scholarly journals On the inference of function from structure using biomechanical modelling and simulation of extinct organisms

2011 ◽  
Vol 8 (1) ◽  
pp. 115-118 ◽  
Author(s):  
John R. Hutchinson
Keyword(s):  
Sensitivity Analysis ◽  
Broad Spectrum ◽  
Structure And Function ◽  
Modelling And Simulation ◽  
Model Design ◽  
Unknown Parameters ◽  
Simulation Techniques ◽  
Biomechanical Modelling ◽  
The Many ◽  
And Function

Biomechanical modelling and simulation techniques offer some hope for unravelling the complex inter-relationships of structure and function perhaps even for extinct organisms, but have their limitations owing to this complexity and the many unknown parameters for fossil taxa. Validation and sensitivity analysis are two indispensable approaches for quantifying the accuracy and reliability of such models or simulations. But there are other subtleties in biomechanical modelling that include investigator judgements about the level of simplicity versus complexity in model design or how uncertainty and subjectivity are dealt with. Furthermore, investigator attitudes toward models encompass a broad spectrum between extreme credulity and nihilism, influencing how modelling is conducted and perceived. Fundamentally, more data and more testing of methodology are required for the field to mature and build confidence in its inferences.

scholarly journals Implementation of Inquiry Method on Students' Critical Thinking Ability in the Concept of Structure and Function of Plant Networks

2019 ◽  
Vol 1 (4) ◽  
Author(s):  
Nurlena Andalia ◽  
Muhammad Ridhwan ◽  
Roslina Roslina ◽  
Nur Afni ◽  
Burhanuddin AG
Keyword(s):  
Critical Thinking ◽  
Thinking Skills ◽  
Structure And Function ◽  
Critical Thinking Skills ◽  
Plant Tissues ◽  
Average Value ◽  
Thinking Ability ◽  
Inquiry Method ◽  
The Many ◽  
And Function

This study aims to determine the implementation of inquiry methods that can improve students' critical thinking skills on the concept of structure and function of plant tissues at the Sekolah Keberbakatan Olah Raga Negeri Aceh (Aceh State Sports School). The population of this research is the many 112 students of class XI of the Sekolah Keberbakatan Olah Raga Negeri Aceh. The sample in this study were 26 students in class XI-1 as an experimental class and 26 students in class XI-2 as a control class. The method used is a descriptive method with a structural approach. Data collection is done by test techniques and data processing using the t-test formula. The results of the data analysis showed that the average ability or average value of class XI-1 students of the Sekolah Keberbakatan Olah Raga Negeri Aceh in taking the test received 80.7. While the average value of class XI-2 students of the Sekolah Keberbakatan Olah Raga Negeri Aceh in taking the test gets 70. Based on the price of t-counts and t-tables at a significant level of 0.05 with db: 50 of the sample class XI, then t- the count is 6.40 and the t-table is 1.66. So that the hypothesis proposed the implementation of inquiry methods can improve students' critical thinking skills on the concept of the structure and function of plant tissues in the Sekolah Keberbakatan Olah Raga Negeri Aceh is Accepted. It is recommended that this research can increase knowledge through the use of inquiry methods in all biological science subject matter.

scholarly journals The Cytoskeleton and Its Roles in Self-Organization Phenomena: Insights from Xenopus Egg Extracts

Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2197
Author(s):  
Zachary M. Geisterfer ◽  
Gabriel Guilloux ◽  
Jesse C. Gatlin ◽  
Romain Gibeaux
Keyword(s):  
Experimental System ◽  
Structure And Function ◽  
Self Organization ◽  
African Clawed Frog ◽  
Egg Extracts ◽  
Xenopus Egg ◽  
The Many ◽  
And Function ◽  
Xenopus Egg Extracts ◽  
Clawed Frog

Self-organization of and by the cytoskeleton is central to the biology of the cell. Since their introduction in the early 1980s, cytoplasmic extracts derived from the eggs of the African clawed-frog, Xenopus laevis, have flourished as a major experimental system to study the various facets of cytoskeleton-dependent self-organization. Over the years, the many investigations that have used these extracts uniquely benefited from their simplified cell cycle, large experimental volumes, biochemical tractability and cell-free nature. Here, we review the contributions of egg extracts to our understanding of the cytoplasmic aspects of self-organization by the microtubule and the actomyosin cytoskeletons as well as the importance of cytoskeletal filaments in organizing nuclear structure and function.

scholarly journals Extensive and diverse patterns of cell death sculpt neural networks in insects

