Small Lens Research Articles

Deletion upstream of MAB21L2 highlights the importance of evolutionarily conserved non-coding sequences for eye development

Anophthalmia, microphthalmia and coloboma (AMC) comprise a spectrum of developmental eye disorders, accounting for approximately 20% of childhood visual impairment. While non-coding regulatory sequences are increasingly recognised as contributing to disease burden, characterising their impact on gene function and phenotype remains challenging. Furthermore, little is known of the nature and extent of their contribution to AMC phenotypes. We report two families with variants in or near MAB21L2, a gene where genetic variants are known to cause AMC in humans and animal models. The first proband, presenting with microphthalmia and coloboma, has a likely pathogenic missense variant (c.338 G > C; p.[Trp113Ser]), segregating within the family. The second individual, presenting with microphthalmia, carries an ~ 113.5 kb homozygous deletion 19.38 kb upstream of MAB21L2. Modelling of the deletion results in transient small lens and coloboma as well as midbrain anomalies in zebrafish, and microphthalmia and coloboma in Xenopus tropicalis. Using conservation analysis, we identify 15 non-coding conserved elements (CEs) within the deleted region, while ChIP-seq data from mouse embryonic stem cells demonstrates that two of these (CE13 and 14) bind Otx2, a protein with an established role in eye development. Targeted disruption of CE14 in Xenopus tropicalis recapitulates an ocular coloboma phenotype, supporting its role in eye development. Together, our data provides insights into regulatory mechanisms underlying eye development and highlights the importance of non-coding sequences as a source of genetic diagnoses in AMC.

A small lens on timescales and multimodality in classroom language learning emotions

AbstractEmpirical work exploring additional language (L+) learning emotions has both proliferated and expanded its focus over the past 15 years. The current article explores one possibility for responding to the challenge of capturing and describing emotions in order to furnish a more contextualized, multidimensional picture of emotions in L+ learning: the small‐lens approach. From the perspective of the author as a practitioner–researcher, this article draws on data from an L+ discussion activity. Via the activity, the practitioner–researcher identified an emotional outcome of interest and examined the historical buildup to this phenomenon. A narrative of the research process applied aims to illustrate the ways in which multimodal analysis and interrogation of psychological timescales might illuminate intersections between the social and individual. Rather than delineating a complete description of the research, the article strives to intimate possibilities and stimulate more nuanced, situated, and dynamic empirical work into the emergence of emotions in instructed L+ learning. While not the primary focus, some of the teleological (functional) aspects of emotions and emotional expression are also unearthed.

Analysis of corneal surface shape following overnight orthokeratology with different optical zone diameters.

This study analyzed the corneal surface shape following overnight orthokeratology with different optical zone diameters. A total of 82 eyes belonging to 41 myopic children who completed 1 month of the orthokeratology (ortho-k) lens wear at the Eye Hospital of Wenzhou Medical University from January 2022 to January 2023 were retrospectively analyzed. According to the size of the base curve (BC) of ortho-k lens, patients were divided into BC 5.0 and BC 6.0 groups. The changes in decentration distance and corneal refraction of the two groups after the ortho-k lens wear were analyzed. Independent sample t-tests were used to compare these two outcome measures between the two groups. The decentration distance of BC 5.0 group (0.37 ± 0.19 mm) was significantly lower than that of BC 6.0 group (0.49 ± 0.25 mm, t = -2.330, p = 0.022). In the BC 5.0 group, the direction of decentration was superonasal in 3 cases, inferonasal in 2 cases, inferotemporal in 21 cases, and superotemporal in 6 cases. In the BC 6.0 group, the direction of decentration was superonasal in 2 cases, inferonasal in 2 cases, inferotemporal in 27 cases, and superotemporal in 19 cases. The optical zone area (8.19 ± 2.96 mm2) and reverse curve zone area (30.05 ± 6.74 mm2) in the BC 5.0 group were significantly lower than in the BC 6.0 group (10.42 ± 2.03 mm2, t = -4.043, p < 0.001; 38.21 ± 4.77 mm2, t = -6.422, p < 0.001). The change in the rate of refraction in the horizontal direction in BC 5.0 group were significant higher than in BC 6.0 group. Base curve 5.0 mm ortho-k lens is better positioned than BC 6.0 mm lens. A small BC ortho-k forms a smaller optical zone and reverse curve area, which might get a greater aiameter of alignment curve to facilitate positioning better than the traditional BC lens. In addition, a small BC lens increases positive refraction in the peripheral area, resulting in a greater negative pressure than the traditional BC lens.

