Washington State University
  • Pullman, United States
Recent publications
Electrochemical energy storage (EES) is increasingly critical for development and applications of numerous technologies or new products, such as portable electronics, electric vehicles, and large-scale energy storage systems. The expanding market of EES requires products that are low cost, environmentally friendly, and with high energy density. Natural proteins are abundant bio-macromolecules and possess numerous useful functional groups through millions of years of evolution. By the rational control of the protein molecular architectures, we can effectively develop important component materials with functionalities for energy storage systems via appropriately utilizing the functional groups of proteins. Therefore, tremendous research efforts on application of natural proteins for enhancing the performance of EES have been reported. In this book, advanced strategies for adopting various natural proteins to development of the components of EES are comprehensively summarized, such as protein-derived active materials, separators, binders, electrolytes, and more. The advantages and challenges of the various strategies are discussed in detail. Finally, future perspectives of the protein-based strategies toward high-performance EES are proposed.
The explicit reference governor (ERG) is an add on unit that provides the constraint handling capability to a pre-stabilized system by providing the system with an applied reference which is the best approximation of the desired reference at any time and converges to the desired reference. One of the main strengths of ERG is that it does not make use of any online optimization, which makes it an appropriate solution for real-time applications; in particular, it has been shown that ERG has potential to control safety-critical systems that are subject to time-varying constraints. This paper proposes a systematic approach for designing an ERG for the control of systems that are subject to the intersections of multiple time-varying concave constraints. Under certain conditions on the change-rate of the constraints and system dynamics, constraints satisfaction and convergence properties are proven rigorously. The effectiveness of the proposed scheme is demonstrated through simulation studies on two relevant problems in the field of robotics: i) automated packaging line; and ii) non-cooperative household robots.
Increasing user density and capacity in next-generation systems presents a need for fine beam angle resolution especially in the emerging upper mid-band 7247-24 GHz frequency regime. This paper presents a scalable area-and energy-efficient quadrature generator targeted for beamforming receivers with a multi-stage phase-shifting polyphase filter providing continuous beam angle resolution. When complemented with vector modulation for coarse tuning, a phase range of 360 ^{\circ} is achieved realizing a phase-shifter-less implementation leveraging slice-based receiver architecture and polyphase filters. Fabricated in 65nm CMOS, the phase-shifting polyphase filter occupies 0.003 mm 2 , consumes 0.25 mW, and achieves an Image Rejection Ratio >> 58 dB over the entire phase range. The quadrature generator is demonstrated with a proof-of-concept receiver array operating between 7.28-7.78 GHz consuming 37 mW per element occupying 1.26 mm 2 .
Ruminants have the ability to digest human-inedible plant materials, due to the symbiotic relationship with the rumen microbiota. Rumen microbes supply short chain fatty acids, amino acids, and vitamins to dairy cows that are used for maintenance, growth, and lactation functions. The main goal of this study was to investigate gene-microbiome networks underlying feed efficiency traits by integrating genotypic, microbial, and phenotypic data from lactating dairy cows. Data consisted of dry matter intake (DMI), net energy secreted in milk, and residual feed intake (RFI) records, SNP genotype, and 16S rRNA rumen microbial abundances from 448 mid-lactation Holstein cows. We first assessed marginal associations between genotypes and phenotypic and microbial traits through genomic scans, and then, in regions with multiple significant hits, we assessed gene-microbiome-phenotype networks using causal structural learning algorithms. We found significant regions co-localizing the rumen microbiome and feed efficiency traits. Interestingly, we found three types of network relationships: (1) the cow genome directly affects both rumen microbial abundances and feed efficiency traits; (2) the cow genome (Chr3: 116.5 Mb) indirectly affects RFI, mediated by the abundance of Syntrophococcus, Prevotella, and an unknown genus of Class Bacilli; and (3) the cow genome (Chr7: 52.8 Mb and Chr11: 6.1–6.2 Mb) affects the abundance of Rikenellaceae RC9 gut group mediated by DMI. Our findings shed light on how the host genome acts directly and indirectly on the rumen microbiome and feed efficiency traits and the potential benefits of the inclusion of specific microbes in selection indexes or as correlated traits in breeding programs. Overall, the multistep approach described here, combining whole-genome scans and causal network reconstruction, allows us to reveal the relationship between genome and microbiome underlying dairy cow feed efficiency.
