627 research outputs found

    Ketamine kinetics in unmedicated and diazepam‐premedicated subjects

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109775/1/cptclpt1984235.pd

    Altering an extended phenotype reduces intraspecific male aggression and can maintain diversity in cichlid fish

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    Reduced male aggression towards different phenotypes generating negative frequency-dependent intrasexual selection has been suggested as a mechanism to facilitate the invasion and maintenance of novel phenotypes in a population. To date, the best empirical evidence for the phenomenon has been provided by laboratory studies on cichlid fish with different colour polymorphisms. Here we experimentally tested the hypothesis in a natural population of Lake Malawi cichlid fish, in which males build sand-castles (bowers) to attract females during seasonal leks. We predicted that if bower shape plays an important role in male aggressive interactions, aggression among conspecific males should decrease when their bower shape is altered. Accordingly, we allocated randomly chosen bowers in a Nyassachromis cf. microcephalus lek into three treatments: control, manipulated to a different shape, and simulated manipulation. We then measured male behaviours and bower shape before and after these treatments. We found that once bower shape was altered, males were involved in significantly fewer aggressive interactions with conspecific males than before manipulation. Mating success was not affected. Our results support the idea that an extended phenotype, such as bower shape, can be important in maintaining polymorphic populations. Specifically, reduced male conspecific aggression towards males with different extended phenotypes (here, bower shapes) may cause negative frequency-dependent selection, allowing the invasion and establishment of a new phenotype (bower builder). This could help our understanding of mechanisms of diversification within populations, and in particular, the overall diversification of bower shapes within Lake Malawi cichlids

    Opioid Modulation of Oxytocin Release

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97182/1/0091270010361256.pd

    Plasma phencyclidine pharmacokinetics in dog and monkey using a gas chromatography selected ion monitoring assay

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    Phencyclidine was determined by gas chromatography selected ion monitoring in six dogs and seven monkeys. Aliquots of venous blood were taken over 4 h in the monkey after 1.1 mg kg−1 and over 24 h in the dog after 1.0 mg kg−1 of phencyclidine i.v. Pentadeuterated phencyclidine was used as the internal standard. In the electron impact mode the most abundant fragments in the mass spectrum of phencyclidine were m/e 91 and 200, and 96 and 205 in the [2H5]phencyclidine spectrum. These fragments were used to quantitate the amount of phencyclidine present. In both species, a complex exponential decline of plasma phencyclidine was found in most animals that fit a two compartment open model. In monkey, the mean half‐life (β phase) was 2.36 h and in the dog it was 2.86 h. Compared with the monkey, the dog exhibited considerable emergence delirium. The two species had rather different pharmacokinetics which may be relevant to the observed differences in degree of anesthesia and recovery.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/144632/1/bms1200050203.pd

    Positron emission tomography to quantify brain nicotine abstinence

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110042/1/cptclpt2005379.pd

    Effects of urine acidification on plasma and urine phencyclidine levels in overdosage

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/117118/1/cpt1977224421.pd

    Identification of the Plasticity-Relevant Fucose-α(1−2)-Galactose Proteome from the Mouse Olfactory Bulb

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    Fucose-α(1−2)-galactose [Fucα(1−2)Gal] sugars have been implicated in the molecular mechanisms that underlie neuronal development, learning, and memory. However, an understanding of their precise roles has been hampered by a lack of information regarding Fucα(1−2)Gal glycoproteins. Here, we report the first proteomic studies of this plasticity-relevant epitope. We identify five classes of putative Fucα(1−2)Gal glycoproteins: cell adhesion molecules, ion channels and solute carriers/transporters, ATP-binding proteins, synaptic vesicle-associated proteins, and mitochondrial proteins. In addition, we show that Fucα(1−2)Gal glycoproteins are enriched in the developing mouse olfactory bulb (OB) and exhibit a distinct spatiotemporal expression that is consistent with the presence of a “glycocode” to help direct olfactory sensory neuron (OSN) axonal pathfinding. We find that expression of Fucα(1−2)Gal sugars in the OB is regulated by the α(1−2)fucosyltransferase FUT1. FUT1-deficient mice exhibit developmental defects, including fewer and smaller glomeruli and a thinner olfactory nerve layer, suggesting that fucosylation contributes to OB development. Our findings significantly expand the number of Fucα(1−2)Gal glycoproteins and provide new insights into the molecular mechanisms by which fucosyl sugars contribute to neuronal processes

    Gas chromatographic-mass spectrometric analysis of polybrominated biphenyl constituents of Firemaster FF-1

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23145/1/0000069.pd

    Effects of repeated doses of scopolamine on the electroencephalographic stages of sleep in normal volunteers

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/117155/1/cpt1975186727.pd

    The Plasma Interaction Experiment (PIX) description and test program

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    The plasma interaction experiment (PIX) is a battery powered preprogrammed auxiliary payload on the LANDSAT-C launch. This experiment is part of a larger program to investigate space plasma interactions with spacecraft surfaces and components. The varying plasma densities encountered during available telemetry coverage periods are deemed sufficient to determine first order interactions between the space plasma environment and the biased experimental surfaces. The specific objectives of the PIX flight experiment are to measure the plasma coupling current and the negative voltage breakdown characteristics of a solar array segment and a gold plated steel disk. Measurements will be made over a range of surface voltages up to plus or minus kilovolt. The orbital environment will provide a range of plasma densities. The experimental surfaces will be voltage biased in a preprogrammed step sequence to optimize the data returned for each plasma region and for the available telemetry coverage
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