Comparative study of visual and refractive outcomes of laser assisted in situ Keratomileusis versus small incision lenticule extraction versus implantable collamer lens for moderate to high myopia correction

Background Myopia represents a condition of refraction, in which parallel light rays converge in front of the resting eye retina. Aim To compare the laser assisted in situ keratomileusis (LASIK) visual and refractive outcomes versus small incision lenticule extraction (SMILE) versus implantable collamer lens (ICL) while correcting cases having moderate to high myopia. Patients and methods Our research involved 60 eyes having moderate to severe myopia ranging from –3 to –10 dioptres. They divided into three equal groups, group A: through LASIK, group B: through SMILE, and group C: received an ICL. Preoperative uncorrected visual acuity, Corrected distance visual acuity, and Manifest and cycloplgic refraction assessments were accomplished. Results Postoperative uncorrected visual acuity exhibited no significant variation among groups A and B, yet a significant variation was documented among groups A and C as well as among groups B and C P less than 0.001. The postoperative spherical error showed no significant variation among groups A and B nor among groups B and C yet exhibited significant variation among groups A and C P=0.002. Postoperative astigmatism was no significant variation among groups A as well as B, yet a significant variation was documented among groups A and C in addition to between groups B and C. Postoperative spherical equivalent was a significant variation among groups A and C P less than 0.001 and among groups B and C P less than 0.001. Conclusion Visual outcomes were comparable between LASIK, SMILE, and ICL. The three procedures exhibited superior effectiveness, safety, stability, and accuracy in the treatment of moderate and high myopia.

Evaluating the small aperture intraocular lens: depth of focus and the role of refraction and preoperative corneal astigmatism in visual performance.

To evaluate depth of focus (DOF) and visual acuities (VAs) by manifest refractive spherical equivalent (MRSE) and degree of preoperative corneal astigmatism with the IC-8 small aperture intraocular lens (SA IOL) (Apthera). 21 investigational sites in the United States. Prospective, multicenter, open-label, parallel-group, nonrandomized, examiner-masked, 1-year clinical study. Included patients had cataract and ≤1.5 diopters (D) preoperative corneal astigmatism. Patients received either the SA IOL in 1 eye targeted to -0.75 D and a monofocal or monofocal toric IOL in the other targeted to plano (SA IOL group) or bilateral monofocal/monofocal toric IOLs targeted to plano (control group). Monocular and binocular assessments included defocus curves and uncorrected VAs (distance, intermediate, and near) by postoperative MRSE; monocular VAs were assessed by degree of preoperative corneal astigmatism. The SA IOL group (n = 343) achieved 0.82 D additional binocular DOF vs the control group (n = 110), and SA IOL eyes achieved 0.91 D additional monocular DOF over fellow eyes. Across all MRSEs, the SA IOL group achieved monocular uncorrected VAs of 20/40 or better and binocular uncorrected VAs of 20/32 or better across all distances. In addition, SA IOL eyes with higher (1.0-1.5 D) vs lower (<1.0 D) preoperative corneal astigmatism achieved equivalent monocular uncorrected VAs. The SA IOL provides increased DOF vs monofocal/monofocal toric IOLs and consistent monocular and binocular vision across several postoperative MRSEs and up to 1.5 D of preoperative corneal astigmatism, giving patients with cataract and mild astigmatism the potential for an extended range of vision and reliable visual outcomes.

