bluuebunny/crossref_metadata_2025 huggingface dataset:
Métodos semiempíricos para la evaluación rápida de orbitales frontera en la clasificación de agonistas y antagonistas de la subunidad NR1 de los receptores iGluR-NMDA
Authors: Yosa-Reyes Juvenal , Clavijo-Buriticá Diana Carolina , Estévez-Bretón Riveros Carlos Manuel , Acevedo Orlando Emilio
Published: November 2015

The ionotropic glutamate receptors activated by N-Methyl-D-Aspartate (iGluR-NMDA) are of great importance in pharmacology since they are involved in neurodegenerative and neuropsychiatric disorders; they even participate in processes such as synaptic plasticity that are essential for memory formation.  Subunit NR1 iGluRs-NMDA is of paramount importance for the appropriate activation of this type of receptors; in fact,  many of the pharmaceutical products studied for the abovementioned disorders are targeted specifically to the NR1 subunit. Previous studies have shown that the lowest energy unoccupied molecular orbital (LUMO) can be used as a parameter to estimate the agonist and antagonist activity of the NR1subunit. Objective. Evaluate the semiemprical method CNDO for the rapid calculation of the LUMO energy with the aim of preparing a simple model for the in silico design of new pharmacological substances. Materials and methods. 168 molecules with agonist and antagonist activity in the NR1 subunit were selected. Energy of each structure was optimized and then we calculated the energy of the frontier orbital, the LogP, total energy, capacity of forming hydrogen bonds, binding energy, and dipolar moment. Results. We demonstrate that LUMO energy is enough for discriminating agonist and antagonist molecules of the NR1 subunit and that the CNDO method evaluates these properties in a rapid and efficient way. Conclusions.  The CNDO method facilitates a rapid calculation, enabling a future development of effective procedures for the characterization of potential pharmacological substances acting on this particular site.

Key words: iGluR-NMDA, LUMO, agonist, antagonist, CNDO
Relación entre comunidad íctica y cobertura vegetal riparia en períodos hidrológicos (Eje Cafetero, Colombia)
Authors: Pérez-Mayorga María Angélica , Prada-Pedreros Saúl
Published: November 2015

Objective. To assess the relationship between structure and diet of the fish community and the riparian vegetation cover (RVC), in two hydrological periods (HYPE) in streams of the La Vieja river basin. Materials and methods. Collections were done with electrofishing and rapiché in March and May 2010. Efficiency of sampling effort was assessed with the estimator Chao2. Structure was analyzed using the indices of richness, dominance, diversity and evenness which were compared with an ANOVA. Gastrointestinal contents were analysed with the indices of vacuity coefficient, frequency, volume and food importance. We examined the relationship among diet, HYPE and RVC using the multiple correlation coefficient (r), the coefficient of determination (r2) and a Canonical Correspondence Analysis (CCA). Results. According to the Chao2 estimator, in most streams the fish species richness values are representative. There were no significant differences (P>0.05) among the structural variables, the HYPE and the RVC. According to r and r2 the diet of most fish species did not vary as a function of RVC and HYPE; however, according to the CCA diet varies as a function of HYPE but not of RVC. Conclusions. The fish community structure did not show changes according to RVC and HYPE. Although most species showed no changes in their diet, the community did show changes in diet according to HYPE, due to a change in composition; however diet changes were not detected by RVC.

Key words: coffee-growing region, diet, fish community, hydrological period, riparian vegetation cover, structure.
Diseño de un medio para la producción de un co-cultivo de bacterias fosfato solubilizadoras con actividad fosfatasa
Authors: Angulo-Cortés Jimena Paola , García-Díaz Anamaría , Pedroza Aura Marina , Martínez-Salgado María Mercedes , Gutiérrez-Romero Viviana
Published: November 2015

Objective. To design a complex culture media for the production of biomass and acid phosphatases from phosphate-solubilizing bacteria isolated from soil. Materials and methods. Phosphate-solubilizing bacteria were isolated from oil palm crop soil samples and selected on SMRS1 agar, which were then assessed with antagonism tests to verify their aptitude to form a co-culture. A Box-Behnken experimental design was applied to
evaluate the effect of each one of the culture media components on the production of biomass and phosphatase enzymes at a laboratory scale. Finally, microbial growth and enzyme production curves were carried out in order to determine their production times. Results. Five phosphate-solubilizing bacterial strains were isolated and three of them were selected based on their solubilization indices.These Gram negative strains with bacillus morphology were identified as A, B and C; their solubilization indices were 2.03, 2.12, and 2.83, respectively. According to the ANOVA analyses for the Box-Behnken design, the only factor which had a significant effect on the phosphatase activity (p<0.01) was hydrolyzed yeast, and the formulation that generated the highest biomass concentration and phosphatase activity (p<0.01) contained 10, 15 and 2.5 gL-1 of phosphoric rock, sucrose and hydrolyzed yeast, respectively. After 24 hours of incubation at 100 rpm, the highest values of biomass and phosphatase activity were obtained: 11.8 logarithmic units of CFU and 12.9 phosphatase units. Conclusion. We determined that the culture media based on phosphoric rock 10 gL-1, hydrolyzed yeast 2.5 gL-1 and commercial sucrose 15 gL-1 was ideal for the production of biomass and phosphatases by the strains evaluated; likewise, we proved that the hydrolyzed yeast was the only factor significantly influential for the production of phosphatases.

