bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Oil Recovery and Carbonate Rock’s Properties Alterations by CO2 Miscible Flooding
Authors: Han Jinju , Seo Youngjin , Kim Juhyun , Han Sunlee , Lee Youngsoo
Published: September 2018

This present study indicates experimental investigation about the impact of CO2 flooding on oil recovery and rock’s properties alteration in carbonate reservoir under the miscible condition. In order to compare the effect to initial pore characteristic, two type of carbonate rock was used; an Edward white represents homogeneous mainly consisted micropore, whereas an Indiana limestone represented heterogeneous mainly consisted macropore in this study. Under the miscible condition (9.65 MPa and 40°C), five pore volume of CO2 were injected into oil-wet carbonate rock, which was fully saturated with oil and connate water. After CO2 flooding, several analyses for each sample conducted to investigate oil recovery and rock properties change in porosity, permeability, and pore structure by chemical and physical reaction between CO2, water, and carbonate mineral before and after CO2 flooding by using core analysis, MICP, SEM, ICP, and X-ray CT techniques. From the results of oil recovery, it was more effective and larger in Edward white than in Indiana limestone. Because homogeneous characteristic with a large ratio of low permeable micropore in Edward white contributed to occur long reaction time between oil and CO2 for enough miscibility as well as to displace stably oil by CO2. Conversely, heterogeneous pore structure mainly consisted of high permeable conduit (macropore) in Indiana limestone has brought ineffective and low oil production. From the analysis of rock’s properties alteration, we found that, for the homogeneous sample, dissolution dominantly changed pore structure and became better flow path by improving permeability and reducing tortuosity. While plugging by precipitation of mineral particles was not critically affected rock’ properties, despite the sample mainly consisted small pores. In the case of the heterogeneous sample, both dissolution and precipitation critically affected change of rock’s properties and pore structure. In particular, superior precipitation in complex pore network seriously damaged flow path and change of rock’s properties. The largest porosity change markedly appeared in inlet section because of exposing rock surface from fresh CO2 during a long time. In conclusion, it shows that CO2 miscible flooding in carbonate reservoirs significantly affected to alteration of rock’s properties such as porosity, permeability, tortuosity, and pore connectivity, in particular in heterogeneous system compared with in homogeneous system. These experimental results can be useful to characterize carbonate rock as well as to study rock properties alteration on CO2 EOR and CCS processes.
Influence of the Discount Rate in the Economic Analysis of a Floating Offshore Wind Farm in the Galician Region of the European Atlantic Area
Authors: Castro-Santos Laura , Filgueira-Vizoso Almudena , Lamas-Galdo Isabel , Álvarez-Feal Carlos , Carral-Couce Luis
Published: September 2018

The aim of this study is to evaluate the influence of the discount rate in some economic parameters which are relevant to study a floating offshore wind farm: the Net Present Value (NPV), the Levelized Cost Of Energy (LCOE) and the Discounted PayBack Period (DPBP). For this purpose, several maps have been created considering a particular location of the Atlantic Area: the Galician coast (North-West of Spain); and four alternatives, depending on the type of electric tariff or the type of discount rate. Results indicate the importance that the discount rate has in the economic feasibility of a floating offshore wind farm. In this context, the NPV is reduced when the discount rate is increased, the LCOE is reduced when the discount rate is increased, the IRR does not vary depending on the discount rate and the DPBP is increased with the discount rate. The discount rate can vary depending on the sector, the investor or the country where the floating offshore wind farm is installed. The motivation of this paper is to analyze the influence of one of the most important economic parameters in a floating offshore wind farm: the discount rate. Therefore, this type of analysis is very interesting in order to study its influence on the economic results, which are very important to take decisions for investors of the offshore renewable energy industry.
Effect of Human Factor on OCTG Collapse Testing
Authors: Minescu Mihail , Teodoriu Catalin , Caltaru Mihaela , Badicioiu Marius
Published: September 2018

Well construction relies on metal pipes called casing to maintain its integrity during the life of the well. From surface to the target depths the inserted casings are used to prevent well collapse, hence being exposed to external pressure loads. Also the casing in place must hold the internal pressure during well operations, which is called burst resistance. During the past decades the manufacturing process of casing and tubing has been dramatically improved, but their testing has suffer very little changes. It is known to date that API calculation of collapse resistance is very conservative, most of the modern pipe mills being able to deliver pipes with higher collapse pressure than API calculated values. The paper will describe the actual testing procedure of collapse testing of pipes and critically discuss about the human error that is introduced during these measurements. The results shows that only through high quality laboratory standards, such errors can be mitigated, while automation must be carefully considered.
Short-Term Extreme Motions of a Spar Floating Wind Turbine Estimated Through a 1:30 At-Sea Experiment
Authors: Ruzzo Carlo , Saha Nilanjan , Arena Felice
Published: September 2018

