Low Density Research Articles

Harmful Effects on the Hippocampal Morpho-Histology and on Learning and Memory in the Offspring of Rats with Streptozotocin-Induced Diabetes

Learning alterations in the child population may be linked to gestational diabetes as a causal factor, though this remains an open and highly controversial question. In that sense, it has been reported that maternal hyperglycemia generates a threatening condition that affects hippocampal development in offspring. The pyramidal cells of the CA3 subfield, a key structure in learning and memory processes, are particularly important in cognitive deficiencies. We evaluate the effect of the hyperglycemic intrauterine environment on hippocampal histomorphometry in offspring, correlating it with spatial learning and memory, as well as the morphology of dendrites and spines in 30-day-old pups (P30). The maternal hyperglycemia affected the body weight, height, and brain size of fetuses at 21 days of gestation (F21), newborn pups (P0) and P30 pups from diabetic rats, which were smaller compared to the control group. Consequently, this resulted in a decrease in hippocampal size, lower neuronal density and cytoarchitectural disorganization in the CA3 region of the hippocampus in the offspring at the three ages studied. The behavioral tests performed showed a direct relationship between morpho-histological alterations and deficiencies in learning and memory, as well as alterations in the morphology of the dendrites and spines. Therefore, knowing the harmful effects caused by gestational diabetes can be of great help to establish therapeutic and educational strategies that can help to improve learning and memory in children.

Paddy straw biochar amended sediment enhances pond productivity, growth and physiological profile of Penaeus vannamei cultured in inland saline nursery ponds.

The growing interest in commercial Inland saline aquaculture has taken momentum across the globe due to the available technologies for aquaculture and the abundant resources of saline groundwater. However, the critical problems in inland saline ponds are degraded soil and imbalanced or deficient nutrients. To address these issues, a 75-day experiment was conducted to explore the effects of Paddy Straw Biochar (PSB) as a sediment amendment on sediment quality, water characteristics, growth parameters, and the well-being of Penaeus vannamei reared in inland saline environments. PSB was applied to the nursery ponds at 1 ton/hectare (Treatment, T1) and 2 ton/hectare (Treatment, T2). The findings of water quality parameters showed a significant increase in K+ and Mg++ with a decrease in ammonia-N levels in biochar-applied ponds. Similarly, the addition of biochar to ponds (T2) resulted in improved sediment characteristics with enhanced water holding capacity (24.75%), increased soil organic carbon content (77.94%), pH levels (0.37 units), cation exchange capacity (43.15%), available potassium (16.3%), and lower bulk density (12.61%) compared to ponds subjected to control conditions at the end of the experiment. Over the experiment, improvements in sediment and water quality parameters followed the T2 > T1 > control trend. Growth characteristics showed a significant rise in the percentage of weight gain (12.398 ± 0.12), SGR (11.80 ± 0.01% day-1) and PER (2.39 ± 0.01) with reduced FCR (1.19 ± 0.00) in biochar-treated ponds (T2), followed by T1 and control. The digestive enzyme activity (amylase) and metabolic enzymes like hepatopancreatic alanine aminotransferase (ALT) and muscle ALT activities were significantly higher in shrimps raised in the biochar-applied ponds. On the other hand, the oxidative stress enzyme superoxide dismutase (SOD) in gills, muscles, and hepatopancreas (HP) exhibited lower values, suggesting reduced oxidative stress due to the biochar amendment of the pond sediment. Overall, the study recommends incorporating PSB at a rate of 2 t/ha into nursery pond sediment to enhance water quality, physiological status, and the growth of P. vannamei juveniles. Moreover, this approach improves soil and water characteristics in saline soils, making it an effective culture practice in degraded environments.

