard R , McCulloch Ian , Carrabina Jordi , Gomes Henrique Leonel
Published: October 2013

The operational stability of all-inkjet printed transistors is reported. At room temperature the threshold voltage shifts following a stretched exponential with a relaxation time τ=1x103 s. Two distinct trap sites active in different temperature ranges, one at 200-250 K and other above 310 K cause the electrical instability. Both types of traps capture holes and can be fast neutralized by photogenerated electrons. Optically induced detrapping currents confirm the differences in trap signature. It is proposed, that the traps have a common physical origin related to water.
Time-frequency methods and voluntary ramped-frequency breathing: a powerful combination for exploration of human neurophysiological mechanisms
Authors: Stankovski Tomislav , Cooke William H. , Rudas László , Stefanovska Aneta , Eckberg Dwain L.
Published: October 2013

We experimentally altered the timing of respiratory motoneuron activity as a means to modulate and better understand otherwise hidden human central neural and hemodynamic oscillatory mechanisms. We recorded the electrocardiogram, finger photoplethysmographic arterial pressure, tidal carbon dioxide concentrations, and muscle sympathetic nerve activity in 13 healthy supine young men who gradually increased or decreased their breathing frequencies between 0.05 and 0.25 Hz over 9-min periods. We analyzed results with traditional time- and frequency-domain methods, and also with time-frequency methods (wavelet transform, wavelet phase coherence, and directional coupling). We determined statistical significance and identified frequency boundaries by comparing measurements with randomly generated surrogates. Our results support several major conclusions. First, respiration causally modulates both sympathetic (weakly) and vagal motoneuron (strongly) oscillations over a wide frequency range—one that extends well below the frequency of actual breaths. Second, breathing frequency broadly modulates vagal baroreflex gain, with peak gains registered in the low frequency range. Third, breathing frequency does not influence median levels of sympathetic or vagal activity over time. Fourth, phase relations between arterial pressure and sympathetic and vagal motoneurons are unaffected by breathing, and are therefore likely secondary to intrinsic responsiveness of these motoneurons to other synaptic inputs. Finally, breathing frequency does not affect phase coherence between diastolic pressure and muscle sympathetic oscillations, but it augments phase coherence between systolic pressure and R-R interval oscillations over a limited portion of the usual breathing frequency range. These results refine understanding of autonomic oscillatory processes and those physiological mechanisms known as the human respiratory gate.
Investigations into Deformation Characteristics during Open-Die Forging of SiCp Reinforced Aluminium Metal Matrix Composites
Authors: Verma Deep , Chandrasekhar P. , Singh S. , Kar S.
Published: October 2013

The deformation characteristics during open-die forging of silicon carbide particulate reinforced aluminium metal matrix composites (SiCp AMC) at cold conditions are investigated. The material was fabricated by liquid stir casting method in which preheated SiC particles were mixed with molten LM6 aluminium casting alloy and casted in the silicon mould. Finally, preforms obtained were machined in required dimensions. Two separate cases of deformation, that is, open-die forging of solid disc and solid rectangular preforms, were considered. Both upper bound theoretical analysis and experimental investigations were performed followed by finite element simulation using DEFORM, considering composite interfacial friction law, barreling of preform vertical sides, and inertia effects, that is, effect of die velocity on various deformation characteristics like effective stress, strain, strain rate, forging load, energy dissipations, and height reduction. Results have been presented graphically and critically investigated to evaluate the concurrence among theoretical, experimental, and finite element based computational findings.
Endoscopic Drainage of an Odontogenic Pterygoid Muscle Abscess
Authors: Varshney Rickul , Zawawi Faisal , Tewfik Marc A.
Published: October 2013

The infratemporal fossa (ITF) is a potential space bounded by bony structures that can be occupied by both benign and malignant tumors. It is also a potential area of abscess development, most commonly of dental origin. As with any abscess, the treatment of an ITF abscess is surgical drainage. We present a case of an ITF abscess involving the pterygoid muscles following dental extraction in a poorly controlled diabetic patient. The ITF was accessed with an endoscopic transseptal approach through the maxillary sinus to drain the abscess. This case of successful management supports the feasibility of the endoscopic approach in dealing with abscesses of the ITF.
Muscle Sensor Model Using Small Scale Optical Device for Pattern Recognitions
Authors: Tamee Kreangsak , Chaiwong Khomyuth , Yothapakdee Kriengsak , Yupapin Preecha P.
Published: October 2013

