Prolate Spheroidal Shape Research Articles

Ontogenic transformation of the ankle from the initial mediolateral arrangement of the calcaneus and talus: Ahistological study of human embryos and early fetuses.

The human calcaneus is robust and provides a prominent heel for effective bipedal locomotion, although the adjacent talus has no muscle attachments. However, there is incomplete information about the morphological changes in these prominent bones during embryo development. We examined serial histological sections of 23 human embryos and early-term fetuses (approximately 5-10 weeks' gestational age [GA]). At a GA of 5 weeks, the precartilage talus was parallel to and on the medial side of the calcaneus, which had a prolate spheroid shape and consisted of three masses. At a GA of 6 weeks, the cartilaginous talus extended along the proximodistal axis, and the tuber calcanei became long and bulky, with a small sustentaculum talus at the "distal" side. At a GA of 6 to 8 weeks, the sustentaculum had a medial extension below the talus so that the talus "rode over" the calcaneus. In contrast, the talus had a more complex shape, depending on the growth of adjacent bones. At a GA of 9 to 10 weeks, the talus was above the calcaneus, but the medial part still faced the plantar subcutaneous tissue because of the relatively small sustentaculum. Therefore, the final morphology appeared after an additional several weeks. Muscle activity seemed to facilitate growth of the tuber calcanei, but growth of the other parts of calcaneus, including the sustentaculum, seemed to depend on active proliferation at the different sites of cartilage. Multiple tendons and ligaments seemed to fix the talus so that it remained close to the calcaneus.

Pollen morphology of Asteraceae from Garhwal Himalaya (Uttarakhand, India): part I

Palynotaxonomy is crucial for understanding plant evolution, biodiversity, and ecological history by systematically classifying and identifying species based on pollen morphology. In addition, a regional pollen flora is crucial for precise pollen identification in various applied fields of palynology, including melissopalynology, aeropalynology, forensic palynology, paleopalynology, and copropalynology. In this communication, we explore the pollen morphology of 28 species of Asteraceae, employing both light (LM) and scanning electron microscopy (SEM). The results revealed that the grains were monad, isopolar, radially symmetric, tricolporate, and exhibited oblate-spheroidal to prolate-spheroidal shapes. The infratectum was found to be columellate, caveate, or noncaveate. The supratectum exhibited echinate or microechinate characteristics, with the exine surface showing perforate, microreticulate, or perforate regulate features. Among some species, a lophate pattern was observed, revealing two distinct variations: one characterized by a ‘15 lacunae type,’ while the other exhibited a ‘21 lacunae type’. Some unusual variations were observed in the aperture character among certain species, like the occurrence of tricolpate grains and pollen dimorphism due to variation in aperture number. Light microscopic examination was preliminary for resolving columellar structure but it clearly showed a double level of columella in some species. A cluster analysis, incorporating qualitative and quantitative features of pollen grains and an artificial pollen key have been set forth to distinguish studied species, supplemented by LM and SEM micrographs. The current findings have enriched the existing pollen database of Asteraceae and could play an important role not only in palynotaxonomy but also in allied fields.

Anisotropic Particle Deposition Kinetics from Quartz Crystal Microbalance Measurements: Beyond the Sphere Paradigm.

Deposition kinetics of polymer particles characterized by a prolate spheroid shape on gold sensors modified by the adsorption of poly(allylamine) was investigated using a quartz crystal microbalance and atomic force microscopy. Reference measurements were also performed for polymer particles of a spherical shape and the same diameter as the spheroid shorter axis. Primarily, the frequency and dissipation shifts for various overtones were measured as a function of time. These kinetic data were transformed into the dependence of the complex impedance, scaled up by the inertia impedance, upon the particle size to the hydrodynamic boundary layer ratio. The results obtained for low particle coverage were interpolated, which enabled the derivation of Sauerbrey-like equations, yielding the real particle coverage using the experimental frequency or dissipation (bandwidth) shifts. Experiments carried out for a long deposition time confirmed that, for spheroids, the imaginary and real impedance components were equal to each other for all overtones and for a large range of particle coverage. This result was explained in terms of a hydrodynamic, lubrication-like contact of particles with the sensor, enabling their sliding motion. In contrast, the experimental data obtained for spheres, where the impedance ratio was a complicated function of overtones and particle coverage, showed that the contact was rather stiff, preventing their motion over the sensor. It was concluded that results obtained in this work can be exploited as useful reference systems for a quantitative interpretation of bioparticle, especially bacteria, deposition kinetics on macroion-modified surfaces.

