Macroscopic Description Research Articles

Crowd Density Estimation via Global Crowd Collectiveness Metric

Drone-captured crowd videos have become increasingly prevalent in various applications in recent years, including crowd density estimation via measuring crowd collectiveness. Traditional methods often measure local differences in motion directions among individuals and scarcely handle the challenge brought by the changing illumination of scenarios. They are limited in their generalization. The crowd density estimation needs both macroscopic and microscopic descriptions of collective motion. In this study, we introduce a Global Measuring Crowd Collectiveness (GMCC) metric that incorporates intra-crowd and inter-crowd collectiveness to assess the collective crowd motion. An energy spread process is introduced to explore the related crucial factors. This process measures the intra-crowd collectiveness of individuals within a crowded cluster by incorporating the collectiveness of motion direction and the velocity magnitude derived from the optical flow field. The global metric is adopted to keep the illumination-invariance of optical flow for intra-crowd motion. Then, we measure the motion consistency among various clusters to generate inter-crowd collectiveness, which constitutes the GMCC metric together with intra-collectiveness. Finally, the proposed energy spread process of GMCC is used to merge the inter-crowd collectiveness to estimate the global distribution of dense crowds. Experimental results validate that GMCC significantly improves the performance and efficiency of measuring crowd collectiveness and crowd density estimation on various crowd datasets, demonstrating a wide range of applications for real-time monitoring in public crowd management.

Study on the pore structure and permeability evolution of tight sandstone under liquid nitrogen freezing‐thawing cycles based on NMR technology

To further raise the gas extraction efficiency of the tight sandstone, the liquid nitrogen (LN2) freezing-thawing cycles method can be employed to improve the permeability of the low-permeability reservoirs. Permeability is generally regarded as a macroscopic description of the pore structure and usually has functional relationship to pore structure properties. The permeability of the rock is closely related to the change of microscopic pore structure. The permeability of rock depends on how the subzero temperatures changed the microscopic pore structure of rock, but it has not yet been confirmed obviously. In this study, the nuclear magnetic resonance (NMR) technique was adopted to investigate the pore structure evolution law and permeability of the tight sandstone with different LN2 freezing-thawing cycles. The results demonstrate that the LN2 freezing-thawing cycles promotes pore development and micro-fracture connection, and enhances the pore connectivity. The proportion of meso-pores, macro-pores and micro-fractures in the sandstone samples increases significantly, which provides a channel for the sandstone gas flow and extraction. Total porosity and effective porosity of the samples present a trend of rapid increase as the number of LN2 freezing-thawing cycles increasing, while the residual porosity decreases as the number of LN2 freezing-thawing cycles increasing. Coates model, SDR model (mean T2 model) and PP model were used to calculate and evaluate the permeability of the samples subjected to different LN2 freezing-thawing cycles. Furthermore, PP model can provide a better permeability estimate than the classical Coates and SDR model.

Morphology of Larger Salivary Glands in Peccaries (Pecari tajacu Linnaeus, 1758).

This work aims to study the major salivary gland morphology of peccaries during their growth. The glands were analyzed using macroscopic description, light microscopy, electron microscopy, histochemistry, and immunohistochemistry. Topographically, the salivary glands resemble other animals, including domestic animals and pigs. During growth, the parotid enlarges and mandibular gland loses weight. Histologically, the parotid has serous production, and sublingual has mucous production, resembles most species, however, mandibular gland produces mucous, unlike other animals, including pigs, which produce seromucous secretion. Histochemically, parotid produces more acidic mucins than pigs and it undergoes maturation during development; mandibular, and especially the sublingual gland, produce more acidic and basic mucopolysaccharides than pigs. The results found with transmission and scanning electron microscopy techniques corroborate the histological and histochemistry findings. The major salivary glands were positive to different lecithins (Com-A, BSA-I-B4, WGA and PNA), which were also more positive than in pigs and sheep. We conclude that collared peccaries have a salivary secretion that facilitates the digestion of carbohydrates, and biometric characteristics and positivity to lecithins that facilitate adaptation to foods with antinutritional factors.

Macroscopic and histopathological description of gastric lesions in horse, donkey, and mule fetuses in the last trimester of gestation.

