Complex-valued Research Articles

QSPR models for complexation performance of α-cyclodextrin and β-cyclodextrin complexes by norm indices

A generic method for predicting the complexation performance of cyclodextrins complexes is desirable. Two quantitative structure–property relationship models are established for the complexation performance of α- and β-cyclodextrins. The datasets consist of 229 α-cyclodextrin and 330 β-cyclodextrin complexes, including conventional organic molecules, ionic organic compounds, and drugs. Internal validation, indicated by the squared correlation coefficient (Q2) of 0.8949 and 0.8954 for α- and β-cyclodextrin models, demonstrates the stability and robustness of these models. For external validation, the squared correlation coefficients of test sets (R2test) are 0.9315 (α-cyclodextrin model) and 0.9171 (β-cyclodextrin model), confirming the predictive ability of both models. Furthermore, the complexation performances of two ionic liquids are measured using UV spectrometric titration for our models’ external prediction. The mean absolute error between measured and calculated values for β-cyclodextrin complexes is 0.20 M−1, indicating the satisfactory transferability of the model. For the α-cyclodextrin model, the mean absolute error of 1.25 M−1 is deemed acceptable. Both the model validations and experimental results underscore the robustness and predictive performance of these models. In conclusion, these developed models could effectively predict binding constants of several types of molecules with cyclodextrins, which can become valuable tools for cyclodextrin design.

Green Space and Apartment Prices: Exploring the Effects of the Green Space Ratio and Visual Greenery

Urban green spaces provide various social, economic, health, aesthetic, environmental, and ecological benefits. This study aimed to investigate the influence of green spaces on apartment prices, with a particular emphasis on visual greenery and the proportion of green spaces. Hedonic pricing models have often been used to assess the impact of green spaces on housing prices. Herein, 16 variables were considered as factors affecting housing prices and divided into housing, neighborhood, and green space characteristics. The findings indicate that the presence of green spaces enhanced the value of apartment complexes. Moreover, both visual greenery and the proportion of green spaces within apartment complexes influenced housing prices. Additional analysis demonstrated the impact of green space characteristics within Seoul apartment complexes on housing price changes from 2016 to 2022, finding that higher green space proportions and visual greenery led to approximately 20% higher price increases, and structural equation modeling revealed that the proportion of green spaces within apartment complexes, directly and indirectly, influenced housing prices through visual greenery. Overall, this study emphasized the importance of ensuring well-managed green spaces within and around apartment complexes.

Knot homologies and generalized quiver partition functions

We introduce generalized quiver partition functions of a knot K and conjecture a relation to generating functions of symmetrically colored HOMFLY-PT polynomials and corresponding HOMFLY-PT homology Poincaré polynomials. We interpret quiver nodes as certain basic holomorphic disks in the resolved conifold, with boundary on the knot conormal LK\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$L_K$$\\end{document}, a positive multiple of a unique closed geodesic, and with their (infinitesimal) boundary linking density measured by the adjacency matrix of the generalized quiver. The basic holomorphic disks that are quiver nodes appear in a certain U(1)-symmetric configuration. We propose an extension of the quiver partition function to arbitrary, not U(1)-symmetric, configurations as a function with values in chain complexes. The chain complex differential is trivial at the U(1)-symmetric configuration, under deformations the complex changes, but its homology remains invariant. We also study recursion relations for the partition functions connected to knot homologies. We show that, after a suitable change of variables, any (generalized) quiver partition function satisfies the recursion relation of a single toric brane in C3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\mathbb {C}}^3$$\\end{document}.

