scholarly journals Ontogenetic scaling of hydrostatic skeletons: geometric, static stress and dynamic stress scaling of the earthworm lumbricus terrestris

1998 ◽  
Vol 201 (12) ◽  
pp. 1871-1883 ◽  
Author(s):  
KJ Quillin
Keyword(s):  
Body Size ◽  
Body Wall ◽  
Dynamic Stress ◽  
Lumbricus Terrestris ◽  
Static Stress ◽  
The Body ◽  
Cross Sectional ◽  
Dynamic Stresses ◽  
Form And Function ◽  
And Function

Soft-bodied organisms with hydrostatic skeletons range enormously in body size, both during the growth of individuals and in the comparison of species. Therefore, body size is an important consideration in an examination of the mechanical function of hydrostatic skeletons. The scaling of hydrostatic skeletons cannot be inferred from existing studies of the lever-like skeletons of vertebrates and arthropods because the two skeleton types function by different mechanisms. Hydrostats are constructed of an extensible body wall in tension surrounding a fluid or deformable tissue under compression. It is the pressurized internal fluid (rather than the rigid levers of vertebrates and arthropods) that enables the maintenance of posture, antagonism of muscles and transfer of muscle forces to the environment. The objectives of the present study were (1) to define the geometric, static stress and dynamic stress similarity scaling hypotheses for hydrostatic skeletons on the basis of their generalized form and function, and (2) to apply these similarity hypotheses in a study of the ontogenetic scaling of earthworms, Lumbricus terrestris, to determine which parameters of skeletal function are conserved or changed as a function of body mass during growth (from 0.01 to 8 g). Morphometric measurements on anesthetized earthworms revealed that the earthworms grew isometrically; the external proportions and number of segments were constant as a function of body size. Calculations of static stresses (forces per cross-sectional area in the body wall) during rest and dynamic stresses during peristaltic crawling (calculated from measurements of internal pressure and body wall geometry) revealed that the earthworms also maintained static and dynamic stress similarity, despite a slight increase in body wall thickness in segment 50 (but not in segment 15). In summary, the hydrostatic skeletons of earthworms differ fundamentally from the rigid, lever-like skeletons of their terrestrial counterparts in their ability to grow isometrically while maintaining similarity in both static and dynamic stresses.

Mechanobiology and Adaptive Plasticity (MAP) Theory as a Potential Confounding Factor in Predicting Musculoskeletal Foot Function

2021 ◽  
Author(s):  
Greg Quinn
Keyword(s):  
Physical Nature ◽  
Theoretical Models ◽  
The Body ◽  
Adaptive Plasticity ◽  
Form And Function ◽  
Complex Processes ◽  
Kinetic Information ◽  
Foot Function ◽  
Clinical Variation ◽  
And Function

There are many theoretical models that attempt to accurately and consistently link kinematic and kinetic information to musculoskeletal pain and deformity of the foot. Biomechanical theory of the foot lacks a consensual model: clinicians are enticed to draw from numerous paradigms, each having different levels of supportive evidence and contrasting methods of evaluation, in order to engage in clinical deduction and treatment planning. Contriving to find a link between form and function lies at the heart of most of these competing theories and the physical nature of the discipline has prompted an engineering approach. Physics is of great importance in biology and helps us to model the forces that the foot has to deal with in order for it to work effectively. However, the tissues of the body have complex processes that are in place to protect them and they are variable between individuals. Research is uncovering why these differences exist and how these processes are governed. The emerging explanations for adaptability of foot structure and musculoskeletal homeostasis offer new insights on how clinical variation in outcomes and treatment effects might arise. These biological processes underlie how variation in the performance and utilisation of common traits, even within apparently similar sub-groups, make anatomical distinction less meaningful and are likely to undermine the justification of a 'foot type'. Furthermore, mechanobiology introduces a probabilistic element to morphology based on genetic and epigenetic factors.

scholarly journals Pattern of Adiponectin, Osteocalcin, Irisin, FGF-21, and MCP-1 According to the Body Size Phenotype: Could They Be Markers of Metabolic Health in Mexican-Mestizo Middle-Aged Women?

