bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of ‘TRY’: an algorithm for neonatal continuous positive airways pressure in low-income settings
Authors: Crehan Caroline , Colbourn Tim , Heys Michelle , Molyneux Elizabeth
Published: March 2018

Background

Non-invasive respiratory support using bubble continuous positive airway pressure (bCPAP) is useful in treating babies with respiratory distress syndrome. Despite its proven clinical and cost-effectiveness, implementation is hampered by the inappropriate administration of bCPAP in low-resource settings. A clinical algorithm—‘TRY’ (based on Tone: good; Respiratory distress; Yes, heart rate above 100 beats/min)—has been developed to correctly identify which newborns would benefit most from bCPAP in a teaching hospital in Malawi.

Objective

To evaluate the reliability, sensitivity and specificity of TRY when employed by nurses in a Malawian district hospital.

Methods

Nursing staff in a Malawian district hospital baby unit were asked, over a 2-month period, to complete TRY assessments for every newly admitted baby with the following inclusion criteria: clinical evidence of respiratory distress and/or birth weight less than 1.3 kg. A visiting paediatrician, blinded to nurses’ assessments, concurrently assessed each baby, providing both a TRY assessment and a clinical decision regarding the need for CPAP administration. Inter-rater reliability was calculated comparing nursing and paediatrician TRY assessment outcomes. Sensitivity and specificity were estimated comparing nurse TRY assessments against the paediatrician’s clinical decision.

Results

Two hundred and eighty-seven infants were admitted during the study period; 145 (51%) of these met the inclusion criteria, and of these 57 (39%) received joint assessments. The inter-rater reliability was high (kappa 0.822). Sensitivity and specificity were 92% and 96%, respectively.

Conclusions

District hospital nurses, using the TRY-CPAP algorithm, reliably identified babies that might benefit from bCPAP and thus improved its effective implementation.
Pharmacokinetic study of isoniazid and pyrazinamide in children: impact of age and nutritional status
Authors: Dayal Rajeshwar , Singh Yatish , Agarwal Dipti , Kumar Manoj , Swaminathan Soumya , Ramachandran Geetha , Kumar Santosh , Narayan Shamrendra , Goyal Ankur , Kumar A K Hemant
Published: March 2018

Objectives

To evaluate pharmacokinetics of first-line antitubercular drugs, isoniazid (INH) and pyrazinamide (PZA), with revised WHO dosages and to assess its adequacy in relation to age and nutritional status.

Design

Observational study.

Setting

This study was conducted at Sarojini Naidu Medical College, Agra, and National Institute for Research in Tuberculosis, Chennai.

Patients

40 subjects diagnosed with tuberculosis were registered in the study and started on daily first-line antitubercular regimen based on the revised WHO guidelines.

Interventions

Blood samples were collected at 0, 2, 4, 6 and 8 hours from these subjects after 15 days of treatment for drug estimations.

Main outcome measure

The measurement of drug concentrations (maximum peak concentration (Cmax) and area under the time –concentration curve (AUC0–8 hours)) for INH and PZA. Appropriate statistical methods were used to evaluate the impact of age and nutritional status on pharmacokinetic variables.

Results

For INH, the difference in drug exposures in children <3 years (Cmax 3.18 µg/mL and AUC0–8 hours15.76 µg/mL hour) and children >3 years (Cmax3.05 µg/mL and AUC0–8 hours 14.37 µg/mL hour) was not significant (P=0.94, P=0.81, respectively). The drug levels in children with low body mass index (BMI) (Cmax3.08 µg/mL; AUC0–8 hours14.81 µg/mL hour) were also comparable with their normal counterparts (Cmax3.09 µg/mL, P=0.99; AUC0–8 hours 14.69 µg/mL hour, P=0.82). PZA drug exposures obtained in children less than 3 years (Cmax29.22 µg/mL, AUC0–8 hours 155.45 µg/mL hour) were significantly lower compared with drug levels in children above 3 years (Cmax 37.12 µg/mL, P=0.03; AUC 202.63 µg/mL hour, P value=0.01). Children with low BMI had significantly lower drug concentrations (Cmax 31.90 µg/mL, AUC0–8 hours167.64 µg/mL hour) when compared with normal counterparts (Cmax 37.60 µg/mL, P=0.02; AUC0–8 hours 208.77 µg/mL hour, P=0.01).

Conclusions

The revised WHO drug dosages were found to be adequate for INH with respect to age and nutritional status, whereas PZA showed significantly lower drug levels in children <3 years and in malnourished children.
Clinicians’ gaze behaviour in simulated paediatric emergencies
Authors: McNaughten Ben , Hart Caroline , Gallagher Stephen , Junk Carol , Coulter Patricia , Thompson Andrew , Bourke Thomas
Published: March 2018

Aim

Differences in the gaze behaviour of experts and novices are described in aviation and surgery. This study sought to describe the gaze behaviour of clinicians from different training backgrounds during a simulated paediatric emergency.

Methods

Clinicians from four clinical areas undertook a simulated emergency. Participants wore SMI (SensoMotoric Instruments) eye tracking glasses. We measured the fixation count and dwell time on predefined areas of interest and the time taken to key clinical interventions.