A taxonomic revision of Rhizophora L. (Rhizophoraceae) in Thailand.

A taxonomic revision of Rhizophora L. (Rhizophoraceae) in Thailand is presented. Two species, R. apiculata Blume and R. mucronata Poir., are enumerated with updated morphological descriptions, illustrations and a taxonomic identification key, together with notes on distributions, habitats and ecology, phenology, conservation assessments, etymology, vernacular names, uses, and specimens examined. Three names in Rhizophora, are lectotypified: R. apiculata and two associated synonyms of R. mucronata (i.e., R. latifolia Miq. and R. macrorrhiza Griff.). R. longissima Blanco, a synonym of R. mucronata, is neotypified. All two Rhizophora species have a conservation assessment of Least Concern (LC). Based on the morphological identification, these two species can be distinguished from one another by the shape and width of the leaf laminae and the length of a terminal stiff point of the leaf laminae; the type and position of the inflorescences and the number of flowers per inflorescence; the character and color of the bracteoles; the presence or absence of the flower pedicels; the shape of the mature flower buds; the shape, color, and texture of the sepals; the shape, character, and the presence or absence of hairs of the petals; the number of stamens per flower; the size of the fruits; the color and size of the hypocotyls; the color and diameter of the cotyledonous cylindrical tubes; and the color of the colleters and exudate. The thick cuticles, sunken stomata, large hypodermal cells, and cork warts are adaptive anatomical features of leaves in Rhizophora that live in the mangrove environments. The pollen grains of Thai Rhizophora species are tricolporate, prolate spheroidal or oblate spheroidal shapes, small-sized, and reticulate exine sculpturing.

Pollen morphology of selected species of native Amazonian fruit trees occurring in Brazil

Approximately 500 native edible fruits are known from Brazil with nearly 50% of these occurring in the Amazon. Pollen morphology of Brazilian plant species is poorly known yet it is important for scientific research. The aim of this study is to document the pollen morphology of 30 native edible fruit species belonging to 13 families. Following acetolysis the pollen was examined by light microscopy. Pollen grains ranged from small to very large. Prolate spheroidal and subprolate shapes predominated in most species, and most pollen grains had outline triangular to subtriangular. Polyads, tetrads and monads were observed, and the aperture arrangement varied from inarperturate to colpate and colporate, with the majority being 3-colporate and having a reticulate sexine. The species documented will contribute to pollen flora of Brazil and the information used in melissopalynollogical studies.

Morphological Features and Biological Activity of Different Extracts of Echinops spinosissimus Grown in Saudi Arabia

Based on a shortage of available data on Echinops spinosissimus in Saudi Arabia, the current study’s aim was to present some new information on the topic. Plant samples were collected from different locations in the northeast of Mecca. Out of fifteen species from this genus found in Saudi Arabia, one species was targeted in the current study. It was noted as a perennial subshrub that is 30–80 cm in length. Its stem is gray, striate, and slightly covered with glandular hairs. The epidermis is converted into cork cells in older stem parts. The vascular system showed a continuous siphonostelic structure and dissected vascular bundles. The lamina is abaxially rounded and straight. The pollen grains are monads, radially symmetric, medium-sized, and a prolate spheroidal shape with an aculeate–foveolate exine structure. Based on its historical pharmaceutical properties, the phytochemical properties were studied, and it was noted that ethyl acetate was the best solvent for producing high amounts of bioactive compounds such as phenols, flavonoids, and alkaloids. The obtained extracts appeared to exhibit high activity against Gram-positive pathogenic bacteria. These extracts were identified by using HPLC and GC-MS. Many bioactive compounds were detected, such as protocatechuic acid, gallic acid, rutin, vanillic acid, quercetin, and kaempferol. Additionally, four main compounds, including hexadecanoic, stearic, oleic, and linoleic acids, were detected via GC-MS. The total antioxidants of E. spinosissimus extracts showed that the ethyl acetate extract exhibited a high total antioxidant capacity and free radical-scavenging properties.

