Matrix Maps Research Articles

"In Their Own Words": Families' Experiences With Tooth Autotransplantation for the Replacement of Maxillary Incisors in Children.

To examine families' experiences, including motivation and barriers to undergoing tooth autotransplantation (AT), and their perceptions of associated esthetic and functional outcomes. Semi-structured, in-depth-interviews (IDIs) were conducted in person with families who had children that underwent the AT procedure. Interviews were audio recorded and transcribed. Transcripts were coded and thematically analyzed both deductively and inductively. A facilitatorsand barriers matrix and journey maps were created to draw inferences on patterns arising from main themes. Twenty families selecting AT as a solution for a missing maxillary incisor were recruited and interviewed. Overall, all families interviewed had a positive experience with the AT procedure. Motivating factors for undergoing the AT procedure included wanting an earlier intervention for the missing incisor, wishing to mitigate negative psychosocial effects, and the anticipated positive outcomes that would last into adulthood. Barriers to uptake of the AT procedure included the lack of dental practitioner awareness of AT as a potential solution and a large number of appointments and travel. Families were also initially concerned over potential complications that could arise from their child undergoing this procedure. The cost of the procedure was both a barrier and a facilitator for treatment. The study results demonstrate that the overall AT is favorably considered by the families of growing children for the replacement of maxillary incisors and highlight factors that may act as motivators or barriers to its uptake.

On Singularity Properties of Word Maps and Applications to Probabilistic Waring Type Problems

We study singularity properties of word maps on semisimple Lie algebras, semisimple algebraic groups and matrix algebras and obtain various applications to random walks induced by word measures on compact p p -adic groups. Given a word w w in a free Lie algebra L r \mathcal {L}_{r} , it induces a word map φ w : g r → g \varphi _{w}:\mathfrak {g}^{r}\rightarrow \mathfrak {g} for every semisimple Lie algebra g \mathfrak {g} . Given two words w 1 ∈ L r 1 w_{1}\in \mathcal {L}_{r_{1}} and w 2 ∈ L r 2 w_{2}\in \mathcal {L}_{r_{2}} , we define and study the convolution of the corresponding word maps φ w 1 ∗ φ w 2 ≔ φ w 1 + φ w 2 : g r 1 + r 2 → g \varphi _{w_{1}}*\varphi _{w_{2}}≔\varphi _{w_{1}}+\varphi _{w_{2}}:\mathfrak {g}^{r_{1}+r_{2}}\rightarrow \mathfrak {g} . By introducing new degeneration techniques, we show that for any word w ∈ L r w\in \mathcal {L}_{r} of degree d d , and any simple Lie algebra g \mathfrak {g} with φ w ( g r ) ≠ 0 \varphi _{w}(\mathfrak {g}^{r})\neq 0 , one obtains a flat morphism with reduced fibers of rational singularities (abbreviated an (FRS) morphism) after taking O ( d 4 ) O(d^{4}) self-convolutions of φ w \varphi _{w} . Similar results are obtained for matrix word maps. We deduce that a group word map of length ℓ \ell becomes (FRS), locally around identity, after O ( ℓ 4 ) O(\ell ^{4}) self-convolutions, for every semisimple algebraic group G _ \underline {G} . We furthermore provide uniform lower bounds on the log canonical threshold of the fibers of Lie algebra, matrix and group word maps. For the commutator word w 0 = [ X , Y ] w_{0}=[X,Y] , we show that φ w 0 ∗ 4 \varphi _{w_{0}}^{*4} is (FRS) for any semisimple Lie algebra, improving a result of Aizenbud-Avni, and obtaining applications in representation growth of compact p p -adic and arithmetic groups. The singularity properties we consider, such as the (FRS) property, are intimately connected to the point count of fibers over finite rings of the form Z / p k Z \mathbb {Z}/p^{k}\mathbb {Z} . This allows us to relate them to properties of some natural families of random walks on finite and compact p p -adic groups. We explore these connections, characterizing some of the singularity properties discussed in probabilistic terms, and provide applications to p p -adic probabilistic Waring type problems.

