Normal Population Research Articles

Electrochemical analysis on SnSeO3/ZnSeO3 nanocomposite

Nanocomposite SnSeO3/ZnSeO3 has been synthesized by hydrothermal method. X-ray powder diffraction confirms formation of SnSeO3/ZnSeO3 nanocomposite. It exhibits an interesting morphology of needle like nanorod structure. Thermal analysis reveals the thermal stability, decomposition behavior and critical temperatures where significant weight loss occurs. X-ray photoemission explains the role of the chemical state Sn, Zn, Se and O in SnSeO3/ZnSeO3. Electrochemical study has been made in both three electrode and two electrode system. In three electrode system, cyclic voltammetry exhibits a bell-shaped curve and the operational potential window is 0.8 V. The specific capacitance is 78.65 F/g for 5 mV scan rate. Chronopotentiometry shows quasi-triangular curves demonstrating the behavior of pseudo capacitors. Specific capacitances of 72.02 F/g was delivered at 1 A/g current density in 3M electrolyte of KOH. The plot of Nyquist for SnSeO3//ZnSeO3 confirms pseudo capacitor behavior. The series resistance Rs is low that is 0.78 Ω and charge transfer resistance is 0.42 Ω. Symmetric SnSeO3/ZnSeO3 supercapacitor device that is, two electrode system, is fabricated using 3M KOH electrolyte. Operational potential window is 1.5V. Cyclic voltammetry curves of the device show excellent capacitive behavior. The symmetric device produced specific capacitances of 39.37F/g, energy density 6.15 Wh kg-1 and power density 374.99 kW kg-1 at 1Ag-1 current density. The cell displayed 73.18% capacity retention, indicating excellent electrode stability for approximately 5000 cycles at a current density of 1 Ag-1 . Nyquist plot suggests that the system is stable and exhibits capacitive behavior.

Effects of a Manual Treatment on Lumbar Microcirculation and Tissue Stiffness Following Submaximal Eccentric Trunk Extensor Exercise: A Randomized Controlled Trial.

Recent studies have shown that the extramuscular connective tissue (ECT) is thickened and stiffened in delayed onset muscle soreness (DOMS). However, contrarily to the normal population, severe DOMS is rare in athletes or highly trained individuals. The present randomized, controlled trial therefore aimed to investigate pain as well as microcirculation and stiffness of the ECT and the erector spinae muscle following submaximal eccentric trunk extension exercise not causing DOMS. The effect of manual treatment by a therapist (myofascial release; MFR) on these parameters was to be studied. Trained healthy participants (n = 21; 31.3 ± 9.6 years; > 4 h exercise per week) performed submaximal eccentric exercise of the trunk extensors. One group was manually treated (n = 11), while the other group (n = 10) received placebo treatment with sham laser therapy. Stiffness of the ECT and the erector spinae muscle (shear wave elastography), microcirculation (white light and laser Doppler spectroscopy), palpation pain (100 mm visual analogue scale, VAS) and pressure pain threshold (indentometry, PPT) were assessed before (t0), 24 h (t24) and 48 h (t48) after conditions. Erector spinae muscle stiffness increased after eccentric exercise from t0 to t24 (0.875 m/s) and from t0 to t48 (0.869 m/s). After MFR, erector spinae muscle stiffness decreased in contrast to placebo treatment at t24 (-0.66 m/s), while ECT stiffness remained unchanged. Oxygen saturation increased (17-20.93%) and relative haemoglobin decreased (-9.1 - -12.76 AU) after eccentric exercise and MFR differed from placebo treatment at t48 (-3.71 AU). PPT differed after MFR from placebo treatment at t48 (20.69 N/mm), while VAS remained unchanged. Multiple linear regression showed that ECT stiffness and group membership predicted erector spinae muscle stiffness. MFR could have a positive effect on pain, microcirculation and muscle stiffness after submaximal eccentric exercise, suggesting better recovery, which needs to be confirmed by future work.