Mapping of chromite occurrence in a meta-ultramafic complex by magnetometric prospecting, Sul-Riograndense Shield (Southern Brazil)

This study presents the use of terrestrial magnetometry method in the characterization of a metamorphic and chromium-mineralized ultramafic body in the São Sepé region (RS). Several serpentinite exposures were recognized in the study area, characterized by a very evident schistosity marked by amphiboles and micas. The most preserved rocks are gray to dark green in color, silky to the touch and with folds and variable fracturing. The chromite present in serpentinites is associated with magnetite, and occurs in the form of small lenses. 1677 reading lines were made perpendicular to the main direction of the meta-ultramafic body, with 25m spacing between measurement points. The magnetometric maps revealed high-intensity anomalies related to meta-ultramafic rocks. 1677 reading lines were made perpendicular to the main direction of the meta-ultramafic body, with 25m spacing between measurement points. The magnetometric maps revealed high-intensity anomalies related to meta-ultramafic rocks. The results revealed the existence of highly magnetic individualized lenses orientated according to NE / SW, related to regional deformation events, with remobilization and mineral reconcentration. The direct relationship between high magnetization and chromite/ferro-chromite concentrations allows relatively detailed mapping of potentially mineralized areas, revealing dimensions more significant than the limits of the meta-ultramafic sequence defined in the geological map. The results indicate that the analytical signal amplitude map is a highly recommended product for planning sampling actions and reserve quantification, improving classical geological mapping.

Criteria for premium intraocular lens patient selection.

To discuss available premium intraocular lenses (IOLs), patient selection, and important considerations for each premium IOL. We review important topics and considerations for premium IOL selection: specifically, toric, extended depth of focus (EDOF), multifocal/trifocal, light adjustable lenses (LALs), and small aperture IOLs. Toric lenses are an excellent option for patients with astigmatism. However, to achieve optimal patient satisfaction, it is critical to account for the ATR astigmatism contribution from the posterior cornea and high angle alphas. Additionally, examining the ocular surface prior to placement of EDOF/multifocal IOLs is important, yet the significance of HOAs on outcomes after implantation still must be elucidated more. Finally, recent studies reveal that the small aperture lens is a good alternative for those with corneal irregularities, and second generation LALs are a great option to achieve target refractions in those with less predictable refractive outcomes, such as in Fuchs' dystrophy or in eyes with previous refractive surgery.

The Impact of Back Optic Zone Design in Orthokeratology on Visual Performance.

To evaluate the visual performance in adolescents undergoing orthokeratology (OrthoK) treatment with two different optical zone diameters (OZDs). This randomized, double-masked, self-controlled prospective study was conducted at Tianjin Eye Hospital (Tianjin, China) in June 2022. Thirty-six eligible schoolchildren were enrolled and fitted with corneal refractive therapy lenses with two sizes of OZDs (5 mm [5OZ] and 6 mm [6OZ]). Each participant was randomized to wear the 5OZ in one eye and the 6OZ in the contralateral eye. Subjective visual quality was assessed using visual acuity, refraction, contrast sensitivity function, and visual symptoms, and the objective optical quality was assessed using ocular higher order aberrations (HOAs) and modulation transfer function (MTF). Thirty-five myopic children completed a 1-month follow-up visit. The 5OZ lens induced significantly smaller treatment zone diameters than the 6OZ lens (P < 0.001). Subjective visual quality did not differ significantly between the two groups. Compared to baseline, aberrations of Z40, coma-like, spherical-like, and total HOAs in both groups increased significantly (P < 0.05). For the 3-mm pupils, spherical aberration in the 5OZ group was significantly higher than that in the 6OZ group (P < 0.05). The MTF value of the 6OZ group was significantly higher than that of 5OZ group for 0.3 and 1.5 cycles per degree for the 3-mm pupils (P = 0.006 and P = 0.026, respectively). However, HOAs or MTF did not differ significantly between the two groups for the 5-mm pupils. The difference induced by varying OZD was significant only in the smaller pupil condition. The selection of OZD in OrthoK designs in real-world patient management should be done while considering individual pupil size. This study revealed that the objective visual quality of small OZD lenses was only slightly affected for the small pupil size.