Dynamic response characteristics of proton exchange membrane fuel cell during transient loading: An experiment study

The dynamic performance of Proton Exchange Membrane Fuel Cell (PEMFC) is crucial for safe and efficient operation and remains a major barrier to commercialization. In this paper the dynamic response characteristics of PEMFC under serpentine flow field (SFF) and parallel flow field (PFF) are discussed. The effects of current loading, operating pressures, anode and cathode stoichiometric ratios, as well as operating temperatures on the dynamic response characteristics of PEMFC are systematically studied through experimental methods. Furthermore, the principle and mitigation strategies for voltage undershoot are investigated. It shows that lower current density, higher back pressure and higher temperature are benefit to alleviate voltage undershoot. Compared with the SFF, the Second-stage time delay of PFF is shortened by 9.2 s, the VU is decreased by 17.27 mV, and the energy loss is reduced by 0.71%. Moreover, Pearson correlation coefficient is proposed to evaluate the correlation between index and PEMFC performance.

Performance Analysis of JL-FinFET with Varied Non-Uniform Doping Concentrations, Fin Height and Fin Width using Device Simulator

With the growth of the MOSFET technology, the size of the transistor becomes smaller which can lead to Short-Channel Effects (SCEs). In order to address the SCEs, multi-gate transistor such as Fin Field-Effect Transistor (FinFET) has been invented. Meanwhile, it is found that the conventional transistor with junctions also has its drawbacks and limitations due to the decrease in the gate length. The SCEs can occur and affect the overall performance of the device with lower switching times and lower current density . In order to address these limitations, new structure of transistor without junction known as a junctionless (JL) transistor has been proposed. In this work, the impact of uniform versus non-uniform doping concentrations, fin height (Hfin) and fin width (Wfin) in JL-FinFET were investigated by using Technology Computer Aided Design (TCAD) Tools. It was found that non-uniform doping concentration of 4 x1018 cm-3 for the source/drain and of 4 x1017 cm-3 for the channel, together with Hfin of 20 nm and Wfin of 4 nm provide the best electrical performance of Ioff = 6.45 x10-17 A, Ion = 6.14 x10-6 A, Ion/Ioff = 9.52 x1010 and DIBL = 11 mV/V. The outcome of this research work can be used as a basis to understand JL-FinFET biosensors for medical applications and more complex JL structures.

Comparative evaluation of hepatosteatosis in patients with type 2 diabetes mellitus using non-contrast abdominal CT and laboratory findings

Aim: This study aims to underscore the significance of employing multiple parameters from non-contrast abdominal CT scans for the assessment of hepatosteatosis in patients with Type 2 Diabetes Mellitus. Methods: Non-enhanced Computed Tomography of the diabetic subjects were analyzed. Control subjects were selected from non-diabetic patients who had undergone abdominal tomography within the same period. The craniocaudal length of the liver and liver, spleen, pancreas densities, and epicardial adipose tissue were measured. Additionally, patient demographics and laboratory values were retrospectively obtained. Results: The craniocaudal length of the liver was significantly greater in the diabetes mellitus group compared to the control group (168.3 ± 17.2 mm vs 152.3 ± 14.8 mm, p < 0.001). Hepatosteatosis was observed in 22 individuals with diabetes mellitus, whereas only one participant in the control group had this condition (p < 0.001). The diabetes mellitus group exhibited significantly lower median liver density (p < 0.001), liver-spleen density ratio (p = 0.004), pancreatic head density (p = 0.001), and pancreatic body density (p = 0.013). Additionally, the average thickness of epicardial adipose tissue was markedly higher in the diabetes mellitus group compared to the control group (8.1 ± 1.9 mm vs 4.9 ± 1.1 mm, p < 0.001). Conclusions: These data indicate an association between hepatosteatosis and increased epicardial adipose tissue thickness, liver and pancreatic densities in individuals with diabetes mellitus. These findings suggest that non-contrast abdominal CT findings such as epicardial adipose tissue thickness and relevant laboratory tests may aid in evaluating metabolic disorders and fat accumulation in diabetic patients.