A novel therapeutic approach to prevent Helicobacter pylori induced gastric cancer using networking biology, molecular docking, and simulation approaches

Helicobacter pylori infects 50% of the world population and in 80% of cases, the infection progresses to the point where an ulcer develops leading to gastric cancer (GC). This study aimed to prevent GC by predicting Hub genes that are inducing GC. Furthermore, the study objective was to screen inhibitory molecules that block the function of predicted genes through several biophysical approaches. These proteins, such as Mucin 4 (MUC4) and Baculoviral IAP repeat containing 3 (BIRC3), had LogFC values of 2.28 and 3.39, respectively, and were found to be substantially expressed in those who had H. pylori infection. The MUC4 and BIRC3 inhibit apoptosis of infected cells and promote cancerous cell survival. The proteins were examined for their Physico-chemical characteristics, 3D structure and secondary structure analysis, solvent assessable surface area (SASA), active site identification, and network analysis. The MUC4 and BIRC3 expression was inhibited by docking eighty different compounds collected from the ZINC database. Fifty-seven compounds were successfully docked into the active site resulting in the lowest binding energy scores. The ZINC585267910 and ZINC585268691 compounds showed the lowest binding energy of −8.5 kcal/mol for MUC4 and −7.1 kcal/mol for BIRC3, respectively, and were considered best-docked solutions for molecular dynamics simulations. The mean root mean square deviation (RMSD) value for the ZINC585267910-MUC4 complex was 0.86 Å and the ZINC585268691-BIRC3 complex was 1.01 Å. The net MM/GBSA energy value of the ZINC585267910-MUC4 complex estimated was −46.84 kcal/mol and that of the ZINC585268691-BIRC3 complex was −44.84 kcal/mol. In a nutshell, the compounds might be investigated further as an inhibitor of the said proteins to stop the progress of GC induced by H. pylori. Communicated by Ramaswamy H. Sarma

Orchestration within plastics governance – From global to Arctic

The lack of coordinated global regulation of plastics with drivers such as increasing production and poor waste management continue to bring vast amounts of plastic pollution into our environments. Plastics are transboundary with often a complex value chain in production, use and waste handling and, until now, a fragmented regulatory response on how to solve this crisis. We utilize Abbott and Bernstein theory of orchestration to understand the actors at play attempting to regulate the life cycle of plastics within the ongoing treaty negotiations. When properly orchestrated, transnational governance can overcome the ineffective and fragmented mechanisms currently in use, thereby improving plastics regulatory performance. We utilize orchestration theory and participate observation at the ongoing treaty negotiations and explore to what degree the challenge of plastic pollution uses state orchestration to speed up the governance process.

New palladium complexes with N-heterocyclic carbene and morpholine ligands: Synthesis, characterization, crystal structure, molecular docking, and biological activities.

This work includes the synthesis of a new series of palladium-based complexes containing both morpholine and N-heterocyclic carbene (NHC) ligands. The new complexes were characterized using NMR (1 H and 13 C), FTIR spectroscopic, and elemental analysis techniques. The crystal structure of complex 1b was obtained by utilizing the single-crystal X-ray diffraction method. X-ray studies show that the coordination environment of palladium atom is completed by the carbene carbon atom of the NHC ligand, the nitrogen atom of the morpholine ring, and a pair of bromide ligand, resulting in the formation of slightly distorted square planar geometry. All complexes were determined for some metabolic enzyme activities. Results indicated that all the synthetic complexes exhibited powerful inhibitory actions against all aims as compared to the control molecules. Ki values of new morpholine-liganded complexes bearing 4-hydroxyphenylethyl group 1a-e for hCA I, hCA II, AChE, BChE, and α-glycosidase enzymes were obtained in the ranges 0.93-2.14, 1.01-2.03, 4.58-10.27, 7.02-13.75, and 73.86-102.65 µM, respectively. Designing of reported complexes is impacted by molecular docking study, and interaction with the current enzymes also proclaimed that compounds 1e (-12.25 kcal/mol for AChE and -11.63 kcal/mol for BChE), 1c (-10.77 kcal/mol and -9.26 kcal/mol for α-Gly and hCA II, respectively), and 1a (-8.31 kcal/mol for hCA I) are showing binding affinity and interaction from the synthesized five novel complexes.

