116 research outputs found

    Engaging Hard-to-Reach Audiences through Internal Interdisciplinary and External Diverse Collaborations

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    Through a combination of internal and external collaborations, consumer-based energy education designed for hard-to-reach audiences was successfully delivered statewide by an interdisciplinary Extension team. Program participants representing rural residents, senior citizens, and low-income audiences demonstrated improvements in knowledge and increased intention to change their home electricity usage behaviors. This outreach work can serve as a model for other Extension services to combine interdisciplinary teams with community partnerships to reach underserved audiences statewide

    A Nutrient-Regulated Cyclic Diguanylate Phosphodiesterase Controls Clostridium difficile Biofilm and Toxin Production during Stationary Phase

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    ABSTRACT The signaling molecule cyclic diguanylate (c-di-GMP) mediates physiological adaptation to extracellular stimuli in a wide range of bacteria. The complex metabolic pathways governing c-di-GMP synthesis and degradation are highly regulated, but the specific cues that impact c-di-GMP signaling are largely unknown. In the intestinal pathogen Clostridium difficile , c-di-GMP inhibits flagellar motility and toxin production and promotes pilus-dependent biofilm formation, but no specific biological functions have been ascribed to any of the individual c-di-GMP synthases or phosphodiesterases (PDEs). Here, we report the functional and biochemical characterization of a c-di-GMP PDE, PdcA, 1 of 37 confirmed or putative c-di-GMP metabolism proteins in C. difficile 630. Our studies reveal that pdcA transcription is controlled by the nutrient-regulated transcriptional regulator CodY and accordingly increases during stationary phase. In addition, PdcA PDE activity is allosterically regulated by GTP, further linking c-di-GMP levels to nutrient availability. Mutation of pdcA increased biofilm formation and reduced toxin biosynthesis without affecting swimming motility or global intracellular c-di-GMP. Analysis of the transcriptional response to pdcA mutation indicates that PdcA-dependent phenotypes manifest during stationary phase, consistent with regulation by CodY. These results demonstrate that inactivation of this single PDE gene is sufficient to impact multiple c-di-GMP-dependent phenotypes, including the production of major virulence factors, and suggest a link between c-di-GMP signaling and nutrient availability

    A Nutrient-Regulated Cyclic Diguanylate Phosphodiesterase Controls Clostridium difficile Biofilm and Toxin Production During Stationary Phase

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    The signaling molecule cyclic diguanylate (c-di-GMP) mediates physiological adaptation to extracellular stimuli in a wide range of bacteria. The complex metabolic pathways governing c-di-GMP synthesis and degradation are highly regulated, but the specific cues that impact c-di-GMP signaling are largely unknown. In the intestinal pathogen Clostridium difficile, c-di-GMP inhibits flagellar motility and toxin production and promotes pilus-dependent biofilm formation, but no specific biological functions have been ascribed to any of the individual c-di-GMP synthases or phosphodiesterases (PDEs). Here, we report the functional and biochemical characterization of a c-di-GMP PDE, PdcA, 1 of 37 confirmed or putative c-di-GMP metabolism proteins in C. difficile 630. Our studies reveal that pdcA transcription is controlled by the nutrient-regulated transcriptional regulator CodY and accordingly increases during stationary phase. In addition, PdcA PDE activity is allosterically regulated by GTP, further linking c-di-GMP levels to nutrient availability. Mutation of pdcA increased biofilm formation and reduced toxin biosynthesis without affecting swimming motility or global intracellular c-di-GMP. Analysis of the transcriptional response to pdcA mutation indicates that PdcA-dependent phenotypes manifest during stationary phase, consistent with regulation by CodY. These results demonstrate that inactivation of this single PDE gene is sufficient to impact multiple c-di-GMP-dependent phenotypes, including the production of major virulence factors, and suggest a link between c-di-GMP signaling and nutrient availability

    Limbic-Predominant Age-Related TDP-43 Encephalopathy Differs from Frontotemporal Lobar Degeneration