Improving seedling recruitment and dryland restoration using a targeted fungicide seed coating

The success of seeding projects in dryland systems is sporadic, with failure primarily driven by low seedling emergence and survival. This sporadic nature is influenced by a litany of biotic and abiotic factors that act in synergy to reduce recruitment success. These factors include erratic seasonal weather patterns, competition, predation, plant material selection, and restoration strategies. While some events are unpredictable and uncontrollable, others may be mitigated through thoughtful deliberation. Pathogenesis from soil‐ and seed‐borne fungi is one form of predation that can decrease restoration success. Fungicide seed coatings are technologies used in the agriculture industry to mitigate fungal pathogens, yet these technologies are novel to wildland seeding. We evaluated the ability of a fungicide seed coating to improve bluebunch wheatgrass (Pseudoroegneria spicata) recruitment across a broad range of sites and determined how soil and climate affected seed treatments across six sites over 650 linear kilometers of sagebrush‐steppe habitat in the Great Basin, United States. Treatment effects varied by site; however, on average, the fungicide treatment increased germination by 16%, emergence by 42%, and juvenile plant establishment by 60%. Fungicide seed treatments had a greater effect on seedling emergence in soils with lower pH, reduced wet‐thermal accumulation during the winter, lower bulk density, and higher organic matter content. Most notably, the fungicide seed treatment resulted in higher plant establishment when emerged seedlings were exposed to longer periods of available soil moisture. Fungicide seed treatments can improve the establishment of native bunchgrasses, when soil and climate regimes are considered.

Heterogeneity of metabolic phenotypes in adolescent boys with obesity due to excess calories

The aim of the study was to determine the heterogeneity of metabolic parameters in teenage boys diagnosed with “obesity due to excess calories” using cluster analysis. Materials and methods. One hundred and twenty-three randomly selected patients aged 14 to 17 years diagnosed with “obesity due to excess calories” were examined. The statistical analysis included descriptive and analytical methods, in particular aimed to identify clusters of biochemical indicators, including serum fasting glucose level, insulin level, total cholesterol level, low density lipoproteins (LDLP), very low-density lipoproteins (VLDL), high density lipoproteins (HDLP) and triglycerides. Results. Two clusters of observations have been identified. The first cluster consisted of 72 patients (58.5%) having fasting glucose levels slightly below average, insulin levels above average, total cholesterol, triglycerides, LDLP and VLDL above average, and HDLP levels below average (“metabolically unhealthy” obesity). The second cluster included 51 teenagers (41.5%) who presented with opposite trends in metabolic characteristics (“metabolically healthy” obesity). The adolescents from the first cluster were slightly older, had higher body mass, body mass index (BMI) and z-BMI scores, and higher HOMA-IR scores. Arterial hypertension and non-alcoholic fatty liver disease were diagnosed statistically significantly more frequently in adolescents from this cluster. Conclusion. Teenage boys with obesity are a heterogeneous group in terms of the values of major metabolic indicators.

Low PD-L1 expression, MAP2K2 alterations, and enriched HPV gene signatures characterize brain metastases in head and neck squamous cell carcinoma

BackgroundBrain metastasis (BM) is a rare but severe complication of head and neck squamous cell carcinoma (HNSCC), with limited knowledge of molecular characteristics and immunogenicity.MethodsWe analyzed 61 cases of HNSCC-BM from three academic institutions (n = 24) and Foundation Medicine Inc (FMI, n = 37). A subset of cases underwent next-generation sequencing, multiple immunofluorescence, and proximity ligation sequencing. Gene enrichment analysis compared alterations in FMI BM samples (n = 37) with local samples (n = 4082).ResultsDemographics included: median age of 59 years, 75% male, 55% current/former smokers, 75% oropharyngeal primary, and 67% human papillomavirus (HPV) +. ATM (54%), KMT2A (54%), PTEN (46%), RB1 (46%), and TP53 (46%) were frequently altered in BM samples from academic centers (62% HPV/p16+). Structural rearrangements ranged from 9 to 90 variants by proximity ligation sequencing. BMs had low densities of CD8+, PD-1+, PD-L1+, and FOXP3 + cells, and 92% had PD-L1 combined positive scores < 1%. CDKN2A (40.5%), TP53 (37.8%), and PIK3CA (27.0%) alterations were common in the FMI BMs (51% HPV+). MAP2K2 alterations and HPV + signature were enriched in FMI BMs compared to local tumors (11.8% vs. 6.4%, P = 0.005 and 51.25% vs. 26.11%, P = 0.001 respectively), and pathogenic TSC1 inactivating mutations were enriched in local tumors (67.3% vs. 37.8%, P = 0.008). Median overall survival from BM diagnosis was 9 months (range 0–27).ConclusionsHNSCC patients with BM frequently have oropharyngeal primary sites and are HPV+. Common molecular alterations in BM samples, including targetable PIK3CA and ATM, were identified. MAP2K2 alterations were enriched and densities of immune cells were low, highlighting potential targets for further research and immunotherapy considerations.