The present paper deals with the estimation of the short-term extreme motions of a spar floating wind turbine in parked rotor conditions, through a 1:30 at-sea experiment, carried out at the Natural Ocean Engineering Laboratory (NOEL) of Reggio Calabria (Italy). Thanks to some favorable local environmental conditions of the site, several wind-generated sea states with relatively low significant wave height (Hs < 0.50 m) have been collected during the experiment. These sea states are scale models of ocean storms, which are relevant hydrodynamic design conditions for the spar platform. The 30-minutes extreme values of the model structure motions have been estimated for all the six degrees of freedom, using the Weibull Tail Method (WTM), and the results obtained are presented in the paper. Such estimations are 1:30 scale models of the 3-hours extreme values of the spar motions in parked rotor conditions and may be directly used for design purposes.
Equivalent Storm Model for Long-Term Statistics of Sea Storms Off Norway
Authors: Laface Valentina , Magnusson Anne Karin , Bitner-Gregersen Elzbieta M. , Reistad Magnar , Romolo Alessandra , Arena Felice
Published: September 2018

The paper deals with long-term analysis of ocean storms off Norway. Sixty years of wave model time series are considered for the analysis. The input data provide spectral characteristics of both wind and swell seas. The availability of global and partitioned significant wave heights enables the possibility of investigating how swell seas influence the storm shape in terms of growing and decay stages and on how this aspect affects the long-term estimates. The analysis is conducted by means of equivalent storm approach which consists of substituting the sequence of actual storms at a given site with a sequence of equivalent storms whose shape is fixed (such as triangular, power or exponential) and then calculating return periods of storm with given characteristics via analytical solutions derived on the basis of storm shape assumed. This is possible due to statistical equivalence between actual and equivalent storms which in turn leads to the equality of wave risk between actual and equivalent storm sequences at a given site. The equivalent storm associated with an actual one is defined by means of two parameters, related to the storm intensity and duration. The equivalent storm intensity is given by the maximum significant wave height in the actual storm history, while the duration is determined via an iterative procedure. In this paper the exponential shape is considered which is referred as equivalent exponential (EES) storm model. Some aspects related with the storm shape and its influence on return values estimate via EES model are investigated. Further, a sensitivity analysis of EES model to the storm threshold is proposed.
Calibration of a Time-Domain Numerical Hydrodynamic Model for Mooring Analysis of a Semi-Submersible
Authors: Fonseca Nuno , Stansberg Carl Trygve
Published: September 2018

The paper presents calibration of a time domain numerical model for the motions of the Exwave Semi in high seastates with current. The time domain equations of motion combine linear radiation, linear diffraction and second order wave drift forces, based on MULDIF diffraction code, with nonlinear forces from quadratic damping and from the mooring system. Calibration is performed by comparing simulations with model test data and adjusting hydrodynamic coefficients known to be affected by uncertainty. These include wave drift force coefficients, damping and added mass coefficients. Correction of the drift coefficients is based on empirical quadratic transfer functions (QTFs) identified from the test data by a nonlinear data analysis technique known as “cross-bi-spectral analysis”.

Initial “uncalibrated” numerical models are based on input from the mooring, vessel mass, MULDIF hydrodynamic analysis, decay tests and current coefficients. They need adjustments for surge and sway. Empirical drift coefficients, natural periods and damping coefficients are then adjusted by matching low frequency surge and sway spectra. Wave-frequency coefficients need no adjustment. Low frequency wave drift forces, damping and added mass need increase in high sea states, in particular with current. Final motion simulations show 30%–40% underestimation in initial simulations, while final calibrated simulations are close to the measured records.
Response of the U-OWC Prototype Installed in the Civitavecchia Harbour
Authors: Arena Felice , Romolo Alessandra , Malara Giovanni , Fiamma Vincenzo , Laface Valentina
Published: September 2018

The Resonant Wave Energy Converter 3 (REWEC3) is a wave energy converter belonging to the family of Oscillating Water Columns (OWCs). It comprises an oscillating water column and an air pocket connected to a turbine, as in the traditional OWCs. In addition, it has a small vertical U-shaped duct connecting the water column to the open wave field. Because of this particular geometrical configuration, it is also known as U-Oscillating Water Column (U-OWC). The first full-scale prototype was constructed in the Port of Civitavecchia (Rome, Italy), in the context of a major port enlargement. This paper shows some results of the monitoring activity pursued on one U-OWC chamber equipped with sensors measuring water and air pressures. The activity has been conducted for about 1 year. The energetic performance of the plant is investigated in the paper, via the estimation of the capture width ratio.
A Novel Algorithm for Quasi Real-Time Matching of Bathymetric Data
Authors: Al-Rawi Mohammed , Sebastien Tauvry , Isasi Alberto , Galdran Adrian , Rodriguez Jonathan , Elmgren Fredrik , Bastos Joaquim , Pinto Marc
Published: September 2018

Matching two regions represented in bathymetric data that have some form of geographical overlapping is an important and challenging aspect in underwater mapping. It is important because of the possible error in estimating the geographical location of each point underwater. It is challenging due to the size of the acquired bathymetric data points. The matching could also play a vital role in the registration of underwater images and/or maps fusion, if both bathymetric and intensity scans are considered. Compared to the exhaustive search that requires polynomial time, O(n2), an efficient bathymetric matching algorithm is proposed in this work that finds several match-points in linear time, requiring thus O(n) computations. The paper thus presents a new algorithm that allows to compile the bathymetric data of the common areas of two submarine areas that have been sampled in underwater missions.
Treatment of Dextran Sulfate Sodium-Induced Colitis with Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Inhibitor MI-2 Is Associated with Restoration of Gut Immune Function and the Microbiota
Authors: Lee Kyung Won , Kim Minseok , Lee Chang Hoon
Published: September 2018

