scholarly journals Calcium Transport along the Axial Canal in Acropora

2021 ◽  
Author(s):  
Yixin Li ◽  
Xin Liao ◽  
Chunpeng He ◽  
Zuhong Lu
Keyword(s):  
Calcium Transport ◽  
Morphological Changes ◽  
Volume Ratio ◽  
Micro Computed Tomography ◽  
Initial State ◽  
Coral Colony ◽  
Branch Formation ◽  
Axial Canal ◽  
Calcareous Deposits ◽  
Canal Network

In Acropora, the complex canals in a coral colony connect all polyps into a holistic network to collaborate in performing biological processes. There are various types of canals, including calice, axial canals, and other internal canals, with structures that are dynamically altered during different coral growth states due to internal calcium transport. However, few studies have considered the regulation of calcium transport in Acropora. In this study, we investigated the morphological changes of the axial canal in six Acropora muricata samples by high resolution micro-computed tomography, observing the patterns of the axial canal during the processes of new branch formation and truncated branch rebuilding. We visualized the formation of a new branch from a calice and deposition of the iconic hexactin skeletons in the axial canal. Furthermore, the diameter and volume changes of the axial canal in truncated branches during rebuilding processes were calculated, revealing that the volume ratio of calcareous deposits in the axial canal exhibit significant increases within the first three weeks, returning to levels in the initial state in the following week. This work indicates that the axial canal can transport calcium to form hexactin skeletons in a new branch and rebuild the tip of a truncated branch. The calcium transport along canal network regulates various growth processes, including budding, branching, skeleton forming, and self-rebuilding of an Acropora colony. Understanding the changes in canal function under normal and extreme conditions will provide theoretical guidance for restoration and protection of coral reefs.

scholarly journals Calcium Transport along the Axial Canal in Acropora

Diversity ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 407
Author(s):  
Yixin Li ◽  
Xin Liao ◽  
Chunpeng He ◽  
Zuhong Lu
Keyword(s):  
Calcium Carbonate ◽  
Calcium Transport ◽  
Morphological Changes ◽  
Volume Ratio ◽  
Micro Computed Tomography ◽  
Initial State ◽  
Coral Colony ◽  
Carbonate Deposition ◽  
Axial Canal ◽  
Calcium Carbonate Deposition

In Acropora, the complex canals in a coral colony connect all polyps to a holistic network, enabling them to collaborate in performing biological processes. There are various types of canals, including calice, axial canals, and other internal canals, with structures that are dynamically altered during different coral growth states due to internal calcium transport. In this study, we investigated the morphological changes in the corallite of six Acropora muricata samples by high resolution micro-computed tomography, observing the patterns of calcium carbonate deposition within axial corallite during processes of new branch formation and truncated tip repair. We visualized the formation of a new branch from a calice and the calcium carbonate deposition in the axial canal. Furthermore, the diameter and volume changes of the axial canal in truncated branches during rebuilding processes were calculated, revealing that the volume ratio of calcareous deposits in the axial canal exhibit significant increases within the first three weeks, returning to levels in the initial state in the following week. This work demonstrates that calcium carbonate can be stored temporarily and then remobilized as needed for rapid growth. The results of this study shed light on the control of calcium carbonate deposition and growth of the axial corallite in Acropora.

scholarly journals Axial Canal Regulates the Processes of Coral Branching and Calcareous Transportation in Acropora

2021 ◽  
Author(s):  
Yixin Li ◽  
Tingyu Han ◽  
Chunpeng He ◽  
Zuhong Lu
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Transport System ◽  
Radial Symmetry ◽  
Growth Patterns ◽  
Coral Growth ◽  
Biological Processes ◽  
Micro Computed Tomography ◽  
Coral Colony ◽  
Axial Canal

In Acropora, the complex canals in a coral colony connect all polyps into a holistic network to collaborate in performing biological processes, while axial canal is the largest canal amongst the network and distributes at the center of a coral branch. However, previous studies indicated that, in the non-radial symmetry transport system of Acropora, axial canal do not play a major role in the transport of hydroplasm, and the action of axial canal in coral growth is still obscure. In this study, we reconstructed six Acropora muricata samples by high resolution micro-computed tomography to investigate the growth patterns of axial canals during the processes of new branch forming and truncated branch rebuilding. We found that the axial canal of a new branch is transformed from a calice and the polyps in the new branch are budded from the polyp in the axial canal. Meanwhile, the axial canal can transport the calcareous skeletons to rebuild the tip of a truncated branch, which represents as the change in the diameter of axial canal and calcareous deposition/reduction in it. This work indicate the regulation of axial canal in the growth processes including budding, branching, and mineralising of an Acropora colony.

scholarly journals Effect of Various Types of Muscle Contraction with Different Running Conditions on Mouse Humerus Morphology

