Mesh Size Research Articles

Algorithms and data structures for Cs-smooth RMB-splines of degree 2s + 1

The simple mesh refinement algorithm of Groiss et al. (2023) generates T-meshes admitting Reachable Minimally supported (RM) B-splines that possess the property of local linear independence and form a non-negative partition of unity. The construction was first presented for the bilinear case and has later been extended to Cs-smooth splines of degree p=2s+1. The present paper is devoted to algorithms and data structures for RMB-splines. We prove that the memory consumption of the data structures for representing a T-mesh and the associated RMB-splines is linear with respect to the mesh size, and we describe the details of the underlying refinement algorithm. Moreover, we introduce a novel evaluation algorithm for RMB-spline surfaces, which is based solely on repeated convex combinations of the control points, thereby generalizing de Boor's algorithm for tensor-product splines. Numerical experiments are included to demonstrate the advantageous behavior of the proposed data structures and algorithms with respect to their efficiency. We observe that the total computational time (which includes also error estimation and spline coefficient computation) scales roughly linearly with the number of degrees of freedom for the meshes considered.

Contrasting responses to aridity by different-sized decomposers cause similar decomposition rates across a precipitation gradient.

Litter decomposition is expected to be positively associated with precipitation despite evidence that decomposers of varying sizes have different moisture dependencies. We hypothesized that higher tolerance of macro-decomposers to aridity may counterbalance the effect of smaller decomposers, leading to similar decomposition rates across climatic gradients. We tested this hypothesis by placing plant litter baskets of different mesh sizes in seven sites along a sharp precipitation gradient, and by characterizing the macro-decomposer assemblages using pitfall trapping. We found that decomposers responded differently to precipitation levels based on their size. Microbial decomposition increased with precipitation in the winter while macro-decomposition peaked in arid sites during the summer. This led to similar overall decomposition rates across the gradient except in hyper-arid sites. Macro-decomposer richness, abundance, and biomass peaked in arid environments. Our findings highlight the importance of macro-decomposition in arid-lands, possibly resolving the dryland decomposition conundrum, and emphasizing the need to contemplate decomposer size when investigating zoogeochemical processes.

Contrasting responses to aridity by different-sized decomposers cause similar decomposition rates across a precipitation gradient

Litter decomposition is expected to be positively associated with precipitation despite evidence that decomposers of varying sizes have different moisture dependencies. We hypothesized that higher tolerance of macro-decomposers to aridity may counterbalance the effect of smaller decomposers, leading to similar decomposition rates across climatic gradients. We tested this hypothesis by placing plant litter baskets of different mesh sizes in seven sites along a sharp precipitation gradient, and by characterizing the macro-decomposer assemblages using pitfall trapping. We found that decomposers responded differently to precipitation levels based on their size. Microbial decomposition increased with precipitation in the winter while macro-decomposition peaked in arid sites during the summer. This led to similar overall decomposition rates across the gradient except in hyper-arid sites. Macro-decomposer richness, abundance, and biomass peaked in arid environments. Our findings highlight the importance of macro-decomposition in arid-lands, possibly resolving the dryland decomposition conundrum, and emphasizing the need to contemplate decomposer size when investigating zoogeochemical processes.

Chironomid Pupal Exuviae Technique in Ecological Research of Man-Made Water Bodies

Reservoirs serve functional purposes such as irrigation and power generation. However, concerns are raised due to the alterations of the connected riverine ecosystems. Chironomidae (Diptera), a diverse aquatic macroinvertebrate group, are vital to the functioning of ecosystems and serve as water quality indicators. Their holometabolous development includes the pupal stage after four larval stages. The chironomid pupal skin (exuvia) is used in environmental assessments, where the Chironomid Pupal Exuvial Technique (CPET) is a recognized standard. The CPET method is adaptable to different freshwater environments and here was applied in the study of 28 man-made lakes in the Pannonian Lowlands and Dinaric Western Balkan Ecoregion in Croatia to obtain information on chironomid diversity and analyze the potential influence of environmental factors on the chironomid community. The lake surface was skimmed with an exuvial hand net (mesh size of 300 µm) along the lake edge with a transect length of 10 m in the area of accumulated debris of organic and inorganic matter. Individual exuviae were mounted in a Berlese mounting medium and identified by morphological characteristics to the lowest taxonomic level. During the study, 5698 chironomid pupal skins were collected, and 141 taxa (including 97 species) belonging to five subfamilies were identified. The tribe Tanytarsini comprised 40% of the identified taxa, with Paratanytarsus spp. being the most abundant. In the Dinaric ecoregion, Paratanytarsus bituberculatus dominated, while Microchironomus tener and the genus Cricotopus were the dominant taxa in the Pannonian ecoregion. Community structure in the Pannonian ecoregion was influenced by total organic carbon (TOC) and orthophosphates (PO43−), indicating higher anthropogenic pressure compared to the Dinaric ecoregion, where water conductivity influenced Chironomidae assemblages. The research has provided valuable and useful information on the chironomid diversity in man-made and highly altered water bodies, as some of the most vulnerable aquatic habitats to anthropogenic influence. The CPET method could be a useful tool for the ecological studies and bioassessment of water quality in Croatia.