Disruption of the healthy intestinal microbiome and homeostasis of the intestinal immune system, which are closely interactive, are two key factors for ulcerative colitis. Here, we show that MI-2, a selective inhibitor of mucosa-associated lymphoid tissue lymphoma translocation-1 (MALT1), alleviated excessive inflammatory responses and was associated with restoration of healthy intestinal microbiome in mice suffering from dextran sulfate sodium (DSS)-induced colitis.
Improved Tolerability of a Salmonella enterica Serovar Typhimurium Live-Attenuated Vaccine Strain Achieved by Balancing Inflammatory Potential with Immunogenicity
Authors: Higginson Ellen E. , Ramachandran Girish , Panda Aruna , Shipley Steven T. , Kriel Edwin H. , DeTolla Louis J. , Lipsky Michael , Perkins Darren J. , Salerno-Goncalves Rosangela , Sztein Marcelo B. , Pasetti Marcela F. , Levine Myron M. , Tennant Sharon M.
Published: September 2018

A notable proportion of
Salmonella
-associated gastroenteritis in the United States is attributed to
Salmonella enterica
serovar Typhimurium. We have previously shown that live-attenuated
S
.
Role of Acetyltransferase PG1842 in Gingipain Biogenesis in Porphyromonas gingivalis
Authors: Mishra Arunima , Roy Francis , Dou Yuetan , Zhang Kangling , Tang Hui , Fletcher Hansel M.
Published: September 2018

Gingipain proteases are key virulence factors secreted by
Porphyromonas gingivalis
that cause periodontal tissue damage and the degradation of the host immune system proteins. Gingipains are translated as an inactive zymogen to restrict intracellular proteolytic activity before secretion. Posttranslational processing converts the inactive proenzyme to a catalytically active protease. Gingipain biogenesis, including its secretion and activation, is a complex process which is still not fully understood. One recent study identified acetylated lysine residues in the three gingipains RgpA, RgpB, and Kgp, thus indicating a role for acetylation in gingipain biogenesis. Here, we show that the acetyltransferases VimA and PG1842 can acetylate the pro-RgpB gingipain species. These findings further indicate that acetylation is a potential mechanism in the gingipain activation/maturation pathway in
P. gingivalis
.
Lysosomal Proteases Are a Determinant of Coronavirus Tropism
Authors: Zheng Yuan , Shang Jian , Yang Yang , Liu Chang , Wan Yushun , Geng Qibin , Wang Michelle , Baric Ralph , Li Fang
Published: September 2018

Coronaviruses are capable of colonizing new species, as evidenced by the recent emergence of SARS and MERS coronaviruses; they can also infect multiple tissues in the same species. Lysosomal proteases play critical roles in coronavirus entry by cleaving coronavirus surface spike proteins and activating the fusion of host and viral membranes; they also play critical roles in cell physiology by processing cellular products. How do different lysosomal protease activities from different cells impact coronavirus entry? Here, we controlled the contributions from known factors that function in coronavirus entry so that lysosomal protease activities became the only or the main determinant of coronavirus entry. Using pseudovirus entry, cell-cell fusion, and biochemical assays, we showed that lysosomal proteases from bat cells activate coronavirus spike-mediated membrane fusion more efficiently than their counterparts from human cells. Our study provides the first direct evidence supporting lysosomal proteases as a determinant of the species and tissue tropisms of coronaviruses.
Virulent Pseudorabies Virus Infection Induces a Specific and Lethal Systemic Inflammatory Response in Mice
Authors: Laval K. , Vernejoul J. B. , Van Cleemput J. , Koyuncu O. O. , Enquist L. W.
Published: September 2018

Pseudorabies virus (PRV) is an alphaherpesvirus related to human pathogens such as herpes simplex virus 1 and varicella-zoster virus (VZV). The natural host of PRV is the swine, but it can infect most mammals. In susceptible animals other than pigs, PRV infection always causes a characteristic lethal pruritus known as the “mad itch.” The role of the immune response in the clinical outcome of PRV infection is still poorly understood. Here, we show that a systemic host inflammatory response is responsible for the severe pruritus and acute death of mice infected with virulent PRV-Becker but not mice infected with attenuated strain PRV-Bartha. In addition, we identified IL-6 and G-CSF as two main cytokines that play crucial roles in the regulation of this process. Our findings give new insights into neuroinflammatory diseases and strengthen further the similarities between VZV and PRV infections at the level of innate immunity.
Widespread Antibiotic, Biocide, and Metal Resistance in Microbial Communities Inhabiting a Municipal Waste Environment and Anthropogenically Impacted River
Authors: Collins-Fairclough Aneisha M. , Co Rebecca , Ellis Melessa C. , Hug Laura A.
Published: September 2018