Metabolites ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 771
Author(s):  
Lourdes Balcázar-Hernandez ◽  
Lourdes Basurto ◽  
Leticia Manuel-Apolinar ◽  
Sara Vega-García ◽  
Norma Basurto-Acevedo ◽  
...  
Keyword(s):  
Body Size ◽  
Cross Sectional Study ◽  
Normal Weight ◽  
The Body ◽  
Metabolic Phenotype ◽  
Obese Women ◽  
Middle Aged ◽  
Cross Sectional ◽  
Metabolically Healthy Obese ◽  
Metabolically Healthy

Variations in levels of some adipokines, myokines, osteokines, hepatokines and inflammatory cytokines contribute to abnormal glucose and lipid metabolism. The aim of this study was to determine the pattern of adiponectin, osteocalcin (OCN), irisin, FGF-21, and MCP-1 according to the body size phenotype of middle-aged women, and their associations with BMI, visceral adipose tissue (VAT), and HOMA-IR. A cross-sectional study in 265 women aged from 40 to 65 years was performed. The biochemical characteristics were evaluated in metabolically healthy normal weight, metabolically unhealthy normal weight, metabolically healthy obese, and metabolically unhealthy obese women. There was an association of OCN with BMI (r = −0.107; p = 0.047); adiponectin with BMI (r = −0.217; p = 0.001), insulin (r = −0.415; p = 0.0001), HOMA-IR (r = −0.429; p = 0.0001), and VAT (r = −0.134; p = 0.025); irisin with BMI (r = 0.604; p = 0.001), insulin (r = 0.446; p = 0.0001), HOMA-IR (r = 0.452; p = 0.0001), and VAT (r = 0.645; p = 0.0001); FGF−21 with insulin (r = −0.337; p= 0.030) and HOMA-IR (r = −0.341; p = 0.03); and MCP-1 with BMI (r = 0.481; p = 0.0001), VAT (r = 0.497; p = 0.001), insulin (r = 0.298; p= 0.001), and HOMA-IR (r = 0.255; p = 0.004). A multivariate analysis showed that an elevation of OCN (OR 1.4 (95%CI 1.06–1.81)) and a reduction of adiponectin (OR 0.9 (0.84–0.96)) were associated factors for a metabolic unhealthy phenotype in normal weight participants. Likewise, higher irisin (OR 1.007 (1.003–1.011)) and MCP-1 (1.044 (1.008–1.083)) were risk factors for a metabolic unhealthy phenotype in woman with obesity. OCN, adiponectin, irisin, FGF-21, and MCP-1 are associated with some metabolic parameters such as BMI, HOMA-IR, and VAT, and could be possible biomarkers of an unhealthy metabolic phenotype in middle-aged women.

scholarly journals Interaction patterns on body size and health on Instagram and associated factors in nutrition students: an exploratory study

2021 ◽  
Vol 34 ◽  
Author(s):  
Pabyle Alves FLAUZINO ◽  
Antonio Augusto Ferreira CARIOCA
Keyword(s):  
Body Size ◽  
Associated Factors ◽  
Educational Institution ◽  
Cross Sectional Study ◽  
Female Students ◽  
The Body ◽  
Interaction Patterns ◽  
Cross Sectional ◽  
Main Component ◽  
High Engagement

ABSTRACT Objective To identify interaction patterns on body size and health on Instagram and associated factors in nutrition students. Methods A total of 406 students (78% female) were included in this cross-sectional study. Instagram sociodemographic, academic and interaction data (Instagram time of use, exposure frequency to contents on body size and health, Instagram as a source of information and number of followers) were collected using a self-administered virtual questionnaire. A factor analysis by main component was used to derive the interaction patterns of Instagram as well as regression analyses to test the association of the patterns with the sociodemographic and academic factors. Results Three interaction patterns were observed on body size and health, named: “Fitness Pattern”; “Body Positivity Pattern” and “High Engagement Pattern”. Private Institutions’ Students who are on or have been on a diet and studying in the first semesters were associated with the “Fitness Pattern” (p<0.05). Female students, from public institutions, who changed their weight during the course and whose family’s head had higher education, were associated with the “Body Positivity Pattern” (p<0.05). Female students, younger and on a diet, were associated with the “High engagement Pattern” (p<0.05). Conclusion Gender, type of educational institution and diet practice of nutrition students are the factors that are most associated with different patterns of interaction on body size and health on Instagram.