Key words: bio-inoculants, phosphate solubilizing microorganisms, phosphatase activity, Box Behnken design.
Expression of inhibitory receptors on CD4+ and CD8+ T cells from healthy Colombian donors
Authors: Rico- Lombana Alejandra Rico- Lombana , Mateus Jose , Lasso Paola , González John Mario , Puerta Concepción Judith , Cuéllar Adriana
Published: November 2015

T cell activation involves positive cellular signals that promote effector functions and negative signals that contribute to the regulation of these responses. These regulatory signals are generated upon activation of receptors on T cells that include CD160, 2B4, Programmed Death-1 and CTLA-4. Objective. To evaluate the expression of inhibitory receptors like CD160, 2B4, Programmed Death-1 and CTLA-4 on CD4+ and CD8+ T cells from healthy Colombian donors. Materials and methods. Peripheral blood mononuclear cells from 30 healthy donors from Bogotá (Colombia) were obtained via Ficoll-Hypaque density gradient and cells were stained with specific conjugated antibodies previously titrated. Results. The CD160, 2B4, and Programmed Death-1 inhibitory markers were detected on CD4+ T cells
with expression levels of 0.35%, 1.04%, and 1.35%, respectively. On CD8+ T cells, these markers were expressed at higher levels: 16%, 8.97%, and 4.3%, respectively. In contrast to the other receptors, CTLA-4 frequency of expression showed no significant difference between CD4+ (1.56%) and CD8+ (1.53%) T cells. Frequency of CD160/2B4 and CTLA-4/ Programmed Death-1 coexpression was 0.18% and 0.09% on CD4+ cells, and 4.02% and 0.2% on CD8+ T cells. Conclusions. This is the first report showing the frequency of inhibitory receptors such as CD160, 2B4, Programmed Death-1, and CTLA-4 on CD4+ and CD8+ T cells from healthy Colombian donors. Our findings serve as a baseline for the analysis and comparison of these receptors in Colombian populations with different disease conditions.

Key words: inhibitory receptors, T cells
Multiple regression as a preventive tool for determining the risk of Legionella spp.
Authors: Gea-Izquierdo Enrique
Published: November 2015

Objective. To determine the interrelationship between health & hygiene conditions for prevention of legionellosis, the composition of materials used in water distribution systems, the water origin and Legionella pneumophila risk. Material and methods. Include a descriptive study and multiple regression analysis on a sample of golf course sprinkler irrigation systems (n=31) pertaining to hotels located on the Costa del Sol (Malaga, Spain). The study was carried out in 2009. Results. Presented a significant lineal relation, with all the independent variables contributing significantly (p<0.05) to the model’s fit. The relationship between water type and the risk of Legionella, as well as the material composition and the latter, is lineal and positive. In contrast, the relationship between health-hygiene conditions and Legionella risk is lineal and negative. Conclusion. The characterization of Legionella pneumophila concentration, as defined by the risk in water and through use of the predictive method, can contribute to the consideration of new influence variables in the development of the agent, resulting in improved control and prevention of the disease.

Key words: Legionella pneumophila, legionnaires’ disease, multiple regression, hotel golf courses, sprinklers.
Rickettsiosis, una enfermedad letal emergente y re-emergente en Colombia
Authors: Quintero Vélez Juan Carlos , Hidalgo Marylin , Rodas González Juan David
Published: November 2015

Rickettsiosis was first described in Colombia in 1937 by Dr Luis Patiño during an outbreak of a disease with unspecific signs. Rickettsia is a genus of Gram-negative intracellular obligatory bacteria having caused several epidemics around the world, and are transmitted mainly by ticks, fleas, lice and mites. The most fatal within this group of diseases is known as Rocky Mountain Spotted Fever (RMSF), which is caused by Rickettsia rickettsia. There is also the endemic typhus caused by Rickettsia typhi and epidemic typhus caused by Rickettsia prowazekii. In Colombia, several outbreaks of RMSF have occurred during the last decade. The best known among those have hit the municipalities of Necoclí and Turbo, in Antioquia in 2006 and 2008 respectively, and Los Cordobas in the department of Cordoba in 2007. The goal of this review is to describe the state of the art of rickettsiosis, a forgotten lethal disease that has re-emerged in our country, and leave some questions as an inspiration for future research that will hopefully lead scientists to a better understanding of this entity potentially endemic in some areas of Colombia.

Key words: outbreak, emerging, reservoir, rickettsiosis, vector, typhus, zoonoses.
Simultaneous decolorization and detoxification of black reactive 5 using TiO2 deposited over borosilicate glass
Authors: Puentes-Cárdenas Johana , Florido-Cuellar Alex , Cardona-Bedoya Jairo , Bohorquez-Echeverry Paola , Campos-Pinilla Claudia , Gutiérrez-Romero Viviana , Pedroza-Rodríguez Aura
Published: November 2015