Landfill leachate is a persistent contamination threat for terrestrial waters. Microbial metabolism in landfills transforms contaminants and contributes to greenhouse gas emissions. A better understanding of landfill-associated microbial communities will inform bioremediation of solid waste environments and improve pathogen monitoring. We leveraged shotgun metagenomics to investigate the microbial communities of the Riverton City dump and the adjoining Duhaney River near Kingston City, Jamaica. We identified no overlap between the microbial communities inhabiting the Riverton City dump leachate and the Duhaney River. Both communities are predicted to degrade aromatic compounds, which are ubiquitous environmental pollutants. Adversely, microbes in both environments are predicted to withstand widely used antibiotics, antiseptics, and metal contamination. The absence of evidence for microbial transfer from the leachate to the river is encouraging; however, the Duhaney River contained several organisms with predicted pathogenic lifestyles, indicating that the river represents a human health risk regardless of impact from the dump.
The
Toxoplasma gondii
Active Serine Hydrolase 4 Regulates Parasite Division and Intravacuolar Parasite Architecture
Authors: Foe Ian T. , Onguka Ouma , Amberg-Johnson Katherine , Garner Rikki M. , Amara Neri , Beatty Wandy , Yeh Ellen , Bogyo Matthew
Published: September 2018

This work defines the function of an enzyme in the obligate intracellular parasite
Toxoplasma gondii
. We show that this previously uncharacterized enzyme is critical for aspects of cellular division by the parasite and that loss of this enzyme leads to parasites with cell division defects and which also are disorganized inside their vacuoles. This leads to defects in the ability of the parasite to disseminate from the site of an infection and may have a significant impact on the parasite's overall infectivity of a host organism.
Medical Assistance in Dying at a paediatric hospital
Authors: DeMichelis Carey , Zlotnik Shaul Randi , Rapoport Adam
Published: September 2018

This article explores the ethical challenges of providing Medical Assistance in Dying (MAID) in a paediatric setting. More specifically, we focus on the theoretical questions that came to light when we were asked to develop a policy for responding to MAID requests at our tertiary paediatric institution. We illuminate a central point of conceptual confusion about the nature of MAID that emerges at the level of practice, and explore the various entailments for clinicians and patients that would flow from different understandings. Finally, we consider the ethical challenges of building policy on what is still an extremely controversial social practice. While MAID is currently available to capable patients in Canada who are 18 years or older—a small but important subsection of the population our hospital serves—we write our policy with an eye to the near future when capable young people may gain access to MAID. We propose that an opportunity exists for MAID-providing institutions to reduce social stigma surrounding this practice, but not without potentially serious consequences for practitioners and institutions themselves. Thus, this paper is intended as a road map through the still-emerging legal and ethical landscape of paediatric MAID. We offer a view of the roads taken and considered along the way, and our justifications for travelling the paths we chose. By providing a record of our in-progress thinking, we hope to stimulate wider discussion about the issues and questions encountered in this work.
Temperature and serine phosphorylation regulate glycerol-3-phosphate dehydrogenase in skeletal muscle of hibernating Richardson’s ground squirrels
Authors: Ruberto Anthony A. , Logan Samantha M. , Storey Kenneth B.
Published: September 2018

Glycerol-3-phosphate dehydrogenase (G3PDH) bridges carbohydrate and lipid metabolism by interconverting glycerol-3-phosphate (G3P) and dihydroxyacetone phosphate (DHAP). This reversible reaction converts G3P derived from triglyceride hydrolysis to DHAP that can then enter glycolysis or gluconeogenesis and, in the reverse reaction, makes G3P for use in triglyceride biosynthesis. Small hibernating mammals rely almost exclusively on triglyceride reserves as their fuel for energy production during torpor and the recovery of glycerol after lipolysis is an important source of carbohydrate over the nonfeeding winter months. G3PDH (∼37 kDa) was purified from skeletal muscle of euthermic and hibernating Richardson’s ground squirrels (Urocitellus richardsonii) using three column chromatography steps. Analysis of enzyme kinetic properties revealed that G3PDH from hibernator muscle had higher affinities for G3P and NAD at low (5 °C) assay temperature compared with high (21 or 37 °C) and a greater stability in the presence of denaturing agents (urea, guanidine hydrochloride) or high temperature (50 °C). Immunoblotting showed that hibernator muscle G3PDH had a higher phosphoserine content than the enzyme from euthermic controls and incubation studies showed that enzyme affinity for G3P changed significantly by stimulating endogenous protein kinases or phosphatases. Overall, this study suggests that the properties of ground squirrel muscle G3PDH are modulated by temperature and post-translational phosphorylation to alter enzyme function under euthermic versus hibernating states.
Molecular design on a new family of azaoxaadamantane cage compounds as potential high-energy density compounds
Authors: Pan Yong , Zhu Weihua , Xiao Heming
Published: September 2018

