Dynamics of Regional Distribution: The Core and Satellite Species Hypothesis

Oikos ◽  
1982 ◽  
Vol 38 (2) ◽  
pp. 210 ◽  
Author(s):  
Ilkka Hanski
Keyword(s):  
Regional Distribution ◽  
The Core ◽  
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.

scholarly journals Evolution of Regional Changes in Apparent Diffusion Coefficient during Focal Ischemia of Rat Brain: The Relationship of Quantitative Diffusion NMR Imaging to Reduction in Cerebral Blood Flow and Metabolic Disturbances

1995 ◽  
Vol 15 (6) ◽  
pp. 1002-1011 ◽  
Author(s):  
Mathias Hoehn-Berlage ◽  
David G. Norris ◽  
Kanehisa Kohno ◽  
Günter Mies ◽  
Dieter Leibfritz ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Apparent Diffusion Coefficient ◽  
Regional Distribution ◽  
Atp Depletion ◽  
Nmr Imaging ◽  
Metabolic Disturbances ◽  
Adc Value ◽  
The Core ◽  
Apparent Diffusion ◽  
Tissue Acidosis

Middle cerebral artery occlusion was performed in rats while the animals were inside the nuclear magnetic resonance (NMR) tomograph. Successful occlusion was confirmed by the collapse of amplitude on an electrocorticogram. The ultrafast NMR imaging technique UFLARE was used to measure the apparent diffusion coefficient (ADC) immediately after the induction of cerebral ischemia. ADC values of normal cortex and caudate-putamen were 726 ± 22 × 10−6 mm2/s and 659 ± 17 × 10−6 mm2/s, respectively. Within minutes of occlusion, a large territory with reduced ADC became visible in the ipsilateral hemisphere. Over the 2 h observation period, this area grew continuously. Quantitative analysis of the ADC reduction in this region showed a gradual ADC decrease from the periphery to the core, the lowest ADC value amounting to about 60% of control. Two hours after the onset of occlusion, the regional distribution of ATP and tissue pH were determined with bioluminescence and fluorescence techniques, respectively. There was a depletion of ATP in the core of the ischemic territory (32 ± 20% of the hemisphere) and an area of tissue acidosis (57 ± 19% of the hemisphere) spreading beyond that of ATP depletion. Regional CBF (rCBF) was measured autoradiographically with the iodo[14C]antipyrine method. CBF gradually decreased from the periphery to the ischemic core, where it declined to values as low as 5 ml 100 g−1 min−1. When reductions in CBF and in ADC were matched to the corresponding areas of energy breakdown and of tissue acidosis, the region of energy depletion corresponded to a threshold in rCBF of 18 ± 14 ml 100 g−1 min−1 and to an ADC reduction to 77 ± 3% of control. Tissue acidosis corresponded to a flow value below 31 ± 11 ml 100 g−1 min−1 and to an ADC value below 90 ± 4% of control. Thus, the quantification of ADC in the ischemic territory allows the distinction between a core region with total breakdown of energy metabolism and a corona with normal energy balance but severe tissue acidosis.

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

Micas of the muscovite–lepidolite series from Karibib pegmatites, Namibia

2007 ◽  
Vol 71 (1) ◽  
pp. 41-62 ◽  
Author(s):  
E. Roda ◽  
P. Keller ◽  
A. Pesquera ◽  
F. Fontan
Keyword(s):  
Chemical Composition ◽  
General Trend ◽  
Regional Distribution ◽  
Rare Element ◽  
Core Zone ◽  
The Core ◽  
Dome Structure ◽  
Compositional Variations ◽  
High Level ◽  
Internal Evolution

AbstractMicas of the muscovite–lepidolite series are main constituents of the evolved pegmatites from the Okatjimukuju-Kaliombo portion of the Karibib belt, Namibia. The compositional variations shown by the micas from the intermediate zones are mainly controlled by the Li3Al-1□-2 and SiLi2Al-2□-1 substitution schemes, whereas for the micas from the core margins and the replacement bodies, only the first of these two exchange vectors seems to operate. The chemical composition of the micas not only depends on the degree of pegmatite evolution, but also on the position in the internal zonation of the pegmatite. Micas from the core margins and the replacement units are generally richer in F, Li, Rb, Cs and Zn than those from the intermediate zones. In general, the contents of these elements increase with decreasing K/Rb ratio. However, some data departing from this general trend are also observed, which could be related to subsolidus processes. Some pegmatite bodies show a complete internal evolution, developed from the margins to the core zone, which is reflected in the chemical composition of the micas. The regional distribution of pegmatites does not define a zonation, because an overlapping of pegmatites with different degrees of evolution occurs. This could be due to the high level of evolution attained by most of the rare-element pegmatites, and to their topography with respect to a dome structure of the basement.

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

scholarly journals Spatial Analysis of the COVID-19 Pandemic in Hungary

REGION ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 147-165
Author(s):  
Annamaria Uzzoli ◽  
Sándor Zsolt Kovács ◽  
Attila Fábián ◽  
Balázs Páger ◽  
Tamás Szabó
Keyword(s):  
Regional Distribution ◽  
Spatial Dynamics ◽  
Spatial Relation ◽  
Third Wave ◽  
The Novel ◽  
Epidemic Spreading ◽  
Community Based ◽  
The Core ◽  
Novel Coronavirus ◽  
Geographical Dimension

This paper examines the spatial dynamics and regional distribution of the novel coronavirus epidemic in Hungary in an effort to obtain a deeper understanding of the connection between space and health. The paper also presents comprehensive epidemiologic data on the spatiotemporal spread of the COVID-19 pandemic in terms of the epidemic waves. Following a comparison of the growth rates of infection numbers, the current study explores the geographical dimension of the three pandemic waves. The partial transformation of spatial characteristics during the three epidemic waves is among the most important results found. While geographical hotspots influenced the first wave, newly confirmed coronavirus cases in the second and third waves were due to community-based epidemic spreading. Furthermore, the western-eastern spatial relation and the core-periphery model also affected the regional distribution of new cases and deaths in the initial two waves. However, a new spatial pattern - realised by the northern-southern spatial orientation - appeared during the third wave. The outputs of this paper offer feasible suggestions for evidence-based policymaking in pandemic prevention, mitigation, and preparedness.

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.

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