University of Missouri
  • Columbia, Missouri, United States
Recent publications
In a sensor network, estimation performance may degrade when unknown correlations among local estimates are not addressed carefully. This article presents a novel distributed estimation algorithm based on inverse covariance intersection (ICI) for effectively solving the cross-correlation and dynamic state estimation problems in a wireless sensor network. The intermediate results of a set of consensus filters running in parallel are utilized to realize a global fusion of estimates, which involves all agents' local estimates and improves the estimation accuracy. Meanwhile, the global consistency of the proposed algorithm can be guaranteed theoretically since the fusion process considers all local estimates jointly and in a unified way. Furthermore, besides the asymptotic performance, the boundedness and consistency of the fused estimate can be achieved under finite iterations, which demonstrates its robustness and potential in practical applications. A cooperative target tracking problem illustrates the performance of the proposed algorithm.
The Hijacking of Flight 119: How D.B. Cooper Inspired a Skyjacking Craze and the FBI's Battle to Stop It discusses the legend of D.B. Cooper that triggers the most extraordinary eras in American aviation history. In November 1971, Cooper hijacked a Northwest Airlines flight, parachuted from the Boeing 727 with $200,000 in ransom, and was never seen again. The hijacking case remained open for four decades before it was finally determined as a cold case. Over the following seven months of his crime, many air pirates imitated Cooper's crime with varying motivations such as politics, greed, derring-do, and boredom. The Hijacking of Flight 119 also details the impact of Cooper's legend on the public, media, and law enforcement.
Preventing unauthorized access to sensitive data has always been one of the main concerns in the field of information security. Accordingly, various solutions have been proposed to meet this requirement, among which encryption can be considered as one of the first and most effective solutions. The continuous increase in the computational power of computers and the rapid development of artificial intelligence techniques have made many previous encryption solutions not secure enough to protect data. Therefore, there is always a need to provide new and more efficient strategies for encrypting information. In this article, a two-way approach for information encryption based on chaos theory is presented. To this end, a new chaos model is first proposed. This model, in addition to having a larger key space and high sensitivity to slight key changes, can demonstrate a higher level of chaotic behavior compared to previous models. In the proposed method, first, the input is converted to a vector of bytes and first diffusion is applied on it. Then, the permutation order of chaotic sequence is used for diffusing bytes of data. In the next step, the chaotic sequence is used for applying second diffusion on confused data. Finally, to further reduce the data correlation, an iterative reversible rule-based model is used to apply final diffusion on data. The performance of the proposed method in encrypting image, text, and audio data was evaluated. The analysis of the test results showed that the proposed encryption strategy can demonstrate a pattern close to a random state by reducing data correlation at least 28.57% compared to previous works. Also, the data encrypted by proposed method, show at least 14.15% and 1.79% increment in terms of MSE and BER, respectively. In addition, key sensitivity of 10 ⁻²⁸ and average entropy of 7.9993 in the proposed model, indicate its high resistance to brute-force, statistical, plaintext and differential attacks.
Background Interventions such as advance care planning (ACP), technology, or access to euthanasia may increase the sense of control over the end of life. In people with advanced dementia, the loss of cognitive and physical function limits the ability to control care. To date, little is known about the acceptability of these interventions from the perspective of persons with dementia and others involved. This study will examine the cross-cultural acceptability, and factors associated with acceptability, of four end-of-life interventions in dementia which contain an element of striving for control. Also, we report on the development and pilot testing of animation video vignettes that explain the interventions in a standardized manner. Methods Cross-sectional mixed-methods vignette study. We assess acceptability of two ACP approaches, technology use at the end of life and euthanasia in persons with dementia, their family caregivers and physicians in six countries (Netherlands, Japan, Israel, USA, Germany, Switzerland). We aim to include 80 participants per country, 50 physicians, 15 persons with dementia, and 15 family caregivers. After viewing each animation video, participants are interviewed about acceptability of the intervention. We will examine differences in acceptability between group and country and explore other potentially associated factors including variables indicating life view, personality, view on dementia and demographics. In the pilot study, participants commented on the understandability and clarity of the vignettes and instruments. Based on their feedback, the scripts of the animation videos were clarified, simplified and adapted to being less slanted in a specific direction. Discussion In the pilot study, the persons with dementia, their family caregivers and other older adults found the adapted animation videos and instruments understandable, acceptable, feasible, and not burdensome. The CONT-END acceptability study will provide insight into cross-cultural acceptability of interventions in dementia care from the perspective of important stakeholders. This can help to better align interventions with preferences. The study will also result in a more fundamental understanding as to how and when having control at the end of life in dementia is perceived as beneficial or perhaps harmful. Trial registration The CONT-END acceptability study was originally registered at the Netherlands Trial Register (NL7985) at 31 August, 2019, and can be found on the International Clinical Trials Registry Platform.
