Palaeobiological inferences based on long bone epiphyseal and diaphyseal structure - the forelimb of xenarthrans (Mammalia)

Mapping Intimacies ◽

10.1101/318121 ◽

2018 ◽

Cited By ~ 1

Author(s):

Eli Amson ◽

John A Nyakatura

Keyword(s):

Bone Structure ◽

Phylogenetic Signal ◽

Great Accuracy ◽

Long Bone ◽

Comparative Approach ◽

High Resolution Computed Tomography ◽

3D Architecture ◽

Bone Trabeculae ◽

Close Relatives ◽

Ground Sloths

ABSTRACTTrabecular architecture (i.e., the main orientation of the bone trabeculae, their number, mean thickness, spacing, etc.) has been shown experimentally to adapt with great accuracy and sensitivity to the loadings applied to the bone during life. However, the potential of trabecular parameters used as a proxy for the mechanical environment of an organism’s organ to help reconstruct the lifestyle of extinct taxa has only recently started to be exploited. Furthermore, these parameters are rarely combined to the long-used mid-diaphyseal parameters to inform such reconstructions. Here we investigate xenarthrans, for which functional and ecological reconstructions of extinct forms are particularly important in order to improve our macroevolutionary understanding of their main constitutive clades, i.e., the Tardigrada (sloths), Vermilingua (anteaters), and Cingulata (armadillos and extinct close relatives). The lifestyles of modern xenarthrans can be classified as fully terrestrial and highly fossorial (armadillos), arboreal (partly to fully) and hook-and-pull digging (anteaters), or suspensory (fully arboreal) and non-fossorial (sloths). The degree of arboreality and fossoriality of some extinct forms, “ground sloths” in particular, is highly debated. We used high-resolution computed tomography to compare the epiphyseal 3D architecture and mid-diaphyseal structure of the forelimb bones of extant and extinct xenarthrans. The comparative approach employed aims at inferring the most probable lifestyle of extinct taxa, using phylogenetically informed discriminant analyses. Several challenges preventing the attribution of one of the extant xenarthran lifestyles to the sampled extinct sloths were identified. Differing from that of the larger “ground sloths”, the bone structure of the small-sized Hapalops (Miocene of Argentina), however, was found as significantly more similar to that of extant sloths, even when accounting for the phylogenetic signal.

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The degree and pattern of phylogenetic signal in primate long-bone structure

Journal of Human Evolution ◽

10.1016/j.jhevol.2007.08.008 ◽

2008 ◽

Vol 54 (3) ◽

pp. 309-322 ◽

Cited By ~ 34

Author(s):

Matthew C. O'Neill ◽

Seth D. Dobson

Keyword(s):

Bone Structure ◽

Phylogenetic Signal ◽

Long Bone ◽

Long Bone Structure

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Nesting strategy shapes territorial aggression but not testosterone: a comparative approach in female and male birds

10.1101/2020.12.19.423623 ◽

2020 ◽

Author(s):

SE Lipshutz ◽

KA Rosvall

Keyword(s):

Tree Swallow ◽

Comparative Approach ◽

Female Competition ◽

American Robin ◽

Territorial Aggression ◽

Physical Attack ◽

Cavity Nesting ◽

Comparative Framework ◽

Underlying Mechanisms ◽

Close Relatives

Our understanding of the proximate and ultimate mechanisms shaping competitive phenotypes primarily stems from research on male-male competition for mates, even though female-female competition is also widespread. Obligate secondary cavity-nesting has evolved repeatedly across avian lineages, providing a useful comparative context to explore how competition over limited nest cavities shapes aggression and its underlying mechanisms across species. Although evidence from one or another cavity-nesting species suggests that territorial aggression is adaptive in both females and males, this has not yet been tested in a comparative framework. We tested the hypothesis that cavity-nesting generates more robust territorial aggression, in comparison to close relatives with less restrictive nesting strategies. Our focal species were two obligate secondary cavity-nesting species and two related species with more flexible nesting strategies in the same avian family: tree swallow (Tachycineta bicolor) vs. barn swallow (Hirundo rustica); Eastern bluebird (Sialia sialis) vs. American robin (Turdus migratorius). We assayed conspecific territorial aggression, and found that cavity-nesting species physically attacked a simulated intruder more often than their close relatives. This pattern held for both females and males. Because territorial aggression is often associated with elevated testosterone, we also hypothesized that cavity-nesting species would exhibit higher testosterone levels in circulation. However, cavity-nesting species did not have higher testosterone in circulation for either sex, despite some correlative evidence that testosterone is associated with higher rates of physical attack in female tree swallows. Our focus on a competitive context that is relevant to both sexes – competition over essential breeding resources – provides a useful comparative framework for co-consideration of proximate and ultimate drivers of reproductive competition in females and males.

