Metallothione in-like protein in lobsters ( )

A metallothionein-like protein (MLP) was isolated from naturally cadmium-contaminated lobster hepatopancreas, gills, and green glands. Between 76–99% of the total cadmium was associated with this protein (molecular weight 9,500 daltons) while the remainder was associated with both high (68,000 daltons) and low (<6,000 daltons) molecular weight proteins. MLP was not present in uncontaminated lobster hepatopancreas and only 1% of the total cadmium was associated with the gel filtration fraction corresponding to the protein.     

Forced dispersal of juvenile guanacos (<Emphasis Type="Italic">Lama guanicoe</Emphasis>): causes,variation, and fates of individuals dispersing at different times

We examined adult-juvenile conflict in the guanaco (Lama guanicoe). During spring, territorial males become increasingly aggressive toward all juveniles born the previous year and begin expelling them from family groups. In an apparent effort to reduce aggression, juveniles display submissive crouches when being observed, approached, or attacked by the territorial male. Therefore, we assessed the influence of juvenile submissive behavior on the timing of dispersal and also examined if dispersal time was related to survival and reproductive performance as adults. We also evaluated hypotheses regarding the evolution of juvenile mammalian dispersal in the context of if and how each may favor the forced dispersal of juvenile guanacos by territorial males. Juveniles generally dispersed in late spring and early summer, and a nearly equal proportion of females (n=46; 48%) and males (n=49; 52%) dispersed. More-submissive animals generally dispersed later than less-submissive animals. Juvenile sex and dispersal time were not related to survival. In contrast, juvenile sex and dispersal time were related to reproductive performance. The probability of reproducing was highest when juveniles dispersed early and decreased with increasing time in family groups prior to dispersal. The largest proportion of juveniles was forced to disperse during a 2-week interval following the peak of the breeding season. Competition for food resources is likely very intense at this juncture and territorial males may force older juveniles to disperse in order to divert food resources to younger neonates. Additionally, juveniles may be forced to disperse after territorial males mate their mothers to prevent lost mating opportunities, because females leave territories when their offspring disperse and possibly prior to mating with males. We conclude that the forced dispersal of juvenile guanacos by territorial males is ultimately driven by competition for food resources on territories. The timing of dispersal, however, may be tempered by the chronology of matings between territorial males and particular adult females, and/or genetic relatedness between territorial males and juveniles.     

Habitat partitioning among four elasmobranch species in nearshore,shallow waters of a subtropical embayment in Western Australia

There is a need to explore, in an integrated and statistical manner, how the number of species, relative abundance, species composition and life-cycle stages of elasmobranchs in nearshore waters vary among habitat types and during the year. Therefore, four sites in a large marine embayment, each representing a different habitat type, were sampled at regular intervals. These sites were: (1) unvegetated, with no vegetation within at least 200 m; (2) unvegetated, immediately adjacent to sparse mangroves; (3) unvegetated, immediately adjacent to dense mangroves; and (4) vegetated, with seagrass (Posidonia australis) throughout and in the vicinity. Gill netting caught 10 shark species (5 families), 5 ray species (4 families) and 12 teleost species (10 families). Carcharhinus cautus, which contributed approximately 60% to the numbers of elasmobranchs caught, completed its life cycle in nearshore, shallow waters. Negaprion acutidens, Carcharhinus brevipinna, Carcharhinus limbatus and Rhizoprionodon acutus used these waters as a nursery area. C. cautus was caught mainly in the unvegetated sites, particularly in those near mangroves. N. acutidens was caught entirely in unvegetated sites, while R. acutus, C. brevipinna and Chiloscyllium punctatum were caught predominantly or exclusively in seagrass. The mean number of species and mean catch rate of elasmobranchs were greatest for the seagrass site and least for the unvegetated site with no vegetation within at least 200 m and were significantly less for the latter site than for the unvegetated site immediately adjacent to dense mangroves (P<0.05). The numbers of species and catch rates of elasmobranchs were significantly greater in summer and autumn than in winter (P<0.05) and, in the case of number of species, also than in spring (P<0.05). We conclude that the spatial and food resources in the nearshore, shallow waters of Shark Bay are partitioned among elasmobranch species, thus reducing the potential for competition among these species for the resources in those waters.Communicated by G.F. Humphrey, Sydney     

A SIMULATION OF RIVER-BASIN RESPONSE TO MESOSCALE METEOROLOGICAL FORCING: THE SUSQUEHANNA RIVER BASIN EXPERIMENT (SRBEX)1

ABSTRACT: A mesoscale meteorological model, a surface hydrology model, and a ground-water hydrology model are linked to simulate the hydrographic response of a large river basin to a single storm. Synoptic climatology is employed to choose a representative hydro-climatic event. The mesoscale meteorological model uses three nested domains to simulate relatively high-resolution precipitation over a sub-basin of the Susquehanna River Basin. The hydrology models simulate surface runoff and ground-water baseflow using both analyzed and simulated precipitation. The hydrologic abstractions are handled using both Curve Number and Green-Ampt routines. To support the linkage of the numerical models, special attention is given to data resampling and reprojection. The mesoscale meteorological model simulation captures the spatial and temporal structure of the storm event, while the hydrology models represent the timing of the event well. The Curve Number method generates a realistic hydrograph with both analyzed and simulated precipitation. In contrast, the hydrographic response generated by the Green-Ampt routine is inferior. Several interrelated factors contribute to these results, including: the nature of the precipitation event chosen for the experiment; the tendency of the mesoscale meteorological model to underpredict low intensity, widespread precipitation in this case; and the influence of the surface soil-texture characteristics on infiltration rates.     