Analysis of clinical characteristics of patients with pulmonary hypertension in Chaya County, Chamdo, Tibet.

Pulmonary hypertension (PH) is a critical health issue marked by high blood pressure in the pulmonary arteries, with limited data on its clinical characteristics in the Tibetan population. The objective of this study was to examine the clinical characteristics of PH patients among Tibetan population residing in Chaya County, Changdu, Tibet. This was a retrospective cross-sectional study. A total of 94 PH patients diagnosed via echocardiography at the Internal Medicine Department of Chaya County People's Hospital in Changdu (Tibet, China) between March 2019 and October 2020 were included. Additionally, 52 non-PH inpatients were selected as the control group. Patient medical records were reviewed for demographic and clinical data, lab results, and echocardiographic findings. Student's t-test/chi-squared test between PH and control group, one-way analysis of variance (ANOVA) among control and PH subgroups, Pearson's and Spearman's correlation coefficient were used to analysis the results. Out of 1,689 inpatients in the Internal Medicine Department, 94 were identified as PH patients for analysis. The average hemoglobin level among PH patients (150.64±21.67 g/L) was similar to that observed in the normal population (146.65±17.51 g/L) at high altitude (P=0.28). Abnormal liver function indexes were observed, with 51.06% of PH patients exhibiting hyperuricemia (P<0.001 compared to control's 15.38%). The PH group demonstrated significantly elevated red blood cell distribution width (RDW)-standard deviation (50.59±6.49 vs. 43.67±3.40 fL, P<0.001) and RDW-coefficient of variation of (16.18%±3.04% vs. 13.52%±1.32%, P<0.001), along with a decreased platelet level compared to the control group [(202.55±73.67) vs. (256.63±72.85) ×109/L]. Furthermore, echocardiographic indicators related to right heart function showed correlations with red blood cell count, bilirubin, albumin, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol (multiple significant correlation coefficient r, magnitude from 0.22 to 0.54). Chronic pulmonary disease and left heart disease were identified as common etiologies of PH among Tibetan patients residing in high-altitude regions. The Tibetan population residing in high-altitude regions and diagnosed with PH displayed abnormal changes in numerous liver functional and metabolic indices, which were correlated with the morphological indices observed via cardiac ultrasound.

AGE STRUCTURE OF RHAPONTICUM SERRATULOIDES (GEORGI) BOBR. POPULATIONS. IN NORTHERN AND CENTRAL KAZAKHSTAN

The article presents the results of studying the ontogenetic structure of seven cenopopulations of Rhaponticum serratuloides in Karaganda and Akmola regions of Kazakhstan (Northern and Central Kazakhstan). The majority of surveyed cenopopulations belong to normal incomplete populations. Their ontogenetic structure has two main types of spectrum - centered two-vertex spectrum, where the maximum falls on virginal and middle-generative individuals, as well as left-sided spectrum with predominance of pre-generative individuals. The condition of cenopopulations was assessed using the "delta-omega" criterion of L. A. Zhivotovsky. According to this criterion, most of the cenopopulations are mature (CP 1-2, CP 4-5), only two (CP6 and CP7) are young. The presence of a significant number of young plants in CP6 indicates its high capacity for maintenance and self-restoration. In CP7, unfavorable conditions prevailed and potentially generative plants remained in virginile age state. CP3 occupies an intermediate position between mature and young populations. In all cenopopulations there was almost complete absence of senile and sub-senile individuals, and only in some of them - deposition of juvenile and immature individuals. Incompleteness of cenopopulations is associated with increasing anthropogenic load and narrow ecological amplitude of Rh. serratuloides.

