Lifespan Research Research Articles

Reliability inference based on inverted exponentiated Rayleigh lifetime distribution under unified hybrid censored scheme

In this study, we investigated the Inverted Exponentiated Rayleigh Distribution (IERD), a significant and efficient continuous lifetime distribution commonly applied in lifespan research. Our focus was on estimating unknown parameters for a two-parameter inverted exponentiated Rayleigh distribution using unified hybrid censored data. We considered both maximum likelihood and Bayesian estimation approaches. Specifically, we employed the Gibbs within Metropolis–Hastings samplers method to develop approximate Bayes estimators utilizing informative and non-informative priors, along with symmetric and asymmetric loss functions. In addition, we utilized Markov chain Monte Carlo (MCMC) samples to derive maximum posterior density credible intervals. Simulation experiments were conducted to assess the efficacy of the proposed methodologies, and actual data analysis was performed to validate the proposed estimators.

Lifespan research in Kenya, Namibia, and South Africa: Cohort profile of the Africa long life study

Most personality science is conducted with samples from wealthy Western countries, home to only 11% of the world’s population. Longitudinal studies have been particularly informative for psychology, but they are virtually absent from the rest of the world. The Africa Long Life Study (ALLS) brings African perspectives to lifespan research in personality and mental health. Large ( N = ∼1000), relatively-representative samples of 18-year-olds were recruited from throughout Namibia, Kenya, and South Africa in 2022. Participants complete two surveys each year. At the time of the fifth wave, we describe here the goals of the ALLS with emphasis on personality psychology, and the contextualized measurement and methodological approaches we have developed, including the process of finding participants again at later waves. Sample characteristics and retention and attrition over the first three waves are reported. Initial lessons learned and reflections on conducting longitudinal research and personality science in Africa are discussed.

A Pilot Study Testing the Novel Use of a Snake Bite Compression Device for Field Hemostasis and Wound Repair in an Animal Model.

A commercially available snake bite device was pilot tested for novel use as a method of hemostasis and wound repair at a noncompressible site in a live swine model. The device is light, is plastic, uses a hook-and-loop strap attachment, and is easily deployed. The device could offer a method for the field repair of an actively bleeding laceration at a noncompressible site in an austere environment. This was an interventional, prospective, controlled study in a large animal model. The study was approved by the Rhode Island Hospital Institutional Review Board (IRB) and the Animal Welfare Committee/Institutional Animal Care and Use Committee and the Lifespan Research Conflict of Interest Committee. Each animal acted as its own control. Blood loss was measured and compared between repairs of standardized incisions with and without the device's application. The lacerations were sutured closed. Two proceduralists alternated tasks of wound repair versus blood collection. Blood loss was measured by using gauze sponges to capture the blood during a 30-second free-bleeding period and during the repair itself. Using a one sample t-test (the expected difference in blood loss between the two incision repair methods = 0 if the null hypothesis were true), we calculated the mean difference in the deltas between the repair methods. The mean delta difference was 3.1 g (SE ± 0.97). The t-test demonstrated that there was a significantly greater blood loss during the standard repair method, t(9) = 3.11, P < 0.01 than during the repair with the device in place (see Fig.2). A statistical power analysis conducted showed that with a sample size of 10 animals, there was sufficient statistical power to detect this significant effect (β = 0.82, α < 0.05, one-tailed). There was statistically significantly less blood loss during the repairs with the device's application. This feasibility experiment demonstrates that a commercially available snakebite device may be useful for hemostasis during laceration repair at anatomic sites not amenable to application of tourniquets or compressive dressings. Strengths of the study include the prospective controlled design, including the use of each animal as its own control; alternating proceduralists to account for any variability in suturing efficiency; and the statistical significance of the results despite the small number of subjects. One weakness is that the time required for each repair was not measured. The device's portability and reusability suggest applicability in austere medical environments. Future studies could include timing the repairs, using a skin stapler or wound adhesive instead of sutures, applying a hemostatic agent before the repair, and sequentially applying the device to wounds longer than the device.