Objective. Removal and detoxification of azo dye by photocatalysis with TiO2. Materials and methods. TiO2 films were prepared by sedimentation at pH 1.3, using as support a borosilicate glass, annealed for 1 hour at 450 °C. Physical characterization was performed by Scanning Electron Microscopy, X-ray diffraction and UV/VIS spectrometry. Dye Black Reactive 5 removal was carried-out in a quartz photo-reactor. Results. Optical characterization revealed the films displayed evident TiO2 spherical particles of various irregular sizes, porous, and without fractures. The average crystal size was 77.5 nm and 77.7 nm for 50 °C (dried temperature) and 450 ºC (annealed temperature) respectively. The energy of the band gap (GAP) was 3.02 and 2.68 eV respectively. Maximum concentration of dye that negatively affected color removal was 80 mg/L (17%). At lower dye’s concentrations (10, 50 and 70mg/L) decolorization was greater than 80%. TiO2 films were reused for five consecutive cycles of 6 hours at 10 mg/L (>80%), and three cycles of 10 hours at 70 mg/L (> 80%). Toxicity results demonstrate that Daphnia magna was more sensitive than Lactuca sativa. Conclusions. TiO2 films obtained by sedimentation demonstrated a high reactive black 5 decolorization and COD removal (86% and 100%), as well as toxicity reduction.

Key words: photocatalysis with TiO2, sedimentation techniques, reactive black 5, Lactuca sativa and Daphnia magna.
Biosíntesis de alcaloides bencilisoquinolínicos
Authors: De-La-Cruz Chacón Iván , González-Esquinca Alma Rosa , Riley-Saldaña Christian Anabí
Published: November 2015

The benzylisoquinoline alkaloids (BIA) are specialized metabolites with an ancient phylogenetic distribution, but still preserved in modern clades. Some of them, such as morphine, sanguinerine or berberine, are important for modern medicine. This review discusses the highlights of the current state of the biosynthesis of BIA. There have been studies that show the biosynthesis of 22 of these nitrogenous metabolites. In their formation there are 43 enzymes grouped into oxidoreductases, transferases and lyases, which in some cases represent atypical examples of the manner in which the secondary metabolism diversification was
originated. Two of these examples are the cytochrome proteins P450 (P450), with catalytic activities for ABI route, or the norcoclaurine synthase enzyme (NCS), which share substantial identity with defense allergenic proteins. Likewise, there are genetic advances that have produced the characterization of 30 enzymes, allowing knowledge of regulatory processes. Another interesting aspect is the compartmentation of the biosynthesis sites and accumulation of BIA, since in several cases they are spatially separated and in different species, or in the same species several types of cells may be involved. This has suggested intra and intercellular transport of alkaloids, precursors and enzymes, and it has been documented berberine transport between the cytoplasm and the vacuoles of storage. The picture for the biosynthesis of BIA has been constructed with exemplary studies of alkaloids with pharmacological importance.
Key words: specialized metabolism, secondary metabolism, cellular transport, cell compartment, tissue-specific regulation
Evaluación de un sistema para la micorrización in vitro en plantas de mora de castilla (Rubus glaucus, Benth)
Authors: Pérez-Moncada Urley Adrian , Ramírez-Gómez María Margarita , Núñez-Zarante Víctor Manuel , Franco-Correa Marcela , Roveda-Hoyos Gabriel
Published: November 2015

Objective. Obtain an in vitro mycorrhization system in autotrophic culture systems of blackberry plants (Rubus glaucus, Benth). Materials and methods. We used spores and root fragments with vesicles of Arbuscular Mycorrhizal Fungus (AMF) Glomus sp (GEV02). We established an autotrophic culture system of blackberry plantlets comparing two methods of direct inoculation of the AMF. We measured the number of spores produced, the length of the extraradical mycelium as well as the percentage of colonization of the AMF. Additionally, we measured the shoot and root length, and the fresh and dry weight of the leaf and root parts to determine the plant development. Results. The autotrophic culture system was successful for blackberry plants (Rubus glaucus, Benth; an optimal shoot and root growth was observed. Additionally, we obtained a system that allowed the development of Glomus sp. in in vitro conditions, with the formation of structures typical of the symbiosis as well as a good intraradical colonization, with the production of arbuscules and vesicles, development of extraradical mycelium with branched hyphae, and formation of new spores. Conclusion. For the first time, micropropagated blackberry plants associated successfully with an AMF under in vitro conditions, enabling the development of the symbiotic system AMF Glomus sp. associated to roots of micropropagated blackberry plantlets.
Key words: arbuscular mycorrhizal fungi (AMF), autotrophic culture, Rubus glaucus Benth, Glomus sp. (GEV02), in vitro mycorrhization.
Authorship of scientific articles within an ethical-legal framework: quantitative model
Authors: Vallejo Martha , Acosta Alberto , Palacio Correa Gustavo
Published: November 2015

Determining authorship and the order of authorship in scientific papers, in modern interdisciplinary and interinstitutional science, has become complex at a legal and ethical level. Failure to define authorship before or during the research, creates subsequent problems for those considered authors of a publication or lead authors of a work, particularly so, once the project or manuscript is completed. This article proposes a quantitative and qualitative model to determine authorship within a scientific, ethical and legal frame. The principles used for the construction of this design are based on 2 criteria: a) stages of research and scientific method involving: 1. Planning and development of the research project, 2. Design and data collection, 3. Presentation of results, 4. Interpretation of results, 5. Manuscript preparation to disseminate new knowledge to the scientific community, 6. Administration and management, and b) weighting coefficients in each phase, to decide on authorship and ownership of the work. The model also considers and distinguishes whether the level and activity performed during the creation of the work and the diffusion of knowledge is an intellectual or practical contribution; this distinction both contrasts and complements the elements protected by copyright laws. The format can be applied a priori and a posteriori to the completion of a project or manuscript and can conform to any research and publication. The use of this format will quantitatively resolve: 1. The order of authorship (first author and co-author order), 2. Determine the inclusion and exclusion of contributors, taking into account ethical and legal principles, and 3. Percentages of economic rights for each authors.

