Showing papers by "University of Memphis published in 2016"

Pure and stable metallic phase molybdenum disulfide nanosheets for hydrogen evolution reaction

Abstract: Metallic molybdenum disulfide is a metastable phase of the material. Here, the authors synthesize two-dimensional metallic molybdenum disulfide nanosheets, stabilized by adsorbed aqueous monolayers, and evaluate their catalytic hydrogen evolution activity.

DNA Methylation in Newborns and Maternal Smoking in Pregnancy: Genome-wide Consortium Meta-analysis

Abstract: Epigenetic modifications, including DNA methylation, represent a potential mechanism for environmental impacts on human disease. Maternal smoking in pregnancy remains an important public health problem that impacts child health in a myriad of ways and has potential lifelong consequences. The mechanisms are largely unknown, but epigenetics most likely plays a role. We formed the Pregnancy And Childhood Epigenetics (PACE) consortium and meta-analyzed, across 13 cohorts (n = 6,685), the association between maternal smoking in pregnancy and newborn blood DNA methylation at over 450,000 CpG sites (CpGs) by using the Illumina 450K BeadChip. Over 6,000 CpGs were differentially methylated in relation to maternal smoking at genome-wide statistical significance (false discovery rate, 5%), including 2,965 CpGs corresponding to 2,017 genes not previously related to smoking and methylation in either newborns or adults. Several genes are relevant to diseases that can be caused by maternal smoking (e.g., orofacial clefts and asthma) or adult smoking (e.g., certain cancers). A number of differentially methylated CpGs were associated with gene expression. We observed enrichment in pathways and processes critical to development. In older children (5 cohorts, n = 3,187), 100% of CpGs gave at least nominal levels of significance, far more than expected by chance (p value < 2.2 × 10(-16)). Results were robust to different normalization methods used across studies and cell type adjustment. In this large scale meta-analysis of methylation data, we identified numerous loci involved in response to maternal smoking in pregnancy with persistence into later childhood and provide insights into mechanisms underlying effects of this important exposure.

Azo dyes and human health: A review.

Abstract: Synthetic azo dyes are widely used in industries. Gerhardt Domagk discovered that the antimicrobial effect of red azo dye Prontosil was caused by the reductively cleaved (azo reduction) product sulfanilamide. The significance of azo reduction is thus revealed. Azo reduction can be accomplished by human intestinal microflora, skin microflora, environmental microorganisms, to a lesser extent by human liver azoreductase, and by nonbiological means. Some azo dyes can be carcinogenic without being cleaved into aromatic amines. However, the carcinogenicity of many azo dyes is due to their cleaved product such as benzidine. Benzidine induces various human and animal tumors. Another azo dye component, p-phenylenediamine, is a contact allergen. Many azo dyes and their reductively cleaved products as well as chemically related aromatic amines are reported to affect human health, causing allergies and other human maladies.

Preventing and Managing Toxicities of High-Dose Methotrexate

Abstract: High-dose methotrexate (HDMTX), defined as a dose higher than 500 mg/m2, is used to treat a range of adult and childhood cancers. Although HDMTX is safely administered to most patients, it can cause significant toxicity, including acute kidney injury (AKI) in 2%-12% of patients. Nephrotoxicity results from crystallization of methotrexate in the renal tubular lumen, leading to tubular toxicity. AKI and other toxicities of high-dose methotrexate can lead to significant morbidity, treatment delays, and diminished renal function. Risk factors for methotrexate-associated toxicity include a history of renal dysfunction, volume depletion, acidic urine, and drug interactions. Renal toxicity leads to impaired methotrexate clearance and prolonged exposure to toxic concentrations, which further worsen renal function and exacerbate nonrenal adverse events, including myelosuppression, mucositis, dermatologic toxicity, and hepatotoxicity. Serum creatinine, urine output, and serum methotrexate concentration are monitored to assess renal clearance, with concurrent hydration, urinary alkalinization, and leucovorin rescue to prevent and mitigate AKI and subsequent toxicity. When delayed methotrexate excretion or AKI occurs despite preventive strategies, increased hydration, high-dose leucovorin, and glucarpidase are usually sufficient to allow renal recovery without the need for dialysis. Prompt recognition and effective treatment of AKI and associated toxicities mitigate further toxicity, facilitate renal recovery, and permit patients to receive other chemotherapy or resume HDMTX therapy when additional courses are indicated. Implications for practice High-dose methotrexate (HDMTX), defined as a dose higher than 500 mg/m2, is used for a range of cancers. Although HDMTX is safely administered to most patients, it can cause significant toxicity, including acute kidney injury (AKI), attributable to crystallization of methotrexate in the renal tubular lumen, leading to tubular toxicity. When AKI occurs despite preventive strategies, increased hydration, high-dose leucovorin, and glucarpidase allow renal recovery without the need for dialysis. This article, based on a review of the current associated literature, provides comprehensive recommendations for prevention of toxicity and, when necessary, detailed treatment guidance to mitigate AKI and subsequent toxicity.

