Blockage of tropoelastin secretion by monensin represses tropoelastin synthesis at a pretranslational level in rat smooth muscle cells.

The blockage of protein secretion in the R22 cultured rat aortic smooth muscle cell strain with monensin repressed tropoelastin gene expression at the mRNA level by ca. 50-fold as measured by biosynthetic pulse-labeling, in vitro translation, and hybridization with a tropoelastin genomic DNA probe. These results suggest that tropoelastin gene expression is autoregulated, and they represent the first reported effect of monensin on gene expression.     

Top-down and bottom-up regulation of herbivores: Spodoptera frugiperda turns tables on endophyte-mediated plant defence and virulence of an entomopathogenic nematode

Abstract.  1. The fungus Neotyphodium lolii forms a symbiotic relationship with its grass host Lolium perenne (perennial ryegrass). The fungus benefits from access to plant nutrients and photosynthate, whereas the plant benefits from acquired chemical defence against herbivory.
2. This study examined the potential for endophyte-mediated plant defences to influence interactions between fall armyworm Spodoptera frugiperda , and the entomopathogenic nematode Steinernema carpocapsae and clarified biological mechanisms underlying the observations made.
3. In laboratory and greenhouse experiments, S. frugiperda larvae were fed endophytic or non-endophytic L. perenne then exposed to S. carpocapsae or injected with the nematodes' symbiotic bacteria Xenorhabdus nematophila .
4. In all instances, S. frugiperda larvae fed endophyte-infected grass suffered significantly lower mortality than those fed non-endophytic plants. Although larvae fed endophyte-infected grass often had significantly lower biomass than those fed uninfected grass, these differences did not account for altered susceptibility to S. carpocapsae .
5. Endophyte-mediated reductions in herbivore susceptibility to the nematode pathogen represent a herbivore adaptation that effectively turns the tables on both plant and natural enemy by reducing the virulence of the nematodes' symbiotic bacteria while expanding the temporal window of herbivory.     

Dream Imagery and Emotion.

The relationship between prominent visual imagery and emotion within dreams was investigated in relation to E. Hartmann's (1996) contextualizing image (CI) theory and M. Seligman and A. Yellen's (1987) dual imagery theory. Fifty-nine students recorded dreams over a 2-week period and submitted 115 dreams for analysis. Participants recorded ratings of emotion type and emotion intensity in each scene. Prominent visual images were identified and scored for intensity and detail by independent judges. As hypothesized from Hartmann's theory, there was a significant positive relationship between CI intensity and emotion intensity in the CI scene, emotion intensity generally peaked in the CI scene, and dreams containing a CI had higher overall ratings of emotion intensity than non-CI dreams. The result for the correlation of detail of prominent imagery with emotion was inconclusive, with a low positive correlation across CI scenes. This raises the possibility that the CI is not a unitary construct. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Parasites, diseases and health status of sympatric populations of sambar deer and white-tailed deer in Florida

From December 1983 to December 1984 a study on parasites, diseases and health status was conducted on sympatric populations of sambar deer (Cervus unicolor) and white-tailed deer (Odocoileus virginianus) from St. Vincent Island, Franklin County, Florida. Ten sambar and six white-tailed deer were examined. White-tailed deer had antibodies to epizootic hemorrhagic disease virus and bluetongue virus. Serologic tests for antibodies to the etiologic agents of bovine virus diarrhea, infectious bovine rhinotracheitis, vesicular stomatitis, parainfluenza 3, brucellosis, and leptospirosis were negative in both species of deer. White-tailed deer harbored 19 species of parasites; all were typical of the parasite fauna of this species in coastal regions of the southeastern United States. Sambar deer harbored 13 species of parasites, which apparently were derived largely from white-tailed deer. The only exception was Dermacentor variabilis which occurs frequently on wild swine on the island. The general health status of sambar deer appeared to be better than that of white-tailed deer. This was hypothesized to result from the sambar deer's utilization of food resources unavailable or unacceptable to white-tailed deer and to the absence and/or lower frequency of certain pathogens in sambar deer.     

Reproductive strategies,body size,and encephalization in primate evolution

In order to understand fully the generally high level of encephalization observed in living primates, we must determine why early primates exhibited moderately large relative brain sizes compared to their early Tertiary contemporaries. The relatively high degree of encephalization in early primates may be related at least in part to the fact that they were highly unusualamong mammals in combining a small body size with a strongly precocial reporductive strategy. Other small, precocial mammals also exhibit moderately high levels of encephalization; but primates appear to have been truly uniquein being the only such small-sized and highly precocial group to give rise to extensive radiations of larger descendants. This is a key element in understanding primate brain evolution, because the initial “head start” of the early primates was translated up to larger sizes in descendants. The possible relationships among encephalization, precociality, small size, and arboreality are discussed, particularly in light of recent debates concerning the validity of the superorder Archonta. This work emphasizes that we need to consider relative brain size as but one element in a complex synergistic network of morphological and life-history features.     

PHYSIOLOGICAL MODIFICATIONS RELATED TO DENSITY INCREASE IN PERIPHYTIC ASSEMBLAGES 1

Periphytic communities in running waters were examined as they developed on granite rocks, concrete balls and glass slides. At equivalent cell densities, no differences in pigment concentrations, species diversity or production levels were found among the different substrata examined. Development of the assemblage appeared to result from the elongation of short algal filaments which had initially settled on the surface. As these communities matured, a distinct canopy and understory developed. Cellular metabolisms were comparable among the communities. In the understory of the communities, even though the cellular content of chl a and b did not differ, chl c and carotenoid pigment concentrations were higher than those in the over-story. Bicarbonate assimilation of Tabellaria fenestrata (Lyng.) Külz. and Eunotia pectinalisi var. pectinalis (O. F. Müll?) Rabh. was higher than that of the more abundant Tabellaria flocculosa (Roth.)Kütz. var. flocculosa IV (sensu Koppen) at both high and low cell densities. This probably reflects a seasonal succession of colonizing species. Glucose assimilation appeared to be mainly attributable to bacterial activity, and algal cells of the upper layer were less active than those of the bottom. The small amount of glucose that was incorporated by the algal cells was probably absorbed passively since its amount was in direct proportion to cell volumes.