Energy Systems Laboratory: Building a Model Repository Collection

The Energy Systems Laboratory (ESL) is a division of the Texas Engineering Experiment Station and part of the Texas A&M University System. First established in 1939, the ESL maintains a testing laboratory on the Riverside Campus in Bryan, Texas, and offices on the main campus of Texas A&M. The group consists of five faculty members from the Department of Mechanical Engineering, as well as three faculty members from the Departments of Architecture and Construction Science. The lab currently employs approximately 120 staff members, including mechanical engineers, computer science graduates, lab technicians, support staff, and graduate and undergraduate students. The Lab focuses on energy-related research, energy efficiency, and emissions reduction, and has a total annual income for external research and testing exceeding $4.5 million. With energy research and policy at the forefront of public discussion, both academic and political, the urgency of making this research publicly available is very high. The Energy Systems Laboratory collection in the Texas A&M Digital Repository is unique in a number of ways. After first contacting the library in March 2005, the ESL became one of Texas A&M's earliest adopters of the repository. The collection is very diverse, and contains conference proceedings, published articles, technical reports, and electronic theses and dissertations produced by students affiliated with the ESL. The ESL is also the first repository client to take the initiative of assigning staff members to learn the batch loading process for themselves, both relieving library staff of the burden and allowing the collection to expand even more rapidly. The collection has also successfully made the transition, despite some challenges, from the original DSpace interface to the Manakin-themed repository now in place. After three years, the collection remains one of the largest collections in the system, continues to grow as more of the group's research and publications are added to the collection, and is held forth as a model collection to prospective repository clients in the Texas A&M community. This is a testament to the Energy Systems Laboratory's dedication to the building of their repository collection, and their clear understanding of the advantages of open access. This presentation will discuss the excellent working relationship built between the Energy System Laboratory and the library, and how such relationships can be fostered with other collections as the repository expands. It will also recount the events leading up to the ESL's original adoption of the repository, and will chronicle the evolution of the repository collection, the addition of new content, the transition and adaptation to new technology, the copyright and other challenges faced, and the group's future needs for additional tools and services

Transmission reduction, health benefits, and upper-bound costs of interventions to improve retention on antiretroviral therapy: a combined analysis of three mathematical models

BACKGROUND: In this so-called treat-all era, antiretroviral therapy (ART) interruptions contribute to an increasing proportion of HIV infections and deaths. Many strategies to improve retention on ART cost more than standard of care. In this study, we aimed to estimate the upper-bound costs at which such interventions should be adopted. METHODS: In this combined analysis, we compared the infections averted, disability-adjusted life-years (DALYs) averted, and upper-bound costs of interventions that improve ART retention in three HIV models with diverse structures, assumptions, and baseline settings: EMOD in South Africa, Optima in Malawi, and Synthesis in sub-Saharan African low-income and middle-income countries (LMICs). We modelled estimates over a 40-year time horizon, from a baseline of Jan 1, 2022, when interventions would be implemented, to Jan 1, 2062. We varied increment of ART retention (25%, 50%, 75%, and 100% retention), the extent to which interventions could be targeted towards individuals at risk of interrupting ART, and cost-effectiveness thresholds in each setting. FINDINGS: Despite simulating different settings and epidemic trends, all three models produced consistent estimates of health benefit (ie, DALYs averted) and transmission reduction per increment in retention. The range of estimates was 1·35-3·55 DALYs and 0·12-0·20 infections averted over the 40-year time horizon per additional person-year retained on ART. Upper-bound costs varied by setting and intervention effectiveness. Improving retention by 25% among all people receiving ART, regardless of risk of ART interruption, gave an upper-bound cost per person-year of US$2-6 in Optima (Malawi),$43-68 in Synthesis (LMICs in sub-Saharan Africa), and $28-180 in EMOD (South Africa). A maximally targeted and effective retention intervention had an upper-bound cost per person-year of US$93-223 in Optima (Malawi), $871-1389 in Synthesis (LMICs in sub-Saharan Africa), and$1013-6518 in EMOD (South Africa). INTERPRETATION: Upper-bound costs that could improve ART retention vary across sub-Saharan African settings and are likely to be similar to or higher than was estimated before the start of the treat-all era. Upper-bound costs could be increased by targeting interventions to those most at risk of interrupting ART. FUNDING: Bill & Melinda Gates Foundation

