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In this paper, the nonlocal reverse space-time derivative nonlinear Schrödinger equation under nonzero boundary conditions is investigated using the Riemann–Hilbert (RH) approach. The direct scattering problem focuses on the analyticity, symmetries, and asymptotic behaviors of the Jost eigenfunctions and scattering matrix functions, leading to the construction of the corresponding RH problem. Then, in the inverse scattering problem, the Plemelj formula is employed to solve the RH problem. So the reconstruction formula, trace formulae, θ condition, and exact expression of the single-pole and double-pole solutions are obtained. Furthermore, dark–dark solitons, bright–dark solitons, and breather solutions of the reverse space-time derivative nonlinear Schrödinger equation are presented along with their dynamic behaviors summarized through graphical simulation. [ABSTRACT FROM AUTHOR]

Background: Chronic obstructive pulmonary disease (COPD) is an acknowledged contributor to universal fatality and morbidity. Using biomarkers to pinpoint its phenotypes is crucial, enabling individualized treatment and enhancing prognosis. Objective: Studying the steadiness of blood eosinophi1s in cases who experienced repeated hospital admissions for acute worsening of COPD during a year and its correlation to the treatment plan. Methods: A retrospective cohort study includes 270 COPD male patients with acute exacerbations. The patients were divided into three groups: fluctuating (ranges between ≥ 150 cells/ul and < 150 cells/ul), non-EOS (< 150 cells/ul), and Eosinophil (EOS) (≥ 150 cells/ul). Results: Most patients were in the fluctuating blood EOS group (53.3%). The median length of hospital stay was longer in the fluctuating group (5 days). There was a significant positive correlation between the number of exacerbations and both EOS count and EOS/WBCs. A higher eosinophilic count was associated with an increased risk of eosinophilic exacerbations. Most patients used steroids (higher in the EOS group, 61.6%). Conclusion: Blood eosinophilic count is promising for investigating acute COPD exacerbations. Peripheral blood eosinophilia is a relevant biomarker for directing the management of COPD exacerbations, including steroids. [ABSTRACT FROM AUTHOR]

This paper is devoted to prove the existence of continuous solutions for a nonlinear integral equation. Our existence theorem extends in a broad sense the analogous one obtained by L.T.P. Ngoc and N.T. Long. To this aim we first prove new variants of the Krasnosel'skii-Sadowskii and of the Krasnosel'skii-Däher fixed point theorems in Hausdorff locally convex topological vector spaces. These hybrid theorems improve some recently obtained results. Moreover a fixed point theorem for a multimap defined on a cartesian product subset of a Banach space is stated. [ABSTRACT FROM AUTHOR]

The Dbar dressing method is extended to study the focusing/defocusing nonlinear Schrödinger (NLS) equation with nonzero boundary condition. A special type of complex function is considered. The function is meromorphic outside an annulus with center 0 and satisfies a local Dbar problem inside the annulus. The theory of such function is extended to construct the Lax pair of the NLS equation with nonzero boundary condition. In this procedure, the relation between the NLS potential and the solution of the Dbar problem is established. A certain distribution for the Dbar problem is introduced to obtain the focusing/defocusing NLS equation and the conservation laws. [ABSTRACT FROM AUTHOR]

The boundary value problem for the focusing Kundu–Eckhaus equation with nonzero boundary conditions is studied by the Dbar dressing method in this work. A Dbar problem with non-canonical normalization condition at infinity is introduced to investigate the soliton solution. The eigenfunction of Dbar problem is meromorphic outside annulus with center 0, which is used to construct the Lax pair of the Kundu–Eckhaus equation with nonzero boundary conditions, which is a crucial step to further search for the soliton solution. Furthermore, the original nonlinear evolution equation and conservation law are obtained by means of choosing a special distribution matrix. Moreover, the N-soliton solutions of the focusing Kundu–Eckhaus equation with nonzero boundary conditions are discussed based on the symmetries and distribution. As concrete examples, the dynamic behaviors of the one-breather solution and the two-breather solution are analyzed graphically by considering different parameters. [ABSTRACT FROM AUTHOR]