Food sharing by sibling vs nonsibling spiny mice (Acomys cahirinus)

Summary In comparison to paired unfamiliar unrelated age-mates, pairs of familiar littermate (sibling) spiny mice (Acomys cahirinus) were more active in exploring a novel environment containing limited food resources and engaged in a greater degree of cooperative feeding or food sharing. When animals born in successive litters were tested, however, familiar siblings did not differ from unfamiliar nonsiblings on measures of food sharing even though subsequent data indicate that such siblings could recognize one another. Young animals were found to feed for longer periods of time than their older cagemate regardless of whether the latter animal was a familiar sibling or an unfamiliar nonsibling.     

Concentrations of Mn,Fe, Cu,Zn and Cd in the mesopelagic decapod Systellaspis debilis from the East Atlantic Ocean

Specimens of the oceanic decapod Systellaspis debilis were collected from six sites in the East Atlantic Ocean between 1970 and 1984, and were analysed for Mn, Fe, Cu, Zn and Cd. The data confirm that there are small but significant differences in mean metal concentrations from some sites which showed no obvious pattern in relation to geographic location of the samples. As a result, ranges of site means are quoted as baseline levels for each metal (g g^-1 dry wt): 2.3 to 2.9 g Mn g^-1, 31.2 to 77.8 g Fe g^-1, 25.9 to 83.4 g Cu g^-1, 41.9 to 92.9 gZn g^-1, 11.1 to 31.8 g Cd g^-1. The concentration of cadmium in S. debilis from all sites was raised relative to cadmium concentrations reported for coastal decapods, perhaps as a result of dietary enrichment. Metal accumulation may provide useful information for understanding the complex feeding behaviour of many oceanic animals.     

Evaluating sources of indoor air pollution

Evaluation of indoor air pollution problems requires an understanding of the relationship between sources, air movement, and outdoor air exchange. Research is underway to investigate these relationships. A three-phase program is being implemented: 1) Environmental chambers are used to provide source emission factors for specific indoor pollutants; 2) An IAQ (Indoor Air Quality) model has been developed to calculate indoor pollutant concentrations based on chamber emissions data and the air exchange and air movement within the indoor environment; and 3) An IAQ test house is used to conduct experiments to evaluate the model results. Examples are provided to show how this coordinated approach can be used to evaluate specific sources of indoor air pollution. Two sources are examined: 1) para-dichlorobenzene emissions from solid moth repellant; and 2) particle emissions from unvented kerosene heaters. The evaluation process for both sources followed the three-phase approach discussed above. Para-dichlorobenzene emission factors were determined by small chamber testing at EPA's Air and Energy Engineering Research Laboratory. Particle emission factors for the kerosene heaters were developed in large chambers at the J. B. Pierce Foundation Laboratory. Both sources were subsequently evaluated in EPA's IAQ test house. The IAQ model predictions showed good agreement with the test house measurements when appropriate values were provided for source emissions, outside air exchange, in-house air movement, and deposition on "sink" surfaces.     

Nitrate and nitric acid concentrations at two Rocky Mountain baseline monitoring sites

A two-tiered, Teflon/nylon filterpack system was used to characterize spatial and temporal patterns of particulate nitrates and nitric acid vapors at two monitoring sites in the Rocky Mountains. Geometric means for particulate nitrates were 38.9 and 52.8 ng/m(3) for the upper and lower sites, respectively. For nitric acid, geometric means of 70.4 ng/m(3) for the upper site and 295 ng/m(3) for the lower site were observed. The relatively low concentrations found at these two sites are comparable to published values for these materials at other remote sites. Atmospheric concentrations of nitrates and nitric acid were correlated significantly at each site, and the total nitrate concentrations (NO(3)(-) plus HNO(3)) were correlated between sites. Comparisons between the two sites indicate that nitric acid concentrations were statistically greater at the lower elevation site, whereas nitrate concentrations were not significantly different. No general seasonal or annual pattern of nitrate or nitric acid concentrations were evident when comparable sampling periods were examined.     

Using cellular automata for integrated modelling of socio-environmental systems

Cellular automata provide the key to a dynamic modelling and simulation framework that integrates socio-economic with environmental models, and that operates at both micro and macro geographical scales. An application to the problem of forecasting the effect of climate change on a small island state suggests that such modelling techniques could help planners and policy makers design more effective policies — policies better tuned both to specific local needs and to overall socio-economic and environmental constraints.Paper presented at the Workshop on GIS Applications in Coastal Zone Management Of Small Island States, Barbados, April 20–22, 1994. RIKS publication 905000/94100, April 1994.