 

Descarga de material suplementario / Supplement material download

(A, B, C, D)

 

 
Dynamic Behavior of Elastic Bars and Beams Impinging on Ideal Springs
Authors: Wang Song , Wang Yong , Huang Zhilong , Yu T. X.
Published: November 2015

The impacting and rebounding behaviors of straight elastic components are investigated and a unified approach is proposed to analytically predict the whole process of the collision and rebounding of straight elastic bars and beams after each of them impinges on ideal (massless) elastic spring(s). The mathematical problems with definitive solution are formulated, respectively, for both the constrained-motion and free-motion stages, and the method of mode superposition, which is concise and straightforward especially for long-time interaction and multiple collision cases, is successfully utilized by repeatedly altering boundary and initial conditions for these successive stages. These two stages happen alternatively and the collision process terminates when the constrained motion no longer occurs. In particular, three examples are investigated in detail; they are: a straight bar impinges on an ideal elastic spring along its axis, a straight beam vertically impinges on an ideal elastic spring at the beam's midpoint, and a straight beam vertically impinges on two ideal springs with the same stiffness at the beam's two ends. Numerical results show that the coefficient of restitution (COR) and the nondimensional rebounding time (NRT) only depend on the stiffness ratio between the ideal spring(s) and the elastic bar/beam. Collision happens only once for the straight bar impinging on spring, while multiple collisions occur for the straight beam impinging on springs in the cases with large stiffness ratio. Once multiple collisions occur, COR undergoes complicated fluctuation with the increase of stiffness ratio. Approximate analytical solutions (AASs) for COR and NRT under the cases of small stiffness ratio are all derived. Finally, to validate the proposed approach in practical collision problems, the influence of the springs' mass on the collision behavior is demonstrated through numerical simulation.
Evaluation of Anatomical and Functional Hip Joint Center Methods: The Effects of Activity Type, Gender, and Proximal Reference Segment
Authors: McGibbon C. A. , Fowler J. , Chase S. , Steeves K. , Landry J. , Mohamed A.
Published: November 2015

Accurate hip joint center (HJC) location is critical when studying hip joint biomechanics. The HJC is often determined from anatomical methods, but functional methods are becoming increasingly popular. Several studies have examined these methods using simulations and in vivo gait data, but none has studied high-range of motion activities, such a chair rise, nor has HJC prediction been compared between males and females. Furthermore, anterior superior iliac spine (ASIS) marker visibility during chair rise can be problematic, requiring a sacral cluster as an alternative proximal segment; but functional HJC has not been explored using this approach. For this study, the quality of HJC measurement was based on the joint gap error (JGE), which is the difference in global HJC between proximal and distal reference segments. The aims of the present study were to: (1) determine if JGE varies between pelvic and sacral referenced HJC for functional and anatomical methods, (2) investigate which functional calibration motion results in the lowest JGE and if the JGE varies depending on movement type (gait versus chair rise) and gender, and (3) assess whether the functional HJC calibration results in lower JGE than commonly used anatomical approaches and if it varies with movement type and gender. Data were collected on 39 healthy adults (19 males and 20 females) aged 14–50 yr old. Participants performed four hip “calibration” tests (arc, cross, star, and star-arc), as well as gait and chair rise (activities of daily living (ADL)). Two common anatomical methods were used to estimate HJC and were compared to HJC computed using a published functional method with the calibration motions above, when using pelvis or sacral cluster as the proximal reference. For ADL trials, functional methods resulted in lower JGE (12–19 mm) compared to anatomical methods (13–34 mm). It was also found that women had significantly higher JGE compared to men and JGE was significantly higher for chair rise compared to gait, across all methods. JGE for sacrum referenced HJC was consistently higher than for the pelvis, but only by 2.5 mm. The results indicate that dynamic hip range of movement and gender are significant factors in HJC quality. The findings also suggest that a rigid sacral cluster for HJC estimation is an acceptable alternative for relying solely on traditional pelvis markers.
Computationally Optimizing the Compliance of a Biopolymer Based Tissue Engineered Vascular Graft
Authors: Harrison Scott , Tamimi Ehab , Uhlorn Josh , Leach Tim , Vande Geest Jonathan P.
Published: November 2015