A new family of azaoxaadamantane cage compounds were firstly designed by introducing the oxygen atom into hexanitrohexaazaoxaadmantane (HNHAA) to replace the N–NO2 group. Their properties including heats of formation (HOFs), detonation properties, strain energies, thermal stability, and sensitivity were extensively studied by using density functional theory. All of the title compounds exhibit surprisingly high density (ρ > 2.01 g/cm3) and excellent detonation properties (detonation velocity (D) > 9.29 km/s and detonation pressure (P) > 40.80 GPa). In particular, B (4,8,9,10-tetraazadioxaadamantane) and C (6,8,9,10-tetraazadioxaadamantane) have a remarkably high D and P values (9.70 km/s and 44.45 GPa, respectively), which are higher than that of HNHAA or CL-20. All of the title compound have higher thermal stability and lower sensitivity (h50 > 19.58 cm) compared with the parent compound HNHAA. Three triazatrioxaadamantane cage compounds, D (6,8,9-triazatrioxaadamantane), E (6,8,10-triazatrioxaadamantane), and F (8,9,10-triazatrioxaadamantane), are expected to be relatively insensitive explosives. All of the title compounds exhibit a combination of high denotation properties, good thermal stability, and low insensitivity.
Paleomagnetism of the Mn wad deposit at Niimi hot springs, Hokkaido, Japan
Authors: Kawasaki Kazuo
Published: September 2018

The Niimi hot springs is located at the foot of Mt. Shyakunage in the active Niseko volcanic area, Hokkaido, Japan. The manganese (Mn) wad deposit was precipitated from the hot spring water by biomineralization processes. However, no precise direct age dates for the diagenesis of such Mn oxides have been reported. Here is reported the first paleomagnetic application to date Mn oxides on 144 disseminated Mn wad and 42 pyroclastic clay specimens. The Mn wad specimens were collected at 14 levels between ∼5.5 and ∼62 cm in thickness on a three-dimensional grid pattern, and the clay specimens were collected at seven levels between 85 and 118 cm in thickness. Alternating field step demagnetization isolates either one or two stable characteristic remanent magnetization (ChRM) components in the Mn wad specimens. The lower coercivity component resides in pseudosingle domain titanomagnetite and shows clustered ChRM directions at each sampling level. Conversely, the higher coercivity component resides in single domain titanomagnetite and shows more random directions. The higher coercivity component is likely carried by pyroclastic fragments that landed on the site. The remanent directions of the clay specimens reside in multidomain magnetite, are less stable, and show a scattered distribution. When the observed ChRM directions of the Mn wad specimens are compared with the paleosecular variation record from Lake Biwa in Japan, the Mn wad deposition records the secular variation and appears to have lasted at least ∼1600 years from ∼3.5 to ∼1.9 kyr BP.
Do House Wrens (Troglodytes aedon) add spider egg cases to their nests for heterospecific cleaning?
Authors: Gable C.L. , Underwood T.J. , Setliff G.P.
Published: September 2018

House Wrens (Troglodytes aedon Vieillot, 1809) regularly add spider egg cases (Arachnida: Araneae) to their nests, which may be an example of heterospecific cleaning. This behavior involves one animal employing another to remove parasites from their nests. In House Wren nests, juvenile spiders hatching from egg cases may facilitate the reduction of mites that feed on nestlings. We tested this ectoparasite reduction hypothesis by monitoring House Wren nests for spider egg cases and by collecting completed nests to compare the number of spider egg cases and Dermanyssus hirundinis (Hermann, 1804) mites. No significant relationship was found between the number of spider egg cases and number of D. hirundinis mites in nests. We also found no significant relationship between the number of D. hirundinis mites in nests and the body condition of nestlings. Finally, no significant difference was found between the number of D. hirundinis mites in early versus late season nests, but significantly more spider egg cases were added to late season nests. Of a subsample of spider egg cases dissected, we found that 28% contained spider eggs or embryos. We also identified three species of juvenile spiders from House Wren nests using DNA barcoding. Overall, we found no evidence that spider egg cases reduce the number of D. hirundinis mites or engender better quality offspring in House Wren nests.
Load-carrying capacity of filament-wound E glass/epoxy composite rings
Authors: Beylergil Bertan
Published: September 2018

In this study, three different types of E glass/epoxy composite rings were produced by the filament-winding technique: (i) O ring (Type A), (ii) ring with a radial notch (Type B), and (iii) C-shaped ring (Type C). To evaluate the effect of winding angle on the load-carrying capacity of composite rings, five different winding angles were considered: ±45°, ±55°, ±65°, ±75°, and ±88°. The load capacity of the manufactured composite rings in the tensile hoop direction were determined experimentally using a special test fixture. The experimental results showed that the optimum winding angle was ±88° in terms of load-carrying capacity. The rings wound at 55° had the lowest load-carrying capacity. Type A rings had the highest capacity while Type C rings had the lowest.
On a Toda lattice hierarchy: Lax pair, integrable symplectic map and algebraic–geometric solution
Authors: Yang Xiao , Du Dianlou
Published: September 2018

