Two General Metapopulation Models and the Core-Satellite Species Hypothesis

1993 ◽  
Vol 142 (1) ◽  
pp. 17-41 ◽  
Author(s):  
Ilkka Hanski ◽  
Mats Gyllenberg
Keyword(s):  
The Core ◽  
Metapopulation Models ◽  
Satellite Species

ANALYSIS OF THE DISTRIBUTION OF EPIPHYTIC LICHENS ON QUERCUS PUBESCENS ALONG AN ALTITUDINAL GRADIENT IN A MEDITERRANEAN AREA (TUSCANY, CENTRAL ITALY)

1997 ◽  
Vol 45 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Stefano Loppi ◽  
Stergios Arg. Pirintsos ◽  
Vincenzo De Dominicis
Keyword(s):  
Altitudinal Gradient ◽  
Central Italy ◽  
Mediterranean Area ◽  
Multivariate Techniques ◽  
Epiphytic Lichens ◽  
Climatic Parameters ◽  
Quercus Pubescens ◽  
Epiphytic Lichen ◽  
The Core ◽  
Satellite Species

The distribution of epiphytic lichens on Quercus pubescens in Tuscany, central Italy, was studied by means of multivariate techniques along an altitudinal gradient from 0 to 900 m. Great differences in community structure were found and the altitude of 500 m was identified as an ecotone. Epiphytic lichen vegetation on trees below the ecotone varied significantly in relation to bark pH. Climatic parameters (temperature and rainfall) were probably related to altitude. Dust was probably responsible for the rise in bark pH. The distribution of lichen species in the sampling belts fitted the core-satellite hypothesis. The use of core and satellite species as biomonitors of air pollution and bioindicators of environmental conditions is discussed.

scholarly journals Community Assembly and Co-occurrence Patterns Underlying the Core and Satellite Bacterial Sub-communities in the Tibetan Lakes

2021 ◽  
Vol 12 ◽  
Author(s):  
Qi Yan ◽  
Jianming Deng ◽  
Feng Wang ◽  
Yongqin Liu ◽  
Keshao Liu
Keyword(s):  
Community Assembly ◽  
454 Sequencing ◽  
Species Traits ◽  
Rrna Gene ◽  
Natural Environments ◽  
Ecological Processes ◽  
The Core ◽  
Core Species ◽  
Occurrence Patterns ◽  
Satellite Species

Microbial communities normally comprise a few core species and large numbers of satellite species. These two sub-communities have different ecological and functional roles in natural environments, but knowledge on the assembly processes and co-occurrence patterns of the core and satellite species in Tibetan lakes is still sparse. Here, we investigated the ecological processes and co-occurrence relationships of the core and satellite bacterial sub-communities in the Tibetan lakes via 454 sequencing of 16S rRNA gene. Our studies indicated that the core and satellite bacterial sub-communities have similar dominant phyla (Proteobacteria, Bacteroidetes, and Actinobacteria). But the core sub-communities were less diverse and exhibited a stronger distance-decay relationship than the satellite sub-communities. In addition, topological properties of nodes in the network demonstrated that the core sub-communities had more complex and stable co-occurrence associations and were primarily driven by stochastic processes (58.19%). By contrast, the satellite sub-communities were mainly governed by deterministic processes (62.17%). Overall, this study demonstrated the differences in the core and satellite sub-community assembly and network stability, suggesting the importance of considering species traits to understand the biogeographic distribution of bacterial communities in high-altitude lakes.

Intestinal helminths of lesser scaup ducks: patterns of association

1986 ◽  
Vol 64 (1) ◽  
pp. 132-141 ◽  
Author(s):  
Albert O. Bush ◽  
John C. Holmes
Keyword(s):  
Differential Susceptibility ◽  
The Other ◽  
Intestinal Helminths ◽  
Gammarus Lacustris ◽  
The Core ◽  
Core Species ◽  
Lesser Scaup ◽  
Associated Species ◽  
Satellite Species ◽  
Basic Similarity

The helminth communities of the small intestines of 45 lesser scaup ducks sampled from 13 lakes in Alberta, Canada, were examined for patterns of association among species. A core of eight frequent, numerous, and positively associated species provided a basic similarity across all host individuals. Six of these core species are specialists in lesser scaup, and the other two are generalists in waterfowl. A group of eight moderately frequent and numerous species, which were positively associated with the core species but not with each other, also contributed to this similarity; these secondary species included two specialists in scaup and three generalists in waterfowl. The 36 remaining "satellite species" appeared to be distributed randomly among birds. Variations among communities in individual birds were due largely to (i) differences in the numbers of two suites of helminth species, one using Hyalella azteca and the other Gammarus lacustris as intermediate host; (ii) differences in the numbers of the Hyalella suite, and in the presence or absence of some secondary or satellite species, associated with the lake from which the duck was taken; and (iii) differences in the total numbers of helminths per duck, which may be associated with differential susceptibility of individual ducks.