Inference about a Common Mean Vector from Several Independent Multinormal Populations with Unequal and Unknown Dispersion Matrices

This paper addresses the problem of making inferences about a common mean vector from several independent multivariate normal populations with unknown and unequal dispersion matrices. We propose an unbiased estimator of the common mean vector, along with its asymptotic estimated variance, which can be used to test hypotheses and construct confidence ellipsoids, both of which are valid for large samples. Additionally, we discuss an approximate method based on generalized p-values. The paper also presents exact test procedures and methods for constructing exact confidence sets for the common mean vector, with a comparison of the local power of these exact tests. The performance of the proposed methods is demonstrated through a simulation study and an application to data from the Current Population Survey (CPS) Annual Social and Economic (ASEC) Supplement 2021 conducted by the U.S. Census Bureau for the Bureau of Labor Statistics.

A Generalization of Curve Mates: Normal Mate of a Curve

This a paper, a new curve pair is defined that generalizes some pairs of curves well known as Mannheim and Bertrand curve pairs. A normal curve pair is defined in such a way that a vector u obtained by overlapping the normal planes of the G and G* curves makes the same angle as the binormals of these curves. The relationship between torsions and curvatures of curve pairs was analyzed. Moreover, The unit quaternion q corresponding to the rotation matrix between the Frenet vectors of the curves was defined. In the conclusion, it is expressed express which famous pairs of curves will be obtained in which particular case.

Evaluation of the Risk of Malignant Arrhythmia Through Electrocardiography Parameters in Patients with Urinary Stone Disease

Introduction: With a lifetime frequency of 10-15% and a recurrence rate of up to 50% within 10 years, urinary stone disease is a major cause of comorbidity. Recently, it has become widely recognized that urinary system stone disease is not only limited to kidney stone development but is also linked to cardiovascular disease and various other illnesses. Malignant arrhythmias (sudden cardiac death and ventricular arrhythmias) are consequences of coronary artery disease. Despite numerous studies demonstrating that urinary system stone disease is a risk factor for coronary artery disease, no electrocardiographic parameters have been evaluated in this patient group This prospective observational study aims to assess ventricular repolarization parameters using electrocardiography, which are risk indicators for malignant arrhythmias in patients with urinary stones disease. Materials and Methods The study included patients diagnosed with urinary stone disease and healthy volunteers. All patients underwent 12-lead electrocardiography. The electrocardiographys were evaluated for QTc interval, QTc dispersion, T peak-end interval, and Tp-e/QTc, and compared with the control group. Results: When comparing the QTc interval, QTc dispersion, T peak-end interval, and Tp-e/QTc parameters between the patient and control groups, no statistically significant differences were found. Conclusion: Contrary to existing knowledge, this study found that malignant arrhythmias in patients with urinary stone disease were not significantly different from the normal population.

Primary Maxillary Hypoplasia in Complete Unilateral Cleft Lip and Palate: Analysis of Clinical Data and Associations

Objective: Investigate the volumetric differences between the cleft and noncleft hemi-maxillae in patients with complete unilateral CLP and compare them with the average population. It also aimed to correlate the hemi-maxilla volumetry with maxillary sinuses’ volumes, with the occlusal index in digitized models and tooth agenesis. Design: This is a retrospective cohort study. Setting: Cleft lip and palate center in quaternary-level institutions. Patients, Participants: This study included 23 patients with complete unilateral CLP who underwent cheiloplasty between 2008 and 2012 and a control group of 24 patients without craniofacial abnormalities. Interventions: None. Main Outcome Measure(S): The computed tomography scans of cleft patients were analyzed before and after alveolar bone grafting. Following 3-dimensional tomographic reconstruction, a volumetric index was calculated as the ratio of cleft and normal side volumes (CV/NV). Cuts and measurements were also conducted in the control group. Additionally, the volumetric index of the maxillary sinuses (MSCV/MSNV) was calculated, and occlusal index analyses were performed using digitized models. In addition, dental agenesis was observed. Results: The CV/NV relationship was significantly lower in the prealveolar and postalveolar bone grafting periods than in the normal population (P&lt;0.01), confirming primary maxillary hypoplasia in patients with complete unilateral CLP. The CV/NV decreased progressively with worsening occlusal index classifications (P=0.03). No associations were observed between MSV and any of the studied variables. Conclusion: The complex anatomy of patients with complete unilateral CLP impairs treatment outcomes, and maxillary hypoplasia must be considered an important predictive factor.

