scholarly journals Phosphatase activity and nitrogen fixation reflect species differences, not nutrient trading or nutrient balance, across tropical rainforest trees

2018 ◽  
Vol 21 (10) ◽  
pp. 1486-1495 ◽  
Author(s):  
Sarah A. Batterman ◽  
Jefferson S. Hall ◽  
Benjamin L. Turner ◽  
Lars O. Hedin ◽  
J. Kimiko LaHaela Walter ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Phosphatase Activity ◽  
Tropical Rainforest ◽  
Species Differences ◽  
Nutrient Balance ◽  
Nutrient Trading

Effects of desiccation and rehydration on nitrogen fixation by epiphylls in a tropical rainforest

1980 ◽  
Vol 6 (2) ◽  
pp. 109-113 ◽  
Author(s):  
Barbara L. Bentley ◽  
Edward J. Carpenter
Keyword(s):  
Nitrogen Fixation ◽  
Tropical Rainforest

Effects of tropical rainforest roads on small mammals: inhibition of crossing movements

2001 ◽  
Vol 28 (4) ◽  
pp. 351 ◽  
Author(s):  
Miriam Goosem
Keyword(s):  
Breeding Season ◽  
Small Mammals ◽  
Tropical Rainforest ◽  
Species Differences ◽  
Vegetative Cover ◽  
The Road ◽  
Barrier Effects ◽  
Linear Barrier ◽  
North Eastern ◽  
Wide Road

Along a narrow, unsealed road through rainforest in north-eastern Queensland, movements of small mammals were examined to determine whether the road would inhibit road crossings, thereby causing linear barrier effects. Crossings of a 12- or 20-m-wide road clearing by Melomys cervinipes were severely inhibited, crossing inhibition of Rattus sp. was less severe, while crossings by Uromys caudimaculatus were unaffected. This differential effect was attributed to species differences in size, mobility and behaviour. Baiting on only one side of the road increased crossing rates for all species. During the breeding season, crossings of 20-m clearings by Rattus sp. were almost completely inhibited and were significantly fewer than crossings of 12-m clearings. Clearing width had little effect on crossing rate outside the breeding season. Seasonal dispersal of juvenile and breeding animals appeared to explain this discrepancy in clearing-width effects. Rattus sp. were significantly less likely to cross a road where there was no vegetative cover at the entrance to a road culvert than where there was cover at both culvert entrances. Linear barrier effects for small mammals may be mitigated by narrower road-clearing widths, by replanting of grassy road verges resulting in increased cover at culvert entrances and canopy closure above the road, and by providing more faunal underpasses.

GRAIN LEGUMES IN PEARL MILLET SYSTEMS IN NORTHERN NAMIBIA: AN ASSESSMENT OF POTENTIAL NITROGEN CONTRIBUTIONS

2003 ◽  
Vol 39 (4) ◽  
pp. 349-362 ◽  
Author(s):  
J. F. McDONAGH ◽  
A. E. M. HILLYER
Keyword(s):  
Nitrogen Fixation ◽  
Soil Fertility ◽  
Pearl Millet ◽  
Pennisetum Glaucum ◽  
Nutrient Balance ◽  
Grain Legumes ◽  
Residue Management ◽  
Grain Legume ◽  
Management Options ◽  
Nitrogen Inputs

A nutrient-balance model was used to investigate the nitrogen contributions of cowpea (Vigna unguiculata) to pearl millet (Pennisetum glaucum) intercropping systems in semi-arid northern Namibia. Data on nitrogen fixation, production, crop nitrogen off-take and competition effects came from two seasons of fieldwork. Supplementary data were taken from secondary sources. The model was used as a tool to attempt to identify grain legume management options with the potential to make significant contributions to soil fertility. The crop parameters pearl millet grain yield, nitrogen fixation rates, nitrogen harvest index and biomass production were found to be critical in determining system nitrogen inputs and outputs as was the form of residue management. The model indicated that it is extremely difficult to manage grain legumes in dryland environments in ways that lead to consistent increases in pearl millet grain yields, measurable against season-to-season variation due to other factors. Several of the options for improved legume management conflict strongly with farmers' risk-avoidance strategies and their tendency to invest preferentially in off-farm activities in an environment where livelihoods have diversified considerably away from agriculture. Potential routes for increasing grain legume contributions to soil fertility in dryland areas are discussed.

Erythrophagocytosis in the Liver in Hemolytic Anemias

1968 ◽  
Vol 26 ◽  
pp. 184-185
Author(s):  
O. T. Minick ◽  
E. Orfei ◽  
F. Volini ◽  
G. Kent
Keyword(s):  
Acid Phosphatase ◽  
Oxidative Damage ◽  
Phosphatase Activity ◽  
Kupffer Cells ◽  
Acid Phosphatase Activity ◽  
Common Type ◽  
Red Cell ◽  
Cell Fragments ◽  
Reticulo Endothelial System ◽  
Important Site

Hemolytic anemias were produced in rats by administering phenylhydrazine or anti-erythrocytic (rooster) serum, the latter having agglutinin and hemolysin titers exceeding 1:1000.Following administration of phenylhydrazine, the erythrocytes undergo oxidative damage and are removed from the circulation by the cells of the reticulo-endothelial system, predominantly by the spleen. With increasing dosage or if animals are splenectomized, the Kupffer cells become an important site of sequestration and are greatly hypertrophied. Whole red cells are the most common type engulfed; they are broken down in digestive vacuoles, as shown by the presence of acid phosphatase activity (Fig. 1). Heinz body material and membranes persist longer than native hemoglobin. With larger doses of phenylhydrazine, erythrocytes undergo intravascular fragmentation, and the particles phagocytized are now mainly red cell fragments of varying sizes (Fig. 2).

Scanning Electron Microscopy of Fish Scales as an Adjunctive Aid in Speciation

1972 ◽  
Vol 30 ◽  
pp. 394-395
Author(s):  
Edward D. DeLamater ◽  
Walter R. Courtenay ◽  
Cecil Whitaker
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Lateral Line ◽  
Species Differences ◽  
Fish Scale ◽  
Fish Scales ◽  
Anterior Border ◽  
The University ◽  
Multiple Holes ◽  
Scanning Electron

Comparative scanning electron microscopy studies of fish scales of different orders, families, genera and species within genera have demonstrated differences which warrant elaboration. These differences in detail appear to be sufficient to act as “fingerprints”, at least, for family differences. To date, the lateral line scales have been primarily studied. These demonstrate differences in the lateral line canals; the pattern of ridging with or without secondary protuberances along the edges; the pattern of spines or their absence on the anterior border of the scales; the presence or absence of single or multiple holes on the ventral and dorsal sides of the lateral line canal covers. The distances between the ridges in the pattern appear likewise to be important.A statement of fish scale structure and a comparison of family and species differences will be presented.The authors wish to thank Dr. Donald Marzalek and Mr. Wallace Charm of the Marine and Atmospheric Laboratory of the University of Miami and Dr. Sheldon Moll and Dr. Richard Turnage of AMR for their exhaustive help in these preliminary studies.

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