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The ontogeny of trilobite segmentation: a comparative approach

Paleobiology ◽

10.1666/06017.1 ◽

2006 ◽

Vol 32 (4) ◽

pp. 602-627 ◽

Cited By ~ 93

Author(s):

Nigel C. Hughes ◽

Alessandro Minelli ◽

Giuseppe Fusco

Keyword(s):

Direct Development ◽

Comparative Approach ◽

Phase Boundaries ◽

Free Living ◽

Ancestral Condition ◽

Morphological Transitions ◽

Posterior Trunk ◽

Close Relatives ◽

Number Of Segments ◽

Trunk Segments

Ontogenetic stages of trilobites have traditionally been recognized on the basis of the development of exoskeletal segmentation. The established protaspid, meraspid, and holaspid phases relate specifically to the development of articulated joints between exoskeletal elements. Transitions between these phases were marked by the first and last appearances of new trunk segment articulations. Here we propose an additional and complementary ontogenetic scheme based on the generation of new trunk segments. It includes an anamorphic phase during which new trunk segments appeared, and an epimorphic phase during which the number of segments in the trunk remained constant. In some trilobites an ontogenetic boundary can also be recognized at the first appearance of morphologically distinct posterior trunk segments. Comparison of the phase boundaries of these different aspects of segment ontogeny highlights rich variation in the segmentation process among Trilobita. Cases in which the onset of the holaspid phase preceded onset of the epimorphic phase are here termed protarthrous, synchronous onset of both phases is termed synarthromeric, and onset of the epimorphic phase before onset of the holaspid phase is termed protomeric. Although these conditions varied among close relatives and perhaps even intraspecifically in some cases, particular conditions may have been prevalent within some clades.Trilobites displayed hemianamorphic development that was accomplished over an extended series of juvenile and mature free-living instars. Although developmental schedules varied markedly among species, morphological transitions during trilobite development were generally regular, limited in scope, and extended over a large number of instars when compared with those of many living arthropods. Hemianamorphic, direct development with modest change between instars is also seen among basal members of the Crustacea, basal myriapods, pycnogonids, and in some fossil chelicerates. This mode may represent the ancestral condition of euarthropod development.

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Assessment of joint and bone structure in PsA patients: Using high-resolution computed tomography

10.1093/med/9780198737582.003.0019 ◽

2018 ◽

Author(s):

Camille Figueiredo ◽

Georg Schett

Keyword(s):

Computed Tomography ◽

High Resolution ◽

Bone Structure ◽

Distinct Pattern ◽

Bone Architecture ◽

Joint Disease ◽

High Resolution Computed Tomography ◽

Bone Erosions ◽

Bone Changes ◽

Clinical Arthritis

Psoriatic arthritis (PsA) is associated with a distinct pattern of bone pathology, which influences the clinical picture of the disease. High-resolution computed tomography (CT) has contributed to understanding structural bone changes in PsA. Periarticular bone erosions in PsA are characterized by periosteal responses around the cortical break, distinguishing them from bone erosions in rheumatoid arthritis. Furthermore, a large number of enthesophytes can be found in CT studies of joints of PsA patients and in psoriasis patients without clinical arthritis. This latter observation supports the idea that articular changes start in psoriasis before joint disease commences. Moreover, enthesophytes are not influenced by methotrexate treatment and tumour necrosis factor inhibition. Finally, studies of systemic bone loss by high-resolution CT revealed significant alterations of the bone architecture in PsA but not in patients with skin disease only. In summary, CT has made valuable contributions in understanding the structural bone changes in PsA.

