272 research outputs found
The European Men-Who-Have-Sex-With-Men Internet Survey (EMIS): Design and Methods
No full textCommunity-based opportunistic self-completion surveying for sexual health programming is common among men-who-have-sex-with-men (MSM) in Europe, being used to generate evidence of unmet prevention need, for behavioural surveillance and as a platform for advocating HIV precautions. However, comparing survey findings across Europe is difficult because of varying measures and recruitment designs, and surveying has not occurred in all countries. EMIS (the European Men-who-have-sex-with-men Internet Survey) aimed to develop a pan-European Internet survey on HIV-related male homosexual behaviours and prevention needs both to increase research capacity and to move towards harmonisation of existing systems. Six associated partners (APs) recruited another 77 collaborating partners from academia, public health and civil society across 35 countries. Partners' existing MSM surveys were collected and collated, producing a meta-survey which was discussed by all partners through rotating round-tables at a 2-day summit. Survey development continued iteratively through user piloting and partner feedback until the English language content was agreed. Transfer to an online survey application was followed by further testing before on-screen translation into 24 other languages, final testing and sign-off. The project's visual identity and promotional materials were developed in close collaboration with national leads, tailoring products to match country specific needs while maintaining an overall project identity. Five international MSM dating websites were contracted to send carefully crafted instant messages to members in a series of waves. The survey sought common ground with stakeholders and respondents by endorsing 'the best sex with the least harm' for MSM. Real-time monitoring of responses allowed targeted spending of the advertising budget to maximise coverage and depth of responses. Fieldwork occurred during June-August 2010. Over 184,469 responses were submitted of which 94.4 % were eligible. Partners in 38 countries were supplied with a national database of 100 or more respondents for national analysis and outputs, while the AP team proceeded on international comparisons among 174,209 respondents in 38 countries. EMIS demonstrated the feasibility of multi-country community-based MSM Internet surveying with limited public funding. The concept of 'the best sex with the least harm' provided a common ground for a diverse range of stakeholders to collaborate. Meaningful involvement of a large number of collaborators in the survey design, its visual identity and in promotional strategies ensured unprecedented coverage and depth of recruitment. Flexible planning was essential and a patchwork of recruitment was required across a range of commercial and community partners. Careful design, piloting and presentation ensured the survey was acceptable and had both authority and perceived community benefit. © 2013 The Author(s)
A Simulation Method for Design and Development of Magnetic Shape Memory Actuators
No full textThe systems/products and their design processes have become more and more complicated due to the fact that their requirements in terms of function, durability, reliability and energy efficiency have been increased significantly and that their leading time has to be short and their materials cost has to be low. To meet these requirements, individual parts and subsystems have to offer increased functionality and efficiency themselves. It has been found that smart materials, such as piezo ceramics or various shape memory alloys as well as less known dielectric elastomers or magnetic shape memory alloys, offer ideal preconditions to fulfil such requirements. Among the various shape memory alloys, the Magnetic Shape Memory (MSM) alloy is a kind of smart material that can elongate and contract in a magnetic field. Based on the MSM alloy a new type of smart electromagnetic actuators have been designed and developed. This kind of actuator exhibits the features above. Typically, the MSM material is a monocrystalline Ni-Mn-Ga alloy, which has the ability to change its size or shape very fast and many million times repeatedly. State-of-the-art alloys are able to achieve a magnetic field induced strain of up to 12%. The magneto-mechanical characteristic of MSM alloys is being constantly improved. However, as far as the author is aware, there are no efficient and commercially available tools for engineers to design MSM-based actuators. To achieve this, simulation tools for design are indispensable. This thesis is dedicated to this task.
In this PhD thesis, new design and simulation techniques for MSM-based actuators have been studied. In particular, three simulation methods have been proposed. These three methods extend standard magneto-static FEM simulation techniques by taking into account the magneto-mechanical coupling and the magnetic anisotropy of the MSM materials. They differ in terms of the necessary a priori alloy characterisation (i.e., measurement effort), computational complexity and consequent computing time. The magneto-mechanical characteristics of the MSM material are a necessary and fundamental ingredient for this type of simulation. However, the characterisation of the MSM materials is a very challenging task and requires specific modifications to standard measurement approaches. So, in this thesis, some specific measurement methods of the magneto-mechanical characteristics of the MSM materials have been proposed, designed and developed. It is described how existing measurement instruments can be modified to measure the unique magneto-mechanical characteristics of MSM, so they are applicable and with practical values. Various tests have been carried out to validate the new methods and the necessary characterisations of the properties of MSM materials have been performed, such as the measurement of the permeability of MSM under a defined stress during elongation. The new measurement results have been analysed and the findings have been used to design and develop the simulation methods. The three simulation methods can be used to predict and optimise the current-elongation behaviour of an MSM element under the load of a mechanical stress while excited by a magnetic field. Extensive experiments have been carried out to validate these three simulation methods. The results show that the three methods are relatively simple but, at the same time, very effective means to model, predict and optimise the properties of an MSM actuator using finite element tools. In addition, the experiment results have also shown that the simulation methods can be used to gain some deep insights into the magneto-mechanical interaction between the MSM element and the electromagnetic actuator. In this thesis an evolutionary algorithm which works together with the simulation methods has been developed to achieve individual optimised solutions in very short times.
