University of Michigan
  • Ann Arbor, United States
Recent publications
A large-eddy simulation framework has been coupled with controller modules to systematically investigate the impacts of collective (CPC) and individual (IPC) pitch control strategies on utility-scale wind turbine energy production and fatigue loads. Wind turbine components were parameterized using an actuator surface model to simulate the rotor blades and the turbine nacelle. The baseline CPC and IPC algorithms, consisting of single-input single-output proportional–integral controllers and two integral controllers, respectively, were incorporated into the numerical framework. A series of simulations were carried out to investigate the relative performance of the two controllers under various turbulent inflow conditions, spanning hub-height velocities of 7 to 14 m/s. The numerical simulation results of this study showed that, in comparison to the CPC, the IPC controller could successfully reduce the damage equivalent loads of utility-scale turbines at regions 2 and 3 of turbine operation by about 3% and 40%, respectively, without any penalty on the power production of the turbine. It was also shown that, despite its minor impact on the turbulence kinetic energy of the wake, the IPC controller did not influence the recovery of the turbine wake.
Determining the maximum cut of large graphs may require impractically long time, necessitating approximate algorithms and/or specialized computing platforms. A heuristic by Burer, Monteiro and Zhang for max-cut has not only been shown to be advantageous in many respects, but is also applicable to other NP-complete problems. From the perspective of accelerated computing, the heuristic's implementational challenge lies in its gradient-descent dynamics, which could be reduced to several sinusoidal kernel operations applied to each edge of the graph. We had previously established the theoretical underpinnings of a relaxed dynamical heuristic for max-cut similar to the one proposed by Burer et al. but suited for accelerated computing on custom analog CMOS. In this work, we present the first fully custom analog integrated circuit implementing the dynamics of our heuristic on 130-nm CMOS technology. In an era of increasing specificity of computing machines, our algorithm-circuit co-design, originally for max-cut, introduces a versatile approach applicable to a diverse set of practical large-scale NP-complete problems.
This keyword essay establishes the significance of international law for the study of Victorian globalization. The history of international law has not really been registered yet by scholars in Victorian studies, but we might obtain a number of dividends by remedying that deficit.
This essay argues that “experience” is an essential keyword for Victorian studies. The concept spiked in interest in the latter half of the nineteenth century. Causes for this spike include the division of humanistic knowledge into the modern disciplines, and the pressure that idealist philosophy put on British empiricist thought. Shadworth Hodgson's 1898 The Metaphysic of Experience is featured both as a text exemplifying the paradoxes of Victorian experience-talk and as an invitation to further study.
How much time has passed since the publication of VLC’ s Keywords issue five years ago? This is not a trick question. Students of nineteenth-century British literature and culture are primed to see five years as a long time (“with the length of five long summers”), and events at both national and global scales have encouraged a widespread sense that 2018 is located less in the recent past than on the far side of a divide—in the Before Times. On the other hand, the long view encouraged by a scholarly focus on a period that ended over a century ago may see little or no meaningful time as having passed between 2018 and 2023. Moreover, on a more quotidian level, the very pace of scholarship—the amount of time it typically takes to conceive, research, write, and publish work, even for those without a Casaubonian bone in their bodies—can make five years seem like no time at all (“five summers that flew by,” as Wordsworth might have put it had he been on an academic calendar).
Talk of meaning and meaningfulness, ubiquitous today, only emerges in the nineteenth century. This emergence remains to be explained and calls into question accounts of modernity that treat “meaning” as a stable, timeless concept.
Most readers of this journal will not have seen this word before. How, then, can it claim a spot in this Keyword issue of Victorian Literature and Culture ? How can a non-English word—not even a loan word in English—become an English keyword? Ta‘āruf’ s presence here can be justified through the now less-familiar definition of the term “keyword” itself: “a word that serves as the key to a cipher or code.” A loan word from Arabic, in Persian ta‘āruf means pleasantries, greetings, and hospitality, on one hand, and gift-giving on the other. Conjoining a sense of linguistic surplus and gift-exchange, ta‘āruf , I argue, serves as a key to decipher some complications at the intersection of economic and linguistic exchange in Victorian literature and culture. As such, it also establishes that “Victorian” culture emerges out of transnational bargains of exchange and translation.