Electromagnetic scattering of H‐polarised cylindrical wave by a double‐sided impedance circular strip

AbstractThe authors investigate electromagnetic scattering by a circular strip with impedance boundary conditions in detail. The excitation is obtained by the H‐polarised line source and the impedance boundary condition with different impedance values on each surface of the circular strip is imposed. Electromagnetic scattering from circular strips is formulated employing an integral equation approach including the orthogonal polynomials while expressing the current densities on inner and outer surfaces. To consider the edge condition, the current density on the scatterer is expressed in terms of Gegenbauer polynomials with the weighting function. Unlike the previous studies, the authors investigate the behaviour of the EM field regarding the location of the cylinder source, the size of the aperture and the different impedance values. The convergence of the proposed approach, which is one of the analytical–numerical methods, is investigated for different impedance values; considering the results, resonators with impedance surfaces of certain complex values and certain locations of the cylinder source perform better than the known PEC and PMC resonators for some specific resonance cases. An effective analytical–numerical approach is proposed for such geometry with the impedance boundary condition. An extensive analysis and comparison with other methods are provided. The limit cases of the impedance boundary condition (Dirichlet and Neumann boundary conditions) are validated.

Beam profile analysis in magnetoplasma medium

In the current study, electromagnetic fields produced by a point source in a magnetoplasma medium under the steady external magnetic field are derived by using Maxwell equations. To obtain the general Gaussian beams complex source point method is used. The radiated fields are Gaussian beams when the complex values are assigned to the source coordinates in the derived expressions. Due to the analytic continuation between real and imaginary source points being performed directly in the high frequencies no further calculations are required to convert ray solutions to beam solutions. Thus, the obtained beam solutions are valid outside the paraxial region therefore better representation of fields is obtained. The derived beam profiles are investigated for different set of parameters numerically.

QERaman: An open-source program for calculating resonance Raman spectra based on Quantum ESPRESSO

We present an open-source program QERaman that computes first-order resonance Raman spectroscopy of materials using the output data from Quantum ESPRESSO. Complex values of Raman tensors are calculated based on the quantum description of the Raman scattering from calculations of electron-photon and electron-phonon matrix elements, which are obtained by using the modified Quantum ESPRESSO. Our program also calculates the resonant Raman spectra as a function of incident laser energy for linearly- or circularly-polarized light. Hands-on tutorials for graphene and MoS2 are given to show how to run QERaman. All codes, examples, and scripts are available on the GitHub repository. Program summaryProgram Title:QERamanCPC Library link to program files:https://doi.org/10.17632/ddcrrrmxw9.1Developer's repository link:https://github.com/nguyen-group/QERamanLicensing provisions: GNU General Public Licence 3.0Programming language: FortranExternal routines:Quantum ESPRESSO v7.2Nature of problem: Resonance Raman spectra with first-principles calculations.Solution method: The Raman intensity formula is given by the quantum theory, in which the electron-photon and the electron-phonon matrix elements are obtained from the modified Quantum ESPRESSO package.

Independent prognostic value of high-risk ventricular premature complexes during exercise or recovery in asymptomatic patients: A meta-analysis of observational studies