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    TAR-DNA binding protein-43 (TDP-43) proteinopathy is seen in multiple brain diseases. A standardized terminology was recommended recently for common age-related TDP-43 proteinopathy: limbic-predominant, age-related TDP-43 encephalopathy (LATE) and the underlying neuropathological changes, LATE-NC. LATE-NC may be co-morbid with Alzheimer’s disease neuropathological changes (ADNC). However, there currently are ill-defined diagnostic classification issues among LATE-NC, ADNC, and frontotemporal lobar degeneration with TDP-43 (FTLD-TDP). A practical challenge is that different autopsy cohorts are composed of disparate groups of research volunteers: hospital- and clinic-based cohorts are enriched for FTLD-TDP cases, whereas community-based cohorts have more LATE-NC cases. Neuropathological methods also differ across laboratories. Here, we combined both cases and neuropathologists’ diagnoses from two research centres—University of Pennsylvania and University of Kentucky. The study was designed to compare neuropathological findings between FTLD-TDP and pathologically severe LATE-NC. First, cases were selected from the University of Pennsylvania with pathological diagnoses of either FTLD-TDP (n = 33) or severe LATE-NC (mostly stage 3) with co-morbid ADNC (n = 30). Sections from these University of Pennsylvania cases were cut from amygdala, anterior cingulate, superior/mid-temporal, and middle frontal gyrus. These sections were stained for phospho-TDP-43 immunohistochemically and evaluated independently by two University of Kentucky neuropathologists blinded to case data. A simple set of criteria hypothesized to differentiate FTLD-TDP from LATE-NC was generated based on density of TDP-43 immunoreactive neuronal cytoplasmic inclusions in the neocortical regions. Criteria-based sensitivity and specificity of differentiating severe LATE-NC from FTLD-TDP cases with blind evaluation was ∼90%. Another proposed neuropathological feature related to TDP-43 proteinopathy in aged individuals is ‘Alpha’ versus ‘Beta’ in amygdala. Alpha and Beta status was diagnosed by neuropathologists from both universities (n = 5 raters). There was poor inter-rater reliability of Alpha/Beta classification (mean κ = 0.31). We next tested a separate cohort of cases from University of Kentucky with either FTLD-TDP (n = 8) or with relatively ‘pure’ severe LATE-NC (lacking intermediate or severe ADNC; n = 14). The simple criteria were applied by neuropathologists blinded to the prior diagnoses at University of Pennsylvania. Again, the criteria for differentiating LATE-NC from FTLD-TDP was effective, with sensitivity and specificity ∼90%. If more representative cases from each cohort (including less severe TDP-43 proteinopathy) had been included, the overall accuracy for identifying LATE-NC was estimated at \u3e 98% for both cohorts. Also across both cohorts, cases with FTLD-TDP died younger than those with LATE-NC (P \u3c 0.0001). We conclude that in most cases, severe LATE-NC and FTLD-TDP can be differentiated by applying simple neuropathological criteria

    Observations and Theoretical Implications of the Large Separation Lensed Quasar SDSS J1004+4112

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    We study the recently discovered gravitational lens SDSS J1004+4112, the first quasar lensed by a cluster of galaxies. It consists of four images with a maximum separation of 14.62''. The system has been confirmed as a lensed quasar at z=1.734 on the basis of deep imaging and spectroscopic follow-up observations. We present color-magnitude relations for galaxies near the lens plus spectroscopy of three central cluster members, which unambiguously confirm that a cluster at z=0.68 is responsible for the large image separation. We find a wide range of lens models consistent with the data, but they suggest four general conclusions: (1) the brightest cluster galaxy and the center of the cluster potential well appear to be offset by several kpc; (2) the cluster mass distribution must be elongated in the North--South direction, which is consistent with the observed distribution of cluster galaxies; (3) the inference of a large tidal shear (~0.2) suggests significant substructure in the cluster; and (4) enormous uncertainty in the predicted time delays between the images means that measuring the delays would greatly improve constraints on the models. We also compute the probability of such large separation lensing in the SDSS quasar sample, on the basis of the CDM model. The lack of large separation lenses in previous surveys and the discovery of one in SDSS together imply a mass fluctuation normalization \sigma_8=1.0^{+0.4}_{-0.2} (95% CL), if cluster dark matter halos have an inner slope -1.5. Shallower profiles would require higher values of \sigma_8. Although the statistical conclusion might be somewhat dependent on the degree of the complexity of the lens potential, the discovery is consistent with the predictions of the abundance of cluster-scale halos in the CDM scenario. (Abridged)Comment: 21 pages, 24 figures, 5 tables, accepted for publication in Ap