In summary, from the experiment results, it has been found that the measurements and simulation methods proposed and developed in this thesis; enable designers to perform simulations for a high-quality actuator design based on the magneto-mechanical properties of MSM alloys. This is the first time that a MSM can be characterised for simulation purposes in a fast and precise way to predict MSM and electromagnetic actuator interactions and identify and optimise the design parameters of such actuators.
However, these simulation methods are strongly dependent on the measurement of the magneto-mechanical characteristics of magnetic shape memory alloys, whose precision can be further improved. To reach commercial success as well higher precision in the simulation prediction, further achievements in the field of material science (e.g. smoothness of mechanical curves) are also necessary
IDENTIFYING THE FACTORS THAT IMPACT THE HIV/AIDS EPIDEMIC AMONG MSM IN THE PHILIPPINES
No full textabstract: This study identifies the factors impacting the growing HIV/AIDS epidemic among men who have sex with men (MSM) in the Philippines. Ten studies and three external reviews concerning HIV, MSM, and the HIV/AIDS epidemic in the Philippines and Southeast Asia from 2009 to 2015 were analyzed to find common patterns in the literature and identify the factors that impact the HIV prevalence among MSM in the Philippines. Secondary analysis of the literature identified the following as influencing factors: HIV prevalence patterns, the accessibility of HIV-related health education, the engagement of MSM in health-seeking behaviors related to HIV, perceptions of HIV risk among MSM, and the influence of culture and religion in the Philippines. These factors lead to an increase in the overall HIV prevalence among MSM in the Philippines by increasing the potential of HIV transmission among the community as a whole and increasing the vulnerability of individual MSM to HIV infection. These factors were also found to be interconnected, each having an impact on the other. The lack of sexual health education coupled with the barriers to HIV-related health care are especially prominent interconnected issues concerning the prevention of HIV transmission. There needs to be further research in investigating which specific barriers that prevent the engagement and retention of HIV positive men in the Philippines in HIV care and related services after diagnosis in order to reduce the overall population viral load of HIV-positive MSM. Examining the issues concerning engagement in health care among HIV positive MSM could aid in overcoming the barriers to health care faced by MSM as well as addressing the increasing HIV prevalence among MSM in the Philippines
Protective effects of methylsulfonylmethane (MSM) on barrier function injury of porcine intestinal epithelial cells (IPEC-J2) induced by lipopolysaccharide (LPS)
No full textMethylsulfonylmethane (MSM) is a natural organic sulfur component, which has anti-inflammatory and antioxidant properties. In this study, IPEC-J2 cells model were used to investigate the effect of MSM on lipopolysaccharide (LPS)-induced porcine intestinal epithelium barrier damage. The results of cell cycle showed that the cells in the G2/M phase were decreased significantly with the supplementation of 300 mM MSM (PThe presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author
HPV infections among young MSM visiting sexual health centers in the Netherlands:Opportunities for targeted HPV vaccination
No full textIntroduction: In 2009, girls-only HPV16/18 vaccination was introduced in the Netherlands which has achieved 46-61% uptake. Heterosexual men have benefitted from herd protection, but it is unknown whether men who have sex with men (MSM) also benefit from herd effects of the girls-only HPV16/18 vaccination program. Because MSM bear a high HPV-related disease burden, countries might consider targeted vaccination for MSM. To study possible herd effects and prior HPV exposure at a potential moment of vaccination, we assessed trends in the HPV prevalence and proportions (sero)negative for the various vaccine types among young MSM visiting sexual health centers (SHCs).Methods: We used data from MSM included in PASSYON study years 2009-2017. In this biennial cross-sectional study among visitors of SHCs aged 16-24 years, MSM provided a penile and anal swab for HPV DNA testing (including vaccine types HPV6/11/16/18/31/33/45/52/58) and blood for HPV antibody testing (HPV16/18/31/33/45/52/58).Results: In total 575 MSM were included, with a median of 22 years of age and 15 lifetime sex partners and 3.5% HIV positive. Trends in penile or anal HPV prevalence during 2009-2017 were statistically non-significant for all vaccine types. Of the 455 MSM with a penile and anal swab, 360 (79%), 283 (62%) and 242 (53%) were HPV DNA negative at both anatomical sites for HPV16/18, HPV6/11/16/18 and HPV6/11/16/18/31/33/45/52/58 respectively. Among MSM who were HPV16/18 and HPV16/18/31/33/45/52/58 DNA negative and were tested for serology (n = 335 and 279 respectively), 82% and 71% were also seronegative for the respective types.Discussion: There were no significant declines in the HPV prevalence among MSM up to eight years after introduction of girls-only HPV16/18 vaccination, indicating that MSM are unlikely to benefit largely from herd effects from girls-only vaccination. Most MSM were vaccine-type DNA negative and seronegative, suggesting that vaccination of young MSM visiting SHCs could still be beneficial. (C) 2020 The Author(s). Published by Elsevier Ltd.</p