Limited information is available on gastric diseases in neonatal foals as compared with extensive studies in young, adult, and geriatric horses. Reports on fetuses are scarce. Assess at necropsy stomachs of horse, donkey and mule fetuses in the third trimester of gestation to characterize lesions present during intrauterine life. Forty-six fetal stomachs from both sexes (21 horses, 21 donkeys, and 4 mules) in the third trimester of gestation were collected from a processing plant immediately after slaughter. Measurements of longitudinal and transverse axes, weight and volume and gastric fluid pH were taken, and glandular and squamous mucosae were inspected. All findings of the gastric mucosa and measurements of the stomachs were presented descriptively. Groups were compared statistically, with significance level set at P < .05 for all evaluations. All gastric contents had pH >5.8, and mules had larger stomachs and higher weights compared with horses (P < .05). Macroscopic lesions were classified as hyperemic, punctate, and erosive. Histopathologically, lesions were consistent with a chronic inflammatory process. Our study provides evidence of macroscopic and histopathological lesions in the gastric mucosae of equid fetuses in the last trimester of gestation. Relevant information for perinatology and neonatology is provided regarding the prevalence and classification of preulcerous lesions in equids before birth.

Learning macroscopic equations of motion from dissipative particle dynamics simulations of fluids

Macroscopic descriptions of both natural and engineered materials usually include a number of phenomenological parameters that have to be estimated from experiments or large-scale microscopic simulations. When dealing with advanced complex materials, these descriptions are sometimes not a priori available or not even known. Using sparsity-promoting techniques one can extract macroscopic dynamic models directly from particle-based simulations. In this work, we showcase such an approach on a simple fluid and test its robustness. We introduce a novel measure for automatic macroscopic model selection that combines stability and accuracy of a model. Using this measure and employing only a few physics-based assumptions, we are able to infer both the mass continuity equation and an equation for the conservation of linear momentum. Moreover, the extracted phenomenological and non-phenomenological parameters agree well with their numerically measured values and the well-known semi-empirical estimates. The presented model selection framework can be applied to simulations or experimental data of more complex systems, described in general by a rich set of coupled nonlinear macroscopic equations.

Exploring the limits of the law of mass action in the mean field description of epidemics on Erdös-Rényi networks

The manner epidemics occurs in a social network depends on various elements, with two of the most influential being the relationships among individuals in the population and the mechanism of transmission. In this paper, we assume that the social network has a homogeneous random topology of Erdös-Rényi type. Regarding the contagion process, we assume that the probability of infection is proportional to the proportion of infected neighbours.We consider a constant population, whose individuals are the nodes of the social network, formed by two variable subpopulations: Susceptible and Infected (SI model). We simulate the epidemics on this random network and study whether the average dynamics can be described using a mean field approach in terms of Differential Equations, employing the law of mass action. We show that a macroscopic description could be applied for low average connectivity, adjusting the value of the contagion rate in a precise function. This dependence is illustrated by calculating the transient times for each connectivity.This study contributes valuable insights into the interplay between network connectivity, contagion dynamics, and the applicability of mean-field approximations. The delineation of critical thresholds and the distinctive behaviour at lower connectivity enable a deeper understanding of epidemic dynamics.

Homogenization of high-contrast media in finite-strain elastoplasticity

This work is devoted to the analysis of the interplay between internal variables and high-contrast microstructure in inelastic solids. As a concrete case-study, by means of variational techniques, we derive a macroscopic description for an elastoplastic medium. Specifically, we consider a composite obtained by filling the voids of a periodically perforated stiff matrix by soft inclusions. We study the Γ-convergence of the related energy functionals as the periodicity tends to zero, the main challenge being posed by the lack of coercivity brought about by the degeneracy of the material properties in the soft part. We prove that the Γ-limit, which we compute with respect to a suitable notion of convergence, is the sum of the contributions resulting from each of the two components separately. Eventually, convergence of the energy minimizing configurations is obtained.