IntroductionVentricular premature contractions (VPCs) are a common finding during cardiac stress tests. The independent prognostic value of these findings in patients in asymptomatic patients is unclear. MethodsWe conducted a systematic review and meta-analysis of observational studies exploring the independent prognostic value of VPCs to predict all-cause mortality. The secondary outcome was cardiovascular (CV) mortality. We excluded studies that did not report outcomes after adjusting for ≥1 confounder. Random effect meta-analyses were used to predict cumulative hazard ratios. We stratified results based on VPC during exercise or recovery. ResultsWe found 7 studies with 24,518 patients that met our inclusion criteria. Two studies reported all-cause mortality only, 1 study reported CV mortality only, rest 4 reported both. There was significant heterogeneity in the baseline population, definition of high-risk VPCs, and variables used in adjusted models. Using multivariable summary estimates from individual studies, only VPCs during exercise were associated with a higher risk of all-cause mortality (HR 1.27, 95 % CI 1.07, 1.48). Both VPCs during exercise and recovery were associated with a higher risk CV mortality (HR 1.69, 95 % CI 1.19, 2.20, I2 = 17.6 % and 1.62, 95 % CI 1.25, 2.00, p < 0.001 for both). ConclusionHigh-risk VPCs during exercise is associated with increased risk of all-cause and CV mortality, while those during recovery are associated with an increased risk of CV mortality only.

A comparative study of electronic structure, adsorption properties, and optical responses of furan and tetrahydrofuran adsorbed pristine, Al and Ga doped B12X12 (X=N and P) nanocages

Removing pollutants like furan (F) and tetrahydrofuran (THF) from the environment is challenging, and adsorption can efficiently remove pollutants. Fullerene like inorganic nanocages B12N12 and B12P12 are known for their efficient adsorption capability. To address these concerns, we report here the adsorption of the F and THF on the pristine and Al and Ga-doped B12N12 and B12P12 nanocages and consequently the change in the electronic structure, property and optical responses. Doping Al and Ga at the nanocage diminishes the HOMO-LUMO energy gap by 2.9 to 0.4 eV compared to the pristine cage, making the doped cage surface more reactive. The doped surface of nanocage adsorbs F (F@AlB11N12 (-130.1 kJ/mole) and THF (THF@AlB11N12 (-202.3 kJ/mole) more effectively compared to pristine ones (F@B12N12 -28.7 kJ/mole, THF@B12N12 (-98.3 kJ/mole) at ωB97XD/6–31+G(d,p) level. For a given cage, THF is more strongly adsorbed (THF@B12N12 (-98.3 kJ/mole)) on the cage surface than F (F@B12N12 -28.7 kJ/mole). Interestingly, Al-doped cages exhibit the highest adsorption energy value ranging from -68.5 kJ/mole to -202.3 kJ/mole. Natural bonding orbital analysis, global reactivity descriptor, molecular electrostatic potential, frontier molecular orbital, etc. have been employed to comprehend the distinctive patterns of adsorption. The optical response properties of the studied complexes show that the complexes of B12P12 nanocages exhibit higher polarizability and second hyperpolarizability value (1.51 × 105 to 1.62 × 105 au) compared to its analogous B12N12 complex (3.62 × 104 to 4.15 × 104 au) at ωB97XD/6–311+G(d,p) level. Our theoretical results further demonstrate the capability of AlB11N12 and AlB11P12 as promising adsorbents of the toxic organic pollutants F and THF, and the computed higher second hyperpolarizability value of the B12P12 complexes indicates these nanomaterials could be used as potential optoelectronic materials.

Modulation of optical oxygen sensitivity of H2(TPP) by using Eu3+, Gd3+ and Yb3+ ions doped silicate-based bioactive glass powders immersed in simulated body fluid

Improving the performance of optical oxygen sensors can be accomplished by adding additives to the composition comprising an oxygen-sensitive probe encapsulated in a polymeric matrix. In this study, to advance the oxygen sensing ability, free meso-tetraphenyl porphyrin (H2(TPP)) was chosen as a luminophore. The sol-gel based 13–93 bioactive glass powders (BG) co-doped with ytterbium (Yb3+), gadolinium (Gd3+), and europium (Eu3+) and immersed in simulated body fluids (SBF) were also used as additives. After being immersed in SBF, bioactive glasses containing Eu3+, Gd3+, and Yb3+ were found to be able to convert hydroxyapatite corresponding to in vitro bioactivity tests. The optimum additive concentration for all glass samples is 3 wt%, based on photoluminescence-based properties. The luminescence dye was incorporated into poly(trimethylsilylpropyne) [poly(TMSP)] matrices in the form of a thin film along with bioactive glass additives to improve oxygen sensitivity. Emission-based intensity values of all porphyrin complexes have been followed as a signal drop during oxygen sensing measurements. The H2(TPP) along with the additive of BG:Eu3+ showed a 6.88 fold of I0/I ratio compared to the undoped and Gd3+ and Yb3+-doped BG forms in terms of the relative signal change. Large Stoke's shift (Ksv) values, high luminescence abilities, and linear spectral response make them promising candidates as oxygen sensing agents. It was concluded that prepared bioactive glass powders are suitable to use as additive materials for improving the oxygen sensitivity of meso-tetraphenyl porphyrin dye.