Results

Paediatric intensive care unit (PICU) consultants performed best and focused longer on the chest and airway. Paediatric consultants and trainees spent longer looking at the defibrillator and algorithm (51 180 ms and 50 551 ms, respectively) than the PICU and paediatric emergency medicine consultants.

Conclusions

This study is the first to describe differences in the gaze behaviour between experts and novices in a resuscitation. They mirror those described in aviation and surgery. Further research is needed to evaluate the potential use of eye tracking as an educational tool.
Improving routine outpatient monitoring for patients with sickle-cell disease on hydroxyurea
Authors: Ward Joel , Lewis Natasha , Tsitsikas Dimitris A
Published: March 2018

Hydroxyurea is the gold standard treatment for prevention of vaso-occlusive crises in patients with sickle-cell anaemia. It has a narrow therapeutic index and dangerous side effects including cytopenias. There is high variation in dose–response across the population. Therefore, a robust outpatient monitoring programme is crucial to ensure efficacy and safety of treatment. However, there has historically been difficulty engaging the target population in regular laboratory test monitoring programmes. This project aimed to ensure that all patients on hydroxyurea had routine blood tests at least once every 2 months which were reviewed and acted upon within the 3-year project life cycle. A specialist haematology nurse prescriber clinic service was introduced, first informally, and then formally to take blood tests, alter medication dosing, prescribe it and then write a clinic letter. The mean number of tests per patient per year rose from 0.21 at baseline to 9.05 after 2 years of the formal nurse prescriber clinic. This led to an associated increase in dose changes from 0.23 to 1.45 per patient per year. This improved the number of patients on the optimum dose of hydroxyurea. Furthermore, due to increased confidence in the outpatient monitoring, the total number of people being prescribed hydroxyurea increased from 26 to 42. Restriction of prescriptions to only those enrolled in the service has prevented unmonitored patients being at risk of the potential toxicities associated with doses that are too high. The introduction of a formal nurse-led clinic has improved the safety, efficacy and compliance and increased the number of patients on the gold standard preventative treatment for vaso-occlusive crises in sickle-cell anaemia.
From whom do physicians obtain consent for surgery?
Authors: Jarayedi Zahra , Asghari Fariba
Published: March 2018

Objective

To evaluate the knowledge and performance of surgical residents regarding the person from whom informed consent should be taken for surgery and from whom the consent is taken in practice.

Materials and methods

This study was done in 2013. The population of this study was all residents of urology, surgery, orthopaedic surgery and gynaecology of Tehran and Iran University of Medical Sciences. The study tool was a self-administered questionnaire, containing questions on their knowledge and performance regarding informed consent acquisition from patients with different conditions in terms of age, sex, marital status and their capacity to make treatment decisions.

Results

A total of 213 residents participated in the study (response rate=51.9%). The mean score of the participants’ knowledge was 72.95 out of 100. There was no significant correlation between the residents’ knowledge and performance. Regarding a competent married male patient, 98.2% of the residents knew that the person’s consent was enough, but only 63.6% obtained informed consent only from the patient. These percentages were 69% and 19.7% for a competent married female patient, respectively. For a competent single male patient, 90.9% of the residents were aware that the patient’s consent was enough, while only 40% of the residents obtained informed consent only from the patient. These percentages were 65.3% and 16% for a competent single female patient, respectively.

Conclusion

Despite the residents’ average knowledge of patient autonomy, this right is not observed for female patients, and their treatment is subject to consent acquisition from other family members.
The VITAL study and overall pooled analysis with the VIPS non-invasive stroke detection device
Authors: Kellner Christopher P , Sauvageau Eric , Snyder Kenneth V , Fargen Kyle M , Arthur Adam S , Turner Raymond D , Alexandrov Andrei V
Published: March 2018

Introduction

Effective triage of patients with emergent large vessel occlusion (ELVO) to endovascular therapy capable centers may decrease time to treatment and improve outcome for these patients. Here we performed a derivation study to evaluate the accuracy of a portable, non-invasive, and easy to use severe stroke detector.

Methods

The volumetric impedance phase shift spectroscopy (VIPS) device was used to assign a bioimpedance asymmetry score to 248 subjects across three cohorts, including 41 subjects presenting as acute stroke codes at a major comprehensive stroke center (CSC), 79 healthy volunteers, and 128 patients presenting to CSCs with a wide variety of brain pathology including additional stroke codes. Diagnostic parameters were calculated for the ability of the device to discern (1) severe stroke from minor stroke and (2) severe stroke from all other subjects. Patients with intracranial hardware were excluded from the analysis.

Results

The VIPS device was able to differentiate severe stroke from minor strokes with a sensitivity of 93% (95% CI 83 to 98), specificity of 92% (95% CI 75 to 99), and an area under the curve (AUC) of 0.93 (95% CI 0.85 to 0.97). The device was able to differentiate severe stroke from all other subjects with a sensitivity of 93% (95% CI 83 to 98), specificity of 87% (95% CI 81 to 92), and an AUC of 0.95 (95% CI 0.89 to 0.96).