(Digital Presentation) Multiscale Modeling of Two-Phase Transport in the Membrane Electrode Assembly of Polymer Electrolyte Membrane Fuel Cells: Effect of Relative Humidity and Temperature

Water management plays an important role in the performance and durability of polymer electrolyte membrane fuel cells (PEMFCs). Achieving enhanced water removal at high current density without membrane dehydration requires an optimal design of the membrane electrode assembly (MEA) and MEA-channel interaction depending on operating conditions. The analysis of two-phase transport is challenged by the wide range of pore sizes found in porous layer assemblies, varying from 1-100 nm in the catalyst layer (CL), 50-1000 nm in the microporous layer (MPL) and 10 µm in the gas diffusion layer (GDL), up to the millimeter-sized channel. In this work, a hybrid multiscale model is presented to describe two-phase transport and performance of a representative unit cell as a function of relative humidity (RH) and temperature [1-3]. A control volume (CV) decomposition is used to represent the multiscale pore space of the GDL, MPL and CL in terms of local effective transport properties (porosity, effective diffusivity, permeability, thermal/electrical conductivity and entry capillary pressure) [4]. The model incorporates a macroscopic continuum formulation for gas flow and species, energy, liquid-phase pressure, water dissolved in ionomer, and electronic and ionic potentials [5]. Liquid water transport is modeled by means of a multi-cluster invasion-percolation algorithm, which is coupled to the macroscopic continuum formulation by the phase-change source term of water (evaporation/condensation). Water clusters with a net condensation rate grow by invading the adjacent dry CV with the lowest entry capillary pressure, while clusters with a net evaporation rate shrink by drying the wet CV of the cluster with the lowest entry capillary pressure. An all-or-nothing invasion law is adopted for saturation in the GDL (one pore per CV), while a macroscopic description in terms of capillary pressure curve at the representative elementary volume scale (REV) is used for the MPL and the GDL (thousands to millions of pores per CV). An example of the saturation distribution in the cathode MEA is shown in Figure 1. Local saturation remains between 0.1-0.4 in REVs of the CL and the MPL, increasing up to 1 in macropores of the GDL. Water condenses preferentially under the ribs and transport by capillary action to the GDL/channel interface, where the water flow is released to the channel. The channel saturation remains low, around 0.1, due to the large gas flow velocity used in the differential cell.[1] P.A. García-Salaberri, Modeling diffusion and convection in thin porous transport layers using a composite continuum-network model: Application to gas diffusion layers in polymer electrolyte fuel cells, 167 (2021) 120824.[2] D. Zapardiel, P.A. García-Salaberri, Modeling the interplay between water capillary transport and species diffusion in gas diffusion layers of proton exchange fuel cells using a hybrid computational fluid dynamics formulation, J. Power Sources 520 (2022) 230735.[3] P.A. García-Salaberri, Effect of thickness and outlet area fraction of macroporous gas diffusion layers on oxygen transport resistance in water injection simulations, Transp. Porous Media 145 (2022) 413-440.[4] P.A. García-Salaberri, I.V. Zenyuk, A General-Purpose Tool for Modeling Multifunctional Thin Porous Media (POREnet): From Pore Network To Effective Property Tensors, Heliyon (2023), submitted.[5] P.A. García-Salaberri, A. Sánchez-Ramos, A numerical analysis of the effect of layer-scale and microscopic parameters of membrane electrode assembly in proton exchange fuel cells under two-phase conditions, J. Power Sources (2023), accepted. Figure 1. Saturation distribution in the cathode MEA of a PEMFC operated at 70 oC and RH=0.95 at high stoichiometric conditions. The current density is I=0.5 A cm-2.- Figure 1

Achieving Optical Refractive Index of 10-Plus by Colloidal Self-Assembly.