Floating aging mechanism of lithium-ion capacitors: Impedance model and post-mortem analysis

For a new type of energy storage device of lithium-ion capacitor (LIC), it is necessary to evaluate its lifetime for successful market expansion. This paper focuses on explaining the floating aging mechanism under different voltages, combining non-destructive and destructive perspectives. We have accelerated several cells in high temperature climate chambers for overall aging time of more than one year. The floating voltages are set as 2.2, 3 and 3.8 V. The aging mechanism analysis is preliminarily explored using impedance model with both physical meaning and high fitting degree. We perform post-mortem analysis on a brand-new cell and aged ones with different floating voltages to verify the aging mechanism predicted by the impedance model method. We have found that the degradation behavior of high floating voltage is different from that of low floating voltage. The medium voltage region performs well in calendar aging, which is beneficial to the reliability of LIC storage. Some recommendations are given for the non-destructive method, which is helpful for future lifespan research using impedance model.

REVISITING THE ROLE OF PERCEIVED TIME HORIZONS IN SOCIOEMOTIONAL SELECTIVITY THEORY

Abstract This symposium will consider the ways that time horizons may influence motivation and emotional well-being. Socioemotional selectivity theory postulates that goals and motivation shift from ones about learning and exploration to ones about emotional meaning as time horizons grow constrained as people age. This theory maintains that a focus on emotional goals explains why older adults tend to show better emotional well-being compared to younger adults. Many studies use the Future Time Perspective scale developed by Carstensen and Lang (1996) to measure perceived time left in life. However, several studies find more limited future time perspective does not contribute to better emotional well-being nor more positivity bias in cognitive processing and in some cases predicts poorer emotional well-being. The first presentation will focus on the future time perspective scale and its underlying structure. The second presentation will discuss the association between future time perspective and psychosocial well-being during the COVID-19 pandemic. The third presentation will review different measures of time perception and examine the relationship between future time perspective on age-related positivity effect. The last presentation will introduce a new concept and measurement, time savoring. Laura Carstensen will synthesize findings and offer insights regarding future life-span research on motivation and well-being.

Spelling out some unaddressed conceptual and methodological challenges in empirical lifespan research

The importance of taking a lifespan approach to describe and understand human development has long been acknowledged (e.g., Baltes, 1987). Nevertheless, theoretical or empirical research that actually encompasses the entire lifespan, that is, from early childhood to old age, is rare. This is not surprising given the challenges such an approach entails. Many of these challenges (e.g., establishing measurement invariance between age groups) have been addressed in the previous literature, but others have not yet been sufficiently considered. The main purpose of this article is to present several examples of such largely unaddressed conceptual and methodological challenges and reflect upon possible ways to address them. We discuss the usefulness of a lifespan approach and the generalization of the challenges to other research comparing different groups, such as gender, culture, or species.

The utility of hierarchical models of psychopathology in genetics and biomarker research.

The utility of hierarchical models of psychopathology in genetics and biomarker research.

Predictors of Biological Age: The Implications for Wellness and Aging Research.

As healthspan and lifespan research breakthroughs have become more commonplace, the need for valid, practical markers of biological age is becoming increasingly paramount. The accessibility and affordability of biological age predictors that can reveal information about mortality and morbidity risk, as well as remaining years of life, has profound clinical and research implications. In this review, we examine 5 groups of aging biomarkers capable of providing accurate biological age estimations. The unique capabilities of these biomarkers have far reaching implications for the testing of both pharmaceutical and non-pharmaceutical interventions designed to slow or reverse biological aging. Additionally, the enhanced validity and availability of these tools may have increasingly relevant clinical value. The authors of this review explore those implications, with an emphasis on lifestyle modification research, and provide an overview of the current evidence regarding 5 biological age predictor categories: Telomere length, composite biomarkers, DNA methylation “epigenetic clocks,” transcriptional predictors of biological age, and functional age predictors.

A recipe for accurate estimation of lifespan brain trajectories, distinguishing longitudinal and cohort effects

