On tuning a reactive silencer by varying the position of an internal membrane

A mode-matching method is used to investigate the performance of a two-dimensional, modified reactive silencer. The modification takes the form of a membrane which is attached to the internal walls of the expansion chamber parallel to the axis of the inlet/outlet ducts. The height of the membrane above the level of the inlet/outlet ducts can be varied and, by this means, the device is tuned. It is shown that the stopband produced by the silencer can be broadened and/or shifted depending upon the height to which the membrane is raised. Attention is focused on the efficiency of the device at low-frequencies - the regime where dissipative silencers are usually least effective. The potential use of the device as a component in a hybrid silencer for heating ventilation and air-conditioning (HVAC) ducting systems is discussed

A Study of Art Unions in the United States of America in the Nineteenth Century

During the first half of the nineteenth century in many cities in Germany, England and the United States, free and public galleries were opened to encourage the purchase of art works. Some sponsoring organizations were controlled by artists and some by interested lay persons. All of the sponsors hoped to educate the public and to elevate artistic taste as well as to sell works of art. Many of the organizations offered a premium in the form of a yearly engraving to induce interest and to promote membership. Often there was an annual distribution of paintings and other works of art by lottery. In several cities in the United States these organizations, which were called art unions, began offering memberships. The largest and most influential in the United States was the American Art-Union in New York. However, their success was short lived; by the mid-eighteen fifties, they had closed their doors

Mission Possible

The authors examine the impact of a program designed to encourage students to read popular business magazines. The results suggest that a reading program can improve student knowledge of current events, but that more work is needed to encourage students to attain timely knowledge of the current environment of business

Quality of Life and Autonomy in Emerging Adults with Early‐Onset Neuromuscular Disorders

Emerging adulthood is an important period in the development of one’s identity and autonomy. The ways in which identity and autonomy are viewed by emerging adults and how they impact quality of life (QoL) in individuals with early‐onset neuromuscular conditions is not yet known. This study focused on understanding and exploring relationships between self‐perceptions of emerging adulthood, autonomy, and QoL. Five previously validated measures were incorporated into an online survey and distributed to young adults with early‐onset neuromuscular conditions and unaffected controls. Topics explored included individuals’ views regarding their overall QoL, disease‐specific QoL, components of emerging adulthood, and autonomy. We found that a sense of higher disease impact was associated with a lower Overall General QoL. Additionally, perceptions of key autonomy factors “negativity” and “instability” were uniquely associated with Overall General QoL in the case group as compared to controls, whereas “attitudinal autonomy” (attaining the ability to plan and follow through with goals) was important to this age group regardless of health status. The specific factors of emerging adulthood and autonomy that were significantly correlated with Overall General QoL can be used for developing targeted counseling and interventions to improve QoL for individuals and their families.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146967/1/jgc40713.pd

Factors that impact on recruitment to randomised trials in health care : a qualitative evidence synthesis (Review)

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Partnering in a Pandemic: a Case Study on Designing Teaching and Learning Tools by Undergraduate and Graduate Medical Students with Academic Support

This case study reflects on the concept of student\u27s-as-partners in a project that took place during the Summer 2020, during the COVID-19 pandemic, involving nine students from two medical schools in Ireland (University College Dublin (UCD) and the Royal College of Surgeons in Ireland (RCSI) and makes a pedagogical case for partnership in learning and teaching in medical education. This virtual partnership project lasted three weeks under the supervision of practitioners from the National Maternity Hospital (NMH). The focus of this paper on one output from the project: designing and developing Multiple Choice Questions (MCQ) bank. This bank of MCQ questions were written by the students, based on national and international guidelines, then peer reviewed by the students before final review by academic staff and then integrated into the online teaching for the next iteration of the Obstetrics and Gynaecology module in September 2020. The reflections on this MCQ development work provides valuable insights on challenges and opportunities for medical students at both undergraduate and graduate level who are planning for collaborative partnerships as a component of their medical education, as well as academic-practitioners in medical education who are initiating student-staff partnership

HIV-1 infection induces changes in expression of cellular splicing factors that regulate alternative viral splicing and virus production in macrophages