Background Some hormonally active cancers have low survival rates, but a large proportion of their incidence remains unexplained. Endocrine disrupting chemicals may affect hormone pathways in the pathology of these cancers. Objective To evaluate cross-sectional associations between per- and polyfluoroalkyl substances (PFAS), phenols, and parabens and self-reported previous cancer diagnoses in the National Health and Nutrition Examination Survey (NHANES). Methods We extracted concentrations of 7 PFAS and 12 phenols/parabens and self-reported diagnoses of melanoma and cancers of the thyroid, breast, ovary, uterus, and prostate in men and women (≥20 years). Associations between previous cancer diagnoses and an interquartile range increase in exposure biomarkers were evaluated using logistic regression models adjusted for key covariates. We conceptualized race as social construct proxy of structural social factors and examined associations in non-Hispanic Black, Mexican American, and other Hispanic participants separately compared to White participants. Results Previous melanoma in women was associated with higher PFDE (OR:2.07, 95% CI: 1.25, 3.43), PFNA (OR:1.72, 95% CI: 1.09, 2.73), PFUA (OR:1.76, 95% CI: 1.07, 2.89), BP3 (OR: 1.81, 95% CI: 1.10, 2.96), DCP25 (OR: 2.41, 95% CI: 1.22, 4.76), and DCP24 (OR: 1.85, 95% CI: 1.05, 3.26). Previous ovarian cancer was associated with higher DCP25 (OR: 2.80, 95% CI: 1.08, 7.27), BPA (OR: 1.93, 95% CI: 1.11, 3.35) and BP3 (OR: 1.76, 95% CI: 1.00, 3.09). Previous uterine cancer was associated with increased PFNA (OR: 1.55, 95% CI: 1.03, 2.34), while higher ethyl paraben was inversely associated (OR: 0.31, 95% CI: 0.12, 0.85). Various PFAS were associated with previous ovarian and uterine cancers in White women, while MPAH or BPF was associated with previous breast cancer among non-White women. Impact Statement Biomarkers across all exposure categories (phenols, parabens, and per- and poly- fluoroalkyl substances) were cross-sectionally associated with increased odds of previous melanoma diagnoses in women, and increased odds of previous ovarian cancer was associated with several phenols and parabens. Some associations differed by racial group, which is particularly impactful given the established racial disparities in distributions of exposure to these chemicals. This is the first epidemiological study to investigate exposure to phenols in relation to previous cancer diagnoses, and the first NHANES study to explore racial/ethnic disparities in associations between environmental phenol, paraben, and PFAS exposures and historical cancer diagnosis.
To establish requirements for normal databases for quantitative rubidium-82 (82Rb) PET MPI analysis with contemporary 3D PET/CT technology and reconstruction methods for maximizing diagnostic accuracy of total perfusion deficit (TPD), a combined metric of defect extent and severity, versus invasive coronary angiography. In total, 1571 patients with 82Rb PET/CT MPI on a 3D scanner and stress static images reconstructed with and without time-of-flight (TOF) modeling were identified. An additional eighty low pre-test probability of disease (PTP) patients reported as normal were used to form separate sex-stratified and sex-independent iterative and TOF normal databases. 3D normal databases were applied to matched patient reconstructions to quantify TPD. Per-patient and per-vessel performance of 3D versus 2D PET normal databases was assessed with receiver operator characteristic curve analysis. Diagnostic accuracy was evaluated at optimal thresholds established from PTP patients. Results were compared against logistic regression modeling of TPD adjusted for clinical variables, and standard clinical interpretation. TPD diagnostic accuracy was significantly higher using 3D PET normal databases (per-patient: 80.1% for 3D databases, versus 74.9% and 77.7% for 2D database applied to iterative and TOF images respectively, p < 0.05). Differences in male and female normal distributions for 3D attenuation-corrected reconstructions were not clinically meaningful; therefore, sex-independent databases were used. Logistic regression modeling including TPD demonstrated improved performance over clinical reads. Normal databases tailored to 3D PET images provide significantly improved diagnostic accuracy for PET MPI evaluation with automated quantitative TPD. Clinical application of these techniques should be considered to support accurate image interpretation.
Background Preconception care is not widespread in Japan and there is a pressing need to improve the practice. The present study assessed the knowledge and behavior of preconception care among women to seek effective intervention. Our research questions were: 1) How much do women know about preconception care? 2) How much are they practicing preconception care and what are the information sources of their behavior? 3) Do the women's preconception care behavior associated with accurate knowledge? Methods The research was conducted in a rural town in central Japan. Using an exploratory sequential mixed methods design, we undertook interviews, developed a survey based on the qualitative results, and then conducted a survey. The interviews explored how preconception care was perceived and practiced in women of childbearing age. The survey was designed to investigate the knowledge of preconception care among women with and without pregnancy experience, their practice behavior of preconception care, and whether the behavior is associated with knowledge. Results The participants were 13 for the interview and 232 for the survey. They had limited access to preconception care recommendations and advice for specific actions was given by obstetricians and gynecologists after pregnancy. There was a large gap in knowledge about preconception care between parous and nulliparous women, especially about the need for folic acid supplementation. Practices that were manageable in their daily lives, such as cessation of smoking and alcohol, diet, and weight management, were considered common sense. In contrast, recommended practices that require medical attention, such as screening for sexually transmitted diseases and cervical cancer, tended to be less accurately known and practiced. Participants' sources of information about preconception care were the Internet, family and friends and mass media. Conclusion In rural Japan, women of childbearing age lack knowledge about preconception care, especially before their first pregnancy. Primary care providers should try outreach to schools and women’s groups in the community, promote information sharing among family and close friends, and utilize information technology to enhance the knowledge and practice of preconception care.
