Cranial Shape and Diet Variation inMyotisSpecies (Chiroptera: Vespertilionidae): Testing the Relationship between Form and Function

2016 ◽  
Vol 18 (1) ◽  
pp. 163-180 ◽  
Author(s):  
Sandra Milena Ospina-Garcés ◽  
Efraín De Luna ◽  
L. Gerardo Herrera M. ◽  
José Juan Flores-Martínez
2014 ◽  
Author(s):  
Brian P Kraatz ◽  
Nicholas Bumacod ◽  
Emma Sherratt ◽  
Mathew J Wedel

The mammalian order Lagomorpha has been the subject of many morphometric studies aimed at understanding the relationship between form and function as it relates to locomotion, primarily in postcranial morphology. The leporid cranial skeleton, however, may also reveal information about their ecology, particularly locomotion and vision. Here we investigate the relationship between cranial shape and the degree of facial tilt with locomotion (cursoriality, saltation, and burrowing) within crown leporids. Our results suggest that facial tilt is more pronounced in cursors and saltators compared to generalists. However cranial shape does not differ significantly among these locomotor groups, nor does it differ significantly between species that burrow and those that do not.


Author(s):  
Aurélien Lowie ◽  
Barbara De Kegel ◽  
Mark Wilkinson ◽  
John Measey ◽  
James C. O'Reilly ◽  
...  

Caecilians are elongate, limbless, and annulated amphibians that, with the exception of one aquatic family, all have an at least partly fossorial lifestyle. It has been suggested that caecilian evolution resulted in sturdy and compact skulls with fused bones and tight sutures, as an adaptation to their head-first burrowing habits. However, although their cranial osteology is well described, relationships between form and function remain poorly understood. In the present study, we explored the relationship between cranial shape and in vivo burrowing forces. Using µCT-data, we performed three-dimensional geometric morphometrics to explore whether cranial and mandibular shapes reflected patterns that might be associated with maximal push forces. The results highlight important differences in maximal push forces, with the aquatic Typhlonectes producing a lower force for a given size compared to other species. Despite substantial differences in head morphology across species, no relation between overall skull shape and push force could be detected. Although a strong phylogenetic signal may partly obscure the results, our conclusions confirm previous studies using biomechanical models and suggest that differences in the degree of fossoriality do not appear to be driving the evolution of head shape.


2014 ◽  
Author(s):  
Brian P Kraatz ◽  
Nicholas Bumacod ◽  
Emma Sherratt ◽  
Mathew J Wedel

The mammalian order Lagomorpha has been the subject of many morphometric studies aimed at understanding the relationship between form and function as it relates to locomotion, primarily in postcranial morphology. The leporid cranial skeleton, however, may also reveal information about their ecology, particularly locomotion and vision. Here we investigate the relationship between cranial shape and the degree of facial tilt with locomotion (cursoriality, saltation, and burrowing) within crown leporids. Our results suggest that facial tilt is more pronounced in cursors and saltators compared to generalists. However cranial shape does not differ significantly among these locomotor groups, nor does it differ significantly between species that burrow and those that do not.


Author(s):  
Patricia G. Arscott ◽  
Gil Lee ◽  
Victor A. Bloomfield ◽  
D. Fennell Evans

STM is one of the most promising techniques available for visualizing the fine details of biomolecular structure. It has been used to map the surface topography of inorganic materials in atomic dimensions, and thus has the resolving power not only to determine the conformation of small molecules but to distinguish site-specific features within a molecule. That level of detail is of critical importance in understanding the relationship between form and function in biological systems. The size, shape, and accessibility of molecular structures can be determined much more accurately by STM than by electron microscopy since no staining, shadowing or labeling with heavy metals is required, and there is no exposure to damaging radiation by electrons. Crystallography and most other physical techniques do not give information about individual molecules.We have obtained striking images of DNA and RNA, using calf thymus DNA and two synthetic polynucleotides, poly(dG-me5dC)·poly(dG-me5dC) and poly(rA)·poly(rU).