We address the problem of estimating how different parts of the brain develop and change throughout the lifespan, and how these trajectories are affected by genetic and environmental factors. Estimation of these lifespan trajectories is statistically challenging, since their shapes are typically highly nonlinear, and although true change can only be quantified by longitudinal examinations, as follow-up intervals in neuroimaging studies typically cover less than 10% of the lifespan, use of cross-sectional information is necessary. Linear mixed models (LMMs) and structural equation models (SEMs) commonly used in longitudinal analysis rely on assumptions which are typically not met with lifespan data, in particular when the data consist of observations combined from multiple studies. While LMMs require a priori specification of a polynomial functional form, SEMs do not easily handle data with unstructured time intervals between measurements. Generalized additive mixed models (GAMMs) offer an attractive alternative, and in this paper we propose various ways of formulating GAMMs for estimation of lifespan trajectories of 12 brain regions, using a large longitudinal dataset and realistic simulation experiments. We show that GAMMs are able to more accurately fit lifespan trajectories, distinguish longitudinal and cross-sectional effects, and estimate effects of genetic and environmental exposures. Finally, we discuss and contrast questions related to lifespan research which strictly require repeated measures data and questions which can be answered with a single measurement per participant, and in the latter case, which simplifying assumptions that need to be made. The examples are accompanied with R code, providing a tutorial for researchers interested in using GAMMs.

Uncertainty in Aging and Lifespan Research: Covid-19 as Catalyst for Addressing the Elephant in the Room.

Uncertainty is at the center of debates on how to best cope with the Covid-19 pandemic. In our exploration of the role of uncertainty in current aging and lifespan research, we build on an uncertainty regulation framework that includes both reduction and creation of uncertainty as viable self-regulatory processes. In particular, we propose that future time perspective, a key component in models of successful aging, should be reconceptualized in terms of uncertainty regulation. We argue that by proactively regulating the amount of uncertainty one is exposed to, individuals’ future time perspective can be altered. We show how extant research might be (re)interpreted based on these considerations and suggest directions for future research, challenging a number of implicit assumptions about how age and uncertainty are interlinked. We close with some practical implications for individuals and organizations for managing the Covid-19 crisis.

The Mobile Health Multiple Lifestyle Behavior Interventions Across the Lifespan (MoBILE) Research Program: Protocol for Development, Evaluation, and Implementation

BackgroundClustering of multiple lifestyle risk behaviors has been associated with a greater risk of noncommunicable diseases and mortality than one lifestyle risk behavior or no lifestyle risk behaviors. The National Board of Health and Welfare in Sweden reported in 2018 that it is important to provide additional support to individuals with multiple lifestyle risk behaviors, as risks from these behaviors are multiplicative rather than additive. However, the same report emphasized that there is a lack of knowledge regarding interventions that support changes to unhealthy lifestyle behaviors.ObjectiveThe MoBILE (Mobile health Multiple lifestyle Behavior Interventions across the LifEspan) research program has brought together two Swedish research groups supported by international collaborators. Through this collaboration, we aim to design and evaluate a number of novel and tailored mobile health (mHealth) multiple lifestyle behavior interventions across the life span of different health care populations. In addition, the MoBILE research program will extend ongoing research to include mHealth interventions for migrant pregnant women and children.MethodsEach project within the MoBILE program will focus on a specific group: pregnant women, preschool children, high school and university students, and adults in primary and clinical care. All the projects will follow the same 4 phases: requirements, development, evaluation, and implementation. During the requirements phase, implementers and end users will aid the design of content and functionality of the interventions. In the development phase, findings from the first phase will be synthesized with expert domain knowledge and theoretical constructs to create interventions tailored to the target groups. The third phase, evaluation, will comprise randomized controlled trials conducted to estimate the effects of the interventions on multiple lifestyle risk behaviors (eg, alcohol, nutrition, physical activity, and smoking). The final phase will investigate how the interventions, if found effective, can be disseminated into different health care contexts.ResultsThe research program commenced in 2019, and the first results will be available in 2020. Projects involving pregnant women, preschool children, and high school and university students will be completed in the first 3 years, with the remaining projects being planned for the program’s final 3 years.ConclusionsThe development of evidence-based digital tools is complex, as they should be guided by theoretical frameworks, and requires large interdisciplinary teams with competence in technology, behavioral science, and lifestyle-specific areas. Individual researchers or smaller research groups developing their own tools is not the way forward, as it means reinventing the wheel over and over again. The MoBILE research program therefore aims to join forces and learn from the past 10 years of mHealth research to maximize scientific outcomes, as well as the use of financial resources to expand the growing body of evidence for mHealth lifestyle behavior interventions.International Registered Report Identifier (IRRID)PRR1-10.2196/14894

The role of cognition for speech-in-noise perception: Considering individual listening strategies related to aging and hearing loss