Laura teaches in a third-grade classroom in the city surrounding the university where she works. She planned a socioscientific issue (SSI) unit on ecosystem interrelationships. Specifically, her SSI unit focused on the reduction in Monarchs migrating through the state due to a decline in prairies. She asked students to consider whether or not a way to work on this problem would be to turn one of the two soccer fields on their playground into a prairie to support Monarch migration through the state. This open case explores a situation in which Laura discovers that her students took their position on this issue very seriously and assumed the outcome of the soccer field was in their hands.
This is a commentary to the case narrative, “I’m Not Stupid in Your Classroom!” written by Deborah Hanuscin.
This is a commentary to the case narrative, ““Arts and Crafts” with a Side of Science” written by Michelle J. Petersen.
The purpose of this study was to understand how players reckon with relentlessly challenging video games by exploring their interactions in a game-specific affinity space. The authors conducted a qualitative thematic analysis of a focal discussion thread on r/EldenRing, a Reddit community, to examine how players lend each other support in response to the game's mechanical, affective, and interpretive difficulty. The findings demonstrate how affinity spaces can play an important role in helping players navigate challenging games like Elden Ring by providing a space for them to strategize, vent, joke, and even philosophize about their experiences with the game. Through this study, the authors suggest that game designers might extend their design perspectives to consider players’ metagaming practices in affinity spaces, where they support one another to construct meaning of their suffering, perhaps leading to more players, more joy, and more joyful players.
OBJECTIVE To describe a novel scoring system of feline pigmented iris lesions prior to utilization of diode laser ablation of progressive pigmented iris lesions and to retrospectively evaluate short- and long-term patient outcomes following transcorneal diode laser ablation. ANIMALS 317 client-owned cats (356 eyes) were included. CLINICAL PRESENTATION Records of cats undergoing diode laser ablation from January 2000 to December 2018 were retrospectively reviewed. A novel clinical grading system to describe severity of feline iris hyperpigmentation was developed. Recorded parameters included signalment, operated-upon eye, presurgical iris pigmentation score, intraocular pressure, visual status, postoperative complications, repeat laser surgery, patient status at last follow-up, time to death, and presumptive or known cause of death. RESULTS Complications included corneal ulceration (25/356 [7%]), glaucoma (18/356 [5%]), uveitis (4/356 [1.1%]), and corneal edema (3/356 [0.8%]). Enucleation was performed in 12 eyes due to blindness and secondary glaucoma. Repeat laser due to continued progression of pigment was performed in 18.5% of eyes. Two study patients were euthanized due to presumptive metastatic disease. Of the 250 cats for whom confirmation was available via phone call or medical records, 240 (96%) were alive at 1 year. CLINICAL RELEVANCE Diode laser ablation appears safe overall and may be effective in decreasing progression of feline iris pigmentation. Complication risks appear minimal.