Purpose of Review: Alpha-1 antitrypsin deficiency (AATD) is one of the most common genetic diseases that is associated with severe complications and yet remains underdiagnosed. The pulmonary symptoms of both AATD and asthma include cough, excessive sputum production, dyspnea, and wheezing. These symptoms overlap significantly leading to difficulty distinguishing between these two conditions and suspicion that there may be an overlap syndrome. We aim to discuss the pathophysiology, clinical manifestations, and treatment of both alpha-1 antitrypsin and asthma and how they may overlap. Recent Findings: Recent literature suggests that there is an association between asthma and AATD. This association has been hypothesized to be secondary to an imbalance of elastase and anti-elastase leading to a pro-inflammatory state in patients with AATD. Summary: This review serves to overview the pathophysiology, clinical manifestations, and treatment of alpha-1 antitrypsin, asthma, and the increasingly recognized intersection of the two, AATD-asthma overlap syndrome. [ABSTRACT FROM AUTHOR]

The incidence of neuroendocrine neoplasms and related carcinoid syndrome (CS) has markedly increased over the last decades and women seem to be more at risk than men for developing CS. Nevertheless, very few studies have investigated sex differences in clinical presentation and outcomes of CS. However, as per other tumours, sex might be relevant in influencing tumour localization, delay in diagnosis, clinical outcomes, prognosis and overall survival in CS. The present review was aimed at evaluating sex differences in CS, as they emerge from an extensive search of the recent literature. It emerged that CS occurs more frequently in female than in male patients with NENs and women seem to have a better prognosis and a slight advantage in overall survival and response to therapy. Moreover, the disease likely impacts differently the quality of life of men and women, with different psychological and social consequences. Nevertheless, sex differences, even if partially known, are deeply underestimated in clinical practice and data from clinical trials are lacking. There is urgent need to increase our understanding of the sex-related differences of CS, in order to define tailored strategies of management of the disease, improving both the quality of life and the prognosis of affected patients. [ABSTRACT FROM AUTHOR]

In this article, the inverse scattering transform is considered for the Gerdjikov–Ivanov equation with zero and non-zero boundary conditions by a matrix Riemann–Hilbert (RH) method. The formula of the soliton solutions is established by Laurent expansion to the RH problem. The method we used is different from computing solution with simple poles since the residue conditions here are hard to be obtained. The formula of multiple soliton solutions with one high-order pole and N multiple high-order poles are obtained, respectively. The dynamical properties and characteristic for the high-order pole solutions are further analyzed. [ABSTRACT FROM AUTHOR]

We study the Cauchy problem of the focusing Hirota equation with fastly decay initial value at infinity via Riemann-Hilbert (RH) approach. The Jost function and scattering matrix related to the initial value are obtained by spectral analysis, and their analytical, asymptotic and symmetric properties are analyzed. The solution of the Hirota equation is derived by solving the corresponding RH problem, which contains two cases of scattering data with single zeros and double zeros. The general form of solutions with no reflection potential is obtained. The two types of the discrete spectrum are selected for the purpose of comparing the influence of different eigenvalues on solution propagation behavior. [ABSTRACT FROM AUTHOR]

In this work, we use the inverse scattering transform method to consider the focusing Kundu–Eckhaus (KE) equation with nonzero background (NZBG) at infinity. Based on the analytical, symmetric, asymptotic properties of eigenfunctions, the inverse problem is solved via a matrix Riemann–Hilbert problem (RHP). The general multi-pole solutions are given in terms of the solution of the associated RHP. And the formula of the N simple-pole soliton solutions are obtained, too. We show that the Peregrine's rational solution can be viewed as some appropriate limit of the simple-pole soliton solutions at branch point. Furthermore, by taking some other proper limits, the two and three simple-pole soliton solutions can yield to the double- and triple-pole solutions for focusing KE equation with NZBG. The effect of the parameter β , characterizing the strength of the non-Kerr (quintic) nonlinear and the self-frequency shift effect, and some typical collisions between solutions of focusing KE equation are graphically displayed. [ABSTRACT FROM AUTHOR]

In this paper, we report a rigorous theory of the inverse scattering transforms (ISTs) for the derivative nonlinear Schrödinger (DNLS) equation with both zero boundary conditions (ZBCs) and nonzero boundary conditions (NZBCs) at infinity and double zeros of analytical scattering coefficients. The scattering theories for both ZBCs and NZBCs are addressed. The direct scattering problem establishes the analyticity, symmetries, and asymptotic behaviors of the Jost solutions and scattering matrix, and properties of discrete spectra. The inverse scattering problems are formulated and solved with the aid of the matrix Riemann–Hilbert problems, and the reconstruction formulae, trace formulae and theta conditions are also posed. In particular, the IST with NZBCs at infinity is proposed by a suitable uniformization variable, which allows the scattering problem to be solved on a standard complex plane instead of a two-sheeted Riemann surface. The reflectionless potentials with double poles for the ZBCs and NZBCs are both carried out explicitly by means of determinants. Some representative semi-rational bright–bright soliton, dark–bright soliton, and breather–breather solutions are examined in detail. These results and idea can also be extended to other types of DNLS equations such as the Chen–Lee–Liu-type DNLS equation, Gerdjikov–Ivanov-type DNLS equation, and Kundu-type DNLS equation and will be useful to further explore and apply the related nonlinear wave phenomena. [ABSTRACT FROM AUTHOR]