Prolate spheroidal quantum dot: Effect of dot size and eccentricity on confined energy states

We have explored the energy states of an electron trapped in a prolate spheroidal shape CdSe quantum dot (QD) within a finite barrier height, utilizing the Schrodinger equation in a prolate spheroidal coordinate system. The calculation of various eigen energy states have been performed as a function of the QD volume and spheroid eccentricity. Our findings demonstrate that with the increase in both the QD’s volume and the eccentricity, the confinement energy decreases. Furthermore, we discovered that for any given l value, the energy of states corresponding to higher and lower sublevels (m) decreases with an increase in eccentricity. However, the decrease in energy of sublevels with increasing eccentricity varied for different m values. Additionally, a comparison of the energy states of a confined electron in prolate spheroidal and spherical quantum dots revealed that they are located at different positions.

Mechanisms of Anisotropic Particle Deposition: Prolate Spheroid Layers on Mica

Anisotropic particle deposition was investigated using the streaming potential method complemented with the atomic force microscopy (AFM) determination of the absolute particle coverage. The polymer particles were synthesized using the stretching procedure with consecutive oxidation of surface hydroxyl groups and coupling of polyethyleneimine. The bulk particle physicochemical properties were characterized by scanning electron microscopy (SEM), dynamic light scattering, and laser Doppler velocimetry. The particles were positively charged in the pH range of 3–10, exhibiting a prolate spheroid shape with an axis ratio of five. Thorough AFM and in situ optical microscopy measurements yielded the adsorption kinetics of particles under the diffusion-controlled regime. The experimental data were adequately interpreted in terms of the random sequential adsorption model with the surface blocking function derived from the scaled particle theory. The root-mean-square (rms) parameter of the layers for a broad range of particle coverage was also determined and interpreted using the topographical model developed in this work. The experiments were complemented by the measurements of the streaming potential of particle layers under various ionic strengths and pHs. The ζ (zeta)-potential data acquired in this way enabled to determine the universal hydrodynamic function describing the dependence of the streaming potential on the particle coverage. The function was used to express the ζ-potential of surfaces covered by particles in terms of substrate rms. It was argued that the acquired results, in addition to being significanct to basic science, can be exploited as useful reference systems for quantitative interpretation of bioparticle deposition on abiotic surfaces.

Pollen Morphological Study of Some Selected Flowering Plants within Adekunle Ajasin University Main Campus, Akungba-Akoko, Ondo State, Nigeria

On the Adekunle Ajasin University Main campus, Akungba-Akoko, Ondo State, Nigeria, the pollen morphological study of seven (7) flowering plant species representing three (3) angiospermic plant Families (Asteraceae, Euphorbiaceae, and Fabaceae sub-family Caesalpinoideae) was examined, analyzed, and studied palynologically to determine the morphological features and attributes as an aid in the identification and classification of its members within each family. Pollen grains from fresh polleniferous materials were extracted using acetolysis methods. Detailed morphological evaluations were performed at x100 magnification. Results showed similarities and differences between species in the same genera, as well as differences between species in other families. Pollen study of these species revealed several similarities between species within the same family. Aperture type, forms, pollen grain size, sculpturing pattern, pollen dimension, and exine pattern were all studied for differences and similarities. Euphorbia hirta L and Euphorbia heterophylla L, both Euphorbiaceae species, have tricolpate apertures, are prolate in shape, reticulate, and contain small to medium pollen sizes. Asteraceae has tricolporate apertures, prolate spheroidal shapes, spinate, short and long spines, and pollen sizes ranging from microscopic to enormous (Ageratum conyzoides L, Tithonia diversifolia, and Tridax procumbens). Pollen from the family Fabaceae subfamily Caesalpinioideae (which includes Caesalpinia pulcherrima (L.) Swartz. and Senna alata (Linn.) Roxb) were found to be subprolate, coarsely reticulate, tricolporate, and with pollen sizes ranging from medium to large. Aperture measures such as number and diameter, pollen size, and spine height were suggestive in all of the species studied. Because all of the species studied exhibited comparable form and symmetry, they were grouped together and assigned to the same family.

QCM-D Investigations of Anisotropic Particle Deposition Kinetics: Evidences of the Hydrodynamic Slip Mechanisms.