Ascorbic and salicylic acids modulate the binding interactions of an emergency contraceptive pill levonorgestrel to a model transport protein: Insights from spectroscopy and molecular docking analysis

Serum proteins generally help to transport and distribute drug molecules within the body. In this study, the binding characteristics of bovine serum albumin (BSA) with levonorgestrel (LVG), an emergency contraceptive pill, and the influences of ascorbic acid (ASC) and salicylic acid (SAL) on the binding behaviour and protein structure were elucidated using multi-spectroscopic techniques and molecular docking. The results showed that levonorgestrel decreased BSA intrinsic fluorescence via static quenching mechanism. Binding constant (Ka) values for BSA-LVG complexes were 103 to 104 M-1, indicating their high stabilities. Site probing/docking analysis indicated LVG bound between BSA subdomains IIA and IIIA. UV–visible absorption, Fourier Transform-Infrared and 3D fluorescence spectroscopies affirmed LVG-induced changes in BSA structure, especially in α-helix and β-sheet contents. ASC and SAL influenced BSA conformation for LVG binding and reduced the Ka values by 3.37 and 5.43-folds, respectively. LVG altered the microenvironments of tyrosine residues, interacted with Arg-217, Lys-221, Val-292, Glu-443 etc. within the binding domains. The process was spontaneous (ΔG<0), entropy driven (TΔS>ΔH) and involved van der Waals forces and hydrogen bonding. The findings of the study offered details on the binding interaction between BSA and LVG, and also indicated that prior intake of ASC or SAL could suppress the binding affinity of BSA for levonorgestrel.

Evaluation of Fire Protection systems in Residential High-rise Buildings for Evacuation Optimisation- A Case of Bengaluru

Significance of the research- Among different types of occupancies, a Residential high-rise building presents a more significant challenge to fire protection due to its functionality, complexity, and economic value. Objective of the study- The key objective of the present paper was to examine the situation of physical (as opposed to non-physical) fire protection systems in randomly selected Residential high-rise buildings in Bengaluru for Evacuation optimization. Methodology- Methods used include Physical observation, document review, and interviews. A multi-attribute evaluation model/approach was applied to establish the sufficiency or suitability of fire protection systems in light of NBC-2016 [1] and Bangalore Byelaws-2016. The study reveals that fire-fighting/evacuation lifts and other fire protection systems are primarily present in the buildings. Nevertheless, due to inadequate maintenance or unsuitable elements, their safety performance is compromised. Research findings- The analysis revealed that fire hoses and hydrants demonstrated the highest level of adequacy and suitability in terms of their number, locations, and maintenance across the buildings. Conversely, only 50% of the buildings had a sprinkler system that was sufficiently installed, indicating a need for improved coverage and maintenance, possibly due to cost considerations. The performance of other systems was as follows: fire driveways (83%), fire escape staircases (83%), fire detection and alarm (40%), corridors and passageways (67%), assembly areas (83%), hose reels and hydrants (100%), fire brigade access and facilities (67%), safety signs and notices (17%), portable fire extinguishers (50%), and fire audits (17%). Based on these findings, it is recommended to prioritize increased efforts in inspecting and maintaining fire protection systems throughout the lifespan of the project to address the identified shortcomings. Additionally, the design of residential high-rise buildings should incorporate provisions for fire-fighting evacuation lifts and facilities catering to the needs of disabled individuals.