Quantum Size-Driven Spectral Variations in Pillar[n]arene Systems: A Density Functional Theory and Wave Function Assessment.

This study explores the quantum size effects on the optical properties of pillar[n]arene (n = 5, 6, 7, 8) utilizing density functional theory (DFT) and wave function analysis. The mechanisms of electron transitions in one-photon absorption (OPA) and two-photon absorption (TPA) spectra are investigated, alongside the calculation of electron circular dichroism (ECD) for these systems. Transition Density Matrix (TDM) and electron-hole pair density maps are employed to study the electron excitation characteristics, unveiling a notable size dependency. Analysis of the transition electric dipole moment (TEDM) and the transition magnetic dipole moment (TMDM) reveals the electromagnetic interaction mechanism within pillar[n]arene. Raman spectra computations further elucidate vibrational modes, while interactions with external environments are studied using electrostatic potential (ESP) analysis, and electron delocalization is assessed under an external magnetic field, providing insights into the magnetically induced current phenomena within these supramolecular structures. The thermal stability of pillar[n]arene was investigated by ab initio molecular dynamics (AIMD).

Exploring the photovoltaic properties of naphthalene-1,5-diamine-based functionalized materials in aprotic polar medium: a combined experimental and DFT approach.

In this study, a series of naphthalene-1,5-diamine-based donor chromophores (ND1-ND9) with A-D-A architecture was synthesized through a condensation reaction between amines and substituted aldehydes. Various spectroscopic techniques i.e., FTIR, UV-Vis, 1HNMR and 13CNMR were performed for structural elucidation of naphthalene-1,5-diamine-based chromophores. Accompanying the synthesis, quantum chemical calculations were also accomplished at MPW1PW91/6-311G (d,p) functional of DFT/TD-DFT approaches to explore the photovoltaic properties of ND1-ND9 compounds. A comparative study between experimental and DFT results of vibrational and UV-Vis analyses showed a good harmony. All compounds showed band gaps in the range of 3.804-3.900 eV with absorption spectra in the UV region (397.169-408.822 nm). Frontier molecular orbital (FMO) findings revealed an efficient intramolecular charge transfer (ICT) from the central naphthalene-1,5-diamine-based donor core towards terminal acceptors. This significant charge transfer was also supported by the density of states (DOS) and transition density matrix (TDM) maps. All synthesized chromophores showed lower exciton binding energy values (E b = 0.670-0.785 eV), illustrating higher exciton dissociation rates with greater charge transfer in the studied chromophores. A reasonable harmony was obtained by comparative investigations of a standard hole transport material (HTM), Spiro-OMe TAD, with ND1-ND9 compounds, which illustrated that these synthesized chromophores might be considered as good HTMs. Therefore, all analyses indicated that the naphthalene-1,5-diamine-based chromophores might be utilized as efficient photovoltaic materials.

Effect of Benzothiadiazole-Based π-Spacers on Fine-Tuning of Optoelectronic Properties of Oligothiophene-Core Donor Materials for Efficient Organic Solar Cells: A DFT Study.