HPV infections among young MSM visiting sexual health centers in the Netherlands: opportunities for targeted HPV vaccination
No full textIntroduction: In 2009, girls-only HPV16/18 vaccination was introduced in the Netherlands which has achieved 46-61% uptake. Heterosexual men have benefitted from herd protection, but it is unknown whether men who have sex with men (MSM) also benefit from herd effects of the girls-only HPV16/18 vaccination program. Because MSM bear a high HPV-related disease burden, countries might consider targeted vaccination for MSM. To study possible herd effects and prior HPV exposure at a potential moment of vaccination, we assessed trends in the HPV prevalence and proportions (sero)negative for the various vaccine types among young MSM visiting sexual health centers (SHCs).Methods: We used data from MSM included in PASSYON study years 2009-2017. In this biennial cross-sectional study among visitors of SHCs aged 16-24 years, MSM provided a penile and anal swab for HPV DNA testing (including vaccine types HPV6/11/16/18/31/33/45/52/58) and blood for HPV antibody testing (HPV16/18/31/33/45/52/58).Results: In total 575 MSM were included, with a median of 22 years of age and 15 lifetime sex partners and 3.5% HIV positive. Trends in penile or anal HPV prevalence during 2009-2017 were statistically non-significant for all vaccine types. Of the 455 MSM with a penile and anal swab, 360 (79%), 283 (62%) and 242 (53%) were HPV DNA negative at both anatomical sites for HPV16/18, HPV6/11/16/18 and HPV6/11/16/18/31/33/45/52/58 respectively. Among MSM who were HPV16/18 and HPV16/18/31/33/45/52/58 DNA negative and were tested for serology (n = 335 and 279 respectively), 82% and 71% were also seronegative for the respective types.Discussion: There were no significant declines in the HPV prevalence among MSM up to eight years after introduction of girls-only HPV16/18 vaccination, indicating that MSM are unlikely to benefit largely from herd effects from girls-only vaccination. Most MSM were vaccine-type DNA negative and seronegative, suggesting that vaccination of young MSM visiting SHCs could still be beneficial. (C) 2020 The Author(s). Published by Elsevier Ltd
Hepatitis A outbreak among MSM in Berlin due to low vaccination coverage: Epidemiology, management, and successful interventions
No full textObjectives: To describe the characteristics of a large hepatitis A virus (HAV) outbreak among men who have sex with men (MSM) in Berlin and to assess the impact of measures implemented. Methods: Cases of laboratory-confirmed, symptomatic HAV infection notified in Berlin, Germany between August 2016 and February 2018 were analysed using routine and enhanced surveillance data including genotyping results. Several studies involving different groups of participants were conducted to further investigate the outbreak, including surveys on knowledge and practices of HAV vaccination among physicians and vaccination coverage and determinants of vaccination status among MSM. The measures implemented were categorized by target group in a Gantt chart. To assess their impact, health insurance data on HAV vaccination uptake were analysed, comparing Berlin and other federal states. Results: During the outbreak period, a total of 222 cases were reported (of which 91 were sequence confirmed), with a peak in case numbers in January 2017. Physicians were aware of the existing vaccination recommendations, but vaccination coverage among 756 MSM was low, with 32.7% being completely vaccinated and 17.3% being incompletely vaccinated before 2017. HAV vaccination before 2017 was associated with being born in Germany (odds ratio 2.36) and HIV-positive (odds ratio 1.80). HAV monovalent vaccination uptake increased by 164% from 2016 to 2017 among males in Berlin, compared to 7% in other federal states. Conclusions: Multiple measures targeting the MSM community, physicians, and public health to increase HAV vaccination uptake were successfully implemented. To prevent future HAV outbreaks, we recommend monitoring vaccination coverage among MSM, promoting awareness of existing recommendations among physicians, and ensuring access for foreign-born and young MSM. (c) 2020 The Author(s). Published by Elsevier Ltd on behalf of International Society for Infectious Diseases. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Experiences of stigma and the risk of HIV and other HIV related outcomes among men who have sex with men (MSM) in the United States