Conclusion

The VIPS device is a portable, non-invasive, and easy to use tool that may aid in the detection of severe stroke, including ELVO, with a sensitivity of 93% and specificity of 92% in this derivation study. This device has the potential to improve the triage of patients suffering severe stroke.
Natural transmission of bovine viral diarrhoea virus‐1c from a persistently infected neonate lamb to naïve sheep and cattle
Authors: Evans Caitlin Alexandra , Hemmatzadeh Farhid , Reichel Michael P , Cockcroft Peter D
Published: March 2018

This study investigated the transmission of bovine viral diarrhoea virus (BVDV)‐1c from a persistently infected (PI) neonate lamb to naïve sheep and cattle using three treatment groups: four naïve ewes and their five lambs, which were copaddocked with the PI lamb; five steers, which were housed in a paddock adjacent to the PI lamb; and five steers, which had direct but limited exposure to the PI lamb. Serum samples were collected and tested for BVDV‐specific antibodies. Serum samples from the PI lamb, from day of birth to eight weeks of age, were tested for BVDV‐specific antibodies and antigen and submitted for quantitative PCR to determine the viral load present at each week of age. Only one lamb from the copaddocked group developed BVDV‐specific antibodies following comingling while all the steers in both the cattle treatment groups remained BVDV antibody negative. Quantitative PCR results from the PI lamb showed lower viral loads from day of birth to six weeks of age, compared with the results at seven and eight weeks of age. This may reflect maternal colostral BVDV antibody concentrations in the neonate lamb or other viral properties.
Changes in the understory plant community and ecosystem properties along a shrub density gradient
Authors: Crofts Anna L. , Drury Dennise O. , McLaren Jennie R.
Published: March 2018

Climate warming is projected to alter the vegetation community composition of arctic and alpine ecosystems including an increase in the relative abundance and cover of deciduous shrubs. This change in plant functional group dominance will likely alter tundra ecosystem structure and function. We conducted an observational study to quantify how the understory vegetation community and ecosystem properties varied along a shrub density and altitudinal gradient in a tundra alpine ecosystem in south-west Yukon. Although there was weak association between shrub density and species richness of understory community, there were large differences in functional group abundance between the different shrub densities; forb cover increased at lower elevations with higher shrub density at the expense of cryptogam and dwarf shrub cover. Litter mass, light interception, and soil carbon:nitrogen ratios all increased with shrub density. Sites with shrubs had higher summer soil temperatures, lower summer soil moisture, and lower percent soil nitrogen than the shrub-free site, although there was no difference in available nutrients among sites. This study presents findings from a nonmanipulated, model system where shrubification has been documented and suggests that direct and indirect effects of increasing shrub dominance are likely to affect the surrounding vegetation and abiotic environment controls.
A colorimetric method for the sequence-specific recognition of double-stranded DNA on the surface of a silver-coated glass slide
Authors: Guo Xiaoting , Wang Jing , Zhu Zhifang , Zhang Manjun , Li Haigang , Liu Jianmin , Ling Liansheng
Published: March 2018

In this study, a colorimetric method for sequence-specific recognition of double-stranded DNA (dsDNA) was established on the surface of a silver-coated glass slide. Oligo-1 was assembled on the surface of a silver-coated glass slide through an Ag–S bond, and Oligo-2 as reporter was used to bind with streptavidin-horseradish peroxidase (SA–HRP). They could bind with target dsDNA that was composed of Oligo-3 and Oligo-4 on the surface of a silver-coated glass slide through triplex formation. The bound HRP could be moved into the solution by DNase I and catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB). Therefore, the concentration of target dsDNA could be determined with the colour change of TMB. Under the optimum conditions, the absorbance was proportional to the concentration of target dsDNA over the range of 100 pmol/L to 2.0 nmol/L, with a detection limit of 13 pmol/L. In addition, this method showed good sequence selectivity, enabling it to be further developed for the detection of other polymerase chain reaction (PCR) products.
Palynomorphs from a lacustrine sequence provide evidence for palaeoenvironmental changes during the early Miocene in Central Anatolia, Turkey
Authors: Bi̇lteki̇n Demet
Published: March 2018

Pollen samples belonging to 54 plant taxa from 32 intervals in a 59 m thick lacustrine sequence in the Harami open pit lignite mine in Konya Province, Turkey, were studied to evaluate early Miocene (Aquitanian) changes in vegetation, climate, and environments in Central Anatolia. The regional vegetation consisted of forests, whose composition changed through time. An abundance of sub-tropical and warm-temperate, mainly deciduous trees in the lower part of Harami section indicates a warm and humid climate in the region during the earliest Miocene. A trend towards cooler and drier conditions, driven by a combination of regional and local factors, is reflected by the sequential establishment of two kinds of coniferous forests: a cedar (Cedrus) dominated forest in the middle part of the section, followed by a mixed cedar and pine (Pinus) forest in the upper part of the section. The high percentages of Cedrus in the middle and upper portions of the Harami section suggest that high-elevation coniferous forests were growing around mountain ranges. Although cedars have been a prominent part of the Anatolian flora since at least the early Miocene, in historical times their geographical range throughout the Mediterranean has been dramatically reduced by human activities.
Bowling ball representations of braid groups
Authors: Bigelow Stephen J.
Published: March 2018

In a remark in his seminal 1987 paper, Jones describes a way to define the Burau matrix of a positive braid using a metaphor of bowling a ball down a bowling alley with braided lanes. We extend this definition to allow multiple bowling balls to be bowled simultaneously. We obtain representations of the Iwahori–Hecke algebra and a cabled version of the Temperley–Lieb representation.
Mechanics of spacetime — A Solid Mechanics perspective on the theory of General Relativity
Authors: Tenev T. G. , Horstemeyer M. F.
Published: March 2018