    The difficult doctor? Characteristics of physicians who report frustration with patients: an analysis of survey data

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    BACKGROUND: Literature on difficult doctor-patient relationships has focused on the "difficult patient." Our objective was to determine physician and practice characteristics associated with greater physician-reported frustration with patients. METHODS: We conducted a secondary analysis of the Physicians Worklife Survey, which surveyed a random national sample of physicians. Participants were 1391 family medicine, general internal medicine, and medicine subspecialty physicians. The survey assessed physician and practice characteristics, including stress, depression and anxiety symptoms, practice setting, work hours, case-mix, and control over administrative and clinical practice. Physicians estimated the percentage of their patients who were "generally frustrating to deal with." We categorized physicians by quartile of reported frustrating patients and compared characteristics of physicians in the top quartile to those in the other three quartiles. We used logistic regression to model physician characteristics associated with greater frustration. RESULTS: In unadjusted analyses, physicians who reported high frustration with patients were younger (p < 0.001); worked more hours per week (p = 0.041); and had more symptoms of depression, stress, and anxiety (p < 0.004 for all). In the final model, factors independently associated with high frustration included age < 40 years, work hours > 55 per week, higher stress, practice in a medicine subspeciality, and greater number of patients with psychosocial problems or substance abuse. CONCLUSION: Personal and practice characteristics of physicians who report high frustration with patients differ from those of other physicians. Understanding factors contributing to physician frustration with patients may allow us to improve the quality of patient-physician relationships

    Selection for Forage and Avoidance of Risk by Woodland Caribou (Rangifer Tarandus Caribou) at Coarse andLocal Scales

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    The relationship between selection at coarse and fine spatiotemporal spatial scales is still poorly understood. Some authors claim that, to accommodate different needs at different scales, individuals should have contrasting selection patterns at different scales of selection, while others claim that coarse scale selection patterns should reflect fine scale selection decisions. Here we examine site selection by 110 woodland caribou equipped with GPS radio‐collars with respect to forage availability and predation risk across a broad gradient in availability of both variables in boreal forests of Northern Ontario. We tested whether caribou selection for forage and avoidance of risk was consistent between coarse (seasonal home range) and fine scales of selection. We found that local selection patterns predicted coarse scale selection patterns, indicating a close relationship between the drivers of selection at both spatial scales

    Collective Quadrupole Behavior in \u3csup\u3e106\u3c/sup\u3ePd

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    Excited states in 106Pd were studied with the (n,n′γ) reaction, and comprehensive information for excitations with spin ≤6ℏ was obtained. The data include level lifetimes in the femtosecond regime, spins and parities, transition multipolarities, and multipole mixing ratios, which allow the determination of reduced transition probabilities. The E2 decay strength to the low-lying states is mapped up to ≈2.4 MeV in excitation energy. The structures associated with quadrupole collectivity are elucidated and organized into bands

    Enhancement of Cytotoxicity of Enediyne Compounds by Hyperthermia: Effects of Various Metal Complexes on Tumor Cells