Testing best practices in small scale fisheries management: Evidence from a collaborative intervention in two marine protected areas of the central Mediterranean Sea

Adopting best practices (BPs) in small scale fisheries (SSF) is generally acknowledged to enhance ecological and social conditions, improving SSF management overall. Yet studies that empirically assess the effects of BPs on social-ecological outcomes (e.g., fishers' catches, revenues, and level of support towards management measures) remain limited. This study aimed to assess the effects of adopting BPs on catch per unit of effort (CPUE), revenue per unit of effort (RPUE) and small-scale fishers' perceptions in two Marine Protected Areas (MPAs) in Campania, Italy (Santa Maria di Castellabate (CAS-MPA) and Regno di Nettuno (NET-MPA)). Two BPs were implemented and tested in the two MPAs: i) five selective gears with three different mesh/hook sizes and ii) a participatory approach to increase dialogue between fishers and managers. The results from 36 surveys with small scale fishers and 158 SSF operations monitored using photo-sampling and image analysis techniques (between 2020 and 2022) are presented. Analyses of landings showed that significant differences in CPUE and RPUE between mesh/hook sizes were found in a limited number of cases (i.e., combination of fishing gears used in the 2 MPAs). Significant but divergent effects were found on CPUE in the two MPAs for gillnet used to target amberjack (GNA) only. RPUE was significantly higher in the NET-MPA when adopting the largest mesh size for GNA and the largest hook size for bottom longlines (BLL). When analyzing perceptions, fishers generally reported that the BPs adopted had a positive impact on their revenues, improved their relationship with MPA managers and increased their support for the MPA. In addition, eight stakeholder focus groups were held which helped investigators better understand the context, feedback the data gathered from the research and open up dialogue between the relevant stakeholders. The study concluded that increasing mesh/hook sizes, within the range tested here, does not negatively impact fishers’ revenues, while likely improving the status of target populations. Moreover, increasing dialogue between fishers and decision-makers can generate more positive perceptions towards the MPA and improve mutual understanding, helping to reconcile biodiversity conservation with human wellbeing for SSF.

Mesh Refinement for Dynamics Airflow in Health Care

This studyexplores using computational fluid dynamics(CFD) tooptimize ventilation in healthcare, with a focus on mesh refinement for accurate airflow analysis. The goal is to reduce airborne contaminant spread, which is crucial during COVID-19. Ventilation in healthcare ensures air quality and minimizes pathogen transmission. The research analyzer analyzes mesh element size's impact on airflow accuracy in simulated hospital wards with two coughing patients. The optimal mesh size is determined for reliable predictions. Mesh refinement enhances accuracy in critical zones. The k-epsilon turbulence model is chosen for low error. Experimental validation shows temperature discrepancies, likely due to simulated manikins lacking clothing insulation. Air velocity measurements show minor variations within an acceptable range. Further research on various ventilation configurations and airflow rates in real hospital conditions is crucial. Addressing these limitations optimizer optimizeshealthcare ventilation, enhancing safety and infection control.

Study on the adsorption process and kinetic, thermodynamic of bio-based waste cattle hair powder toward acidic complex dye.