We present an elastic constitutive model of gravity where we identify physical space with the mid-hypersurface of an elastic hyperplate called the “cosmic fabric” and spacetime with the fabric’s worldvolume. Using a Lagrangian formulation, we show that the fabric’s behavior as derived from Hooke’s Law is analogous to that of spacetime per the Field Equations of General Relativity (GR). The study is conducted in the limit of small strains, or analogously, in the limit of weak and nearly static gravitational fields. The Fabric’s Lagrangian outside of inclusions is shown to have the same form as the Einstein–Hilbert Lagrangian for free space. Properties of the fabric such as strain, stress, vibrations and elastic moduli are related to properties of gravity and space, such as the gravitational potential, gravitational acceleration, gravitational waves and the energy density of free space. By introducing a mechanical analogy of GR, we enable the application of Solid Mechanics tools to address problems in Cosmology.
COMPARISON OF PORE FRACTAL CHARACTERISTICS BETWEEN MARINE AND CONTINENTAL SHALES
Authors: LIU JUN , YAO YANBIN , LIU DAMENG , CAI YIDONG , CAI JIANCHAO
Published: March 2018

Fractal characterization offers a quantitative evaluation on the heterogeneity of pore structure which greatly affects gas adsorption and transportation in shales. To compare the fractal characteristics between marine and continental shales, nine samples from the Lower Silurian Longmaxi formation in the Sichuan basin and nine from the Middle Jurassic Dameigou formation in the Qaidam basin were collected. Reservoir properties and fractal dimensions were characterized for all the collected samples. In this study, fractal dimensions were originated from the Frenkel–Halsey–Hill (FHH) model with N[Formula: see text] adsorption data. Compared to continental shale, marine shale has greater values of quartz content, porosity, specific surface area and total pore volume but lower level of clay minerals content, permeability, average pore diameter and methane adsorption capacity. The quartz in marine shale is mostly associated with biogenic origin, while that in continental shale is mainly due to terrigenous debris. The N[Formula: see text] adsorption–desorption isotherms exhibit that marine shale has fewer inkbottle-shaped pores but more plate-like and slit-shaped pores than continental shale. Two fractal dimensions ([Formula: see text] and [Formula: see text] were obtained at [Formula: see text] of 0–0.5 and 0.5–1. The dimension [Formula: see text] is commonly greater than [Formula: see text], suggesting that larger pores (diameter [Formula: see text][Formula: see text]nm) have more complex structures than small pores (diameter [Formula: see text][Formula: see text]nm). The fractal dimensions (both [Formula: see text] and [Formula: see text]) positively correlate to clay minerals content, specific surface area and methane adsorption capacity, but have negative relationships with porosity, permeability and average pore diameter. The fractal dimensions increase proportionally with the increasing quartz content in marine shale but have no obvious correlation with that in continental shale. The dimension [Formula: see text] is correlative to the TOC content and permeability of marine shale at a similar degree with dimension [Formula: see text], while the dimension [Formula: see text] is more sensitive to those of continental shale than dimension [Formula: see text]. Compared with dimension [Formula: see text], for two shales, dimension [Formula: see text] is better associated with the content of clay minerals but has worse correlations with the specific surface area and average pore diameter.
A PERIPHERAL NERVE INJURY MODEL UTILIZING A SIMPLE TISSUE SPARING APPROACH TO THE RABBIT SCIATIC NERVE
Authors: Miller Andrew J. , Tulipan Jacob , Wang Mark , Beredjiklian Pedro , Fertala Andrzej , Rivlin Michael
Published: March 2018

Background & Aims: Peripheral nerve injury models require a reproducible surgical technique that provides a simple and extensile peripheral nerve exposure. We present a muscle sparing apprach to the sciatic nerve in a rabbit model. A combination of general anestheia, sedative and perioperative analgesics was given to minimize animal discomfort. Methods: A posterior lateral dissection of the rabbit hind leg was performed to expose the proximal sciatic nerve. This facilitated an extensile dissection of both the proximal and distal sciatic nerve. Results: The described dissection is atraumatic, bloodless, and yields minimal postoperative morbidity on the rabbit. All rabbits received standard postoperative care in compliance with all regulatory agencies. A full vetinarian staff was available to manage the animals postoperatively. Conclusion: We found that our technique is a reproducible and easy to perform surgical approach with basic surgical setup. Our animal model provides an opportunity to evaluate and study peripheral nerve injuries peripheral nerve injuries.
EVALUATING THE EFFECT OF VARIOUS MENISCAL ATTACHMENTS AND MATERIAL PROPERTIES ON FEMORAL BONE STRESS
Authors: Frazer Lance L. , Fischer Kenneth J.
Published: March 2018

In this paper, several finite element models of an equine stifle joint with varying meniscal properties and attachments are compared to understand the effects of meniscal attachment complexity and material property changes on bone stresses. We found that the complexity in the meniscal attachment is critical when evaluating tensile stresses in the bone. We also demonstrate that simplified material properties may be justified when the relationship between each material property and the desired output variables is well understood. The choice of the most efficient, and yet appropriate, meniscal modeling method depends on the goals of the model.
SENSITIVITIES OF ASIAN OPTIONS IN THE BLACK–SCHOLES MODEL
Authors: PIRJOL DAN , ZHU LINGJIONG
Published: March 2018

