scholarly journals The asynchronous growth and movement reconstruction of the early molting animals

2020 ◽  
Author(s):  
Tian Lan ◽  
Daniel Meulemans Medeiros
Keyword(s):  
Distribution Patterns ◽  
Cellular Level ◽  
The Body ◽  
Adjacent Cell ◽  
Early Cambrian ◽  
Active Tension ◽  
Cell Level ◽  
Cellular Resolutions ◽  
Physical Barriers ◽  
Epithelium Cells

Abstract Epithelium is one of the basic types of animal tissue, and forms tissue boundaries that act as physical barriers to separate adjacent cell clusters. However, tissue boundaries at cellular resolutions can hardly be found in the fossil record. Here we focus on the growth and movement patterns of early Ecdysozoans by quantifying cell-level forces in the epithelium of two worms from the early Cambrian and Ordovician period. The arrangement of the epithelium cells (that do not necessarily represent biological cells) separating the body rings of these early Ecdysozoans indicates precise morphological patterning at the cellular level was established in the early Cambrian. The force distribution patterns on the body ring further suggest that the boundary cells helped maintain a pressure gradient between the rings, consistent with a role in movement. Finally, the active tension field of the worms plates throughout their ontogeny, and steady state of their epithelium cells, indicate these molting animals employed an asynchronous growth pattern in their epithelium.

scholarly journals The asynchronous growth and movement reconstruction of the early molting animals

2020 ◽  
Author(s):  
Tian Lan
Keyword(s):  
Movement Pattern ◽  
Distribution Patterns ◽  
Building Blocks ◽  
Cellular Level ◽  
The Body ◽  
Early Cambrian ◽  
Ontogenetic Trajectory ◽  
Physical Barriers ◽  
Fossil Records ◽  
Epithelium Cells

Abstract Epithelium is one of the basic types of animal tissue, in which tissue boundaries are the physical barriers to separate adjust cell clusters. However, tissue boundary in cellular level can hardly found in the fossil records. Here I focus on the growth and movement patterns of the early Ecdysozoa being through quantifying forces in cellular level of the epithelium of two worms from the early Cambrian and Ordovician period. The epithelium cells (might be but not necessarily represent the biological cell) separate adjust body ring of the early Ecdysozoa indicates a precise morphological patterning in cellular level has been established in the early Cambrian. The forces distribution patterns on the body ring suggest the boundary cells are contribute to maintain pressure gradient among rings which are the building blocks of the movement pattern of the worm. The active tension field of the worms plates though ontogenetic trajectory while epithelium cells are in the steady state indicate these molting animals employ asynchronous growth pattern of the epithelium.

scholarly journals Dealing with PET radiometabolites

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Krishna Kanta Ghosh ◽  
Parasuraman Padmanabhan ◽  
Chang-Tong Yang ◽  
Sachin Mishra ◽  
Christer Halldin ◽  
...  
Keyword(s):  
Pet Imaging ◽  
Distribution Patterns ◽  
The Body ◽  
Analysis Process ◽  
Pet Tracer ◽  
Positron Emission ◽  
Structural Identity ◽  
Available Technology ◽  
Living Organisms ◽  
Entire Amount

Abstract Positron emission tomography (PET) offers the study of biochemical, physiological, and pharmacological functions at a cellular and molecular level. The performance of a PET study mostly depends on the used radiotracer of interest. However, the development of a novel PET tracer is very difficult, as it is required to fulfill a lot of important criteria. PET radiotracers usually encounter different chemical modifications including redox reaction, hydrolysis, decarboxylation, and various conjugation processes within living organisms. Due to this biotransformation, different chemical entities are produced, and the amount of the parent radiotracer is declined. Consequently, the signal measured by the PET scanner indicates the entire amount of radioactivity deposited in the tissue; however, it does not offer any indication about the chemical disposition of the parent radiotracer itself. From a radiopharmaceutical perspective, it is necessary to quantify the parent radiotracer’s fraction present in the tissue. Hence, the identification of radiometabolites of the radiotracers is vital for PET imaging. There are mainly two reasons for the chemical identification of PET radiometabolites: firstly, to determine the amount of parent radiotracers in plasma, and secondly, to rule out (if a radiometabolite enters the brain) or correct any radiometabolite accumulation in peripheral tissue. Besides, radiometabolite formations of the tracer might be of concern for the PET study, as the radiometabolic products may display considerably contrasting distribution patterns inside the body when compared with the radiotracer itself. Therefore, necessary information is needed about these biochemical transformations to understand the distribution of radioactivity throughout the body. Various published review articles on PET radiometabolites mainly focus on the sample preparation techniques and recently available technology to improve the radiometabolite analysis process. This article essentially summarizes the chemical and structural identity of the radiometabolites of various radiotracers including [11C]PBB3, [11C]flumazenil, [18F]FEPE2I, [11C]PBR28, [11C]MADAM, and (+)[18F]flubatine. Besides, the importance of radiometabolite analysis in PET imaging is also briefly summarized. Moreover, this review also highlights how a slight chemical modification could reduce the formation of radiometabolites, which could interfere with the results of PET imaging. Graphical abstract