Devonian Harpetidae from the central and eastern Anti–Atlas, Morocco

The systematics of 37 new species of Devonian Harpetidae from the central and eastern Anti–Atlas Mountains, Morocco, are described. The new material comes from the Dra—Tafilalet region and the province of Tata. A cladistic study was undertaken involving 138 taxa with the objective of assigning the new taxa to the appropriate genera, which are, as far as possible, monophyletic. In order to identify the widespread homoplasy present amongst harpetid taxa, which has proven so problematical for systematics in the past, many additional morphological characters were coded in the data matrix, totaling 111. In addition to the new material, all those described harpetid species from the Devonian and Silurian in which at least 10% of characters could be reliably coded were included in the study. The parsimony analysis using 20 different seeds identified 636 shortest trees; the consensus tree recognised 10 monophyletic clades to accommodate Devonian species. While the node support was weak the topology of the consensus tree is a substantial improvement on those of previous phylogenetic studies which have tended to be pectinate. The new species were assigned to 10 genera. Four genera (Harpes, Lioharpes, Kielania and Eskoharpes) are redefined and Globoharpes is reduced to a junior synonym of Eskoharpes. Three further genera are recognised, Declivoharpes, Fritchaspis and Helioharpes, which have been misinterpreted in the past and the new genera Maghroharpes, Pinnuloharpes and Stoloharpes established. The new species are assigned as follows: to Harpes, H. boudibensis, H. lahceni, H. lentigo, H. oudris, H. prescheri, H. sphenocephalus and H. supercilium; to Lioharpes, L. ammari; L. galea, L. morocconensis, L. saredra, and L. scopulum; to Fritchaspis, F. edgecombei; to Helioharpes, H. aougili; to Kielania: K. tumula; to Eskoharpes, E. sicarius; to Maghroharpes, M. azmamarensis, M. forteyi, M. hammii, M. ihmadii, M. laatchanensis, M. minutipunctus, M. oufatenensis, M. terridus, and M. zguidensis; to Pinnuloharpes, P. apteros, P. chaperon, P. hannabouensis, P haustrum, P. igaouii, P. merzaneensis; P. segaouii. and P. torquis; Stoloharpes, S. calceolus, S. capricornus, S. retiarius, and S. rissaniensis. Decllivoharpes, is also recognised as a genus, although no new species has been assigned to it. The cladogram produced very few synapomorphies and there are no unique diagnostic characters available to determine genera. To assist in the process of assigning species in the future to the correct genera a working guide using combinations of characters and character states used in the study has been prepared. The name Helioharpes perradiatus has been widely used with regard to harpetids from the Anti Atlas. This study shows that this has been a ‘portmanteau’ name for at least three distinct species. All are very different from the type material of H. perradiatus, which was recovered from the Western Meseta to the north of the Atlas Mountains, and has not been found to occur in the Anti-Atlas. The new material figured herein has provided additional information on the eyes of Devonian harpetids of the Anti-Atlas. Typically, each eye lobe has two lenses which vary considerably in shape from species to species and are very different from the symmetrical multi lensed eyes of other Devonian trilobites. Probably in response to environmental changes a small third eye lens appeared for a short time twice, first in the upper Pragian/lower Emsian and then again in the Eifelian. The shape of the Pragian/Emsian lens was circular whereas that of the Eifelian lens was similar to the shape of the two larger accompanying eye lenses.

