527 research outputs found

    Mineral Lick Visitation by Mountain Goats, Oreamnos americanus

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    Many species, including Mountain Goats (Oreamnos americanus), are known to visit mineral licks, but the extent and duration of use are poorly understood because most studies consist of observations at licks. I studied the movements to, from, and near mineral licks of 11 mountain goats in Washington wearing Global Positioning System (GPS) collars for a total of 169 goat-months of tracking and evaluated chemical composition of six mineral licks compared with reference soil samples. I recorded 101 mineral lick visits to 13 mineral licks. Each GPS fix was classified as moving toward a mineral lick, in the vicinity of a lick, on an excursion from a lick, moving away from a lick, or not associated with lick use. Depending on annual movement patterns associated with lick use, each Mountain Goat was classified as a Migrant (single lick visit of long duration, n = 3 Mountain Goats), Sojourner (few visits of short duration, n = 2), Commuter (many visits of short duration, n = 5), or Resident (lick within normal range of movements, n = 1). Most mineral lick visits took place 01 June-15 August with peak visitation about 14 June-29 July. Migrants typically stayed in the vicinity of licks about a month (but as long as 51 days) whereas other mountain goats visited licks for 0.1-8 days (median = 1 day). Migrants also tended to take longer and move farther than other Mountain Goats when on movements to and from licks. Most Mountain Goats moved toward mineral licks faster (km/hr) than they moved away from licks. All licks had higher concentrations of sodium than reference samples (1.5-27 times as high), although concentrations of calcium, potassium, and sulphate tended to be higher as well, whereas magnesium was not. Mineral lick visitation has costs (energetics of travel, reduced forage, and predation risk). Depending on the importance of these costs, mountain goats evidently use various strategies for exploiting mineral licks as exemplified by the movement types (migrant, sojourner, commuter, or resident). Notably, most of the Mountain Goats in this study crossed national forest, county and Washington Department of Fish and Wildlife region boundaries to another to visit mineral licks. Thus, coordination among administrative units is needed in management of Mountain Goats and mineral licks they use

    Cephalopods from the stomachs of sperm whales taken off California

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    Cephalopod remains (beaks, bodies, and parts of bodies) were collected from the stomachs of 157 sperm whales (Physeter macrocephalus) taken off central California (lat. 37°-39°N). At least 24 species representing 14 families were identified. Frequencies of occurrence of the six most numerous taxa were Moroteuthis robusta 72.0%, Gonatopsis borealis 66.2%, Histioteuthis dofleini 36.9%, Galiteuthis spp. (including G. phyllura and G. pacifica) 36.3%, Octopoteuthis deletron 35.0%, and Vampyroteuthis infernalis 27.4%. One find of two Mesonychoteuthis hamiltoni beaks strongly suggests transequatorial migration by one large male sperm whale. (PDF file contains 18 pages.

    Sector-Based Water Demand Forecasting: Commercial Greenhouses

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    With rising electricity prices, forecasting water demand has become an essential part of the success of any water utility. Numerous forecasting methods have been suggested, but none have been able to characterize the unique consumer mixes that exist for every utility. This work focuses on a water utility located in Essex County, Ontario, Canada. Examination of the utilities consumer breakdown showed that almost 80% of their capacity was being consumed by commercial greenhouse operations. Current forecasting practices in this region for this sector are almost non-existent, assuming fixed demand for all greenhouse operations. This study presents three papers that focus on evaluation and simplification of forecasting techniques for commercial greenhouse operations. The first paper examines influential factors which drive greenhouse water consumption, with an emphasis on practicality. The second paper evaluates several forecasting model architectures ranging from elementary to complex in order to determine the most suitable method(s). The third paper compares water usage between two crops (tomatoes and bell peppers) in an effort to evaluate a crop to crop forecast technique that relies on one crops watering data in order to produce forecasts for another crop

    Evidence of Songbird Intoxication From Rozol Application at a Black-Tailed Prairie Dog Colony