Microplastic fibers (MPF) are the largest fraction of microplastics in the environment by mass. The endpoints of these contaminants' movement is generally known at large‐scale (i.e., their origins and where they end up), but the mechanics of how they get to those sinks remains poorly understood. The objective of this work was to improve understanding of the mechanisms driving MPF migration through terrestrial systems by directly imaging their motion through idealized representations of porous media. Monofilament line with 0.3 mm diameter was passed through a bench‐scale, pseudo‐2d flow cell to capture trajectories of MPFs of three different lengths and trajectories of passive micro‐bead tracers were also captured. Video processing and automated image analysis converted the video of the experiments into a database of trajectories, allowing comparison of the experimental data to various numerical models. Simple advection‐dispersion models were adequate for modeling the passive tracer but did not provide a good description of MPF transport. A physics‐based, distributed model was able to generate realistic trajectories through the domain, but the speeds of the fibers in the initial simulation were too fast, despite working well for the passive tracer. Adding a delay (waiting time) process resulted in good description of the trajectories and travel times. The specifics of the delay process could not be deduced from these experiments, but its overall impact on transport provides mechanistic insights. These direct observation of the trajectories and speeds of MPFs moving through porous media show that MPFs likely have strong interactions with their surroundings.
In inland water covering lakes, reservoirs, and ponds, the gas exchange of slightly soluble gases such as carbon dioxide, dimethyl sulfide, methane, or oxygen across a clean and nearly flat air‐water interface is routinely described using a water‐side mean gas transfer velocity kL‾ kL\overline{{k}_{L}}, where overline indicates time or ensemble averaging. The micro‐eddy surface renewal model predicts kL‾=αoSc−1/2νϵ‾1/4 kL=αoSc1/2(νϵ)1/4\overline{{k}_{L}}={\alpha }_{o}S{c}^{-1/2}{\left(\nu \overline{{\epsilon}}\right)}^{1/4}, where Sc ScSc is the molecular Schmidt number, ν ν\nu is the water kinematic viscosity, and ϵ‾ ϵ\overline{{\epsilon}} is the waterside mean turbulent kinetic energy dissipation rate at or near the interface. While αo=0.39−0.46 αo=0.390.46{\alpha }_{o}=0.39-0.46 has been reported across a number of data sets, others report large scatter or variability around this value range. It is shown here that this scatter can be partly explained by high temporal variability in instantaneous ϵ ϵ{\epsilon} around ϵ‾ ϵ\overline{{\epsilon}}, a mechanism that was not previously considered. As the coefficient of variation CVe (CVe)\left(C{V}_{e}\right) in ϵ ϵ{\epsilon} increases, αo αo{\alpha }_{o} must be adjusted by a multiplier 1+CVe2−3/32 (1+CVe2)3/32{\left(1+C{V}_{e}^{2}\right)}^{-3/32} that was derived from a log‐normal model for the probability density function of ϵ ϵ{\epsilon}. Reported variations in αo αo{\alpha }_{o} with a macro‐scale Reynolds number can also be partly attributed to intermittency effects in ϵ ϵ{\epsilon}. Such intermittency is characterized by the long‐range (i.e., power‐law decay) spatial auto‐correlation function of ϵ ϵ{\epsilon}. That αo αo{\alpha }_{o} varies with a macro‐scale Reynolds number does not necessarily violate the micro‐eddy model. Instead, it points to a coordination between the macro‐ and micro‐scales arising from the transfer of energy across scales in the energy cascade.
Environmental risk assessment (ERA) is critical for protecting life by predicting population responses to contaminants. However, routine toxicity testing often examines only one genotype from surrogate species, potentially leading to inaccurate risk assessments, as natural populations typically consist of genetically diverse individuals. To evaluate the importance of intraspecific variation in translating toxicity testing to natural populations, we quantified the magnitude of phenotypic variation between 20 Daphnia magna clones exposed to two levels of microcystins, a cosmopolitan cyanobacterial toxin. We observed significant genetic variation in survival, growth, and reproduction, which increased under microcystins exposure. Simulations of survival showed that using a single genotype for toxicity tolerance estimates on average failed to produce accurate predictions within the 95% confidence interval over half of the time. Whole genome sequencing of the 20 clones tested for correlations between toxicological responses and genomic divergence, including candidate loci from prior gene expression studies. We found no overall correlations, indicating that clonal variation, rather than variation at candidate genes, predicts population-level responses to toxins. These results highlight the importance of incorporating broad intraspecific genetic variation, without focusing specifically on variation in candidate genes, into ERAs to more reliably predict how local populations will respond to contaminants.