Three-dimensional continuum point cloud method for large deformation and its verification

This study presents a strong form based meshfree collocation method, which is named Continuum Point Cloud Method, to solve nonlinear field equations derived from classical mechanics for deformed bodies in three-dimensional Euclidean space. The method and its implementation are benchmarked against a nonlinear vector field using manufactured solutions. The analysis of mechanical fields firstly focuses on the study of St. Venant Kirchhoff and compressible neo-Hookean materials. Results for various initial boundary value problems are presented, including benchmark cases involving unidirectional tension and simple shear. Subsequently, the study concludes with an analysis of a displacement-controlled simulation of a compressible neo-Hookean material, specifically a bar that is pulled to 50% of its original length and rotated 90°. The pure tension case yields a 1.5% error in displacement between computed and expected values and a combined tension and torsion loading case provides further insight into material behavior under complex loading conditions. The resulting normal axial and transverse stress-strain curves are also presented. Finally, the consistency and robustness of the proposed nonlinear numerical schemes are successfully demonstrated through various numerical experiments.

Apodized chirped fiber Bragg grating for measuring the uniform and non-uniform characteristics of physical parameters

An apodized Chirped Fiber Bragg Grating (CFBG) is presented to compute and depict the sensing response for various uniform and non-uniform profiles of the temperature and the strain for different chirp parameters. The effectiveness of the CFBG can be reduced owing to the appearance of wide-scale side lobes as well as increasing group delay ripples (GDR). The introduction of apodization profile is highly impactful to enhance the sensing efficiency by minimizing the side lobes level along with the quantity of GDR. The sensing response of the apodized CFBG with different chirp parameters are evaluated for various ranges of uniform temperature (30 °C–80 °C) and strain (300 µ∊–550 µ∊). Furthermore, different non-uniform Gaussian profiles are also introduced to illustrate the overview for detecting and locating the spot size sources of measurands. This approach is highly desirable for estimating the structural integrity by ensuring the safety, efficiency, and reliability of the CFBG-based sensing outcomes.

The prince of insiders: a multiple pathway approach to understanding IP theft insider attacks

Purpose Intellectual property (IP) theft is an increasing threat that can lead to large financial losses and reputational harm. These attacks are typically noticed only after the IP is stolen, which is usually too late. This paper aims to investigate the psychological profile and the socio-technical events that statistically predict the likelihood of an IP threat. Design/methodology/approach This paper analyses 86 IP theft cases found in court documents. Two novel analyses are conducted. The research uses LLMs to analyse the personality of these insiders, which is followed by an investigation of the pathways to the attack using behaviour sequence analysis (BSA). Findings These IP theft insiders scored significantly higher on measures of Machiavellianism compared to the normal population. Socio-technical variables, including IP theft via photographs, travelling overseas, approaching multiple organisations and delivering presentations, were identified. Contrary to previous assumptions that there is a single pathway to an attack, the authors found that multiple, complex pathways lead to an attack (sometimes multiple attacks). This work, therefore, provides a new framework for considering critical pathways to insider attacks. Practical implications These findings reveal that IP theft insiders may come across as charming, star employees rather than the stereotype of disgruntled employees. Moreover, organisations’ policies may need to consider that IP theft occurs via non-linear and multiple pathways. This means that sequences of events need to be considered in detecting these attacks instead of anomalies outright. The authors also argue that there may be a case for “continuous evaluation” to detect insider activity. Originality/value This paper offers a new framework for understanding and studying insider threats. Instead of a single critical pathway, this work demonstrates the need to consider multiple interconnected pathways. It elucidates the importance of a multidisciplinary approach and provides opportunities to reconsider current practices in detection and prevention.

Metabolite and Transcriptome Profiling Analysis Provides New Insights into the Distinctive Effects of Exogenous Melatonin on Flavonoids Biosynthesis in Rosa rugosa.