Single Nucleotide Polymorphisms and Insertion/Deletion Variation Analysis of Octoploid and Decaploid Tropical Oil Tea Camellia Populations Based on Whole-Genome Resequencing

Oil tea camellia (Camellia spp.) is an important woody oil crop with a high nutritional and economic value. Whole-genome resequencing (WGR) technology can provide an in-depth understanding of the genetic background of this plant as well as a reference for breeding research, germplasm resource conservation, and genetic modification. In this study, we analyzed SNP and InDel variations in 49 individual oil tea camellia germplasm samples collected from five populations located in three provinces of China: Hainan, Guangdong and Guangxi. The samples were analyzed through WGR after the ploidy of the samples was determined through flow cytometry. A total of 239,441,603 high-quality single nucleotide polymorphisms (SNPs) and 23,510,374 high-quality insertion/deletion variation sites (InDels) were obtained. The distribution of SNPs and InDels in different functional regions differed significantly, with a high density of variations in non-coding regions, such as intergenic regions and introns, and a relatively low density of variations in coding regions. Transition was the main type of SNP variation. A population genetic diversity analysis revealed that the sampled oil tea camellia populations exhibited a high genetic diversity and extensive genetic variation. The genetic diversity of the oil tea camellia populations in the Hainan region was higher than inland regions. This study also determined the genetic diversity of and variations between octoploid and decaploid oil tea camellia in the tropics and between Hainan-based and inland oil tea camellia. Such findings provide a reference for the conservation of germplasm resources and the genetic modification of oil tea camellia.

Evaluation of antibodies to oxidized low-density lipoprotein in children with obesity of different degrees

Introduction. The interest in the study of anti-oxidized low-density lipoproteins (anti-oxLDL) is due to their association with the development and progression of atherosclerosis and metabolic syndrome. Purpose of the study. To study the level of antibodies of oxidized low-density lipoproteins (anti-oxLDL) in serum in obese children. Materials and Methods. 76 children aged 5 to 17 years participated in the study. A standard objective and laboratory examination was performed, including physical and sexual development, lipidogram and anti-oxLDL levels. To assess anthropometric data, the standard deviation coefficient was calculated using the Auxology application. The parameters of fat metabolism were determined according to the data of blood biochemical analysis. The content of anti-oxLDL was determined by immuno-enzymatic analysis using test kits “Biomedica”. Results. According to the results of the examination the patients were divided into three groups: group 1 included 36 children with constitutional-exogenous obesity and increased level of anti-oxLDL, group 2-30 patients with constitutional-exogenous obesity and normal level of anti-oxLDL, group 3-10 healthy children. The level of antibodies to oxidized low density lipoproteins (oxLDL) in obese children is 11.6 times higher compared to healthy children. The antibody titer in prepubertal children is 2206 [1809;2603] IU/mL, and in adolescents it is 1505.5 [1109;1902] IU/mL. The highest values of anti-oxLDL levels were observed in patients with 1st degree obesity 2623 [2245;3001] IU/mL and 3rd degree obesity 2914.5 [2678;3151] IU/mL. Conclusion. High of anti-oxLDL levels were found in pre-pubertal children with obesity, especially in 1st and 3rd degree obesity. In obese children, the level of anti-oxLDL has a direct correlation with the duration of the underlying disease and the increase in low-density lipoprotein (LDL) levels. Further studies are needed on the role of anti-OCOLDL as an early predictor of atherosclerosis in clidren with obesity.