Life ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 284
Author(s):  
Kaichi Ozone ◽  
Yuichiro Oka ◽  
Yuki Minegishi ◽  
Takuma Kano ◽  
Takanori Kokubun ◽  
...  
Keyword(s):  
Bone Formation ◽  
Muscle Contraction ◽  
Morphological Changes ◽  
Control Level ◽  
Volume Ratio ◽  
Tartrate Resistant Acid Phosphatase ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Bone Morphology ◽  
Attachment Region

How various types of muscle contraction during exercises affect bone formation remains unclear. This study aimed to determine how exercises with different muscle contraction types affect bone morphology. In total, 20 mice were used and divided into four groups: Control, Level, Down Slow, and Down. Different types of muscle contraction were induced by changing the running angle of the treadmill. After the intervention, micro-computed tomography (Micro-CT), tartrate-resistant acid phosphatase/alkaline phosphatase (ALP) staining, and immunohistochemical staining were used to analyze the humerus head, tendon-to-bone attachment, and humerus diaphyseal region. Micro-CT found that the volume ratio of the humeral head, the volume of the tendon-to-bone attachment region, and the area of the humeral diaphyseal region increased in the Down group. However, no difference was detected in bone morphology between the Level and Down Slow groups. In addition, histology showed activation of ALP in the subarticular subchondral region in the Down Slow and Down groups and the fibrocartilage region in the tendon-to-bone attachment. Moreover, Osterix increased predominantly in the Down Slow and Down groups.Overall bone morphological changes in the humerus occur only when overuse is added to EC-dominant activity. Furthermore, different type of muscle contractile activities might promote bone formation in a site-specific manner.

scholarly journals Micro-Computed Tomography Analysis of Subchondral Bone Regeneration Using Osteochondral Scaffolds in an Ovine Condyle Model

2021 ◽  
Vol 11 (3) ◽  
pp. 891
Author(s):  
Taylor Flaherty ◽  
Maryam Tamaddon ◽  
Chaozong Liu
Keyword(s):  
Computed Tomography ◽  
Bone Regeneration ◽  
Subchondral Bone ◽  
Volume Ratio ◽  
Bone Volume ◽  
Osteochondral Defects ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Trabecular Thickness ◽  
Osteochondral Scaffold

Osteochondral scaffold technology has emerged as a promising therapy for repairing osteochondral defects. Recent research suggests that seeding osteochondral scaffolds with bone marrow concentrate (BMC) may enhance tissue regeneration. To examine this hypothesis, this study examined subchondral bone regeneration in scaffolds with and without BMC. Ovine stifle condyle models were used for the in vivo study. Two scaffold systems (8 mm diameter and 10 mm thick) with and without BMC were implanted into the femoral condyle, and the tissues were retrieved after six months. The retrieved femoral condyles (with scaffold in) were examined using micro-computed tomography scans (micro-CT), and the micro-CT data were further analysed by ImageJ with respect to trabecular thickness, bone volume to total volume ratio (BV/TV) ratio, and degree of anisotropy of bone. Statistical analysis compared bone regeneration between scaffold groups and sub-set regions. These results were mostly insignificant (p < 0.05), with the exception of bone volume to total volume ratio when comparing scaffold composition and sub-set region. Additional trends in the data were observed. These results suggest that the scaffold composition and addition of BMC did not significantly affect bone regeneration in osteochondral defects after six months. However, this research provides data which may guide the development of future treatments.

3D-printed Poly-Lactic Co-Glycolic Acid (PLGA) scaffolds in non-critical bone defects impede bone regeneration in rabbit tibia bone

2021 ◽  
pp. 1-7
Author(s):  
Jin Xi Lim ◽  
Min He ◽  
Alphonsus Khin Sze Chong
Keyword(s):  
Computed Tomography ◽  
Bone Regeneration ◽  
Bone Defect ◽  
Volume Ratio ◽  
Bone Defects ◽  
Control Group ◽  
Micro Computed Tomography ◽  
Rabbit Tibia ◽  
3D Printed ◽  
Critical Bone Defects

BACKGROUND: An increasing number of bone graft materials are commercially available and vary in their composition, mechanism of action, costs, and indications. OBJECTIVE: A commercially available PLGA scaffold produced using 3D printing technology has been used to promote the preservation of the alveolar socket after tooth extraction. We examined its influence on bone regeneration in long bones of New Zealand White rabbits. METHODS: 5.0-mm-diameter circular defects were created on the tibia bones of eight rabbits. Two groups were studied: (1) control group, in which the bone defects were left empty; (2) scaffold group, in which the PLGA scaffolds were implanted into the bone defect. Radiography was performed every two weeks postoperatively. After sacrifice, bone specimens were isolated and examined by micro-computed tomography and histology. RESULTS: Scaffolds were not degraded by eight weeks after surgery. Micro-computed tomography and histology showed that in the region of bone defects that was occupied by scaffolds, bone regeneration was compromised and the total bone volume/total volume ratio (BV/TV) was significantly lower. CONCLUSION: The implantation of this scaffold impedes bone regeneration in a non-critical bone defect. Implantation of bone scaffolds, if unnecessary, lead to a slower rate of fracture healing.