Although the petals of Rosa rugosa are rich in flavonoids and their bioactivity has a significant impact on human health, the flavonoid content decreases during flower development. In this study, R. rugosa 'Feng hua' was used to investigate the effects of the melatonin foliar spray on enhancing the quality of rose by focusing on major flavonoids. The results showed that the contents of total flavonoids in rose petals at the full bloom stage induced by melatonin obeyed a bell-shaped curve, with a maximum at 0.3 mM, indicating the concentration-dependent up-regulation of flavonoid biosynthesis. In the treatment with 0.3 mM melatonin, metabolomic analyses showed that the concentrations of ten main flavonoids were identified to be increased by melatonin induction, with high levels and increases observed in three flavonols and two anthocyanins. KEGG enrichment of transcriptomic analysis revealed a remarkable enrichment of DEGs in flavonoid and flavonol biosynthesis, such as Rr4CL, RrF3H, and RrANS. Furthermore, functional validation using virus-induced gene silencing technology demonstrated that Rr4CL3 is the crucial gene regulating flavonoid biosynthesis in response to the stimulant of melatonin. This study provides insights into the exogenous melatonin regulation mechanism of biosynthesis of flavonoids, thereby offering potential industrial applications.

On the stability of fully nonlinear hydraulic-fall solutions to the forced water wave problem

Two-dimensional free-surface flow over localised topography is examined, with the emphasis on the stability of hydraulic-fall solutions. A Gaussian topography profile is assumed with a positive or negative amplitude modelling a bump or a dip, respectively. Steady hydraulic-fall solutions to the full incompressible, irrotational Euler equations are computed, and their linear and nonlinear stability is analysed by computing eigenspectra of the pertinent linearised operator and by solving an initial value problem. The computations are carried out numerically using a specially developed computational framework based on the finite-element method. The Hamiltonian structure of the problem is demonstrated, and stability is determined by computing eigenspectra of the pertinent linearised operator. It is found that a hydraulic-fall flow over a bump is spectrally stable. The corresponding flow over a dip is found to be linearly unstable. In the latter case, time-dependent simulations show that ultimately, the flow settles into a time-periodic motion that corresponds to an invariant solution in an appropriately defined phase space. Physically, the solution consists of a localised large-amplitude wave that pulsates above the dip while simultaneously emitting nonlinear cnoidal waves in the upstream direction and multi-harmonic linear waves in the downstream direction.

Mie scattering theory applied to light scattering of large nonhomogeneous colloidal spheres.

Colloidal suspensions made of smart core-shell structures are of current interest in many fields. Their properties come from the possibility of varying the core and shell materials for modifying the composite particles' chemical, biological, and optical properties. These particles are formed with a material with a constant refractive index core and a shell with a refractive index decaying until it matches the solvent refractive index. Poly(N-IsoPropyl AcrylaMide) (PNIPAM) is a typical example of materials forming shells. In this report, we present how to apply Mie scattering theory to predict and understand the static light scattering of large nonhomogeneous colloidal particles with spherical symmetry whose size is comparable with or larger than the light wavelength used for developing scattering experiments, where the Rayleigh-Gans-Debye approximation is not valid. Here, the refractive index decay was approximated by a Gaussian RI profile numerically evaluated through a multilayer sphere. We calculated the form factor functions of suspensions of PNIPAM microgels previously reported and core-shell suspensions made of polystyrene/PNIPAM at 20 and 40 °C synthesized by us. In all the cases, our method succeeded in providing the scattering intensity as a function of the angle. The software for using the numerical method is fairly straightforward and is accessible as an open-source code. The results can not only help predict and understand the photonic properties of microgels with large core-shell structures but also for any particle with a refractive index distribution with spherical symmetry, as in the case of microgels with super chaotropic agents, hollow microgels, or microparticles.

Impulsivity and Its Association with Depression and Anxiety in the Normal Egyptian Population Post COVID-19 Pandemic.