Public health benefits of shifting from inpatient to outpatient TB care in Eastern Europe: optimising TB investments in Belarus, the Republic of Moldova, and Romania

Background: High rates of drug-resistant tuberculosis (DR TB) continue to threaten public health, especially in Eastern Europe. Costs for treating DR TB are substantially higher than treating drug-susceptible TB, and higher yet if DR TB services are delivered in hospital. Therefore, countries are encouraged to transition from inpatient to ambulatory-focused TB care, which has been shown to have non-inferior health outcomes. / Methods: Allocative efficiency analyses were conducted for three countries in Eastern Europe, Belarus, the Republic of Moldova, and Romania to minimise a combination of active TB cases, prevalence of active TB, and TB-related deaths by 2035. These mathematical optimisations were carried out using Optima TB, a dynamical compartmental model of TB transmission. The focus of this study was to project the health and financial gains that could be realised if TB service delivery shifted from hospital to ambulatory-based care. / Findings: These analyses show that transitioning from inpatient to ambulatory TB care could reduce treatment costs by 5%−31% or almost 35 million US dollars across these three countries without affecting the quality of care. Improved TB outcomes could be achieved without additional spending by reinvesting these potential savings in cost-effective prevention and diagnosis interventions. / Conclusions: National governments should examine barriers delaying the adoption of outpatient DR TB care and consider the lost opportunities caused by delays in switching to more efficient and effective treatment modes

Public health benefits of shifting from hospital-focused to ambulatory TB care in Eastern Europe: Optimising TB investments in Belarus, the Republic of Moldova, and Romania

High rates of drug-resistant tuberculosis (DR-TB) continue to threaten public health, especially in Eastern Europe. Costs for treating DR-TB are substantially higher than treating drug-susceptible TB, and higher yet if DR-TB services are delivered in hospital. The WHO recommends that multidrug-resistant (MDR) TB be treated using mainly ambulatory care, shown to have non-inferior health outcomes, however, there has been a delay to transition away from hospital-focused MDR-TB care in certain Eastern European countries. Allocative efficiency analyses were conducted for three countries in Eastern Europe, Belarus, the Republic of Moldova, and Romania, to minimise a combination of TB incidence, prevalence, and mortality by 2035. A primary focus of these studies was to determine the health benefits and financial savings that could be realised if DR-TB service delivery shifted from hospital-focused to ambulatory care. Here we provide a comprehensive assessment of findings from these studies to demonstrate the collective benefit of transitioning from hospital-focused to ambulatory TB care, and to address common regional considerations. We highlight that transitioning from hospital-focused to ambulatory TB care could reduce treatment costs by 20% in Romania, 24% in Moldova, and by as much as 40% in Belarus or almost 35 million US dollars across these three countries by 2035 without affecting quality of care. Improved TB outcomes could be achieved, however, without additional spending by reinvesting these savings in higher-impact TB diagnosis and more efficacious DR-TB treatment regimens. We found commonalities in the large portion of TB cases treated in hospital across these three regional countries, and similar obstacles to transitioning to ambulatory care. National governments in the Eastern European region should examine barriers delaying adoption of ambulatory DR-TB care and consider lost opportunities caused by delays in switching to more efficient treatment modes

Measuring HIV acquisitions among partners of key populations: estimates from HIV transmission dynamic models

