bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biological control in Honduras.
Authors: Trabanino R. , Pitty A. , Cave R. D. 
Published: December 2019

Abstract

Prospecting for natural enemies and microbial control agents has been an important activity in Honduras since 1968, with as major projects the inventories of parasitoids of diamondback moth, striped grass looper, fall armyworm, Mexican cabbage butterfly, dipteran leaf miners, diaspids, coccids and aleurodids. The creation of the Center for Biological Control in Central America within the Zamorano University in 1989 was the starting point of teaching, research and the implementation of classical, augmentative and conservation biocontrol in the region. The Center trains hundreds of students from 21 countries each year and thesis work by its students results in a lot of knowledge about natural enemies, microbial agents and their mass-production methods. In 1990, introduction of phytophagous weevils for classical control of water hyacinth was a success. Microbial control of diamondback moth with a virus was tested in the 1990s, followed by the development and production of several fungus-, virus- and nematode-based formulations for control of pests and diseases. Trichoderma, Metarhizium, Isaria, Lecanicillium and Beauveria are now registered as commercial products and are also used in other countries in the region. In 2008 a successful project was started to reduce agrochemical use in vegetables, consisting of local mass rearing of several predators for augmentative control of thrips, aphids, mites and whitefly, and training of hundreds of farmers. A similar successful project concerned training courses on biocontrol of the sweet potato weevil for more than 5,000 farmers in the poorest area of the country.
Biological control in Jamaica.
Authors: Sherwood M. A. , Lenteren J. C. van 
Published: December 2019

Abstract

Jamaica has a rich history of successful biological control of more than 25 pests of economic and quarantine importance. Approximately 14 classical, 13 natural and six augmentative biocontrol programmes were recorded, as well as two fortuitous introductions. The programmes concerned control of key pests on: (i) citrus, such as citrus blackfly, citrus red scale, cottony cushion scale, citrus root weevils, brown citrus aphid, lime swallowtail butterfly and Asian citrus psyllid; (ii) sugarcane, mainly sugarcane borers; (iii) banana, the banana weevil; (iv) cocoa, the cocoa thrips; (v) coconut, with coconut scale, two aphid species and red palm mite; (vi) sweet potato, sweet potato weevil; (vii) crucifers, with diamondback moth and cabbage looper; (viii) coffee, with coffee berry borer and coffee leaf miner; (ix) residential fruit tree crops and ornamentals, with pink hibiscus mealybug and ensign scale; (x) papaya, with papaya mealybug and citrus root weevil; and (xi) onion and scallion, with beet armyworm. Biocontrol agents used were species of parasitoids, predatory beetles and mites, nucleopolyhedroviruses, and entomopathogenic fungi and nematodes. Jamaica served as a provider of biocontrol agents for the Caribbean and Hawaii. A biocontrol facility is currently being built to develop control methods for endemic and invasive pests.
Biological control in Paraguay.
Authors: Cabral Antúnez C. C. , Resquín Romero G. , Gómez López V. A. 
Published: December 2019

Abstract

Biological control in Paraguay started in the 1980s with the use of a baculovirus for augmentative biocontrol of the soybean caterpillar and application of parasitoids to control the sugarcane borer. Since 2000, organic production has stimulated use of biocontrol. Also in 2000, large-scale prospecting for natural enemies and microbial control agents in crops such as cotton, maize, bean, peanut, sesame, soybean and sugarcane was initiated. Many natural enemies found during these prospecting activities are currently used in conservation biocontrol programmes. Several entomopathogenic and phytopathogenic agents have been registered and are used in Paraguay.
Cassava: pests and diseases.
Authors: Lebot V. 
Published: December 2019

Abstract

Cassava is attacked by numerous pests and diseases that cause significant losses, especially in South America, its area of origin. Some pathogens attack only the stakes and invade the vascular system, constituting primary sources of infection, while others attack only foliar or root tissues. This chapter provides information on the various nematode, arthropod and insect pests and bacterial, fungal and viral pathogens affecting cassava and the importance of integrated methods in the management of thsese pests and diseases.
Aroids: breeding and genetics.
Authors: Lebot V. 
Published: December 2019

