597 research outputs found

    A problem solving approach to instructional evaluation

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    When one looks at a person before he is able to solve a problem and then after he has solved the problem, one observes that change has occurred

    Quantification of Phenotypic Change Resulting in Sensitization of Primary Sensory Neurons due to Oxidative Stress

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    84% of the population will suffer from low back pain at some point in their lives, and 39% of the cases may be related to pain originating from the intervertebral disc (IVD) also known as discogenic pain. Age or injury can cause progressive degeneration of the IVD, and this can allow innervation by nociceptive (pain-sensing) neurons from the dorsal root ganglion (DRG) into the inner IVD.6 Long-term exposure to pain-inducing stimuli can cause nociceptor sensitization, manifested as increased pain sensation in response to non-painful or painful stimuli.7 Sensitization results in the nociceptors responding more strongly to a stimulus, and the activation energy required for response is reduced.8 During IVD degeneration, inflammation and oxidative stress create excess reactive oxygen species (ROS) .9 ROS such as superoxide may play a role in nociceptive signaling and lead to nociceptor sensitization.8 ROS are involved in the chronic pain that results from nerve injury or inflammation in many contexts and may be involved in discogenic pain as well.10 The focus of this study is to determine if long-term oxidative stress causes a change in the DRG nociceptive neuron phenotype related to sensitization. This would increase the expression of pain-related ion channels and lower the neuronal activation threshold. 1. DePalma et al. (2011) 2. Balague et al. (2012) 3. Zhang et al. (2010) 4. Humzah et al. (1988) 5. Ohtori et al. (2015) 6. Yang et al. (2018) 7. Woolf et al. (2010) 8. Chung et al. (2004) 9. Nasto et al. (2013) 10. Yowtak et al. (2011

    Engineering a multicompartment in vitro model for dorsal root ganglia phenotypic assessment

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    Despite the significant global prevalence of chronic pain, current methods to identify pain therapeutics often fail translation to the clinic. Phenotypic screening platforms rely on modeling and assessing key pathologies relevant to chronic pain, improving predictive capability. Patients with chronic pain often present with sensitization of primary sensory neurons (that extend from dorsal root ganglia [DRG]). During neuronal sensitization, painful nociceptors display lowered stimulation thresholds. To model neuronal excitability, it is necessary to maintain three key anatomical features of DRGs to have a physiologically relevant platform: (1) isolation between DRG cell bodies and neurons, (2) 3D platform to preserve cell–cell and cell-matrix interactions, and (3) presence of native non-neuronal support cells, including Schwann cells and satellite glial cells. Currently, no culture platforms maintain the three anatomical features of DRGs. Herein, we demonstrate an engineered 3D multicompartment device that isolates DRG cell bodies and neurites and maintains native support cells. We observed neurite growth into isolated compartments from the DRG using two formulations of collagen, hyaluronic acid, and laminin-based hydrogels. Further, we characterized the rheological, gelation and diffusivity properties of the two hydrogel formulations and found the mechanical properties mimic native neuronal tissue. Importantly, we successfully limited fluidic diffusion between the DRG and neurite compartment for up to 72 h, suggesting physiological relevance. Lastly, we developed a platform with the capability of phenotypic assessment of neuronal excitability using calcium imaging. Ultimately, our culture platform can screen neuronal excitability, providing a more translational and predictive system to identify novel pain therapeutics to treat chronic pain

    Characterizing Viewpoints of Scholars in Agricultural Communications as they Relate to Research Themes in the Journal of Applied Communications: A Q Methodological Study

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    Research in agricultural communications is not guided by a national research agenda. Therefore, the substantial body of research produced from scholars working in the discipline represents scattered efforts. We conducted a content analysis of journal articles published in the Journal of Applied Communications between 2000 and 2019 to identify the research themes that establish the discipline’s scholarly base. Through an examination of n = 259 journal articles, we identified N = 27 research themes, the most prevalent of which included agriculture and media relations/practices (f = 30; % = 11.58), public perceptions/understanding of agriculture and natural resources (f = 25; % = 9.65), and agricultural communications academic programs and curricula (f = 21; % = 8.11). Then, we used Q methodology to identify viewpoints of agricultural communications scholars (e.g., faculty, graduate students; n = 45) as they relate to perceptions about the importance of research. We identified four dominant viewpoints of scholars in agricultural communications: Message Framing Influencers, Extension-Focused Scholars and Practitioners, Discipline-Conscious Researchers, and Tech-Savvy Scholars. Together, these viewpoints explained 59.43% of the study variance. Although participants who represented each of these groups had unique perspectives, participants generally agreed that public perceptions/understanding of agriculture and natural resources and crisis communications in agricultural communications were important research themes. Likewise, they generally agreed that the role of agricultural communications professional organizations, agricultural communications efforts during historical events, and agritourism were not important research themes

    Hook3 is a scaffold for the opposite-polarity microtubule-based motors cytoplasmic dynein-1 and KIF1C.

