62 research outputs found

    Ecology of the Black-Footed Ferret and the Black-Tailed Prairie Dog

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    Research involving the black-footed ferret (Mustela nigripes) and black-tailed prairie dog (Cynomys ludovicianus) was conducted during 1968 and 1969. Eighteen prairie dog burrows were excavated in 1968 and 1969. Burrow systems ranged from 13 to 109 feet long and 3 to 14 feet deep. Fifteen of the burrows exhibited dome-shaped entrances leading to a gradually descending passageway which made an abrupt vertical ascent to a crater-shaped entrance. Nest chambers were found in 6 burrows. Earthen plugs created by prairie dogs in burrows after ferret departure ranged from 9 to 33 feet long. Eighty-two ferret scats were recovered. Animal remains found in ferret scats were mouse (86 percent) and prairie dog (14 percent). Mouse remains occurred in 32 percent of scats in 1968 on a town which had four young ferrets and 9 percent in 1969 with one young ferret on the town. Rabbit hair was recovered from the intestine of one roadkilled ferret. Although prairie dog activity appeared to peak at 8:00 a.m. and 8:00 p.m. during the last two weeks of July, least variation among counts occurred in midafternoon. Counts throughout the summer of 1969 indicated optimum censusing conditions existed on a still, overcast afternoon within a temperature range of 74 to 76°F. Five to 41 counts were required to detect changes of 10 percent in population weith a probability of 0.95 under these optimum conditions. The number of prairie dogs on a town with five ferrets in 1968 and two in 1969 decreased 16 percent from 1968 to 1969 while counts on three other town increased 19, 42, and 28 percent. One ferret was reported seen one morning in 1968 on the town the increased 28 percent. The town decreasing in prairie dog population differed significantly (P\u3c0.01) in population change from the others. Prairie dogs were observed creating curved trough-like formations on their mounds that could be confused with earthen trenches created by ferrets. Unlike the prairie dog troughs, ferret trenches were usually straight and often extended off the burrow mound. Two ferrets were captured with snares and three were live trapped for ear marking by notches and tags; live trapping proved more convenient. Both markings were readily observable at a distance of 30 yards with aid of 7x50 binoculars

    Current Status of the Woodcock in Iowa

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    Iowa is at the western edge of the continental range of woodcock. Because of their scarcity in the state, little interest has been shown in them. They are a prized game bird in many states in the eastern half of the country. In 1961, Iowa began participating in the annual U.S. Fish and Wildlife Service spring woodcock census, which has increased efforts to learn more about this species in the state. The spring singing-ground census of courting males revealed that a low population of breeding woodcock exists in suitable habitat, primarily limited to the eastern one-third of the state. Thirty verified records of nesting woodcock in Iowa, most from brood sightings, were recorded during the 1960\u27s and 1970\u27s. These bracketed the state from the Mississippi to the Missouri rivers. Other sightings have been reported from various locations in the state during spring and fall migration. A composite of information available showed that woodcock are not abundant but are widely distributed over Iowa

    In Vivo Evaluation of Quantitative Percussion Diagnostics for Determining Implant Stability

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    PURPOSE: A percussion instrument (Periometer(®), Perimetrics LLC, Newport Beach, CA, USA) and rat model were used to test the hypothesis: percussion diagnostics provides reliable, reproducible indications of osseointegration. MATERIALS AND METHODS: Titanium implants were placed in femurs of 36 Sprague-Dawley rats. Each animal was assigned to one of six groups of six defined by one of three time points (2, 4, or 8 weeks post-placement) and one of two treatments (MMP inhibitor or vehicle). Percussion testing was conducted three times/subject at implant placement and at one of the time points. For each time point, there was an experimental group that received daily intraperitoneal injections of GM6001, and a control group that received no MMP inhibitor. The percussion data consisted of loss coefficient (LC) values that characterize energy dissipation. Statistical analysis was performed on the LC values for two animal groups using the paired Student t test to assess differences as a function of time, and the independent t test to compare mean LC for the study groups at sacrifice (α=0.05). Histological evaluation using the osteogenic CD40 protein marker was also performed. RESULTS: A nearly significant difference in mean LC at the 2-week time point was observed between the two treatments with the GM6001 group having the higher value (p = 0.053). There was a greater difference between the mean LC values for the 4-week GM6001 and vehicle groups (p = 0.001). The histological evidence for subjects in these two groups confirmed reduction of osteogenesis at the implant interface after administration of the MMP inhibitor. CONCLUSIONS: Lower vehicle LC values relative to the GM6001 therapeutic group were observed, consistent with the effect MMP inhibition has on matrix remodeling at the implant bone interface. This finding in conjunction with histological observations confirms that osseointegration can be monitored using percussion diagnostics