Chronic obstructive pulmonary disease (COPD) is a highly heterogeneous disease, and metabolomics plays a hub role in predictive, preventive, and personalized medicine (PPPM) related to COPD. This study thus aimed to reveal the role of induced sputum metabolomics in predicting COPD severity. In this pilot study, a total of 20 COPD patients were included. The induced sputum metabolites were assayed using a liquid chromatography-mass spectrometry (LC-MS/MS) system. Five oxidative stress products (myeloperoxidase (MPO), superoxide dismutase (SOD), glutathione (GSH), neutrophil elastase (NE), and 8-iso-PGF2α) in induced sputum were measured by ELISA, and the metabolomic profiles were distinguished by principal component analysis (PCA) and orthogonal projections to latent structures discriminant analysis (OPLS-DA). The Kyoto Encyclopedia of Genes and Genomes (KEGG) was used for pathway enrichment analysis, and a significant difference in induced sputum metabolomics was observed between moderate and severe COPD. The KEGG analysis revealed that the glycerophospholipid metabolism pathway was downregulated in severe COPD. Due to the critical role of glycerophospholipid metabolism in oxidative stress, significant negative correlations were discovered between glycerophospholipid metabolites and three oxidative stress products (SOD, MPO, and 8-iso-PGF2α). The diagnostic values of SOD, MPO, and 8-iso-PGF2α in induced sputum were found to exhibit high sensitivities and specificities in the prediction of COPD severity. Collectively, this study provides the first identification of the association between induced sputum metabolomic profiles and COPD severity, indicating the potential value of metabolomics in PPPM for COPD management. The study also reveals the correlation between glycerophospholipid metabolites and oxidative stress products and their value for predicting COPD severity. [ABSTRACT FROM AUTHOR]

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Exposure of plants and animals to ultraviolet-B radiation (UV-B; 280–315 nm) is modified by stratospheric ozone dynamics and climate change. Even though stabilisation and projected recovery of stratospheric ozone is expected to curtail future increases in UV-B radiation at the Earth's surface, on-going changes in climate are increasingly exposing plants and animals to novel combinations of UV-B radiation and other climate change factors (e.g., ultraviolet-A and visible radiation, water availability, temperature and elevated carbon dioxide). Climate change is also shifting vegetation cover, geographic ranges of species, and seasonal timing of development, which further modifies exposure to UV-B radiation. Since our last assessment, there has been increased understanding of the underlying mechanisms by which plants perceive UV-B radiation, eliciting changes in growth, development and tolerances of abiotic and biotic factors. However, major questions remain on how UV-B radiation is interacting with other climate change factors to modify the production and quality of crops, as well as important ecosystem processes such as plant and animal competition, pest–pathogen interactions, and the decomposition of dead plant matter (litter). In addition, stratospheric ozone depletion is directly contributing to climate change in the southern hemisphere, such that terrestrial ecosystems in this region are being exposed to altered patterns of precipitation, temperature and fire regimes as well as UV-B radiation. These ozone-driven changes in climate have been implicated in both increases and reductions in the growth, survival and reproduction of plants and animals in Antarctica, South America and New Zealand. In this assessment, we summarise advances in our knowledge of these and other linkages and effects, and identify uncertainties and knowledge gaps that limit our ability to fully evaluate the ecological consequences of these environmental changes on terrestrial ecosystems. [ABSTRACT FROM AUTHOR]

