327 research outputs found

    How translational accuracy influences reading frame maintenance

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    Magnetic Bearing Retrofit Of A High Speed, Eight Stage Coker Compressor.

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    LecturePg. 81-90The design, integration, and implementation of a successful project to retrofit a high speed, eight stage centrifugal compressor with magnetic bearings and gas face seals is presented. The application is removal of light gases from the top of a fractionating tower in a refinery coker unit. The justification and reasons for the selection of the coker compressor retrofitted with magnetic bearings are discussed. The technical aspects of design, rotordynamics and operation of the old oil bearing and seal design to the retrofitted magnetic bearing and gas face seal designs are compared. The tuning of the magnetic bearings is also discussed along with startup and operation of the compressor running on magnetic bearings. The significant challenge associated with retrofitting a compressor with magnetic bearings previously running on oil bearings is addressed from a design consideration and rotordynamics point of view. The development of assembly/disassembly techniques and manufacturing methods special to a magnetic bearing retrofit are described. Also presented is the logistics of meeting the short lead time and narrow turnaround window of 12 days at the user's facilit

    Preliminary evidence for signature vocalizations among free-ranging narwhals (Monodon monoceros)

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    Author Posting. © Acoustical Society of America, 2006. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 120 (2006): 1695-1705, doi:10.1121/1.2226586.Animal signature vocalizations that are distinctive at the individual or group level can facilitate recognition between conspecifics and re-establish contact with an animal that has become separated from its associates. In this study, the vocal behavior of two free-ranging adult male narwhals (Monodon monoceros) in Admiralty Inlet, Baffin Island was recorded using digital archival tags. These recording instruments were deployed when the animals were caught and held onshore to attach satellite tags, a protocol that separated them from their groups. The signature content of two vocal categories was considered: (1) combined tonal/pulsed signals, which contained synchronous pulsatile and tonal content; (2) whistles, or frequency modulated tonal signals with harmonic energy. Nonparametric comparisons of the temporal and spectral features of each vocal class revealed significant differences between the two individuals. A separate, cross-correlation measure conducted on the whistles that accounted for overall contour shape and absolute frequency content confirmed greater interindividual compared to intraindividual differences. These data are consistent with the hypothesis that narwhals produce signature vocalizations that may facilitate their reunion with group members once they become separated, but additional data are required to demonstrate this claim more rigorously.I thank the WHOI Academic Programs office, the National Science Foundation Research Fellowship, and the National Defense Science and Engineering Graduate Fellowship for financial support. This field operation was funded by the Greenland Institute of Natural Resources, the National Environmental Research Institute, Department of Fisheries and Oceans, Nunavut Wildlife Management Board and the Danish Cooperation for the Environment in the Arctic (DANCEA). Additional logistical support was provided by the Polar Continental Shelf Project

    ‘O sibling, where art thou?’ – a review of avian sibling recognition with respect to the mammalian literature

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    Avian literature on sibling recognition is rare compared to that developed by mammalian researchers. We compare avian and mammalian research on sibling recognition to identify why avian work is rare, how approaches differ and what avian and mammalian researchers can learn from each other. Three factors: (1) biological differences between birds and mammals, (2) conceptual biases and (3) practical constraints, appear to influence our current understanding. Avian research focuses on colonial species because sibling recognition is considered adaptive where ‘mixing potential’ of dependent young is high; research on a wider range of species, breeding systems and ecological conditions is now needed. Studies of acoustic recognition cues dominate avian literature; other types of cues (e.g. visual, olfactory) deserve further attention. The effect of gender on avian sibling recognition has yet to be investigated; mammalian work shows that gender can have important influences. Most importantly, many researchers assume that birds recognise siblings through ‘direct familiarisation’ (commonly known as associative learning or familiarity); future experiments should also incorporate tests for ‘indirect familiarisation’ (commonly known as phenotype matching). If direct familiarisation proves crucial, avian research should investigate how periods of separation influence sibling discrimination. Mammalian researchers typically interpret sibling recognition in broad functional terms (nepotism, optimal outbreeding); some avian researchers more successfully identify specific and testable adaptive explanations, with greater relevance to natural contexts. We end by reporting exciting discoveries from recent studies of avian sibling recognition that inspire further interest in this topic

