scholarly journals Multivariate statistical assessment and spatial distribution of groundwater contamination in Neke and its environs, South-Eastern Nigeria

2019 ◽  
Vol 14 (8) ◽  
pp. 62-80 ◽  
Author(s):  
Solomon Obialo Onwuka ◽  
Chimankpam Kenneth Ezugwu
Keyword(s):  
Spatial Distribution ◽  
Groundwater Contamination ◽  
Multivariate Statistical ◽  
Statistical Assessment ◽  
South Eastern

Spatial distribution of Antarctic shrimps (Crustacea: Decapoda) by underwater photography

1991 ◽  
Vol 3 (4) ◽  
pp. 363-369 ◽  
Author(s):  
Julian Gutt ◽  
M. Gorny ◽  
W. Arntz
Keyword(s):  
Spatial Distribution ◽  
Continental Shelf ◽  
Weddell Sea ◽  
Small Scale ◽  
Frequency Distributions ◽  
South Eastern ◽  
Direct Observations ◽  
Underwater Photography ◽  
Dispersion Patterns ◽  
Eastern Weddell Sea

Three species of shrimps (Notocrangon antarcticus, Chorismus antarcticus, Nematocarcinus lanceopes) were investigated in the south-eastern Weddell Sea using of underwater photography. Maximum densities of c. 100 specimens per 100 m2 were found for N. antarcticus on the continental shelf (200–600 m) and for N. lanceopes on the slope (800–1200 m). Small-scale dispersion patterns and size-frequency distributions were analyzed within dense concentrations. These direct observations indicate that the behaviour of the three species is adapted to different habitats with Chorismus distribution correlated with that of sponges and Notocrangon with base sediment.

Spatial distribution of some microbial trophic groups in a plug-flow-type anaerobic bioreactor treating swine manure

2010 ◽  
Vol 61 (5) ◽  
pp. 1147-1155 ◽  
Author(s):  
Guylaine Talbot ◽  
Caroline S. Roy ◽  
Edward Topp ◽  
Martin L. Kalmokoff ◽  
Stephen P. J. Brooks ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Plug Flow ◽  
Swine Manure ◽  
Trophic Groups ◽  
Phylogenetic Groups ◽  
Multivariate Statistical ◽  
Anaerobic Bioreactor ◽  
Methanogenic Activity ◽  
Flow Type ◽  
Sequential Digestion

Anaerobic digestion of swine manure is carried out by a consortium of microbial species, including volatile fatty acid (VFA) producers, VFA-degraders and methanogens. The distribution of five phylogenetic groups within a plug-flow-type anaerobic bioreactor consisting of eight serially-connected tanks was examined through the sequential digestion of swine manure. Quantification was carried out using reverse transcription real-time PCR (RT-Q-PCR) assays targeting the 16S rRNA of Clostridium (cluster XIVa), Peptostreptococcus, Syntrophomonas, Methanosaeta, and Methanosarcina spp. The VFA producers Peptostreptococcus spp. and Clostridium spp. were found predominantly in compartments where hydrolysis/acidogenesis took place. The spatial distribution of the aceticlastic methanogens, Methanosaeta and Methanosarcina, within the bioreactor was not correlated with methanogenic activity. In contrast the VFA-degrading genus Syntrophomonas spp. was more abundant in compartments with elevated methanogenic activity. Multivariate statistical analyses of the RT-Q-PCR data have provided new insights into our understanding of how the various trophic groups were distributed within this bioreactor system. While the distribution of clostridia, peptostreptococci and Syntrophomonas corresponded to their known metabolic functions, aceticlastic methanogens were not apparently linked to the methanogenesis stage occurring in latter compartments, suggesting that hydrogenotrophic methanogens were the primary methane generators in this bioreactor. However, aceticlastic methanogens could be involved in compartments related to the hydrolysis/acidogenesis stage.

Spatial Distribution of Pink Wax Scale, Ceroplastes Rubens Maskell (Hemiptera: Coccidae), on Umbrella Trees in South-Eastern Queensland: the Pattern of Outbreaks

1996 ◽  
Vol 44 (6) ◽  
pp. 599 ◽  
Author(s):  
AD Loch ◽  
MP Zalucki
Keyword(s):  
Biological Control ◽  
Spatial Distribution ◽  
Spatial Pattern ◽  
Patchy Distribution ◽  
Death Rates ◽  
Limited Movement ◽  
South Eastern ◽  
Environmental Suitability ◽  
First Instar ◽  
Dispersal Success

The spatial pattern of outbreaks of pink wax scale, Ceroplastes rubens Maskell, within and among umbrella trees, Schefflera actinophylla (Endl.), in southeastern Queensland was investigated. Pink wax scale was common on S. actinophylla, with approximately 84% of trees positive for scale and 14% of bees recording outbreak densities exceeding 0.4 adults per leaflet. Highly aggregated distributions of C. rubens occur within and among umbrella trees. Clumped distributions within trees appear to result from variable birth and death rates and limited movement of first instar crawlers. The patchy distribution of pink wax scale among trees is probably a consequence of variation in dispersal success of scale, host and environmental suitability for establishment and rates of biological control. Pink wax scale was more prevalent on trees in roadside positions and in exposed situations, indicating that such trees are more suitable and/or susceptible to scale colonisation.

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