5 resultados para Consolidation of the land
em National Center for Biotechnology Information - NCBI
Resumo:
The eggs of the land slug Arion sp. contain a diterpene, miriamin, characterized as a polyoxygenated geranylgeraniol derivative. In bioassays with a coccinellid beetle, Harmonia axyridis, miriamin was shown to be potently antifeedant, indicating that the compound plays a protective role in nature. It is suggested that mucilaginous soil-inhabiting organisms, given their intense exposure to pathogens and predators, may be a rich source of chemical defensive agents.
Resumo:
Service to the state is one of the core principles of the land-grant mission. This concept of service is also fundamental to a significant number of outreach activities in academic health sciences libraries, particularly those libraries affiliated with the public land-grant universities. The Dana Medical Library at the University of Vermont has a lengthy tradition of outreach to health care providers and health care consumers of the State of Vermont. Building on the foundation of the land-grant institution—which grew out of federal legislation introduced in the mid nineteenth century by Justin Morrill, Vermont's congressional representative—the Dana Medical Library has based its outreach activities on its dedication of service to the state in the promotion of healthy citizens through information dissemination in support of health care delivery. Reengineering library services designed to meet the specific information needs of its diverse clientele, partnering with disparate health care organizations, and relying on fees for service to expand its outreach activities, the Dana Medical Library has redefined the concept of health information outreach for the new millennium.
Resumo:
Isotopic age determinations (40Ar/39Ar) and associated magnetic polarity stratigraphy for Casamayoran age fauna at Gran Barranca (Chubut, Argentina) indicate that the Barrancan “subage” of the Casamayoran South American Land Mammal “Age” is late Eocene, 18 to 20 million years younger than hitherto supposed. Correlations of the radioisotopically dated magnetic polarity stratigraphy at Gran Barranca with the Cenozoic geomagnetic polarity time scale indicate that Barrancan faunal levels at the Gran Barranca date to within the magnetochronologic interval from 35.34 to 36.62 megannums (Ma) or 35.69 to 37.60 Ma. This age revision constrains the timing of an adaptive shift in mammalian herbivores toward hypsodonty. Specifically, the appearance of large numbers of hypsodont taxa in South America occurred sometime between 36 and 32 Ma (late Eocene–early Oligocene), at approximately the same time that other biotic and geologic evidence has suggested the Southern high latitudes experienced climatic cooling associated with Antarctic glaciation.
Resumo:
Head trauma leading to concussion and electroconvulsive shock (ECS) in humans causes amnesia for events that occurred shortly before the injury (retrograde amnesia). The present experiment investigated the amnesic effect of lidocaine and ECS in 25 rats trained on a working memory version of the Morris water task. Each day, the escape platform was moved to a new location; learning was evidenced by a decrease in the latency to find the platform from the first to the second trial. "Consolidation" of this newly encoded spatial engram was disrupted by bilateral inactivation of the dorsal hippocampus with 1 microliter of 4% lidocaine applied as soon as possible after the first trial. When trial 2 was given after recovery from the lidocaine (30 min after the injection), a normal decrease in latency indicated that the new engram was not disrupted. When trial 2 was given under the influence of lidocaine (5 min after injection), absence of latency decrease demonstrated both the success of the inactivation and the importance of hippocampus for the task. To examine the role of events immediately after learning, ECS (30 or 100 mA, 50 Hz, 1.2 sec) was applied 0 sec to 45 sec after a single escape to the new platform location. A 2-h delay between ECS and trial 2 allowed the effects of ECS to dissipate. ECS applied 45 sec or 30 sec after trial 1 caused no retrograde amnesia: escape latencies on trial 2 were the same as in control rats. However, ECS applied 0 sec or 15 sec after trial 1 induced clear retrograde amnesia: escape latencies on trial 2 were no shorter than on trial 1. It is concluded that the consolidation of a newly formed memory for spatial location can only be disrupted by ECS within 30 sec after learning.