A new sensor system for measuring contraction and relaxation of muscles by using a PANDA ring resonator is proposed. The small scale optical device is designed and configured to perform the coupling effects between the changes in optical device phase shift and human facial muscle movement, which can be used to form the relationship between optical phase shift and muscle movement. By using the Optiwave and MATLAB programs, the results obtained have shown that the measurement of the contraction and relaxation of muscles can be obtained after the muscle movements, in which the unique pattern of individual muscle movement from facial expression can be established. The obtained simulation results, that is, interference signal patterns, can be used to form the various pattern recognitions, which are useful for the human machine interface and the human computer interface application and discussed in detail.
A Rare Case of a Pure Testicular Seminoma Presenting 7 Years after a Pineal Germinoma
Authors: Bhatty Usman Najeeb , Ashrafi Mohammed Hayat , Nicholson Caroline Mary , Haq Ahsanul
Published: October 2013

Pure testicular seminomas occurring in patients with previous intracranial germ cell tumours are extremely rare. We present such a case. A 37-year-old gentleman presented to urology after previously being treated for a pineal germinoma with steroids and radiotherapy. On routine followup, he described symptoms of a testicular seminoma. This was managed surgically with radical orchidectomy. We discuss the possible causes of such an association with a review of the literature.
Research of the Methylation Status of miR-124a Gene Promoter among Rheumatoid Arthritis Patients
Authors: Zhou Qiao , Long Li , Shi Guixiu , Zhang Jing , Wu Tong , Zhou Bin
Published: October 2013

Objective. To analyze the methylation status of miR-124a loci in synovial tissues of rheumatoid arthritis (RA) patients using methylation-specific polymerase chain reaction (MSP).Materials and Methods. DNA obtained from the frozen tissue of 7 RA samples, 6 osteoarthritis (OA) samples, and 3 healthy controls were undergoing bisulfite conversion and then analyzed for miR-124a promoter methylation using MSP assay.Results. miR-124-a1 and miR-124-a2 promoter methylation were both seen in 71.4% of RA samples compared to 16.7% of OA samples. miR-124-a3 promoter methylation was seen in 57.1% of RA samples and 0% of OA samples. All the three loci were unmethylated in 3 healthy controls.Conclusion. The methylation status of miR-124a seen in this study concurs with that reported in tumor cells, indicating epigenetic dysregulation constituents, a mechanism in the development of rheumatoid arthritis.
Malignant Mesothelioma after Household Exposure to Asbestos
Authors: Saba Raya , Aronu Godson Nnamdi , Bhatti Ravinder Pal , Mirrakhimov Aibek E. , Anusim Nwabundo , Barbaryan Aram , Kwatra Shawn G. , Iroegbu Nkemakolam
Published: October 2013

Malignant mesothelioma (MM) is an aggressive cancer that has been closely linked to asbestos exposure. Initially recognized as an occupational cancer in male workers, MM was later found to occur in their family members as well. We report the case of an 89-year-old female who presented with abdominal distention, pain, and findings consistent with malignant ascites. Family history was significant for fatal mesothelioma in her husband of 40 years, who was a worker at a tile factory. The diagnosis of MM was confirmed on pathologic examination of the omental core biopsy.
Development of Magnetic Nanoparticles for Cancer Gene Therapy: A Comprehensive Review
Authors: Mulens Vladimir , Morales María del Puerto , Barber Domingo F.
Published: October 2013

Since they were first proposed as nonviral transfection agents for their gene-carrying capacity, magnetic nanoparticles have been studied thoroughly, bothin vitroandin vivo. Great effort has been made to manufacture biocompatible magnetic nanoparticles for use in the theragnosis of cancer and other diseases. Here we survey recent advances in the study of magnetic nanoparticles, as well as the polymers and other coating layers currently available for gene therapy, their synthesis, and bioconjugation processes. In addition, we review several gene therapy models based on magnetic nanoparticles.