Über den Einbau14C-markierter Aminosäuren in Zellkernfraktionen aus Meerschweinchenleberzellenin vitro

Summary The incorporation of¹⁴C-amino acids into ribonucleoproteid particles obtained by differential centrifugation of mechanically disintegrated liver cell nuclei was demonstratedin vitro. Nuclear supernatant revealed also very remarkable incorporation.     

The effect of sodium nitrite on red cell GSH

Zusammenfassung Bei der Nachuntersuchung der Nitritwirkung auf das GSH der unversehrten Erythrocyten konnte nur ein geringfügiger Effekt festgestellt werden. Die früher mitgeteilte totale Zerstörung der GSH wurde auf einen Artefakt zurückgeführt, der während der Eiweissfällung mit Metaphosphorsäure auftrat.

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Supported in part by U.S.P.H.S. Grants H-5313 and H-5292.     

Phototactic choice between two white light sources of various intensity in blowfly,Calliphora erythrocephala Meig.

Zusammenfassung Die Proportion der Auswahl des variablen Lichtes durch die Population der Schmeissfliege,Calliphora erythrocephala Meig. im LabyrinthY, beim Standard 900 Lux, wächst zusammen mit der relativen Lichtstärke, wobei sie sich bei grösseren Lichtstärken dem Maximalwert von etwa 0.60 zu nähern scheint.     

The effect of some neurohormones on the heart rate of spiders

Résumé Les auteurs ont étudié l'effet de l'adrénaline et de l'acétylocholine sur le rythme du cur chez l'araignéeTegenaria atrica C. L. Koch. L'enregistrement s'est fait au moyen de l'électroencephalographe. L'injection de l'adrénaline provoquait l'accélération du rythme du cur, l'acétylocholine — son ralentissement.     

Electronic tagging and population structure of Atlantic bluefin tuna

Electronic tags that archive or transmit stored data to satellites have advanced the mapping of habitats used by highly migratory fish in pelagic ecosystems. Here we report on the electronic tagging of 772 Atlantic bluefin tuna in the western Atlantic Ocean in an effort to identify population structure. Reporting electronic tags provided accurate location data that show the extensive migrations of individual fish (n = 330). Geoposition data delineate two populations, one using spawning grounds in the Gulf of Mexico and another from the Mediterranean Sea. Transatlantic movements of western-tagged bluefin tuna reveal site fidelity to known spawning areas in the Mediterranean Sea. Bluefin tuna that occupy western spawning grounds move to central and eastern Atlantic foraging grounds. Our results are consistent with two populations of bluefin tuna with distinct spawning areas that overlap on North Atlantic foraging grounds. Electronic tagging locations, when combined with US pelagic longline observer and logbook catch data, identify hot spots for spawning bluefin tuna in the northern slope waters of the Gulf of Mexico. Restrictions on the time and area where longlining occurs would reduce incidental catch mortalities on western spawning grounds.     

Neon isotopes constrain convection and volatile origin in the Earth's mantle

Identifying the origin of primordial volatiles in the Earth's mantle provides a critical test between models that advocate magma-ocean equilibration with an early massive solar-nebula atmosphere and those that require subduction of volatiles implanted in late accreting material. Here we show that neon isotopes in the convecting mantle, resolved in magmatic CO2 well gases, are consistent with a volatile source related to solar corpuscular irradiation of accreting material. This contrasts with recent results that indicated a solar-nebula origin for neon in mantle plume material, which is thought to be sampling the deep mantle. Neon isotope heterogeneity in different mantle sources suggests that models in which the plume source supplies the convecting mantle with its volatile inventory require revision. Although higher than accepted noble gas concentrations in the convecting mantle may reduce the need for a deep mantle volatile flux, any such flux must be dominated by the neon (and helium) isotopic signature of late accreting material.