Abstract

Modern aroid (Alocasia, Amorphophallus, Colocasia, Cyrtosperma and Xanthosoma) production is becoming intensive and oriented to the market, which requires cheap, healthy and high-quality products. The aim of taro breeding is to create genotypes that are high yielding, with corms of good eating quality, resistant to diseases, tolerant to pests and well adapted to specific environments (paddy or dryland conditions). This chapter discusses the breeding objectives and criteria, sexual reproduction and sterility, crossing techniques and true seed production, selection methods and programmes, heritability of major traits, and genotype × environment interactions of aroids. The use of related species, polyploidy breeding, use of molecular markers, transgenic technologies, and germplasm conservation are also described.
Aroids: agronomy.
Authors: Lebot V. 
Published: December 2019

Abstract

Aroids can be grown throughout the year in the wet tropics. They are best adapted to high temperatures, a moist environment and high humidity. Evenly distributed rainfall, between 200 and 300 mm/month, is ideal for optimum growth and production. Irrigation is, however, necessary for taro and swamp taro (Cyrtosperma merkusii) in low rainfall areas, while cocoyam (Xanthosoma sagittifolium), giant taro (Alocasia macrorrhizos) and elephant foot yam (Amorphophallus paeoniifolius) are more drought tolerant. For all species, and for a given genotype, the time needed to reach maturity varies according to temperature, sunlight and water availability. This chapter discusses the agronomy of aroids, including the seed systems and propagule selection, soil preparation, plant densities and crop establishment, intercropping, weeding, fertilizer application, nutrient disorders, and harvesting.
Aroids: postharvest quality and marketing.
Authors: Lebot V. 
Published: December 2019

Abstract

Cocoyam, taro and other aroids (Alocasia, Amorphophallus and Cyrtosperma) have much potential in terms of fresh and processed products and are, in fact, industries with considerable expansion potential, especially as biofunctional foods. Taro is already processed and prepared into many consumable and diverse forms. Corms may be roasted, baked, boiled, steamed or fried. They may be processed into fresh or fermented paste, canned corm portions, flour, beverage, chips and flakes. The leaves, petioles, stolons and inflorescences are also consumed and are steamed or boiled. This chapter describes the chemical composition, physiological disorders in freshly stored corms, marketing, quality standards, storage methods, traditional processing techniques, and industrial processing of aroids.
Bilinear Forms and Dark-Dark Solitons for the Coupled Cubic-Quintic Nonlinear Schrödinger Equations with Variable Coefficients in a Twin-Core Optical Fiber or Non-Kerr Medium*
Authors: Chu Mei-Xia , Tian Bo , Yuan Yu-Qiang , Zhang Ze , Tian He-Yuan 
Published: December 2019

Abstract

Twin-core optical fibers are applied in such fields as the optical sensing and optical communication, and propagation of the pulses, Gauss beams and laser beams in the non-Kerr media is reported. Studied in this paper are the coupled cubic-quintic nonlinear Schrödinger equations with variable coefficients, which describe the effects of quintic nonlinearity for the ultrashort optical pulse propagation in a twin-core optical fiber or non-Kerr medium. Based on the integrable conditions, bilinear forms are derived, and dark-dark soliton solutions can be constructed in terms of the Gramian via the Kadomtsev-Petviashvili hierarchy reduction. Propagation and interaction of the dark-dark solitons are presented and discussed through the graphic analysis. With different values of the delayed nonlinear response effect b(z), where z represents direction of the propagation, the linear- and parabolic-shaped one dark-dark soltions can be derived. Interactions between the parabolic- and periodic-shaped two dark-dark solitons are presented with b(z) as the linear and periodic functions, respectively. Directions of velocities of the two dark-dark solitons vary with z and the amplitudes of the solitons remain unchanged can be observed. Interactions between the two dark-dark solitons of different types are displayed, and we observe that the velocity of one soliton is zero and direction of the velocity of the other soliton vary with z. We find that those interactions are elastic.
An Optimal Analysis for 3D Flow of Prandtl Nanofluid with Convectively Heated Surface
Authors: Ullah Malik Zaka , Alghamdi Metib 
Published: December 2019