In the context of climate change, drought is a critical challenge that drastically limits the growth and productivity of crops. Seminal roots and coleoptile play an important role in crop establishment and growth. This study assessed the adaptive changes at an early stage of development using a resurrection approach on 40 populations of wild barley [Hordeum vulgare subsp. spontaneum (C. Koch)] that were collected in 1991 and recollected from the same sites in 2014. Significant genetic variability (P < 0.001) was detected for seminal shoot and root traits assessed based on collection sites and with collection-time interactions. All traits except root length showed an increase in broad-sense heritability (h²) and diversity in the population collected in 2014, with root number and first leaf length showing the highest values (68% and 57%, respectively). The two populations diverged into two distinctive structure categories: a conserved structure and an evolved structure. Moreover, the study revealed a trend in adaptative changes of the populations by grouping them according to their eco-geographical pattern, such as a better shoot and seminal roots traits expression that allows the plant to respond to increases in drought from the north to the south over time. These results provide useful information on the responses of crop wild relatives to environmental pressures and highlight the importance of in-situ conservation in the context of climate change adaptation and sustainability of crop improvement.
The rising environmental awareness has spurred the extensive use of green materials in electronic applications, with bio-organic materials emerging as attractive alternatives to inorganic and organic materials due to their natural biocompatibility, biodegradability, and eco-friendliness. This study showcases the natural rubber (NR) based resistive switching (RS) memory devices and how varying sulphur concentrations (0–0.8 wt.%) in NR thin films impact the RS characteristics. The NR was formulated and processed into a thin film deposited on an indium tin oxide substrate as the bottom electrode and with an Ag film as the top electrode. The addition of sulphur modifies the degree of crosslinking in the NR thin film, from which the concentration of –C=C– group and density of defect site (S⁺) are affected, and hence the RS behavior of the memory device. The devices exhibit bipolar resistance with symmetric switching characteristics which are attributed to the formation of conductive paths facilitate by electron transport along –C=C– and S⁺ defect sites between the two electrodes. Notably, a sample with 0.2 wt.% sulphur exhibits a high ON/OFF ratio (10⁴), a large memory window (5.5 V), prolonged data retention (10 yrs), and reliable endurance (120 cycles). These findings highlight the potential of NR as a promising material for eco-friendly resistive-switching random access memory applications.
Sound speed measurements in shock compressed solids have long been valuable for the development of equations of state at extreme conditions, shock-induced phase transformations, and a comprehensive characterization of the thermophysical response of high-pressure standards. We present results from plate impact experiments to 190 GPa to determine the longitudinal sound speed in copper—an important high-pressure standard. Surprisingly, the sound speeds determined using the two most common experimental techniques—the front surface impact (FSI) approach and the release wave overtake (RWO) approach—diverge significantly for stresses greater than ∼100 GPa. Further analyses, including numerical simulations, show that the FSI experiments provide the correct sound speeds and that fundamental assumptions underlying the RWO method are likely violated due to the complex release response of shock compressed copper. The sound speeds determined using the FSI approach provide for a more accurate high-pressure description of copper in dynamic compression experiments. The present findings are in contrast to the results for shock compressed silver [Wallace et al., Phys. Rev. B 104, 214106 (2021)], where both methods provided consistent sound speed results. Thus, the findings presented here demonstrate the need to experimentally verify the validity of the RWO method on a case-by-case basis. Finally, we note that even at the high stresses in the present work, the copper unloading response shows a time-dependent, quasielastic response often observed in metals at lower stresses.
The study of One Million U.S. Radiation Workers and Veterans, the Million Person Study (MPS), examines the health consequences, both cancer and non-cancer, of exposure to ionizing radiation received gradually over time. Recently the MPS has focused on mortality patterns from neurological and behavioral conditions, e.g., Parkinson’s disease, Alzheimer’s disease, dementia, and motor neuron disease such as amyotrophic lateral sclerosis. A fuller picture of radiation-related late effects comes from studying both mortality and the occurrence (incidence) of conditions not leading to death. Accordingly, the MPS is identifying neurocognitive diagnoses from fee-for-service insurance claims from the Centers for Medicare and Medicaid Services (CMS), among Medicare beneficiaries beginning in 1999 (the earliest date claims data are available). Linkages to date have identified ∼540,000 workers with available health information. Such linkages provide individual information on important co-factor and confounding variables such as smoking, alcohol consumption, blood pressure, obesity, diabetes and many other health and demographic characteristics. The total person-level set of time-dependent variables, outcomes, organ-specific dose measures, co-factors, and demographics will be massive and much too large to be evaluated with standard software. Thus, development of specialized open-source software designed for large datasets (Colossus) is nearly complete. The wealth of information available from CMS claims data, coupled with individual dose reconstructions, will thus greatly enhance the quality and precision of health evaluations for this new field of low-dose radiation and neurocognitive effects.