Critical Race Theory in Education : All God's Children Got a Song

Abstract: Foreword: The Evolving Role of Critical Race Theory in Educational Scholarship Gloria Ladson-Billings Introduction: All God's Children Got a Song Section I: Critical Race Theory and Education in Context 1. Toward a Critical Race Theory of Education Gloria Ladson-Billings and William F. Tate, IV 2. And We Are Still Not Saved: Critical Race Theory in Education Ten Years Later Adrienne Dixson and Celia Rousseau Section II: Critical Race Theory Constructs 3. The First Day of School: A CRT Story Celia Rousseau and Adrienne Dixson 4. Peddling Cackwards: Reflections of Plessy and Brown in the Rockford Public Schools De Jure Desegregation Efforts Thandeka Chapman 5. 'Proving Your Skin is White, You Can Have Everything': Race, Racial Identity and the Property Rights in Whiteness in the Supreme Court Case of Josephine DeCuir Jessica DeCuir-Gunby 6. Keeping it Real: Race and Education in Memphis Celia Rousseau 7. Critical Race Perspectives on Desegregation: The Forgotten Voices of Black Educators Jerome Morris 8. Parent(s): The Biggest Influences in the Education of African American Football Student-Athletes Jamel Donnor Section III: The Interdisciplinary Nature of Critical Race Theory 9. Whose Culture has Capital? A Critical Race Theory Discussion of Community Cultural Wealth Tara J. Yosso 10. Critical Race Ethnography in Education: Narrative, Inequality, and the Problem of Epistemology Garret Duncan 11. The Fire This Time: Jazz, Research and Critical Race Theory Adrienne Dixson Section IV: Critical Race Theory in US Classrooms and Internationally 12. Where the Rubber Hits the Road: CRT Goes to High School David Stovall 13. Critical Race Theory Beyond North America: Towards a Trans-Atlantic Dialogue on Racism and Antiracism in Educational Theory and Praxis David Gillborn Conclusion 14. Ethics, Engineering, and the Challenge of Racial Reform in Education William F. Tate, IV

Learning Representations from EEG with Deep Recurrent-Convolutional Neural Networks

Abstract: One of the challenges in modeling cognitive events from electroencephalogram (EEG) data is finding representations that are invariant to inter- and intra-subject differences, as well as to inherent noise associated with such data. Herein, we propose a novel approach for learning such representations from multi-channel EEG time-series, and demonstrate its advantages in the context of mental load classification task. First, we transform EEG activities into a sequence of topology-preserving multi-spectral images, as opposed to standard EEG analysis techniques that ignore such spatial information. Next, we train a deep recurrent-convolutional network inspired by state-of-the-art video classification to learn robust representations from the sequence of images. The proposed approach is designed to preserve the spatial, spectral, and temporal structure of EEG which leads to finding features that are less sensitive to variations and distortions within each dimension. Empirical evaluation on the cognitive load classification task demonstrated significant improvements in classification accuracy over current state-of-the-art approaches in this field.