This study demonstrates the developments of self-assembled optical metasurfaces to overcome inherent limitations in polarization density (P) and high refractive indices (n) within naturally occurring materials. The Maxwellian macroscopic description establishes a link between P and n, revealing a static limit in natural materials, restricting n to ≈4.0 at optical frequencies. Previously, it is accepted that self-assembly enables the creation of nanogaps between metallic nanoparticles (NPs), boosting capacitive enhancement of P and resultant exceptionally high n at optical frequencies. The work focuses on assembling gold (Au) NPs into a closely packed monolayer by rationally designing the polymeric ligand to balance attractive and repulsive forces, in that polymeric brush-mediated self-assembly of the close-packed Au NP monolayer is robustly achieved over a large-area. The resulting monolayer of Au nanospheres (NSs), nanooctahedras (NOs), and nanocubes (NCs) exhibits high macroscopic integrity and crystallinity, sufficiently enough for pushing n to record-high regimes. The systematic comparisons between each differently shaped Au NP monolayers elucidate the significance of capacitive coupling in achieving an unnaturally high n. The achieved n of 10.12 at optical frequencies stands as a benchmark, highlighting the potential of polyhedral Au NPs in advancing optical metasurfaces.

Basal Force Fluctuations and Granular Rheology: Linking Macroscopic Descriptions of Granular Flows to Bed Forces With Implications for Monitoring Signals

AbstractGranular flows are ubiquitous in nature with single flows traversing a wide range of dynamic conditions from initiation to deposition. Many of these flows are responsible for significant hazards and can generate remotely detectable seismic signals. These signals provide a potential for real‐time flow measurements from a safe distance. To fully realize the benefit of seismic measurements, basal‐granular forces must be linked to macroscopic internal flow dynamics across a wide range of flow conditions. We utilize discrete element simulations to observe dry and submerged granular flows under plane‐shear and inclined‐flow configurations, relating bulk kinematics to basal‐force distributions. We find that the power and frequency of force fluctuations scale with non‐dimensional shear rate (I). This scaling tracks three pre‐established regimes that are described by μ(I) rheology: (a) an intermittent particle rearrangement regime, where basal forces are dominated by low frequencies; (b) an intermediate regime where basal forces start to increase in frequency while showing correlations in space and (c) a fully collisional regime where the signal is nearly flat up to a cutoff frequency. We further identify a newly defined fourth regime that marks a “phase change” from the intermediate to collisional regime where increases in basal force fluctuations with increasing shear rates stalls as the granular bed dilates, partially destroying the contact network. This effort suggests that basal forces can be used to interpret complex granular processes in geophysical flows.

Time-dependent invasion laws for a liquid–liquid displacement system

Capillary-driven flow of fluids occurs frequently in nature and has a wide range of technological applications in the fields of industry, agriculture, medicine, biotechnology, and microfluidics. By using the Onsager variational principle, we propose a model to systematically study the capillary imbibition into a tube and find different laws of time-dependent capillary invasion length for liquid–liquid displacement system other than Lucas–Washburn type under different circumstances. The good agreement between our model and experimental results shows that the imbibition dynamics in a capillary tube with a prefilled liquid slug can be well captured by the dynamic equation derived in this paper. Our results bear important implications for macroscopic descriptions of multiphase flows in microfluidic systems and porous media.

Examining Invasion‐Percolation Across the Cathode Layered Assembly in Polymer Electrolyte Membrane Fuel Cells: Oxygen Resistance, Wettability and Cracks

AbstractEfficient evacuation of water generated by oxygen reduction reaction is necessary to increase catalyst utilization in polymer electrolyte membrane Fuel Cells. However, analysis of two‐phase transport is challenged by the wide range of pore sizes present in the membrane electrode assembly (MEA), varying from 10–100 nm in the catalyst layer (CL), 10–1000 nm in the microporous layer (MPL) and 10 μm in the gas diffusion layer (GDL). In this work, a novel multiscale invasion‐percolation model accounting for the cathode CL, MPL and GDL is presented. Saturation in the macroporous GDL is modeled through an all‐or‐nothing invasion law (empty/filled), while a macroscopic description in terms of the capillary pressure curve is adopted for the MPL and the CL. The oxygen transport resistance across the cathode MEA is quantified using the computed saturation distributions. Among other conclusions, the results show that MPL addition is crucial to avoid local flooding at the CL/GDL interface, providing localized access points to the GDL rather than massively invading interfacial macropores. However, excessive MPL hydrophobicity can cause CL flooding. Water removal from the CL can be enhanced by using a more hydrophilic MPL, a hydrophobic CL or the addition of a moderate volume fraction of cracks. Oxygen transport can be further improved by modulating the arrangement of water in the GDL with patterned wettability, provided that the number of MPL cracks is low.