2000 ◽  
Vol 2 (2) ◽  
pp. 117-131 ◽  
Author(s):  
Kathleen Michael

In the realm of muscle atrophy research, many studies address minute details of molecular function but few examine the effects of atrophy in terms of mobility, strength, endurance, and performance of activities of daily living. The relationship between impairment and functional limitation is the focus of this research review. A wide array of studies constitute this area of inquiry, including investigations as diverse and widely disparate as molecular chemistry and space travel and populations as different as rats, healthy young men, and elderly women. Thirty-four studies were selected based on their fit with the Enabling-Disabling Model. Three paradigms of atrophy and function emerged. Adaptation reflects the plastic nature of muscle when placed under certain conditions, ranging from disuse to high-resistance exercise. Injury/loss describes damage to muscle tissue from ischemia, medications, or reloading or reperfusion trauma. Also in this category is the loss of muscle that is seen with aging. Integrity relates to the muscle’s tendency to protect itself and maintain structural adjacencies and cellular proportions. Based on the 3 muscle research paradigms, the relationship of muscle atrophy to function is portrayed as a bidirectional interaction wherein form and function have an influence on each other by way of physical changes, including those of adaptation, injury/loss, or integrity. A conceptual model is constructed to reflect this relationship.


2009 ◽  
Vol 32 (1) ◽  
pp. 55-76 ◽  
Author(s):  
Nunzio La Fauci ◽  
Liana Tronci

This paper deals with the complex interaction between form and function in the verb morphosyntax of four Indo-European languages (French, Italian, Ancient Greek and Sanskrit). Beyond the difference in form, auxiliation patterns in French and Italian, and verb inflections in Ancient Greek and Sanskrit correlate, thanks to the agreement for number and person, to the expression of the relationship with the Subject. The different auxiliation patterns (sum and habeo) and the different inflections (middle and active) correlate to different properties of the Subject. In particular, these forms depend on the syntactic opposition between middle and non-middle. The ways of this dependency are regulated and systematic, although they appear fuzzy and chaotic, not only if the four languages are compared to each other, but also if different morphosyntactic combinations, inside the same language, are concerned.


Pragmatics ◽  
1991 ◽  
Vol 1 (4) ◽  
pp. 465-480 ◽  
Author(s):  
Joan A. Argente ◽  
Lluís Payrató

The study of language contact has been traditionally carried out from a structural perspective (synchronic or diachronic), from a sociolinguistic perspective and/or from a rather psychological perspective, centered on the linguistic and communicative competence of the multilingual individual. However, a great number of linguistic and sociolinguistic topics that appear in language contact situations may be productively tackled from a pragmatic viewpoint. This pragmatic perspective takes into account linguistic use in communication contexts and raises, at a different level, questions that deal with the structures and the evolution of the codes in contact. The main aim of this presentation is the analysis of some of the specific problems that arise in given language contact situations from a pragmatic perspective, considering the adaptation processes of the speakers, their particular interactive strategies and the social meaning generated. Understanding pragmatics in its original sense, i.e. as the study of the relationship between linguistic signs and speakers (users of certain resources), these phenomena should be understood as the result of speakers’ adaptation to changing sociocultural circumstances. This adaptation creates a new distribution of the verbal resources (or linguistic economy) of the community and, consequently, modifies its varieties as far as form and function are concerned.


English Today ◽  
2008 ◽  
Vol 24 (3) ◽  
pp. 58-61 ◽  
Author(s):  
Alessia Cogo

ABSTRACTIn this paper I wish to respond to the article published in ET94 by Saraceni while at the same time providing some clarifications concerning the concept of English as a Lingua Franca (henceforth ELF). In his article Saraceni raises three main questions (and a number of related debatable comments which I will quickly deal with in my final remarks) regarding: 1) the nature of ELF and its speakers, 2) the relationship between ELF and the World Englishes (henceforth WE) paradigm, and 3) the distinction between form and function. I will address each of these questions, and in so doing consider a number of notions concerning the ELF research field.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Kevin F. H. Lee ◽  
Cary Soares ◽  
Jean-Claude Béïque

The majority of fast excitatory synaptic transmission in the central nervous system takes place at protrusions along dendrites called spines. Dendritic spines are highly heterogeneous, both morphologically and functionally. Not surprisingly, there has been much speculation and debate on the relationship between spine structure and function. The advent of multi-photon laser-scanning microscopy has greatly improved our ability to investigate the dynamic interplay between spine form and function. Regulated structural changes occur at spines undergoing plasticity, offering a mechanism to account for the well-described correlation between spine size and synapse strength. In turn, spine structure can influence the degree of biochemical and perhaps electrical compartmentalization at individual synapses. Here, we review the relationship between dendritic spine morphology, features of spine compartmentalization and synaptic plasticity. We highlight emerging molecular mechanisms that link structural and functional changes in spines during plasticity, and also consider circumstances that underscore some divergence from a tight structure-function coupling. Because of the intricate influence of spine structure on biochemical and electrical signalling, activity-dependent changes in spine morphology alone may thus contribute to the metaplastic potential of synapses. This possibility asserts a role for structural dynamics in neuronal information storage and aligns well with current computational models.


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