We propose analytical approximations for the sensitivities (Greeks) of the Asian options in the Black–Scholes model, following from a small maturity/volatility approximation for the option prices which has the exact short maturity limit, obtained using large deviations theory. Numerical tests demonstrate good agreement of the proposed approximation with alternative numerical simulation results for cases of practical interest. We also study the qualitative properties of Asian Greeks, including new results for Rho, the sensitivity with respect to changes in the risk-free rate, and Psi, the sensitivity with respect to the dividend yield. In particular, we show that the Rho of a fixed-strike Asian option and the Psi of a floating-strike Asian option can change sign.
Fault Detection of Broken Rotor Bar Using an Improved form of Hilbert–Huang Transform
Authors: Sabbaghian-Bidgoli F. , Poshtan J.
Published: March 2018

Signal processing is an integral part in signal-based fault diagnosis of rotary machinery. Signal processing converts the raw data into useful features to make the diagnostic operations. These features should be independent from the normal working conditions of the machine and the external noise. The extracted features should be sensitive only to faults in the machine. Therefore, applying more efficient processing techniques in order to achieve more useful features that bring faster and more accurate fault detection procedure has attracted the attention of researchers. This paper attempts to improve Hilbert–Huang transform (HHT) using wavelet packet transform (WPT) as a preprocessor instead of ensemble empirical mode decomposition (EEMD) to decompose the signal into narrow frequency bands and extract instantaneous frequency and compares the efficiency of the proposed method named “wavelet packet-based Hilbert transform (WPHT)” with the HHT in the extraction of broken rotor bar frequency components from vibration signals. These methods are tested on vibration signals of an electro-pump experimental setup. Moreover, this project applies wavelet packet de-noising to remove the noise of vibration signal before applying both methods mentioned and thereby achieves more useful features from vibration signals for the next stages of diagnosis procedure. The comparison of Hilbert transform amplitude spectrum and the values and numbers of detected instantaneous frequencies using HHT and WPHT techniques indicates the superiority of the WPHT technique to detect fault-related frequencies as an improved form of HHT.
Geometric Calibration Based on a Simple Phantom for Multi-Lens Microscopic CT
Authors: Luo Shouhua , Xu Haitao , Zheng Liang , Li Guang , Zhang Xiaobing , Shen Tao
Published: March 2018

In multi-lens microscopic cone-beam CT system, different resolutions can be achieved by tuning different objective lens with different magnifications, following the scan field of view (FOV) changed. By this multi-FOV/resolution acquisition strategy, many applications like truncation problem can be solved successfully. However, in order to achieve high-resolution image, the microscopic cone-beam CT system should comply with its geometrical restrictions accordingly, which are not only for that of conventional cone-beam system but also for that of multiple objective lens. Hence, compared with the existed cone-beam system calibration, a specific united calibration method is proposed in this paper. A set of geometrical parameters is presented, which can fully describe whole geometry of conventional cone-beam system as well as multi-lens. By taking use of projective data of circular trajectory of one single ball phantom, a cost function with the described arguments based on the projective lines of the phantom is built up. After solving the cost function, the calibration parameters can be determined optimally. The simulated and experimental results demonstrate that the proposed method shows significant improvements in robustness, precision and implementation.
On the Receding Contact Between a Homogeneous Elastic Layer and a Half-plane Substrate Coated with Functionally Graded Materials
Authors: Yan Jie , Mi Changwen
Published: March 2018

Mechanical contact threatens the integrity of engineering structures. In particular, receding contact is one of the primary causes that are responsible for the delamination of multilayered elastic structures. This paper aims to analyze the receding contact between a homogeneous elastic layer and a half-plane reinforced by a functionally graded coating. The multilayered structure is indented by a rigid stamp of convex profile. Governing equations and mixed boundary conditions of the double contact problem are converted into a pair of singular integral equations by Fourier integral transforms. The dual integral equations are numerically solved by Gauss–Chebyshev quadrature for the contact pressure and contact length at both interfaces of contact. Taking a circular punch as a case study, the developed algorithm is first validated against classical models available in the literature. Extensive parametric studies are subsequently performed to illustrate the effects of indentation load, geometry and material properties of individual components. Numerical results suggest the possibility of optimizing multilayered structures by the introduction of functionally graded materials (FGMs) as coatings or transitional layers.
Solution Bounds and Nearly Exact Solutions for 3D Nonlinear Problems of Large Deformation of Solids Using S-Fem
Authors: Wu S. W. , Li M. , Jiang C. , Liu G. R.
Published: March 2018