Secondary secretory otitis media (SSOM) in 3 cats and 2 dogs.

To describe secondary secretory otitis media (SSOM) due to obstruction of the nasopharyngeal opening of the auditory tube in cats and dogs and to characterize the effusion by macroscopic description, microscopic cytology and bacteriological analysis. Three cats and 2 dogs with middle ear effusion and obstruction of the nasopharyngeal opening of the auditory tube detected on CT scans received myringotomy followed by macroscopic description, microscopic cytology and bacteriological analysis of the fluid obtained. All animals had serous to mucoid middle ear effusions and, in 2 cases, large numbers of inflammatory cells and secondary infection. Causes of auditory tube dysfunction ranged from iatrogenic stents (2) to neoplasia (3). In the non-neoplastic cases, effusion resolved in all cases after removal of the underlying cause. Obstruction of the nasopharyngeal opening of the auditory tube leads to accumulation of fluid within the middle ear in cats and dogs. If the cause of obstruction can be removed, fluid accumulation resolves. Fluid characteristics are comparable to middle ear effusions in pugs and French bulldogs. It is important to always examine the nasopharynx in cases of middle ear effusion to rule out SSOM.

Graph-enhanced deep material network: multiscale materials modeling with microstructural informatics

AbstractThis study addresses the fundamental challenge of extending the deep material network (DMN) to accommodate multiple microstructures. DMN has gained significant attention due to its ability to be used for fast and accurate nonlinear multiscale modeling while being only trained on linear elastic data. Due to its limitation to a single microstructure, various works sought to generalize it based on the macroscopic description of microstructures. In this work, we utilize a mechanistic machine learning approach grounded instead in microstructural informatics, which can potentially be used for any family of microstructures. This is achieved by learning from the graph representation of microstructures through graph neural networks. Such an approach is a first in works related to DMN. We propose a mixed graph neural network (GNN)-DMN model that can single-handedly treat multiple microstructures and derive their DMN representations. Two examples are designed to demonstrate the validity and reliability of the approach, even when it comes to the prediction of nonlinear responses for microstructures unseen during training. Furthermore, the model trained on microstructures with complex topology accurately makes inferences on microstructures created under different and simpler assumptions. Our work opens the door for the possibility of unifying the multiscale modeling of many families of microstructures under a single model, as well as new possibilities in material design.

Dark pottery from the early Iron Age in southern Veneto, Italy: The provenance issue under the adoption of specific technological procedures

One of the earliest known settlements of Pre-Roman Padua, Veneto Region (north-eastern Italy) was located in the very centre of the present-day city. The archaeological excavations revealed structures related to craft activities (metallurgical and pottery workshops) and residential areas datable from the late 9th to the 1st century BCE. A large pyrotechnic structure formed by an earthen block densely filled and covered by broken ceramic vessels was found, bringing to light the earliest foundry of the Pre-Roman Padua known to date. Many potsherds found in the site correspond to a regional ceramic class that included coarse and fine wares mainly composed of very dark ceramic bodies. A multi-analytical study based on macroscopic and petrographic descriptions as well as mineralogical, geochemical and microstructural analyses, was carried out in order to state the technological choices adopted for producing these dark vessels and the provenance of the raw materials. A poorly manufacturing was adopted to produce the common pottery, resulting coarse wares uneven textured, while the fine wares were produced by adopting the purification of the base clays and/or the tempering of the clay pastes. Common geo-resources were used, consisting in illitic-chloritic clays rich in quartz and feldspars, the firing regime conditions covered a range of maximum temperatures (normally under 850 °C) and the temper was constituted by silicate (chiefly quartzite, rhyolite and trachyte rock fragments) and/or carbonate (calcite and/or dolomite) inclusions, that were added after having been grounded and/or sieved. The specific mineral and lithic markers of provenance identified in the sherds confirmed the correspondence of this pottery with a local production. However, the specific technological choices that were carried out must be taking into consideration, since the purification removed the larger grains originally present in the base clays and the tempering influenced the chemical composition of the sherds. The different degree of purification of the base clays and the differential tempering procedures that were accomplished point out the adoption of very specific recipes to produce the fine wares, suggesting the correspondence of this local ceramic class with diverse sub-productions and the high level of specialization achieved by the potters in southern Veneto during the Early Iron Age.