BACKGROUND: Key populations (KPs), including female sex workers (FSWs), gay men and other men who have sex with men (MSM), people who inject drugs (PWID), and transgender women (TGW) experience disproportionate risks of HIV acquisition. The UNAIDS Global AIDS 2022 Update reported that one-quarter of all new HIV infections occurred among their non-KP sexual partners. However, this fraction relied on heuristics regarding the ratio of new infections that KPs transmitted to their non-KP partners to the new infections acquired among KPs (herein referred to as "infection ratios"). We recalculated these ratios using dynamic transmission models.SETTING: One hundred seventy-eight settings (106 countries).METHODS: Infection ratios for FSW, MSM, PWID, TGW, and clients of FSW were estimated from 12 models for 2020.RESULTS: Median model estimates of infection ratios were 0.7 (interquartile range: 0.5-1.0; n = 172 estimates) and 1.2 (0.8-1.8; n = 127) for acquisitions from FSW clients and transmissions from FSW to all their non-KP partners, respectively, which were comparable with the previous UNAIDS assumptions (0.2-1.5 across regions). Model estimates for female partners of MSM were 0.5 (0.2-0.8; n = 20) and 0.3 (0.2-0.4; n = 10) for partners of PWID across settings in Eastern and Southern Africa, lower than the corresponding UNAIDS assumptions (0.9 and 0.8, respectively). The few available model estimates for TGW were higher [5.1 (1.2-7.0; n = 8)] than the UNAIDS assumptions (0.1-0.3). Model estimates for non-FSW partners of FSW clients in Western and Central Africa were high (1.7; 1.0-2.3; n = 29).CONCLUSIONS: Ratios of new infections among non-KP partners relative to KP were high, confirming the importance of better addressing prevention and treatment needs among KP as central to reducing overall HIV incidence.</p

How should HIV resources be allocated? Lessons learnt from applying Optima HIV in 23 countries.

INTRODUCTION: With limited funds available, meeting global health targets requires countries to both mobilize and prioritize their health spending. Within this context, countries have recognized the importance of allocating funds for HIV as efficiently as possible to maximize impact. Over the past six years, the governments of 23 countries in Africa, Asia, Eastern Europe and Latin America have used the Optima HIV tool to estimate the optimal allocation of HIV resources. METHODS: Each study commenced with a request by the national government for technical assistance in conducting an HIV allocative efficiency study using Optima HIV. Each study team validated the required data, calibrated the Optima HIV epidemic model to produce HIV epidemic projections, agreed on cost functions for interventions, and used the model to calculate the optimal allocation of available funds to best address national strategic plan targets. From a review and analysis of these 23 country studies, we extract common themes around the optimal allocation of HIV funding in different epidemiological contexts. RESULTS AND DISCUSSION: The optimal distribution of HIV resources depends on the amount of funding available and the characteristics of each country's epidemic, response and targets. Universally, the modelling results indicated that scaling up treatment coverage is an efficient use of resources. There is scope for efficiency gains by targeting the HIV response towards the populations and geographical regions where HIV incidence is highest. Across a range of countries, the model results indicate that a more efficient allocation of HIV resources could reduce cumulative new HIV infections by an average of 18% over the years to 2020 and 25% over the years to 2030, along with an approximately 25% reduction in deaths for both timelines. However, in most countries this would still not be sufficient to meet the targets of the national strategic plan, with modelling results indicating that budget increases of up to 185% would be required. CONCLUSIONS: Greater epidemiological impact would be possible through better targeting of existing resources, but additional resources would still be required to meet targets. Allocative efficiency models have proven valuable in improving the HIV planning and budgeting process

Getting it right when budgets are tight: Using optimal expansion pathways to prioritize responses to concentrated and mixed HIV epidemics

Published: October 3, 2017Background: Prioritizing investments across health interventions is complicated by the nonlinear relationship between intervention coverage and epidemiological outcomes. It can be difficult for countries to know which interventions to prioritize for greatest epidemiological impact, particularly when budgets are uncertain. Methods: We examined four case studies of HIV epidemics in diverse settings, each with different characteristics. These case studies were based on public data available for Belarus, Peru, Togo, and Myanmar. The Optima HIV model and software package was used to estimate the optimal distribution of resources across interventions associated with a range of budget envelopes. We constructed “investment staircases”, a useful tool for understanding investment priorities. These were used to estimate the best attainable cost-effectiveness of the response at each investment level. Findings: We find that when budgets are very limited, the optimal HIV response consists of a smaller number of ‘core’ interventions. As budgets increase, those core interventions should first be scaled up, and then new interventions introduced. We estimate that the cost-effectiveness of HIV programming decreases as investment levels increase, but that the overall cost-effectiveness remains below GDP per capita. Significance: It is important for HIV programming to respond effectively to the overall level of funding availability. The analytic tools presented here can help to guide program planners understand the most cost-effective HIV responses and plan for an uncertain future.Robyn M. Stuart, Cliff C. Kerr, Hassan Haghparast-Bidgoli, Janne Estill, Laura Grobicki, Zofia Baranczuk, Lorena Prieto, Vilma Montañez, Iyanoosh Reporter, Richard T. Gray, Jolene Skordis-Worrall, Olivia Keiser, Nejma Cheikh, Krittayawan Boonto, Sutayut Osornprasop, Fernando Lavadenz, Clemens J. Benedikt, Rowan Martin-Hughes, S. Azfar Hussain, Sherrie L. Kelly, David J. Kedziora, David P. Wilso

