2,064 research outputs found

    When and where? Pathogenic Escherichia coli differentially sense host D-serine using a universal transporter system to monitor their environment

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    Sensing environmental stimuli is critically important for bacteria when faced with the multitude of adversities presented within the host. Responding appropriately to these signals and in turn integrating these responses into the regulatory network of the cell allows bacteria to control precisely when and where they should establish colonization. D-serine is an abundant metabolite of the human urinary tract but is a toxic metabolite for Escherichia coli that lack a D-serine tolerance locus. Enterohaemorrhagic E. coli (EHEC) cannot catabolize D-serine for this reason and colonize the large intestine specifically, an environment low in D-serine. EHEC can however use D-serine sensing to repress colonization thus signaling the presence of an unfavorable environment. In our recent work (Connolly, et al. PLoS Pathogens (2016) 12(1): e1005359), we describe the discovery of a functional and previously uncharacterized D-serine uptake system in E. coli. The genes identified are highly conserved in all E. coli lineages but are regulated differentially in unique pathogenic backgrounds. The study identified that EHEC, counter-intuitively, increase D-serine uptake in its presence but that this is a tolerated process and is used to increase the transcriptional response to this signal. It was also found that the system has been integrated into the transcriptional network of EHEC-specific virulence genes, demonstrating an important pathotype-specific adaptation of core genome components

    Tracking elusive cargo: Illuminating spatio-temporal type 3 effector protein dynamics using reporters

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    Type 3 secretion systems (T3SS) form an integral part of the arsenal of many pathogenic bacteria. These injection machines, together with their cargo of subversive effector proteins are capable of manipulating the cellular environment of the host in order to ensure persistence of the pathogen. In order to fully appreciate the functions of Type 3 effectors it is necessary to gain spatio-temporal knowledge of each effector during the process of infection. A number of genetic modifications have been exploited in order to reveal effector protein secretion, translocation and subsequent activity and localisation within host cells. In this review, we will discuss the many available approaches for tracking effector protein dynamics and discuss the challenges faced to improve the current technologies and gain a clearer picture of effector protein function

    Victim or whore: The similarities and differences between victim’s experiences of domestic violence and sex trafficking

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    This research review addresses the similarities and differences between domestic violence and sex trafficking victimization. While there is evidence that domestic violence and sex trafficking often cooccur, there is a large disparity in the understanding and interventions utilized by law enforcement as well as the services available for victims of each crime despite the considerable overlap of victimization. This article explores current research regarding domestic violence and sex trafficking with a focus towards identifying areas of overlap and areas distinct to sex trafficking

    AM800

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    In this paper, I will detail the film making techniques that my crew and I employed while making AM800, my thesis film at the University of New Orleans. I will detail the creative and technical steps we took, from the earliest stages of idea conceptualization to the final phases of post-production and screening. During my recounting of this process, I will discuss our creative goals, the challenges that we faced while achieving these goals, and the resulting product\u27s effectiveness as a narrative short film. The quality of the final product will be gauged through the results of test screenings and direct audience feedback

    AM800

    Get PDF
    In this paper, I will detail the film making techniques that my crew and I employed while making AM800, my thesis film at the University of New Orleans. I will detail the creative and technical steps we took, from the earliest stages of idea conceptualization to the final phases of post-production and screening. During my recounting of this process, I will discuss our creative goals, the challenges that we faced while achieving these goals, and the resulting product\u27s effectiveness as a narrative short film. The quality of the final product will be gauged through the results of test screenings and direct audience feedback

    A randomized controlled trial of PEEK versus titanium interference screws for anterior cruciate ligament reconstruction with 2-year follow-up

