Development of mantle organs, feeding, and locomotion in postlarval Macoma balthica (L.) (Lamellibranchiata)

1969 ◽  
Vol 47 (4) ◽  
pp. 609-617 ◽  
Author(s):  
J. F. Caddy
Keyword(s):  
Shell Length ◽  
Macoma Balthica ◽  
Adult Form ◽  
Form And Function ◽  
Mantle Edge ◽  
Inhalant Siphon ◽  
And Function ◽  
Development Proceeds

Postlarval M. balthica is well adapted for interstitial life in a particulate sediments, although metamorphosis to the adult form and function is not complete until a shell length of 2 mm is reached.Spatfall at 300–310 μ shell length is followed by a plantigrade stage in which the ciliated plantiform foot is used as an organ of feeding, locomotion, and rejection of pseudofaeces. The inhalant current is produced by the ciliation of the foot and inner demibranch, and enters through the pedal gape. This is already separated from the lumen of the inhalant siphon by the cruciform apparatus. Food sorting in the early postlarvae is exclusively by the palps, which are well developed in the midline to overhang the mouth, and already have simple sorting ridges on their inner surfaces.Siphon development proceeds by infolding of the fusions of the mantle edge around the siphonal apertures. In early postlarvae the pseudofaeces are transported to the pedal gape by the mantle ciliary tract, and swept from the mantle edge by the foot. At approximately 1 mm shell length, rejection of pseudofaeces occurs via the inhalant siphon, which only gradually takes over its adult function as exclusive route of the inhalant current at between 1 and 2 mm.

The Development of Form and Function in Fishes and the Question of Larval Adaptation

2004 ◽  
Keyword(s):  
Gas Exchange ◽  
Ion Exchange ◽  
Larval Period ◽  
Primary Site ◽  
Form And Function ◽  
Large Numbers ◽  
Ecological Implications ◽  
Gill Lamellae ◽  
And Function ◽  
Development Proceeds

<em>Abstract.</em>—This review examines the transition from cutaneous to branchial respiration and ionoregulation in teleost larvae. Before gills develop, the skin is the only significant site of gas and ion exchange. The primary site of these two processes shifts from the skin to the gill as development proceeds. When the transition begins and the speed at which it occurs, both vary considerably depending on species. In general, ionoregulatory activity begins to shift to the gill before gas exchange. The transition to branchial ionoregulation also tends to proceed more rapidly than the transition to branchial respiration. The key morphological indicator of the shift in ionoregulatory activity to the gill is the appearance of large numbers of mitochondria-rich cells on gill arches. The corresponding indicator for gas exchange is the appearance of gill lamellae. For both activities, the transition occurs gradually, and even at the end of the larval period, the skin still plays an important role in both processes. This is particularly true for gas exchange. The ecological implications of the transitions and what they may mean in terms of gill evolution are discussed.

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
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