Background and Objectives: It is well known that depression, anxiety, and impulsiveness are interrelated; however, studies that have assessed their association with the coronavirus outbreak are scarce. Hence, our study aimed to evaluate the impulsivity incidence and its correlation with anxiety and depression following COVID-19 infection between November 2022 and June 2023. Materials and Methods: The 201 participants completed the Hamilton Depression Rating Scale (HDRS), Hamilton Anxiety Rating Scale (HAM-A), Sheehan Disability Scale (SDS), and short UPPS-P scales (urgency, premeditation, perseverance, sensation seeking, and positive urgency) to allow us to determine their anxiety and depression symptoms, functional impairment, and impulsivity, respectively. Results: Among our respondents, 22%, and 26.7% had moderate to severe anxiety and depression. The short UPPS-P scale significantly correlated with the HAM-A and HDRS scales. Participants with positive COVID-19 infection showed significantly higher functional impairment scores, especially in the work/study domain (mean (SD): 3.12 (2.2) vs. 2.43 (2.3); p = 0.037). COVID-19-related disruption significantly correlated with negative and positive urgency, HAM-A, HDRS, and the SDS total and subscales. Conclusions: Our findings showed a notable increase in anxiety, depression, and functional impairment among the population following COVID-19 infection. Our research highlights the correlation between impulsivity and the psychological distress experienced following the pandemic.

Compressive testing and modelling of additively manufactured stainless steel equal angle sections with stiffening wave patterns

Traditional structural steel manufacturing routes typically produce prismatic members comprising of flat plate elements. Under compressive actions, the capacity of these sections is often dominated by plate instability of the lowest buckling mode. The current study involves compressive testing of 6 different configurations of non-prismatic stub columns, comprising of pre-defined surface waves tested at 3 different slendernesses and 3 amplitudes including control prismatic sections. Absolute and normalised load-displacement curves are generated to compare against the control sections and assess the potential increase in strength and stiffness, and the samples’ weights are measured to evaluate the relationship between material use and strength when using this method of strengthening. Tensile coupon tests are also carried out on coupons printed from the same material to define material parameters, and an extensive parametric study is undertaken with numerical modelling software. The best case evaluated in this study indicated a strength gain of 89.9 % over a control section with an equal volume of used material. Eurocode-compatible buckling characterisation curves are then provided for two of the best performing sections. This study highlights the possibilities of this technology, paving the way towards unprecedented efficiency in future steel construction.

INFLUENCE OF HILLS AND VALLEYS ON FREE SURFACE SLIP AMPLIFICATION IN DYNAMIC RUPTURE ON A DIPPING FAULT

Dynamic rupture scenarios on various fault geometries are studied extensively in the literature for domains with the planar top surface. However, landscapes on the earth, particularly in tectonic regimes, can undulate upwards or downwards depending on faulting conditions. In this paper, we studied a dipping fault model with a dip fault angle of 60 degrees, inspired by the 2D version of dynamic rupture benchmark TPV10 from the Southern California Earthquake Center (SCEC). A topographic feature adjacent to the fault is introduced in the form of a hill or a valley. The shape of the undulation was varied from semi-circular form to Gaussian profile. This paper examines the impact of topographic features (valleys or hills) on slip amplitude on a fault. The distance at which the features exist also affects the amount of slip on fault, ruptured in that region. The results for a couple of different radii of semi-circular formation and equivalent standard deviation of Gaussian undulation are also summarized in this paper. The study depicts that the topography in the vicinity of the fault can affect the magnitude of slip propagation on fault surface.

Inference on the common mean direction of several Fisher-von Mises-Langevin populations with unknown concentration parameters

The problem of combining information from several samples for estimating or testing a common mean for normal populations has been extensively studied in the statistical literature. In this paper, we take up this problem in the context of the common mean direction of several Fisher-von Mises-Langevin (FvML) distributions. The concentration parameters are taken to be unknown and heterogeneous. A non-iterative combined estimator is proposed and is seen to have substantially better risk performance than individual sample mean directions and a grand mean direction in a simulation study. Further, a test based on this non-iterative estimator is proposed, and nonparametric bootstrap and permutation resampling methods are developed for its implementation. Two more alternative tests are proposed and their implementation is carried out using nonparametric bootstrap resampling. A detailed simulation study shows that these test procedures achieve the nominal size and have good power performance. An ‘R’ package is developed for the implementation of the tests. A real data set is considered for illustrating the procedures.