In this work, a three-dimensional (3D) nonlinear smoothed finite element method (S-FEM) solver is developed for large deformation problems. Node-based and face-based S-FEM using automatically generable four-noded tetrahedral elements (NS-FEM-Te4 and FS-FEM-Te4) are adopted to find the solution bounds in strain energy. The lower bound solutions are obtained using FEM-Te4 and FS-FEM-Te4, while the upper bound solutions are obtained using NS-FEM-Te4. A combined [Formula: see text]S-FEM-Te4 with a scaling factor [Formula: see text] that controls the combination is constructed to find nearly exact solutions for the nonlinear solids mechanics problems through adjusting [Formula: see text]. This is achieved using the property that a successive change of scaling factor [Formula: see text] can make the model transform from “overly-stiff” to “overly-soft”. Considering the properties of FS-FEM and NS-FEM, a selective FS/NS-FEM-TE4 is also used to solve 3D nonlinear large deformation problems, which produces a lower bound in strain energy. Hyperelastic Mooney–Rivlin and Ogden materials are both used in this study. Numerical examples reveal that S-FEM-Te4 is an effective method for obtaining solution bounds together with the standard FEM, and the FS-FEM-Te4, NS-FEM-Te4 and selective FS/NS-FEM-TE4 are robust with the high accuracy and computational efficiency for large deformation nonlinear problems.
Numerical Simulation of Water Entry with Improved SPH Method
Authors: Shao J. R. , Yang Y. , Gong H. F. , Liu M. B.
Published: March 2018

Water entry problems are very common in engineering and sciences. When objects move with relatively high speed, bubble cavities will be generated, and the behavior of moving objects will also be affected conversely. In this paper, the water entry problems are studied using smoothed particle hydrodynamics (SPH) method, which has special advantages in modeling free surfaces, moving interfaces. First, an improved fluid–solid interface treatment algorithm is presented, whose effectiveness is validated by a water entry of a buoyant cylinder. Then the water entry with different velocities and directions are researched. It is found that the velocities and angles of the moving objects will affect the movement of the object greatly, and the SPH model can give optimal predication of these corresponding conditions.
Quorum Sensing Driven Bacterial Swarm Optimization to Solve Practical Dynamic Power Ecological Emission Economic Dispatch
Authors: Vijay Raviprabakaran
Published: March 2018

This paper presents a Quorum Sensing Driven Bacterial Swarm Optimization (QBSO) to solve Dynamic Power Economic Ecological Emission Dispatch (DPEEED) problem with valve point loading effects. The exploration capability of the bacterial swarm is improved in this paper using quorum sensing and the anti-predatory activity. The performance of the proposed QBSO method is verified for optimality, practicability, convergence and robustness on a 5, 10-unit system. Furthermore, a practical south Indian 20-thermal generating units with recorded load demand profiles of three different weather situations. The numerical dispatch result indicates that the presented technique finds the minimized generating cost and consistently progresses the computational time. The presented technique outperforms the Bacterial Swarm Optimization (BSO) and the previous presented methods.
Modeling and Computation of Unsteady Cavitating Flows Involved Thermal Effects Using Partially Averaged Navier–Stokes Method
Authors: Sun Tiezhi , Zong Zhi , Wei Yingjie , Zhang Guiyong
Published: March 2018

The Partially Averaged Navier–Stokes (PANS) method is assessed with various values of the control parameters ([Formula: see text]–1.0, [Formula: see text]) by performing unsteady cavitating flows around a NACA0015 hydrofoil in a surrogate fluid of fluoroketone. Available experimental data of the cavity evolution and pressure are utilized to validate and evaluate the computational method. The results show that decreasing the control parameter [Formula: see text] can help to avoid the overestimations of the turbulence viscosity near the rear region of the cavity and can resolve more scales turbulence structure. The control parameter [Formula: see text] yields good predictions on cavitation shedding dynamics behavior and pressure distribution. Furthermore, the temperature around the hydrofoil undergoes a strong evolution that is contributed by the local evaporation and condensation processes. Interestingly, there are significant unsteady characteristics along the chordwise and spanwise directions of the hydrofoil. Finally, the thermal effect on cavitating flows is associated with the physical properties of fluid media. Evaporative cooling effects are more pronounced at high temperature and subsequently suppress the intensity of cavitation.
CYTOKERATIN PROFILES OF CANINE ANAL SAC AND HEPATOID GLAND NEOPLASMS
Authors: Stern Adam W. , Young Amanda J. , Pieper Jason B.
Published: March 2018

Ten adenocarcinomas of the apocrine gland of the anal sac and 11 hepatoid gland neoplasms were studied to determine the coordinate expression of cytokeratin 7 (CK7) and cytokeratin 14 (CK14) using commercially available antibodies. Hepatoid gland neoplasms included hepatoid gland adenomas, carcinomas and a single epithelioma. All 10 (100%) adenocarcinomas of the apocrine gland of the anal sac had CK7[Formula: see text]/CK14[Formula: see text] immunophenotype, whereas all 11 (100%) of hepatoid neoplasms expressed CK7[Formula: see text]/CK14[Formula: see text] immunophenotype. Hepatoid gland adenomas, carcinomas, and epithelioma could not be differentiated based on the cytokeratin immunophenotype. Hepatoid gland neoplasms could be differentiated from adenocarcinomas of the apocrine gland of the anal sac by differences in the CK7/CK14 immunophenotypes with a [Formula: see text]-[Formula: see text]. The results of this study provide further support for the use of coordinate expression of CK7/CK14 to differentiate apocrine gland adenocarcinomas of the anal sac (CK7[Formula: see text]/CK14[Formula: see text]) from hepatoid gland neoplasms (CK7[Formula: see text]/CK14[Formula: see text]).
Formulation of Low-Carbon City Development Roadmap: Technical Elements and Recommendations
Authors: ZHUANG Guiyang , ZHOU Zhen'ge
Published: March 2018

