The Pelagic Ecosystem of the Bransfield Strait, Antarctica: An Analysis of Microbiological, Planktological and Chemical Characteristics by Multivariate Analyses

1988 ◽  
pp. 160-166
Author(s):  
M. Bölter ◽  
B. von Bodungen ◽  
G. Liebezeit ◽  
M. Meyer
Keyword(s):  
Multivariate Analyses ◽  
Chemical Characteristics ◽  
Pelagic Ecosystem ◽  
Bransfield Strait

scholarly journals A preliminary fish survey of the estuaries on the south-east coast of South Africa, Kei Estuary to Mdumbi: A comparative study

Water SA ◽  
2020 ◽  
Vol 46 (3 July) ◽  
Author(s):  
NC James ◽  
TD Harrison
Keyword(s):  
South Africa ◽  
Significant Relationship ◽  
East Coast ◽  
Multivariate Analyses ◽  
Fish Communities ◽  
Chemical Characteristics ◽  
The South ◽  
Physico Chemical ◽  
Biogeographic Region ◽  
Warm Temperate

A preliminary ichthyofaunal and physico-chemical survey of estuaries on the south-east coast of South Africa from the Kei Estuary to the Mdumbi Estuary was undertaken between October and November 1997. Twenty-seven (27) estuaries were surveyed along this stretch of coastline and these were grouped into three estuary types: small (< 10 ha) predominantly closed estuaries, moderate to large (> 10 ha) predominantly closed estuaries and predominantly open estuaries. Multivariate analyses revealed significant differences between predominantly closed estuaries and predominantly open estuaries in terms of both their physico-chemical characteristics and their fish communities. There was no difference between small and moderate to large predominantly closed estuaries.  A significant relationship was also observed between the physico-chemical characteristics of the estuaries and their fish communities.  The estuaries in the study area fall within the warm-temperate biogeographic region; temperate species dominated the fish communities of all the estuaries. This survey represents one of the few fish surveys undertaken along this little-studied section of the coastline. 

scholarly journals Chemometric Characterization of Synthetic Dye Sorption onto Slovakian River Sediments: A Laboratory Batch Experiment

Separations ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 57
Author(s):  
Anna Koprdová ◽  
Miroslava Bachratá ◽  
Vanda Adamcová ◽  
Martin Valica ◽  
Martin Pipíška ◽  
...  
Keyword(s):  
Multivariate Analyses ◽  
River Sediments ◽  
Principal Component ◽  
Water Hardness ◽  
Exchange Capacity ◽  
Chemical Characteristics ◽  
Physico Chemical ◽  
Dye Sorption ◽  
Conductivity Water ◽  
And Cluster Analysis

The aim of the work was to characterize the sorption of cationic dyes thioflavine T (ThT) and methylene blue (MB) onto selected Slovakian river sediments using chemometric approaches including principal component analysis (PCA) and cluster analysis (CA). Also, the potential of mentioned multivariate analyses for comparison of studied objects (river sediments or river and model waters) as well as in finding relationships between the variables describing the physico-chemical characteristics of studied matrices or waters and sorption/desorption characteristics of matrices for dyes binding under laboratory conditions was evaluated. Parameters describing the physico-chemical characteristics of sediments include: pH, pHzpc, or cation-exchange capacity; and in the case of waters: pH, conductivity, water hardness, content of dissolved solids or presence of organic compounds. From the comparison of dye sorption onto sediments, it was found that sorption of thiazine dye MB was minimally 1.5-times higher than sorption of benzothiazole dye ThT. Sorption capacities Qs reached the maximum values in the case of sediments originated from Dudvah River (MB-Qs = 8.70 ± 0.42 mg g−1; ThT-Qs = 5.03 ± 0.28 mg g−1; ±SD). Obtained results showed that applied methods of multivariate analyses represent a suitable tool for evaluation of sorption/desorption processes of organic xenobiotics binding in sediments.

scholarly journals Habitat characteristics of the rare underground orchid Rhizanthella gardneri

2008 ◽  
Vol 56 (6) ◽  
pp. 501 ◽  
Author(s):  
Jeremy Bougoure ◽  
Mark Brundrett ◽  
Andrew Brown ◽  
Pauline F. Grierson
Keyword(s):  
Soil Chemistry ◽  
Multivariate Analyses ◽  
Mycorrhizal Fungus ◽  
Habitat Characteristics ◽  
Chemical Characteristics ◽  
Viable Option ◽  
Isolated Populations ◽  
Components Analysis ◽  
Vegetation Characteristics ◽  
Tripartite Relationship