Listening to speech in a noisy background is difficult for everyone. While such listening has historically been considered mainly in the context of auditory processing, the role of cognition has attracted considerable interest in recent years. This has been particularly true in the context of life-span research and the comparison of younger and older listeners. This article will discuss three factors that are important to consider when investigating the nature of cognitive involvement in speech-in-noise (SiN) perception: (1) the listening situation, (2) listener variables, and (3) the role of hearing aids. I argue that a similar level of intelligibility can be achieved with the support of very different skills, or listening strategies, depending on the listening situation and listener. Age as a variable is particularly instructive for this type of research as it is accompanied by auditory as well as cognitive changes. As age-related changes are not uniform, using aging as a tool for the investigation can increase the opportunity to see individual differences in contributing processes and resulting compensation strategies. In addition to highlighting different interaction effects between hearing and cognition, I will argue that our conceptual understanding of the underlying processes can only be furthered if the selection of cognitive tests and experimental procedures in SiN studies follows accepted cognitive models, so that understanding can advance on a conceptual level without reliance on a particular test. Ultimately, a better understanding of the various listening strategies available to listeners, and the conditions under which they are used, may have theoretical as well as practical implications. Theoretically, it may help us better understand phenomena such as listening effort. Practically, it may guide us toward more effective diagnosis and intervention for listening difficulties in everyday life.

Clinicians' perspectives on diagnosing polycystic ovary syndrome in Australia: a qualitative study.

What are clinicians' views about the diagnosis of polycystic ovary syndrome (PCOS), and how do they handle any complexities and uncertainties in practice? Clinicians have to navigate many areas of complexity and uncertainty regarding the diagnosis of PCOS, related to the diagnostic criteria, limitations in current evidence and misconceptions surrounding diagnosis, and expressed concern about the risk and consequences of both under- and overdiagnosis. PCOS is a complex, heterogeneous condition with many areas of uncertainty, raising concerns about both underdiagnosis and overdiagnosis. Quantitative studies with clinicians have found considerable variation in diagnostic criteria used and care provided, as well as a lack of awareness around the breadth of PCOS features and poor uptake of recommended screening for metabolic complications. Clinicians' views about the uncertainties and complexities of diagnosing PCOS have not been explored. Semi-structured telephone interviews were conducted with clinicians from September 2017 to July 2018 to explore their perceptions about the diagnosis of PCOS, including how they handle any complexities and uncertainties in practice. A group of 36 clinicians (15 general practitioners, 10 gynaecologists and 11 endocrinologists) currently practicing in Australia, were recruited through advertising via professional organisations, contacting a random sample of endocrine and gynaecology teams across Australia and snowballing. Transcribed audio-recordings were analysed thematically using Framework analysis. Clinicians expressed a range of uncertainties and complexities regarding the diagnosis of PCOS, which were organised into three areas: (i) establishing diagnosis (e.g. lack of standardisation regarding diagnostic cut-offs, risk of misdiagnosis), (ii) factors influencing the diagnostic process (e.g. awareness of limitations in evidence and consideration of the benefits and harms) and (iii) strategies for handling challenges and uncertainties (e.g. using caution and communication of uncertainties). Clinicians also varied in their concerns regarding under- and overdiagnosis. Overall, most felt the diagnosis was beneficial for women provided that it was the correct diagnosis and time was taken to assess patient expectations and dispel misconceptions, particularly concerning fertility. There is possible selection bias, as clinicians who are more knowledgeable about PCOS may have been more likely to participate. Clinicians' views may also differ in other countries. These findings underscore the vital need to first consider PCOS a diagnosis of exclusion and use caution before giving a diagnosis in order to reduce misdiagnosis, as suggested by clinicians in our study. Until there is greater standardisation of diagnostic criteria, more transparent conversations with women may help them understand the uncertainties surrounding the criteria and limitations in the evidence. Additionally, clinicians emphasised the importance of education and reassurance to minimise the potential harmful impact of the diagnosis and improve patient-centred outcomes. The study was funded by the University of Sydney Lifespan Research Network and an NHMRC Program Grant (APP1113532). T.C. is supported by an Australian Government Research Training Program (RTP) Scholarship and a Sydney Medical School Foundation Scholarship, from the The University of Sydney, Australia. B.W.M. reports consultancy for ObsEva, Merck, Merck KGaA and Guerbet. No further competing interests exist. N/A.