The American radium dial worker (RDW) cohort of over 3,200 persons is being revisited as part of the Million Person Study (MPS) to include a modern approach to RDW dosimetry. An exceptional source of data and contextualization in this project is an extensive collection of electronic records (requiring 43 gigabytes (GB) of storage) digitized from existing microfilm and microfiche housed at the United States Transuranium and Uranium Registries (USTUR). Although the type, extent, and quality (e.g., legibility) of record(s) varies between individuals, the remarkable occupational, medical and demographic data include in vivo radiation measurements (e.g., radon breath, whole body counts), autopsy results, medical records (including copies of radiographs), interviews over the years, and correspondence. Of particular dosimetric interest are the details of radiation measurements. For example, there are some instances where hand-written and transcribed values are both available, along with notes providing context for why a particular measurement in a time series of measurements was chosen to assign an intake, or if there were concerns about a particular measurement. Born prior to 1935, RDW have nearly all passed away. Thus, the updated dosimetry, especially for the bone, will allow the correlation of lifetime cumulative dose with radiation risk. Here we review typical information available in this collection of historical records, highlighting some interesting finds, and discuss the relevance to current and ongoing work related to updating the dosimetry of the RDW in the Million Person Study, including providing an example of the usefulness of information contained in these records.
This essay offers a critique of Gabriel Abend’s call for more action and less abstraction in social theory. The critique questions Abend’s insistence on pragmatic presentism—research that can be used tomorrow—and his implicit rejection of our time-honored commitment to construct clarity and rigor in theory. Abend’s insistent focus on the present ignores a long history of pragmatism in both social and management theory that has served our profession well. More importantly, his argument misinterprets pragmatism as a rejection of theory when, in fact, pragmatism suggests precisely the opposite.
Background Insomnia is more prevalent in individuals with Autism Spectrum Disorder (ASD), can worsen core-symptoms and reduces quality of life of both individuals and caregivers. Although ASD is four times more prevalent in males than females, less is known about sex specific sleep differences in autistic individuals. Recent ASD studies suggest that sleep problems may be more severe in females, which aligns with the sex bias seen in insomnia for the general population. We have previously shown that male mice with a mutation in the high confidence ASD gene Shank3, Shank3 ∆C , recapitulate most aspects of the ASD insomnia phenotype. The objective of the present study was to leverage the Shank3 ∆C model to investigate sex-specific effects in sleep using polysomnography. Methods Adult male and female Shank3 ∆C and wildtype (WT) littermates were first recorded for 24 h of baseline recordings. Subsequently, they were sleep deprived (SD) for five hours via gentle handling and allowed 19 h of recovery sleep to characterize the homeostatic response to SD. Vigilance states (rapid eye movement (REM) sleep, non-rapid eye movement (NREM) sleep and wake) were assigned by manual inspection using SleepSign. Data processing, statistical analysis and visualization were conducted using MATLAB. Results Sex and genotype effects were found during baseline sleep and after SD. At baseline, male Shank3 ∆C mice sleep less during the dark period (active phase) while female Shank3 ∆C mice sleep less during the light period (rest phase) and sleep more during the dark period. Both male and female Shank3 ∆C mice show reduced spectral power in NREM sleep. We detect a significant effect of sex and genotype in sleep onset latency and homeostatic sleep pressure (sleepiness). In addition, while male Shank3 ∆C mice fail to increase sleep time following SD as seen in WT, female Shank3 ∆C mice decrease sleep time. Conclusions Overall, our study demonstrates sex differences in sleep architecture and homeostatic response to SD in adult Shank3 ∆C mice. Thus, our study demonstrates an interaction between sex and genotype in Shank3 ∆C mice and supports the use of the Shank3 ∆C model to better understand mechanisms contributing to the sex differences in insomnia in ASD in clinical populations.
Life history theory predicts increased parental investment comes with fitness costs, often expressed as negative effects on survival and future reproduction. To better understand the costs of reproduction and life history trade‐offs, we evaluated calcium supplementation at a high‐elevation site in Colorado as a novel approach to experimentally alter reproductive investment in nesting female Tachycineta bicolor (tree swallow). Calcium is a nutrient critical to avian reproduction as the intake of natural calcium is essential for egg production, embryo development, and nestling growth. Altering calcium availability exclusively during the breeding season allowed examination of individual biological responses to experimental modification of reproduction, as well as the reproductive costs associated with egg production and laying an entire clutch. As a functional endpoint and proxy for fitness and longevity, telomere length was measured at the beginning and end of each breeding season. Telomeres—protective “caps” at the ends of chromosomes—have been shown to shorten with aging and a variety of stressors, including higher reproductive output. Results demonstrate that tree swallow mothers supplemented with calcium during the breeding season experience higher reproductive output and produce offspring with longer telomeres, which came at the cost of relatively shorter telomeres during the reproductive season. These findings provide additional support for reproductive trade‐offs, and also challenge previous calcium supplementation studies that suggest excess calcium reduces the cost of reproduction.