Memoirs: On the Reproductive Processes of the Earthworm, Lumbricus Terrestris

1925 ◽  
Vol s2-69 (274) ◽  
pp. 245-290
Author(s):  
A. J. GROVE
Keyword(s):  
Body Wall ◽  
Seminal Fluid ◽  
Lumbricus Terrestris ◽  
The Body ◽  
The Other ◽  
Reproductive Processes ◽  
Longitudinal Muscles ◽  
Earthworm Lumbricus

During the sexual congress of L.terrestris, the co-operating worms become attached to one another in a head-to-tail position in such a way that segments 9-11 of one are opposed to the clitellum of the other, and vice versa. At these points the attachment between the worms is an intimate one, assisted by the secretion of the glands associated with the diverticula of the setal pores found in certain segments, and is reinforced by the mutual penetration of the setae into the opposed body-surfaces. There is also a slighter attachment between segment 26 of one and 15 of the other. Each worm is enclosed in a slime-tube composed of mucus secreted from the epidermis. The exchange of seminal fluid is a mutual one. The fluid issues from the apertures of the vasa deferentia in segment 15, and is conducted beneath the slime-tube in pit-like depressions in the seminal grooves, which extend from segment 15 to the clitellum on each side of the body, to the clitellum, where it accumulates in the space between the lateral surfaces of segments 9-11 of one worm and the clitellum of the other. Eventually it becomes aggregated into masses in the groove between segments 9 and 10, and 10 and 11, and passes thence into the spermathecae. The seminal groove and its pit-like depressions are brought into existence by special muscles lying in the lateral blocks of longitudinal muscles of the body-wall.

Body wall: form and function.

2009 ◽  
pp. 147-178 ◽  
Author(s):  
D. L. Luchtel ◽  
I. Deyrup-Olsen
Keyword(s):  
Body Wall ◽  
Form And Function ◽  
And Function

Two new species of montane web-footed salamanders (Plethodontidae: Bolitoglossa) from the Costa Rica-Panamá border region

Zootaxa ◽  
2009 ◽  
Vol 1981 (1) ◽  
pp. 57-68 ◽  
Author(s):  
FEDERICO BOLAÑOS ◽  
DAVID B. WAKE
Keyword(s):  
New Species ◽  
Body Size ◽  
Costa Rica ◽  
Body Wall ◽  
Species Group ◽  
The Body ◽  
Border Region ◽  
Two New Species ◽  
Adult Body ◽  
Salamander Species

Two new species of lungless salamanders (Plethodontidae) are described from high montane habitats of the border region between Costa Rica and Panamá. Bolitoglossa pygmaea and B. robinsoni are distinguished from each other and from other salamander species in this remote area by differences in adult body size, external proportions, foot webbing, tooth counts and/or external coloration. Both new species are assigned to the B. subpalmata species group, subgenus Eladinea. The miniaturized B. pygmaea is remarkable in being extensively depigmented, yet having the peritoneum and stomach area heavily pigmented and visible through the body wall.

scholarly journals The Arginase Activity of the Tissues of the Earthworms Lumbricus Terrestris L., and Eisenia Foetida (Savigny)

1960 ◽  
Vol 37 (4) ◽  
pp. 775-782
Author(s):  
A. E. NEEDHAM
Keyword(s):  
Body Wall ◽  
Lumbricus Terrestris ◽  
Total Activity ◽  
The Body ◽  
Arginase Activity ◽  
Unit Weight ◽  
Eisenia Foetida ◽  
Previous Evidence ◽  
Urea Production ◽  
The Difference

1. The difference in arginase activity between the tissues of Eisenia and those of Lumbricus shows a relationship to the difference in urea output by living worms of the two species under the same dietary régime. 2. In Eisenia the difference in activity between the tissues of fasting and feeding worms is much smaller than in Lumbricus. The specific outputs of urea by living, fasting and feeding worms likewise differ less than in Lumbricus. 3. These facts strengthen previous evidence in favour of a Krebs-Henseleit type of mechanism for urea production in earthworms. 4. In Eisenia the difference in arginase activity between gut and body wall is similar to, but smaller than, that in Lumbricus, and the body wall makes a major contribution to the total activity. 5. The combined concentrations of ammonia-, amino-, and urea-nitrogen initially present in homogenates of the tissues of these worms are proportional to the combined amounts of the three components excreted per unit weight by living worms of the same species and régime. 6. The two species differ in a number of other properties investigated.