    Bringing Brotherly Love to Interprofessional Education - Creating a Curriculum of Simulation with Multidisciplinary Objectives

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    Objectives: Learners attending this presentation/workshop will: Discuss the current trends in an interprofessional education curriculum Explore the possible pinnacles and pitfalls in developing an IPE educational curriculum, including institutional support for IPE programs Acquire the skills to develop simulation cases that foster interprofessional objectives Interprofessional collaboration and teamwork among health care professionals is essential to provide safe, high quality patient care. Unfortunately, dismantling of the existing educational silos between disciplines is fraught with challenges. Success requires multidisciplinary commitment and leadership, and must occur early in each student’s educational training. Although gaining popularity, interprofessional education (IPE) and communication is not commonly a focus in all health care disciplines. Drexel University ‘s College of Medicine and College of Nursing and Health Professions have developed a successful IPE curriculum in Women’s Health, built on a foundation of simulation and communication. Occurring three days per academic year over the last five years, the curriculum engages OB/GYN and anesthesia residents, undergraduate nursing, nurse practitioner, nurse anesthesia, physician assistant and midwifery students in outpatient and inpatient scenarios with active participant communication activities that crescendo through the year. Expert faculty with enhanced credentials in multi-fidelity simulation, Debriefing with Good JudgmentTM, and TeamSTEPPSTM participate in faculty development and interactive curriculum review to provide learners with rigorous, life-like experiences while learning to appropriately give bad news, handle stressful situations, and discuss important health related issues in a collaborative environment. The Drexel University Partnership for Interprofessional Education (DU-PIE) has presented workshops and live demonstrations nationally to teach faculty and staff how to devise an interprofessional curriculum for their institutions. Pinnacles and pitfalls encountered during the development and roll out of the Drexel model can assist programs to sustain and further enrich IPE programs. This interactive workshop will consist of a brief presentation, a small group activity to assist faculty and professional staff in creating the building blocks of an IPE simulation program including identifying stakeholders, lobbying for administrative support, and developing simulation cases that incorporate multidisciplinary IPE objectives, and group debriefing to share gained insights

    PACT-mediated pkr activation acts as a hyperosmotic stress intensity sensor weakening osmoadaptation and enhancing inflammation

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    The inability of cells to adapt to increased environmental tonicity can lead to inflammatory gene expression and pathogenesis. The Rel family of transcription factors TonEBP and NF-κB p65 play critical roles in the switch from osmoadaptive homeostasis to inflammation, respectively. Here we identified PACT-mediated PKR kinase activation as a marker of the termination of adaptation and initiation of inflammation in Mus musculus embryonic fibroblasts. We found that high stress-induced PACT-PKR activation inhibits the interaction between NF-κB c-Rel and TonEBP essential for the increased expression of TonEBP-dependent osmoprotective genes. This resulted in enhanced formation of TonEBP/NF-κB p65 complexes and enhanced proinflammatory gene expression. These data demonstrate a novel role of c-Rel in the adaptive response to hyperosmotic stress, which is inhibited via a PACT/PKR-dependent dimer redistribution of the Rel family transcription factors. Our results suggest that inhibiting PACT-PKR signaling may prove a novel target for alleviating stress-induced inflammatory diseases

    Expression of Six1 in luminal breast cancers predicts poor prognosis and promotes increases in tumor initiating cells by activation of extracellular signal-regulated kinase and transforming growth factor-beta signaling pathways