Coronary heart disease is a leading cause of death among Americans for which coronary artery bypass graft (CABG) surgery is a standard surgical treatment. The success of CABG surgery is impaired by a compliance mismatch between vascular grafts and native vessels. Tissue engineered vascular grafts (TEVGs) have the potential to be compliance matched and thereby reduce the risk of graft failure. Glutaraldehyde (GLUT) vapor-crosslinked gelatin/fibrinogen constructs were fabricated and mechanically tested in a previous study by our research group at 2, 8, and 24 hrs of GLUT vapor exposure. The current study details a computational method that was developed to predict the material properties of our constructs for crosslinking times between 2 and 24 hrs by interpolating the 2, 8, and 24 hrs crosslinking time data. matlab and abaqus were used to determine the optimal combination of fabrication parameters to produce a compliance matched construct. The validity of the method was tested by creating a 16-hr crosslinked construct of 130 μm thickness and comparing its compliance to that predicted by the optimization algorithm. The predicted compliance of the 16-hr construct was 0.00059 mm Hg−1 while the experimentally determined compliance was 0.00065 mm Hg−1, a relative difference of 9.2%. Prior data in our laboratory has shown the compliance of the left anterior descending porcine coronary (LADC) artery to be 0.00071 ± 0.0003 mm Hg−1. Our optimization algorithm predicts that a 258-μm-thick construct that is GLUT vapor crosslinked for 8.1 hrs would match LADC compliance. This result is consistent with our previous work demonstrating that an 8-hr GLUT vapor crosslinked construct produces a compliance that is not significantly different from a porcine coronary LADC.
Viral Determinants of miR-122-Independent Hepatitis C Virus Replication
Authors: Hopcraft Sharon E. , Azarm Kristopher D. , Israelow Benjamin , Lévêque Nicolas , Schwarz Megan C. , Hsu Tien-Huei , Chambers Matthew T. , Sourisseau Marion , Semler Bert L. , Evans Matthew J.
Published: November 2015

Hepatitis C virus (HCV) is the leading cause of liver cancer in the Western Hemisphere. HCV infection requires miR-122, which is expressed only in liver cells, and thus is one reason that replication of this virus occurs efficiently only in cells of hepatic origin. To understand how HCV genetics impact miR-122 usage, we knocked out miR-122 using clustered regularly interspaced short palindromic repeat (CRISPR) technology and adapted virus to replicate in the presence of noncognate miR-122 RNAs. In doing so, we identified viral mutations that allow replication in the complete absence of miR-122. This work provides new insights into how HCV genetics influence miR-122 requirements and proves that replication can occur without this miRNA, which has broad implications for how HCV tropism is maintained.
Filarial hydropneumothorax: a strange journey
Authors: Chakraborty Arkaprabha , Mukherjee Anindya , Talukdar Payel , Talukdar Arunansu
Published: November 2015

Filarial infection can have varied manifestations, but hydropneumothorax at presentation has not yet been reported. A 28-year-old man presented to our hospital with heaviness of the left chest for the past 10 days, which was preceded by a sudden, short stabbing pain in the left chest after straining. Chest X-ray revealed left-sided hydropneumothorax. A peripheral blood picture revealed significant eosinophilia. A pleural fluid report also showed eosinophilia and a few motile microfilaria ofWuchereria bancrofti. Microfilaria was also documented in peripheral blood. There was no evidence of other organ system involvement. The patient was diagnosed with ‘Filarial Hydropneumothorax’. After treatment with a temporary chest drain and oral diethylcarbamazine citrate, there was dramatic relief of symptoms and radiological improvement. The patient has been symptom free with no features of recurrence through 8 months of follow-up.
BET 3: Bedside ultrasound for the diagnosis of sternal fracture
Authors: Racine Samuel , Drake David
Published: November 2015

A shortcut review was carried out to establish whether ultrasound is an effective diagnostic tool for the diagnosis of sternal fractures. 27 papers were found of which 4 presented the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these best papers are tabulated. The clinical bottom line is that in patients with blunt thoracic injury and suspected isolated sternal fracture, ultrasound seems superior to conventional radiology to diagnose sternal fracture.
Multi-scale characterization of retention and shrinkage behaviour of four Australian clayey soils
Authors: Liu Xianfeng , Buzzi Olivier , Yuan Shengyang , Mendes Joao , Fityus Stephen
Published: November 2015

This paper presents a comprehensive experimental investigation on shrinkage and soil-water retention behaviour at macroscale and microscale of four natural Australian soils upon drying and wetting. Both reconstituted and intact states were tested. First, a comprehensive physicochemical characterization of the four soils was performed to provide a complete picture of the mineralogical composition and surface properties as well as different initial structure associated with reconstituted and intact states. Then, macroscale testing was conducted and complemented by microstructural analyses through mercury intrusion porosimetry (MIP) and scanning electron microscope (SEM) observations. These provided a comprehensive picture of the microfabric evolution of the soils tested along the drying–wetting path. All the experimental results were discussed in a coupled multi-scale manner.
Stream habitat connectivity in the Canadian Arctic: an on-site approach to design and construction
Authors: Courtice Gregory J. , Baki Abul Basar M. , Zhu David Z. , Cahill Christopher L. , Tonn William M.
Published: November 2015

We developed a successful on-site approach for design and construction of stream modifications that addressed challenging remote-site conditions of limited field data and available construction materials. Fish habitat connectivity enhancements were constructed within an Arctic headwater stream containing a naturally impassable cascade section with 13% slope, which was bypassed in a newly constructed channel at 5% slope with nature-like fishpass structures. Primary design considerations included (1) creating suitable hydraulic characteristics for fish passage in periods of high and low discharges; (2) reducing drop heights and creating unimpeded flow paths; (3) improving hydraulic complexity for a variety of stream habitats; and (4) salvaging and incorporating vegetation disturbed from construction activities into riparian and in-stream habitat structures. In high gradient reaches (2.5%–5%), we constructed boulder weirs, boulder chokes, and deflection boulders to overcome migration impediments. In medium gradient reaches (1.5–2.5%), rock ramps, boulder chokes, and deflection boulders were constructed to control hydraulic characteristics to ensure an unimpeded flow path, suitable hydraulic complexity, and resting zones. At lower gradients (<1.5%), we incorporated a softer approach using riparian vegetation and in-stream woody debris to ensure a similar quality of fish habitat as created in the higher gradient reaches. Initial hydraulic responses to the modifications indicated this reconstructed channel provided suitable hydraulic and habitat characteristics for habitat connectivity throughout the entire stream. Our findings advance understanding of headwater stream hydraulics in the Canadian Arctic and will assist in designing future stream restoration and fish habitat compensation projects on small and remote systems. This case study supports the feasibility of successfully constructing future habitat compensation projects in challenging remote environments when using an on-site, adaptive design and construction approach.
Re-evaluation of the historic Canadian fossil Bathygnathus borealis from the Early Permian of Prince Edward Island
Authors: Brink Kirstin S. , Maddin Hillary C. , Evans David C. , Reisz Robert R.
Published: November 2015