The focus of the present work is on the detailed characterization of the most relevant components of the intermolecular interaction, which determine anisotropic force fields driving the molecular dynamics under a variety of conditions. This target is here achieved by combining in a unifying picture the results of different type of experiments, probing complementary aspects of the intermolecular interactions involved. In particular, the analysis of high-resolution scattering data led to an accurate evaluation of the strength and anisotropy of non-covalent interaction components, due to the balance of size (or Pauli) repulsion with dispersion and induction attraction, to which electrostatic contributions must be added. Moreover, for the complete representation of the intermolecular interaction other components of covalent (chemical) nature, mostly affected by charge (electron) transfer effects, must be properly taken into account. Particular attention has been recently devoted to some experimental findings probing in detail the strength, range, anisotropy and role of the charge transfer effects. Obtained results have been important to develop suitable analytical representations for the potential energy surfaces (PESs), tested and improved by exploiting also the comparison with results of ab initio calculations, useful to provide an internally consistent description of the intermolecular interaction both in the most and less stable configurations of the interacting system. The complete and appropriate formulation of the PESs must be then considered crucial not only to describe the dynamics of elementary processes occurring in interstellar medium and in planetary atmospheres, but also to control equilibrium and non-equilibrium phenomena of applied interest, as those occurring in combustion, flames and plasmas. [ABSTRACT FROM AUTHOR]

The present paper describes a detailed study of a highly efficient protocol to multiply the number of haploids in sugar beet production and subsequent chromosome doubling. The protocol involves an experiment investigating factorial interactions between cold pretreatment, seven genotypes of sugar beet, and kinetin to improve haploid embryo induction. In addition, the effects of color of ovules and flower bud position on haploid embryo induction were investigated. After subjecting the data to analysis of variance or Student's t test ( P < .05), the effect sizes of the independent variables were also estimated. Cold pretreatment was effective in stimulating the ovules. The haploid embryo induction rate for 1-week cold pretreated ovules (9.01%) was higher than that of freshly cultured ones (6.15%). In comparison with hormone-free medium (5.16%), the gynogenesis rate for the media supplemented with 0.05 or 0.5 mg L kinetin increased to 7.58 and 10.05%, respectively. The genotype responses were significantly different. Interactions of kinetin × cold pretreatment, genotype × hormonal treatment, genotype × cold pretreatment, and the three-way interaction were statistically significant. Moreover, the main effects of flower bud position, ovule color, and comma-form ovule on gynogenic response were significant. After investigating the effect of 5 g L colchicine for 3, 5, or 7 min on one genotype's (SG2) specimens, all the haploid plantlets from the other genotypes were treated for 5 min as the best treatment. The paper discusses interactions of the factors, which may be interesting for others aiming to breed doubled haploid sugar beet or possibly other related plant species. [ABSTRACT FROM AUTHOR]

Although the use of minirhizotrons is increasing, many gaps in our scientific understanding of root systems remain. For example, relatively few studies have examined root responses to nutrient additions and mowing treatments in restored North American grasslands. In this project, we employed a combination of methods to evaluate the above- and belowground portions of restored grassland plots in western North Dakota (mixed grass prairie; 405 mm average annual precipitation). The plots were planted with various species combinations (1-20) and subjected to 5 years of nutrient additions (N, P, or control) and 3 years of mowing treatments (yearly fall mowing or no mowing). In general, we found the belowground variables (root length, surface area, number of tips, and number of branches) to be relatively unresponsive to the nutrient and mowing treatments. For instance, average root length was 309, 315, and 300 cm in the nitrogen, phosphorus, and control plots, respectively. In contrast, the aboveground variables exhibited pronounced responses to nitrogen applications (200 kg/ha year). Nitrogen applications increased aboveground biomass (660 vs. 265 g/m, respectively) and reduced average species richness compared to the control (3.25 species vs. 7.29 species, respectively). Our results indicated that the root systems in the plots that received nitrogen were able to support more aboveground biomass than were similarly sized root systems in plots that did not receive nitrogen. However, the observed increase in aboveground biomass came at a cost, as species richness was lower in the plots that received nitrogen. [ABSTRACT FROM AUTHOR]

Development of high-valued products through an integrated biorefinery approach is essential for the revival of the Canadian forest industry. Utilization of tree bark is one such example with considerable potential. The bark of trees contains a reservoir of phytochemicals that could be harnessed as value-added co-products. The objective of this study was to identify, characterize, and seek commercial potential of phytochemicals present in poplar bark. Industrially harvested poplar bark ( Populus tremuloides) was procured from Quebec. Water-soaked poplar bark was subjected to three steam-explosion treatments (treatments 1 to 3) using a steam-explosion reactor. During the experiment, extracts such as air purge, pre-steam purge, cooked purge, and pressed liquid were collected and subjected to compositional analysis. The results showed that the leftover bark residue even after the treatments was still fit for regular combustion for generating heat. Among the several identified phytochemicals (>100), furfural, 5-HMF, benzoic acid, salicylic acid, and catechol can be obtained as bulk chemicals, and sakuranin present at 15.9 % (extracted with acetone) as a high-valued and fine chemical. Considering the increasing demand for plant-based ingredients, there exists enormous potential to utilize these phytochemicals in agro-pharmaceutical industries. Further end-use studies, however, are required to ascertain the true economic potential of poplar bark phytochemicals. [ABSTRACT FROM AUTHOR]