Dynamics and 2D temperature distribution of plasma obtained by femtosecond laser-induced breakdown

2021 ◽  
Author(s):  
Afaque M. Hossain ◽  
Martin Ehrhardt ◽  
Martin Rudolph ◽  
Dmitry V Kalanov ◽  
Pierre Lorenz ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Morphological Changes ◽  
Exponential Dependence ◽  
Morphological Development ◽  
Initial State ◽  
Toroidal Plasma ◽  
Velocity Gradients ◽  
Baroclinic Torque ◽  
Laser Induced Breakdown ◽  
High Pressure Zone

Abstract Recently, plasma produced by focusing femtosecond laser in gases has been introduced as an etching tool in materials processing. Proper control of the plasma in this application necessitates the apt understanding of the different morphological features of the plasma. In this contribution we show that, the plasma produced in air goes through several stages of morphological development – from ellipsoidal to spherical to toroidal plasma, whereas in argon, axial compression of an ellipsoidal plasma is observed. To explain this dissimilarity, we have quantified the temperature by emission spectroscopy (Planck analysis with Wien’s approximation). The evolution of temperature shows a triple exponential dependence in time which can be correlated with different stages of morphological changes of the plasma. Open Source Field Operation and Manipulation (OpenFOAM) simulations using experimentally determined temperature values show that – (i) the reverse pressure gradient propagates radially inwards and compresses the plasma in both air and argon and forms a localized high pressure zone at the center that generates a secondary pressure wave in air, but not in argon, and (ii) the baroclinic torque that is generated because of the Richtmyer-Meshkov instability, dominates the rate of vorticity in air, whereas effects of flow compressibility and velocity gradients dominate the vortices in argon. Knowledge of the initial state and the dynamics of the subsequent stages of the plasma formation can be utilized for control and optimization of laser-induced plasma applications.

Membrane dynamics in relation to fluid absorption in reptilian proximal renal tubules

1989 ◽  
Vol 257 (5) ◽  
pp. R982-R988
Author(s):  
W. H. Dantzler
Keyword(s):  
Cell Volume ◽  
Morphological Changes ◽  
Apical Cell ◽  
Volume Ratio ◽  
Membrane Dynamics ◽  
Renal Tubules ◽  
Fluid Absorption ◽  
Bathing Medium ◽  
Membrane Area ◽  
Permissive Role

Net fluid absorption (Jv), cell volume, and cell membrane area have been studied in isolated, perfused snake (Thamnophis spp.) proximal tubules. With Na+ in both perfusate and bathing medium, Jv averages approximately 0.9 nl.min-1.mm-1. When choline replaces Na+ in perfusate, Jv nearly ceases. When choline also replaces Na+ in bathing medium, so that both solutions are identical, Jv returns to the control rate. The results are the same when tetramethylammonium replaces Na+, when sucrose replaces Na+ and the equivalent amount of Cl-, and when methyl sulfate replaces Cl- alone. However, when Li+ replaces Na+ in perfusate alone or in both perfusate and bathing medium, Jv is unchanged. Jv at control rates is isosmotic and can be partially inhibited by cold and cyanide. When choline replaces Na+ in perfusate and bathing medium, cell volume doubles, and intercellular space volume nearly quintuples. The areas of the lateral and apical cell membranes also approximately double, so that the surface area-to-volume ratio remains constant. These morphological changes in the absence of Na+ occur concomitantly with maintenance of Jv, suggesting that they may play a permissive role in such maintenance.

scholarly journals Impact of DBBM Fragments on the Porosity of the Calvarial Bone: A Pilot Study on Mice

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4748
Author(s):  
Ulrike Kuchler ◽  
Patrick Heimel ◽  
Alexandra Stähli ◽  
Franz Josef Strauss ◽  
Bernadette Luza ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Histological Evaluation ◽  
Random Allocation ◽  
Bovine Bone ◽  
Distribution Analysis ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Calvarial Bone ◽  
Ct Analysis ◽  
Bovine Bone Mineral