In this paper, cattle hair waste (CHW) was collected and physically milled into different meshes of ultrafine cattle hair powder (UCHP). The reuse of CHW reaches the purpose of treating pollution with waste by using bio-base adsorbent. It was characterized by using scanning electron microscope-energy dispersive spectrometer (SEM-EDS), Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), differential scanning calorimeter (DSC), and X-ray diffraction (XRD). The adsorption studies were carried out under different conditions of temperature, time, pH, concentration of dye solution, mesh size, and dosage of cattle hair powder, respectively. The pseudo-first and pseudo-secondary kinetics and intra-particle diffusion models were employed to analyze the adsorption kinetic. The Langmuir, Freundlich, and Temkin adsorption isotherm was used to analyze the adsorption isotherm. The results showed that the adsorption capacity of UCHP for acidic metal complex (Trupoxane Brown R6) dyes increased with the decreasing pH solution. The adsorption capacity of 200 mesh UCHP was 379.5mg.g-1 when the adsorption conditions were as follows: 100mL dye solution with the initial concentration of 1000mg·L-1, the dosage of adsorbent was 0.1g, the pH was 3 for 12h at 40°C. The kinetic model fitting results showed that the adsorption of dyes by UCHP conformed to the pseudo-second-order kinetic model. Adsorption thermodynamics study showed that the Langmuir model has the highest fitting result. The amino group contained on the surface of cattle hair powder and the amide bond contained in the molecular chain of peptide chain have better electrostatic adsorption binding force for acid metal complex dyes, and the binding between them is mainly electrostatic attraction. The experimental results show that the ultrafine powder has better adsorption property, which provides a high-value conversion way for recycling waste cattle hair.

Activity concentrations of 60 Co, 137Cs and 241Am in sieved soil and soil inclusions from the «Taiga» peaceful nuclear explosions site

The article presents results of comparative study of 137Cs, 60Co, and 241Am activity concentrations in components of the soil samples collected in 2009 on the territory adjacent to the «Taiga» peaceful nuclear explosions site (the Perm region, Russia). The objective of the study was to identify differences between: 1) non fractionated native soil, 2) the soil passed through a sieve with a mesh size of 1.2 mm, and 3) the screened out coarse components. Measurements of the radionuclides activities in counting samples were performed using a semiconductor gamma spectrometer. Statistically significantly lower activity concentrations of 137Cs (factor of 1.2), 60Co (factor of 2.2) and 241Am (factor of 2.6) were found in the finely dispersed sieved fraction of soil compared to the native soil. On the opposite, in the solid radioactive inclusions selected from the screened out coarse fraction, the activity concentrations of 137Cs, 60Co and 241Am were significantly higher compared to those in the native soil. Especially large differences (up to a factor of 10 and more) between the native soil and radioactive inclusions were observed for the refractory and low-volatile 60Co and 241Am. Presumably, these radionuclides were concentrated predominantly in the glassy substance of the radioactive inclusions. For 137Cs, the unevenness in the contamination of different soil components was less pronounced. The results obtained will be used to standardize methods for assessing radioactive contamination of the territory at the sites of peaceful nuclear explosions

Element behavior during autoclave oxidation of polymetallic sulfide flotation concentrate containing tungsten and molybdenum

In this paper, we investigate the behavior of associated elements (tungsten, molybdenum, and bismuth) contained in a sulfide gold-bearing concentrate during its autoclave oxidation. The process is studied using a sulfide flotation concentrate, crushed to a particle sieve mesh size of minus 0.045 mm and containing 22.1 g/t of gold, 133.2 g/t of silver, 2.7% of tungsten, 13% of molybdenum, and 0.7% of bismuth. The process was carried out in a 2 dm3 autoclave at a temperature of 220ºC and an oxygen partial pressure of 0.7 MPa. The concentrations of sulfuric acid and iron ions in the solution were determined by titrimetric analysis. Inductively coupled plasma atomic emission spectroscopy was used to determine the concentrations of bismuth, tungsten, molybdenum, copper, silver, and arsenic in the solution, as well as the content of bismuth, tungsten, molybdenum, copper, arsenic, lead, and iron and sulfur forms in the cake. The cake was also examined using diffraction analysis. Experiments on cyanidation of oxidized cake were carried out in the pH range of 10.0–10.5 and a NaCN concentration of 1 g/dm3 with a PuroliteS992 ion exchange resin for 24 h. Autoclave oxidation experiments showed the sulfide oxidation degree to be higher than 99%. Extraction of molybdenum into solution in the form of [MoO2(SO4)n]-(2n-2) and MoO 2+ amounted to 95%. The decrease in the solid mass led to an increase in the concentration of bismuth and tungsten in the cake, with their contents reaching 1.66% and 12.7%, respectively. The main phases in the cake were established to be scheelite, anhydrite, plumboyarosite, and bedantite. The extraction of precious metals at the subsequent cyanidation stage amounted to 97.5% of gold and 91.6% of silver. Therefore, autoclave cyanide processing of sulfide gold-containing concentrates leads to a molybdenum extraction in the autoclave oxidation solution at the level of 95%. During cyanidation, more than 90% of gold and silver are extracted. Due to the significant amount of tungsten (17%), bismuth (0.9%), lead (5.3%), and molybdenum (3.3%), the obtained cake cannot be considered a waste product.