Research on key technology of cooled infrared bionic compound eye camera based on small lens array

Traditional 2D imaging technologies are limited by the need for a large field of view and their sensitivity to small target motion. Inspired by the characteristics of insect compound eye structure, we propose an infrared bionic compound eye camera based on a small lens array. The camera is composed of 61 small lens arrays mounted on a curved spherical shell and a relay optical system. The imaging device is a high-performance cooled mid-wave infrared detector. This is an innovative design for an infrared biomimetic compound eye camera system that provides a wide field of view and all-day detection capability. Aimed to meet the specified requirements. The optical system achieves a 100% cold-membrane match between the infrared optical system and the cooled detector, and the relay optical system optimizes the large-field aberration by introducing a higher-order aspheric surface and modifying the geometric surface of the lenses. Our entire system enables an observation field angle of 108∘×108∘\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$108^\\circ \ imes 108^\\circ$$\\end{document}. The experiments showed that the image quality of the system is high, each ommatidium was effective within the imaging range of the compound eye camera, resulting in an improved signal-to-noise ratio in various scenes.

Prediction of the small aperture intraocular lens on visual acuity in patients with keratoconus.

To investigate the impact of corneal higher-order aberrations (HOAs) on predicted corrected distance visual acuity (CDVA) in patients with keratoconus at varying simulated pupil apertures. Ophthalmology Clinics, Medical University of South Carolina, Charleston, South Carolina. Retrospective chart review study. 56 eyes with keratoconus were examined using Scheimpflug tomography during routine examinations before medical intervention. The severity of keratoconus was graded using the Amsler-Krumeich classification. Zernike analysis was used to obtain corneal aberrations using simulated pupil diameters of 6 mm, 4 mm, and 2 mm. These data were extrapolated to obtain the total root mean square HOAs for a 1.6 mm simulated pupil to evaluate the potential effect of a small aperture intraocular lens (IOL). Correlation analysis was used to study the impact and relative contributions of HOAs on CDVA. Convolution of HOAs from OPD-Scan III provided a clinical method to predict CDVA with different simulated pupil sizes in corneas with irregular astigmatism. There were statistically significant positive correlations between photopic CDVA and the magnitude of total and individual (coma, spherical aberration, and trefoil) HOAs in this cohort of keratoconus participants. A keratoconus case with the small aperture IOL confirms the improvement in vision due to the pinhole effect. The small aperture IOL is expected to markedly reduce aberrations in patients with keratoconus up to Amsler-Krumeich class 4 severity to levels consistent with the levels seen in healthy patients. Convolution of corneal HOAs with the Early Treatment Diabetic Retinopathy Study chart provides a useful simulation of the impact of pinhole optics in aberrated eyes.

Longitudinal study of microphthalmia in connexin 50 knockout mice using spectral-domain optical coherence tomography.

Connexin 50 (Cx50) mediated signaling is essential for controlling the lens growth and size. Cx50 mutations cause microphthalmia, smaller lenses, and cataracts in humans and animals. These ocular defects have never been investigated in live Cx50 mutant mice by using non-invasive imaging techniques. Here, we report a longitudinal study of the ocular defects in Cx50 knockout (Cx50KO) mice from the ages of 3 weeks to 12 months by using spectral-domain optical coherence tomography (SD-OCT). The anterior chamber depth (ACD), lens thickness (LT), vitreous chamber depth (VCD), and axial length (AL) were measured along the visual axis and adjusted with corresponding refractive indices. The SD-OCT image data confirm age-related reductions of LT and AL in live Cx50KO mice compared to age-matched wild-type (WT) controls, and the reduction values are comparable to the in vitro measurements of Cx50KO eyeballs and lenses reported previously. Moreover, reductions of ACD were observed in Cx50KO mice at all ages studied while VCD changes are statistically insignificant in comparison to the WT controls. Therefore, Cx50KO's microphthalmia with small lens is selectively associated with delayed ACD development but not the vitreous formation. This work supports the notion that lens size and/or growth is important for anterior chamber development.