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    Abstract Introduction Mammary-specific overexpression of Six1 in mice induces tumors that resemble human breast cancer, some having undergone epithelial to mesenchymal transition (EMT) and exhibiting stem/progenitor cell features. Six1 overexpression in human breast cancer cells promotes EMT and metastatic dissemination. We hypothesized that Six1 plays a role in the tumor initiating cell (TIC) population specifically in certain subtypes of breast cancer, and that by understanding its mechanism of action, we could potentially develop new means to target TICs. Methods We examined gene expression datasets to determine the breast cancer subtypes with Six1 overexpression, and then examined its expression in the CD24low/CD44+ putative TIC population in human luminal breast cancers xenografted through mice and in luminal breast cancer cell lines. Six1 overexpression, or knockdown, was performed in different systems to examine how Six1 levels affect TIC characteristics, using gene expression and flow cytometric analysis, tumorsphere assays, and in vivo TIC assays in immunocompromised and immune-competent mice. We examined the molecular pathways by which Six1 influences TICs using genetic/inhibitor approaches in vitro and in vivo. Finally, we examined the expression of Six1 and phosphorylated extracellular signal-regulated kinase (p-ERK) in human breast cancers. Results High levels of Six1 are associated with adverse outcomes in luminal breast cancers, particularly the luminal B subtype. Six1 levels are enriched in the CD24low/CD44+ TIC population in human luminal breast cancers xenografted through mice, and in tumorsphere cultures in MCF7 and T47D luminal breast cancer cells. When overexpressed in MCF7 cells, Six1expands the TIC population through activation of transforming growth factor-beta (TGF-β) and mitogen activated protein kinase (MEK)/ERK signaling. Inhibition of ERK signaling in MCF7-Six1 cells with MEK1/2 inhibitors, U0126 and AZD6244, restores the TIC population of luminal breast cancer cells back to that observed in control cells. Administration of AZD6244 dramatically inhibits tumor formation efficiency and metastasis in cells that express high levels of Six1 ectopically or endogenously. Finally, we demonstrate that Six1 significantly correlates with phosphorylated ERK in human breast cancers. Conclusions Six1 plays an important role in the TIC population in luminal breast cancers and induces a TIC phenotype by enhancing both TGF-β and ERK signaling. MEK1/2 kinase inhibitors are potential candidates for targeting TICs in breast tumors

    A waitlist-controlled trial of group cognitive behavioural therapy for depression and anxiety in Parkinson’s disease

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    Background: The aim of this study was to evaluate the efficacy of a group Cognitive Behavioural Therapy (CBT) treatment for depression and anxiety in Parkinson’s disease (PD). Methods: A waitlist-controlled trial design was used. Eighteen adults with PD and a comorbid DSM-IV-TR diagnosis of depression and/or anxiety were randomised to either Intervention (8-week group CBT treatment) or Waitlist (8-week clinical monitoring preceding treatment). The Depression, Anxiety, Stress Scale-21 (DASS-21) was the primary outcome. Assessments were completed at Time 1 (pretreatment), Time 2 (posttreatment/post-waitlist) and 1-month and 6-month follow-ups. Results: At Time 2, participants who received CBT reported greater reductions in depression (Mchange = -2.45) than Waitlist participants (Mchange = .29) and this effect was large, d = 1.12, p = .011. Large secondary effects on anxiety were also observed for CBT participants, d = .89, p = .025. All treatment gains were maintained and continued to improve during the follow-up period. At 6-month follow-up, significant and large effects were observed for both depression (d = 2.07) and anxiety (d = 2.26). Conclusions: Group CBT appears to be an efficacious treatment approach for depression and anxiety in PD however further controlled trials with larger numbers of participants are required

    MACSE: Multiple Alignment of Coding SEquences Accounting for Frameshifts and Stop Codons

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    Until now the most efficient solution to align nucleotide sequences containing open reading frames was to use indirect procedures that align amino acid translation before reporting the inferred gap positions at the codon level. There are two important pitfalls with this approach. Firstly, any premature stop codon impedes using such a strategy. Secondly, each sequence is translated with the same reading frame from beginning to end, so that the presence of a single additional nucleotide leads to both aberrant translation and alignment
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