The holotype and only known specimen of Bathygnathus borealis is a partial snout with maxillary dentition of a presumed sphenacodontid from the Lower Permian (Artinskian 283–290 Ma) redbeds of Prince Edward Island, Canada. Due to its incomplete nature, assessment of the taxon’s systematic position within a cladistic analysis had never been performed. However, recent recognition of the phylogenetic utility of tooth characters in sphenacodontids now allows for a modern phylogenetic evaluation of B. borealis. Results show that B. borealis is the sister taxon of Dimetrodon grandis, which is supported by dental characters: crowns with mesial and distal denticles and roots elongate, lacking plicidentine. An autapomorphy of B. borealis is the large facial exposure of the septomaxilla. As Bathygnathus has priority over Dimetrodon in the scientific literature, we suggest a reversal of precedence is required to preserve the familiar name Dimetrodon and to maintain universality, thus recognizing the new species Dimetrodon borealis.
The Markov theorems for spatial graphs and handlebody-knots with Y-orientations
Authors: Ishii Atsushi
Published: November 2015

We establish the Markov theorems for spatial graphs and handlebody-knots. We introduce an IH-labeled spatial trivalent graph and develop a theory on it, since both a spatial graph and a handlebody-knot can be realized as the IH-equivalence classes of IH-labeled spatial trivalent graphs. We show that any two orientations of a graph without sources and sinks are related by finite sequence of local orientation changes preserving the condition that the graph has no sources and no sinks. This leads us to define two kinds of orientations for IH-labeled spatial trivalent graphs, which fit a closed braid, and is used for the proof of the Markov theorem. We give an enhanced Alexander theorem for orientated tangles, which is also used for the proof.
Keypoints-Based Image Passive Forensics Method for Copy-Move Attacks
Authors: Wang Xiaofeng , He Guanghui , Tang Chao , Han Yali , Wang Shangping
Published: November 2015

A novel image passive forensics method for copy-move forgery detection is proposed. The proposed method combines block matching technology and feature point matching technology, and breaks away from the general framework of the visual feature-based approach that used local visual feature such as SIFT and followed by a clustering procedure to group feature points that are spatially close. In our work, image keypoints are extracted using Harris detector, and the statistical features of keypoint neighborhoods are used to generate forensics features. Then we proposed a new forensics features matching approach, in which, a region growth technology and a mismatch checking approach are developed to reduce mismatched keypoints and improve detected accuracy. We also develop a duplicate region detection method based on the distance frequency of corresponding keypoint pairs. The proposed method can detect duplicate regions for high resolution images. It has higher detection accuracy and computation efficiency. Experimental results show that the proposed method is robust for content-preserving manipulations such as JPEG compression, gamma adjustment, filtering, luminance enhancement, blurring, etc.
An O(n3) algorithm for sorting signed genomes by reversals, transpositions, transreversals and block-interchanges
Authors: Yu Shuzhi , Hao Fanchang , Leong Hon Wai
Published: November 2015

We consider the problem of sorting signed permutations by reversals, transpositions, transreversals, and block-interchanges. The problem arises in the study of species evolution via large-scale genome rearrangement operations. Recently, Hao et al. gave a 2-approximation scheme called genome sorting by bridges (GSB) for solving this problem. Their result extended and unified the results of (i) He and Chen — a 2-approximation algorithm allowing reversals, transpositions, and block-interchanges (by also allowing transversals) and (ii) Hartman and Sharan — a 1.5-approximation algorithm allowing reversals, transpositions, and transversals (by also allowing block-interchanges). The GSB result is based on introduction of three bridge structures in the breakpoint graph, the L-bridge, T-bridge, and X-bridge that models goodreversal, transposition/transreversal, and block-interchange, respectively. However, the paper by Hao et al. focused on proving the 2-approximation GSB scheme and only mention a straightforward [Formula: see text] algorithm. In this paper, we give an [Formula: see text] algorithm for implementing the GSB scheme. The key idea behind our faster GSB algorithm is to represent cycles in the breakpoint graph by their canonical sequences, which greatly simplifies the search for these bridge structures. We also give some comparison results (running time and computed distances) against the original GSB implementation.
Indirect (source-free) integration method. II. Self-force consistent radial fall
Authors: Ritter Patxi , Aoudia Sofiane , Spallicci Alessandro D. A. M. , Cordier Stéphane
Published: November 2015