Per-recruit analysis and proposed sustainable harvest strategy for rednose labeo Labeo rosae and Mosambique tilapia Oreochromis mossambicus in Flag Boshielo Dam, Olifants River, South Africa

Inland fisheries development in South Africa has been proposed to improve rural livelihoods and food security. However, inland fisheries are susceptible to collapse through overfishing. Therefore, establishing biological reference points for these fisheries is essential for long-term sustainability. Here, spawner-biomass-per-recruit (SBR) analysis was used to set biological reference points for a gillnet fishery targeting the rednose labeo Labeo rosae and Mozambique tilapia Oreochromis mossambicus at Flag Boshielo Dam on the Oliphants River in Limpopo Province, South Africa. Both species are currently exploited at the impoundment by subsistence fishers that keep their entire catch. The current yields are estimated at 59 and 172 g yr−1 for L. rosae and O. mossambicus, respectively. The per-recruit analysis showed that age-at-first-capture for both species should be 4 years, at minimum lengths of 280 mm TL and 250 mm TL for L. rosae and O. mossambicus, respectively, with fishers using a minimum mesh size of 100 mm to reduce the risk of stock collapse. To maintain a SBR value greater than 25% of a pristine population, the L. rosae yield could be increased to 98 g yr−1, while the O. mossambicus yield could be increased to 176 g yr−1, following implementation of the recommended mesh size and size limits. A per-recruit analysis for O. mossambicus that includes recruitment variability and error to accurately calculate the biological reference points is recommended.

Analysis of a Combined Spherical Harmonics and Discontinuous Galerkin Discretization for the Boltzmann Transport Equation

Abstract In [L. Bourhrara, A new numerical method for solving the Boltzmann transport equation using the PN method and the discontinuous finite elements on unstructured and curved meshes, J. Comput. Phys. 397 2019, Article ID 108801], a numerical scheme based on a combined spherical harmonics and discontinuous Galerkin finite element method for the resolution of the Boltzmann transport equation is proposed. One of its features is that a streamline weight is added to the test function to obtain the variational formulation. In the present paper, restricting our attention to the advective part of the Boltzmann equation, we prove the convergence and provide error estimates of this numerical scheme. To this end, the original variational formulation is restated in a broken functional space. The use of broken functional spaces enables to build a conforming approximation, that is the finite element space is a subspace of the broken functional space. The setting of a conforming approximation simplifies the numerical analysis, in particular the error estimates, for which a Céa’s type lemma and standard interpolation estimates are sufficient for our analysis. For our numerical scheme, based on ℙ k {\mathbb{P}^{k}} discontinuous Galerkin finite elements (in space) on a mesh of size h and a spherical harmonics approximation of order N (in the angular variable), the convergence rate is of order 𝒪 ⁢ ( N - t + h k ) {\mathcal{O}(N^{-t}+h^{k})} for a smooth solution which admits partial derivatives of order k + 1 {k+1} and t with respect to the spatial and angular variables, respectively. For k = 0 {k=0} (piecewise constant finite elements) we also obtain a convergence result of order 𝒪 ⁢ ( N - t + h 1 2 ) {\mathcal{O}(N^{-t}+h^{\frac{1}{2}})} . Numerical experiments in one, two and three dimensions are provided, showing a better convergence behavior for the L 2 {L^{2}} -norm, typically of one more order, 𝒪 ⁢ ( N - t + h k + 1 ) {\mathcal{O}(N^{-t}+h^{k+1})} .

