Sediment chemistry (total carbon TC, total nitrogen TN, total phosphorus TP), microbial respiration (dehydrogenase activity, DHA), and ecoenzyme activity (EEA) were measured in 4 zones of similarity ...in the northern Gulf of Mexico (GOM). DHA and EEA reflected the differences in C and N availability associated with proximity to the discharges of the Mississippi and Atchafalaya Rivers, and EEA represented the interface between microbial demands for, and environmental supplies of, nutrients. DHA was positively correlated with beta -glucosidase (BG, r = 0.30), beta -N-acetyl glucosaminidase + L-leucine amino peptidase (NAG + LAP, 0.65), acid phosphatase (AP, 0.17), and aryl sulfatase (SULF, 0.42). EEAs were positively correlated with each other (0.34-0.76). DHA (0.22-0.33), NAG + LAP (0.46-0.64), and SULF (0.17-0.56) were positively correlated with TC, TN, and TP, while BG (0.58-0.60) and AP (0.50-0.58) were correlated only with TC and TN. Carbon use efficiency (CUE) and organic C decomposition rate (M), both based on ecoenzyme models, were positively correlated with TN and TC (0.43-0.46) and TC, TN, and TP (0.24-0.60), respectively. Modeled respiration (Rm), based on M, TC, and sediment bulk density, was correlated with sediment chemistry (0.17-0.90), and with DHA (0.50). All measured chemistry, DHA, EEA, and modeled decomposition parameters exhibited significant cruise, zone, and sediment depth effects, but few significant interaction effects. Structural equation modeling (SEM) revealed a causal relationship between sediment chemistry, EEA, and DHA, explaining 46% of the variance in DHA. As such, the relative activities of the functional classes of ecoenzymes are both a measure of nutrient availability and ecosystem metabolism that may be used to assess large-scale phenomena, such as regional impacts of anthropogenic disturbances.
The perchlorate anion inhibits thyroid hormone (TH) synthesis via inhibition of the sodium‐iodide symporter. It is, therefore, a good model chemical to aid in the development of a bioassay to screen ...chemicals for affects on thyroid function. Xenopus laevis larvae were exposed to sodium perchlorate during metamorphosis, a period of TH‐dependent development, in two experiments. In the first experiment, stage 51 and 54 larvae were exposed for 14 d to 16, 63, 250, 1,000, and 4,000 μg perchlorate/L. In the second experiment, stage 51 larvae were exposed throughout metamorphosis to 8, 16, 32, 63, and 125 μg perchlorate/L. Metamorphic development and thyroid histology were the primary endpoints examined. Metamorphosis was retarded significantly in the first study at concentrations of 250 μg/L and higher, but histological effects were observed at 16 μg/L. In the second study, metamorphosis was delayed by 125 μg/L and thyroid size was increased significantly at 63 μg/L. These studies demonstrate that inhibition of metamorphosis readily can be detected using an abbreviated protocol. However, thyroid gland effects occur at concentrations below those required to elicit developmental delay, demonstrating the sensitivity of this endpoint and suggesting that thyroidal compensation is sufficient to promote normal development until perchlorate reaches critical concentrations.
LeRoy Anderson in 1981 first published, under the titleFor Christ Will Come Tomorrow,his definitive study of a charismatic, millenarian prophet and the Church of Jesus Christ of the Most High. He ...told there of a Mormon posse's 1862 attack on the Morrisite compound, killing Joseph Morris, and of the continuing Morrisite movement, which survived into the mid-twentieth century. In this newly revised edition, Anderson revisits his subject by referring to more recently discovered documents, considering other scholars' continuing work on Morris's sect and related subjects, and examining a 1980s messianic sect that claimed a direct connection to the Morrisites.
New documentary sources include a holograph "History of George Morris," written by Joseph Morris's brother, which Anderson quotes at length. What was once a little-studied subject has since received attention from a number of scholars. Anderson references such current work on Mormon schismatic movements and broader subjects, much of which drew on his work. Perhaps the book's most interesting and unintended influence was on that obscure 1980s messianic sect, in Montana, which learned of Morris throughJoseph Morris and the Saga of the Morrisites.
SUMMARY
1. In this study we predict stream sensitivity to non‐point source pollution based on the non‐linear responses of hydrological regimes and associated loadings of non‐point source pollutants ...to catchment properties. We assessed two hydrologically based thresholds of impairment, one for catchment storage (5–10%) and one for mature forest (<50% versus >60% of catchment in mature forest cover) across two different hydrogeomorphic regions within the Northern Lakes and Forest (NLF) ecoregion: the North Shore predominantly within the North Shore Highlands Ecological Unit and the South Shore (predominantly within the Lake Superior Clay Plain Ecological Unit). Water quality samples were collected and analysed during peak snowmelt and baseflow conditions from 24 second‐order streams grouped as follows: three in each region × catchment storage × mature forest class.