A Toda lattice hierarchy is studied by introducing a new spectral problem which is a discrete counterpart of the generalized Kaup–Newell spectral problem. Based on the Lenard recursion equation, Lax pair of the hierarchy is given. Further, the discrete spectral problem is nonlinearized into an integrable symplectic map. As a result, an algebraic–geometric solution in Riemann theta function of the hierarchy is obtained. Besides, two equations, the Volterra lattice and a (2[Formula: see text]+[Formula: see text]1)-dimensional Burgers equation with a discrete variable, yielded from the hierarchy are also solved.
Evaluation of Software Reusability Based on Coupling and Cohesion
Authors: Priyalakshmi G. , Latha R.
Published: September 2018

Code reuse has become very popular among software developers in recent times since it saves time and resources. One of the significant difficulties to software reuse is the time pertaining to assess the fitness of the reusable code components. Over the recent years, code search engines have made momentous advancement in establishing the semantic suitability of software components for new usage scenarios. But the issue of evaluating software components based on their nonfunctional suitability has been overlooked to a large extent. The maintenance and reusability of software systems are highly influenced by the structural properties of system classes like complexity, size, coupling, cohesion, etc. The quality of object-oriented code or design artifacts is commonly measured by analyzing the structure of these artifacts in terms of the interdependencies of classes and components as well as their internal elements. In this paper, we perform an empirical analysis on Python packages for the two measures namely coupling and cohesion. The coupling score of a module is computed as module imports and the cohesion score of a module is evaluated as call dependency between classes and global functions of the module. Finally, the proposed work evaluates a package in terms of reusability score which is a cumulative score of the coupling scores and cohesion scores of all the modules within the package. The study has evaluated 15 different packages and five different releases of one single package for reusability. We have empirically tested that the Halstead’s effort metric is inversely proportional to the reusability score. The reusability score was validated using four code detuners. The proposed work was compared with the existing metrics namely cyclomatic complexity and maintainability Index showing satisfactory results.
On Darboux Theorem for symplectic forms on direct limits of symplectic Banach manifolds
Authors: Pelletier Fernand
Published: September 2018

Given an ascending sequence of weak symplectic Banach manifolds on which the Darboux Theorem is true, we can ask about conditions under which the Darboux Theorem is also true on the direct limit. We will show that, in general, without very strong conditions, the answer is negative. In particular, we give an example of an ascending symplectic Banach manifolds on which the Darboux Theorem is true but not on the direct limit. In the second part, we illustrate this discussion in the context of an ascending sequence of Sobolev manifolds of loops in symplectic finite-dimensional manifolds. This context gives rise to an example of direct limit of weak symplectic Banach manifolds on which the Darboux Theorem is true around any point.
Analytic solutions of fractional ODEs and PDEs
Authors: Aghili A.
Published: September 2018

In this work, it is shown that the combined use of exponential operators and integral transforms provides a powerful tool to solve space fractional partial differential equation with non-constant coefficients in three dimensions. Also, a variety of Lamb–Bateman singular integral equation and a non-homogeneous time fractional Kd.V of order [Formula: see text] are solved. Constructive examples are also provided.
Covariant functor of soft Γ-hyperrings
Authors: Ostadhadi-Dehkordi S. , Shum K. P.
Published: September 2018

It is known that a soft [Formula: see text]-hyperring is a generalization of soft ring. The concept of soft [Formula: see text]-hyperring was first introduced by Zhan et al. In fact, Zhan et al. also established three isomorphism theorems of soft rings in 2012. Science then, the study of soft [Formula: see text]-hyperrings has been rapidly grown. The aim of this paper is to consider the equivalence relation on a [Formula: see text]-hyperring previously defined by Zhan et al. It is proved that the above relation is strongly regular and hyperaddition on all quotient soft [Formula: see text]-hyperrings. Also, by using the fundamental relations on [Formula: see text]-hyperrings and hypergroups, we define covariant functor between the category soft [Formula: see text]-hyperrings and soft rings.
A polynomial-time weighted path-following interior-point algorithm for linear optimization
Authors: Achache Mohamed
Published: September 2018

In this paper, a weighted short-step primal-dual path-following interior-point algorithm for solving linear optimization (LO) is presented. The algorithm uses at each interior-point iteration a full-Newton step, thus no need to use line search, and the strategy of the central-path to obtain an [Formula: see text]-approximated solution of LO. We show that the algorithm yields the iteration bound, namely, [Formula: see text]. This bound is currently the best iteration bound for LO. Finally, some numerical results are reported in order to analyze the efficiency of the proposed algorithm.
Applications of natural language processing (NLP) for improving classroom learning experiences using student surveys
Authors: Kuiper Patrick , Hood Karoline
Published: September 2018

Academic institutions often assess the efficacy of courses by surveying students. These surveys are critical in structuring course content and evaluating instruction. Given the critical function of surveys for academic institutions, it is essential that surveys obtain data which is precise and accurate. Currently most institutions construct surveys employing the Likert scale: questions that require students to map their opinion on precise topics to a discrete, quantitative domain. These surveys uniformly weight response data, irrespective of student interest. We argue greater accuracy may be obtained by building Student-Directed Discussion Surveys (SDDSs) — surveys with several open-ended, student-directed questions, requiring free text responses. SDDSs retain precision by employing several Natural Language Processing (NLP) techniques including word frequency and sentiment analysis. We use SDDSs to improve course content and evaluate survey accuracy by comparing the results of an SDDS to a Likert-scaled survey administered to an overlapping population. We find that the results of these two survey techniques diverge when topics become increasingly significant to respondents. These results, in addition to the documented issues with Likert-scaled surveys, lead to the conclusion that SDDSs may provide more informative and insightful results.
Symposium report on “Examining the Changing Landscape of Course Delivery and Student Learning”: Experimental Biology 2017
Authors: Halpin Patricia A. , Golden Lynelle , Hagins Karah Zane , Waller Steve , Gopalan Chaya
Published: September 2018