Deposition kinetics of positively charged polymer microparticles, characterized by prolate spheroid shape, at silica and gold sensors was investigated using the quartz microbalance (QCM) technique. Reference measurements were also performed for positively charged polymer particles of spherical shape and the same mass as the spheroids. Primarily, the frequency and bandwidth shifts for various overtones were measured as a function of time. It is shown that the ratio of these signals is close to unity for all overtones. These results were converted to the dependence of the frequency shift on the particle coverage, directly determined by atomic force microscopy and theoretically interpreted in terms of the hydrodynamic model. A quantitative agreement with experiments was attained considering particle slip relative to the ambient oscillating flow. In contrast, the theoretical results pertinent to the rigid contact model proved inadequate. The particle deposition kinetics derived from the QCM method was compared with theoretical modeling performed according to the random sequential adsorption approach. This allowed to assess the feasibility of the QCM technique to furnish proper deposition kinetics for anisotropic particles. It is argued that the hydrodynamic slip effect should be considered in the interpretation of QCM kinetic results acquired for bioparticles, especially viruses.

Description of Limnomonas gen. nov., L. gaiensis sp. nov. and L. spitsbergensis sp. nov. (Chlamydomonadales, Chlorophyta)

Two novel Chlamydomonas-like species, belonging to the Moewusii clade, have been described. The first species inhabits eutrophic and neutral to basic pH waters in Sweden and England. It is easily recognizable under a light microscope due to its morphology (a small green prolate spheroidal shape with a large and truncated papilla at its anterior end, two equal flagella, a single lateral eyespot, a basal nucleus, and a well-defined pyrenoid) and to its peculiar whole-body pendulum movement while resting on surfaces or attached to floating particles. The species occurs as free-living individuals and is able to gather temporarily into groups of individual cells. No particular binding structures or palmelloid cells were observed in cultures. The second species, previously assigned to Chlamydomonas cf. proboscigera, was collected from persistent snow in Svalbard, Norway. Its morphology is revised herein. Using SSU rDNA sequence analyses, these two species formed a well-supported clade. Moreover, ITS-2 secondary structure analyses confirmed sexual incompatibility between these biological species. Considering these results, a new genus Limnomonas and its type species L. gaiensis and L. spitsbergensis are proposed.

Systematic reinstatement of the Sumatra endemic species Mangiferasumatrana Miq. (Anacardiaceae).

Mangiferasumatrana Miq. is an endemic species from Sumatra. The taxonomic status of M.sumatrana remains unclear and is currently treated as a synonym of M.laurina. The present study employed morphological and palynological characters and molecular analyses to address the delimitation between the two species. Pollen observations were carried out with a Scanning Electron Microscope (SEM). Phylogenetic relationships were investigated using the ITS and the trnl-F intergenic spacer markers. M.sumatrana differs from M.laurina by having pyramidal panicles with a low density of pale yellow flowers pale, sepals 3-3.5 × 1.7-2 mm, fruit roundish to flattened with pale yellow pulp, a rough fibre texture, and pollen with a prolate spheroidal shape. The MP phylogenetic tree showed a divergent boundary between the two species suggesting that M.sumatrana could be an independent species, not a variety of M.laurina. The present study supports the view that these two taxa can be treated as different species.

Soft Microswimmer Powered by Fluid Oscillation

In this letter, we review the results of our recent studies on a soft microswimmer powered by fluid oscillations. The microswimmer consists of an elastic membrane with a prolate spheroidal reference shape containing a rigid sphere. The swimming direction can be controlled by appropriately applying fluid oscillations. The obtained knowledge will be useful for future artificial microswimmer designs.