Investigation of defect states in AlGaN/GaN high electron mobility transistors by small-signal admittance analysis

We have performed a small-signal admittance analysis to extract trap parameters in an AlGaN/GaN high electron mobility transistor-on-Si. Whereas the admittance in the accumulation- and depletion-bias regimes is primarily due to the interface traps, the admittance near the threshold voltage and below is due to mono-energetic traps inside GaN. The density extracted for threading dislocation-related 1D traps at ≈0.22 eV below the GaN conduction band edge is similar to that previously reported by reverse-biased gate leakage analysis of the analyzed device. Our analysis suggests additional 1D traps of comparatively lower density ≈4×1014cm−3 but considerably large capture cross section ≈8×10−14cm2 in the GaN layer at ≈0.31 eV below the conduction band. The AlGaN trap density is considerably larger near the AlGaN/GaN interface than in the bulk AlGaN. The AlGaN traps mainly contribute to the voltage stretch; their admittance contribution is negligible. Gate leakage dominates the conductance at lower frequencies.

Transcriptional pathways of terminal differentiation in high- and low-density blood granulocytes in sepsis

BackgroundTrauma and infection induce emergency granulopoiesis. Counts of immature granulocytes and transcriptional pathways of terminal granulocytic differentiation in blood are elevated in sepsis but correlate with disease severity. This limits their performance as sepsis biomarkers in critically ill patients. We hypothesized that activation of these pathways in sepsis is attributable to immature low-density (LD) rather than mature high-density (HD) granulocytes.MethodsWe included patients with sepsis and systemic inflammatory response syndrome (SIRS) of comparable disease severity, and additionally septic shock, on intensive or intermediate care unit admission. Blood granulocyte isolation by CD15 MicroBeads was followed by density-gradient centrifugation. Flow cytometry was used to determine counts of developmental stages (precursors) and their relative abundancies in total, HD, and LD granulocytes. Five degranulation markers were quantified in plasma by multiplex immunoassays. A set of 135 genes mapping granulocyte differentiation was assayed by QuantiGene™ Plex. CEACAM4, PLAC8, and CD63 were analyzed by qRT-PCR. Nonparametric statistical tests were applied.ResultsPrecursor counts appeared higher in sepsis than SIRS but did not correlate with disease severity for early immature and mature granulocytes. Precursor subpopulations were enriched at least ten-fold in LD over HD granulocytes without sepsis-SIRS differences. Degranulation markers in blood were comparable in sepsis and SIRS. Higher expression of early developmental genes in sepsis than SIRS was more pronounced in LD and less in HD than total granulocytes. Only the cell membrane protein encoding genes CXCR2 and CEACAM4 were more highly expressed in SIRS than sepsis. By qRT-PCR, the azurophilic granule genes CD63 and PLAC8 showed higher sepsis than SIRS levels in LD granulocytes and PLAC8 also in total granulocytes where its discriminatory performance resembled C-reactive protein (CRP).ConclusionsTranscriptional programs of early terminal granulocytic differentiation distinguish sepsis from SIRS due to both higher counts of immature granulocytes and elevated expression of early developmental genes in sepsis. The sustained expression of PLAC8 in mature granulocytes likely accounts for its selection in the whole blood SeptiCyte™ LAB test. Total granulocyte PLAC8 rivals CRP as sepsis biomarker. However, infection-specific transcriptional pathways, that differentiate sepsis from sterile stress-induced granulocytosis more reliably than CRP, remain to be identified.

Breast cancer secretes anti-ferroptotic MUFAs and depends on selenoprotein synthesis for metastasis.

The limited availability of therapeutic options for patients with triple-negative breast cancer (TNBC) contributes to the high rate of metastatic recurrence and poor prognosis. Ferroptosis is a type of cell death caused by iron-dependent lipid peroxidation and counteracted by the antioxidant activity of the selenoprotein GPX4. Here, we show that TNBC cells secrete an anti-ferroptotic factor in the extracellular environment when cultured at high cell densities but are primed to ferroptosis when forming colonies at low density. We found that secretion of the anti-ferroptotic factors, identified as monounsaturated fatty acid (MUFA) containing lipids, and the vulnerability to ferroptosis of single cells depends on the low expression of stearyl-CoA desaturase (SCD) that is proportional to cell density. Finally, we show that the inhibition of Sec-tRNAsec biosynthesis, an essential step for selenoprotein production, causes ferroptosis and impairs the lung seeding of circulating TNBC cells that are no longer protected by the MUFA-rich environment of the primary tumour.