An APS Teaching Section symposium entitled “Examining the Changing Landscape of Course Delivery and Student Learning” was offered at the Experimental Biology conference on April 24th, 2017, in Chicago, IL. The symposium focused on alternative delivery modes of physiology education, from undergraduate to professional programs. Lecture used to be the gold standard and proven method by which students learned, but the course delivery method is rapidly changing. While there is still significant skepticism about the quality and level of student engagement in online learning, it is being offered widely due to increased demand and due to other benefits, such as the flexibility and convenience. Universities with several campuses may now synchronize lectures between campuses, utilizing video conference technology, thus bypassing the need for instructors on each campus. Other modes of delivery include online lectures with laboratories scheduled on campus. Offering biology laboratories online is on the rise but to counter skepticism, more studies are needed to demonstrate that online laboratories effectively meet laboratory objectives. The Massive Open Online Course (MOOC) offers many courses for free and challenges the role of universities. Assessment of the effectiveness of MOOCs and online courses is critical, as some of the concerns raised about them include level of student engagement in learning and the social aspect of interaction with peers and faculty.
Collaborative active learning: bioimpedance and anthropometry in higher education
Authors: Bravo Rafael , Ugartemendia Lierni , Cubero Javier , Uguz Cihangir , Rodríguez Ana B.
Published: September 2018

Research in the health sciences devotes much attention to overweight and obesity and, consequently, to body composition. In recent years, traditional body measures have been questioned as efficient variables in health sciences due to the fact that they cannot give information about body fat mass. Our aim is to teach how to analyze body composition through anthropometry and bioelectrical impedance analysis to our “Physiology of Vegetative and Reproductive Functions” students, who are studying for their degree in Biology. We proposed project-oriented-learning to promote collaborative interactions among students. Fifty-two students voluntarily formed five groups; they worked with the concepts of basal metabolic rate and body composition from a theoretical point of view and later transformed these concepts into a practical perspective by preparing a manuscript in groups with objectives proposed by our teaching team. In this research, we show a collaborative educational scenario for university students in which students are tutored from a constructivist perspective to promote social interactions, resulting in new knowledge acquisition.
Disruption of brain-derived neurotrophic factor production from individual promoters generates distinct body composition phenotypes in mice
Authors: McAllan Liam , Maynard Kristen R. , Kardian Alisha S. , Stayton Amanda S. , Fox Shelby L. , Stephenson Erin J. , Kinney Clint E. , Alshibli Noor K. , Gomes Charles K. , Pierre Joseph F. , Puchowicz Michelle A. , Bridges Dave , Martinowich Keri , Han Joan C.
Published: September 2018

Brain-derived neurotrophic factor (BDNF) is a key neuropeptide in the central regulation of energy balance. The Bdnf gene contains nine promoters, each producing specific mRNA transcripts that encode a common protein. We sought to assess the phenotypic outcomes of disrupting BDNF production from individual Bdnf promoters. Mice with an intact coding region but selective disruption of BDNF production from Bdnf promoters I, II, IV, or VI (Bdnf-e1−/−, -e2−/−, -e4−/−, and -e6−/−) were created by inserting an enhanced green fluorescent protein-STOP cassette upstream of the targeted promoter splice donor site. Body composition was measured by MRI weekly from age 4 to 22 wk. Energy expenditure was measured by indirect calorimetry at 18 wk. Food intake was measured in Bdnf-e1−/−and Bdnf-e2−/−mice, and pair feeding was conducted. Weight gain, lean mass, fat mass, and percent fat of Bdnf-e1−/−and Bdnf-e2−/−mice (both sexes) were significantly increased compared with wild-type littermates. For Bdnf-e4−/−and Bdnf-e6−/−mice, obesity was not observed with either chow or high-fat diet. Food intake was increased in Bdnf-e1−/−and Bdnf-e2−/−mice, and pair feeding prevented obesity. Mutant and wild-type littermates for each strain (both sexes) had similar total energy expenditure after adjustment for body composition. These findings suggest that the obesity phenotype observed in Bdnf-e1−/−and Bdnf-e2−/−mice is attributable to hyperphagia and not altered energy expenditure. Our findings show that disruption of BDNF from specific promoters leads to distinct body composition effects, with disruption from promoters I or II, but not IV or VI, inducing obesity.
Experimental Investigation and Analysis of Triggering Mechanism for Fault‐Slip Bursts of the Tunnel Surrounding Rock with External Disturbance
Authors: Jiang Hai-ming , Li Jie , Deng Shu-xin , Wang De-rong , Zhao Xiao
Published: September 2018