Two, two-factor experiments manipulated species and functional form plant richness and the spatial scaling of either nitrogen (N) or phosphorous (P) in restored tallgrass prairie in North Dakota, USA. Nitrate (NO) leaching was measured in these plots and analyzed for its response to the treatment factors and measured plant community parameters. Nitrate extracted from anion exchange resin was regressed against the first principal component of species and functional form richness, the spatial scaling of N or P, the measured biomass of the functional forms used and the plot values for plant parameters based on weighted averages by species biomass. The treatments applied in the N and P experiments were 1, 2, 5, 10, or 20 plant species taxa, and the application of fertilizer in a random fractal pattern with either fine-scale or coarse-scale heterogeneity. Nitrate leaching decreased with plant diversity and increased by a factor of two going from fine-scale to coarse-scale N. It was also related to a number of plant functional parameters, and was positively correlated with the biomass of late successional C grasses ( Koeleria cristata (Lam.) Beauv., Poa pratensis L., Stipa comata Trin. & Rupr., and Stipa viridula Trin.), which are known from previous studies to have negative mycorrhizal responsiveness and are characterized by high root lateral spread per unit of root biomass. Our results show that while plant diversity has a highly significant influence on plant community uptake of NO, this effect is mediated by the scaling of soil N and the functional traits of the species comprising the plant assemblage. [ABSTRACT FROM AUTHOR]

There have been significant advances in our understanding of the effects of UV-B radiation on terrestrial ecosystems, especially in the description of mechanisms of plant response. A further area of highly interesting research emphasizes the importance of indirect UV radiation effects on plants, pathogens, herbivores, soil microbes and ecosystem processes below the surface. Although photosynthesis of higher plants and mosses is seldom affected by enhanced or reduced UV-B radiation in most field studies, effects on growth and morphology (form) of higher plants and mosses are often manifested. This can lead to small reductions in shoot production and changes in the competitive balance of different species. Fungi and bacteria are generally more sensitive to damage by UV-B radiation than are higher plants. However, the species differ in their UV-B radiation sensitivity to damage, some being affected while others may be very tolerant. This can lead to changes in species composition of microbial communities with subsequent influences on processes such as litter decomposition. Changes in plant chemical composition are commonly reported due to UV-B manipulations (either enhancement or attenuation of UV-B in sunlight) and may lead to substantial reductions in consumption of plant tissues by insects. Although sunlight does not penetrate significantly into soils, the biomass and morphology of plant root systems of plants can be modified to a much greater degree than plant shoots. Root mass can exhibit sizeable declines with more UV-B. Also, UV-B-induced changes in soil microbial communities and biomass, as well as altered populations of small invertebrates have been reported and these changes have important implications for mineral nutrient cycling in the soil. Many new developments in understanding the underlying mechanisms mediating plant response to UV-B radiation have emerged. This new information is helpful in understanding common responses of plants to UV-B radiation, such as diminished growth, acclimation responses of plants to UV-B radiation and interactions of plants with consumer organisms such as insects and plant pathogens. The response to UV-B radiation involves both the initial stimulus by solar radiation and transmission of signals within the plants. Resulting changes in gene expression induced by these signals may have elements in common with those elicited by other environmental factors, and generate overlapping functional (including acclimation) responses. Concurrent responses of terrestrial systems to the combination of enhanced UV-B radiation and other global change factors (increased temperature, CO2, available nitrogen and altered precipitation) are less well understood. Studies of individual plant responses to combinations of factors indicate that plant growth can be augmented by higher CO2 levels, yet many of the effects of UV-B radiation are usually not ameliorated by the elevated CO2. UV-B radiation often increases both plant frost tolerance and survival under extreme high temperature conditions. Conversely, extreme temperatures sometimes influence the UV-B radiation sensitivity of plants directly. Plants that endure water deficit stress effectively are also likely to be tolerant of high UV-B flux. Biologically available nitrogen is exceeding historical levels in many regions due to human activities. Studies show that plants well supplied with nitrogen are generally more sensitive to UV-B radiation. Technical issues concerning the use of biological spectral weighting functions (BSWFs) have been further elucidated. The BSWFs, which are multiplication factors assigned to different wavelengths giving an indication of their relative biological effectiveness, are critical to the proper conduct and interpretation of experiments in which organisms are exposed to UV radiation, both in the field and in controlled environment facilities. The characteristics of BSWFs vary considerably among different plant processes, such as growth, DNA damage, oxidative damage and induction of changes in secondary chemicals. Thus, use of a single BSWF for plant or ecosystem response is not appropriate. This brief review emphasizes progress since the previous report toward the understanding of solar ultraviolet radiation effects on terrestrial systems as it relates to ozone column reduction and the interaction of climate change factors. [ABSTRACT FROM AUTHOR]