In this work, five novel A-π-D-π-A type molecules D1-D5 were designed by adding unusual benzothiadiazole derivatives as π-spacer blocks to the efficient reference molecule DRCN5T for application as donor materials in organic solar cells (OSCs). Based on a density functional theory approach, a comprehensive theoretical study was performed with different functionals (B3LYP, B3LYP-GD3, B3LYP-GD3BJ, CAM-B3LYP, M06, M062X, and wB97XD) and with different solvent types (PCM and SMD) at the extended basis set 6-311+g(d,p) to evaluate the structural, optoelectronic, and intramolecular charge transfer properties of these molecules. The B3LYP-GD3BJ hybrid functional was used to optimize the studied molecules in CHCl3 solution with the SMD model solvent as it provided the best results compared to experimental data. Transition density matrix maps were simulated to examine the hole-electron localization and the electronic excitation processes in the excited state, and photovoltaic parameters including open-circuit photovoltage and fill factor were investigated to predict the efficiency of these materials. All the designed materials showed promising optoelectronic and photovoltaic characteristics, and for most of them, a red shift. Out of the proposed molecules, [1,2,5]thiadiazolo[3,4-d]pyridazine was selected as a promising π-spacer block to evaluate its interaction with PC61BM in a composite to understand the charge transfer between the donor and acceptor subparts. Overall, this study showed that adding π-spacer building blocks to the molecular structure is undoubtedly a potential strategy to further enhance the performance of donor materials for OSC applications.

Cancer patients in the emergency department or intensive care unit: a 20-year bibliometric analysis of research progress and prospects

BackgroundAn increasing number of cancer patients may require emergency and intensive care at diagnosis and throughout their disease course. This study aimed to explore the progress, prospects, collaboration and network of research in the field of emergency and intensive care for cancer patients using bibliometric analysis.MethodsA search of the Web of Science (WOS) database was conducted to identify relevant articles in English published between 2000 and 2022. Bibliometric analysis platform and R-studio software were used for data analysis, which included cluster analysis, word cloud matrix, trend topics, and thematic maps based on author keywords and keywords plus.ResultsA total of 630 articles were included, with an average annual growth rate of 17.1%. The most active country in terms of productivity and collaboration was the United States. Trend topics evolved over time, with COVID-19 and epidemiology among the most recent hot topics. General topics such as palliative care, intensive care, emergency department, chemotherapy, management, and outcomes were identified, as well as specialized topics relating to the most common cancer types, and cancer- or treatment-related complications such as brain metastasis, hyperviscosity syndrome, spinal cord compression, pericardial tamponade, hemorrhage, respiratory failure, septic shock, venous thromboembolism, and malnutrition.ConclusionThere has been a increasing and evolving interest in emergency and intensive care for cancer patients over time.

Recognizing geochemical patterns related to mineralization using a self-organizing map

The recognition of geochemical patterns, including the spatial association of geochemical patterns, geochemical element associations, and geochemical anomalies related to mineralization, requires different methods to meet the corresponding requirements. In this study, a self-organizing map (SOM), an unsupervised learning technique, was employed to realize the whole processes of geochemical pattern recognition in southeastern Hubei Province, China. First, the clustering ability of SOM was adopted to reveal the spatial association of geochemical patterns; then, geochemical elemental associations were adopted according to the association between variables and clusters derived from the correlation analysis between the unified distance matrix (U-matrix) and SOM maps, and finally the quantification error (QE) of the SOM was adopted as an anomalous index to detect multivariate geochemical anomalies related to mineralization. The obtained results show that two of the clusters are spatially closely related to ore-forming geological bodies, that is Precambrian strata and Yanshanian intrusive rocks. The associations of Au–As–Ba–Cd–Sb–V and Au–Ag–Pb–Zn–Bi–Cu–Mo–Na2O–P–Sr–W are responsible for the characterization of the two clusters, and their combination was further used for multivariate geochemical anomaly detection. The extracted multivariate geochemical anomalies are closely spatially correlated with known gold polymetallic deposits. Both the receiver operating characteristic (ROC) and success-rate curves suggest a satisfactory anomaly detection results, which can provide guidance for further mineral exploration. The results of this study also suggest that SOM is an effective and interpretable tool for a better recognition of geochemical patterns related to mineralization.