Shear‐slip type rockburst is one of the most common geohazards confronted in deep underground excavations, which can easily occur after external disturbances. Owing to the sudden occurrence and significant damage caused, investigating the mechanism of these shear‐slip type disasters is of tremendous significance in ensuring the safety of underground construction projects. In this paper, our attentions are mainly paid to investigate the necessary conditions and critical energy conditions of fault‐slip bursts of the tunnel surrounding rock triggered by external disturbances. First, a simplified model for simulating the sliding instability phenomenon occurring in a blocky rock system under external disturbance is established. Next, using a newly developed testing system for the dynamic behaviour of blocky rock masses, a series of experiments to reproduce the sliding instability phenomenon are conducted; the purple sandstone block system is subjected to the combined effect of a vertical impact load and horizontal constant force. The influence of vertical impact energy on the sliding instability is analysed. The experimental results show that the critical energy of the impact load triggering the blocky rock mass slip instability depends on the shear force, and the higher the shear force, the lower is the external disturbance required. Furthermore, a one‐dimensional dynamic calculation model is established to develop a better insight regarding the mechanism of the slip instability induced by external disturbances. A dimensionless energy parameter was introduced to quantifiably characterize the critical conditions of different types of fault‐slip events. Theoretical analysis and calculations are presented, and the results agree with experimental observations.
Impact of Intra-Abdominal Adhesion on Dialysis Outcome in Peritoneal Dialysis Patients
Authors: Cheng Ben-Chung , Tsai Nai-Wen , Lai Yun-Ru , Huang Chin-Cheng , Lu Cheng-Hsien
Published: September 2018

Background.Peritoneal dialysis (PD) is an increasingly popular therapeutic option for patients with advanced renal failure. However, intra-abdominal adhesions (IAA) represent a major unsolved problem in adequate PD performance. In this study, we investigated the role of previous abdominal surgery on the presence of subsequent IAA as well as outcomes in those patients with PD who had subsequent IAA.Methods.Two hundred and two patients who received continuous ambulatory peritoneal dialysis were prospectively enrolled in this study. We compared the PD adequacy indices and outcomes for technical failure in patients with and without subsequent IAA at presentation and a minimum of 2 years of follow-up.Results.Subsequent IAA accounted for 19% (38/202) of patients. Patients who had previous abdominal surgery had higher risks of subsequent IAA especially those patients who had higher mean ages (P=0.023). PD adequacy indices including both 24-hour dialysate volume and peritoneal WCcr L/week/1.73 m2were significantly lower in patients who had, as compared to those who did not have subsequent IAA (P=0.003 and 0.018, respectively). Although patients who had subsequent IAA had decreased PD adequacy, the development of technical failures during PD maintenance did not show significant differences at the 2-year minimum follow-up study.Conclusions.Subsequent IAA is not rare, especially in high-risk patients including those with previous abdominal surgery and higher mean ages. Although decreased PD adequacy after IAA was found, the development of technical failures was not significantly different at the 2-year minimum follow-up study.
A Multiperiodic Optimization Formulation for the Operation Planning of Free-Floating Shared Bike in China
Authors: Li Meiyu , Wang Xifu , Zhang Xi , Yun Lifen , Yuan Yuan
Published: September 2018

Internet shared bike has trigged a revolution on the public bicycle utilization in China for various characteristics such as free-floating, intelligent unlocking, mobile payment, intelligent integration, and optional serving. It attracts many users and meanwhile accumulates the development of short-distance alternative trip. This paper has designed an optimization model for the deployment and travel of free-floating bike sharing (FFBS) among small regions. For a given demand under the constraint of overload of flexile stations, the model makes a decision on the minimum number of bike deployments in the system and the planning of bike movement between stations at different time periods. It maximizes the profit of operators during the whole planning horizon and meanwhile satisfices the demand and minimizes the overload situation of stations. The proposed approach is verified with numerical example, aiming to help operators to program and manage systems in a more efficient way.
Optimal Multirobot Coverage Path Planning: Ideal-Shaped Spanning Tree
Authors: Gao Chunqing , Kou Yingxin , Li Zhanwu , Xu An , Li You , Chang Yizhe
Published: September 2018

The present paper attempts to find the optimal coverage path for multiple robots in a given area including obstacles. For single robot coverage path planning (CPP) problem, an improved ant colony optimization (ACO) algorithm is proposed to construct the best spanning tree and then obtain the optimal path, which contributes to minimizing the energy/time consumption. For the multirobot case, first the DARP (Divide Areas based on Robots Initial Positions) algorithm is utilized to divide the area into separate equal subareas, so much so that it transforms the mCPP problem into several CPP problems, degrading the computation complexity. During the second phase, spanning tree in each subarea is constructed by the aforementioned algorithm. In the last phase, the specific end nodes are exchanged among subareas to achieve ideal-shaped spanning trees, which can also decrease the number of turns in coverage path. And the complete algorithms are proven to be approximately polynomial algorithms. Finally, the simulation confirms the complete algorithms’ advantages: complete coverage, nonbacktracks, minimum length, zero preparation time, and the least number of turns.