American Brain Tumor Association Adolescent and Young Adult Primary Brain and Central Nervous System Tumors Diagnosed in the United States in 2008-2012

Abstract: Brain and central nervous system (CNS) tumors found in adolescents and young adults (AYA) are a distinct group of tumors that pose challenges not only to treatment but also to reporting. Overall, cancer that occurs in this age group is biologically distinct from those that occur in both younger and older age groups1,2 posing significant challenges for clinicians. The most commonly diagnosed histologies in AYA vary from those in both children age (0-14 years), and older adults (40+ years).3,4 Prognosis and expected survival also varies between younger and older adults, with those who are diagnosed with brain and CNS tumors at younger ages having significantly longer survival. Despite this survival advantage, recent analyses have reported that while cancer survival has been improving overall, AYA have not experienced these same increases in survival and in some cases may have worse survival than those cancers diagnosed in persons over age 40 years.5 This report provides an in depth analyses of the epidemiology of brain and CNS tumors in adolescents and young adults in the United States (US), and is the first report to provide histology-specific statistics in this population for both malignant and non-malignant brain and other CNS tumors. In 2006, the National Institutes of Health, the National Cancer Institute (NCI) and the LiveStrong Young Adult Alliance conducted a Progress Review Group to investigate AYA Oncology entitled Research and care imperatives for adolescents and young adults with cancer: A Report of the Adolescent and Young Adult Oncology Progress Review Group. This group established the standard age range for the AYA group as 15-39 years. This is the age range used by the Surveillance Epidemiology and End Results (SEER) program of the NCI, as well as in the 2015 CBTRUS Statistical Report.3,6 Brain tumors and other CNS tumors are less common in AYA than in older adults, but they have a higher incidence than brain tumors in children (age 0-14 years).3 Non-malignant tumors are significantly more common in AYA than children (Average annual age adjusted incidence in age 15-39 years: 6.17 per 100,000; age 0-14 years: 0.79 per 100,000), while malignant tumors are slightly more common in those age 0-14 years (Average annual age adjusted incidence in 15-39 years old: 3.26 per 100,000; 0-14 years old: 3.73 per 100,000). While a rare cancer overall, brain and CNS tumors are among the most common cancers occurring in this age group (4.4% of all cancers in those age 15-39 years as compared to 32.4% in children age 0-14 years, and 2.2% of cancers in adults age 40+ years).3,4,7 Malignant brain and CNS tumors are the 11th most common cancer and the 3rd most common cause of cancer death7,8 in the AYA population. Incidence rates of brain tumors overall as well as specific histologies vary significantly by age. It is, therefore, important to provide an accurate statistical assessment of brain and other CNS tumors in the adolescent and young adult population to better understand their impact on the US population and to serve as a reference for afflicted individuals, for researchers investigating new therapies and for clinicians treating patients.

Hierarchical filters determine community assembly of urban species pools

Abstract: The majority of humanity now lives in cities or towns, with this proportion expected to continue increasing for the foreseeable future. As novel ecosystems, urban areas offer an ideal opportunity to examine multi-scalar processes involved in community assembly as well as the role of human activities in modulating environmental drivers of biodiversity. Although ecologists have made great strides in recent decades at documenting ecological relationships in urban areas, much remains unknown, and we still need to identify the major ecological factors, aside from habitat loss, behind the persistence or extinction of species and guilds of species in cities. Given this paucity of knowledge, there is an immediate need to facilitate collaborative, interdisciplinary research on the patterns and drivers of biodiversity in cities at multiple spatial scales. In this review, we introduce a new conceptual framework for understanding the filtering processes that mold diversity of urban floras and faunas. We hypothesize that the following hierarchical series of filters influence species distributions in cities: (1) regional climatic and biogeographical factors; (2) human facilitation; (3) urban form and development history; (4) socioeconomic and cultural factors; and (5) species interactions. In addition to these filters, life history and functional traits of species are important in determining community assembly and act at multiple spatial scales. Using these filters as a conceptual framework can help frame future research needed to elucidate processes of community assembly in urban areas. Understanding how humans influence community structure and processes will aid in the management, design, and planning of our cities to best support biodiversity.