2. Water quality was affected by a combination of regional influences, catchment storage and mature forest. Regional differences were significant for suspended solids, phosphorus, nitrogen: phosphorus ratios, dissolved organic carbon (DOC) and alkalinity. Catchment storage was significantly correlated with dissolved silica during the early to mid‐growing season, and with DOC, specific conductance and alkalinity during all seasons. Total nitrogen and dissolved nitrogen were consistently less in low mature forest than in high mature forest catchments. Catchment storage interacted with the influence of mature forest for only two metrics: colour and the soluble inorganic nitrogen : phosphorus ratio.
3. Significant interaction terms (region by mature forest or region by storage) suggest differences in regional sensitivity for conductance, alkalinity, total organic carbon, and colour, as well as possible shifts in thresholds of impact across region or mature forest class.
4. Use of the NLF Ecoregion alone as a basis for setting regional water quality criteria would lead to the misinterpretation of reference condition and assessment of condition. There were pronounced differences in background water quality between the North and South Shore streams, particularly for parameters related to differences in soil parent material and glacial history. A stratified random sampling design for baseflow and snowmelt stream water quality based on both hydrogeomorphic region and catchment attributes improves assessments of both reference condition and differences in regional sensitivity.
Using data on second- and third-order watersheds overlapping with the North Shore and the South Shore of the western arm of Lake Superior, the effects of region, landscape, and scale effects on water ...quality in Lake Superior tributaries were explored. The second-order streams were sampled monthly during mid-summer to late summer 1997 and during peak snowmelt until mid-summer in 1998, and third-order streams were sampled three times during mid-summer to fall 1998 and four times in 1999 between peak snowmelt through fall. Water-quality parameters were analyzed using repeated measures analysis of covariance. Watershed-scale attributes were found to explain a significant amount of variation in background water quality and sensitivity to nonpoint source pollution, as well as in baseflow water quality. The observed regional differences varied over time for constituents that were sensitive to biological activity, while effects of watershed storage varied seasonally for constituents that were affected by hydrology and redox conditions. Deforestation effects were more evident for third-order streams compared to second-order streams, as were the effects of watershed storage.
In 1998 and 1999, third‐order watersheds in high mature forest (HMF) and low mature forest (LMF) classes were selected along gradients of watershed storage within each of two hydrogeomorphic regions ...in the Lake Superior Basin to evaluate threshold effects of storage on hydrologic regimes and watershed exports. Differences were detected between regions (North and South Shore) for particulates, nutrients, and pH, with all but silica values higher for South Shore streams (p < 0.05). Mature forest effects were detected for turbidity, nutrients, color, and alkalinity, with higher values in the LMF watersheds, that is, watersheds with less that 50 percent mature forest cover. Dissolved N, ammonium, N:P, organic carbon, and color increased, while suspended solids, turbidity, and dissolved P decreased as a function of storage. Few two‐way interactions were detected between region and mature forest or watershed storage, thus threshold based classification schemes could be used to extrapolate effects across regions. Both regional differences in water quality and those associated with watershed attributes were more common for third‐order streams in the western Lake Superior drainage basin as compared with second‐order streams examined in an earlier study. Use of ecoregions alone as a basis for setting regional water quality criteria would have led to misinterpretation of reference condition and assessment of impacts in the Northern Lakes and Forest Ecoregion.
The organophosphorus insecticide azinphos-methyl was applied once to the surface of 12 of 18 littoral enclosure mesocosms (5×10 m) constructed in a 2-ha pond near Duluth, Minnesota. Water, sediment, ...macrophytes, and adult fathead minnows were analyzed for residue to determine the persistence, distribution, and mass balance of azinphos-methyl. Nominal treatment concentrations were 0, 0.2, 1, 4, and 20 μg/liter active ingredient. The maximum residue concentration in the water was measured 1h after treatment. The half-life in the water column ranged from 1.2 to 2 days and 95% of the residue dissipated in 5.4 to 10.2 days. Measurable residues were found in the sediment, macrophytes, and fish. Maximum residues in these media were measured at 4, 1, and 0.12 days. respectively. The water and sediment were the most important sorptive compartments for azinphos-methyl residue. The macrophytes and fish were of minor importance, containing only trace amounts of the mass applied.