Abstract

In this paper, the magnetohydrodynamic 3D flow of Prandtl nanoliquid subject to convectively heated extendable surface has been discussed. A linear stretching surface makes the flow. Thermophoretic and Brownian motion impacts are explored. Heat transfer for convective procedure is considered. Prandtl liquid is taken electrically conducted through applied magnetic field. Suitable non-dimensional variables lead to strong nonlinear ordinary differential system. The obtained nonlinear differential systems are solved through optimal homotopic technique. Physical quantities like skin friction coefficients and Nusselt number are explored via plots. It is observed that effects of Hartman parameter and Biot number on temperature and concentration are quite similar. Both temperature and concentration are enhanced for larger values of Hartman parameter and Biot number.
Quantum magnetometry using two-stroke thermal machines
Authors: Bhattacharjee Sourav , Bhattacharya Utso , Niedenzu Wolfgang , Mukherjee Victor , Dutta Amit 
Published: December 2019

Abstract
The precise estimation of small parameters is a challenging problem in quantum metrology. Here, we introduce a protocol for accurately measuring weak magnetic fields using a two-level magnetometer, which is coupled to two (hot and cold) thermal baths and operated as a two-stroke quantum thermal machine. Its working substance consists of a two-level system (TLS), generated by an unknown weak magnetic field acting on a qubit, and a second TLS arising due to the application of a known strong and tunable field on another qubit. Depending on this field, the machine may either act as an engine or a refrigerator. Under feasible conditions, determining this transition point allows to reduce the relative error of the measurement of the weak unknown magnetic field by the ratio of the temperatures of the colder bath to the hotter bath.
Nonreciprocal wave propagation and parametric amplification of bulk elastic waves in nonlinear anisotropic materials
Authors: Zakeri Mahsa , Keller Scott M , Wang Yuanxun Ethan , Lynch Christopher S 
Published: December 2019

Abstract
Parametric amplification of an elastic wave and a framework for using elastic waves that could enable a new generation of high performance, low noise acoustic amplifiers, mixers and circulators are presented. Using a novel approach with nonlinear materials produces highly desirable non-reciprocal characteristics. Parametric amplification of a weak elastic signal wave is achieved by an elastic pump wave of higher intensity. By careful selection of material orientation together with precise excitation of signal and pump waves, ‘up frequency conversion’ is suppressed and selective amplification of the elastic signal wave occurs at its original frequency. In addition, a general mathematical framework is developed and used for analytical studies of coupled wave equations in nonlinear anisotropic materials. The results obtained from the analytical studies are verified using a finite element implementation.
An algorithm for Bragg coherent x-ray diffractive imaging of highly strained nanocrystals
Authors: Wang Ziyi , Gorobtsov Oleg , Singer Andrej 
Published: December 2019

Abstract
By using phase retrieval, Bragg coherent diffractive imaging (BCDI) allows tracking of three-dimensional displacement fields inside individual nanocrystals. Nevertheless, during structural phase transformations, significant strains (1% and higher) are common, and BCDI fails due to the Bragg peak distortions. Here we present and advanced BCDI algorithm enabling imaging three-dimensional strain fields in highly strained crystals with separated structural phases. We test the algorithm on particles simulated to undergo a structural phase transformation. While the conventional algorithms fail in unambiguously reconstructing the phase morphology, our algorithm correctly retrieves the morphology of coexistent phases with a strain difference of 1%. The key novelty is the simultaneous reconstruction of multiple scans of the same nanoparticle at snapshots through the phase transformations. The algorithm enables visualizing phase transformations in nanoparticles of lithium-ion, sodium-ion nanoparticles, and other nanoparticulate materials in working conditions (operando).
Resolving non-homogeneous linear differential equations using the undetermined method coefficients and variation of parameters by means of GeoGebra
Authors: Funes Jorge Olivares , Kari Elvis Valero 
Published: December 2019

