Results 81 to 90 of about 229,879 (262)

Early stages of tooth development in the harbor porpoise Phocoena phocoena

open access: yesThe Anatomical Record, EarlyView.
Abstract Here we describe the stages of tooth development in toothed whales on the basis of the harbor porpoise (Phocoena phocoena). The aim of the study was to find out whether these stages are identical to those of other mammals analyzed so far although toothed whales are homodont and monophyodont.
Lasse M. Mathes   +2 more
wiley   +1 more source

Oldest well‐preserved euprimate petrosal, from the early Eocene of India (Vastan Lignite Mine, Gujarat)

open access: yesThe Anatomical Record, EarlyView.
Abstract An exquisitely preserved, isolated partial petrosal with associated fragmentary stapes is described from the Vastan Lignite Mine (Gujarat, India), dated to the early Eocene (~54.5 Ma). Several anatomical traits (e.g., large petrosal plate; posterolateral entry of the internal carotid artery to the tympanic cavity; bony tubes surrounding the ...
Mary T. Silcox   +8 more
wiley   +1 more source

Twin pregnancies and the limits of the energetics of gestation and growth hypothesis

open access: yesThe Anatomical Record, EarlyView.
Abstract The “Energetics of Gestation and Growth” (EGG) hypothesis proposes that human birth timing and the associated secondary altriciality of human newborns is determined by limits in maternal metabolic capacity. According to this model, labor is triggered when the increasing fetal energy requirements exceed the expectant mother's maximum sustained ...
Cédric Cordey   +2 more
wiley   +1 more source

The 9+ month marathon: How pregnancy may have shaped human endurance capacities

open access: yesThe Anatomical Record, EarlyView.
Abstract Anthropology has long considered the evolution of our uniquely human endurance capacities to be the result of selection upon anatomical and physiological features imposed by the demands of thermoregulation and resource acquisition, particularly during the demands of persistence hunting. Research has focused on the anatomical changes present in
Cara Ocobock
wiley   +1 more source

The fossil record stays silent: Confusions and conundrums for hominin pelvis evolution

open access: yesThe Anatomical Record, EarlyView.
Abstract The evolution of the hominin pelvis is commonly modeled as a series of stages driven largely by the requirements of bipedal locomotion, reproduction, thermoregulation, and pelvic floor muscular support. These patterns are complicated by variation in canal dimensions in relationship with different changes in overall pelvic breadths. To quantify
Helen K. Kurki, Cara M. Wall‐Scheffler
wiley   +1 more source

Lineage tracing studies suggest that the placenta is not a de novo source of hematopoietic stem cells.

open access: yesPLoS Biology
Definitive hematopoietic stem and progenitor cells (HSPCs) arise from a small number of hemogenic endothelial cells (HECs) within the developing embryo. Understanding the origin and ontogeny of HSPCs is of considerable interest and potential therapeutic ...
Xiaowen Chen   +13 more
doaj   +1 more source

The mechanism of labor in nonhuman primates: A look inside

open access: yesThe Anatomical Record, EarlyView.
Abstract While in humans, the flexed position of the fetus and its rotating course down the birth canal are well documented, in other primates the mechanism of labor is unknown. Despite the lack of comparative data, it is commonly assumed that the human obstetric mechanism is unique, and anthropologists have disputed when and why the transition to the ...
Melissa K. Stoller
wiley   +1 more source

Plastic, microplastic, and the inconsistency of human thought

open access: yesFrontiers in Public Health, 2023
Antonio Ragusa   +4 more
doaj   +1 more source

Mesenchymal stem cell derived extracellular vesicles reverses neural aging via OSKM modulation

open access: yesCell Communication and Signaling
Background Intravenously infused human placenta-derived mesenchymal stem cells enhance overall function and exhibit therapeutic potential even with minimal engraftment or tissue replacement, with substances released from human placenta-derived ...
Chul Kim   +10 more
doaj   +1 more source

Developmental differences in cortical bone structure in chimpanzee and human femora reflect early locomotor independence in humans

open access: yesThe Anatomical Record, EarlyView.
Abstract The cortical bone structure of long bone diaphyses changes throughout growth via skeletal modeling and has important implications for bone strength and structural integrity. Ontogenetic trends in diaphyseal structure have been identified in both chimpanzees and humans but it is not yet clear how these trends compare given notable differences ...
Karen R. Swan   +3 more
wiley   +1 more source

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