Background Glycated albumin (GA) is an alternate marker of glucose control that is recommended in situations when hemoglobin A1c is unreliable. One of us (JPC) has examined its use in pregnant women with diabetes since 2019 and regularly observed GA values of 8.0–19.4%, with occasional outliers. However, in a recently recruited cohort of 149 women with and without gestational diabetes, 58% of the samples showed GA results <8.0%, despite no apparent physiological differences. Here we further investigate a subset of these samples using a liquid chromatography-mass spectrometry method (LC-MS/MS). Methods Glycated serum proteins (GSP) were measured using the GlycoGap kit (Diazyme Labs, Poway, CA), an enzymatic method, and subsequently converted to percent glycated albumin (GA%) using the equation provided by the manufacturer.The LC-MS/MS assay was performed according to a previously published protocol. The samples were first reduced and alkylated, then spiked with a blend of two isotope-labeled standards and digested using Glu-C enzyme. The resulting digests were analyzed using the QTRAP 6500+ (AB Sciex, Foster City, CA) coupled with a LC system (Shimadzu, Japan) in MRM mode to provide values representing the percentage of glycated to non-glycated Lys-525 in albumin (MSGA%).Samples from a previously collected cohort (A, n = 78) of pregnant women with and without diabetes, with GA% range of 8.5–24.2%, were analyzed using both methods, and a standard curve (MSGA% vs GA%) was established. Thirty-eight samples with GA <8.0% (cohort B) were then analyzed using the LC-MS/MS method, and the standard curve was used to generate the expected enzymatic GA% results. Results The comparison of the LC-MS/MS and Diazyme methods resulted in a straight-line equation (r2 = 0.84, slope = 1.81, y-intercept = 0.79). For the cohort B samples analyzed by LC-MS/MS, the median MSGA% result was 5.89% (range: 4.32–8.95%). Based on the equation derived from the method comparison (MSGA% vs GA%), the expected median value with the Diazyme enzymatic method would have been 11.48% (range: 8.63–17.02%). These GA% values are well within the typically expected range. Conclusion LC-MS/MS results and GA% calculated from a method comparison curve were within the expected range while original enzymatic results were not, suggesting the presence of an interfering substance. Our hypothesis is that prenatal supplements may lead to elevated ascorbic acid, which is known to cause interference in certain enzymatic assays. We are continuing to investigate this possibility.
Background C-peptide is a useful biomarker for distinguishing among different types of diabetes and is a proxy measure of endogenous insulin production, useful in diabetes management. Additionally, C-peptide tests can be used to diagnose non-diabetic hypoglycemia and insulinoma. However, differences among clinical assays can limit the application of C-peptide testing. To address this issue, efforts are underway to standardize manufacturer assays with serum-based secondary reference materials where values are assigned by a reference LC-MS method. Clinical evidence suggests that patients with diabetes can benefit from residual beta-cell function, yet many clinical assays have high variability at lower levels of C-peptide. Here we explore different approaches for improving sensitivity and selectivity of C-peptide reference measurements with a focus at the lower end of the measurement range. Methods Two methods were developed to evaluate and determine the most effective approach. The first method involved spiking serum samples with isotope-labeled c-peptide (Sigma) and then enriching and enzymatically digesting them. The enrichment process included removing abundant serum proteins by using methanol, followed by centrifugation and filtration through C18 cartridges. The resulting solution was then passed through a strong anion-exchange column after correcting its pH with ammonium formate buffer. The eluent was evaporated, and the residue was dissolved in ammonium carbonate buffer. Enzymatic digestion was performed by adding dithiothreitol and iodoacetamide followed by addition of Glu-C. The digested peptides were then analyzed by LC-MS/MS (QTRAP 6500+) in MRM mode. The second method followed the same steps as the first method, except that the evaporation and digestion step were skipped, and MRM was performed on the intact C-peptide chain. Two separate calibration curves were constructed for each method using isotope labeled c-peptide (Sigma) and certified reference material (National Metrology Institute of Japan) as native c-peptide. Results The first method, which measures intact C-peptide using MRM, had a slope of 1.14 and an intercept of −0.01 nmol/L (Deming regression, R = 0.917) when compared to the reference method. The method demonstrated CV within 0.4%–11.9%. The second method, which quantifies digested peptides, showed a slope of 1.02 and an intercept of −0.21 nmol/L compared to the reference method (Deming regression, R = 0.995). The method demonstrated CV within 4.4–20.0%. Controlling the three MRM transitions improved the specificity and accuracy of the results. For the first method two MRM transitions were adequate. Both methods showed no significant matrix effects. The first method is simpler to implement due to a smaller number of separation steps. Conclusion We have explored two new alternative workflows for C-peptide quantitation that include first, an enzymatic digestion then MRM quantitation and second, MRM quantitation of intact C-peptide. To improve the analytical performance of the methods, further optimization is still required.
