This manual provides a brief introduction to four classes of software objects developed to help a user create and test interfaces using these objects in the Interface Builder application environment. The Knob, Dial, Alert Light, and Map object classes presented here represent the beginnings of a software library of virtual interface objects designed to support a rapid prototyping environment for advanced interfaces as described in "Rapid Prototyping of Advanced Driver Interface Systems."

Deficit models that predominate neuroHIV research describe adverse, synergistic effects of HIV and older age on neurocognitive impairment, yet many older persons with HIV (PWH) exhibit unimpaired neurocognition. HIV-seronegative studies have identified a subgroup of elders with youthful neurocognition, termed SuperAgers (SA). SA demonstrate stable neurocognitive trajectories and robust neurobiological integrity, consistent with models of cognitive and physiological reserve (CR and PR). However, the construct validity of SuperAging in HIV, including its prevalence, trajectory, and biopsychosocial correlates, is unknown. This three-paper dissertation: 1) established classification criteria for SuperAging in PWH; 2) examined the joint influence of CR and PR on SuperAging; and 3) characterized longitudinal trajectories of SuperAging. All three studies used archival data from older PWH (age range: 50-69) enrolled in studies coordinated by the HIV Neurobehavioral Research Program. Study 1 (N=724, Saloner et al., 2018). Individuals with intact global neurocognition based on normative standards for healthy 25 year-olds were classified as SA (n=124 [17.1%]). SA had similar HIV disease severity but better real-world outcomes (e.g., functional independence) than cognitively normal but non-super (CN) and cognitively impaired (CI) individuals. Study 2 (N=394, Saloner et al., 2022). CR was operationalized as estimated premorbid verbal intelligence (i.e., WRAT4 Reading subtest) and PR was operationalized with a validated disease burden index composed of 39 health variables. Higher PR predicted linear increases in odds of SA (vs. CN and CI) and higher CR predicted a quadratic ‘J-shaped’ change in odds of SA compared to CN (i.e., odds of SA>CN only above 35th percentile of CR). Study 3 (N=184, Saloner et al., 2021). Growth mixture modeling identified a 3-class solution that included Class 1Stable Elite (n=31 [16.8%], a latent class defined by stable and elite global neurocognition across a 5-year longitudinal period. Higher CR, PR, and SA status at baseline increased odds of Class 1Stable Elite membership. Findings support SuperAging in HIV as a construct reflecting neurocognitive resilience that converges with markers of robust biopsychosocial health. Replication of methodology in even older PWH (i.e., 70+ years) may improve characterization of cognitive risk and resilience, particularly among PWH without overt neurocognitive impairment.

Rationale: HIV and aging are associated with an increased risk for HIV-associated neurocognitive disorders (HAND) and Alzheimer’s disease (AD). Cross-sectional research among people with HIV (PWH) has shown that the apolipoprotein e4 (APOE-e4) allele and family history of dementia (FHD+) are independently associated with worse neurocognition. However, these cross-sectional data do not address the potential additive effect of FHD and APOE-e4 on rates of global and domain-specific neurocognitive decline among older PWH.Design: This study utilized longitudinal data from the CNS HIV Antiretroviral Therapy Effects Research programs (N=283 PWH; ages 45-69). Aim 1 used a 2x2 factorial analysis of covariance to model independent and interactive effects of FHD and APOE-e4 status. Aim 2 used linear mixed-effects modeling to examine global- and domain-specific neurocognitive trajectories (average follow-up = 7.0 visits over 5.4 years) in the four FHD/APOE-e4 groups linearly and non-linearly. The exploratory aim examined if demographic, neuropsychiatric, substance use, daily functioning factors, comorbidities, and HIV disease characteristics impact neurocognitive trajectories by FHD and APOE-e4 status, using linear mixed-effects modeling. Results: Cross-sectional analyses revealed lower executive functioning (p = .03) and motor skills (p = .04) T-scores among FHD+. Global T-scores trended towards significance (p = .07), with lower scores among FHD+. Mean differences in motor skills trended towards significance by APOE-e4 status (p = .08), with worse scores among APOE-e4 carriers. Longitudinal analyses revealed significant and trend-level differences in curvilinear trajectories between the FHD-/APOE-e4- and FHD+/APOE-e4+ groups in global performance (p = .01), executive functioning (p = .08), learning (p = .02), delayed recall (p = .07), and motor skills (p = .004). Lastly, demographics, depression, substance use history, cardiovascular conditions, and HIV-disease characteristics significantly predicted poorer neurocognitive outcomes, with worse global- and domain-specific trajectories in the FHD+/APOE-e4+ compared to the FHD-/APOE-e4- group. Conclusions: FHD+ and APOE-e4 jointly heighten risk of cognitive decline among middle-to-older age PWH with compounding medical and psychiatric burdens. Additional research is needed to clarify whether domain-specific differences in curvilinear cognitive trajectories between FHD+/APOE-e4+ and FHD-/APOE-e4- reflect HAND or early-stages of AD, considering there were limited sample sizes in follow-up visits and the possibility that cohorts may have been too young to detect expected neurocognitive decline.  