Rhizanthella gardneri R.S.Rogers is an entirely subterranean mycoheterotrophic orchid known only from two isolated populations within south-western Western Australia (WA). This rare species appears restricted to habitats dominated by species of the Melaleuca uncinata complex. R. gardneri purportedly forms a tripartite relationship with Melaleuca1, via a connecting mycorrhizal fungus, for the purpose of carbohydrate and nutrient acquisition. Here, we quantify key climate, soil and vegetation characteristics of known R. gardneri habitats to provide baseline data for monitoring of known R. gardneri populations, to better understand how R. gardneri interacts with its habitat and to identify possible new sites for R. gardneri introduction. We found that the habitats of the two known R. gardneri populations show considerable differences in soil chemistry, Melaleuca structure and Melaleuca productivity. Multivariate analyses showed that both multidimensional scaling (MDS) and principal components analysis (PCA) ordinations of soil chemical characteristics were very similar. Individual sites within populations were relatively similar in all attributes measured, whereas overall northern and southern habitats were distinct from each other. These results suggest that R. gardneri can tolerate a range of conditions and may be more widespread than previously thought, given that there are extensive areas of Melaleuca thickets with similar habitat characteristics across south-western WA. Variability within the habitats of known R. gardneri populations suggests translocation of this species into sites with similar vegetation may be a viable option for the survival of this species.

Characterization of defects in tabular silver halide grains

1990 ◽  
Vol 48 (4) ◽  
pp. 1046-1047
Author(s):  
C. Goessens ◽  
D. Schryvers ◽  
J. Van Landuyt ◽  
A. Verbeeck ◽  
R. De Keyzer
Keyword(s):  
Radiation Damage ◽  
Silver Halide ◽  
Chemical Characteristics ◽  
X Ray ◽  
Free Region ◽  
Central Defect ◽  
Crystallographic Defects ◽  
Physical And Chemical ◽  
Two Sides

Silver halide grains (AgX, X=Cl,Br,I) are commonly recognized as important entities in photographic applications. Depending on the preparation specifications one can grow cubic, octahedral, tabular a.o. morphologies, each with its own physical and chemical characteristics. In the present study crystallographic defects introduced by the mixing of 5-20% iodide in a growing AgBr tabular grain are investigated. X-ray diffractometry reveals the existence of a homogeneous Ag(Br1-xIx) region, expected to be formed around the AgBr kernel. In fig. 1 a two-beam BF image, taken at T≈100 K to diminish radiation damage, of a triangular tabular grain is presented, clearly showing defect contrast fringes along four of the six directions; the remaining two sides show similar contrast under relevant diffraction conditions. The width of the central defect free region corresponds with the pure AgBr kernel grown before the mixing with I. The thickness of a given grain lies between 0.15 and 0.3 μm: as indicated in fig. 2 triangular (resp. hexagonal) grains exhibit an uneven (resp. even) number of twin interfaces (i.e., between + and - twin variants) parallel with the (111) surfaces. The thickness of the grains and the existence of the twin variants was confirmed from CTEM images of perpendicular cuts.

Associations Between Informal Caregivers’ Burden and Educational Level

GeroPsych ◽  
2019 ◽  
Vol 32 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Monika Oedekoven ◽  
Katja Amin-Kotb ◽  
Paul Gellert ◽  
Klaus Balke ◽  
Adelheid Kuhlmey ◽  
...  
Keyword(s):  
Support Services ◽  
Educational Level ◽  
Autonomy Support ◽  
Population Survey ◽  
Multivariate Analyses ◽  
Informal Caregivers ◽  
Loss Of Self ◽  
Perceived Burden ◽  
Result Show ◽  
Care Situation

Abstract. We investigated the association between the education of informal caregivers’ (IC) and their physical and mental burden. We hypothesized that better-educated IC would have more resources available to manage the care situation and as a result show lower perceived burden. We conducted a population survey of 6,087 German residents aged 18+ years, 966 of whom reported to be IC. Results show that IC felt more often mentally than physically burdened. In the multivariate analyses, higher-educated IC did not have lower odds of feeling physically burdened than lower-educated IC, though they did have increased odds of feeling mentally burdened. The higher perceived mental burden of higher-educated IC may be related to fear of loss of self-fulfilment and autonomy. Support services should consider the mental burden of higher-educated IC and tailor their interventions accordingly.

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