OBJECTIVE Apply the 3-site echocardiographic metrics utilized to assess pulmonary hypertension (PH) probability in dogs and humans to feline echocardiographic examinations to investigate the translatability of this scheme and subsequent enhancement of detection of PH in cats. ANIMALS 27 client-owned cats (euthyroid [n = 11] and hyperthyroid [16]). METHODS This was a single-center, prospective, observational case-control study. Demographic, physical examination, and echocardiographic data from hyperthyroid and euthyroid cats were compared via Fisher exact test and Kruskal-Wallis test. RESULTS Hyperthyroid versus euthyroid cats had significantly greater right atrial area index values and were more likely to have late-peaking main pulmonary artery pulsed-wave flow profiles. Two hyperthyroid cats had measurable tricuspid regurgitation tracings (one with a high probability of PH and another with a low probability of PH). CLINICAL RELEVANCE Hyperthyroid cats demonstrated altered pulmonary arterial hemodynamics and lacked consistent intermediate or high probability of PH. The 3-site echocardiographic metrics scheme is applicable for the evaluation of right-sided cardiac and pulmonary arterial hemodynamics in cats. Further research is needed to determine reference ranges in larger populations of healthy cats and those with high clinical suspicion for PH.
Previous research has highlighted the enduring negative impact of family economic adversity on youth emotional well-being. However, the longitudinal mechanism underlying the link between economic adversity and emotional distress is less explored. The present study examined the longitudinal pathway of parent economic adversity, and parent and adolescent emotional distress at age 16, parental support at age 21, youth self-esteem and mastery at age 23, and adult emotional distress at age 27. Data came from the Family Transitions Project (N = 441, 57% female), a 30-year study of families from the rural Midwest. Structural equation models revealed that economic adversity exerted a long-term negative influence on adult emotional well-being through parent and adolescent emotional distress and youth self-esteem and mastery. Additionally, parental support was associated with adult emotional distress through youth self-esteem and mastery. The current study advances our understanding of youth emotional well-being by suggesting a longitudinal family process and resilience pathways from adolescence to early adulthood.
An inherent limitation of many popular community detection methods, such as the walktrap and spin glass algorithms, is that they do not allow vertices to have membership in more than one community. Clique percolation remedies this limitation by allowing overlapping communities but does not necessarily produce solutions in accordance with the standard definition of ‘community’ (i.e., a dense subgraph of the network), often fails to assign all vertices to at least one community and presents formidable model selection challenges. In this paper, we propose a set-covering approach to overlapping community detection that enables overlapping communities to be assembled from maximal cliques, or from candidate communities formed from k-1 adjacent cliques. The promise of this new approach is demonstrated via comparison to clique percolation in a simulation experiment, as well as through application to an empirical psychological network.
Water withdrawals for irrigation at an unsustainable rate resulted in a decline in the groundwater levels in the Mississippi River Valley Alluvial Aquifer (MRVAA) in the central southern USA. This drawdown of groundwater threatens agricultural production in the Mississippi Delta, an important agricultural region in the state of Mississippi, USA. Effective and efficient use of available resources is important to sustain and enhance agricultural productivity in this area. This study assessed the opinions of farmers on water conservation management practices and technologies that improve irrigation management and save water in the Mississippi Delta region based on data collected in an irrigation survey conducted in 2012. Most landowners believed that water conservation practices were effective in reducing irrigation water use without reducing maximum crop yields and have a positive return on investment. Land forming, tailwater recovery system, on‐farm storage, instream weirs to pond surface water, computerized hole selection for furrow irrigation, short irrigation runs, and irrigation scheduling were considered efficient water conservation technologies by landowners. Perceptions about use of different practices also depend upon the crops produced by the respondents. About 20 to 24% and 14.9 to 86% of survey respondents thought that on‐farm storage and center pivot, respectively, were inefficient water conservation practices for irrigating crops in the Mississippi Delta. The adoption of these practices may be increased if the landowners know the economic returns of implementing them.
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10,559 members
Brian Bostick
  • Department of Internal Medicine
Vaibhav Mishra
  • School of Medicine
Mayank Mittal
  • Department of Internal Medicine
Andrew Melnyk
  • Department of Philosophy
Kamal Singh
  • Department of Veterinary Pathobiology
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