2019 ◽  
Author(s):  
Sinziana Pop ◽  
Chin-Lin Chen ◽  
Connor J Sproston ◽  
Shu Kondo ◽  
Pavan Ramdya ◽  
...  
Keyword(s):  
Neural Networks ◽  
Cell Death ◽  
Programmed Cell Death ◽  
Neural Activity ◽  
Structure And Function ◽  
Evolutionary Adaptation ◽  
Cell Numbers ◽  
The Many ◽  
And Function ◽  
Evolutionary Role

ABSTRACTChanges to the structure and function of neural networks are thought to underlie the evolutionary adaptation of animal behaviours. Among the many developmental phenomena that generate change programmed cell death appears to play a key role. We show that cell death occurs continuously throughout insect neurogenesis and happens soon after neurons are born. Focusing on two dipterans which have lost flight during evolution we reveal that reductions in populations of flight interneurons are likely caused by increased cell death during development.Mimicking an evolutionary role for increasing cell numbers, we artificially block programmed cell death in the medial neuroblast lineage in Drosophila melanogaster, which results in the production of ‘undead’ neurons with complex arborisations and distinct neurotransmitter identities. Activation of these ‘undead’ neurons and recordings of neural activity in behaving animals demonstrate that they are functional. Our findings suggest that the evolutionary modulation of death-based patterning could generate novel network configurations.

scholarly journals Studies on the relation of gonadic structure to plumage characterisation in the domestic fowl.—II. The developmental capon and poularde

1927 ◽  
Vol 101 (711) ◽  
pp. 450-462 ◽  
Keyword(s):  
Domestic Fowl ◽  
Structure And Function ◽  
Complete Suppression ◽  
Male Characters ◽  
History Of Disease ◽  
History Of ◽  
Males And Females ◽  
The Many ◽  
And Function ◽  
Or History

Among the many sexually abnormal fowls sent to this Department during the last five years by poultry keepers interested in the science of breeding have been eleven birds which together form a distinct class. Instead of developing into normal cocks or hens with appropriate male or female plumage and head furnishings as they approached maturity, these birds assumed, and retained throughout their lives, the characters and behaviour of the fowl completely gonadectomised before puberty. There was never any reason to assume that the underlying physiological inactivity or actual absence of the gonads was other than the result of some developmental disharmony. No sign or history of disease was ever presented. Our knowledge of the adult characterisation of the fowl experimentally gonadectomised when a few days old, allowed us to recognise that in this group of sexually abnormal birds there were genetic males and females in which the gonadic tissues had been absent or functionally insufficient throughout their lives. In one respect only did these birds (save one) differ from the experimental capon and poularde; their combs were not bloodless and scaly, they were bright and healthy-looking, though very diminutive. After having been kept under observation for two years or more, the birds were killed. Post-mortem examination confirmed our anticipations. In all, there was either complete suppression or else very considerable reduction of gonadic tissue. Such cases as these have an important bearing upon the problem of the relation of gonadic structure and function to plumage characterisation in the fowl. The following cases of gonadic suppression and reduction in birds have been recorded : one duck, Netta rufina, with imperfect male characters and no gonads (Poll, 1909); four pheasant hybrids, Phasianus torquatus X P . colchicus (?) (Smith and Haig Thomas, 1913); Syrmatiens recessi X Phasianus principalis , reciprocal crosses, all females had small flaccid oviduct but no gonadic tissue (Phillips, 1916); pigeons and ringdoves, pure bred and hybrid, sixteen with no gonads, fifteen in which one gonad was abnormally absent, seventeen in which various degrees of reduction in the size of the gonads were exhibited (Riddle, 1925).

scholarly journals Advances in the study of bat flight: the wing and the wind

2015 ◽  
Vol 93 (12) ◽  
pp. 977-990 ◽  
Author(s):  
S.M. Swartz ◽  
N. Konow
Keyword(s):  
High Speed ◽  
Structure And Function ◽  
Experimental Fluid Dynamics ◽  
Flight Energetics ◽  
Wing Structure ◽  
The Many ◽  
Structural Architecture ◽  
And Function ◽  
Bat Evolution ◽  
Experimental Fluid