We apply our method of indirect integration, described in Part I, at fourth order, to the radial fall affected by the self-force (SF). The Mode-Sum regularization is performed in the Regge–Wheeler gauge using the equivalence with the harmonic gauge for this orbit. We consider also the motion subjected to a self-consistent and iterative correction determined by the SF through osculating stretches of geodesics. The convergence of the results confirms the validity of the integration method. This work complements and justifies the analysis and the results appeared in [Int. J. Geom. Meth. Mod. Phys. 11 (2014) 1450090].
Epitaxial Growth of Strain-Induced Ferromagnetic LaCoO3 Thin Films by Simple Sol–Gel Technique
Authors: Liu Haifeng , Guo Yuqiao , Xie Ruishi , Ma Guohua
Published: November 2015

LaCoO3 (LCO) epitaxial films were grown on (001) LaAlO3 (LAO) substrates by the simple sol–gel technique. X-ray diffraction (XRD) and the cross-section transmission electron microscope (TEM) measurements indicate that single-phase (001) oriented LCO epitaxial films with biaxial compressive strain and elongated distortion of CoO6 octahedrons were grown on (001) LAO successfully. The epitaxial relationship between the LCO film and the LAO substrate is confirmed to be (001)[Formula: see text] and [100][Formula: see text]. It is also found that LCO grown on LAO has a larger mean Co–O bond length and unit-cell size, compared with those of polycrystalline film. In addition, the magnetic characterization shows that LCO epitaxial film exhibits an obvious ferromagnetic (FM) transition at [Formula: see text][Formula: see text]K, which is different from the nonmagnetic ground state of polycrystalline LCO. Combined with the structural analyses, it reveals that the strain-induced ferromagnetism observed in LCO epitaxial film originates from an increase of the mean Co–O bond length and a suppression of the CoO6 octahedral rotations, which can stabilize higher spin state of Co[Formula: see text] by a decrease of the [Formula: see text] gap energy.
Synthesis of Novel Hollow Copper Oxide Micro-Flowers Assembled by Nanoparticles and Their Improved Catalytic Performances for the Synthesis of Organosilane
Authors: Che Hongwei , Liu Aifeng , Mu Jingbo , Zhang Xiaoliang
Published: November 2015

In this work, novel sisal-like hollow CuO micro-flowers were synthesized via a facile solvothermal reaction followed by calcination. The flower-like shells of hollow CuO are constructed by irregular petals interweaving each other, which are composed of aggregated nanoparticles with sizes of ca. 18[Formula: see text]nm. It was found that the flower-like morphology of the as-synthesized CuO products can be controlled via finely tuning the solvothermal reaction time. When used as catalysts for the synthesis of organosilane, the obtained hollow CuO micro-flowers exhibit better catalytic performances than the commercial CuO powders. Superior catalytic performances are due to the hollow and flower-like structures of the as-synthesized CuO products, which can promote the synthetic reaction for the organosilane, that is, the gas–solid contacting reaction occurred among the reaction gas, solid silicon powders and CuO catalysts. Our work will be helpful to design and develop the novel Cu-based nanocatalysts for the synthesis of organosilane.
The C-numerical range of perturbations matrix polynomials
Authors: Jahanshahi Yaser , Yousefi Bahmann
Published: November 2015

In this paper, the [Formula: see text]-radius stability of a matrix polynomial [Formula: see text] relative to a domain [Formula: see text] of the complex plane and its relation with the [Formula: see text]-numerical range of [Formula: see text] are investigated. By using an expression of the [Formula: see text]-radius stability, we obtain a lower bound which involves the distance of [Formula: see text] from the connected components of the [Formula: see text]-numerical range of [Formula: see text].
Collagen-biomorphic porous carbon nanofiber monoliths: Biosilicification-assisted sustainable synthesis and application in Li-S battery
Authors: Hu Wen , Shen Tao , Hou Hongying , Gan Guoyou , Zheng Biju , Li Fengxian , Yi Jianhong
Published: November 2015

Monolithic carbon has been synthesized via a sustainable biomimetic route utilizing intrafibrillar silicified collagen sponge as precursor and morphogenesis template. The mineralized silica in the biohybrid prevents collapse of the carbon during pyrolysis. Upon biosilica removal results show that the carbon monoliths inherit the porous fiber structure of the mother collagen. The carbon nanofiber framework facilitates the construction of a high electrical conductive pathway, while the internal spaces developed among the intertwined fibrillar network and pores within nanofiber walls offer room for sulfur storage. The as-obtained carbon-sulfur cathode exhibits an accessible discharge capacity approaching 800[Formula: see text]mAh g[Formula: see text] in Li–S battery.
Monochromatic connectivity and graph products
Authors: Mao Yaping , Wang Zhao , Yanling Fengnan , Ye Chengfu
Published: November 2015

The concept of monochromatic connectivity was introduced by Caro and Yuster. A path in an edge-colored graph is called a monochromatic path if all the edges on the path are colored the same. An edge-coloring of [Formula: see text] is a monochromatic connection coloring ([Formula: see text]-coloring, for short) if there is a monochromatic path joining any two vertices in [Formula: see text]. The monochromatic connection number, denoted by [Formula: see text], is defined to be the maximum number of colors used in an [Formula: see text]-coloring of a graph [Formula: see text]. In this paper, we study the monochromatic connection number on the lexicographical, strong, Cartesian and direct products and present several upper and lower bounds for these products of graphs.
Improving Handwritten Arabic Character Recognition by Modeling Human Handwriting Distortions
Authors: Shatnawi Maad , Abdallah Sherief
Published: November 2015