Abstract
In this paper, it is shown how non-homogeneous linear differential equations, especially those of the second order, are solved by means of GeoGebra applets, This is done by indeterminate coefficient methods and variation of parameters, in the course of differential equations for engineering students of the University of Antofagasta in Chile. The use of free software GeoGebra has been increasing in the teaching of mathematics, mainly in non-homogeneous linear differential equations, because it facilitates the teaching and learning process
Modeling the process of attracting foreign investment in the Russian economy
Authors: MGaleeva G 
Published: December 2019

Abstract
In the paper, on the basis of an assessment of the development of the Russian economy, the sectors most in need of an investment are identified, taking into account the depreciation rate of basic production assets. Depreciation of fixed assets reflects the demand for investment in order to modernize and reconstruct production. Based on the data of the Federal State Statistics Service of Russia, a rating of economic sectors in terms of the degree of depreciation of fixed assets at the end of the year by type of economic activity for 2013-2018 is built. In addition, the paper presents a model for predicting the inflow of foreign direct investment in Russia, developed using the classical approach to estimating linear regression criteria, which is based on the least squares method (OLS). In compiling this regression model, the applied software package for econometric modeling GRETL (GNU Regression, Econometrics and Time-series Library) was used to predict the inflow of foreign investment. Forecasting the inflow of foreign investment in the Russian Federation is aimed at solving the following tasks: to determine the most competent direction of investment policy and activity using forecast estimates, as well as to assess the country’s investment attractiveness. However, a significant role in predicting this indicator is played by the determination of factors that have an impact on the future volume of foreign investment. In addition, the analysis of foreign investments, depending on the influence of various factors, can tell about those or other motives that guide foreign investors when investing their own capital.
On the two-component generalization of the (2+1)-dimensional Davey-Stewartson I equation
Authors: Serikbayev Nurzhan , Nugmanova Gulgassyl , Myrzakulov Ratbay 
Published: December 2019

Abstract
The geometric-gauge equivalent of the famous Ishimori spin equation is the (2+1)-dimensional Davey-Stewartson equation, which in turn is one of the (2+1)-dimensional generalizations of the nonlinear Schrodinger equation. Multicomponent generalization of nonlinear integrable equations attract considerable interest from both physical and mathematical points of view. In this paper, the two-component integrable generalization of the (2+1)-dimensional Davey-Stewartson I equation is obtained based on its one-component representation, and the corresponding Lax representation is also obtained.
Cosmological Yang-Mills model with k-essence
Authors: Razina O V , Tsyba P Yu , Myrzakulov R , Meirbekov B , Shanina Z 
Published: December 2019

Abstract
We considered the f(R) model of gravity with the Yang-Mills field and k-essence in four dimensions, together with the homogeneous, isotropic and flat Friedmann-Robertson-Walker universe. For this model we found equations of motion, a solution for a scale factor, a scalar field, a scalar potential is reconstructed, we studied the slow roll parameters. For the model under consideration, the of slow roll parameters satisfy the region of the inflationary stage. For later times was found the equation of state parameter ω, the deceleration parameter q the value of which corresponds to the accelerated expansion of the universe. Our model allows you to get an accelerated expansion of the universe in the inflationary period. Over time, the field decreases, rolls off slowly, viscosity has a lesser effect, and the universe leaves the inflationary regime, which shows the exponential dynamics of changes in the law of expansion of the universe.
Geometric characteristics for Camassa–Holm equation
Authors: Mussatayeva Assem , Myrzakulov Nurgissa , Altaibayeva Aziza 
Published: December 2019

Abstract
One of the actual problems of mathematical physics is to relate differential geometry and nonlinear differential equation. Research in this direction is very important, as the results are a theoretical and practical application. In this paper, we investigate the Camassa-Holm equation. It is well known that the integrable nonlinear Camassa-Holm equation play an important role in the study of wave propagation. We present the relationship between Camassa-Holm equation and soliton surfaces. The rst and second fundamental forms, surface area and curvature for Camassa-Holm equation are found.
Exponential variational integrators for the dynamics of multibody systems with holonomic constraints
Authors: Kosmas Odysseas 
Published: December 2019

