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Distribution Of Plants With Extrafloral Nectaries In Temperate Communities, Kathleen H. Keeler
Distribution Of Plants With Extrafloral Nectaries In Temperate Communities, Kathleen H. Keeler
School of Biological Sciences: Faculty Publications
The abundance of plants with extrafloral nectaries was determined for a series of temperate habitats in Nebraska. Mean cover of plants with extrafloral nectaries was 1.3% in riparian forest understory, 1.8% in virgin deciduous forest understory, 0.0% in tall-grass prairie, and 8.3% in sandhill prairie. Sandhills prairie contained distinct communities with different mean cover of plants with extrafloral nectaries and showed seasonal changes in nectary activity. Cover of plants with extrafloral nectaries was compared to ant abundance, plant species diversity, rainfall and frost-free season: the first two showed highly significant correlations with mean cover of extrafloral nectaries.
The Flora And Sandhills Prairie Communities Of Arapaho Prairie, Arthur County, Nebraska, Kathleen H. Keeler, A. T. Harrison, L.S. Vescio
The Flora And Sandhills Prairie Communities Of Arapaho Prairie, Arthur County, Nebraska, Kathleen H. Keeler, A. T. Harrison, L.S. Vescio
School of Biological Sciences: Faculty Publications
The Arapaho Prairie is a 526-hectare (two-section) tract of upland Sandhills prairie located approximately nine miles southwest of the town of Arthur in Arthur Co., Nebraska (Sec. 31, 32 T18N R39W). The Prairie is at the extreme southwest edge of the 52,000-km2 Nebraska Sandhills (see Kaul 1975) and is floristically and ecologically typical of the slightly drier, western part of this vegetation type. Sandhills prairie which stretches across much of north central Nebraska is a unique type of "mixed" grassland (Pool 1914, Rydberg 1931, Tolstead 1942, Weaver 1965) created by impact of the dry, continental climate on the extensive …
The Extrafloral Nectaries Of Ipomoea Leptophylla (Convolvulaceae), Kathleen H. Keeler
The Extrafloral Nectaries Of Ipomoea Leptophylla (Convolvulaceae), Kathleen H. Keeler
School of Biological Sciences: Faculty Publications
Ipomoea leptophylla Torr. (Convolvulaceae) is a sprawling dry-site morning glory with two types of extrafloral nectaries: foliar nectaries and nectaries on the outside of the sepals. Both are shown to greatly increase insect visitation to the plant. Ants visiting sepal-surface nectaries significantly decrease flower damage caused by grasshoppers and seed losses caused by bruchids. These results are similar to those for I. carnea and other plants whose extrafloral nectary-ant interactions have been studied, but differ in detail. This is the first demonstration of antiherbivore defense of a prairie plant by nectary visitors.
Absolute Requirement Of Glucocorticoid For Expression Of The Casein Gene In The Presence Of Prolactin, Ranjan Ganguly, Nivedita Ganguly, Nozer M. Mehta, M. R. Banerjee
Absolute Requirement Of Glucocorticoid For Expression Of The Casein Gene In The Presence Of Prolactin, Ranjan Ganguly, Nivedita Ganguly, Nozer M. Mehta, M. R. Banerjee
School of Biological Sciences: Faculty Publications
Second thoracic mammary glands of immature BALB/c female mice were stimulated to pregnancy-like lobuloalveolar (LA) development after 6 days of incubation in a corticosteroid-free step I culture medium containing insulin, prolactin, estradiol, progesterone, and growth hormone. A low basal level (0.0009%) of casein mRNA (mRNAcsn) sequences was detectable in the LA glands by a specific cDNA probe. Subsequent incubation of the LA glands for 3 days in medium containing insulin and prolactin or insulin and cortisol failed to elicit mRNAcsn above the basal level, indicating that neither prolactin nor cortisol alone can support casein gene expression. However, …
Inhibition Of Biological Activity Of Multiplication-Stimulating Activity By Binding To Its Carrier Protein, Daniel J. Knauer, Gary L. Smith
Inhibition Of Biological Activity Of Multiplication-Stimulating Activity By Binding To Its Carrier Protein, Daniel J. Knauer, Gary L. Smith
School of Biological Sciences: Faculty Publications
Multiplication-stimulating activity (MSA) produced by Buffalo rat liver cells (BRL-3A) in culture is related to the somatomedin family of growth regulatory polypeptides. MSA will stimulate glucose transport and DNA synthesis in normal chicken embryo fibroblasts (CIEF) at concentrations of 10-200 ng/ml. MSA found in BRL-3A-conditioned medium, like the somatomedins in serum, does not exist as the free hormone but is' bound to a specific high molecular weight carrier protein. In this report we demonstrate that purified MSA carrier protein (MCP) inhibits the biological activity of MSA on CEF as measured by the stimulation of glucose transport and DNA synthesis. In …
Quantitative Demonstration Of Cell Surface Involvement In A Plant-Animal Symbiosis: Lectin Inhibition Of Reassociation, R. H. Meints, Rosevelt L. Pardy
Quantitative Demonstration Of Cell Surface Involvement In A Plant-Animal Symbiosis: Lectin Inhibition Of Reassociation, R. H. Meints, Rosevelt L. Pardy
School of Biological Sciences: Faculty Publications
The freshwater hydra, Hydra viridis is normally associated with Chlorella-like, algal symbionts which inhabit the host's digestive cells. Under experimental conditions bleached hydra will reassociate with algae harvested from green hydra, but not from our cultures of wild type Chlorella or strain NC64A which when originally isolated from Paramecium bursaria was symbiotically competent. Because of its demonstrated selectivity, the reassociation process is hypothesized to involve a recognition interface whose active participants are the algae cell wall and the digestive cell membrane. The data presented here confirm the hypothesis and suggest some potential molecular characteristics of the interacting partners. Concanavalin …
Quantitative Demonstration Of Cell Surface Involvement In A Plant-Animal Symbiosis: Lectin Inhibition Of Reassociation, R. H. Meints, R. L. Pardy
Quantitative Demonstration Of Cell Surface Involvement In A Plant-Animal Symbiosis: Lectin Inhibition Of Reassociation, R. H. Meints, R. L. Pardy
School of Biological Sciences: Faculty Publications
The freshwater hydra, Hydra viridis is normally associated with Chlorella-like, algal symbionts which inhabit the host's digestive cells. Under experimental conditions bleached hydra will reassociate with algae harvested from green hydra, but not from our cultures of wild type Chlorella or strain NC64A which when originally isolated from Paramecium bursaria was symbiotically competent. Because of its demonstrated selectivity, the reassociation process is hypothesized to involve a recognition interface whose active participants are the algae cell wall and the digestive cell membrane. The data presented here confirm the hypothesis and suggest some potential molecular characteristics of the interacting …