BACKGROUND: Macrophages are important targets and long-lived reservoirs of HIV-1, which are not cleared of infection by currently available treatments. In the primary monocyte-derived macrophage model of infection, replication is initially productive followed by a decline in virion output over ensuing weeks, coincident with a decrease in the levels of the essential viral transactivator protein Tat. We investigated two possible mechanisms in macrophages for regulation of viral replication, which appears to be primarily regulated at the level of tat mRNA: 1) differential mRNA stability, used by cells and some viruses for the rapid regulation of gene expression and 2) control of HIV-1 alternative splicing, which is essential for optimal viral replication. RESULTS: Following termination of transcription at increasing times after infection in macrophages, we found that tat mRNA did indeed decay more rapidly than rev or nef mRNA, but with similar kinetics throughout infection. In addition, tat mRNA decayed at least as rapidly in peripheral blood lymphocytes. Expression of cellular splicing factors in uninfected and infected macrophage cultures from the same donor showed an inverse pattern over time between enhancing factors (members of the SR family of RNA binding proteins) and inhibitory factors (members of the hnRNP family). While levels of the SR protein SC35 were greatly up-regulated in the first week or two after infection, hnRNPs of the A/B and H groups were down-regulated. Around the peak of virus production in each culture, SC35 expression declined to levels in uninfected cells or lower, while the hnRNPs increased to control levels or above. We also found evidence for increased cytoplasmic expression of SC35 following long-term infection. CONCLUSION: While no evidence of differential regulation of tat mRNA decay was found in macrophages following HIV-1 infection, changes in the balance of cellular splicing factors which regulate alternative viral pre-mRNA splicing were observed. These changes correlated with changes in Tat expression and virus production and could play an important role in viral persistence in macrophages. This mechanism could provide a novel target for control of infection in this critical cell type, which would be necessary for eventual eradication of the virus from infected individuals

NKG7 enhances CD8+ T cell synapse efficiency to limit inflammation

Cytotoxic lymphocytes are essential for anti-tumor immunity, and for effective responses to cancer immunotherapy. Natural killer cell granule protein 7 (NKG7) is expressed at high levels in cytotoxic lymphocytes infiltrating tumors from patients treated with immunotherapy, but until recently, the role of this protein in cytotoxic lymphocyte function was largely unknown. Unexpectedly, we found that highly CD8+ T cell-immunogenic murine colon carcinoma (MC38-OVA) tumors grew at an equal rate in Nkg7+/+ and Nkg7-/- littermate mice, suggesting NKG7 may not be necessary for effective CD8+ T cell anti-tumor activity. Mechanistically, we found that deletion of NKG7 reduces the ability of CD8+ T cells to degranulate and kill target cells in vitro. However, as a result of inefficient cytotoxic activity, NKG7 deficient T cells form a prolonged immune synapse with tumor cells, resulting in increased secretion of inflammatory cytokines, including tumor necrosis factor alpha (TNF). By deleting the TNF receptor, TNFR1, from MC38-OVA tumors, we demonstrate that this hyper-secretion of TNF compensates for reduced synapse-mediated cytotoxic activity against MC38-OVA tumors in vivo, via increased TNF-mediated tumor cell death. Taken together, our results demonstrate that NKG7 enhances CD8+ T cell immune synapse efficiency, which may serve as a mechanism to accelerate direct cytotoxicity and limit potentially harmful inflammatory responses

Problem Gambling and Intimate Partner Violence A Systematic Review and Meta-Analysis

Author version made available in accordance with the publisher's policyThis study provides a systematic review of the empirical evidence related to the association between problem gambling and intimate partner violence (IPV). We identified 14 available studies in the systematic search (six for IPV victimisation and ten for IPV perpetration). Although there were some equivocal findings, we found that most of the available research suggests that there is a significant relationship between problem gambling and being a victim of IPV. There was more consistent evidence that there is a significant relationship between problem gambling and perpetration of IPV. Meta-analyses revealed that over one-third of problem gamblers report being victims of physical IPV (38.1%) or perpetrators of physical IPV (36.5%) and that the prevalence of problem gambling in IPV perpetrators is 11.3%. Although the exact nature of the relationships between problem gambling and IPV is yet to be determined, the findings suggest that less than full employment and clinical anger problems are implicated in the relationship between problem gambling and IPV victimisation and that younger age, less than full employment, clinical anger problems, impulsivity, and alcohol and substance use are implicated in the relationship between problem gambling and IPV perpetration. The findings highlight the need for treatment services to undertake routine screening and assessment of problem gambling, IPV, alcohol and substance use problems, and mental health issues, and provide interventions designed to manage this cluster of comorbid conditions. Further research is also required to investigate the relationship between problem gambling and violence that extends into the family beyond intimate partners

Factors that impact on recruitment to randomised trials in health care : a qualitative evidence synthesis (Protocol)

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