Monitoring and forecasting of land use/land cover (LULC) in Al-Hassa Oasis, Saudi Arabia based on the integration of the Cellular Automata (CA) and the Cellular Automata-Markov Model (CA-Markov)

ABSTRACT This study sought to integrate the Cellular Automata-Markov Model (CA-Markov) and the Cellular Automata (CA) using sensing data for land cover maps for the years: 1988, 2000, 2013 and 2020 to monitor, detect, and predict the spatial and temporal of Land Use/Land Cover (LULC) change in Al-Hassa Oasis, Saudi Arabia. The maximum likelihood classifier (MLC) method was used as a supervised classification algorithm to super control classification coefficients. Training areas were extracted to classify green and water from Landsat images using The Natural Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI) indicators, respectively. The Markov form has been used Cellular Automata (CA)To create a Transition probability Matrix (TPM)), Transition Area Matrix (TAM) and Transition Suitability Maps (TSM), which is the main factor for obtaining to simulate the prediction of the future of land use/land cover in the years 2030 and 2050, while was used Cellular Automata-Markov Model (CA-Markov) To validate and Forecasting LULC. The results showed an expansion in urban areas by 63.5% equivalent to about 105.7 km2, and an increase in agricultural land by 6.6% equivalent to 10.7 km2 despite the loss of about 3.2% of the old agricultural land during the period 2000–2013 AD. Also, the area of marshes and water increased by about 41.7% equivalent to about 8.7 km, which led to the loss of 5.9% or the equivalent of about 139 km2 of arid lands during the past three decades. The projected LULC maps for 2030 and 2050 indicate that these patterns of arid lands that change into built-up areas and agricultural lands will continue over the next thirty years due to urban growth and the development of agricultural activities. The main strength of this study is the use of a relatively long period that allowed us to conduct a very good assessment of LULC in the study area, as well as to predict the different patterns for 2030 and 2050. Moreover, the results obtained in this study provide information to help decision makers to carry out effective practices for future planning and management of urban land growth and land use planning, especially in the Saudi Vision 2030.

High-performance non-fullerene acceptor-analogues designed from dithienothiophen [3,2-b]-pyrrolobenzothiadiazole (TPBT) donor materials.

Density functional theory (DFT) method was employed to investigate the electronic structure properties, excited state dynamics, charge transfer, and photovoltaic potential of benzo [1,2,5] thiadiazole fused to 3,7-dimethyl-3a,6,7,7b-tetrahydro-5H-thieno[2',3':4,5]thieno[3,2-b]pyrrole to form 3,9,12,13-tetramethyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2″,3″:4,5]pyrrolo[3.2-g]thieno[2',3':4,5]thieno[3,2-b]indole as the acceptor (A), bridge with thiophene as π-spacer to the donor moieties (D) which are 2,3-dihydrobenzo [b]thiophene-6-carboxylic acid (M4) and functionalized R, M1, M2, M3, and M5 to give a D-π-A-π-D. Here is the reverse combination for our molecules: the A-π-D-π-A type of chromophore configuration. It is also observed that tuning the dono-bridge configuration significantly increases the ease of charge transfer as the energy gap decreases in the order of 1.29 eV in M4 < 1.59 eV in M3 < 1.67 eV < 1.99 in M2 and 2.06 eV. The reorganization energy (RE) of M3 (0.0031) and M5 (0.0031) indicates an increase in the order of M3 > M5 > R > M2 > M4 > M1. The HOMO-LUMO indicates that the reactivity decreased, while the stability increased for the reference R at 0.990 eV, compared to the designed molecules M1-M5, with M1 being the least stable at 0.970 eV, while M4 exhibited the highest stability at 1.550 eV. The stability of the designed molecule decreased in the order of M4:1.550 > M3:1.257 > M5:1.197 > M2:1.010 > M1:0.970. Therefore, all results point to the electron-deficient core as an effective end-capped electron acceptor in M1-M5 compounds. As the ideal pair for successfully optimizing optoelectronic properties by reducing the HOMO-LUMO energy levels, reorganization energy, and binding energy and enhancing the absorption maximum and open-circuit voltage values in these designed molecules. DFT and TDDFT calculations were performed with Gaussian 16 program. The modelled compounds were optimized fully using the CAM-B3LYP, WB97XD, B3LYP, and MPW1PW91 functionals with the 6-31 G (d,p) basis set. The graphs for the density of states were plotted using the PyMOlyze software. Other molecular properties like the transition density matrix (TDM) and electron density difference maps (EDD) were rendered via the Multiwfn software.

