The Limnology and Fishes of Oligotrophic Glacial Lakes in North America (about 1800 A.D.)

1972 ◽  
Vol 29 (6) ◽  
pp. 617-628 ◽  
Author(s):  
R. A. Ryder
Keyword(s):  
North America ◽  
Adverse Effects ◽  
Species Composition ◽  
Environmental Change ◽  
Growing Season ◽  
Fish Populations ◽  
Chemical Characteristics ◽  
General Description ◽  
Glacial History ◽  
Physical And Chemical

The general limnology and fish composition of 14 North American oligotrophic lakes is described as it likely was about the year 1800, prior to the adverse effects of man-made eutrophication, exploitation, and introductions of exotic species. The general description includes glacial history and geomorphology, climate and growing season, morphometry of the lake basins, physical and chemical characteristics, macroinvertebrates, and zooplankton. Fish populations are described with respect to their zoogeographic origins and the species composition of each lake. The relative degree of environmental change brought about by the activities of man in each lake is summarized.

scholarly journals Spatial Distribution of Zooplankton Diversity across Temporary Pools in a Semiarid Intermittent River

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Thaís X. Melo ◽  
Elvio S. F. Medeiros
Keyword(s):  
Spatial Distribution ◽  
Species Composition ◽  
Spatial Scales ◽  
Temporary Pools ◽  
Chemical Characteristics ◽  
Intermittent Streams ◽  
Variable Environments ◽  
Physical And Chemical ◽  
Total Diversity ◽  
Intermittent River

This study describes the richness and density of zooplankton across temporary pools in an intermittent river of semiarid Brazil and evaluates the partitioning of diversity across different spatial scales during the wet and dry periods. Given the highly patchy nature of these pools it is hypothesized that the diversity is not homogeneously distributed across different spatial scales but concentrated at lower levels. The plankton fauna was composed of 37 species. Of these 28 were Rotifera, 5 were Cladocera, and 4 were Copepoda (nauplii of Copepoda were also recorded). We showed that the zooplankton presents a spatially segregated pattern of species composition across river reaches and that at low spatial scales (among pools or different habitats within pools) the diversity of species is likely to be affected by temporal changes in physical and chemical characteristics. As a consequence of the drying of pool habitats, the spatial heterogeneity within the study river reaches has the potential to increase β diversity during the dry season by creating patchier assemblages. This spatial segregation in community composition and the patterns of partition of the diversity across the spatial scales leads to a higher total diversity in intermittent streams, compared to less variable environments.

Studies of Northern Alberta Lakes and their Fish Populations

1974 ◽  
Vol 31 (5) ◽  
pp. 1007-1020 ◽  
Author(s):  
M. J. Paetz ◽  
K. A. Zelt
Keyword(s):  
Chemical Characteristics ◽  
General Description ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Physical And Chemical Characteristics ◽  
Fish Species Composition ◽  
The Individual ◽  
Cold Lake ◽  
Physical And Chemical ◽  
Northern Alberta

The limnology and fisheries of four Alberta lakes (Cold Lake, Lac La Biche, Lesser Slave Lake, and Wabamun Lake) were described. The general description included glacial history, climate, human development, physical and chemical characteristics, plankton and macroinvertebrates, and fish species composition. Age–length relation for lake whitefish (Coregonus clupeaformis) and ciscoes (C. artedii) from the individual lakes was presented and compared with the limnological condition of the particular lake. The commercial lake whitefish yield of each lake was also compared with the physical and chemical characteristics.

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.

Study of Structural, Physical and Chemical Characteristics of Marshmallow Without Gelatin

Food Industry ◽  
2018 ◽  
Vol 3 (4) ◽  
Author(s):  
Nataliia V. Nepovinnykh ◽  
Yuri A. Kodatsky ◽  
Oksana N. Klyukina ◽  
Nataliia M. Ptichkin ◽  
Samira Yeganehzad
Keyword(s):  
Chemical Characteristics ◽  
Physical And Chemical Characteristics ◽  
Physical And Chemical

Effects of Chlormequat-Uniconazole 30% Micro-Emulsion on Stem Physical and Chemical Characteristics of Rice

2013 ◽  
Vol 39 (6) ◽  
pp. 1089
Author(s):  
Qian ZHANG ◽  
Ming-Cai ZHANG ◽  
Hai-Yan ZHANG ◽  
Wei-Ming TAN ◽  
Zhao-Hu LI ◽  
...  
Keyword(s):  
Chemical Characteristics ◽  
Physical And Chemical Characteristics ◽  
Micro Emulsion ◽  
Physical And Chemical

Physical and Chemical Characteristics of Meats of the Indonesian Indigenous Crossbred Chickens Fed Fermented Mixture of Papaya (Carica papaya L.) Leaf and Seed Meal

2020 ◽  
Keyword(s):  
Crude Protein ◽  
Control Diet ◽  
Dietary Treatment ◽  
Seed Meal ◽  
Chemical Characteristics ◽  
Breast Meat ◽  
Ph Values ◽  
Physical And Chemical Characteristics ◽  
Dietary Treatments ◽  
Physical And Chemical

The objective of this present study was to investigate the effect of feeding fermented mixture of papaya leaf and seed meal (FERM) on the physical and chemical characteristics of meats of the Indonesian indigenous crossbred chicken (IICC). The study was carried out with 300 day-old IICC. The chicks were randomly distributed to five treatment groups, i.e., CONT (control diet based on corn-soybean- diet), FERMA (diet containing 1% FERM), FERMB (2.5% FERM), FERMC (5% FERM) and FERMD (7.5% FERM). Each treatment group consisted of 6 replicates with 10 IICC in each. At week 8, one chick from each replicate was randomly taken and slaughtered. After being de-feathered and eviscerated, samples from breast and thigh meats were obtained. Results showed that the increased levels of FERM was followed by the increased (P<0.05) pH values, moisture and crude protein content of breast meats of the IICC. Dietary incorporation of FERM especially at the level of 2.5% increased (P<0.05) the content of fat in the breast meat of IICC, while further increased levels of FERM did not alter (P>0.05) the fat content of the IICC breast meat. Dietary treatment did not have any effect (P>0.05) on the lightness (L*) values of breast meat of the IICC. The redness (a*) values were higher (P<0.05) in FERMD breast meat than other. FERM diet resulted in lower (P<0.05) yellowness (b*) values in the IICC breast meat. The pH values and moisture content of thigh meat increased (P<0.05) with the increased level of FERM. The WHC decreased (P<0.05) with the elevated levels of FERM in the diets. There was an increase (P<0.05) in crude protein concentration in FERMA as compared to the other meats. Crude fat and ash concentrations in thigh meat were affected (P<0.05) by the treatments. Dietary treatments had no impact (P>0.05) on L* values of thigh meats. Feeding FERM at 7.5% from diets increased (P<0.05) and decreased (P<0.05) the redness and yellowness of meats. In conclusion, dietary inclusion of FERM especially at the level of 7.5% from diets improved the physical and chemical characteristics of the IICC meats.

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