Additions to Crepidotus species (Basidiomycota): Six new species and two new records from Thailand

Six new species and two new records of Crepidotus are described from Thailand. Macroscopic and microscopic descriptions with photoplates, as well as a multigene phylogeny, are provided. Crepidotus chiangraiensis sp. nov. is recognized as densely velutinous with white hairs longer near the point of attachment, not striate margin, and not hygrophanous. Crepidotus- flavocarpus sp. nov. is recognized by yellow to yellowish pileus basidiomata, margin discolorous paler yellow, densely velutinous with white hairs near the point of attachment, smooth globose basidiospores, and inverse hymenophoral trama. Crepidotus thailandicus sp. nov. is recognized by a tomentose surface with white hair when primordial to early stages and then disappearing with age when mature present long translucent-striate reward to the point of attachment becoming fade away at central. Crepidotus roseocarpus sp. nov. is recognized by large basidiomata, pileus, lamellae, and context are pastel pink, concolorous darker pink at the margin, hymenophoral trama convergent, with cylindrical terminal elements. Crepidotus-ungulatus sp. nov. is recognized by ungulate basidiomata, brownish orange near the point of attachment, the basidiomata color changed to light brown in three hours, and the margin is concolorous to the surface of the pileus. Crepidotus viscidus sp. nov. is recognized by white semicircular pileus, translucent-striate with gray to dark grey margin, lamellae pale orange to orange-white, glutinous context, smooth basidiospore and hymenophoral trama present regular form. Crepidotus lateralipes and C. striatus are reported as new records to Thailand.

Localization patterns emerging in CPTu tests in a saturated natural clay soil

In this work, the mechanics of cone penetration during CPTu tests in Osaka clay, a natural structured silty clay, was investigated with the Particle Finite Element Method (PFEM). To describe the behavior of the soil, the FD_MILAN model, recently proposed by the Authors, was adopted. The model, based on the multiplicative decomposition of the deformation gradient, incorporates a scalar internal variable, the bond strength Pt, to quantify the effects of structure. The macroscopic description of mechanical destructuration effects is provided by the hardening law of Pt, according to which the bond strength decreases monotonically with accumulated plastic deformations. The brittle behavior resulting from the softening process associated to destructuration make the soil quite susceptible to the spontaneous development of strain localization in the form of shear bands. In order to deal with strain localization phenomena, the model is equipped with a non-local version of the hardening laws, incorporating a material constant – the characteristic length ℓc – which provides the material with an internal length scale. The objective of this work was to get some insight on the effects of the characteristic length and of the initial degree of structure on: the kinematics of the soil deformation around the advancing cone tip; the evolution of soil structure with accumulated plastic deformations; the excess pore pressure field generated in the soil as a result of the hydro-mechanical coupling between the solid skeleton and the pore water, and the net cone resistance measured at the base of the cone. The results of the PFEM simulations show that the deformations around the piezocone are strongly affected by the characteristic length. For heavily structured soils, when ℓc is relatively small with respect to cone radius, the accumulated plastic deviatoric deformation field is characterized by clearly visible shear bands while, as ℓc increases, the detection of localized deformation regions becomes more difficult, if not impossible. This depends on the fact that, for large values of ℓc, the shear band width may be of comparable size to the cone radius. In all cases, the soil around the advancing piezocone is subjected to a very strong destructuration process, which leads to the complete loss of bond strength in a large region around the cone tip and shaft. As a consequence, the use of conventional Nc values from the literature in the interpretation of the CPTu test performed in heavily structured soils could provide undrained strength values closer to the ultimate undrained shear strength. At the same time, the use of empirical correlation to estimate the yield stress in oedometric conditions would lead to a significant underestimation of the overconsolidation ratio.

