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Video Observations (video + observation)
Selected AbstractsEffects of Circadian Regulation and Rest,Activity State on Spontaneous Seizures in a Rat Model of Limbic EpilepsyEPILEPSIA, Issue 5 2000Mark Quigg Summary: Purpose: Circadian regulation via the suprachiasmatic nuclei and rest,activity state may influence expression of limbic seizures. Methods: Male rats (n = 14) were made epileptic by electrical stimulation of the hippocampus, causing limbic status epilepticus and subsequent seizures. We monitored seizures with intrahippocampal electrodes in 12,12-h light/dark (LD) cycles and in continuous dark (DD). We used radiotelemetry monitoring of activity to measure state and body temperature to determine circadian phase. Cosinor analysis and ,2 tests determined whether seizures occurred rhythmically when plotted by phase. State was defined as inactive or active in 10-min epochs based on whether activity count was below or above a cut-off value validated from video observation. Results: In LD, the peak seizure occurrence was 14:59 h after circadian temperature peak (95% confidence limit, 13:37,16:19). Phasic seizure occurrence persisted in DD for 14:05 (12:31,15:38), p < 0.0001, against uniform mean distribution. In LD, 14,787 epochs contained 1,268 seizures; seizures preferentially occurred during inactive epochs (965 observed, 878 expected in proportion to the overall distribution of inactive versus active epochs; p < 0.001). In DD, 20,664 epochs contained 1,609 seizures; seizures had no preferential occurrence by state (999 observed, 1,025 expected; p = 0.16). Conclusions: Limbic seizures occurred with an endogenous circadian rhythm. Seizures preferentially struck during inactivity during entrainment to the light,dark cycle. [source] Comparative morphology and evolutionary pathways of the mouthparts in spore-feeding Staphylinoidea (Coleoptera)ACTA ZOOLOGICA, Issue 3 2003Oliver Betz Abstract This study surveys the external morphology of the mouthparts in the guild of spore-feeders among the coleopterous superfamily Staphylinoidea, evaluating the influence of different phylogenetic and ecological starting points on the formation of their mouthparts. Our emphasis is on a scanning electron microscope analysis (SEM) of the involved trophic structures in spore-feeding larvae and adults of the Ptiliidae, Leiodidae and Staphylinidae, describing the fine structure of their main functional elements. Functionally, mouthpart structures resemble brushes, brooms, combs, rakes, rasps, excavators, knives, thorns, cram-brushes, bristle troughs, blocks and differently structured grinding surfaces. Their different involvement in the various aspects of the feeding process (i.e. food gathering, transporting, channelling and grinding) is deduced from our SEM analyses plus direct video observations. We infer five different patterns of food transport and processing, discriminating adults of ptiliids, leiodids plus staphylinids (excluding some aleocharines), several aleocharine staphylinids, and the larvae of leiodids and staphylinids. The structural diversity of the mouthparts increases in the order from (1) Ptiliidae, (2) Leiodidae towards (3) Staphylinidae, reflecting the increasing systematic and ecological diversity of these groups. Comparisons with non-spore-feeders show that among major lineages of staphylinoids, shifts from general microphagy to sporophagy are not necessarily constrained by, nor strongly reflected in, mouthpart morphology. Nevertheless, in several of these lineages the organs of food intake and grinding have experienced particular fine-structural modifications, which have undergone convergent evolution, probably in response to specialized mycophagy such as spore-feeding. These modifications involve advanced galeal rakes, galeal or lacinial ,spore brushes' with arrays of stout bristles, reinforced obliquely ventrad orientated prosthecal lobes and the differentiations of the molar grinding surfaces into stout teeth or tubercles. In addition, several staphylinids of the tachyporine and oxyteline groups with reduced mandibular molae have evolved secondary trituration surfaces, which in some aleocharines are paralleled by considerable re-constructions of the labium,hypopharynx. [source] The beginning heights and light curves of high-altitude meteorsMETEORITICS & PLANETARY SCIENCE, Issue 9 2006Pavel Koten During the recent Leonid meteor storms, as well as within the regular double station video observations of other meteor showers, we