Miniaturization design of laser detection device for naval gun composite fuse

Naval gun weapons are the only weapon system on board that can undertake various combat tasks such as shore fire support, sea attack, air defense and missile defense, and rapid response to emergencies. A new type of naval gun laser-radio composite fuse(naval gun composite fuse) is proposed to address the issue of naval gun fuses being susceptible to interference and failure in a single radio proximity system. This improves the multiple operational effectiveness of naval guns and the adaptability of naval gun ammunition to electromagnetic and other interference environments. In response to the limitation of small size of naval gun fuses, the overall structure and miniaturized laser detection device were designed separately. Firstly, a miniaturized 4-channel narrow pulse high repetition frequency laser detection method with uniform forward circumferential distribution is adopted to achieve compatibility with the original naval gun fuse structure, the simulation results indicate that the structural deformation and strength meet the requirements. Secondly, by designing a laser emission collimating lens that is glued together with a small spherical lens and a small concave cylindrical mirror, the outer envelope size is only Φ5x3mm. The simulation results show that at a distance of 20mm from the laser emission window, the spot diameter is 0.66mm and the divergence angle is 1.9 °, achieving good laser collimation and miniaturization of the emission optical system. Finally, the receiving optical system reduces its volume by adding a receiving objective and a field mirror. The effective aperture of the receiving objective is 10mm, the diameter of the field mirror is 5mm, the focal length is 11.1mm, and the receiving field angle is 5 °. The simulation results show that the laser spot radius on the photosensitive surface of the photodetector is 0.06mm, which meets the requirements of photodetectors.

Influence of back optic zone diameter on corneal morphology with orthokeratology lenses

ObjectiveThis study aimed to compare the changes in corneal morphological characteristics in corneal topography assessments performed after wearing orthokeratology (OK) lenses with different back optic zone diameters (BOZDs). These changes included the change ratios of the apical corneal power (ACP), the maximum relative corneal refractive power (mRCRP), and the treatment zone diameter (TZD). MethodsData from 133 children with myopia (average age 9.50 ± 1.23 years) treated at Fudan University Eye and Ear, Nose, and Throat Hospital were retrospectively analyzed. All participants wore the same brand of tangent-design OK lens (corneal refractive therapy, CRT). According to the BOZD, the patients were divided into two groups, of 5.0 and 6.0 mm BOZD, respectively. Corneal topography was analyzed at baseline, as well as 1 day, 1 week, and 1 month after wearing the lenses, and the change ratios of ACP, mRCRP, and TZD were compared between the two groups. ResultsThe change ratio of the ACP did not differ significantly between the BOZD 5.0 and 6.0 groups after 1 day or 1 week of lens wear (P = 0.170 and P = 0.113, respectively). However, after 1 month of lens wear, the change ratio of the ACP in the BOZD 5.0 group was significantly larger than that in the BOZD 6.0 group (P < 0.001). After 1 month of lens wear, the mRCRP along the horizontal and vertical meridians was higher (P < 0.05) and the TZD was significantly smaller (P < 0.001) in the BOZD 5.0 group than in the BOZD 6.0 group. ConclusionIn CRT OK lenses, a small BOZD lens can produce faster corneal shaping, a larger mRCRP, and a smaller TZD, which may have a better effect on slowing ocular axial length elongation. The lens parameters are also a factor affecting the TZD.