Nonlinear optical properties of novel crystalline complexes of cobalt (II) and nickel (II) with 4-bromo-3-methyl-1H-pyrazole: combined experimental and computational study

Two new isostructural cobalt [Co(II)(C4H5BrN2)4(Cl)2], I and nickel [Ni(II)(C4H5BrN2)4(Cl)2], II complexes were synthesized for linear and nonlinear optical (NLO) responses using the finite field method. The synthesized complexes were characterized using elemental analysis, infrared and H-NMR spectroscopy, TG/DSC analysis, and X-ray crystallography. The crystal analysis indicates that both complexes I and II are mononuclear, and crystallize in the monoclinic space group P21/c. The metal ion in each complex is six coordinated with four nitrogen atoms (from 4-bromo-3-methyl-1H-pyrazole ligand) and two chloride ligands adopting octahedral coordination geometry. Furthermore, the computational predictions for molecular geometries and average third-order nonlinear polarizabilities of I and II are made in current study. The average theoretically predicted third-order nonlinear polarizabilities 〈γ〉 of I and II are 95.50 × 10−36 and 91.25 × 10−36 esu, respectively. The 〈γ〉 amplitudes values of complexes I and II are ∼5.26 and ∼5.0 times greater than the prototype NLO molecule of para-nitroaniline (p-NA) at same level of theory, which indicates their decent potential as efficient NLO materials.

Some Practical Applications of Discretely Tunable Couplers’ Matrix Model

The findings of a research of the practical application of a previously developed model of a decametric waves discrete coupler are presented. Due to the high accuracy achieved in describing the transforming properties of Coupler in the operating frequency range, together with the apparatus of the theory of complex variables, in particular with the method of conformal maps of fractional linear functions, it was possible to solve a number of applied problems. A method for calculating the area of consistent loads of discretely tunable power circuits of arbitrary structure has been developed. For completeness of the result, the case of matching a generator with a complex value of internal resistance with a given quality (with an acceptable value of the traveling wave coefficient) has been considered. The proposed approach to matching assumes that for any possible antenna load there must be appropriate combinations of discretely tunable elements of the Coupler power circuit that ensure matching with a given quality. The design ratio for images of arbitrary circles and straight lines conformally mapped by a matching quadrilateral to a given complex domain (i.e., expressions for calculating the coordinates of the circle center and its radius, as well as coefficients of the equation of straight lines) has been obtained. Studies of the matching properties of various circuits implemented on discrete elements have been carried out. The results of this study are important when choosing the structural design of the Coupler power circuit. Calculation formulas are obtained that allow us to estimate the relative losses of active power in the Coupler power circuit. This contributes to the reasonable choice of the best configuration option from several, similar in quality matching, thereby avoiding complicated temperature settings of the circuit elements. An exhaustive search method of tuning the discrete contour of the Coupler has been proposed, which is extremely simple and does not require heavy calculations with matrices and complex numbers.

Holomorphic functions on the disk with infinitely many zeros

Suppose that \phi(z)=\sum_{n=1}^\infty d_nz^n is a series with radius of convergence greater than 1 and suppose that d_n are real numbers such that \phi(1)\neq0 . We prove that for any integer a greater than 1 , the complex variable function f(z)=\sum_{n=0}^{\infty}\phi(z^{a^n})=\phi(z)+\phi(z^a)+\phi(z^{a^2})+\phi(z^{a^3})+\cdots has infinitely many zeros on the unit disk. It even takes every complex value in every disk centered in any point of the boundary.