First Report and 3D Reconstruction of a Presumptive Microscopic Liver Lipoma in a Black Barbel (Barbus balcanicus) from the River Bregalnica in the Republic of North Macedonia

A lipoma is a benign tumour of mature adipocytes which may appear in various species, including marine and freshwater fish. It usually occurs in isolated locations, such as a superficial or deep mass, mainly in the skin and seldom in other organs. In non-mammalian vertebrates, there is no agreed minimal size for the mass to be considered a lipoma. This study histologically describes a case proposed to be a microlipoma in the liver of Barbus balcanicus. The structure was an oval-shaped mass of well-differentiated adipocytes, surrounded by hepatic parenchyma. The adipocyte cluster did not contact with major vascular or biliary tracts, the liver capsule, or the hilum. The cell mass reached a maximal linear length and width of ~0.5 mm and ~0.4 mm. A three-dimensional and software-assisted reconstruction of the adipocytic mass showed that it had the shape of a flattened prolate spheroid (~0.01 mm3). Given the histological criteria currently used in the literature, we consider the mass as a lipoma, or, better, a microlipoma because it was tiny. We interpret this structure as an early growing lipoma. This work is the second description of a liver lipoma in a fish to the best of our knowledge.

Study on SERS activity of Au-Ag bimetallic nanostructures synthesized using different reducing agents

Abstract The Au-Ag bimetallic nanostructures were synthesized independently using three different reducing agents [ascorbic acid (C6H8O6), sodium borohydride (NaBH4) and tri-sodium citrate dihydrate (C6H9Na3O9)] to understand their effect on the morphology of the nanostructures. The nanostructures obtained using the reducing agents mentioned in above order, were found in sprouted potato, cubical, and prolate spheroid (PS) shapes. All the synthesized nanostructures were characterized using energy-dispersive X-ray spectroscopy and extinction spectroscopy. The surface enhanced Raman scattering (SERS) activity of all these nanostructures was studied using Raman probe solutions with micro and nanomolar concentrations. Relatively, the PS shaped nanostructures were found to be more stable and better for SERS studies. Therefore, these nanostructures were further characterized by Transmission electron microscopy and X-ray photoelectron spectroscopy. The usefulness of PS shaped Au-Ag nanostructures was also demonstrated by recording the spectra of both methylene blue (MB) and 4-Aminothiophenol (4-ATP) solutions with femtomolar concentration. The experimental enhancement factor (EEF) was found to be around 1.1 × 1011 in case of MB solution with femtomolar concentration. The possible origin for the EEF is explained using quasi-static theory and Finite Element Method (FEM) based simulations.

Use of Pollen Morphology Traits for Identifying Species of Centaurea L. Asteraceae in Kurdistan-Iraq

The polleniferous material of Centaurea taxa grow in Kurdistan-Iraq was collected. Samples were tested using scanning electron microscopy (SEM) and light microscopy (LM). In the polar view, pollen grain outlines are mostly triangular or triangular-circular. In equatorial view, the elliptic shape is common, while circulars or semicircular shapes are rare. The exine sculpture is scabrate, and the tectum is perforate. Number of sculpture microspinules/ µm², and their heights together with the number of wall perforations provide significant characters for taxa delimitation. Pollen grains of all species are of medium size, very few of some species pollen are larger or smaller in size. Species producing subprolate pollen shape is common, while oblate spheroidal and Prolate spheroidal shapes are less common. The principal component analysis and the discriminant analysis can recognize 65.478% and 87.54% of the total variability respectively; moreover, the discriminant function can correctly classify 125 or 78.125% out of 160 observations for pollen traits.

Cell size influences inorganic carbon acquisition in artificially selected phytoplankton.

Cell size influences the rate at which phytoplankton assimilate dissolved inorganic carbon (DIC), but it is unclear whether volume-specific carbon uptake should be greater in smaller or larger cells. On the one hand, Fick's Law predicts smaller cells to have a superior diffusive CO2 supply. On the other, larger cells may have greater scope to invest metabolic energy to upregulate active transport per unit area through CO2 -concentrating mechanisms (CCMs). Previous studies have focused on among-species comparisons, which complicates disentangling the role of cell size from other covarying traits. In this study, we investigated the DIC assimilation of the green alga Dunaliella tertiolecta after using artificial selection to evolve a 9.3-fold difference in cell volume. We compared CO2 affinity, external carbonic anhydrase (CAext ), isotopic signatures (δ13 C) and growth among size-selected lineages. Evolving cells to larger sizes led to an upregulation of CCMs that improved the DIC uptake of this species, with higher CO2 affinity, higher CAext and higher δ13 C. Larger cells also achieved faster growth and higher maximum biovolume densities. We showed that evolutionary shifts in cell size can alter the efficiency of DIC uptake systems to influence the fitness of a phytoplankton species.