Multi step structural health monitoring approaches in debonding assessment in a sandwich honeycomb composite structure using ultrasonic guided waves

This paper aims to investigate the use of ultrasonic guided wave (GW) propagation mechanism and the assessment of debonding in a sandwich composite structure (SCS) using a multi-step approach. Towards this, a series of GW propagation-based laboratory experiments and numerical simulations have been carried out on the SCS sample. The debonding regions of variable size and locations were assessed using a pre-defined network of piezoelectric lead zirconate transducers (PZT). Besides, several artificial masses were also placed in the SCS to validate the multi-step structural health monitoring (SHM) strategy. The SHM approach uses a proposed quick damage identification matrix maps and an improved elliptical wave processing (EWP) strategy of the registered GW signals to detect the locations of debonding and other damages in the SCS. The benefit of the proposed damage identification map is to locate the damaged area (sectors) quickly. This identification step is followed by applying the damage localization step using the improved EWP only on the previously identified damage sector region. The proposed EWP has shown the potential to effectively locate the hidden multiple debonding regions and damages in the SCS with a reduced number of calculations using a step-wise approach that uses only a selected number of grid points. The paper shows the effectiveness of the proposed approach based on data gathered from numerical simulations and experimental studies. Thus, using the above-mentioned SHM strategy debondings and damages present within and outside the sensor network are localized. The results were cross verified with nondestructive testing (NDT) methods such as infrared thermography and laser Doppler vibrometry.

ЗАСТОСУВАННЯ ГЕОІНФОРМАЦІЙНИХ СИСТЕМ ДЛЯ ВИРІШЕННЯ ЗАВДАНЬ НАВІГАЦІЙНОГО ЗАБЕЗПЕЧЕННЯ ВІЙСЬК

Rapid implementation of computer and information technologies in the activities of the troops (forces) is currently taking place, namely, significant successes in the use of geographic information systems (GIS) are noted. Modern GIS in the armed forces of other countries has also found wide application in the operational training of military C2 bodies, information support of combat actions, updating topographic maps, determining the location of the position of troops and individual servicemen, as well as in other areas of military activity. Therefore, it is necessary to analyze the most successful technologies and move towards their implementation. Currently, a large part of geographic information changes rapidly with time, which makes the use of traditional maps irrelevant. GIS is a software and technical complex that allows you to combine a model image of the territory with tabular information. The software and technical complex provides automated collection, processing, analysis, storage, display and distribution of spatially coordinated information. A computer system that makes it possible to edit, use, store, analyze and display graphic data in a cartographic form. GIS provide the most complete creation and timely restoration of the cartographic base. First of all, it concerns different types of cards. In addition, it is now possible to receive aerial, photographic and space images of local objects with minimal time delay, with the possibility of obtaining their specific characteristics. The speed of receiving information can only be guaranteed by a modern automated system with the possibility of documenting the provided information. The system allows you to create vector, raster and matrix maps, as well as quickly update various information about the area.

Convex invertible cones and Nevanlinna-Pick interpolation: The suboptimal case

Nevanlinna-Pick interpolation developed from a topic in classical complex analysis to a useful tool for solving various problems in control theory and electrical engineering. Over the years many extensions of the original problem were considered, including extensions to different function spaces, nonstationary problems, several variable settings and interpolation with matrix and operator points. Here we discuss a variation on Nevanlinna-Pick interpolation for positive real odd functions evaluated in real matrix points. This problem was studied by Cohen and Lewkowicz using convex invertible cones and the Lyapunov order, but was never fully resolved. In this paper we present a solution to this problem in a special case that we refer to as ‘suboptimal’ based on connections with the classical case. The solution requires a representation of linear matrix maps going back to R.D. Hill and an analysis of when positive linear matrix maps are completely positive, on which we reported in earlier work and which we will briefly review here.

