2,628 research outputs found

    Designing and optimizing a micromanipulator-controlled surgical tool for reproducible nerve crush injuries in mice

    Get PDF
    Poster presented at the 2017 Health Sciences Research Day which was organized and sponsored by the University of Missouri School of Medicine Research Council and held on November 9, 2017.Introduction: Recurrent laryngeal nerve (RLN) injury, even if temporary, is a devastating complication of anterior cervical surgical procedures, resulting in debilitating dysphonia and dysphagia. During surgery, injury can be imparted by stretching, crushing, cauterizing, and/or transecting the laryngeal nerves. The injury can be temporary or permanent, depending on the severity and mechanism of insult. Treatment of the injury is generally palliative in nature and includes feeding tubes, voice and swallowing therapy, and diet modifications. The underlying pathophysiology of RLN is not completely understood. To effectively investigate various treatment strategies in mouse models, we need to improve the current translational animal model by standardizing the widely-used manual nerve crush techniques that apply variable force and may unintentionally add traction injuries. To control for these potential confounds, we are developing a micromanipulator-controlled surgical tool that (1) reliably applies a calibrated crush force injury, and (2) minimizes secondary injuries, such as traction, induced by manual methods

    Clouds, shadows, or twilight? Mayfly nymphs recognise the difference

    Get PDF
    1. We examined the relative changes in light intensity that initiate night-time locomotor activity changes in nymphs of the mayfly, Stenonema modestum (Heptageniidae). Tests were carried out in a laboratory stream to examine the hypothesis that nymphs increase their locomotion in response to the large and sustained reductions in relative light intensity that take place during twilight but not to short-term daytime light fluctuations or a minimum light intensity threshold. Ambient light intensity was reduced over a range of values representative of evening twilight. Light was reduced over the same range of intensities either continuously or in discrete intervals while at the same time nymph activity on unglazed tile substrata was video recorded. 2. Nymphs increased their locomotor activity during darkness in response to large, sustained relative light decreases, but not in response to short-term, interrupted periods of light decrease. Nymphs did not recognise darkness unless an adequate light stimulus, such as large and sustained relative decrease in light intensity, had taken place. 3. We show that nymphs perceive light change over time and respond only after a lengthy period of accumulation of light stimulus. The response is much lengthier than reported for other aquatic organisms and is highly adaptive to heterogeneous stream environments

    Fire and Climate Change in the North American Great Lakes Pine Transition Forest

    Get PDF
    This chapter explores potential changes in fire regimes and biodiversity given projected changes in climate in the Great Lakes Pine Transition Forest (GLPF), a portion of the southern boreal forest. We have studied how forest structure, composition, and biodiversity changed over nearly 500 years by comparing communities on comparable edaphic locations of various ages since stand-replacing disturbance. Our interpretation of probable future changes is based on how these ecosystems have reassembled after wildfire, blowdown, and insect disturbances in the past and projections of climate change in the next 75 years. Rapid climate change is now introducing different conditions from those to which this ecosystem was historically adapted, and therefore, projections of future change are more subjective

    Numerical Simulations of N=(1,1) SYM{1+1} with Large Supersymmetry Breaking

    Get PDF
    We consider the N=(1,1)N=(1,1) SYM theory that is obtained by dimensionally reducing SYM theory in 2+1 dimensions to 1+1 dimensions and discuss soft supersymmetry breaking. We discuss the numerical simulation of this theory using SDLCQ when either the boson or the fermion has a large mass. We compare our result to the pure adjoint fermion theory and pure adjoint boson DLCQ calculations of Klebanov, Demeterfi, and Bhanot and of Kutasov. With a large boson mass we find that it is necessary to add additional operators to the theory to obtain sensible results. When a large fermion mass is added to the theory we find that it is not necessary to add operators to obtain a sensible theory. The theory of the adjoint boson is a theory that has stringy bound states similar to the full SYM theory. We also discuss another theory of adjoint bosons with a spectrum similar to that obtained by Klebanov, Demeterfi, and Bhanot.Comment: 12 pages, 4 figure

    Aquatic biosurvey of the Lovell River on UNH land

    Get PDF
    We assessed the physical, chemical and biological conditions at two sites along the Lovell River on University of New Hampshire (UNH) -owned conservation land. The discharge was 4.4 m3 s-1 at Site 1 and 5.7 m3 s -1 downstream at Site 2. Canopy coverage ranged from 8-25%. Canopy was dominated by Eastern Hemlock (79-84%). Much of the stream was strewn with large boulders and the substrate consisted of rocks of highly variable sizes ( 3-549 cm dia.). Specific conductivity (22.1-23.3 µS), pH (6.4) and temperature (7.9-8.3 °C) varied little between sites. Macro-invertebrate bio-indices indicated either excellent water quality with no apparent organic pollution (3.0/10) or good water quality with possible slight organic pollution (4.4/10)
    • …
    corecore