The Importance of Size-Dependent Processes in the Ecology of Deposit-Feeding Benthos

1989 ◽  
pp. 171-200 ◽  
Author(s):  
Thomas L. Forbes
Keyword(s):  
Size Dependent ◽  
Deposit Feeding ◽  
Dependent Processes

Grain size and transport biases in an Ediacaran detrital zircon record

2021 ◽  
Vol 91 (9) ◽  
pp. 913-928
Author(s):  
Marjorie D. Cantine ◽  
Jacob B. Setera ◽  
Jill A. Vantongeren ◽  
Chiza Mwinde ◽  
Kristin D. Bergmann
Keyword(s):  
Grain Size ◽  
Detrital Zircon ◽  
Size Variation ◽  
Heavy Mineral ◽  
Death Valley ◽  
Size Dependent ◽  
Sedimentary System ◽  
The Relationship ◽  
Dependent Processes

ABSTRACT Detrital-zircon records of provenance are used to reconstruct paleogeography, sediment sources, and tectonic configuration. Recognition of biases in detrital-zircon records that result from grain-size-dependent processes adds new complexity and caution to the interpretation of these records. We begin by investigating possible size-dependent biases that may affect interpretation of detrital-zircon provenance records in an idealized sedimentary system. Our modeling results show that settling and selective entrainment can differentially affect detrital-zircon spectra if an initial size variation between source zircon populations exists. We then consider a case study: a detrital-zircon record from Ediacaran to Terreneuvian strata of Death Valley, USA, with a focus on the Rainstorm Member of the Johnnie Formation. The detrital-zircon record of the Rainstorm Member shows that despite its unusual, heavy-mineral-rich character, the provenance of the unit is like other units in the succession. Size and density measurements of the grains of the deposit suggest that its enriched heavy-mineral suite is best explained through concentration by selective entrainment and winnowing. The relationship between detrital-zircon grain size and age for samples from the Johnnie Formation are consistent with grain-size influence on the interpretation of provenance, especially for large Grenville-age (1.0–1.2 Ga) zircons. Grain size can exert significant bias on a provenance interpretation and must be accounted for in provenance studies.

Size‐Dependent Processes Underlying Regularities in Ecosystem Structure

1987 ◽  
Vol 57 (3) ◽  
pp. 233-250 ◽  
Author(s):  
L. M. Dickie ◽  
S. R. Kerr ◽  
P. R. Boudreau
Keyword(s):  
Ecosystem Structure ◽  
Size Dependent ◽  
Dependent Processes

Structure and Transformation of Fish Production Systems

1977 ◽  
Vol 34 (10) ◽  
pp. 1989-1994 ◽  
Author(s):  
S. R. Kerr
Keyword(s):  
Community Ecology ◽  
Key Words ◽  
Production Systems ◽  
Commercial Fisheries ◽  
Fish Production ◽  
Lake Productivity ◽  
Control Variables ◽  
Size Dependent ◽  
Dependent Processes ◽  
Pelagic Fisheries

A tentative synthesis is provided of some considerations that emerged from the PERCIS proceedings. The percid composition of commercial fisheries tends to be relatively conservative except where abrupt community transformations, characterizable as fold catastrophes, mark the effects of critical conjunctions of fishing intensity and lake productivity acting jointly as control variables. These behaviors of fish production systems are consistent in general with current observations and theory based upon size-dependent processes in marine pelagic fisheries. Key words: theory, percidae, community ecology, fishing intensity, production systems

Size-dependent competitive ability in a deposit-feeding amphipod, Monoporeia affinis

Oikos ◽  
2002 ◽  
Vol 97 (1) ◽  
pp. 31-44 ◽  
Author(s):  
Albashir A. Aljetlawi ◽  
Kjell Leonardsson
Keyword(s):  
Competitive Ability ◽  
Size Dependent ◽  
Deposit Feeding

Production and STEM examination of controlled-size silver clusters

1983 ◽  
Vol 41 ◽  
pp. 338-339
Author(s):  
M. A. Listvan ◽  
R. P. Andres
Keyword(s):  
Cluster Size ◽  
Metal Clusters ◽  
Experimental Parameter ◽  
Carbon Films ◽  
Metal Species ◽  
Silver Clusters ◽  
Free Jet ◽  
Size Dependent ◽  
Cluster Properties ◽  
Controllable Size

Knowledge of the function and structure of small metal clusters is one goal of research in catalysis. One important experimental parameter is cluster size. Ideally, one would like to produce metal clusters of regulated size in order to characterize size-dependent cluster properties.A source has been developed which is capable of producing microscopic metal clusters of controllable size (in the range 5-500 atoms) This source, the Multiple Expansion Cluster Source, with a Free Jet Deceleration Filter (MECS/FJDF) operates as follows. The bulk metal is heated in an oven to give controlled concentrations of monomer and dimer which were expanded sonically. These metal species were quenched and condensed in He and filtered to produce areosol particles of a controlled size as verified by mass spectrometer measurements. The clusters were caught on pre-mounted, clean carbon films. The grids were then transferred in air for microscopic examination. MECS/FJDF was used to produce two different sizes of silver clusters for this study: nominally Ag6 and Ag50.

Transfer Technique for Electron Microscopy of Membrance Filter Samples

1974 ◽  
Vol 32 ◽  
pp. 554-555
Author(s):  
Lawrence W. Ortiz ◽  
Bonnie L. Isom
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Pore Size ◽  
Membrane Filters ◽  
Size Dependent

A procedure is described for the quantitative transfer of fibers and particulates collected on membrane filters to electron microscope (EM) grids. Various Millipore MF filters (Millipore AA, HA, GS, and VM; 0.8, 0.45, 0.22 and 0.05 μm mean pore size) have been used with success. Observed particle losses have not been size dependent and have not exceeded 10%. With fibers (glass or asbestos) as the collected media this observed loss is approximately 3%.

Spindle scaling mechanisms

2020 ◽  
Vol 64 (2) ◽  
pp. 383-396
Author(s):  
Lara K. Krüger ◽  
Phong T. Tran
Keyword(s):  
Cell Size ◽  
Spindle Assembly ◽  
Dependent Manner ◽  
Post Translational Modification ◽  
Size Dependent ◽  
A Cell ◽  
Chromosome Separation ◽  
Spindle Elongation ◽  
Protein Gradients ◽  
Spindle Structure

Abstract The mitotic spindle robustly scales with cell size in a plethora of different organisms. During development and throughout evolution, the spindle adjusts to cell size in metazoans and yeast in order to ensure faithful chromosome separation. Spindle adjustment to cell size occurs by the scaling of spindle length, spindle shape and the velocity of spindle assembly and elongation. Different mechanisms, depending on spindle structure and organism, account for these scaling relationships. The limited availability of critical spindle components, protein gradients, sequestration of spindle components, or post-translational modification and differential expression levels have been implicated in the regulation of spindle length and the spindle assembly/elongation velocity in a cell size-dependent manner. In this review, we will discuss the phenomenon and mechanisms of spindle length, spindle shape and spindle elongation velocity scaling with cell size.

Sign in / Sign up

Export Citation Format

Share Document