George Armytage Rounsefell 1905-1976

Remembrances and reflections on the life and career of George Armytage Rounsefell

Concepts and action : where does the embodiment debate leave us?

The behavioural evidence of sensorimotor activity during conceptual processing, along with that from neurological research, ignited the debate around the extent to which concept representations are embodied or amodal. Such evidence continues to fuel the debate but it is open to interpretation as being consistent with a variety of the theoretical positions and so it is possible that further, similar evidence may not lead to its resolution. In this paper we propose that independent value accrues from following this line of research through the enhanced understanding of the factors that influence agents’ conceptual processing of action and how this interacts with the agent’s goals in real environments. This approach is in line with broad principles of embodied cognition and is worthy of pursuit regardless of what the results may (or may not) tell us about conceptual representation

Experimental Evaluation of Potential Effects of Habitat Size and Presence of Conspecifics on Habitat Association by Young-of-the-Year Red Snapper

The potential effects of habitat size and the presence of larger conspecifics on habitat association by young-of-the-year (YOY) red snapper Lutjanus campechanus was evaluated in 2.2 m3 laboratory tanks. Our results indicate that YOY red snapper have a strong affinity for structure, which ranged in these experiments from open-sand bottom to concrete-block, artificial reef-like habitats. Mean distance of YOY red snapper from the blocks decreased significantly and the time spent near the structures increased significantly as the size of the habitat increased. However, when larger subadult snapper were present, both distances to the reefs and time that YOY spent near them was significantly reduced, as the larger conspecifics actively defended the structure from occupation by YOY. If similar interactions occur in situ, small snapper that attempt to move onto reefs from the shrimping grounds that serve as nursery areas for juveniles may be subject to predation pressures by piscivorous fishes inhabiting the reefs. Finally, in experiments that used both larger conspecifics and alternate prey similar in size to the YOY red snapper, results indicated that larger snapper preferentially consumed the alternate prey and did not cannibalize the YOY red snapper. Nevertheless, YOY still were not permitted to occupy the artificial reef habitats in any experiments when larger conspecifics were present in the tanks. If results of these experiments are exportable to the field, they may partially explain the observation that YOY red snapper in natural populations are more often found in shallower water on shrimping grounds, whereas larger juveniles begin to recruit to the offshore reefs once they have obtained a size refuge. If additional studies conclude that YOY red snapper are attracted to larger or more complex habitats but avoid these structures because of pressure from larger juveniles and/or adults, the strategy of continued placement of artificial reefs large enough to attract adult snapper and other piscivores in and near the inshore shrimping grounds should be reassessed

Feeding Periodicity and Prey Habitat Preference of Red Snapper, Lutjanus campechanus (Poey, 1860) on Alabama Artificial Reefs

Conclusive understanding of the role temperate artificial reefs play in the trophic dynamics of Lutjanus campechanus (Poey, 1860) is limited. Thus, diel feeding habits of red snapper on artificial reefs were examined using gut fullness, diet composition, and prey habitat preferences. Red snapper were collected by hook and line from artificial reefs off Alabama in July and Aug. 2000. Examination of stomach contents found red snapper feeding upon fish, demersal crustaceans, and pelagic zooplankton. Although other studies suggest that lutjanids primarily feed nocturnally, red snapper in this study fed throughout the day and night. Significant differences in gut fullness were found between 2-hr time intervals; however, no obvious pattern in feeding periodicity was evident. Although fish was the largest diet component by weight for both day and night during diel sampling, examination of prey habitat preferences indicate that red snapper fed on more water-column organisms during the day and more sand- or mud-associated organisms at night. Based on our interpretation of these results, we hypothesize that red snapper reside above the reefs during the day, opportunistically feeding mostly upon water-column-associated organisms and some benthic prey. At night they may move away from the reef to consume nocturnally active fishes and benthic crustaceans

Age, Growth, Diet, and Reproductive Biology of the Tripletail, Lobotes surinamensis, From the North-Central Gulf of Mexico