Decoding Reed–Solomon Skew-Differential Codes

A large class of MDS linear codes is constructed. These codes are endowed with an efficient decoding algorithm. Both the definition of the codes and the design of their decoding algorithm only require from Linear Algebra methods, making them fully accessible for everyone. Thus, the first part of the paper develops a direct presentation of the codes by means of parity-check matrices, and the decoding algorithm rests upon matrix and linear maps manipulations. The somewhat more sophisticated mathematical context (non-commutative rings) needed for the proof of the correctness of the decoding algorithm is postponed to the second part. A final section locates the Reed-Solomon skew-differential codes introduced here within the general context of codes defined by means of skew polynomial rings.

Hill representations for [formula omitted]-linear matrix maps

In the paper (Hill, 1973) from 1973 R.D. Hill studied linear matrix maps L:ℂq×q→ℂn×n which map Hermitian matrices to Hermitian matrices, or equivalently, preserve adjoints, i.e., L(V∗)=L(V)∗, via representations of the form L(V)=∑k,l=1mHklAlVAk∗,V∈ℂq×q,for matrices A1,…,Am∈ℂn×q and continued his study of such representations in later work, sometimes with co-authors, to completely positive matrix maps and associated matrix reorderings. In this paper we expand the study of such representations, referred to as Hill representations here, in various directions. In particular, we describe which matrices A1,…,Am can appear in Hill representations (provided the number m is minimal) and determine the associated Hill matrix H=Hkl explicitly. Also, we describe how different Hill representations of L (again with m minimal) are related and investigate further the implication of ∗-linearity on the linear map L.

Linear matrix maps for which positivity and complete positivity coincide

By the Choi matrix criteria it is easy to determine if a specific linear matrix map is completely positive, but to establish whether a linear matrix map is positive is much less straightforward. In this paper we consider classes of linear matrix maps, determined by structural conditions on an associated matrix, for which positivity and complete positivity coincide. The basis of our proofs lies in a representation of ⁎-linear matrix maps going back to work of R.D. Hill which enables us to formulate a sufficient condition in terms of surjectivity of certain bilinear maps.

Matrix map between complex uncertain sequences

In this article we define matrix maps between complex uncertain sequences. We introduce the notion of bounded sequences of complex uncertain sequence for almost sure, mean, measure and distribution. We introduce the limitation method for different notion of boundedness of sequence of complex uncertain variables and establish relation between the different notions. The necessary condition for a matrix map to be a limitation method is established.

Deciphering Benzene–Heterocycle Stacking Interaction Impact on the Electronic Structures and Photophysical Properties of Tetraphenylethene-Cored Foldamers

Deciphering Benzene–Heterocycle Stacking Interaction Impact on the Electronic Structures and Photophysical Properties of Tetraphenylethene-Cored Foldamers

Performance comparison of coupling-evaluation methods in discriminating between pregnancy and labor EHG signals