No full textGay, bisexual, and other men who have sex with men (MSM) are the population most affected by HIV in the United States. When we look at geographic regions across the United States, among persons living with HIV, the largest percentage of persons with undiagnosed HIV infection is in the Midwest (15.4%), followed by the South (15.1%), West (14.4%), and Northeast (9.5%). Although stigma has been well documented among MSM, the literature is largely fragmented in the United States, on the risk of HIV infection, access to prevention, care and treatment services, and its associated health outcomes. Studies have been conducted to assess the prevalence of these undisclosed infections however, at present, there is no published study comparing and evaluating the association of stigma and undiagnosed HIV infections among MSM across the major cities in United States. Specific aims of this dissertation are: (1) To do a scoping review of the literature that documents links between stigma and the risk of HIV, access to HIV prevention, care and treatment services, and related health outcomes in key population specifically among HIV-positive and HIV-negative MSM in the United States; (2) To assess the proportion and distribution of undiagnosed HIV infection in MSM and to further examine the aggregate relationship between experienced stigma, perceived HIV stigma and undiagnosed HIV infections among this high-risk population while making comparisons among 8 different tiered cities in the United States; (3) Based on the results from the second study, to then compare the demographic characteristics and risk factors of two diverse cities in the United States in order to identify whether location/ social context and stigma play a role in undiagnosed HIV infections among MSM.Ph.D.Includes bibliographical reference
Template-Assisted Mechanosynthesis Leading to Benchmark Energy Efficiency and Sustainability in the Production of Bifunctional Fe-N-C Electrocatalysts
No full textEfficient and sustainable synthesis of performant metal/nitrogen-doped carbon (M-N-C) catalysts for oxygen reduction and evolution reactions (ORR/OER) is vital for the global switch to green energy technologies-fuel cells and metal-air batteries. This study reports a solid-phase template-assisted mechanosynthesis of Fe-N-C, featuring low-cost and sustainable FeCl3, 2,4,6-tri(2-pyridyl)-1,3,5-triazine (TPTZ), and NaCl. A NaCl-templated Fe-TPTZ metal-organic material was formed using facile liquid-assisted grinding/compression. With NaCl, the Fe-TPTZ template-induced stability allows for a rapid, thus, energy-efficient pyrolysis. Among the produced materials, 3D-FeNC-LAG exhibits remarkable performance in ORR (E1/2 = 0.85 V and Eonset = 1.00 V), OER (Ej=10 = 1.73 V), and in the zinc-air battery test (power density of 139 mW cm-2). The multilayer stream mapping (MSM) framework is presented as a tool for creating a sustainability assessment protocol for the catalyst production process. MSM employs time, cost, resource, and energy efficiency as technoeconomic sustainability metrics to assess the potential upstream impact. MSM analysis shows that the 3D-FeNC-LAG synthesis exhibits 90% overall process efficiency and 97.67% cost efficiency. The proposed synthetic protocol requires 2 times less processing time and 3 times less energy without compromising the catalyst efficiency, superior to the most advanced methods.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Team Peyman Taher
Statistical process development and optimization of gallium arsenide MESFET-MSM optoelectronic integrated circuits
No full textU of I OnlyItem marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding ([email protected]) on 2011-05-07T14:52:34Z
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Reason: ETDs are only available to UIUC Users without author permissionETDs are only available to UIUC Users without author permission"In the last ten years, the emergence of optoelectronic technology has revolutionized the communications industry. Unfortunately, this technology is expensive and is thus only affordable to major telecommunication carriers, that is, phone companies. To further expand the applications of optoelectronic technology from ""long-haul"" communication to short-distance optical interconnects, the development of cost-effective devices for high performance computing and communication applications is urgently needed."OptoElectronic Integrated Circuits (OEIC) composed of photodetectors and lasers on the same substrate with transistors promise several advantages over their hybrid counterparts; among these are enhanced performance and low cost. To address the problems or barriers which integration technology faces, the Gallium-Arsenide (GaAs) Metal-Semiconductor Field Effect Transistor (MESFET) and Metal-Semiconductor-Metal (MSM) technology provide a reasonable way for achieving this end. The MSM photodetector structure, which consists of a set of interdigitated metal fingers, is notably compatible with the MESFET process making monolithic integration possible.The focus of this thesis work is on the process development and optimization of GaAs MESFET-MSM based integrated circuits using a statistical experimental design technique. This technique provides an efficient and reliable way for both developing a new process and optimizing an existing one, when a large number of process variables are involved. Statistically significant transfer characteristics of key process modules in this GaAs MESFET-MSM process are obtained and used for process optimization. The optimal process is obtained by both maximizing the device and circuit performance and minimizing the transmitted variations from the process to the finished circuits. Therefore, a robust process is achieved in the sense that the process variations are least transmitted to the finished product.Made available in DSpace on 2011-05-07T13:16:21Z (GMT). No. of bitstreams: 2
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