scholarly journals Natural barriers: waterfall transit by small flying animals

2020 ◽  
Vol 7 (8) ◽  
pp. 201185
Author(s):  
Victor M. Ortega-Jimenez ◽  
Eva C. Herbst ◽  
Michelle S. Leung ◽  
Robert Dudley
Keyword(s):  
Complex Dynamics ◽  
Sister Group ◽  
The Body ◽  
Heterogeneous Structure ◽  
Flight Behaviour ◽  
Physical Constraints ◽  
Physical Barriers ◽  
Translational Speed ◽  
Geomorphological Features ◽  
Stroke Amplitude

Waterfalls are conspicuous geomorphological features with heterogeneous structure, complex dynamics and multiphase flows. Swifts, dippers and starlings are well-known to nest behind waterfalls, and have been reported to fly through them. For smaller fliers, by contrast, waterfalls seem to represent impenetrable barriers, but associated physical constraints and the kinematic responses of volant animals during transit are unknown. Here, we describe the flight behaviour of hummingbirds (the sister group to the swifts) and of various insect taxa as they fly through an artificial sheet waterfall. We additionally launched plastic balls at different speeds at the waterfall so as to assess the inertial dependence of sheet penetration. Hummingbirds were able to penetrate the waterfall with reductions in both their translational speed, and stroke amplitude. The body tilted more vertically and exhibited greater rotations in roll, pitch and yaw, along with increases in tail spread and pitch. The much smaller plastic balls and some flies moving at speeds greater than 2.3 m s −1 and 1.6 m s −1 , respectively, also overcame effects of surface tension and water momentum and passed through the waterfall; objects with lower momentum, by contrast, entered the sheet but then fell along with the moving water. Waterfalls can thus represent impenetrable physical barriers for small and slow animal fliers, and may also serve to exclude both predators and parasites from nests of some avian taxa.

The Japanese Village in the Seventeenth Century

1952 ◽  
Vol 12 (1) ◽  
pp. 1-20
Author(s):  
Thomas C. Smith
Keyword(s):  
Seventeenth Century ◽  
Middle Ages ◽  
The Body ◽  
Social Classes ◽  
Vital Function ◽  
The West ◽  
Social Body ◽  
The Social ◽  
Physical Barriers ◽  
The Middle Ages

As in the Middle Ages in the West, so in Tokugawa Japan (1600–1868) men were fond of explaining the hierarchical society in which they lived by comparing it to an organism. Social classes, Confucian scholars said, were like parts of the body: each had a vital function to perform, but their functions were essentially different and unequal in value. In this scheme the peasants were second in importance only to the ruling military class. Just as the samurai officials were the brains that guided other organs, so the peasants were the feet that held the social body erect. They were the “basis of the country,” the valued producers whose labor sustained all else. But, as a class, they tended innately to backsliding and extravagance. Left alone they would consume more than their share of the social income, ape the manners and tastes of their betters, and even encroach upon the functions of other classes to the perilous neglect of their own. Only the lash of necessity and the sharp eye of the official could hold them to their disagreeable role. They had to be bound to the land; social distinctions had to be thrown up around them like so many physical barriers; and, to remove all temptation to indolence and luxury, they had to be left only enough of what they produced to let them continue producing.