Background A majority of women with multiple sclerosis (MS) are diagnosed prior to menopause, yet their experiences during this transition are not well characterized. Objectives To explore associations between mental health, sleep, and other quality of life metrics, and vasomotor symptoms (VMSs) in ambulatory, menopausal women with MS. Methods A secondary analysis was performed of baseline data from two trials enrolling ambulatory peri/postmenopausal women with MS: NCT02710214 ( N = 24, bothersome VMS) and NCT04002934 (ongoing, N = 35, myelin repair). Measures analyzed were 36-Item Short-Form Survey (SF-36) (primary scale: general mental health), subjective sleep quality (Pittsburg Sleep Quality Index), VMS (daily diary, interference), mood (Center for Epidemiologist Studies—Depression Scale (CES-D)), walking impairment (timed 25-foot walk (T25FW)), and global disability (Expanded Disability Status Scale (EDSS)). Results Participants’ characteristics ( N = 59) were: mean age 51.8 years ( SD = 3.4), mean disease duration 11.3 years ( SD = 7.6), median EDSS 3.0 (IQR = 2.0–4.0). Mental health was associated with better sleep quality (rho = −0.41, p = 0.019) and better mood (rho = −0.75, p < 0.001), but not with EDSS or T25FW (rho < 0.20, p > 0.10). Worse sleep quality also correlated with more frequent VMS (rho = 0.41, p = 0.02) and VMS interference (rho = 0.59, p < 0.001). Conclusions Findings suggest that optimizing sleep quality, mood, and hot flash quantity/interference could substantially improve mental health in menopausal women with MS—and highlight an important care gap in this population.
Identifying the physical process(s) responsible for heating the solar corona and thus driving the solar wind is perhaps the most important open question in heliophysics. This is a primary goal of the Parker Solar Probe (PSP) Mission. Various heating mechanisms have been suggested but one that is gaining increasing credence is associated with the dissipation of low frequency magnetohyrodynamic (MHD) turbulence. We review two current turbulence models, describe the modeling that has been done, and relate Parker Solar Probe (PSP) observations to the basic predictions of both models. PSP entered a region of sub-Alfvénic solar wind during encounter 8 and we review the low-frequency turbulence properties in this novel region. The observed spectra are well fitted using a spectral theory for nearly incompressible magnetohydrodynamics.
Sporotrichosis is a subacute to chronic fungal infection of skin and subcutaneous tissues. The causative agent, Sporothrix schenckii, is a dimorphic fungus that exists as a mold in the environment and as a yeast in tissues. S. schenckii is not a single species, but rather a complex of at least 6 phylogenetically different organisms. In the environment, S. schenckii is found in sphagnum moss, decaying wood, vegetation, hay, and soil. Infection occurs when a person is exposed to an environmental source, and the organism is inoculated through the skin. A large continuing outbreak in Rio de Janeiro is associated with zoonotic transmission from infected cats. The most common manifestation of sporotrichosis is lymphocutaneous or localized cutaneous infection. Pulmonary sporotrichosis mimics reactivation tuberculosis and occurs most often in those who have chronic obstructive pulmonary disease. Osteoarticular sporotrichosis is uncommon and is found most often in middle-aged men. Disseminated and meningeal sporotrichosis are very uncommon; almost all patients have cellular immune deficiencies, and most cases are in persons with AIDS. Most patients who have sporotrichosis can be successfully treated with oral itraconazole although saturated solution of potassium iodide (SSKI) is still used in some countries. Those patients who have disseminated infection, meningitis, or severe pulmonary involvement should be treated initially with an intravenous amphotericin B formulation before transitioning to itraconazole.