Deproteinized bovine bone mineral (DBBM) is brittle and can break into fragments. Here, we examined whether DBBM fragments have an impact on mice calvarial bone during bone augmentation. DBBM was either randomly crushed (DBBM fragments) or left undisturbed (DBBM granules). Then, DBBM fragments or original DBBM granules were placed onto calvarial bone in 20 BALB/c mice. Following random allocation, ten mice received DBBM fragments and ten mice received original DBBM granules. After fourteen days of healing, micro computed tomography (micro-CT) and histological analysis of the augmented sites were performed. The primary outcome was the porosity of the calvarial bone. The micro-CT analysis revealed that DBBM fragments failed to significantly change the porosity of the calvarial bone as compared with original DBBM granules, despite the slightly higher bone resorption in the DBBM fragment group, 10.3% (CI 6.3–11.6) versus 6.1% (CI 4.1–7.8, p = 0.355), respectively. The cortical bone volume was not altered by DBBM fragments as compared with original DBBM granules, i.e., 79.0% (CI 78.9–81.2) versus 81.5% (CI 80.1–83.3, p = 0.357), respectively. The DBBM fragment group revealed similar bone thickness values as compared with the DBBM granules group, i.e., 0.26 mm (CI 0.23–0.29) versus 0.25 mm (CI 0.22–0.27, p = 0.641), respectively. The histological evaluation supported the micro-CT observations, displaying minor signs of porosity and resorption. The particle-size distribution analysis confirmed a shift towards smaller particle sizes in the DBBM fragment group. These findings suggest that DBBM fragments behave similarly to original DBBM granules in terms of bone morphological changes at augmented sites.

scholarly journals Heterochronic Shifts Mediate Ecomorphological Convergence in Skull Shape of Microcephalic Sea Snakes

2019 ◽  
Vol 59 (3) ◽  
pp. 616-624 ◽  
Author(s):  
Emma Sherratt ◽  
Kate L Sanders ◽  
Amy Watson ◽  
Mark N Hutchinson ◽  
Michael S Y Lee ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Shape Variation ◽  
Micro Computed Tomography ◽  
Trophic Specialization ◽  
Evolutionary Patterns ◽  
Dietary Specialization ◽  
Geometric Morphometric ◽  
Sea Snakes ◽  
Morphometric Methods ◽  
Cranial Shape

Abstract Morphological variation among the viviparous sea snakes (Hydrophiinae), a clade of fully aquatic elapid snakes, includes an extreme “microcephalic” ecomorph that has a very small head atop a narrow forebody, while the hind body is much thicker (up to three times the forebody girth). Previous research has demonstrated that this morphology has evolved at least nine times as a consequence of dietary specialization on burrowing eels, and has also examined morphological changes to the vertebral column underlying this body shape. The question addressed in this study is what happens to the skull during this extreme evolutionary change? Here we use X-ray micro-computed tomography and geometric morphometric methods to characterize cranial shape variation in 30 species of sea snakes. We investigate ontogenetic and evolutionary patterns of cranial shape diversity to understand whether cranial shape is predicted by dietary specialization, and examine whether cranial shape of microcephalic species may be a result of heterochronic processes. We show that the diminutive cranial size of microcephalic species has a convergent shape that is correlated with trophic specialization to burrowing prey. Furthermore, their cranial shape is predictable for their size and very similar to that of juvenile individuals of closely related but non-microcephalic sea snakes. Our findings suggest that heterochronic changes (resulting in pedomorphosis) have driven cranial shape convergence in response to dietary specializations in sea snakes.

Modifications ultrastructurales de graines d'Allium cepa, hydratées ou non, soumises à de basses températures (−196 °C)

1980 ◽  
Vol 58 (22) ◽  
pp. 2367-2379
Author(s):  
Monique Colson
Keyword(s):  
Endoplasmic Reticulum ◽  
Liquid Nitrogen ◽  
Allium Cepa ◽  
Ultrastructural Study ◽  
Morphological Changes ◽  
Quiescent State ◽  
Glutaraldehyde Fixation ◽  
Initial State ◽  
Structural Alterations ◽  
Lamellar Structures

Osmic fixation was used in an ultrastructural study of Allium cepa seeds, both in the quiescent state and at the beginning of imbibition, in order to complete earlier observations made after glutaraldehyde fixation. In embryonic radicles, various groups of weakly stained lamellar structures looked like endoplasmic reticulum profiles. In these quiescent tissues, osmic fixation revealed many vesicles which appeared to be atypical elements of endoplasmic reticulum.In the first few hours of imbibition, reactive structures were more numerous and more diverse. Cisternae and vesicles of endoplasmic reticulum became typical looking, such as classically described in active tissues of other species.When Allium cepa seeds were treated with liquid nitrogen (−196 °C), induced structural alterations depended on the initial state of hydration. Lamellar systems underwent morphological changes. Osmic fixation showed the presence of numerous opaque globules throughout the cytoplasm. These globules seemed to derive from cisternae that appeared to have become fragmented during freezing. [Journal translation]

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