Rationale: (1S,3aS)-8-(2,3,3,4,5,6-hexahydro-1H-phenalen-1-yl)-1-phenyl-1,3,8-triazaspiro[4.5]decan-4-one (Ro 64-6198), a non-peptidic agonist for the opioid receptor-like1 (ORL1) receptor, exhibits anxiolytic properties in stressful conditions. Objective: The present study was aimed at evaluating whether activation of ORL1 receptors by Ro 64-6198 may reverse the anorectic effect of restraint stress or intracerebroventricular (ICV) CRF injection. Methods: In body restraint experiments, 20-h food deprived rats were treated with intraperitoneal (IP) injection of Ro 64-6198 or vehicle. Ten minutes later, they were confined in cylindrical Plexiglas tubes for 60 min and then returned to their cage with food. In CRF experiments, 20-h food deprived rats were IP injected with Ro 64-6198 or vehicle. Ten minutes later, they received ICV CRF, 200 ng/rat or vehicle; food was offered after 20 min. Results: Intraperitoneal (IP) pretreatment with Ro 64-6198 reversed the hypophagic effect induced by both restraint or CRF; the effect was statistically significant at the three doses tested (0.3, 1.0 or 2.5 mg/kg). ICV administration of the selective ORL1 receptor antagonist [Nphe[sup 1] ]NC(1–13)NH[sub 2 ] (two injections of 33 or 66 µg/rat) abolished the effect of Ro 64-6198 on CRF-induced anorexia. In freely feeding rats, Ro 64-6198 significantly increased feeding at 2.5, but not at 0.3 or 1.0 mg/kg; in food deprived rats, Ro 64-6198 (0.3 or 1.0 mg/kg) did not modify food intake. Thus, reversal of stress- and CRF-induced anorexia by Ro 64-6198 can be evoked at doses lower than those that are hyperphagic. Ro 64-6198 (1 or 2.5 mg/kg) did not modify the anorectic effect of E. coli lipopolysaccharide, suggesting that its effect is selective for stress- or CRF-induced anorexia. Lastly, the benzodiazepine diazepam was unable to reduce the anorectic effect of CRF at the anxiolytic dose of 0.3 mg/kg, and partially reduced it at the hyperphagic dose of 1 mg/kg. Conclusions:... [ABSTRACT FROM AUTHOR]

In this article, we focus on the inverse scattering transform for the Gerdjikov–Ivanov equation with nonzero boundary at infinity. An appropriate two-sheeted Riemann surface is introduced to map the original spectral parameter k into a single-valued parameter z. Based on the Lax pair of the Gerdjikov–Ivanov equation, we derive its Jost solutions with nonzero boundary. Further asymptotic behaviors, analyticity and the symmetries of the Jost solutions and the spectral matrix are in detail derived. The formula of N-soliton solutions is obtained via transforming the problem of nonzero boundary into the corresponding matrix Riemann–Hilbert problem. As examples of N-soliton formula, for N = 1 and N = 2 , respectively, different kinds of soliton solutions and breather solutions are explicitly presented according to different distributions of the spectrum. The dynamical features of those solutions are characterized in the particular case with a quartet of discrete eigenvalues. It is shown that distribution of the spectrum and non-vanishing boundary also affect feature of soliton solutions. [ABSTRACT FROM AUTHOR]

Here, collective variables approach is applied to obtain optical solitons in the presence of perturbation terms. Gaussian solitons are selected to retain the pulse to establish soliton setting. The numerical simulations of soliton parameters are performed for specific values of the Gaussian pulse parameters. [ABSTRACT FROM AUTHOR]