New Coumarin−Thiosemicarbazone Based Zn(II), Ni(II) and Co(II) Metal Complexes: Investigation of Cholinesterase, α‐Amylase, and α‐Glucosidase Enzyme Activities, and Molecular Docking Studies

AbstractNew coumarin−thiosemicarbazone compounds and their zinc(II), nickel(II), and copper(II) metal complexes were synthesized and characterized. The inhibitory activities of these new coumarin−thiosemicarbazone‐based metal complexes against butyrylcholinesterase (BChE), acetylcholinesterase (AChE), α‐amylase, and α‐glucosidase were determined. The results showed that all the synthetic compounds exhibited potent inhibitory activities against all targets, as compared to the standard inhibitors, as revealed by the half‐maximal inhibitory concentration (IC50) and the inhibitory constant (Ki) values. The Ki values of the new complexes for BChE, AChE, and α‐glucosidase enzymes were obtained in the ranges of 115.84–276.07, 31.68–117.08, and 22.56–47.82 μM, respectively. Moreover, molecular docking studies provided support for the conclusion that coumarin−thiosemicarbazone zinc(II) (−102.34; −10.41 kcal/mol) and coumarin−thiosemicarbazone cobalt(II) complexes (−25.46; −9.49 kcal/mol) act as dual inhibitors for both AChE and α‐amylase species. Furthermore, coumarin−thiosemicarbazone cobalt(II) (−39.46 kcal/mol) and coumarin−thiosemicarbazone nickel(II) complexes (−39.41 kcal/mol) demonstrated potential as inhibitors of α‐glucosidase. Of all the compounds studied, bis‐3‐benzyl‐7,8‐dimethoxycoumarin−thiosemicarbazonato zinc(II) is the most potent drug against AChE.

Physics-informed neural network for predicting unmeasured ocean acoustic pressure field

This study employs a physics-informed neural network in an ocean waveguide to predict the unmeasured acoustic pressure field, leveraging partially measured data. The method addresses a scenario where an acoustic source transmits signals across different ranges and is measured by multiple receivers. The acoustic pressure field in ocean waveguides exhibits rapid spatial variations over kilometer-range scales. The fully connected neural networks encounter challenges when approximating high-frequency functions, known as spectral bias. To mitigate this problem, the measured pressure field is transformed into a low-frequency function for training the neural network. We propose two methods sharing the same neural network architecture but utilizing different information. The first method uses a complex value of the pressure field (i.e., both magnitude and phase), while the second method uses only magnitude. We validate the proposed methods using simulations and experimental data from the SWellEx-96 environment. Results demonstrate that the first method exhibits superior performance with sparse data, while the second method works better in real-world scenarios.

A qualitative analysis of health information-sharing networks in the Indonesian poultry sector.

Animal production systems are developing into increasingly complex value chains involving a large diversity of actors with multiple and dynamic linkages, concurrently creating many opportunities for disease spread. Access to timely and good-quality animal health information is vital for designing effective disease management strategies. However, several factors may hamper information flows along those chains. Understanding the structure and dynamics of information networks is essential to develop effective and acceptable health information systems. We applied a qualitative network approach to understand how information about poultry health is generated, disseminated and used for decision-making along the poultry value chain in Indonesia. Maps of the value chain and information networks were generated based on data from key informant interviews to illustrate the linkages and information-sharing patterns between stakeholders. Four types of farm business models were identified: company-owned, contract, partnership and independent. Although companies and most independent farmers collected health and production data routinely, their systems were strongly siloed and still relied on a mix of digital and paper-based methods, which impaired their analytical capacity. Technical service providers from the upstream sector and industry associations were identified as key intermediaries in the information-sharing network with the ability to create informal bridges between separate business networks and public actors. These actors can play a strategic role in the development of integrated information systems to improve stakeholders' capacity to monitor, anticipate and manage disease threats at all levels of the value chain. This study contributes to fill an important knowledge gap regarding the layer sector and may help decision-makers to design effective policies and interventions tailored to the type of business model.