We demonstrate that many Naturalness tests of particle theories discussed in the literature can be reformulated as straightforward algorithmic finetuning assessments in the matching of Wilsonian effective theories above and below particle mass thresholds. Implications of this EFT formulation of Wilsonian Naturalness are discussed for several theories, including the Standard Model, heavy singlet scalar theory, supersymmetry, Grand Unified Theories, twin Higgs theories, and theories of extra dimensions. We argue that the Wilsonian Naturalness algorithm presented here constitutes an unambiguous, a priori, and meaningful test that the Standard Model passes and which “the next good theory” of particle physics is very likely to pass.
With new direct dates from rock paintings comes an unprecedented opportunity to relate excavated archaeological data to the parietal record in southern Africa’s Maloti-Drakensberg Mountains. Anchoring dated art to recovered palaeoenvironmental, faunal and technological data enables the incorporation into socioecological models of ideational inferences, affording insights into how hunter- gatherers perceived their mountain habitats. Of particular interest is the late Holocene Neoglacial (∼3.5–2 kcal BP), during which skilled paintings were being made just as the region experienced dynamic changes owing in part to climate change. Responses of local foragers are evident across a range of cultural spheres, including dramatic subsistence transformations. With the Maloti- Drakensberg’s well-known “traditional corpus” of fine-line art now known to extend back to at least 3 kcal BP, here we explore how such changes may have precipitated – and in turn been influenced by – ontological shifts in relation to the food quest. As desirable game declined and hunting windows narrowed, we suggest that Neoglacial foragers sought to manage scheduling and social conflicts through enhanced spiritual negotiation with non-human entities in the landscape. Facilitated by the supernaturally charged nature of their elevated cosmos, this intensified spiritual labour may have found material expression in an elaborate new style of painting.
Introduction Alcohol cessation improves mortality in alcohol-associated liver disease (ALD), but few ALD patients will engage in treatment. We aimed to demonstrate the feasibility and acceptability of a mobile health intervention to increase alcohol use disorder (AUD) treatment among ALD patients. Methods We conducted a pilot randomized controlled trial (September 2020 to June 2022) at a single tertiary care center in adults with any stage of ALD, past 6-month drinking, and no past-month AUD treatment. Sixty participants were randomized 1:1 to a mobile health application designed to increase AUD treatment engagement through preference elicitation and matching to treatment and misconception correction. Controls received enhanced usual care. The primary outcomes were feasibility (recruitment and retention rates) and acceptability. Exploratory outcomes were AUD treatment engagement and alcohol use, measured by Timeline Followback. Outcomes were measured at 3 and 6 months. Results Baseline characteristics were balanced. The recruitment rate was 46%. Retention was 65% at 6 months. The intervention was highly acceptable to participants (91% were mostly/very satisfied; 95% felt that the intervention matched them well to AUD treatment). Secondary outcomes showed increased AUD treatment at 6 months in the intervention group (intent-to-treat: 27.3% vs. 13.3%, OR 2.3, 95% CI, 0.61–8.76). There was a trend toward a 1-level or greater reduction in World Health Organization (WHO) drinking risk levels in the intervention group (OR 2.25, 95% CI, 0.51–9.97). Conclusions A mobile health intervention for AUD treatment engagement was highly feasible, acceptable, and produced promising early outcomes, with improved AUD treatment engagement and alcohol reduction in ALD patients.
Monitoring sleep and activity through wearable devices such as wrist-worn actigraphs has the potential for long-term measurement in the individual’s own environment. Long periods of data collection require a complex approach, including standardized pre-processing and data trimming, and robust algorithms to address non-wear and missing data. In this study, we used a data-driven approach to quality control, pre-processing and analysis of longitudinal actigraphy data collected over the course of 1 year in a sample of 95 participants. We implemented a data processing pipeline using open-source packages for longitudinal data thereby providing a framework for treating missing data patterns, non-wear scoring, sleep/wake scoring, and conducted a sensitivity analysis to demonstrate the impact of non-wear and missing data on the relationship between sleep variables and depressive symptoms. Compliance with actigraph wear decreased over time, with missing data proportion increasing from a mean of 4.8% in the first week to 23.6% at the end of the 12 months of data collection. Sensitivity analyses demonstrated the importance of defining a pre-processing threshold, as it substantially impacts the predictive value of variables on sleep-related outcomes. We developed a novel non-wear algorithm which outperformed several other algorithms and a capacitive wear sensor in quality control. These findings provide essential insight informing study design in digital health research.
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30,767 members
Shailender Kanwar
  • Bio-interfaces Institute, NCRC B20/301W-6D
Raghunath Azhwar
  • Department of Pediatrics and Communicable Diseases
Olga Grushko
  • Division of Cardiovascular Medicine
Ann Arbor, United States