Analytical solutions for freshwater lenses in stratified riparian aquifers

Analytical solutions for defining stable freshwater lenses within saline riparian aquifers (“riparian lenses”) are largely limited to homogenous aquifers. However, real-world riparian aquifers typically consist of a surficial layer of low-permeability soils or deposits, the impact of which on the occurrence of riparian lenses has not been investigated. This study develops steady-state, sharp-interface analytical solutions for riparian lens shape and saltwater discharge in a two-layered riparian aquifer. The developed analytical solutions are verified by sand tank experiments and numerical simulations, showing good agreement. The sensitivity analysis based on the proposed analytical solutions suggests that aquifer stratification (i.e., considering a low-permeability layer overlying a high-permeability layer) leads to larger lenses in head-controlled systems (i.e., with the inland constant-head boundary) but smaller lenses in flux-controlled systems (i.e., with the inland constant-flux boundary), compared to the scenario of a homogenous aquifer. The surficial layer with hydraulic conductivity only an order of magnitude lower than the underlying high-permeability layer would have a pronounced effect on lens extent and volume. Importantly, the results suggest that the presence of the surficial low-permeability layer may lead to the outcropping of the groundwater table, favoring the occurrence of saline groundwater seepage near the edge of the river valley (i.e., a phenomenon reported by the field survey of the Murray River floodplains in South Australia). The analytical solution presented in this study can be used to provide a preliminary assessment of riparian lenses in saline stratified aquifers, expanding the applicability of analytical methods to more realistic riparian settings.

DiffraPy: An open-source Python software for seismic diffraction imaging

Seismic diffraction events, often overlooked as noise in conventional seismic imaging methods, contain valuable high-resolution information about subsurface structures and heterogeneities. Furthermore, the diffractive component of the wavefield is masked by the stronger reflection events. Although the literature presents innovative methods for separating diffracted events from the total wavefield, there are currently limited options of open-source alternatives in seismic diffraction processing and imaging. In this study, we introduce DiffraPy, an open-source Python package specifically designed for performing both conventional and diffraction-oriented migrations. The main workflow involves implementing an anti-stationary phase filter in the Kirchhoff migration for enhancing energy outside the Fresnel zone. Additionally, we propose using the semblance matrix obtained from the dip field calculation as an additional weight in conventional migration. The code provides functionality for forward modeling seismic data, allowing for new testing and experimentation. We demonstrate the general workflow of the code using a toy model and evaluate its capabilities on a synthetic salt model. In both cases, the program successfully suppressed the majority of reflected energy in the diffraction-oriented image. The final image highlights the responses of small lenses, discontinuities, and faults, providing valuable insights into the subsurface for interpretation. Despite the method sensitivity to variations in the correct velocity model, we demonstrate that our code is capable of imaging diffractors even when utilizing incorrect migration velocities of up to 5%. Our wavenumber analysis reveals the diffraction image preservation of smaller wavelengths, indicating higher resolution compared to conventional products. Future implementations may include extension to 3D datasets and improve the computational efficiency of our code. We expect our code to offer the geosciences community the first freely accessible and well-documented Python alternative for testing, reproducing, and exploring diffraction imaging examples.

Quantifying salinity in heterogeneous coastal aquifers through ERT and IP: Insights from laboratory and field investigations

The lithological and stratigraphical heterogeneity of coastal aquifers has a great influence on saltwater intrusion (SI). This makes it difficult to predict SI pathways and their persistence in time. In this context, electrical resistivity tomography (ERT) and induced polarization (IP) methods are receiving increasing attention regarding the discrimination between saltwater-bearing and clayey sediments. To simplify the interpretation of ERT data, it is commonly assumed that the bulk conductivity mostly depends on the conductivity of pore-filling fluids, while surface conductivity is generally disregarded in the spatial and temporal variability of the aquifers, particularly, once the aquifer is affected by the presence of saltwater. Quantifying salinities based on a simplified petrophysical relationship can lead to misinterpretation in aquifers constituted by clay-rich sediments. In this study, we rely on co-located data from drilled boreholes to formulate petrophysical relationships between bulk and fluid conductivity for clay-bearing and clay-free sediments. First, the sedimentary samples from the drilled wells were classified according to their particle size distribution and analyzed in the lab using spectral IP in controlled salinity conditions to derive their formation factors, surface conductivity, and normalized chargeability. Second, the deduced thresholds are applied on the field to distinguish clay-bearing sediments from brackish sandy sediments. The results are validated with logging data and direct salinity measurements on water samples. We applied the approach along the Luy River catchment and found that the formation factors and surface conductivity of the different unconsolidated sedimentary classifications vary from 4.0 to 8.9 for coarse-grained sand and clay-bearing mixtures, while normalized chargeability above 1.0 mS.m−1 indicates the presence of clay. The clay-bearing sediments are mostly distributed in discontinuous small lenses. The assumption of homogenous geological media is therefore leading to overestimating SI in the heterogeneous clay-bearing aquifers.