Sampling error can cause false rejection of the core-satellite species hypothesis

Oecologia ◽  
2001 ◽  
Vol 126 (3) ◽  
pp. 360-362 ◽  
Author(s):  
Vojtech Novotny ◽  
Pavel Drozd
Keyword(s):  
Sampling Error ◽  
The Core ◽  
Satellite Species ◽  
False Rejection

Common and rare trout parasites in a small landscape system

Parasitology ◽  
1993 ◽  
Vol 106 (1) ◽  
pp. 101-105 ◽  
Author(s):  
R. Hartvigsen ◽  
O. Halvorsen
Keyword(s):  
Salmo Salar ◽  
Carrying Capacity ◽  
Salmo Trutta ◽  
Rescue Effect ◽  
The Core ◽  
Core Species ◽  
Landscape System ◽  
Colonization Ability ◽  
Effect Hypothesis ◽  
Satellite Species

SUMMARYBrown trout (Salmo trutta) from four lakes within an area of approximately 40 km2 were found to harbour nine helminth species. Crepidostomum metoecus could be classified as core species, while Crepidostomum farionis had an intermediate position. All the others could be classified as satellite species. Salmon (Salmo salar) fingerlings were grown to smolts in an earthpond over the summer. The fingerlings became infected with Crepidostomum spp. which may indicate a superior colonization ability in the core species. The results support the ‘rescue effect hypothesis’ rather than the ‘carrying capacity hypothesis’.

What face familiarity feelings say about the lateralization of specific entities within the core system

2019 ◽  
Vol 42 ◽  
Author(s):  
Guido Gainotti
Keyword(s):  
Temporal Lobe ◽  
Memory System ◽  
Core System ◽  
The Core ◽  
Memory Traces ◽  
Specific Memory ◽  
Target Article ◽  
Temporal Structures ◽  
The Right

Abstract The target article carefully describes the memory system, centered on the temporal lobe that builds specific memory traces. It does not, however, mention the laterality effects that exist within this system. This commentary briefly surveys evidence showing that clear asymmetries exist within the temporal lobe structures subserving the core system and that the right temporal structures mainly underpin face familiarity feelings.

A scanning electron microscopic study on dissolving process of cholesterol gallstones by chenodeoxycholic acid (CDCA)

1978 ◽  
Vol 36 (2) ◽  
pp. 522-523
Author(s):  
T. Kanetaka ◽  
M. Cho ◽  
S. Kawamura ◽  
T. Sado ◽  
K. Hara
Keyword(s):  
Electron Microscope ◽  
Chenodeoxycholic Acid ◽  
Outer Surface ◽  
Electron Microscopic ◽  
Cholesterol Gallstones ◽  
The Core ◽  
Scanning Electron Microscopic Study ◽  
Scanning Electron Microscopic ◽  
Acceleration Voltage ◽  
Scanning Electron

The authors have investigated the dissolution process of human cholesterol gallstones using a scanning electron microscope(SEM). This study was carried out by comparing control gallstones incubated in beagle bile with gallstones obtained from patients who were treated with chenodeoxycholic acid(CDCA).The cholesterol gallstones for this study were obtained from 14 patients. Three control patients were treated without CDCA and eleven patients were treated with CDCA 300-600 mg/day for periods ranging from four to twenty five months. It was confirmed through chemical analysis that these gallstones contained more than 80% cholesterol in both the outer surface and the core.The specimen were obtained from the outer surface and the core of the gallstones. Each specimen was attached to alminum sheet and coated with carbon to 100Å thickness. The SEM observation was made by Hitachi S-550 with 20 kV acceleration voltage and with 60-20, 000X magnification.

The Structure and Development of Microbodies in the Fat Body and other Tissues of an Insect (Calpodes Ethlius)

1970 ◽  
Vol 28 ◽  
pp. 148-149
Author(s):  
M. Locke ◽  
J. T. McMahon
Keyword(s):  
Electron Microscopy ◽  
Liquid Crystals ◽  
Fat Body ◽  
Competitive Inhibitor ◽  
Dense Core ◽  
Urate Oxidase ◽  
Blood Proteins ◽  
Free Base ◽  
The Core ◽  
The Matrix

The fat body of insects has always been compared functionally to the liver of vertebrates. Both synthesize and store glycogen and lipid and are concerned with the formation of blood proteins. The comparison becomes even more apt with the discovery of microbodies and the localization of urate oxidase and catalase in insect fat body.The microbodies are oval to spherical bodies about 1μ across with a depression and dense core on one side. The core is made of coiled tubules together with dense material close to the depressed membrane. The tubules may appear loose or densely packed but always intertwined like liquid crystals, never straight as in solid crystals (Fig. 1). When fat body is reacted with diaminobenzidine free base and H2O2 at pH 9.0 to determine the distribution of catalase, electron microscopy shows the enzyme in the matrix of the microbodies (Fig. 2). The reaction is abolished by 3-amino-1, 2, 4-triazole, a competitive inhibitor of catalase. The fat body is the only tissue which consistantly reacts positively for urate oxidase. The reaction product is sharply localized in granules of about the same size and distribution as the microbodies. The reaction is inhibited by 2, 6, 8-trichloropurine, a competitive inhibitor of urate oxidase.

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