New well-preserved scleritomes of Chancelloriida from early Cambrian Guanshan Biota, eastern Yunnan, China

2018 ◽  
Vol 92 (6) ◽  
pp. 955-971 ◽  
Author(s):  
Jun Zhao ◽  
Guo-Biao Li ◽  
Paul A. Selden
Keyword(s):  
New Species ◽  
Detailed Comparison ◽  
The Body ◽  
Single Element ◽  
Early Cambrian ◽  
Top Down ◽  
Middle Cambrian ◽  
Unusual Form ◽  
Guanshan Biota ◽  
A New Species

AbstractA large number of well-preserved chancelloriid scleritomes from the Guanshan biota, early Cambrian of Yunnan, China, are described as a new species,Allonnia tenuisn. sp., and provide solid evidence for the original appearance of these enigmatic animals, based on specimens compacted laterally and top-down. With the assistance of a flexible integument, chancelloriids, especiallyAllonniafrom early and middle Cambrian, may have had the ability to partially or completely expand and contract the body, which might have played an important role in feeding. A new metazoan with single-element spines,Nidelric gaoloufangensisn. sp., is also described. Preservation and affinity are discussed. Detailed comparison of the morphology of the body and spines of this metazoan indicate that it shares many similarities with chancelloriids, of which it may be an unusual form.UUID:http://zoobank.org/2708d95a-1fae-46fc-afea-9707ae97a4d7

A single cell approach to problems of cell lineage and commitment during embryogenesis of Drosophila melanogaster

Development ◽  
1987 ◽  
Vol 100 (1) ◽  
pp. 1-12 ◽  
Author(s):  
G.M. Technau
Keyword(s):  
Drosophila Melanogaster ◽  
Single Cell ◽  
Cell Lineage ◽  
Cellular Level ◽  
Central Importance ◽  
Cell Level ◽  
Combined Application ◽  
A Cell ◽  
Pole Cells ◽  
Drosophila Embryos

The mechanisms leading to the commitment of a cell to a particular fate or to restrictions in its developmental potencies represent a problem of central importance in developmental biology. Both at the genetic and at the molecular level, studies addressing this topic using the fruitfly Drosophila melanogaster have advanced substantially, whereas, at the cellular level, experimental techniques have been most successfully applied to organisms composed of relatively large and accessible cells. The combined application of the different approaches to one system should improve our understanding of the process of commitment as a whole. Recently, a method has been devised to study cell lineage in Drosophila embryos at the single cell level. This method has been used to analyse the lineages, as well as the state of commitment of single cell progenitors from various ectodermal, mesodermal and endodermal anlagen and of the pole cells. The results obtained from a clonal analysis of wild-type larval structures are discussed in this review.

scholarly journals Physiological Responses of Jurkat Lymphocytes to Simulated Microgravity Conditions

2019 ◽  
Vol 20 (8) ◽  
pp. 1892 ◽  
Author(s):  
Caterina Morabito ◽  
Paola Lanuti ◽  
Giusy A. Caprara ◽  
Marco Marchisio ◽  
Mariano Bizzarri ◽  
...  
Keyword(s):  
Simulated Microgravity ◽  
Immune Cell ◽  
Cellular Level ◽  
The Body ◽  
Jurkat Cells ◽  
Cell Phenotype ◽  
Environmental Condition ◽  
Mitochondria Membrane Potential ◽  
Microgravity Conditions ◽  
External Forces

The presence of microgravity conditions deeply affects the human body functions at the systemic, organ and cellular levels. This study aimed to investigate the effects induced by simulated-microgravity on non-stimulated Jurkat lymphocytes, an immune cell phenotype considered as a biosensor of the body responses, in order to depict at the cellular level the effects of such a peculiar condition. Jurkat cells were grown at 1 g or on random positioning machine simulating microgravity. On these cells we performed: morphological, cell cycle and proliferation analyses using cytofluorimetric and staining protocols—intracellular Ca2+, reactive oxygen species (ROS), mitochondria membrane potential and O2− measurements using fluorescent probes—aconitase and mitochondria activity, glucose and lactate content using colorimetric assays. After the first exposure days, the cells showed a more homogeneous roundish shape, an increased proliferation rate, metabolic and detoxifying activity resulted in decreased intracellular Ca2+ and ROS. In the late exposure time, the cells adapted to the new environmental condition. Our non-activated proliferating Jurkat cells, even if responsive to altered external forces, adapted to the new environmental condition showing a healthy status. In order to define the cellular mechanism(s) triggered by microgravity, developing standardized experimental approaches and controlled cell culture and simulator conditions is strongly recommended.