BackgroundRecent years have seen an increased interest in electrohysterogram (EHG) signals as a means to evaluate the synchronization of uterine contractions. Several studies have pointed out that the quality of signal processing – and hence the interpretation of measurement results – is affected significantly by the choice of measurement technique and the presence of non-stationary frequency content in EHG signals. To our knowledge, the effect of time variance on the quality of EHG signal processing has never been fully investigated. How best to process EHG signals with the goal of distinguishing labor-induced contractions from their harmless, pre-labor cousins, remains an open question. MethodOur methodology is based on three pillars. The first consists of a new method for EHG preprocessing in which we apply a second-order Butterworth filter to retain only the EHG fast-wave, low-frequency band (FWL), then use a bivariate piecewise stationary pre-segmentation (bPSP) algorithm to segment the EHG signal into stationary parts. The second pillar addresses the estimation of connectivity and directionality using three methods: nonlinear correlation coefficient (h2), general synchronization (H), and Granger causality (GC). The third pillar is related to signal classification and discrimination between pregnancy and labor using receiver operating curves (ROC) and connectivity and direction maps. For this purpose, we analyze the impact of four factors on data processing efficiency: i) method of connectivity detection, ii) effect of piecewise stationary segmentation preprocessing, iii) retained frequency content and iv) electrode configuration used for EHG recording (bipolar vs. unipolar). ResultsOur results show that piecewise signal segmentation and filtering considerably improves classification performance and statistical significance for some connectivity methods, in particular the h2. To this end we propose a new approach (detailed below) for h2 called Filtered-Windowed (FW) h2 that better highlights the differences between pregnancy and labor in the connectivity matrix and directionality maps. ConclusionsThis is the first comparative study of the effects of multiple processing factors on connectivity measurement efficiency. Our results indicate that appropriate preprocessing can improve the differentiation of pregnancy and labor-induced contraction signals and may lead to innovative applications in the prevention of preterm labor.

Fluorescence Anisotropy Eems: Adding a New Dimension to the Study of Protein Local Environment

The characterization of complex mixtures such as cells, cell media, protein biotheraputics, API formulations, and polymeric solutions many times gives more questions than answers. Fluorescence Excitation Emission Matrices (EEMs) have been used for years now to study and even identify multiple components in such complex mixtures. With the development of 2-in-1 UV-visible absorbance and fluorescence spectrometers, the absorbance-transmittance EEM or A-TEEM enabled the acquisition of these matrices to be done more accurately and at higher fluorophore concentration ranges. We present another dimension to the study of complex mixtures with fluorescence spectroscopy using a combination of fluorescence anisotropy (FA) and A-TEEMs that can be used to study mixtures of multiple fluorophores from their local environment in terms of reorientational motion. For a solution of bovine serum albumin (BSA) protein, with multiple dye tracers, the local viscosity is measured in polar and non-polar local environments. Two dyes of varying polarity and solubility are used to track the local viscosity in both polar and non-polar regions of BSA protein in native and denatured forms as well as aggregated and non-aggregated states. Since anisotropy ratio is independent of dye concentration, the matrix maps show clearly any changes in local viscosity of both polar (water-soluble) and non-polar (hydrophobic) regions of the solution. Fluorescence Anisotropy A-TEEMs (FA-ATEEMs) quickly and easily enable the detection of proximate environment changes with respect to local viscosity and motion within protein solutions for multiple regions of the macromolecule.

Isotopic behavior and self-organizing maps for identifying groundwater salinization processes in Jerba Island, Tunisia

The purpose of this study is to assess the groundwater evolution in Jerba Island. This paper also focuses on the relationship between mineralization and anthropogenic activities and the identification of processes controlling groundwater geochemistry. An approach combining the use of water dissolved chemical species, isotopic fingerprint, and the self-organizing maps has been used to understand the behavior of a unconfined aquifer system and to determine the origin of its different contamination sources. In the present work, a geochemical characterization of the coastal aquifer from the unconfined Jerba aquifer, Southeast Tunisia, was carried out, using hydrogeochemical and isotopic (2H and 18O) data, correlation matrix, and self-organizing maps. For this aim, 79 wells were sampled and analyzed. Geochemical modeling and isotopic data demonstrated that seawater intrusion, exchange reactions occurring within the aquifer matrix, and anthropogenic activities were the major processes controlling the groundwater contamination in the island. The isotopic tracers indicate that the increasing salinity in the shallow coastal aquifer is caused by seawater intrusion. The methodology appears as a valid tool applicable in other coastal areas to determine the main factors governing the groundwater mineralization.