Tripletail, Lobotes surinamensis, are migratory fish that occur worldwide in warm seas, including the Gulf of Mexico and Caribbean. In the north-central Gulf of Mexico, tripletail support small recreational and commercial fisheries from April to Oct. and are commonly caught in bays and estuaries. Few studies have evaluated the life history and biological characteristics of tripletail; therefore, the objective of this study was to examine the age and growth, reproductive biology, and diet of tripletail caught off coastal Alabama. Our primary goal was to use life history information to determine. a minimum size limit for harvest. A secondary goal was to compare the results of our study with those of previous tripletail studies. A total of 119 specimens, ranging in size from 293- to 763-mm total length (TL), were collected from recreational anglers and from a wholesale seafood dealer between May 1998 and Aug. 2000. Female specimens were significantly longer and heavier than males. Total length varied greatly with age, although significant overlap in lengths was observed among ages. Age ranged from 0.87 to 4.09 yr. No male was older than 3.15 yr of age, whereas five females were estimated to be more than 4 yr old. Fifty percent of females reached sexual maturity by 494- to 594-mm TL and approximately 1 to 2 yr of age. All males greater than 380 mm were sexually mature. Diets were composed primarily of penaeid shrimps, various pelagic fish species, and portunid crabs, with the proportion of fish consumed increasing with tripletail length. On the basis of the results of this study as well as previous research on the life history and population dynamics of tripletail, the state of Alabama implemented a 406 mm (16 inch) minimum size limit for this species. This size limit is below the female size at 50% maturity (19.5-23.5 inch) and should be increased if large increases in fishing pressure occur

Movement of Red Snapper, Lutjanus campechanus, in the North Central Gulf of Mexico: Potential Effects of Hurricanes

Site fidelity and movement of red snapper, Lutjanus campechanus, were estimated from a tagging study conducted off the coast of Alabama from March 1995 to January 1997. Red snapper were caught using rod and reel over nine artificial reef sites, with three reefs each located at 21-m, 27-m, and 32-m depths. During the study, 1,604 fish were tagged, and 174 recaptures were made of 167 individuals. On 4 October 1995, the eye of Hurricane Opal passed within 40 km of the artificial reef sites. When recaptures were stratified according to whether or not they were at liberty during Opal, storm effect was the most significant factor in predicting the likelihood of movement and magnitude of movement by tagged red snapper. Eighty percent of recaptured red snapper that were not at liberty during Opal were recaptured at their site of release. Fish that were at liberty during Opal, however, had a significantly higher likelihood of movement away from their site of release (P \u3c 0.001). These fish also moved significantly further than those that were not at liberty during Opal (P \u3c 0.001). Fish that were at liberty during Opal moved a mean distance (± SE) of 32.6 km (± 6.81), compared to a mean distance (± SE) of 2.5 km (± 1.10) for fish that were tagged and recaptured before Opal, and a mean distance (± SE) of 1.7 km (± 0.43) for fish that were tagged and recaptured after Opal. Heretofore, it has generally been accepted that adult red snapper demonstrate strong site fidelity and genetic homogeneity in the stock was hypothesized to result from larval drift or due to historic mixing on longer time scales. This study documents movement of adult red snapper on spatial scales that would facilitate stock mixing and implicates large-scale climatic events, such as hurricanes, as important factors in stock mixing dynamics

Cerebral hierarchies: predictive processing, precision and the pulvinar

This paper considers neuronal architectures from a computational perspective and asks what aspects of neuroanatomy and neurophysiology can be disclosed by the nature of neuronal computations? In particular, we extend current formulations of the brain as an organ of inference—based upon hierarchical predictive coding—and consider how these inferences are orchestrated. In other words, what would the brain require to dynamically coordinate and contextualize its message passing to optimize its computational goals? The answer that emerges rests on the delicate (modulatory) gain control of neuronal populations that select and coordinate (prediction error) signals that ascend cortical hierarchies. This is important because it speaks to a hierarchical anatomy of extrinsic (between region) connections that form two distinct classes, namely a class of driving (first-order) connections that are concerned with encoding the content of neuronal representations and a class of modulatory (second-order) connections that establish context—in the form of the salience or precision ascribed to content. We explore the implications of this distinction from a formal perspective (using simulations of feature–ground segregation) and consider the neurobiological substrates of the ensuing precision-engineered dynamics, with a special focus on the pulvinar and attention

Effect of Surface Mass on Roof Thermal Performance

The roof of a building is exposed to the most severe environment that is experienced by any component of a building envelope. Diurnal peak surface temperatures of 140 to 185 °F are not uncommon. The addition of thermal mass to the exterior surface of the roof should lessen the severity of the environment that is experienced by the roof membrane and the roof insulation. The exterior mass should result in attenuation both of temperature extremes and of heat flux variations. It also may result in lowered net heat flow through the roof. This paper presents some results of a combined experimental and analytical study to quantify the effects of surface mass. Measurements were made on roof test panels that were exposed to the weather of eastern Tennessee. The test panels consisted of glass fiber insulation with a modified bitumen membrane. Experiments were conducted on a bare panel and on a panels that were loaded with either concrete pavers or aggregates. A heat transfer model for the bare panel and the panel with concrete pavers was developed to calculate the internal temperatures and heat fluxes using measured indoor and ambient conditions. The model was validated by comparing its predictions with measured values. Following validation, the model was used to perform a parametric study of the effects of various levels of surface mass