The relation between connective tissue cells and intercellular substances, including basement membranes

1975 ◽  
Vol 271 (912) ◽  
pp. 363-377 ◽  
Keyword(s):  
Endothelial Cells ◽  
Basement Membrane ◽  
Immune Complexes ◽  
Hydrolytic Enzymes ◽  
Inflammatory Cells ◽  
Cell Types ◽  
Cellular Level ◽  
Basement Membranes ◽  
The Body ◽  
Pathological Changes

Basement membranes are distributed widely in the body forming an extracellular matrix for epithelial and endothelial cells. The collagenous and glycoprotein constituents of basement membranes are synthesized by these two cell types. Disturbance of the interactions between basement membranes and their associated epithelial and endothelial cells can lead to the pathological changes seen in diseases involving basement membranes. These changes are illustrated here by reference to glomerulonephritis induced by the deposition of immune complexes in the glomerulus of the kidney, and chronic inflammatory changes occurring in the lung after inhalation of asbestos. In these diseases basement membrane changes can occur in several ways. Hydrolytic enzymes released from inflammatory cells degrade basement membranes while other factors released from these cells may stimulate synthesis of basement membrane constituents by epithelial and endothelial cells. Alternatively the physical separation of epithelial and endothelial cells from their basement membranes by space-occupying substances such as immune complexes can interfere with feedback mechanisms leading to synthesis of basement membrane constituents and cell proliferation. Studies of these pathological changes at a cellular level should shed new light on the ways in which cells interact with their pericellular environment.

Nanotechnology: A Novel Approach for Drug Development in Health Care System

2020 ◽  
Vol 5 (1) ◽  
pp. 12-25
Author(s):  
Biswa M. Sahoo ◽  
Bera V.V.R. Kumar ◽  
Ch. Niranjan Patra ◽  
Jnyanaranjan R. Panda ◽  
Bibhash C. Mohanta ◽  
...  
Keyword(s):  
Health Care ◽  
Health Care System ◽  
Environmental Changes ◽  
Cellular Level ◽  
The Body ◽  
Health Science ◽  
Human Beings ◽  
Novel Approach ◽  
Parkinson’S Diseases ◽  
Care System

Background: Health is a lively state of the body which adjusts and adopt with the response to various environmental changes. There are several features that can influence the health status of human beings. Therefore, the continuous research study is highly essential to maintain a proper health care system in the community. Objective: The diverse area of innovation was made in nanotechnology for diagnosis and treatment of life-threatening diseases, such as obesity, diabetes, cardiovascular disorders, cancer, leukemia, neurodegenerative disorders like Alzheimer's disease and Parkinson's diseases, etc. Nanotechnology generally refers to the materials, devices, and systems in nanoscale which provides considerably improved physical, chemical and biological property. Methods: It is technology which deals with the design, synthesis, characterization of substances, devices and systems by arranging shape and size at their nanometer scale. It involves multidisciplinary research which includes both health science and technology for the treatment of human health. Nanotechnology can be applied at the cellular level in the human body with a high degree of specificity to treat the various diseases. Conclusion: This technology is potentially targeted to diseased tissue to achieve maximum therapeutic efficacy with fewer side effects. Nowadays, the rapidity of revolutionary discoveries in the field of nanotechnology is expected to accelerate in the next decade globally.

scholarly journals Always a price to pay: hibernation at low temperatures comes with a trade-off between energy savings and telomere damage

2019 ◽  
Vol 15 (10) ◽  
pp. 20190466 ◽  
Author(s):  
Julia Nowack ◽  
Iris Tarmann ◽  
Franz Hoelzl ◽  
Steve Smith ◽  
Sylvain Giroud ◽  
...  
Keyword(s):  
Body Temperature ◽  
Low Temperatures ◽  
Energy Demand ◽  
Energy Savings ◽  
High Energy ◽  
Cellular Level ◽  
The Body ◽  
Temperature Differential ◽  
Lower Temperature ◽  
Telomere Dynamics

We experimentally tested the costs of deep torpor at low temperatures by comparing telomere dynamics in two species of rodents hibernating at either 3 or 14°C. Our data show that hibernators kept at the warmer temperature had higher arousal frequencies, but maintained longer telomeres than individuals hibernating at the colder temperature. We suggest that the high-energy demand of frequent arousals is counteracted by a lower temperature differential between torpid and euthermic body temperature and that telomere length is restored during arousals when the body temperature is returned to normothermic values. Taken together, our study shows that hibernation at low body temperatures comes with costs on a cellular level and that hibernators need to actively counterbalance the shortening of telomeres.

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