recorded 164 meteors with a beginning height above 130 km. We found that beginning heights between 130 and 150 km are quite usual, especially for the Leonid meteor shower. Conversely, meteors with beginning heights above 160 km are very rare even among Leonids. From the meteor light curves, we are able to distinguish two different processes that govern radiation of the meteors at different altitudes. Light curves vary greatly above 130 km and exhibit sudden changes in meteor brightness. Sputtering from the meteoroid surface is the dominating process during this phase of the meteor luminous trajectory. Around 130 km, the process switches to ablation and the light curves become similar to the light curves of standard meteors. The sputtering model was successfully applied to explain the difference in the beginning heights of high-altitude Leonid and Perseid meteors. We show also that this process in connection with high altitude fragmentation could explain the anomalously high beginning heights of several relatively faint meteors. [source] SUPRACENTER: Locating fireball terminal bursts in the atmosphere using seismic arrivalsMETEORITICS & PLANETARY SCIENCE, Issue 9 2004W. N. EDWARDS A computer program, SUPRACENTER, calculates travel times by ray tracing through realistic atmospheres (that include winds) and locates source positions by minimization of travel time residuals. This is analogous to earthquake hypocenter location in the solid Earth but is done through a variably moving medium. Inclusion of realistic atmospheric ray tracing has removed the need for the simplifying assumption of an isotropic atmosphere or an approximation to account for "wind drift." This "drift" is on the order of several km when strong, unidirectional winds are present in the atmosphere at the time of a fireball's occurrence. SUPRACENTER-derived locations of three seismically recorded fireballs: 1) the October 9, 1997 El Paso superbolide; 2) the January 25, 1989 Mt. Adams fireball; and 3) the May 6, 2000 Morávka fireball (with its associated meteorite fall), are consistent with (and, probably, an improvement upon) the locations derived from eyewitness, photographic, and video observations from the respective individual events. If direct acoustic seismic arrivals can be quickly identified for a fireball event, terminal burst locations (and, potentially, trajectory geometry and velocity information) can be quickly derived, aiding any meteorite recovery efforts during the early days after the fall. Potentially, seismic records may yield enough trajectory information to assist in the derivation of orbits for entering projectiles. [source] Comparisons of breeding systems between two sympatric species, Nastanthus spathulatus (Calyceraceae) and Rhodophiala rhodolirion (Amaryllidaceae), in the high Andes of central ChilePLANT SPECIES BIOLOGY, Issue 1 2009PHILIP G. LADD Abstract Alpine vegetation occurs over a wide range of ecological conditions. Thus, the breeding systems of alpine plants are likely to be diverse and vary from one geographical area to another. The reproductive characteristics of Nastanthus spathulatus (Calyceraceae) and Rhodophiala rhodolirion (Amaryllidaceae), species with contrasting floral morphology, were studied in the high Andes of Chile, which has a Mediterranean-type climate. Natural and supplemental open pollination, and cross pollination and self-pollination trials were carried out in the field. Flower visitors were quantified by field and video observations. Both species had high outcrossing properties, and Nastanthus was strongly self-incompatible. Rhodophiala could form some seed by self-pollination, but fruit and seed sets were much lower after self-pollination compared with outcrossing. The phenology and flower/inflorescence forms of these species supported the view that alpine flowers are comparatively long lived and that the floral display contributes to a large proportion of the plant biomass. Rhodophiala was well attended by a native bee species (Megachile sauleyi) that was appropriately sized for efficient pollination. Although no flower visitors were observed on Nastanthus and wind pollination was discarded experimentally, a high proportion of the flowers produced seeds under natural pollination. Therefore, the seed set was not severely pollen limited in these species. Including previously published information, breeding systems are now known for 12 species on this Mediterranean alpine site and current knowledge suggests an emphasis on outcrossing breeding systems. [source] | ||||||||||