scholarly journals A Historical Review of Enzymatic Debridement: Revisited

2019 ◽  
Author(s):  
Brett David W
Keyword(s):  
Wound Care ◽  
Historical Review ◽  
The Body ◽  
Form And Function ◽  
Bacterial Collagenase ◽  
History Of ◽  
Biochemical Research ◽  
The Many ◽  
And Function ◽  
Enzymatic Debridement

The following is an update to a book entitled, “A Historical Review of Enzymatic Debridement: Revisited”, which I wrote in 2003. Since its publication, while the relevant clinical evidence has remained consistent, the amount of biochemical research and knowledge gained has been impressive. In the first chapter a sampling of the typical topical enzymatic debriding agents that have been used in wound care are reviewed and interestingly enough only one remains on the market. The FDA has removed all others from the marketplace and an explanation is provided in chapter one along with descriptions of the use and mode of action (MoA) of these agents. Chapter two is a review of the many different types of collagen found in the body, including their structure, form, and function as so much additional insight into this molecule has been gained since 2003. In chapter three we see an account depicting the many advances in understanding matrix metalloproteinases (MMPs) reviewed in detail. Form, function, tissue orientation and preferred substrates are addressed. Finally, in chapter four we see the history of the MoA of MMPs as compared to bacterial collagenase starting in the early ‘80s to the time of this current publication. In addition we see the level of complexity of bacterial collagenases compared to MMPs, helping us to better understand why bacterial collagenase is much more efficient at removing necrotic tissue from wounds than are our own (endogenous) MMPs. I hope the reader finds this review useful from an academic standpoint, but more importantly from a clinical framework helping to understand the role of these types of therapies in wound care.

Kinematic scaling of locomotion by hydrostatic animals: ontogeny of peristaltic crawling by the earthworm lumbricus terrestris

1999 ◽  
Vol 202 (6) ◽  
pp. 661-674 ◽  
Author(s):  
K.J. Quillin
Keyword(s):  
Body Mass ◽  
Body Wall ◽  
Deformable Body ◽  
Lumbricus Terrestris ◽  
The Body ◽  
Duty Factor ◽  
Body Segments ◽  
The Relationship ◽  
Dynamic Shape ◽  
Earthworm Lumbricus

This study examined the relationship between ontogenetic increase in body size and the kinematics of peristaltic locomotion by the earthworm Lumbricus terrestris, a soft-bodied organism supported by a hydrostatic skeleton. Whereas the motions of most vertebrates and arthropods are based primarily on the changes in the joint angles between rigid body segments, the motions of soft-bodied organisms with hydrostatic skeletons are based primarily on the changes in dimensions of the deformable body segments themselves. The overall kinematics of peristaltic crawling and the dynamic shape changes of individual earthworm segments were measured for individuals ranging in body mass (mb) by almost three orders of magnitude (0.012-8.5 g). Preferred crawling speed varied both within and among individuals: earthworms crawled faster primarily by taking longer strides, but also by taking more strides per unit time and by decreasing duty factor. On average, larger worms crawled at a greater absolute speed than smaller worms (U p2finity mb0.33) and did so by taking slightly longer strides (l p2finity mb0.41, where l is stride length) than expected by geometric similarity, using slightly lower stride frequencies (f p2finity mb-0.07) and the same duty factor (df p2finity mb-0.03). Circumferential and longitudinal body wall strains were generally independent of body mass, while strain rates changed little as a function of body mass. Given the extent of kinematic variation within and among earthworms, the crawling of earthworms of different sizes can be considered to show kinematic similarity when the kinematic variables are normalized by body length. Since the motions of peristaltic organisms are based primarily on changes in the dimensions of the deformable body wall, the scaling of the material properties of the body wall is probably an especially important determinant of the scaling of the kinematics of locomotion.

Sign in / Sign up

Export Citation Format

Share Document