2,599 research outputs found
The Role of Axonopathy in Parkinson's Disease
New genetic and environmental studies of Parkinson's disease have revealed early problems in synaptic function and connectivity indicating that axonal impairment may be an important hallmark in this disorder. Since many studies suggest that axonal dysfunction precedes cell body loss, it is critical to target axons with treatments aimed at preserving "connectivity" as well as to develop and verify "biomarkers" with which to assess disease progression and drug efficacy
Marijuana and Youth
This paper contains the first estimates of the price sensitivity of the prevalence of youth marijuana use. Survey data on marijuana use by high school seniors from the Monitoring the Future Project are combined with data on marijuana prices and potency from the Drug Enforcement Administration Office of Intelligence or Intelligence Division. Our estimates of the price elasticity of annual marijuana participation range from 0.06 to 0.47, while those for thirty day participation range from 0.002 to 0.69. These estimates clearly imply that changes in the real, quality adjusted price of marijuana contributed significantly to the trends in youth marijuana use between 1982 and 1998, particularly during the contraction in use from 1982 to 1992. Similarly, changes in youth perceptions of the harms associated with regular marijuana use had a substantial impact on both the contraction in use during the 1982 though 1992 period and the subsequent expansion in use after 1992. These findings underscore the usefulness of considering price in addition to more traditional determinants in any analysis of marijuana consumption decisions made by youths.
Friendly-Contention Ads Using Multiple Endorsers: Assessing Source Effects On Attribute Perceptions And Brand Attitudes
Our study is a preliminary investigation of multiple-source friendly-contention ads in which various endorsers argue about the brand's main benefit(s). The results demonstrate that such an ad convinced viewers that originally seemingly inconsistent attributes and benefits could both be found in the advertised brand. Further, the tested advertising format produced more favorable brand attitudes than did an equivalently informative single-source ad version. The argumentative ad appears entirely appropriate in industries where a company wishes to target heavy product users
The impact of phosphorus inputs from small discharges on designated freshwater sites
Natural England, with a contribution from the Broads Authority, commissioned the Centre for Ecology & Hydrology (CEH) in 2009 to conduct a review of the potential risk posed by small domestic discharges, such as from septic tanks, to freshwater SSSIs. The particular focus of this work was the risk of phosphorus (P) pollution to sites that are vulnerable to hyper-eutrophication
WldS but not Nmnat1 protects dopaminergic neurites from MPP+ neurotoxicity
<p>Abstract</p> <p>Background</p> <p>The <it>Wld<sup>S </sup></it>mouse mutant ("Wallerian degeneration-slow") delays axonal degeneration in a variety of disorders including <it>in vivo </it>models of Parkinson's disease. The mechanisms underlying <it>Wld<sup>S </sup></it>-mediated axonal protection are unclear, although many studies have attributed <it>Wld<sup>S </sup></it>neuroprotection to the NAD<sup>+</sup>-synthesizing Nmnat1 portion of the fusion protein. Here, we used dissociated dopaminergic cultures to test the hypothesis that catalytically active Nmnat1 protects dopaminergic neurons from toxin-mediated axonal injury.</p> <p>Results</p> <p>Using mutant mice and lentiviral transduction of dopaminergic neurons, the present findings demonstrate that <it>Wld<sup>S </sup></it>but not Nmnat1, Nmnat3, or cytoplasmically-targeted Nmnat1 protects dopamine axons from the parkinsonian mimetic N-methyl-4-phenylpyridinium (MPP<sup>+</sup>). Moreover, NAD<sup>+ </sup>synthesis is not required since enzymatically-inactive <it>Wld<sup>S </sup></it>still protects. In addition, NAD<sup>+ </sup>by itself is axonally protective and together with <it>Wld<sup>S </sup></it>is additive in the MPP<sup>+ </sup>model.</p> <p>Conclusions</p> <p>Our data suggest that NAD<sup>+ </sup>and <it>Wld<sup>S </sup></it>act through separate and possibly parallel mechanisms to protect dopamine axons. As MPP<sup>+ </sup>is thought to impair mitochondrial function, these results suggest that <it>Wld<sup>S </sup></it>might be involved in preserving mitochondrial health or maintaining cellular metabolism.</p
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