Instagram Use, Loneliness, and Social Comparison Orientation: Interact and Browse on Social Media, But Don't Compare

Abstract: Ever since the emergence of social networking sites (SNSs), it has remained a question without a conclusive answer whether SNSs make people more or less lonely. To achieve a better understanding, researchers need to move beyond studying overall SNS usage. In addition, it is necessary to attend to personal attributes as potential moderators. Given that SNSs provide rich opportunities for social comparison, one highly relevant personality trait would be social comparison orientation (SCO), and yet this personal attribute has been understudied in social media research. Drawing on literature of psychosocial implications of social media use and SCO, this study explored associations between loneliness and various Instagram activities and the role of SCO in this context. A total of 208 undergraduate students attending a U.S. mid-southern university completed a self-report survey (Mage = 19.43, SD = 1.35; 78 percent female; 57 percent White). Findings showed that Instagram interaction and Instagram brows...

Genome of the Asian longhorned beetle (Anoplophora glabripennis), a globally significant invasive species, reveals key functional and evolutionary innovations at the beetle–plant interface

Abstract: Relatively little is known about the genomic basis and evolution of wood-feeding in beetles. We undertook genome sequencing and annotation, gene expression assays, studies of plant cell wall degrading enzymes, and other functional and comparative studies of the Asian longhorned beetle, Anoplophora glabripennis, a globally significant invasive species capable of inflicting severe feeding damage on many important tree species. Complementary studies of genes encoding enzymes involved in digestion of woody plant tissues or detoxification of plant allelochemicals were undertaken with the genomes of 14 additional insects, including the newly sequenced emerald ash borer and bull-headed dung beetle. The Asian longhorned beetle genome encodes a uniquely diverse arsenal of enzymes that can degrade the main polysaccharide networks in plant cell walls, detoxify plant allelochemicals, and otherwise facilitate feeding on woody plants. It has the metabolic plasticity needed to feed on diverse plant species, contributing to its highly invasive nature. Large expansions of chemosensory genes involved in the reception of pheromones and plant kairomones are consistent with the complexity of chemical cues it uses to find host plants and mates. Amplification and functional divergence of genes associated with specialized feeding on plants, including genes originally obtained via horizontal gene transfer from fungi and bacteria, contributed to the addition, expansion, and enhancement of the metabolic repertoire of the Asian longhorned beetle, certain other phytophagous beetles, and to a lesser degree, other phytophagous insects. Our results thus begin to establish a genomic basis for the evolutionary success of beetles on plants.

Automatic microseismic denoising and onset detection using the synchrosqueezed continuous wavelet transform

Abstract: Typical microseismic data recorded by surface arrays are characterized by low signal-to-noise ratios (S/Ns) and highly nonstationary noise that make it difficult to detect small events. Currently, array or crosscorrelation-based approaches are used to enhance the S/N prior to processing. We have developed an alternative approach for S/N improvement and simultaneous detection of microseismic events. The proposed method is based on the synchrosqueezed continuous wavelet transform (SS-CWT) and custom thresholding of single-channel data. The SS-CWT allows for the adaptive filtering of time- and frequency-varying noise as well as offering an improvement in resolution over the conventional wavelet transform. Simultaneously, the algorithm incorporates a detection procedure that uses the thresholded wavelet coefficients and detects an arrival as a local maxima in a characteristic function. The algorithm was tested using a synthetic signal and field microseismic data, and our results have been compared wit...

Online Self-Presentation on Facebook and Self Development During the College Transition

Abstract: Self-presentation, a central element of young people’s identity development, now extends from face-to-face contexts to social networking sites. Online self-presentation may change when youth transition to college, faced with the need to reclaim or redefine themselves in the new environment. Drawing on theories of self-presentation and self development, this study explores changes in youth’s online self-presentation during their transition to a residential college. It also examines associations between online self-presentation and students’ self-esteem and self-concept clarity. We surveyed 218 college freshmen (M age = 18.07; 64 % female, 79 % White) at the beginning and again at the end of their first semester. Freshmen’s Facebook self-presentation became less restricted later in the semester. Broad, deep, positive, and authentic Facebook self-presentation was positively associated with perceived support from the audience, which contributed to higher self-esteem contemporaneously, though not longitudinally. Intentional Facebook self-presentation engaged students in self-reflection, which was related to lower self-concept clarity concurrently but higher self-esteem longitudinally. Findings clarified the paths from multifaceted online self-presentation to self development via interpersonal and intrapersonal processes during college transition.