Promoting low-carbon development (LCD) is one of the basic requirements of building new-type urbanization with Chinese characteristics. Research on the formulation of low-carbon city development roadmap (hereinafter referred to as the “Roadmap”) is a necessity for systematic control of greenhouse gas (GHG) emission and the construction of low-carbon cities. Based on the actual conditions of cities as well as the regional and national development strategies, the Roadmap panoramically describes the strategic objectives, development plans, and key sectors' initiatives for the transformation of city development through planning techniques and solutions. Generally, the formulation of a low-carbon roadmap involves six steps: understanding the present situation of GHG emissions; analyzing the future emission scenarios; setting LCD targets; developing action plans for key sectors; assessing mitigation potential of low-carbon technologies/projects; and proposing measures for implementation. This paper, based on the practical experience in low-carbon city roadmap development and the needs of divisional management, establishes an analytical structure of GHG inventory for seven sectors, so as to link the key sectors for LCD, namely the seven major sectors for emissions reduction proposed by the Intergovernmental Panel on Climate Change (IPCC). Moreover, this paper integrates sectorial (industrial) low-carbon technology needs assessment (TNA) into the formulation of the Roadmap. It also provides several recommendations for better incorporating the two methods into the Roadmap: firstly, to strengthen the core function of GHG inventory by enhanced accounting quality and scientific and systematic analysis of the temporal and sectorial distribution of GHG emissions so as to serve the Roadmap formulation and decision-making. Secondly, to reinforce the derivative function of GHG inventory that serves the LCD planning, assessment, and decision-making by improving the quality and continuity of GHG inventory. Thirdly, to develop the derivative function of GHG inventory by integrating the improved GHG inventory and TNA into the formulation of the Roadmap.
Quarrying Companies Royal Engineers in World War II: contributions to military infrastructure within the UK and to Allied forces during the North African, Italian and NW Europe campaigns
Authors: Rose Edward P. F.
Published: March 2018

Eight Quarrying Companies Royal Engineers were raised during World War II, the first four in 1940. Unable to deploy to France as planned, these were used initially for bomb disposal, but from January 1941 companies 851 and 854 (succeeded in 1942 by 857) quarried stone for the construction of two military ports in western Scotland. In early to mid-1943, these companies were sent to support Allied forces in the North African Campaign and, from December 1943, the subsequent Italian Campaign. Other companies initially focused on ports and airfields associated with operations in the Atlantic: Company 853 quarried from 1941 to 1942 in Northern Ireland; Company 855 was deployed in 1941 to Poolewe in NW Scotland, before assignment in 1942–43 to Gibraltar; and companies 125 and 856 quarried from 1942 to 1943 on the Faroe Islands. Four companies were successively employed from 1942 to 1944 quarrying in Oxfordshire to aid the construction of a Central Ordnance Depot. Although three companies were operational in the Mediterranean region, the other five were united in 1944 to form a Quarry Group to support Allied operations in Normandy and the subsequent campaign across northern France, Belgium and into Germany. All eight received some geological guidance; all were disbanded before 1947.
The landslip-damaged Roman fort at Lympne in SE England
Authors: Bromhead Edward Nicholas
Published: March 2018

The late third century Roman fort at Lympne in Kent, one of a series known as the Saxon Shore forts, is one of the earliest substantial stone-built fortifications in SE England. It was sited on the lower slopes of an escarpment, the remnant of a former coastal slope, eroded principally into Early Cretaceous clays capped with sandy limestones. At this location, the escarpment rises to
c.
100 m above sea-level. Several episodes of landslip damage during the 17 centuries since its construction can be distinguished, based on evidence of various kinds: notably, the reconstruction of its original layout; the results of both geotechnical and archaeological site investigations; historical evidence; and analogy with sites and experience in adjacent lengths of the escarpment. The landslip damage manifests itself through the toppling and displacement of the curtain wall and projecting towers or bastions of the fort. The specific engineering geological interest arising from discoveries on site is the attribution of the damage to a small number of episodes of major movement rather than to creep; the magnitude of the movements associated with each episode; and the evidence as to their nature and date.
Long-term hypoxia uncouples Ca2+and eNOS in bradykinin-mediated pulmonary arterial relaxation
Authors: Blum-Johnston Carla , Thorpe Richard B. , Wee Chelsea , Opsahl Raechel , Romero Monica , Murray Samuel , Brunelle Alexander , Blood Quintin , Wilson Rachael , Blood Arlin B. , Zhang Lubo , Longo Lawrence D. , Pearce William J. , Wilson Sean M.
Published: March 2018