Abstract
We here explore a geometric integrator scheme that is determined by a discretization of a variational principle using a higher-order Lagrangian that uses exponential type of interpolation functions. The resulting exponential variational integrators are here extended to conservative mechanical systems with constraints. To do so we first present continuous Euler-Lagrangian equations with holonomic constraints and then mimic the process for the discrete case. The resulting schemes are then tested to a typical dynamical multibody system with constraints, i.e the double pendulum showing the good long-time behavior when compared to other traditional methods.
A look to differential
Authors: Gómez A 
Published: December 2019

Abstract
This paper reveals results of a research related to the presentation of the concept of differential for functions of a variable, from some calculus textbooks. Given that the concept of differential is closely linked to the concepts of derivative, integral and differential equation, the objective is to analyze the different ways of presenting the concept from those instances, in order to determine whether the presentation facilitates its understanding. The research follows a qualitative methodology based on a bibliographic review and conceptual didactic analysis, proceeding from content analysis corresponding to the notion of differential. It was found that the concept of differential in textbooks is presented in a geometric context, as an increment of a variable and as a function, dispossessed of its arithmetic meaning, being impossible to suppress the concept in the formal construction of the calculus.
Metaphors in textbooks of differential equations
Authors: Gómez A 
Published: December 2019

Abstract
This research is an approach to the study of metaphors in the teaching of differential equations, present in textbooks. The objective is to analyse the cognitive metaphors that facilitate learning in the search for the solution of homogeneous linear differential equations. The methodology used was content analysis applied to a subjective sample of four university texts. The analysis allowed to find that the texts that use linear algebra make it easier the teaching of differential equations, and it is concluded that the metaphors from linear algebra are fundamentals in the teaching of linear differential equations, the basic concept facilitates the learning for the construction of the general solution of linear differential equations.
Large cells cancer volumetry in chest computed tomography pulmonary images
Authors: Huérfano Y , Vera M , Gelvez-Almeida E , Vera M I , Valbuena O , Salazar-Torres J 
Published: December 2019

Abstract
Lung cancer is the leading oncological cause of death in the world. As for carcinomas, they represent between 90% and 95% of lung cancers; among them, non-small cell lung cancer is the most common type and the large cell carcinoma, the pathology on which this research focuses, is usually detected with the computed tomography images of the thorax. These images have three big problems: noise, artifacts and low contrast. The volume of the large cell carcinoma is obtained from the segmentations of the cancerous tumor generated, in a semi-automatic way, by a computational strategy based on a combination of algorithms that, in order to address the aforementioned problems, considers median and gradient magnitude filters and an unsupervised grouping technique for generating the large cell carcinoma morphology. The results of high correlation between the semi-automatic segmentations and the manual ones, drawn up by a pulmonologist, allow us to infer the excellent performance of the proposed technique. This technique can be useful in the detection and monitoring of large cell carcinoma and if it is considering this kind of computational strategy, medical specialists can establish the clinic or surgical actions oriented to address this pulmonary pathology.
How to divide the water level and danger zone of mountain floods along the river in the hilly area
Authors: Yan Chengshan , Wang Weilin , Zheng Congqi 
Published: December 2019

Abstract
With the precision of mountain flood disaster prevention work in the hilly area, the local key areas (villages and towns) in the hilly areas have become the focus of disaster prevention. This paper introduces analytical process of the flood control capacity of village along river, gives the calculating method of water level-river discharge relationship in control section, puts forward a feasible method of calculating the disaster water level and counting number of people in danger zone by point projection and judging point-line relationship. And this method is calculated by taking typical village along river for instance. The results show that this method can ascertain the household that is the weakest in the aspect of flood control capacity by combining field investigation and determine the relationship between households and different frequencies of flood water line, thus the flood control capacity of village along the river can be calculated accurately.