Can zoosporic true fungi grow or survive in extreme or stressful environments?

Zoosporic true fungi are thought to be ubiquitous in many ecosystems, especially in cool, moist soils and freshwater habitats which are rich in organic matter. However, some of the habitats where these fungi are found may periodically experience extreme conditions, such as soils in extremely dry, hot and cold climates, acidic and alkaline soils, polluted rivers, anaerobic soil and water, saline soil and water, periglacial soils, oligotrophic soils, tree canopies and hydrothermal vents. It is clear that many ecotypes of zoosporic true fungi have indeed adapted to extreme or stressful environmental conditions. This conclusion is supported by studies in both the field and in the laboratory. Therefore, in our opinion, at least some true zoosporic fungi can be considered to be extremophiles.     

Patterns of reproduction and development of selected resident teleosts of Florida salt marshes

A wide variety of teleost fishes occur in tidal marshes of Atlantic and Gulf coasts of Florida, few of which breed in these habitats or remain there for extended periods of time. A significant fraction of teleosts that do so are members of one of five families. Eleven representative species belonging to these families, whose reproduction and development are considered here, include: Adinia xenica, Fundulus confluentus, F. grandis and F. similis (Fundulidae); Cyprinodon variegatus, Floridichthys carpio and Jordanella floridae (Cyprinodontidae); Gambusia holbrooki and Poecilia latipinna (Poeciliidae); Mugil cephalus (Mugilidae); and Dormitator maculatus (Eleotridae). Spawning or birth locations, patterns of growth and development, times of use of the salt marsh as a nursery area, and development of salinity tolerances/osmotic regulatory capabilities were evaluated for each, considering these in the context of variability of environmental conditions, especially of salinity. Five different patterns of reproduction are shown by these 11 species, and only A. xenica appears to be limited to reproducing in the salt marsh environment. Some of these species are capable of reproducing throughout the year. Several of the species are annuals, most others live only 2 or 3 years. Eight species (those other than M. cephalus, A. xenica and G. holbrooki) were found to show no size relationship, large juvenile to adult sizes, in osmotic regulatory capabilities.     

The opioid systems - Panacea and nemesis

This mini-review outlines the opioid systems and their roles primarily as related to reward and compulsive drug/alcohol intake. The central role is taken by the mu-opioid receptor, target for opiate analgesics and also a central target in compulsive alcohol abuse, alcoholism. The mu-opioid receptor and the cognate opioid neuropeptides from proenkephalin and proopiomelancortin are members of a superfamily of opioid systems, each with unique and still to be defined roles in the central nervous system.     

Grazers and soil moisture determine the fate of added 15NH4 + in Yellowstone grasslands

The influence of ungulate grazers on nutrient cycling and ecosystem productivity in grasslands has been shown to differ with moisture, nutrient availability, and feedbacks between above- and belowground activities. We examined the movement of nitrogen (N), applied as (¹⁵NH₄)₂SO₄, through both dry and mesic sites in the northern range of Yellowstone National Park to test the hypothesis that plants were more able to acquire added N in grazed relative to ungrazed sites. Previous studies showed enhanced N mineralization in grazed areas, and detritus removal by grazers was predicted to enhance early-season plant growth. Thirteen months after tracer addition, there were no differences in plant ¹⁵N as a function of grazing, but historically ungrazed sites retained more ¹⁵N in accumulated litter than at grazed sites. This result demonstrated the importance of detritus in regulating redistribution of incoming N and the role of grazers in this process. Site moisture status influenced ¹⁵N recovery in all pools—soils, microbial biomass, and plants—and greater plant ¹⁵N acquisition occurred in roots at dry relative to mesic sites. Understanding how grazers influence nutrient cycling at the landscape scale requires further investigation of interactions among soil moisture, plant production, litter accumulation, grazing intensity, and belowground processes.