scholarly journals Semper's cells in the insect compound eye: Insights into ocular form and function

2021 ◽  
Author(s):  
Mark A. Charlton-Perkins ◽  
Markus Friedrich ◽  
Tiffany A. Cook
Keyword(s):  
Compound Eye ◽  
Form And Function ◽  
And Function

Form and function in Thylacocephala, Conchyliocarida and Concavicarida (?Crustacea): a problem of interpretation

1985 ◽  
Vol 76 (2-3) ◽  
pp. 391-399 ◽  
Author(s):  
W. D. Ian Rolfe
Keyword(s):  
Compound Eye ◽  
Neutral Buoyancy ◽  
Low Contrast ◽  
Linear Pattern ◽  
Form And Function ◽  
Mode Of Life ◽  
And Function ◽  
Food Substrate

ABSTRACTDifferences in the preservation of Jurassic thylacocephalans and conchyliocarids have given rise to different interpretations of the form of these fossils, and thus their mode of life. When evidence from these two groups is combined with that derived from Palaeozoic concavicarids, it becomes possible to unify the several interpretations of this one group of organisms, the Thylacocephala. The group ranges from at least the Silurian to the Cretaceous.A review is given of how these differences of interpretation have arisen, and some resolution is attempted. If the thylacocephalan “anterior structure” is reinterpreted by analogy with hyperiid amphipods as a paired compound eye occupying most of the surface of the head, it explains its bilobed nature and the position of the stomach within the structure, but it raises the difficulty of a post-cephalic origin for the carapace. The simpler solution is preferred of regarding this structure as discrete paired eyes with a smooth cornea and subjacent crystal cones.The raptorial appendages are post-oral and post-adductor in insertion. They are therefore tentatively identified as the maxillae and maxilliped, but verification of the mandible's position is needed to test this. The postero-ventral battery of “body somites” is reinterpreted as paired protopods of abdominal limbs. A respiratory current is deduced to have entered a branchiostegal chamber ventrally, and left it posterodorsally. It is speculated that the looped linear pattern of intra-cuticular spheres in Paraostenia are photophores. The large eyes with small interommatidial angles were probably used to discern low contrast prey or carrion against a dim background. By analogy with hyperiid amphipods, it is suggested that at least some thylacocephalans were mesopelagic predators. They may have attained neutral buoyancy from their food substrate of shark and coleoids.

Scanning tunneling microscopy (STM) of DNA and RNA

1989 ◽  
Vol 47 ◽  
pp. 34-35
Author(s):  
Patricia G. Arscott ◽  
Gil Lee ◽  
Victor A. Bloomfield ◽  
D. Fennell Evans
Keyword(s):  
Molecular Structures ◽  
Inorganic Materials ◽  
Resolving Power ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Form And Function ◽  
Dna And Rna ◽  
Calf Thymus ◽  
And Function ◽  
The Relationship

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).

Re-examining the form and function of superstition

2011 ◽  
Author(s):  
Scott Fluke ◽  
Russell J. Webster ◽  
Donald A. Saucier
Keyword(s):  
Form And Function ◽  
And Function

A New Form and Function for Personality

2013 ◽  
Author(s):  
Joshua Wilt ◽  
William Revelle
Keyword(s):  
Form And Function ◽  
New Form ◽  
And Function

Ausnahmesegment

2018 ◽  
Vol 48 (191) ◽  
Author(s):  
Barbara Schönig
Keyword(s):  
Welfare State ◽  
Social Housing ◽  
Integrated Approach ◽  
New Paradigm ◽  
Development Models ◽  
Form And Function ◽  
Institutional Organization ◽  
National Welfare ◽  
And Function ◽  
The Welfare State

Going along with the end of the “golden age” of the welfare state, the fordist paradigm of social housing has been considerably transformed. From the 1980s onwards, a new paradigm of social housing has been shaped in Germany in terms of provision, institutional organization and design. This transformation can be interpreted as a result of the interplay between the transformation of national welfare state and housing policies, the implementation of entrepreneurial urban policies and a shift in architectural and urban development models. Using an integrated approach to understand form and function of social housing, the paper characterizes the new paradigm established and nevertheless interprets it within the continuity of the specific German welfare resp. housing regime, the “German social housing market economy”.

Form and Function of the Classical Cadenza

1988 ◽  
Vol 6 (1) ◽  
pp. 27-59 ◽  
Author(s):  
Joseph P. Swain
Keyword(s):  
Form And Function ◽  
And Function
Sign in / Sign up

Export Citation Format

Share Document