Factors Affecting Human Force Perception and Performance in Haptic-Enabled Virtual Environments

Haptic technology enables computer users to touch and/or manipulate virtual objects in virtual environments (VEs). Similar to other human-in-the-loop applications, haptic applications require interactions between humans and computers. Thus, human-factors studies are required to recognize the limitations and capabilities of the user. This thesis establishes human-factors criteria to improve various haptic applications such as perception-based haptic compression techniques and haptic-enabled computer-aided design (CAD). Today, data compression plays a significant role in the transmission of haptic information since the efficient use of the available bandwidth is a concern. Most lossy haptic compression techniques rely on the limitations of human force perception, and this is used in the design of perception-based haptic compression techniques. Researchers have studied force perception when a user is in static interaction with a stationary object. This thesis focuses on cases where the human user and the object are in relative motion. The limitations of force perception are quantified using psychophysical methods, and the effects of several factors, including user hand velocity and sensory adaptation, are investigated. The results indicate that fewer haptic details need to be calculated or transmitted when the user's hand is in motion. In traditional CAD systems, users usually design virtual prototypes using a mouse via their vision system only, and it is difficult to design curved surfaces due to the number, shape, and position of the curves. Adding haptics to CAD systems enables users to explore and manipulate virtual objects using the sense of touch. In addition, human performance is important in CAD environments. To maintain the accuracy, active haptic manipulation of the user response can be incorporated in CAD applications. This thesis investigates the effect of forces on the accuracy of movement in VEs. The results indicate that factors such as the base force intensity and force increment/decrement can be incorporated in the control of users' movements in VEs. In other words, we can pull/push the users' hands by increasing/decreasing the force without the users being aware of it

Cost-effectiveness of voluntary medical male circumcision for HIV prevention across sub-Saharan Africa : results from five independent models

BACKGROUND: Voluntary medical male circumcision (VMMC) has been a recommended HIV prevention strategy in sub-Saharan Africa since 2007, particularly in countries with high HIV prevalence. However, given the scale-up of antiretroviral therapy programmes, it is not clear whether VMMC still represents a cost-effective use of scarce HIV programme resources. METHODS: Using five existing well described HIV mathematical models, we compared continuation of VMMC for 5 years in men aged 15 years and older to no further VMMC in South Africa, Malawi, and Zimbabwe and across a range of setting scenarios in sub-Saharan Africa. Outputs were based on a 50-year time horizon, VMMC cost was assumed to be US$90, and a cost-effectiveness threshold of US$500 was used. FINDINGS: In South Africa and Malawi, the continuation of VMMC for 5 years resulted in cost savings and health benefits (infections and disability-adjusted life-years averted) according to all models. Of the two models modelling Zimbabwe, the continuation of VMMC for 5 years resulted in cost savings and health benefits by one model but was not as cost-effective according to the other model. Continuation of VMMC was cost-effective in 68% of setting scenarios across sub-Saharan Africa. VMMC was more likely to be cost-effective in modelled settings with higher HIV incidence; VMMC was cost-effective in 62% of settings with HIV incidence of less than 0·1 per 100 person-years in men aged 15-49 years, increasing to 95% with HIV incidence greater than 1·0 per 100 person-years. INTERPRETATION: VMMC remains a cost-effective, often cost-saving, prevention intervention in sub-Saharan Africa for at least the next 5 years. FUNDING: Bill & Melinda Gates Foundation for the HIV Modelling Consortium