    Fast- or Slow-inactivated State Preference of Na+ Channel Inhibitors: A Simulation and Experimental Study

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    Sodium channels are one of the most intensively studied drug targets. Sodium channel inhibitors (e.g., local anesthetics, anticonvulsants, antiarrhythmics and analgesics) exert their effect by stabilizing an inactivated conformation of the channels. Besides the fast-inactivated conformation, sodium channels have several distinct slow-inactivated conformational states. Stabilization of a slow-inactivated state has been proposed to be advantageous for certain therapeutic applications. Special voltage protocols are used to evoke slow inactivation of sodium channels. It is assumed that efficacy of a drug in these protocols indicates slow-inactivated state preference. We tested this assumption in simulations using four prototypical drug inhibitory mechanisms (fast or slow-inactivated state preference, with either fast or slow binding kinetics) and a kinetic model for sodium channels. Unexpectedly, we found that efficacy in these protocols (e.g., a shift of the “steady-state slow inactivation curve”), was not a reliable indicator of slow-inactivated state preference. Slowly associating fast-inactivated state-preferring drugs were indistinguishable from slow-inactivated state-preferring drugs. On the other hand, fast- and slow-inactivated state-preferring drugs tended to preferentially affect onset and recovery, respectively. The robustness of these observations was verified: i) by performing a Monte Carlo study on the effects of randomly modifying model parameters, ii) by testing the same drugs in a fundamentally different model and iii) by an analysis of the effect of systematically changing drug-specific parameters. In patch clamp electrophysiology experiments we tested five sodium channel inhibitor drugs on native sodium channels of cultured hippocampal neurons. For lidocaine, phenytoin and carbamazepine our data indicate a preference for the fast-inactivated state, while the results for fluoxetine and desipramine are inconclusive. We suggest that conclusions based on voltage protocols that are used to detect slow-inactivated state preference are unreliable and should be re-evaluated

    Developmental Neurotoxicity Study of Dietary Bisphenol A in Sprague-Dawley Rats

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    This study was conducted to determine the potential of bisphenol A (BPA) to induce functional and/or morphological effects to the nervous system of F1 offspring from dietary exposure during gestation and lactation according to the Organization for Economic Cooperation and Development and U.S. Environmental Protection Agency guidelines for the study of developmental neurotoxicity. BPA was offered to female Sprague-Dawley Crl:CD (SD) rats (24 per dose group) and their litters at dietary concentrations of 0 (control), 0.15, 1.5, 75, 750, and 2250 ppm daily from gestation day 0 through lactation day 21. F1 offspring were evaluated using the following tests: detailed clinical observations (postnatal days [PNDs] 4, 11, 21, 35, 45, and 60), auditory startle (PNDs 20 and 60), motor activity (PNDs 13, 17, 21, and 61), learning and memory using the Biel water maze (PNDs 22 and 62), and brain and nervous system neuropathology and brain morphometry (PNDs 21 and 72). For F1 offspring, there were no treatment-related neurobehavioral effects, nor was there evidence of neuropathology or effects on brain morphometry. Based on maternal and offspring body weight reductions, the no-observed-adverse-effect level (NOAEL) for systemic toxicity was 75 ppm (5.85 and 13.1 mg/kg/day during gestation and lactation, respectively), with no treatment-related effects at lower doses or nonmonotonic dose responses observed for any parameter. There was no evidence that BPA is a developmental neurotoxicant in rats, and the NOAEL for developmental neurotoxicity was 2250 ppm, the highest dose tested (164 and 410 mg/kg/day during gestation and lactation, respectively)

    A communal catalogue reveals Earth’s multiscale microbial diversity

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    Our growing awareness of the microbial world’s importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth’s microbial diversity

    A communal catalogue reveals Earth's multiscale microbial diversity

    Get PDF
    Our growing awareness of the microbial world's importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth's microbial diversity.Peer reviewe

    Competing on Innovation: Implications for Building the Middle-Skill Talent Pipeline

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    This 33-page paper, written by Robert G. Sheets and Jason A. Tyszko, discusses increased innovation competition for United States businesses and workers. This paper addresses the growing importance of innovation in global competitiveness, defines innovation and explores major types, provides an overview of research on the changing organization of work, explores promising practices, and then concludes with a call for further research. This paper includes the following sections: Competing on Innovation and the Race against Routine Work, What Do We Mean By Innovation, Multiple Types of Innovation, The Discipline of Innovation Embedded in All Work, The Changing Organization of Work and the Role of Open Cross-Functional Teams, Open Cross-Functional Teams: The Horizontal Dimension of Work, Building Innovation Capacity and Talent in Organizations, Promising Practices for Building Talent Pipelines, Illinois Innovation Talent, Career Pathway Frameworks and Sector Initiatives, and more.Â
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