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    Enediyne natural products are a class of compounds that were recognized for their potential as chemotherapeutic agents many years ago, but found to be highly cytotoxic due to their propensity for low thermal activation. Bergman cyclization of the enediyne moiety produces a diradical intermediate, and may subsequently induce DNA damage and account for the extreme cytotoxicity. While difficulties in controlling the thermal cyclization reaction have limited the clinical use of cyclic enediynes, we have previously shown that enediyne activity, and thus toxicity at physiological temperatures can be modulated by metallation of acyclic enediynes. Furthermore, the cytotoxicity of "metalloenediynes" can be potentiated by hyperthermia. In this study, we characterized a suite of novel metallated enediyne motifs that usually induced little or no cytotoxicity when two different human cancer cell lines were treated with the compounds at 37°C, but showed a significant enhancement of cytotoxicity after cells were exposed to moderate hyperthermia during drug treatment. Cultured U-1 melanoma or MDA-231 breast cancer cells were treated with various concentrations of Cu, Fe and Zn complexes of the enediyne (Z)-N,N'-bis[1-pyridyl-2-yl-meth-(E)-ylidene]octa-4-ene-2,6-diyne-1,8-diamine (PyED) and clonogenic survival was assessed to determine the effects of the drugs at 37°C and 42.5°C. Toxicity at 37°C varied for each compound, but hyperthermia potentiated the cytotoxicity of each compound in both cell lines. Cytotoxicity was concentration-, time- and temperature-dependent. Heating cells during drug treatment resulted in enhanced apoptosis, but the role of cell cycle perturbation in the response of the cells to the drugs was less clear. Lastly, we showed that hyperthermia enhanced the number of DNA double-strand breaks (DSBs) induced by the compounds, and inhibited their repair after drug treatment. Thus, thermal enhancement of cytotoxicity may be due, at least in part, to the propensity of the enediyne moiety to induce DSBs, and/or a reduction in DSB repair efficiency. We propose that "tuning" of metalloenediyne toxicity through better-controlled reactivity could have potential clinical utility, since we envision that such compounds could be administered systemically as relatively non-toxic agents, but cytotoxicity could be enhanced in, and confined to a tumor volume when subjected to localized heating

    Characterization and initial demonstration of in vivo efficacy of a novel heat-activated metalloenediyne anti-cancer agent

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    Background: Enediynes are anti-cancer agents that are highly cytotoxic due to their propensity for low thermal activation of radical generation. The diradical intermediate produced from Bergman cyclization of the enediyne moiety may induce DNA damage and cell lethality. The cytotoxicity of enediynes and difficulties in controlling their thermal cyclization has limited their clinical use. We recently showed that enediyne toxicity at 37 °C can be mitigated by metallation, but cytotoxic effects of 'metalloenediynes' on cultured tumor cells are potentiated by hyperthermia. Reduction of cytotoxicity at normothermia suggests metalloenediynes will have a large therapeutic margin, with cell death occurring primarily in the heated tumor. Based on our previous in vitro findings, FeSO4-PyED, an Fe co-factor complex of (Z)-N,N'-bis[1-pyridin-2-yl-meth-(E)-ylidene]oct-4-ene-2,6-diyne-1,8-diamine, was prioritized for further in vitro and in vivo testing in normal human melanocytes and melanoma cells. Methods: Clonogenic survival, apopotosis and DNA binding assays were used to determine mechanisms of enhancement of FeSO4-PyED cytotoxicity by hyperthermia. A murine human melanoma xenograft model was used to assess in vivo efficacy of FeSO4-PyED at 37 or 42.5 °C. Results: FeSO4-PyED is a DNA-binding compound. Enhancement of FeSO4-PyED cytotoxicity by hyperthermia in melanoma cells was due to Bergman cyclization, diradical formation, and increased apoptosis. Thermal enhancement, however, was not observed in melanocytes. FeSO4-PyED inhibited tumor growth when melanomas were heated during drug treatment, without inducing normal tissue damage. Conclusion: By leveraging the unique thermal activation properties of metalloenediynes, we propose that localized moderate hyperthermia can be used to confine the cytotoxicity of these compounds to tumors, while sparing normal tissue
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