Inclusion of Selected Spices in Wistar Rats Diets: Effects on their Heart Functions

The effects of extracts of Aframomum danielli, rough skin plum and country onion on the heart functions of albino wistar rats were evaluated. The rats’ diets were substituted with these spices at 5%, 10% and 15% inclusions, respectively; feeding duration was 28 days. At intervals of 7 days, their blood was taken and analysed for triglycerides, total serum cholesterol, low density lipoproteins and high density lipoprotein cholesterol to ascertain the heart functions of the wistar rats. The values obtained from these tests showed that the triglyceride, total serum cholesterol and low density cholesterol in the blood of test animals reduced from 180.4 mg/dl to 163.87 mg/100g, 136.93 mg/dl to 130.00 mg/dl, and 77.92 mg/dl to 75.74 mg/dl, respectively, while the high density lipoproteins cholesterol in the blood of the test animals increased from 24.10 mg/dl to 28.73 mg/dl. Despite the increase in the HDL in the blood of the test animals, all the mean concentrations of high density lipoprotein (HDL) obtained in this study were found to be very low as MedlinePlus (2007) reported that 60 mg/dl or above HDL helps to protect the heart against diseases. Hence, constant use of these spices is recommended to help boost the HDL level and help curb any possible means of heart disease.

Upper Bound for the Ground State Energy of a Dilute Bose Gas of Hard Spheres

We consider a gas of bosons interacting through a hard-sphere potential with radius a\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathfrak {a}$$\\end{document} in the thermodynamic limit. We derive an upper bound for the ground state energy per particle at low density. Our bound captures the leading term 4πρa\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$4\\pi \\rho \\mathfrak {a}$$\\end{document} and shows that corrections are smaller than Cρa(ρa3)1/2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$C \\rho \\mathfrak {a} (\\rho {{\\mathfrak {a}}}^3)^{1/2}$$\\end{document}, for a sufficiently large constant C>0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$C > 0$$\\end{document}. In combination with a known lower bound, our result implies that the first sub-leading term to the ground state energy of a dilute gas of hard spheres is, in fact, of the order ρa(ρa3)1/2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\rho \\mathfrak {a}(\\rho {{\\mathfrak {a}}}^3)^{1/2}$$\\end{document}, in agreement with the Lee–Huang–Yang prediction.

Theoretical Investigation of the Reaction of O(1D) with Formamide.

Carbamic acid (H2NCOOH) is a small organic molecule that is terrestrially unstable in condensed phases under ambient conditions but could survive in the low densities and temperatures of the interstellar medium. In this work, the reaction of formamide (H2NCOH) and electronically excited oxygen atoms in the 1D state, namely, O(1D), has been investigated computationally to determine the feasibility of carbamic acid production. Geometries for carbamic acid and other potential reaction products have been calculated, as well as all pertinent transition states. In addition, harmonic and anharmonic frequency calculations were performed to determine quartic and sextic centrifugal distortion constants for all products. This work enables spectroscopic predictions that can guide the experimental search for carbamic acid. Presented here are the calculations, geometries, molecular constants, and spectral predictions for possible products of the reaction between formamide and O(1D), as well as a discussion of which products are favored.