Assessing prospective memory in children using the Memory for Intentions Screening Test for Youth (MISTY)

Objective Prospective memory (PM) is defined as the ability to remember to complete an intention in the future. The first aim of this study was to address the need for clinically useful measures of PM in children, by assessing the psychometric properties of a new measure of PM in children and adolescents, the Memory for Intentions Screening Test for Youth (MISTY). The second aim was to assess the relationship between prospective memory and age, particularly the relationships between age and the impact of different PM task demands. The third aim was to examine children’s performance on different aspects of PM, such as time-based versus event-based cues. Method One-hundred twenty-four children between the ages of 4 and 15 were given the MISTY. Results Analyses revealed good internal consistency among the eight individual MISTY trials and among the six MISTY subscales which included two different cue types (event-based and time-based), two different time delays (2 minutes and 10 minutes), and two different response types (action and verbal). Results also revealed good split-half and inter-rater reliability. Findings highlighted significant correlations between age and the MISTY total score and all subscales, consistent with PM lifespan research. On the MISTY, children overall performed better on event-based cues than on time-based cues, and on shorter time delays than longer ones; there was no effect of response type (i.e. action vs. verbal response). Conclusions The MISTY is a promising instrument with sound psychometric properties that could be useful in both clinical and research settings. Additionally, this study highlights the age-related process of PM development in children.

Grammaticalization and the linguistic individual: new avenues in lifespan research

AbstractThis paper reviews theoretical and methodological advances and issues in lifespan research and discusses how the issues at stake are addressed in an ongoing research project. Summarizing the state of the art, we conclude that next to nothing is known about lifespan changes affecting syntactic or grammaticalizing constructions that goes beyond exploratory or anecdotal evidence. TheMind-Bending Grammarsproject, which examines the adaptive powers of adult cognition and constraints on these powers, aspires to make headway in this area. In this paper, we introduce some of the major goals of the project and present a new large-scale longitudinal corpus of 50 adults that was established to study grammatical change across the lifespan. Particular attention is paid to the constraints on the adoption of novel grammatical patterns in the aging mind. Takingbe going toas a case study, we present evidence that (highly educated) healthy monolingual speakers continue to participate in grammatical innovations across the lifespan.

On the use of growth models to study normal cognitive aging

Growth models (GM) of the mixed-effects and latent curve varieties have become popular methodological tools in lifespan research. One of the major advantages of GM is their flexibility in studying individual differences in change. We scrutinized the change functions of GM used in five years of publications on cognitive aging. Of the 162 publications that we identified, 88% test linear or quadratic polynomials, and fewer than 5% apply functions that are nonlinear in their parameters, such as exponential decline. This apparent bias in favor of polynomial decomposition calls for exploring what conclusions about individual differences in change are likely to be drawn if one applies linear or quadratic GMs to data simulated under a conceptually and empirically plausible model of exponential cognitive decline from adulthood to old age. Hence, we set up a simulation that manipulated the rate of exponential decline, measurement reliability, number of occasions, interval width, and sample size. True rate of decline and interval width influenced results strongly, number of occasions and measurement reliability exerted a moderate effect, and the effects of sample size appeared relatively minor. Critically, our results show that fit statistics generally do not differentiate misspecified linear or quadratic models from the true exponential model. Moreover, power to detect variance in change for the linear and quadratic GMs is low, and estimates of individual differences in level and change can be highly biased by model misspecification. We encourage researchers to also consider plausible nonlinear change functions when studying behavioral development across the lifespan.

The benefits and harms of receiving a polycystic ovary syndrome diagnosis: a qualitative study of women's experiences.