A Mesh Convergence Study for 2D Axisymmetric Pipe Wall Thickness

A meshing size study is essential for any simulation, as it affects the accuracy of the results by approximating the real-world geometry. This paper presents a detailed mesh convergence study for a 2D axisymmetric pipe model. The model incorporates a one-quarter cross-section due to the axisymmetric nature of the pipe. Four pipe wall thicknesses were investigated: 3.40 mm, 7.11 mm, 10.97 mm, and 18.26 mm. The results revealed a significant advantage for simulations involving thin pipes. They achieved convergence, a state with stable solution values, by utilizing a less dense mesh, leading to reduced computational time. This trend was exemplified by the fact that a thinner pipe with thickness, t = 3.40 mm has converged with only 8 mesh elements, whereas a significantly thicker pipe, t = 18.26 mm necessitated 14 elements for convergence. This suggests that more complex geometries, with intricate details, may require a larger and denser mesh for convergence, leading to increased computational time. In conclusion, the mesh convergence study confirms that the finite element analysis (FEA) model has achieved a converged solution.

Controlled stiffness and diffusivity of poly(ethylene glycol) hydrogel formed with cellulose-nanofiber framework

Hydrogels composed of polymer networks are widely used in industry and scientific research for high water retention and unique mechanical properties. Nevertheless, in ordinary hydrogel formation, the trade-off relationship between stiffness and mesh size remains a crucial consideration for practical applications. This study describes a facile approach to controlling hydrogel stiffness and mesh size by hybridizing poly(ethylene glycol) diacrylate (PEGDA) and methacrylated TEMPO-oxidized cellulose nanofibers (T-CNFMA). After disintegrating T-CNF by ultrasonication, T-CNFMA was synthesized resulting in a degree of substitution of 2.04 mmol/g. Incorporation of T-CNFMA in the PEGDA network allowed for independent control of hydrogel stiffness and mesh size by reinforcing the whole hydrogel network as a framework. Consequently, the swelling ratio and shear modulus could be manipulated by controlling the PEGDA/T-CNFMA ratio. Structural analyses revealed that an increase in the T-CNFMA content in the presence of a low amount of PEGDA resulted in a large mesh size with a constant stiffness. The diffusivity test was also consistent with the properties of the hydrogels. This result indicates that the incorporation of T-CNF in hydrogel network is useful to control the physical property of the hydrogel, especially for varying mesh size, regardless of stiffness alteration.

A distinctive material removal mechanism in the diamond grinding of (0001)-oriented single crystal gallium nitride and its implications in substrate manufacturing of brittle materials

Single crystal gallium nitride (GaN) substrates are highly demanded for fabricating advanced optoelectronic devices. It is thus essential to develop high efficiency machining technologies for this difficult-to-machine material, which in turn necessitates a thorough understanding of its deformation mechanism. In this study, the deformation and removal characteristics of (0001)-oriented single crystal GaN involved in diamond grinding were systematically investigated. The material removal exhibited a brittle mode when using relatively coarse diamond abrasives of 2000 in mesh size, while ductile removal was achieved when diamond abrasives of 6000 in mesh size were utilized. A novel peeling phenomenon was observed along (0001) lattice plane (c-plane) in the coarse grinding, as the crystal has a hexagonal crystal structure with c-planes serving as the preferable slip/cracking planes. Peeling observed in material removal agrees well with the findings that lateral planar defects were prone to initiate in nanoscratching in comparison to nanoindentation in the ductile regime, indicating that the effect of tangential grinding force is significant. The application of Molecular dynamics (MD) simulations, employing smaller indentation/scratching models, provided additional confirmation of the crucial role played by lateral force in initiating planar defects on c-planes. Furthermore, larger-scale MD scratching models substantiated the occurrence of peeling in the deformation process on c-plane, a finding corroborated by scratching experiments conducted in the brittle regime. Conversely, such peeling is absent on m- and a- planes. Complementary to the simulations, specifically designed grinding experiments were conducted to empirically demonstrate that peeling phenomena were intensified with elevated rotational wheel speeds. This enhancement was attributed to the increased tangential grinding force associated with higher speeds. These findings contribute to a comprehensive understanding of the intricate relationship between rotational wheel speed, tangential grinding force, and the observed peeling mechanisms in the context of single crystal GaN machining.