Does morphological maturity anticipate physiological maturity? The pattern of sexual maturity in males of the seabob shrimp Xiphopenaeus kroyeri (Heller, 1862)

The seabob shrimp Xiphopenaeus kroyeri (Heller, 1862) is an important fishing resource and is intensely exploited in South America. Therefore, for the correct and sustainable use of this fishing resource, it is necessary to employ multiple tools to determine the sexual maturity of this species, a key condition for the maintenance of this important economic resource. In this work, we evaluated the morphological (development of secondary sexual characteristics) and physiological (maturation of the reproductive system) sexual maturities in males of X. kroyeri, through the macroscopic and microscopic description of the testes, vasa deferentia and petasma from the juvenile stage to the adult stage. The male reproductive system of seabob shrimp is a paired organ with testes connected to a vasa deferentia, which is anatomically differentiated into three regions: proximal (PVD) (subdivided into anterior, or PVDa, and posterior, or PVDp), medial (MVD) and distal (DVD), the latter region being associated with the terminal ampulla. The morphological maturity of males preceded physiological maturity, meaning the petasma must be formed for the production of seminal fluid and the formation of spermatozoa contained in spermatophores to occur. Petasma formation occurred in the size class 12 ┤13 mm CL, while the production of spermatozoa and spermatophores occurred from 14.1 mm CL. These spermatophores are completely formed in the PVDp and are glycoproteic. Spermatophores are stored in the simple tube of the MVD and DVD. In the DVD, there is an accessory gland forming the ampulla, which produces part of the seminal fluid. The deposition of spermatophores occurs internally in the female’s thelycum with the aid of the petasma, which deposits the seminal fluid in the seminal receptacles or spermathecae. At the end of this process, the thelycum is sealed by a secretion from the accessory gland in the male’s ampulla, forming a sperm plug. Based on the results obtained here, we recommend that only physiologically mature males of X. kroyeri (> 14.1 mm CL) should be exploited by artisanal fisheries and that macroscopic inspection of the ampulla to determine physiological maturity in this species should be avoided, as this region of the DVD has the accessory gland as its main part, a structure responsible for forming the sperm plug, which does not contain spermatozoa or participate in the formation of spermatophores.

A Comprehensive Study of Meningioma Biomineralization: Morphological, Crystallographic, and Immunohistochemical Aspects.

Biomineralization of brain tissues occurs both in normal and pathological conditions. Dura mater biomineralization is widespread and occurs in 1-72% of cases, depending on the patient's age and research method. The amount of biomineral deposits under the conditions of tumor growth in the meninges only increases, reaching 100% in the case of psammomatous meningiomas. Since calcifications are often found in the meninges, the problem of differential diagnosis with calcified meningiomas arises. A total of 30 samples of meningiomas with signs of biomineralization-dense structure, characteristic crunch, psammoma bodies (group I) and 30 samples of meningiomas without any signs of biomineralization were examined as controls (group II). To detect pathological biomineralization, the meningioma tissue was studied using the methods of macroscopic description, histology, histochemistry, and immunohistochemistry, scanning electron microscopy with microanalysis, and transmission electron microscopy. A significantly higher level of caspase3 and features of the expression of osteoblastic markers (a lower level of OPG expression and a higher level of the presence of RANKL in group I, the absence of fluctuations in the expression of SPARC) may indicate a dystrophic type of development of biomineral deposits in meningiomas.

Macroscopic modeling of social crowds

Social behavior in crowds, such as herding or increased interpersonal spacing, is driven by the psychological states of pedestrians. Current macroscopic crowd models assume that these are static, limiting the ability of models to capture the complex interplay between evolving psychology and collective crowd dynamics that defines a “social crowd”. This paper introduces a novel approach by explicitly incorporating an “activity” variable into the modeling framework, which represents the evolving psychological states of pedestrians and is linked to crowd dynamics. To demonstrate the role of activity, we model pedestrian egress when this variable captures stress and awareness of contagion. In addition, to highlight the importance of dynamic changes in activity, we examine a scenario in which an unexpected incident necessitates alternative exits. These case studies demonstrate that activity plays a pivotal role in shaping crowd behavior. The proposed modeling approach thus opens avenues for more realistic macroscopic crowd descriptions with practical implications for crowd management.