Handwritten Arabic character recognition systems face several challenges, including the unlimited variation in human handwriting and the unavailability of large public databases of handwritten characters and words. The use of synthetic data for training and testing handwritten character recognition systems is one of the possible solutions to provide several variations for these characters and to overcome the lack of large databases. While this can be using arbitrary distortions, such as image noise and randomized affine transformations, such distortions are not realistic. In this work, we model real distortions in handwriting using real handwritten Arabic character examples and then use these distortion models to synthesize handwritten examples that are more realistic. We show that the use of our proposed approach leads to significant improvements across different machine-learning classification algorithms.
Q&A: Redefining Architectures
Authors: Hoffmann Leah
Published: November 2015

Mary Jane Irwin on building advanced circuits, special processors, and a hardware description language, while advocating for women in computer science.
Dynamic Behaviors of a Leslie-Gower Ecoepidemiological Model
Authors: Kang Aihua , Xue Yakui , Fu Jianping
Published: November 2015

A Leslie-Gower ecoepidemic model with disease in the predators is constructed and analyzed. The total population is subdivided into three subclasses, namely, susceptible predator, infected predator, and prey population. The positivity, boundness of solutions, and the existence of the equilibria are studied, and the sufficient conditions of local asymptotic stability of the equilibria are obtained by the Routh-Hurwitz criterion. We analyze the global stability of the interior equilibria by using Lyapunov functions. It is observed that a Hopf bifurcation may occur around the interior equilibrium. At last, numeric simulations are performed in support of the feasibility of the main result.
A Fourier Continuation Method for the Solution of Elliptic Eigenvalue Problems in General Domains
Authors: Bruno Oscar P. , Elling Timothy , Sen Ayon
Published: November 2015

We present a new computational method for the solution of elliptic eigenvalue problems with variable coefficients in general two-dimensional domains. The proposed approach is based on use of the novel Fourier continuation method (which enables fast and highly accurate Fourier approximation of nonperiodic functions in equispaced grids without the limitations arising from the Gibbs phenomenon) in conjunction with an overlapping patch domain decomposition strategy and Arnoldi iteration. A variety of examples demonstrate the versatility, accuracy, and generality of the proposed methodology.
Effect of Fluctuating Surface Heat and Mass Flux on Natural Convection Flow along a Vertical Flat Plate
Authors: Hussain Sharmina , Roy Nepal C. , Hossain Md. Anwar , Saha Suvash C.
Published: November 2015

An investigation has been carried on double diffusive effect on boundary layer flow due to small amplitude oscillation in surface heat and mass flux. Extensive parametric simulations were performed in order to elucidate the effects of some important parameters, that is, Prandtl number, Schmidt number, and Buoyancy ratio parameter on flow field in conjunction with heat and mass transfer. Asymptotic solutions for low and high frequencies are obtained for the conveniently transformed governing coupled equations. Solutions are also obtained for wide ranged value of the frequency parameters. Comparisons between the asymptotic and wide ranged values are made in terms of the amplitudes and phases of the shear stress, surface heat transfer, and surface mass transfer. It has been found that the amplitudes and phase angles obtained from asymptotic solutions are found in good agreement with the finite difference solutions obtained for wide ranged value of the frequency parameter.
Microbial Cellulose Production from Bacteria Isolated from Rotten Fruit
Authors: Rangaswamy B. E. , Vanitha K. P. , Hungund Basavaraj S.
Published: November 2015

Microbial cellulose, an exopolysaccharide produced by bacteria, has unique structural and mechanical properties and is highly pure compared to plant cellulose. Present study represents isolation, identification, and screening of cellulose producing bacteria and further process optimization. Isolation of thirty cellulose producers was carried out from natural sources like rotten fruits and rotten vegetables. The bacterial isolates obtained from rotten pomegranate, rotten sweet potato, and rotten potato were identified asGluconacetobactersp. RV28,Enterobactersp. RV11, andPseudomonassp. RV14 through morphological and biochemical analysis. Optimization studies were conducted for process parameters like inoculum density, temperature, pH, agitation, and carbon and nitrogen sources usingGluconacetobactersp. RV28. The strain produced 4.7 g/L of cellulose at optimum growth conditions of temperature (30°C), pH (6.0), sucrose (2%), peptone (0.5%), and inoculum density (5%). Characterization of microbial cellulose was done by scanning electron microscopy (SEM).
Solving the Telegraph and Oscillatory Differential Equations by a Block Hybrid Trigonometrically Fitted Algorithm
Authors: Ngwane F. F. , Jator S. N.
Published: November 2015

We propose a block hybrid trigonometrically fitted (BHT) method, whose coefficients are functions of the frequency and the step-size for directly solving general second-order initial value problems (IVPs), including systems arising from the semidiscretization of hyperbolic Partial Differential Equations (PDEs), such as the Telegraph equation. The BHT is formulated from eight discrete hybrid formulas which are provided by a continuous two-step hybrid trigonometrically fitted method with two off-grid points. The BHT is implemented in a block-by-block fashion; in this way, the method does not suffer from the disadvantages of requiring starting values and predictors which are inherent in predictor-corrector methods. The stability property of the BHT is discussed and the performance of the method is demonstrated on some numerical examples to show accuracy and efficiency advantages.