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Full-Text Articles in Life Sciences

Die Konsequenzen Eines Lebens Im Druckbehälter. Biotheoretische Implikationen Der Organisation Pflanzlicher Organismen [The Consequences Of Living In A Pressure Pot. Biotheoretical Implications Of The Organismic Architecture Of Plants], Winfried Peters, Hubert Felle Jun 1992

Die Konsequenzen Eines Lebens Im Druckbehälter. Biotheoretische Implikationen Der Organisation Pflanzlicher Organismen [The Consequences Of Living In A Pressure Pot. Biotheoretical Implications Of The Organismic Architecture Of Plants], Winfried Peters, Hubert Felle

Winfried S. Peters

Die Betrachtung der sich aus der zellulären Osmo- und Druckregulation ergebenden konstruktiven Zwänge erlaubt es, invariante Eigenschaften makroskopischer Pflanzen abzuleiten. Sessilität wird als grundsätzlich unumgänglich erkannt; Autotrophie als zwangsläufige Ernährungsform kann nur durch Parasitismus oder Beteiligung an Symbiosen umgangen werden. Hieraus ergibt sich die Antwort auf die Frage nach dem “Unterschied” zwischen Tieren und Pflanzen: die Bildung clonarer Kolonien (Metapopulationen) kann bei sessilen Organismen besonders plausibel begründet werden, zumal, wenn diese autotroph leben. Sessilität stellt bei Tieren eine Option, bei makroskopischen Pflanzen aber eine Notwendigkeit dar. Das Vorherrschen des Konstruktionstyps “Metapopulation” bei Pflanzen ist damit vorgezeichnet; dies ist letztlich eine …


Capsaicin Effects On Consumption Of Food By Cedar Waxwings And House Finches.­, Donald Norman, Russell Mason, Larry Clark Jan 1992

Capsaicin Effects On Consumption Of Food By Cedar Waxwings And House Finches.­, Donald Norman, Russell Mason, Larry Clark

Larry Clark

Capsaicin effects on consumption of food by Cedar Waxwings and House Finches.­ Capsaicinoids (e.g., N-vanillyl-n-nonamide. norcapsaicin, nordihydrocapsaicin, capsaicin, dihydrocapsaicin, homocapsaicin, homodihydrocapsaicin; Hoffman 1983) are aromatic am­ ides and the pungent principles in Capsicum peppers. Although these substances are strong chemical irritants for most mammals (e.g.. Rozin et a!. 1979), the available data suggest that they are inoffensive to some birds. For example. European Starlings (Sturn us vulgaris) and Rock Doves (Columba Iivia) are unresponsive to these compounds, even when con­ centrations greatly exceed those which mammals avoid (Szolcsanyi et al. 1986; Mason et a!.. in press).


Taxonomic Differences Between Birds And Mammals In Their Responses To Chemical Irritants, Russell Mason, Larry Clark, Pankaj Shah Jan 1992

Taxonomic Differences Between Birds And Mammals In Their Responses To Chemical Irritants, Russell Mason, Larry Clark, Pankaj Shah

Larry Clark

Ninety-five products are registered with the u.s. Environmental Pro­ tection Agency as bird damage control chemicals, but 38 (40%) are non­ lethal chemical repellents (Eschen and Schafer, 1986). Of these products, the active ingredients in 27 (71%) are methiocarb (a physiologic repellent that acts through food avoidance learning) or polybutene (a tactile repel­ lent). In general, chemical repellents are effective either because of aversive sensory effects (irritation), or because of post-ingestional ma­ laise (sickness). If the former, then chemicals are usually stimulants of trigeminal pain receptors (i.e., undifferentiated free nerve endings) in the nose, mouth, and eyes (Mason and Otis, …


Effects Of The Argentine Ant On Arthropod Fauna Of Hawaiian High-Elevation Shrubland, F Cole, Arthur Madeiros, Lloyd Loope, William Zuehlke Dec 1991

Effects Of The Argentine Ant On Arthropod Fauna Of Hawaiian High-Elevation Shrubland, F Cole, Arthur Madeiros, Lloyd Loope, William Zuehlke

F. Russell Cole

Human-caused biological invasions by an alien species are a worldwide phenomenon. They are particularly significant on isolated oceanic islands and represent a serious threat to endemic biota. The Argentine ant (Iridomyrmex humilis) has become established in portions of the high-elevation shrubland of Haleakala National Park, Maui, Hawaii, over the past 25 yr. This ecosystem lacks native ants but possesses many locally endemic and rare anthropod species. Pitfall trapping and under-rock surveys were conducted to determine the effects of I. humilis on the local arthropod fauna. More than 180 taxa were sampled, mostly Arthropoda. Presence of the Argentine ant is associated …