Privacy and Security in Mobile Health: A Research Agenda

Abstract: Mobile health technology has great potential to increase healthcare quality, expand access to services, reduce costs, and improve personal wellness and public health. However, mHealth also raises significant privacy and security challenges.

Hybrid Seismic Denoising Using Higher-Order Statistics and Improved Wavelet Block Thresholding

Abstract: We introduce a nondiagonal seismic denoising method based on the continuous wavelet transform with hybrid block thresholding (BT). Parameters for the BT step are adaptively adjusted to the inferred signal property by minimizing the unbiased risk estimate of Stein (1980). The efficiency of the denoising for seismic data has been improved by adapting the wavelet thresholding and adding a preprocessing step based on a higher‐order statistical analysis and a postprocessing step based on Wiener filtering. Application of the proposed method on synthetic and real seismic data shows the effectiveness of the method for denoising and improving the signal‐to‐noise ratio of local microseismic, regional, and ocean bottom seismic data.

The National Veteran Sleep Disorder Study: Descriptive Epidemiology and Secular Trends, 2000-2010.

Abstract: STUDY OBJECTIVES: A large proportion of individuals affected by sleep disorders are untreated and susceptible to accidents, injuries, long-term sequelae (e.g., risk of cardiovascular disease, cancer, psychiatric disorders), and increased mortality risk. Few studies have examined the scope and magnitude of sleep disorder diagnoses in the United States (US) or factors influencing them. Veterans are particularly vulnerable to factors that elicit or exacerbate sleep disorders. METHODS: This serial cross-sectional study characterized secular trends in diagnosed sleep disorders among veterans seeking care in US Veterans Health Administration facilities over an eleven-year span (FY2000-2010, N = 9,798,034). Electronic medical records from the national Veterans Administration Informatics and Computing Infrastructure database were accessed. Cases were defined using diagnostic codes specified by the American Academy of Sleep Medicine. Age-adjusted annual prevalence was summarized by sex, race, combat exposure, body mass index, and comorbid diagnoses (cardiovascular disease, cancer, mental disorders). RESULTS: Sleep apnea (47%) and insomnia (26%) were the most common diagnoses among patients with any sleep disorder. There was a six-fold relative increase in total sleep disorder prevalence over the study period. Post-traumatic stress disorder, which tripled over the same time period, was associated with the highest prevalence of sleep disorders (16%) among the comorbid conditions evaluated. CONCLUSIONS: The results indicate a growing need for integration of sleep disorder management with patient care and health care planning among US veterans.Copyright © 2016 Associated Professional Sleep Societies, LLC. All rights reserved. Language: en

Fundamental movement skills and physical fitness as predictors of physical activity: A 6-year follow-up study

Abstract: The purpose of this study was to examine the extent to which fundamental movement skills and physical fitness scores assessed in early adolescence predict self-reported physical activity assessed 6 years later. The sample comprised 333 (200 girls, 133 boys; M age = 12.41) students. The effects of previous physical activity, sex, and body mass index (BMI) were controlled in the main analyses. Adolescents’ fundamental movement skills, physical fitness, self-report physical activity, and BMI were collected at baseline, and their self-report energy expenditure (metabolic equivalents: METs) and intensity of physical activity were collected using the International Physical Activity Questionnaire 6 years later. Results showed that fundamental movement skills predicted METs, light, moderate, and vigorous intensity physical activity levels, whereas fitness predicted METs, moderate, and vigorous physical activity levels. Hierarchical regression analyses also showed that after controlling for previous levels of physical activity, sex, and BMI, the size of the effect of fundamental movement skills and physical fitness on energy expenditure and physical activity intensity was moderate (R2 change between 0.06 and 0.15), with the effect being stronger for high intensity physical activity.