Convective and Microwave Assisted Drying of Wet Porous Materials with Prolate Spheroidal Shape: A Finite-Volume Approach

Convective heating is a traditional method used for the drying of wet porous materials. Currently, microwave drying has been employed for this purpose, due to its excellent characteristics of uniform moisture removal and heating inside the material, higher drying rate, and low energy demand. This paper focuses on the study of the combined convective and microwave drying of porous solids with prolate spheroidal shape. An advanced mathematical modeling based on the diffusion theory (mass and energy conservation equations) written in prolate spheroidal coordinates was derived and the numerical solution using the finite-volume method is presented. Here, we evaluated the effect of the heat and mass transport coefficients and microwave power intensity on the moisture removal and heating of the solid. Results of the drying and heating kinetics and the moisture and temperature distribution inside the solid are presented and discussed. It was verified that the higher the convective heat and mass transfer coefficients and microwave power intensity, the faster the solid will dry and heat up.

Age‐Related Loss of Phrenic Motor Neurons: Reduced Myogenic Influence?

There is an age‐associated loss of phrenic motor neurons (PhMNs) and withdrawal of pre‐synaptic terminals at neuromuscular junctions (NMJs) in 24‐month old Fischer 344 (F344) rats. Previously, we showed that age‐related PhMN loss is concomitant with neuromuscular transmission failure and diaphragm muscle (DIAm) sarcopenia (an age‐related atrophy of muscle fibers and a decrease in specific force). It is unknown if pre‐synaptic terminal withdrawal precedes PhMN loss, which would implicate a reduction in a trophic influence emanating from muscle fibers (myogenic). We hypothesized that age‐related PhMN loss results from pre‐synaptic terminal withdrawal and reduced myogenic influence, which occurs predominantly at type IIx and/or IIb DIAm fibers (innervated by larger PhMNs). F344 rats were obtained from the National Institutes of Aging. Experimental ages were chosen to represent 100% and 50% survival at 6 months and 24 months‐old, respectively. PhMNs were first retrogradely labeled by intrapleural injection of cholera toxin‐subunit B (CTB), which is dependent on binding to pre‐synaptic terminal gangliosides. Thus, with pre‐synaptic terminal withdrawal, PhMNs would not be labeled. Subsequently (3 days after CTB), PhMNs were retrogradely labeled by sectioning the phrenic nerve and dipping the proximal end into a Rhodamine dextran (Rho) solution – this labeling is not dependent on pre‐synaptic terminals. CTB and Rho labeled PhMNs were visualized by confocal microscopy. Only optical slices containing the nucleus of Rho‐ and/or CTB‐labeled PhMNs were counted. We analyzed the differences in labeling of PhMNs by CTB and Rho in both age groups. In labeled PhMNs, short and long axis measurements were used to determine somal surface areas by assuming a prolate spheroid shape. In 6‐month old rats, there was no significant difference in the number of PhMNs labeled by CTB or Rho. In 24‐month old rats, the total number of labeled PhMNs was reduced compared to the 6‐month old rats, which primarily affected larger PhMNs. Furthermore, at 24‐months, fewer PhMNs were labeled with CTB compared to Rho and those labeled with Rho had larger somal surface areas. These results support our hypothesis that the age‐related loss of larger PhMNs results from pre‐synaptic terminal withdrawal and reduced myogenic influence.Support or Funding InformationSupport: NIH R01‐AG044615American Physiological Society

Effect of non-spherical particles on burning behavior during aluminum combustion

The shape of an aluminum particle is assumed to be spherical or an equivalent sphere during the combustion process. Such an assumption lacks objectivity and leads to unreasonable approximations of burning efficiency and performance. To investigate the influence of non-spherical particles on burning behavior, this study focused on a theoretical and experimental investigation of the combustion of nanoscale aluminum ellipsoidal particles. Models for prolate and oblate spheroids in aluminum combustion were established to explore combustion properties such as mass release rate, linear burning rate, burning rate, and burnout time. To validate the theoretical results, combustion experiments were conducted on three samples. Reasonable agreement between the results of numerical simulation and experimental findings was obtained in terms of the particle burning characteristics. It was found that particle morphology (such as prolate or oblate spheroid shape) and size play a significant role in the combustion performance of nanosized aluminum particles.