A Novel Platform and Workflow for Underwater Photogrammetry Surveys

Abstract. Underwater photogrammetry has gained popularity for creating three-dimensional (3D) maps and ortho-images of marine environments as compared to traditional echosounder surveys, they can be more cost-effective at creating high-resolution 3D models, and orthoimages are usually more informative than acoustic backscatter maps. This paper builds on previous work by the authors that developed an underwater image-capturing platform with several additional sensors, including GNSS, IMU, pressure depth sensor and single beam echosounder. This study aims to analyse the impact of calibration and sensor data integration into the photogrammetric processing workflow. The tests were performed using two underwater sites. The low-cost device's pressure sensor and tide station data outperform GNSS PPK-derived heights. Furthermore, it was observed that incorporating IMU motion sensor data did not improve the processing results. Additionally, utilising the echosounder point cloud proves valuable for enhancing the overall quality of the survey. Despite its lower density, it serves a dual purpose by validating the photogrammetry dataset and, more importantly, can be employed for correcting DSM height. This study further underlined the importance of reliable camera calibration for accurate 3D reconstruction.

Elucidating the Performance Limitations of a 25 cm2 Pure‐Water‐Fed Non‐Precious Metal Anion Exchange Membrane Electrolyzer Cell

AbstractAnion exchange membrane (AEM) water electrolysis has emerged as a promising technology for producing hydrogen in a carbon‐neutral economy. To advance its industrial application, performance evaluations of non‐precious metal AEM electrolyzers with electrode areas of 25 cm2 were conducted. The focus was on pure water operation, achieving a current density of 0.26 A cm−2 at a voltage of 2.2 V. To gain a better understanding, the AEM electrolyzer was also operated in aqueous KOH, yielding 1.2 A cm−2 at 2.2 V. By adding a liquid electrolyte and by varying cell components, causes of the occurring performance limitations and ways to improve the AEM electrolyzer were identified. Electrochemical impedance analysis showed that the activation loss at the anode due to sluggish OER kinetics was the limiting factor at low current densities. At higher current densities, which is the operating range of interest for industrial application, the ohmic resistance from the membrane was the dominant factor limiting high performance in pure water operation.

Hole diffusion length and mobility of a long wavelength infrared InAs/InAsSb type-II superlattice nBn design

We demonstrated high-performance 8.9 μm cutoff wavelength nBn InAs/InAsSb type-II strained-layer superlattice (T2SL). These detectors exhibit a long minority carrier (hole) lifetime of 1.2 μs at 80 K, high quantum efficiency of 40% for back-side illuminated devices without antireflection coating, and low dark current density of 4.6 × 10−6 A/cm2 at 80 K. We measured absorption, minority carrier (hole) lifetime, quantum efficiency, and spectral response as a function of the temperature and applied bias. We investigated the temperature dependence of the hole diffusion length and mobility and found that their values increase with temperature from 1.3 μm and 6.5 cm2/Vs at 30 K to 6.5 μm and 36 cm2/Vs at T = 90 K. We compared the measured diffusion length and mobility of holes in long-wavelength infrared (LWIR) T2SL with these parameters of a high-performance mid-wavelength infrared (MWIR) T2SL. Unexpectedly, hole mobility in LWIR T2SL was found to be higher than in MWIR that is contrary to the theoretical predictions.

Mapping cellular coverage suitability: a GIS-Based approach to identifying poor service areas

Cellular coverage is a critical component of modern telecommunications, providing essential services for communication, commerce, and emergency response. Despite its importance, many regions, particularly those with challenging terrain or low population density, experience inadequate cellular service. This study focuses on the commune of Laghouat, Algeria, employing a GIS-based Multi-Criteria Analysis (MCA) to assess cellular coverage suitability. Using ArcGIS Pro, four key factors were integrated: cell tower locations, terrain elevation, population distribution, and restricted areas. The methodology includes performing a Viewshed analysis to identify dead zones, converting population data into raster format to map demand, and digitizing restricted areas where telecommunication infrastructure development is prohibited. All factors were standardized to a common scale to ensure comparability and a weighted overlay analysis was conducted to generate a comprehensive suitability map. The map highlights areas of poor cellular coverage, guiding the placement of new infrastructure. Additionally, the research considers regulatory restrictions on land use, ensuring compliance with governmental policies. The resulting suitability map provides valuable insights for telecommunications providers and policymakers, enabling them to target underserved regions for infrastructure improvements while adhering to legal constraints. This study offers a robust, scalable framework for identifying and addressing cellular coverage gaps, applicable to other regions with similar geographic and demographic challenges.