On the Asymptotic Evaluation of the Radiative Near-Field in Resonant Leaky-Wave Antennas Using a Non-Uniform Phase Center: Application to Small Lenses

On the Asymptotic Evaluation of the Radiative Near-Field in Resonant Leaky-Wave Antennas Using a Non-Uniform Phase Center: Application to Small Lenses

Optimizing groundwater pumping in small island groundwater lenses: An analytical approach

For residents living on small islands, groundwater serves as their primary source of freshwater, which exists in the form of a freshwater lens floating above denser seawater. Previous research on optimizing pumping strategies in freshwater lenses focused on pumping from fixed wells using numerical models, and optimal well locations have not been explored. In this study, we analyze pumping optimization for both fixed well cases and moving well cases in a rectangular island using an analytical approach. This approach allows for a clear understanding of the relationship between hydrogeological parameters and optimization results. For fixed well cases, we provide an analytical solution for the critical pumping rate of each well. For moving well cases, Bayesian optimization is employed to efficiently search the extensive space of possible well locations and identify the critical pumping rate. Our results reveal that the well location has a substantial impact on the critical pumping rate in the fixed well cases, indicating that investigating the optimization of well placement is essential. In the discussion of the moving well cases, the maximum total pumping rate of a pumping well network is independent of hydraulic conductivity, and the critical pumping percentage relative to total recharge is independent of both hydraulic conductivity and recharge. The distribution of optimized well locations for islands with a fixed aspect ratio but different sizes follows the same pattern. In the moving well cases, different solutions can achieve the same maximum pumping rate, especially when multiple wells are involved. In addition, our approach is applicable to scenarios where new wells are added to an existing well system. Our solutions and findings significantly contribute to a deeper understanding of the hydraulic performance of pumping activities from freshwater lenses and offer valuable insights for developing more sustainable and robust groundwater management strategies in small islands.

Reduction of lens size in PAX6-related aniridia

Heterozygous mutation of PAX6 in humans leads to congenital aniridia (OMIM 106210) which is typified by congenital iris and foveal defects, and later onset glaucoma, aniridic keratopathy, and cataract. Mice heterozygous for Pax6 mutations phenocopy many aspects of aniridia including the iris defects, keratopathy and cataract, although Pax6 mutant mice have small lenses, a phenotype which is not typically reported in human aniridia, perhaps due to difficulties in measuring lens diameter during typical ophthalmic examinations as the lens periphery is shielded by the iris. In order to overcome this, records of patients diagnosed with congenital aniridia between April 2015 and May 2021 at the Necker-Enfants Malades Hospital, and genetically confirmed with a disease-causing PAX6 variant, were retrospectively reviewed for those with normal axial length whose iris defects allowed visualization of the lens margins and corneal diameter to allow calculation of a lens/corneal diameter ratio. This value was compared with values obtained from a cohort of patients with Sjödell grade IV oculocutaneous albinism type 1 (OCA1; OMIM 203100) which allowed visualization of the lens periphery via iris transillumination. This analysis revealed that patients with congenital aniridia had a significantly lower lens/corneal ratio when compared to those with albinism, suggesting that humans haploinsufficient for PAX6, like mice, rats, frogs, and zebrafish, exhibit reductions in lens size.