This thesis presents a new approach to seismic monitoring, the task of detecting seismic events from potentially noisy and cluttered signals recorded across multiple stations. Unlike previous work, which represents seismic signals by a lossy set of discrete detections, we specify a generative probability model of raw seismic waveforms, incorporating a rich representation of the physics underlying the signal generation process, including source mechanisms, wave propagation, and station response. Inference in this model recovers the qualitative behavior of geophysical methods including waveform matching and double-differencing, all as part of a unified Bayesian monitoring system that simultaneously detects and locates events from a network of stations.

Our model of seismic signals combines physically meaningful latent variables such as phase travel times, amplitudes, and signal decay rates, with data-driven models based on historical signals. Detailed waveform structure is represented using Gaussian process models of wavelet coefficients, encoding a general assumption that seismic signals are spatially corre- lated, and allowing us to detect and locate events even from weak signals at a single station. We show that the wavelet coefficients can be marginalized out using message passing applied to a state-space representation of the signal model, allowing for practical inference using a reversible jump Metropolis-Hastings algorithm.

We evaluate our system, SIGVISA (Signal-based Vertically Integrated Seismic Analysis), on a task of monitoring the western United States for a two-week period following the magnitude 6.0 event in Wells, NV in February 2008. During this period, SIGVISA detects between two to three times as many events as detection-based systems, while reducing mean location errors by a factor of four. We provide evidence that SIGVISA detects some events that are missed even by the regional monitoring networks that we use as a ground-truth comparison. A primary driver of monitoring research is the verification of nuclear test ban treaties, which are particularly concerned with detecting events in regions with no nearby historical seismicity. In our experiments, SIGVISA matches or exceeds the detection rates of existing systems for such events, and even detects a number of such events missed by human analysts.

Pre-2018 CSE ID: CS2003-0766

Rationale: Heavy alcohol use is prevalent among people with HIV (PWH) and increases risk for neurocognitive and everyday functioning impairments. Although self-reports of cognitive difficulties are often used clinically to screen for neurocognitive impairment, such retrospective measures are subject to recall error and response bias. Thus, in a sample of PWH who were heavy alcohol drinkers, this study aimed to: 1) evaluate psychometric properties of real-time self-reported cognitive difficulties assessed via smartphone-based ecological momentary assessment (EMA), and 2) examine temporal relationships among EMA self-reported cognitive difficulties, alcohol use, mood, and daily activities.Design: Participants were 23 PWH recruited from existing studies at the HIV Neurobehavioral Research Program who reported current heavy alcohol use. Participants completed two in-person visits separated by a 14-day EMA monitoring period with up to four surveys per day. Objective neurocognition was measured in person by the NIH Toolbox Cognition Battery. Multiple regressions examined whether the proportion of surveys on which participants reported cognitive difficulties related to objective neurocognitive functioning. Mixed effects logistic regressions examined whether EMA-reported alcohol use, depressive symptoms, and cognitively demanding activities related to concurrent EMA-reported cognitive difficulties. Results: Participants were 83% adherent to the EMA surveys on average. Higher proportions of surveys reporting cognitive difficulties were significantly associated with worse objective neurocognitive functioning (p = 0.040); however, EMA-reported real-time cognitive difficulties were not significantly more sensitive or specific in identifying objective neurocognitive impairment compared to an in-person retrospective measure (ps > 0.05). Greater EMA-reported alcohol use (OR = 1.37; p < 0.001) and depressive symptoms (OR = 1.80; p = 0.016) were significantly related to higher likelihood of concurrent cognitive difficulties within persons. EMA-reported engagement in cognitively demanding activities was related to a lower concurrent likelihood of attention difficulties within persons (OR = 0.54; p = 0.032). Conclusions: EMA-reported cognitive difficulties were strongly related to real-time psychological/behavioral factors within persons. Additionally, the association between EMA-reported cognitive difficulties and objective neurocognition suggests that assessing cognitive difficulties in real time via EMA may have some clinical utility to identify individuals from this population who need early intervention and potentially a higher level of care.