Optimization of abrasive slurry assisted rotating ultrasonic machining for enhanced micro-channel fabrication on ceramic silicon wafer (111)

This study examined the impact of abrasive slurry assisted Rotating Ultrasonic Machining (RUM) using Boron Carbide (B4C) powder of three mesh sizes: 400 Mesh, 600 Mesh, and 800 Mesh. The effects of abrasive size, feed rate, and tool rotation on Material Removal Rate (MRR) and Surface Roughness (SR) were investigated. The highest MRR of 3.454 mm³/min was achieved with 400 mesh, 30 mm/min feed rate, and 1250 rpm due to larger abrasive size, medium feed rate, and medium tool rotation velocity, while the lowest MRR of 0.284 mm³/min was noted with 600 mesh, 30 mm/min feed rate, and 1500 rpm, attributed to intermediate abrasive size and high tool rotation. The lowest SR of 1.16 μm was observed at 800 mesh, 15 mm/min feed rate, and 1500 rpm, resulting from smaller abrasive size and higher tool rotation facilitating polishing action and vibrational dampening. The highest SR of 3.71 μm occurred at 400 mesh, 45 mm/min feed rate, and 1500 rpm, due to larger abrasive size, higher feed rate, and tool rotation, increasing surface corrosion. ANOVA and regression analyses highlighted mesh size as the most significant parameter for both MRR and SR, with strong model-experimental value correlations. The findings demonstrate the suitability of abrasive slurry assisted RUM for fabricating micro-channels in X-Ray, optoelectronic, and semiconductor applications.

Uniform error analysis of an exponential IMEX-SAV method for the incompressible flows with large Reynolds number based on grad-div stabilization

Based on the grad-div stabilization and scalar auxiliary variable (SAV) methods, a first-order Euler implicit/explicit finite element scheme is studied for the Navier–Stokes equations with large Reynolds number. In the designing of numerical scheme, the nonlinear term is explicitly treated such that one only needs to solve a constant coefficient algebraic system at each time step. Meanwhile, the proposed scheme is unconditionally stable without any condition of the time step τ and mesh size h. In finite element discretization, we use the stable Taylor-Hood element for the approximation of the velocity and pressure. By a rigorous analysis, we derive an uniform L2 error estimate O(τ+h2) of the velocity in which the constant is independent of the viscosity coefficient. Finally, numerical experiments are given to support theoretical results and the efficiency of the proposed scheme.

Research on preparation and microscopic mechanism of heat-insulating & flame-retardant EP/PI composite aerogel

Polyimide aerogels, with their lightweight, thermal insulation, and flame-retardant properties, have found extensive applications in aerospace, military, and other fields. However, their use in the building insulation materials market is rare. This paper focuses on polyimide (PI) aerogels and incorporates expanded perlite (EP) of different mesh sizes and qualities to prepare expanded perlite/polyimide (EP/PI) aerogels, aiming to enhance the performance of building insulation materials and reduce energy consumption in buildings. The research results indicate that the incorporation of EP not only protects the aerogel framework from complete destruction and improves its high-temperature stability but also significantly affects the pore distribution of PI aerogels. Specifically, doping a mass of 0.2g of expanded perlite with a mesh size of 80 can increase the specific surface area of PI aerogels by 15 times, effectively increasing the number of pores and the quantity of non-communicating pores in the aerogel, while also reducing the thermal conductivity of PI aerogels by 10 %, thereby hindering heat transfer and enhancing their thermal insulation and flame-retardant properties. To gain a deeper understanding of the thermal insulation mechanism of aerogels, the study combines molecular dynamics principles to analyze the diffusion of nitrogen molecules within the aerogel, thereby elucidating the heat transfer process and explaining the thermal insulation mechanism of EP/PI aerogels. Overall, the findings of this study demonstrate low density, low thermal conductivity, good high-temperature stability, and excellent thermal insulation and flame-retardant effects, indicating significant application potential and socio-economic benefits in building insulation materials.

Study and Notes for the Freshwater Spercheidae, Dryopidae and Heteroceridae (Coleoptera) Fauna of Erzurum Province: A New Record for Türkiye