Drought predisposes forest trees to bark beetle‐induced mortality, but the physiological mechanisms remain unclear. While drought‐induced water and carbon limitations have been implicated in defensive failure and tree susceptibility, evidence demonstrating how these factors interact is scarce. We withheld water from mature, potted Pinus edulis and subsequently applied a double‐stem girdle to inhibit carbohydrate transport from the crown and roots. Within this isolated segment we then elicited a defense response by inoculating trees with a bark beetle‐fungal symbiont (Ophiostoma sp.). We quantified local mono‐ and sesquiterpenes (MST), nonstructural carbohydrates (NSC), and pressure potential of the inner bark. Both drought‐stressed and watered trees had similar NSC concentrations just before inoculation and depleted NSC similarly following inoculation, yet MST induction (i.e. increased concentration and altered composition) was constrained only in drought‐stressed trees. Thus, NSC consumption was largely unrelated to de novo MST synthesis. Instead, stoichiometric calculations show that induction originated largely from stored resin. Watered trees experiencing higher pressure potentials consistently induced higher MST concentrations. We demonstrate the importance of preformed resin toward an induced MST response in a semi‐arid conifer where drought‐constraints on defense occurred through biophysical limitations (i.e. reduced turgor hindering resin transport) rather than through substrate limitation.
Carvacrol is a potent antimicrobial and anti‐inflammatory agent, while curcumin possesses antioxidant, anti‐inflammatory, and anticancer properties. These phytochemicals have poor solubility, bioavailability, and stability in their free form. Nanoencapsulation can reduce these limitations with enhanced translational capability. Integrating nanocarriers with 3D‐printed calcium phosphate (CaP) scaffolds presents a novel strategy for bone regeneration. Carvacrol and curcumin‐loaded nanoparticles (CC‐NP) synthesized with melt emulsification produced negatively charged, monodispersed particles with a hydrodynamic diameter of ≈127 nm. Their release from the scaffold shows a biphasic release under physiological and acidic conditions. At pH 5.0, the CC‐NP exhibits a 53% release of curcumin and nearly 100% release of carvacrol, compared to 19% and 36% from their respective drug solutions. At pH 7.4, ≈40% of curcumin and 76% of carvacrol releases, highlighting their pH‐sensitive release mechanism. In vitro studies demonstrate a 1.4‐fold increase in osteoblast cell viability with CC‐NP treatment. CC‐NP exhibit cytotoxic effects against osteosarcoma cells, reducing cell viability by ≈2.9‐fold. The antibacterial efficacy of CC‐NP evaluated against Staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA) exhibiting 98% antibacterial efficacy. This approach enhances therapeutic outcomes and minimizes the potential side effects associated with conventional treatments, paving the way for innovative applications in regenerative medicine.
We develop a novel construct, diversion risk, defined as the potential for post‐retail diversion that results from increased sales of hazardous goods. We examine diversion risk in the context of prescription opioid sales in the United States. We ask how supply base attributes and nonprofit ownership influence the creation of opioid diversion risk. We use performance‐outcome expectancy theory to hypothesize that pharmacies organize supply bases to help them avoid negative evaluations and that nonprofit ownership alters expectancy concerning legal but questionable behavior. We develop and test multilevel hypotheses explaining how supply base complexity, chain size, and nonprofit ownership influence diversion risk. Our analysis of DEA data from 2006 to 2019 finds that after accounting for other attributes, supply base complexity is positively related to diversion risk, within and between firms. Retail chain size is negatively related to diversion risk in the within‐firm model, but positively in the between firm model. Testing our nonprofit hypothesis reveals that nonprofit pharmacies also use size and supply base complexity to manage diversion risk. This research sheds light on the dynamics of diversion risk in pharmaceutical supply chains. It has practical implications for the industry, potentially informing future policy and practice addressing this critical issue.
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11,870 members
Naidu Rayapati
  • Prosser Irrigated Agriculture Research and Extension Center (IAREC)
Catherine Van Son
  • College of Nursing
Hubert G Schwabl
  • School of Biological Sciences
Narayanan Srividya
  • Institute of Biological Chemistry
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Pullman, United States