Bats are diverse, speciose, and inhabit most of earth’s habitats, aided by powered flapping flight. The many traits that enable flight in these mammals have long attracted popular and research interest, but recent technological and conceptual advances have provided investigators with new kinds of information concerning diverse aspects of flight biology. As a consequence of these new data, our understanding of how bats fly has begun to undergo fundamental changes. Physical and neural science approaches are now beginning to inform understanding of structural architecture of wings. High-speed videography is dramatically expanding documentation of how bats fly. Experimental fluid dynamics and innovative physiological techniques profoundly influence how we interpret the ways bats produce aerodynamic forces as they execute distinctive flight behaviors and the mechanisms that underlie flight energetics. Here, we review how recent bat flight research has provided significant new insights into several important aspects of bat flight structure and function. We suggest that information coming from novel approaches offer opportunities to interconnect studies of wing structure, aerodynamics, and physiology more effectively, and to connect flight biology to newly emerging studies of bat evolution and ecology.

scholarly journals IV. Structure and function of the organs of feeding and digestion in the septibranchs, Cuspidaria and Poromya

1928 ◽  
Vol 216 (431-439) ◽  
pp. 221-263 ◽  
Keyword(s):  
Deep Water ◽  
Digestive Enzymes ◽  
Stomach Contents ◽  
Structure And Function ◽  
The Other ◽  
Ciliary Activity ◽  
Crystalline Style ◽  
Food Particles ◽  
The Many ◽  
And Function

Previous work on the structure and function of the alimentary system in the Lamellibranchs (Yonge (1923, 1925, 1926a, 1926b)) showed that the many peculiarities which they exhibit appear to be correlated with the highly developed ciliary feeding mechanisms on the gills and palps, as a result of the action of which only the smallest particles are passed into the œsophagus and stomach. This latter organ is concerned chiefly with sorting the particles, the larger ones being passed directly into the mid-gut and the smaller ones entering the ducts of the digestive diverticula (“liver” or “hepatopancreas”), where they are digested intracellularly. The food is largely of a vegetable nature and the digestive processes are concerned especially with the disposal of carbohydrates. There are present, free in the lumen of the gut, in the epithelium and in the surrounding tissues, great numbers of phagocytes which actively ingest food particles. Their presence, also, appears to be correlated with the finely divided nature of the food and the fact that, but for the digestive action of these phagocytes, particles of food, unless sufficiently fine to enter the ducts of the digestive diverticula, can only be digested if composed of starch or glycogen. The only extracellular digestive enzymes in the gut of the Lamellibranchs, namely, those set free by the dissolution in the stomach of the head of the crystalline style, act exclusively on these two carbohydrates. Owing to their deep water habitat, the Septibranchs have been little studied, but Pelseneer (1891,1911) and Plate (1897) have reported, on the evidence of the stomach contents, that they are carnivorous, while all investigators who have worked upon them have shown that in structure both the food collecting and digestive organs of the Septibranchs are quite distinct from those of the other Lamellibranchs. Gills are absent, their place being taken by the muscular septum, the labial palps are very small and the gut is provided with a muscular coating of a thickness unknown in the other Lamellibranchs, where the finely divided food is carried through the gut exclusively by ciliary activity, and so muscle for peristalsis is unnecessary.

The Gut Microbiome in Neurodegenerative Disorders

2020 ◽  
Author(s):  
Lindsay A. Euers ◽  
Eamon M. M. Quigley
Keyword(s):  
Nervous System ◽  
Neurodegenerative Disorders ◽  
Gut Microbiome ◽  
Brain Structure ◽  
Structure And Function ◽  
Sufficient Evidence ◽  
Brain Structure And Function ◽  
The Many ◽  
And Function ◽  
The Impact

For some time, the concept of the gut-brain axis has served as a useful paradigm to explain the many interactions between the “big brain” (the central nervous system [CNS]) and the “little brain” (the enteric nervous system). Recently, the gut microbiome has been added to the equation and the proposition that gut microbes could influence brain structure and function and vice versa has emerged. Research in this field has been facilitated by dramatic progress in technologies that permit the delineation of the microbial constituents of the gut and their function in health and disease. Studies in a variety of animal models have amply supported the concept of a microbiota-gut-brain-axis and demonstrated that interventions that modulate the microbiome can influence animal behavior and CNS physiology. Understandably, studies of the impact of the microbiome on human brain structure and function are less numerous, but sufficient evidence does exist to indicate that this axis is operating in humans. In terms of neurodegenerative disorders, here again animal data dominate, but a sufficient body of evidence has accumulated to justify further explorations of the role of gut microbiota in Parkinson’s disease and Alzheimer’s disease, as well as in the aging process per se—“inflammaging.” Many confounding factors complicate the interpretation of human studies of the microbiome, and large, longitudinal studies that attempt to account for such confounders are needed. A number of interventions can be entertained—most notably, diet, probiotics, and prebiotics. To date, studies of any such interventions in neurodegenerative disease in humans are scanty.

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