In this study, samples of Dryopidae, Heteroceridae and Spercheidae (Coleoptera) were collected from the shallow areas of lakes, ponds, rivers and small puddles in Erzurum province (Türkiye) between 2015 and 2020 with sieves of 3.15 x 1 mm pore size (mesh size 500 µm). A total of 4 different species were found. Two individuals from Dryops griseus (Erichson, 1847) species; 1 individual from the species Dryops jeanneli Bollow 1938; 2 individuals of Heterocerus fenestratus Thunberg 1784; and 2 individuals of Spercheus emarginatus (Schaller, 1783) species were caught. The collected samples were evaluated based on their morphological and ecological characteristics. While D. griseus was recorded for the first time in Türkiye, D. jeanneli and S. emarginatus are the third examples of species recorded in Türkiye. Additionally, these two species were recorded for the first time in the Eastern Anatolia region. H. fenestratus, collected from the Eastern Anatolia Region by another researcher, was also found during the study. The lateral parameters of the species' aedeagophores collapse from the middle towards the interior. Aedeagophore photographs and distribution data in the country and worldwide are discussed in the article. The average temperature and chemical parameters (electrical conductivity, pH, total nitrogen, dissolved oxygen, total phosphorus and water temperature) of the water bodies where the four different species were collected were found to be close to each other. To comprehend the life cycle, ecological data, along with morphological descriptions and vegetation information for each species are described.

The challenge of harvesting common sole (Solea solea) in highly selective trawl fisheries

Common sole (Solea solea) is an economically important species in several European trawl fisheries, yet little is known about the size selective properties of codends used in bottom trawl fisheries targeting sole. This study presents results from a sea trial conducted in the inner Danish waters where common sole is fished in a seasonal trawl fishery using a 90 mm diamond mesh codend with a mandatory large mesh escape panel. To improve understanding of the selectivity in this gear, we in addition tested a plain 90 mm diamond mesh codend without an escape panel. This combination of codend mesh size and large mesh escape panel is part of an ambitious management plan aimed at eliminating bycatch of cod (Gadus morhua) in trawl fisheries in the inner Danish waters. In the fishery for common sole, we found a severe mismatch between gear regulations and minimum conservation reference size of the target species. The outcome is a highly inefficient fishery in which only 22 % (CI: 18–27 %) by weight of the marketable sole is retained in the 90 mm diamond mesh codend. Further, we estimated that 25 % (CI: 16–35 %) of the sole entering the codend would contact the mandatory escape panel and escape, resulting in a total loss of 83 % (CI: 79–87 %) of marketable sole through the mandatory gear. The inefficiency in this fishery demonstrates the need for other means than gear specifications to regulate this type of fishery.

Does defect size matter in abdominal wall reconstruction with successful fascial closure?

BackgroundConflicting literature suggests that larger defects in abdominal wall reconstruction both increase the risk of recurrence and have no impact on recurrence. In our prior work, hernias with defect areas ≥100 cm2 were associated with increased discomfort, operative time, and length of stay but not recurrence or reoperation. Our goal was to determine if defect size, even in giant hernias, would impact recurrence after mesh repair with complete fascial closure. MethodsA prospectively maintained hernia database was reviewed for clean, abdominal wall reconstruction with fascial closure and synthetic mesh. Patients were grouped and compared by defect area: moderate hernias <200 cm2 (LT200) and giant hernias ≥200 cm2 (GT200). ResultsOf 984 patients, 607 LT200 (average area: 92.8 ± 60.8 cm2) were compared with 377 GT200 (average area: 363.2 ± 196.7 cm2). LT200 and GT200 had similar mean age, body mass index, and smoking rate, but GT200 had higher rates of diabetes (22.1% vs 27.9%; P = .040), recurrent hernias (52.7% vs 63.4%; P = .001), preoperative Botox (0.7% vs 8.8%; P < .001), component separation (23.4% vs 59.9%; P < .001), panniculectomy (8.7% vs 15.4%; P = .001), and negative-pressure incisional vacuum placement (5.9% vs 13.5%; P < .001). GT200 had increased mesh size (753.5 ± 367.1 vs 1168.2 ± 412.0 cm2; P < .001), operative time (147.8 ± 55.7 vs 205.3 ± 59.9 minutes; P < .001), and length of stay (5.1 ± 3.2 vs 6.9 ± 4.4 days; P < .001). GT200 had more wound complications (24.7% vs 36.1%; P < .001) and readmissions (9.1% vs 15.1%; P = .004) but similar recurrence rates (3.0% vs 3.7%; P = .520) over the mean follow-up of 30.1 ± 38.9 and 23.0 ± 33.6 months for LT200 and GT200, respectively. On multivariable regression, previous abdominal wall reconstruction, lightweight mesh, and wound complications independently predicted recurrence; component separation was protective, but defect size was not predictive of recurrence. ConclusionGT200 required more complex measures to achieve fascial closure and resulted in increased length of stay, wound complications, and readmissions; however, GT200 had the same recurrence rate as smaller defects when fascial closure was achieved.