Bradykinin-induced activation of the pulmonary endothelium triggers a rise in intracellular Ca2+that activates nitric oxide (NO)-dependent vasorelaxation. Chronic hypoxia is commonly associated with increased pulmonary vascular tone, which can cause pulmonary hypertension in responsive individuals. In the present study, we tested the hypothesis that long-term high-altitude hypoxia (LTH) diminishes bradykinin-induced Ca2+signals and inhibits endothelial nitric oxide synthase (eNOS), prostacyclin (PGI2), and large-conductance K+(BKCa) channels in sheep, which are moderately responsive to LTH, resulting in decreased pulmonary arterial vasorelaxation. Pulmonary arteries were isolated from ewes kept near sea level (720 m) or at high altitude (3,801 m) for >100 days. Vessel force was measured with wire myography and endothelial intracellular Ca2+with confocal microscopy. eNOS was inhibited with 100 μM NG-nitro-l-arginine methyl ester (l-NAME), PGI2production was inhibited with 10 µM indomethacin that inhibits cyclooxygenase, and BKCachannels were blocked with 1 mM tetraethylammonium. Bradykinin-induced endothelial Ca2+signals increased following LTH, but bradykinin relaxation decreased. Furthermore, some vessels contracted in response to bradykinin after LTH. l-NAME sensitivity decreased, suggesting that eNOS dysfunction played a role in uncoupling Ca2+signals and bradykinin relaxation. The Ca2+ionophore A-23187 (10 µM) elicited an enhanced Ca2+response following LTH while relaxation was unchanged although l-NAME sensitivity increased. Additionally, BKCafunction decreased during bradykinin relaxation following LTH. Western analysis showed that BKCaα-subunit expression was increased by LTH while that for the β1subunit was unchanged. Overall, these results suggest that those even moderately responsive to LTH can have impaired endothelial function.
Glucose dilates renal afferent arterioles via glucose transporter-1
Authors: Zhang Jie , Jiang Shan , Wei Jin , Yip Kay-Pong , Wang Lei , Lai En Yin , Liu Ruisheng
Published: March 2018

Glomerular hyperfiltration occurs during the early stage of diabetes. An acute glucose infusion increases glomerular filtration rate. The involvement of tubuloglomerular feedback response and direct effect of glucose on the afferent arterioles (Af-Arts) have been suggested. However, the signaling pathways to trigger Af-Art dilatation have not been fully identified. Therefore, in the present study we tested our hypothesis that an increase in glucose concentration enhances endothelial nitric oxide synthesis activity and dilates the Af-Arts via glucose transporter-1 (GLUT1) using isolated mouse Af-Arts with perfusion. We isolated and microperfused the Af-Arts from nondiabetic C57BL/6 mice. The Af-Arts were preconstricted with norepinephrine (1 µM). When we switched the d-glucose concentration from low (5 mM) to high (30 mM) in the perfusate, the preconstricted Af-Arts significantly dilated by 37.8 ± 7.1%, but L-glucose did not trigger the dilation. GLUT1 mRNA was identified in microdisserted Af-Arts measured by RT-PCR. Changes in nitric oxide (NO) production in Af-Art were also measured using fluorescent probe when ambient glucose concentration was increased. When the d-glucose concentration was switched from 5 to 30 mM, NO generation in Af-Art was significantly increased by 19.2 ± 6.2% (84.7 ± 4.1 to 101.0 ± 9.3 U/min). l-Glucose had no effect on the NO generation. The GLUT1-selective antagonist 4-[({[4-(1,1-Dimethylethyl)phenyl]sulfonyl}amino)methyl]- N-3-pyridinylbenzamide and the nitric oxide synthase inhibitor NG-nitro-l-arginine methyl ester blocked the high glucose-induced NO generation and vasodilation. In conclusion, we demonstrated that an increase in glucose concentration dilates the Af-Art by stimulation of the endothelium-derived NO production mediated by GLUT1.
Analytical Study on the Influence of Parasitic Elements in a Memristor
Authors: Chandía Kristopher J. , Bologna Mauro , Tellini Bernardo
Published: March 2018

We study a memristive circuit with included parasitic elements, such as capacitance and inductance. In the multiple-scale scheme, we analytically show how the parasitic elements affect the voltage and the current. Finally, we provide an analytical expression for the intersection point coordinates, through which we discuss the functional behavior of the pinched hysteresis loop versus the operating frequency and the parasitic elements.
Multiple Scattering of P1 Waves by Arbitrarily Arranged Cavities in Saturated Soils
Authors: Sun Miaomiao , Fang Huajian , Zheng Xiaokang , Zhang Ru , Zhang Shimin , Zhou Lianying
Published: March 2018

Based on Biot’s saturated soil wave theory, using wave function expansion method, theoretical solutions of multiple scattering of plain P1 waves are achieved by rows of cavities as barrier with arbitrarily arranged cavities in saturated soil. Undetermined complex coefficients after wave function expansion are obtained by cavities‐soil stress and displacement free boundary conditions. Numerical examples are used to investigate variation of dimensionless displacement amplitude at the back and force of cavities barrier under P1 wave incident, and it is also discussed that the main parameters influenced isolation effect such as scattering orders, separation of cavities, distances between cavity rows, numbers of cavities, and arrangement of barriers. The results clearly demonstrate optimum design proposals with rows of cavities: with the multiple scattering order increases, the displacement amplitude tends to converge and the deviation caused by subsequent scattering cannot be neglected; it will obtain higher calculation accuracy when the order of scattering is truncated at m = 4; it is considered to select 2.5 ≤ sp/as ≤ 3.0 and 2.5 ≤ h/as ≤ 3.5, while designing cavity spacing and row‐distance, respectively. The isolation properties of elastic waves with rectangular arrangement (counterpoint) are weaker than that with hexagonal arrangement (counterchanged) when the row‐distance of barrier is uniform.