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    Concerns about avian poisonings from anticoagulant rodenticides have traditionally focused on secondary poisoning of raptors exposed by feeding on contaminated mammalian prey. However, ground foraging songbirds can be directly poisoned from operational applications of the anticoagulant rodenticide RozolH (0.005% chlorophacinone, active ingredient) applied as a grain bait, at black-tailed prairie dog Cynomys ludovicianus colonies. A dead western meadowlark Sturnella neglecta recovered from the study prairie dog colony displayed hemorrhaging in brain and pectoral muscle tissue, and it contained chlorophacinone residue concentrations of 0.59 and 0.49 mg/g (wet weight) in the liver and intestinal contents, respectively. Chlorophacinone residues from two Rozol-colored songbird droppings found at the study colony were 0.09 and 0.46 mg/g (wet weight). The timing of the meadowlark mortality and the occurrence of discolored droppings show that songbird exposure and poisoning can occur weeks after a Rozol application

    Chlorine inactivation of Escherichia coli O157:H7.

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    We analyzed isolates of Escherichia coli O157:H7 (which has recently caused waterborne outbreaks) and wild-type E. coli to determine their sensitivity to chlorination. Both pathogenic and nonpathogenic strains were significantly reduced within 1 minute of exposure to free chlorine. Results indicate that chlorine levels typically maintained in water systems are sufficient to inactivate these organisms

    Chronic hypokalemia due to excessive cola consumption: a case report

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    A 52-year-old man was noted to have severe chronic hypokalemia despite discontinuation of diuretic treatment for hypertension and aggressive oral potassium supplementation. His serum potassium normalized temporarily when he was hospitalized, but hypokalemia recurred after discharge. He complained of generalized weakness and fatigue, and occasional loose stools. Physical examination showed mild generalized muscle weakness. Laboratory testing ruled out renal potassium wasting. A dietary history revealed that he was consuming 4 liters of cola per day, with a calculated fructose load of 396 grams per day. Since fructose absorption in the small bowel is relatively inefficient, this probably led to an osmotic diarrhea and GI potassium wasting. Physicians should ask their patients about soft drink consumption when they encounter unexplained hypokalemia

    PCBs and other toxicants in Mysis relicta

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    This research considers the role of Mysis relicta in the recycling of toxic organics in the Lake Michigan ecosystem. Mysids were collected at a station 20 km offshore of Grand Haven, Michigan in spring, summer, and autumn and then size-sorted. In October 1980 and May 1981, plankton samples were collected in two size categories: >78 µm and >156 µm. Mysid fecal pellets and Pontoporeia hoyi were collected in May 1981 while a fourhorn sculpin ( Myoxocephalus quadicornis ) was collected in October 1980. Concentrated extracts of all samples were analyzed for chlorinated hydrocarbons using electron capture gas chromatography. Toxic organics detected were, in order of concentration: PCB, DDE, dieldrin, γ-chlordane, and HCB. DDT, DDD, and α-chlordane were detected less frequently. PCB concentrations in mysids were similar to those observed in their plankton diet and there was no evidence of increased bioaccumulation with increased mysid age. Dieldrin and DDE generally occurred in higher concentrations in older than in younger mysids. Dieldrin concentrations were lower in the plankton than in mysids. Certain toxicants (PCBs, DDD, dieldrin, and γ-chlordane) occurred in higher concentrations in Pontoporeia hoyi than in mysids. Concentrations in the sculpin generally were intermediate to those in amphipods and mysids. Our study suggests that mysids have a significant role in the recycling of toxic organics and that the characteristic pathways vary with the contaminant.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42919/1/10750_2004_Article_BF00008114.pd

    Examination of the surface microlayer of lake michigan using scanning electron microscopy

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24119/1/0000376.pd

    Determination of partition coefficients and aqueous solubilities by reverse phase chromatography--I : Theory and background

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    Water solubilities and octanol/water partition coefficients are widely used to predict partitioning and bioconcentration phenomena for hydrophobic organic pollutants in aqueous systems. This paper is the first in a two part series describing the application of high performance reverse phase liquid chromatography (HPRPLC) for indirect estimation of these two physicochemical parameters to facilitate environmental fate and transport predictions for organic compounds. In the first part, thermodynamic factors which control partitioning processes, water solubilities, and reverse phase retention behavior are discussed, and models for interlinking these three properties are summarized. The second part presents the results of aqueous solubility and octanol/water partition coefficient predictions for a number of organic contaminants from measurements of their HPRPLC behavior, and compares the modeling capabilities of some of the theoretical partitioning/solubility equations developed in the first paper.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26005/1/0000072.pd
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