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Analysis of short-term treatment with the phosphodiesterase type 5 inhibitor tadalafil on long bone development in young rats

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00130.2018 ◽

2018 ◽

Vol 315 (4) ◽

pp. E446-E453 ◽

Cited By ~ 4

Author(s):

Luqiang Wang ◽

Haoruo Jia ◽

Robert J. Tower ◽

Michael A. Levine ◽

Ling Qin

Keyword(s):

Growth Plate ◽

Time Course ◽

Bone Growth ◽

Bone Structure ◽

Primary Cultures ◽

Long Bone ◽

Short Term ◽

Short Term Treatment ◽

Bone Properties ◽

Phosphodiesterase Type 5 Inhibitor

Cyclic GMP (cGMP) is an important intracellular regulator of endochondral bone growth and skeletal remodeling. Tadalafil, an inhibitor of the phosphodiesterase (PDE) type 5 (PDE5) that specifically hydrolyzes cGMP, is increasingly used to treat children with pulmonary arterial hypertension (PAH), but the effect of tadalafil on bone growth and strength has not been previously investigated. In this study, we first analyzed the expression of transcripts encoding PDEs in primary cultures of chondrocytes from newborn rat epiphyses. We detected robust expression of PDE5 as the major phosphodiesterase hydrolyzing cGMP. Time-course experiments showed that C-type natriuretic peptide increased intracellular levels of cGMP in primary chondrocytes with a peak at 2 min, and in the presence of tadalafil the peak level of intracellular cGMP was 37% greater ( P < 0.01) and the decline was significantly attenuated. Next, we treated 1-mo-old Sprague Dawley rats with vehicle or tadalafil for 3 wk. Although 10 mg·kg−1·day−1 tadalafil led to a significant 52% ( P < 0.01) increase in tissue levels of cGMP and a 9% reduction ( P < 0.01) in bodyweight gain, it did not alter long bone length, cortical or trabecular bone properties, and histological features. In conclusion, our results indicate that PDE5 is highly expressed in growth plate chondrocytes, and short-term tadalafil treatment of growing rats at doses comparable to those used in children with PAH has neither obvious beneficial effect on long bone growth nor any observable adverse effect on growth plate structure and trabecular and cortical bone structure.

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Do Hind Wing Eyespots of Caligo Butterflies Function in Both Mating Behavior and Antipredator Defense? (Lepidoptera, Nymphalidae)

Annals of the Entomological Society of America ◽

10.1093/aesa/saaa050 ◽

2020 ◽

Author(s):

Logan D Crees ◽

Phil DeVries ◽

Carla M Penz

Keyword(s):

Hind Wing ◽

Phylogenetic Signal ◽

Positive Association ◽

Sympatric Species ◽

Color Pattern ◽

Visual Signal ◽

Antipredator Defense ◽

Predator Prey ◽

Close Relatives ◽

Relationship Of

Abstract In general, butterfly ventral hind wing eyespots are considered to play a role in predator–prey interactions. These eyespots are prominent wing pattern elements in Brassolini butterflies, and they vary in size, position, and number across taxa. Female Caligo Hübner, 1819 (Lepidoptera, Nymphalidae) appear to use the large eyespots of lekking males as a mate-locating cue, but female Opsiphanes Doubleday, 1849 (Lepidoptera, Nymphalidae) do not because males patrol to find mates. These behaviors led us to predict that male Caligo should have larger eyespots than females, but eyespot size would not differ between sexes in Opsiphanes. Our analyses supported these predictions. As displacement of the eyespots to the center of the wing might make them more conspicuous, we asked if eyespot position and size covaried across the Brassolini phylogeny. While we found a positive association between position and size, the relationship of these two variables contained significant phylogenetic signal. Two Brassolini species show strong sexual dimorphism where females converge on the color pattern of sympatric species of Caligo. Their ventral hind wing eyespots are much larger than those of close relatives, approximating those of Caligo, and further reinforcing the importance of ventral hind wing eyespots as a visual signal in this group of butterflies. Importantly, our results suggest that, in addition to antipredation defense, ventral hind wing eyespots can function in mating activities, and consequently they might be evolving under both natural and sexual selection in Caligo butterflies.