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    Purpose: To compare the clinical performance of ACL reconstruction with PEEK and titanium interference screws at 2 years and to evaluate a novel method of measuring tunnel volume. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: A total of 133 patients underwent arthroscopic ACL reconstruction with 4-strand hamstring autografts and were randomized to have titanium or PEEK interference screws for femoral and tibial tunnel fixation. At 2 years, subjective Lysholm and International Knee Documentation Committee scores were assessed and clinical examination performed. At 12 months, MRI was performed to assess graft incorporation and cyst formation, and a novel technique was employed to measure tunnel volumes. Results: There were no significant differences in graft rerupture rate, contralateral ACL rupture rate, subjective outcomes, or objective outcomes. In the titanium and PEEK groups, MRI demonstrated high overall rates of graft integration (96%-100% and 90%-93%, respectively) and ligamentization (89% and 84%) and low rates of synovitis (22% and 10%) and cyst formation (0%-18% and 13%-15%). There was a higher proportion of patients with incomplete graft integration within the femoral tunnel in the PEEK group as compared with the titanium group (10% vs 0%, P = .03); however, the authors suggest that metal artifact precluded proper assessment of the graft in the titanium group by MRI. Tunnel volumes also appeared to be equivalent in the 2 groups and were measured with a novel technique that was highly reproducible in the PEEK group secondary to the absence of flare. Conclusion: Two-year clinical analysis of PEEK interference screws for femoral and tibial fixation of ACL reconstructions showed equivalent clinical performance to titanium interference screws. Given the excellent mechanical characteristics, biological compatibility, and absence of metal artifact on MRI, PEEK has become our material of choice for interference screw fixation in ACL reconstruction

    Control freaks-signals and cues governing the regulation of virulence in attaching and effacing pathogens

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    Enterohaemorrhagic Escherichia coli (EHEC) mediates disease using a type 3 secretion system (T3SS), which is encoded on the locus of enterocyte effacement (LEE) and is tightly controlled by master regulators. This system is further modulated by a number of signals that help to fine-tune virulence, including metabolic, environmental and chemical signals. Since the LEE, and its master regulator, Ler, were established there have been numerous scientific advancements in understanding the regulation and expression of virulence factors in EHEC. This review will discuss the recent advancements in this field since our previous review, with a focus on transcriptional regulation of the LEE

    Process redesign of a surgical pathway improves access to cataract surgery for Aboriginal and Torres Strait Islander people in South East Queensland

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    The Institute for Urban Indigenous Health (IUIH) aimed to improve access to cataract surgery in urban South East Queensland (SEQ) for Indigenous Australians, without compromising clinical visual outcomes. The Penchansky and Levesque concept of access as the ‘fit’ between the patient’s needs and the ability of the system to meet those needs was used to inform the redesign of the mainstream cataract surgical pathway. The IUIH staff and community stakeholders mapped the traditional external cataract surgical pathway and then innovatively redesigned it to reduce the number of patients being removed by the system at key transition points. The integration of eye health within the primary health care (PHC) clinic has improved the continuity and coordination of care along the surgical pathway, and ensured the sustainability of collaborative partnerships with key external organisations. Audit data demonstrated a significant increase in utilisation of cataract surgical services after the process redesign. Previous studies have found that PHC models involving integration, coordination and continuity of care enhance patient health outcomes; however, the IUIH surgical model extends this to tertiary care. There is scope to apply this model to other surgical pathways and communities who experience access inequity

    Game of Tones: Faculty detection of GPT-4 generated content in university assessments

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    This study explores the robustness of university assessments against the use of Open AI's Generative Pre-Trained Transformer 4 (GPT-4) generated content and evaluates the ability of academic staff to detect its use when supported by the Turnitin Artificial Intelligence (AI) detection tool. The research involved twenty-two GPT-4 generated submissions being created and included in the assessment process to be marked by fifteen different faculty members. The study reveals that although the detection tool identified 91% of the experimental submissions as containing some AI-generated content, the total detected content was only 54.8%. This suggests that the use of adversarial techniques regarding prompt engineering is an effective method in evading AI detection tools and highlights that improvements to AI detection software are needed. Using the Turnitin AI detect tool, faculty reported 54.5% of the experimental submissions to the academic misconduct process, suggesting the need for increased awareness and training into these tools. Genuine submissions received a mean score of 54.4, whereas AI-generated content scored 52.3, indicating the comparable performance of GPT-4 in real-life situations. Recommendations include adjusting assessment strategies to make them more resistant to the use of AI tools, using AI-inclusive assessment where possible, and providing comprehensive training programs for faculty and students. This research contributes to understanding the relationship between AI-generated content and academic assessment, urging further investigation to preserve academic integrity
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