Age-dependent association between aneurysmal and isolated redundant inter-atrial septum with patent foramen ovale.

Interatrial septum (IAS) could be redundant by abnormal movement with or without aneurysmal bulging. We aimed to determine the prevalence of isolated redundant and aneurysmal IAS motion and their probable relationship with age and presence of patent foramen ovale (PFO) in a large-scale referral center. A total of 15,288 patients who underwent transthoracic echocardiography (TTE) at Tehran Heart Center were included From March 2019 to March 2021. Contrast echocardiography was conducted on patients with suspected PFO. Data were retrospectively analyzed from our previously established database. The prevalence of aneurysmal and redundant IAS and their relationship with age and PFO presence was evaluated. Aneurysmal and isolated redundant IAS were present in 4% and 12.4% of the participants, respectively. The aneurysmal group was older, more frequently female and had higher frequency of PFO. The frequency of PFO among patients with aneurysmal IAS was about 14.4% and 5.3% in isolated redundant IAS patients. In both groups, the prevalence of abnormal IAS motion increased across age groups from the youngest to the oldest, while the prevalence of PFO decreased. In conclusion, the frequency of PFO among patients with aneurysmal IAS was about 2.5 times more than that among patients with isolated redundant IAS and 24 times more than the normal population. The increasing trend observed across the aging group proposes a potential role for age in the pathophysiology of abnormal IAS. Furthermore, the decreasing prevalence of PFO among patients underlies its clinical significance as an important risk factor.

Habitat-driven otolith shape morphology in Oreochromis niloticus (pelagic) and Chrysichthys nigrodigitatus (benthic) from distinct zones of a tropical coastal lagoon system

This study explored the morpho-functional variations in the otoliths of Oreochromis niloticus (ON) and Chrysichthys nigrodigitatus (CN) across the Ikorodu (IKL) and Epe (EPL) regions in Nigeria's southern coastal lagoon system, with monthly sampling over twelve months. Digitized otoliths provided shape descriptors, and bathymetric analysis was conducted using the depth invariance index (DII). Remotely sensed reflectance (RSR) at 469 nm, 531 nm, and 555 nm assessed habitat productivity. Morpho-functional variations were evaluated using discriminant analysis (DA) and principal component analysis (PCA). Bathymetric analysis revealed that EPL has a deeper and more heterogeneous substratum than IKL. Additionally, Epe exhibited consistently higher RSR values than IKL. Sediment analysis showed higher clay and silt percentages in IKL and increased coarse sand in EPL, indicating distinct terrains. DA accuracy was high (ON: 92.0 %, CN: 90.8 % in cross-validation), highlighting variables such as area and circumference for ON and area, circularity, and compactness for CN. DA emphasized ellipticity, rectangularity, and roundness for ON, and form factor, compactness, circularity, and aspect ratio for CN. Higher reflectance values at EPL than at IKL indicate distinct ecological characteristics, with greater nutrient cycling and trophic productivity at EPL. Sediment analysis revealed distinct ecological heterogeneity and hydrological effects, with finer sediments in IKL indicating calmer conditions and EPL exhibiting higher energy conditions. Visualizing normal curve distributions for otolith shape descriptors in ON and CN populations revealed skewness patterns indicative of divergent adaptive features, possibly associated with habitat heterogeneity and productivity. The key otolith variables identified by DA and PCA suggest relative ecological opportunity and underscore the intricate relationships between otolith morphology and habitat variables (heterogeneity, productivity, sediment profile) in Nigeria's tropical southern lagoon system.