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Habitats of native and exotic plants in Colorado shortgrass steppe: a comparative approach

Canadian Journal of Botany ◽

10.1139/b98-036 ◽

1998 ◽

Vol 76 (4) ◽

pp. 664-672 ◽

Cited By ~ 10

Author(s):

Peter M Kotanen ◽

Joy Bergelson ◽

Donald L Hazlett

Keyword(s):

Geographic Origin ◽

Habitat Characteristics ◽

Comparative Approach ◽

Riparian Zones ◽

Common Ancestry ◽

Central Plains ◽

Invading Species ◽

Close Relatives ◽

Grassland Habitats ◽

The Relationship

Invading species often are close relatives, and therefore share many characteristics as a consequence of their common ancestry. This tends to confound studies of invasions, since many irrelevant characteristics are likely to be correlated with a species' geographic origin (alien or native). We address this problem by using phylogenetically independent comparisons to investigate the habitat characteristics of plants of the Central Plains Experimental Range (Colorado, U.S.A.). We initially show that exotic species are more likely than natives to occur in riparian zones, roadsides, and disturbed sites, and less likely to occur in grassland. The relationship between exotic origins and disturbed sites disappears when phylogenetic dependence is removed from the analyses; in contrast, the other associations persist following phylogenetic detrending, indicating that aliens and their native relatives consistently differ in their ability to exploit riparian, roadside, and grassland habitats. Our results indicate that disturbed sites currently are dominated by only a few groups of related exotic ruderals, while the ability to exploit roadsides and riparian zones has been and may continue to be important for the success of many taxa of invaders.Key words: biological invasions, comparative methods, disturbance, grasslands, phylogeny.

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Fabrication of NiTi Shape Memory Alloys with Graded Porosity to Imitate Human Long-bone Structure

Journal of Bionic Engineering ◽

10.1016/s1672-6529(14)60147-5 ◽

2015 ◽

Vol 12 (4) ◽

pp. 575-582 ◽

Cited By ~ 14

Author(s):

Dan Zhou ◽

Yan Gao ◽

Ming Lai ◽

Hao Li ◽

Bin Yuan ◽

...

Keyword(s):

Shape Memory Alloys ◽

Shape Memory ◽

Bone Structure ◽

Long Bone ◽

Niti Shape Memory Alloys ◽

Long Bone Structure

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Limitations in Use of Elastic Stable Intramedullary Nailing (ESIN) in Children with Disorders of Bone Mineralization

Ortopedia Traumatologia Rehabilitacja ◽

10.5604/01.3001.0014.1154 ◽

2020 ◽

Vol 22 (2) ◽

pp. 77-83

Author(s):

Artur Oberc ◽

Jerzy Sułko

Keyword(s):

Bone Structure ◽

Bone Fractures ◽

Bone Mineralization ◽

Cartilage Damage ◽

Long Bone ◽

Mechanical Resistance ◽

Long Bone Fractures ◽

Fractures In Children ◽

Satisfactory Outcome ◽

Pin Fixation

Background. Elastic intramedullary nails (ESIN) have been the treatment of choice in many long bone fractures in children for more than 20 years. The introduction of ESIN has drastically reduced tissue traumatization during fracture fixation procedures and decreased the risk of growth cartilage damage, as well as allowing for preservation of the natural biology of closed fracture healing. The objective of the present report is to draw attention to a small group of patients with bone mineralization disorders, who consequently demonstrate decreased mechanical resistance of the skeletal system, in whom indications for using ESIN fixation are limited. Material and methods. The study group consisted of 6 patients who met the criteria for using ESIN fixation, but did not demonstrate a satisfactory outcome. The inclusion criteria included age below 18 years, appropriate ESIN nail insertion technique with correct calculation of nail diameter (2/5 of the medullary canal diameter), body mass < 50 kg and achieving appropriate prebending that is the prerequisite of three-point intramedullary support. The patients’ medical records and radiographs were analyzed and they were invited for clinical and radiological follow-up examinations. Results. All six patients demonstrated a gradually increasing bending deformity of the long bone axis. Additionally, in three patients, there was intrusion of terminal parts of the nails into the bone. In one patient with bone fibrous dysplasia, the proximal epiphysis was perforated by the flattened ends of the nails. In all patients, the removal of the ESIN fixation was followed by single or double-level corrective osteotomies and Rush pin fixation. Conclusion. In cases of long bone fractures in children with metabolic bone disorders in whom the bone structure is weakened and the bones themselves are easily deformed, more rigid intramedullary fixation with Rush or Fassier-Duval type nails as primary osteosynthesis should be considered.

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