STUDY QUESTIONWhat are the benefits and harms of receiving a polycystic ovary syndrome (PCOS) diagnosis in a community sample of women, including impact on psychosocial wellbeing, lifestyle choices and behaviour?SUMMARY ANSWERAlthough some women benefit considerably from the diagnosis, such as through increased awareness and reassurance, women with minimal symptoms may experience more harm than benefit, including long-lasting anxiety and altered life plans.WHAT IS KNOWN ALREADYDisease labels can validate symptoms and play a vital role in understanding and coping with illness; however, they can also cause harm by evoking illness schemas about severity and permanence. Regarding PCOS, the diagnostic criteria have expanded over time to include women with milder phenotypes (such as those without signs of androgen excess). This has occurred despite limited investigation of the benefits and harms of the diagnosis and has increased the number of women diagnosed.STUDY DESIGN, SIZE, DURATIONSemi-structured interviews were conducted face-to-face or by telephone with 26 participants from April–July 2018 to explore women’s experiences with the diagnosis, including the benefits and harms of receiving the diagnosis and the impact on their life.PARTICIPANTS/MATERIALS, SETTING, METHODSIn total, 26 women in the community self-reporting a diagnosis of PCOS (reporting mild to severe symptoms) made by a medical doctor, aged 18–45 years and living in Australia were recruited through social media. Data were analysed thematically using Framework analysis.MAIN RESULTS AND THE ROLE OF CHANCEThe study identified a range of both positive and negative effects of a PCOS diagnosis in the immediate, short and long-term, which were influenced by symptom severity, expectations and experience. For women with previously unexplained and bothersome symptoms, it was a relief to receive a diagnosis, and this resulted in an increased understanding about the importance of a healthy lifestyle. By contrast, women with milder symptoms often reported feeling shocked and overwhelmed by the diagnosis, consequently experiencing anxiety about the associated long-term risks. The majority of women, regardless of symptom severity, experienced prolonged worry and anxiety about infertility, resulting for some in risk taking with contraception, unintended pregnancies, pressure to conceive early or altered life plans. With time, many women developed positive coping strategies and perceived the diagnosis to be valuable, including those who felt they had experienced minimal benefit or even harm.LIMITATIONS, REASONS FOR CAUTIONPCOS diagnosis was self-reported and the sample was highly educated.WIDER IMPLICATIONS OF THE FINDINGSFear of infertility was salient for many women, underscoring the need for accurate information, counselling and reassurance of fertility potential. Given the risk of significant consequences, health professionals should use a tailored approach to PCOS diagnosis to increase the benefits of appropriate and timely diagnosis for women affected by significant symptoms, while reducing the harms of unnecessarily labelling healthy women for whom the benefits of a diagnosis are small.STUDY FUNDING/COMPETING INTEREST(S)The study was funded by the University of Sydney Lifespan Research Network and an NHMRC Program Grant (APP1113532). B.W.M. reports consultancy for ObsEva, Merck, Merck KGaA and Guerbet. No further competing interests exist.TRIAL REGISTRATION NUMBERN/A

Predicting real-world behaviour: Cognition-emotion links across adulthood and everyday functioning at work

ABSTRACTInspired by the discovery of positive age trends in emotional well-being across adulthood, lifespan researchers have uncovered fascinating age differences in cognition–emotion interactions in healthy adult samples, for example in emotion processing, memory, reactivity, perception, and regulation. Taking stock of this body of research, I identify four trends and five remaining gaps in our understanding of emotional functioning in adulthood. In particular, I suggest that the field should pay stronger attention to the prediction of real-world behaviour. Using the sample case of work functioning, I outline gaps in current knowledge, including the lack of data on middle-aged adults, the neglect of relevant cognitive-emotional mechanisms, and the unclear role of life experience. Filling these gaps will enable progress in research on emotional aging in and beyond the work setting and enhance its practical utility for individuals, organisations, and society.

Advantages and Limitations of Silkworm as an Invertebrate Model in Aging and Lifespan Research

Advantages and Limitations of Silkworm as an Invertebrate Model in Aging and Lifespan Research

Opportunities for life course research through the integration of data across Clinical and Translational Research Institutes.

Early life exposures affect health and disease across the life course and potentially across multiple generations. The Clinical and Translational Research Institutes (CTSIs) offer an opportunity to utilize and link existing databases to conduct lifespan research. A survey with Lifespan Domain Taskforce expert input was created and distributed to lead lifespan researchers at each of the 64 CTSIs. The survey requested information regarding institutional databases related to early life exposure, child-maternal health, or lifespan research. Of 64 CTSI, 88% provided information on a total of 130 databases. Approximately 59% (n=76/130) had an associated biorepository. Longitudinal data were available for 72% (n=93/130) of reported databases. Many of the biorepositories (n=44/76; 68%) have standard operating procedures that can be shared with other researchers. The majority of CTSI databases and biorepositories focusing on child-maternal health and lifespan research could be leveraged for lifespan research, increased generalizability and enhanced multi-institutional research in the United States.