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    The unidirectional and opposite-polarity microtubule-based motors, dynein and kinesin, drive long-distance intracellular cargo transport. Cellular observations suggest that opposite-polarity motors may be coupled. We recently identified an interaction between the cytoplasmic dynein-1 activating adaptor Hook3 and the kinesin-3 KIF1C. Here, using in vitro reconstitutions with purified components, we show that KIF1C and dynein/dynactin can exist in a complex scaffolded by Hook3. Full-length Hook3 binds to and activates dynein/dynactin motility. Hook3 also binds to a short region in the "tail" of KIF1C, but unlike dynein/dynactin, this interaction does not activate KIF1C. Hook3 scaffolding allows dynein to transport KIF1C toward the microtubule minus end, and KIF1C to transport dynein toward the microtubule plus end. In cells, KIF1C can recruit Hook3 to the cell periphery, although the cellular role of the complex containing both motors remains unknown. We propose that Hook3's ability to scaffold dynein/dynactin and KIF1C may regulate bidirectional motility, promote motor recycling, or sequester the pool of available dynein/dynactin activating adaptors

    The Charge Form Factor of the Neutron at Low Momentum Transfer from the 2H⃗(e⃗,e′n)p^{2}\vec{\rm H}(\vec{\rm e},{\rm e}'{\rm n}){\rm p} Reaction

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    We report new measurements of the neutron charge form factor at low momentum transfer using quasielastic electrodisintegration of the deuteron. Longitudinally polarized electrons at an energy of 850 MeV were scattered from an isotopically pure, highly polarized deuterium gas target. The scattered electrons and coincident neutrons were measured by the Bates Large Acceptance Spectrometer Toroid (BLAST) detector. The neutron form factor ratio GEn/GMnG^{n}_{E}/G^{n}_{M} was extracted from the beam-target vector asymmetry AedVA_{ed}^{V} at four-momentum transfers Q2=0.14Q^{2}=0.14, 0.20, 0.29 and 0.42 (GeV/c)2^{2}.Comment: 5 pages, 3 figures, submitted to Phys. Rev. Let

    Ectopic endometrium in human foetuses is a common event and sustains the theory of müllerianosis in the pathogenesis of endometriosis, a disease that predisposes to cancer

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    <p>Abstract</p> <p>Background</p> <p>Endometriosis is a gynecological disease defined by the histological presence of endometrial glands and stroma outside the uterine cavity. Women with endometriosis have an increased risk of different types of malignancies, especially ovarian cancer and non-Hodgkin's lymphoma. Though there are several theories, researchers remain unsure as to the definitive cause of endometriosis. Our objective was to test the validity of the theory of müllerianosis for endometriosis, that is the misplacing of primitive endometrial tissue along the migratory pathway of foetal organogenesis</p> <p>Methods</p> <p>We have collected at autopsy 36 human female foetuses at different gestational age. We have performed a morphological and immunohistochemical study (expression of oestrogen receptor and CA125) on the pelvic organs of the 36 foetuses included en-block and totally analyzed.</p> <p>Results</p> <p>In 4 out of 36 foetuses we found presence of misplaced endometrium in five different ectopic sites: in the recto-vaginal septum, in the proximity of the Douglas pouch, in the mesenchimal tissue close to the posterior wall of the uterus, in the rectal tube at the level of muscularis propria, and in the wall of the uterus. All these sites are common location of endometriosis in women.</p> <p>Conclusion</p> <p>We propose that a cause of endometriosis is the dislocation of primitive endometrial tissue outside the uterine cavity during organogenesis.</p

    Measurement of the proton electric to magnetic form factor ratio from \vec ^1H(\vec e, e'p)

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    We report the first precision measurement of the proton electric to magnetic form factor ratio from spin-dependent elastic scattering of longitudinally polarized electrons from a polarized hydrogen internal gas target. The measurement was performed at the MIT-Bates South Hall Ring over a range of four-momentum transfer squared Q2Q^2 from 0.15 to 0.65 (GeV/c)2^2. Significantly improved results on the proton electric and magnetic form factors are obtained in combination with previous cross-section data on elastic electron-proton scattering in the same Q2Q^2 region.Comment: 4 pages, 2 figures, submitted to PR
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