Conversations with AutoTutor Help Students Learn

Abstract: AutoTutor helps students learn by holding a conversation in natural language. AutoTutor is adaptive to the learners’ actions, verbal contributions, and in some systems their emotions. Many of AutoTutor’s conversation patterns simulate human tutoring, but other patterns implement ideal pedagogies that open the door to computer tutors eclipsing human tutors in learning gains. Indeed, current versions of AutoTutor yield learning gains on par with novice and expert human tutors. This article selectively highlights the status of AutoTutor’s dialogue moves, learning gains, implementation challenges, differences between human and ideal tutors, and some of the systems that evolved from AutoTutor. Current and future AutoTutor projects are investigating three-party conversations, called trialogues, where two agents (such as a tutor and student) interact with the human learner.

Developmental variations in the impact of intimate partner violence exposure during childhood.

Abstract: BACKGROUND: Intimate partner violence (IPV) is a pervasive problem impacting individuals around the globe. The consequences of IPV extend beyond the adults in the relationship, as children witness a significant proportion of such violence. Exposure to IPV during childhood has devastating effects across multiple domains of functioning. METHODS: This article reviews empirical studies of the effects of exposure to IPV by developmental stage. RESULTS: The psychological, social, physical, and cognitive consequences of witnessing IPV are examined across development; from the impact of prenatal exposure to effects in infancy and toddlerhood, the preschool years, school-aged children, and adolescence. CONCLUSIONS: The review concludes by providing suggestions for future research based on the identified developmental variations, recommendations for developmentally-sensitive interventions for children who have witnessed IPV, and directions for policy to address the issue of violence exposure early in the lives of children. Language: en

Ancestral Gene Flow and Parallel Organellar Genome Capture Result in Extreme Phylogenomic Discord in a Lineage of Angiosperms.

Abstract: While hybridization has recently received a resurgence of attention from systematists and evolutionary biologists, there remains a dearth of case studies on ancient, diversified hybrid lineages-clades of organisms that originated through reticulation. Studies on these groups are valuable in that they would speak to the long-term phylogenetic success of lineages following gene flow between species. We present a phylogenomic view of Heuchera, long known for frequent hybridization, incorporating all three independent genomes: targeted nuclear (~400,000 bp), plastid (~160,000 bp), and mitochondrial (~470,000 bp) data. We analyze these data using multiple concatenation and coalescence strategies. The nuclear phylogeny is consistent with previous work and with morphology, confidently suggesting a monophyletic Heuchera. By contrast, analyses of both organellar genomes recover a grossly polyphyletic Heuchera,consisting of three primary clades with relationships extensively rearranged within these as well. A minority of nuclear loci also exhibit phylogenetic discord; yet these topologies remarkably never resemble the pattern of organellar loci and largely present low levels of discord inter alia. Two independent estimates of the coalescent branch length of the ancestor of Heuchera using nuclear data suggest rare or nonexistent incomplete lineage sorting with related clades, inconsistent with the observed gross polyphyly of organellar genomes (confirmed by simulation of gene trees under the coalescent). These observations, in combination with previous work, strongly suggest hybridization as the cause of this phylogenetic discord. [Ancient hybridization; chloroplast capture; incongruence; phylogenomics; reticulation.].

Use of Mobile Health Applications for Health-Seeking Behavior Among US Adults

Abstract: This study explores the use of mobile health applications (mHealth apps) on smartphones or tablets for health-seeking behavior among US adults. Data was obtained from cycle 4 of the 4th edition of the Health Information National Trends Survey (HINTS 4). Weighted multivariate logistic regression models examined predictors of 1) having mHealth apps, 2) usefulness of mHealth apps in achieving health behavior goals, 3) helpfulness in medical care decision-making, and 4) asking a physician new questions or seeking a second opinion. Using the Andersen Model of health services utilization, independent variables of interest were grouped under predisposing factors (age, gender, race, ethnicity, and marital status), enabling factors (education, employment, income, regular provider, health insurance, and rural/urban location of residence), and need factors (general health, confidence in their ability to take care of health, Body Mass Index, smoking status, and number of comorbidities). In a national sample of adults who had smartphones or tablets, 36 % had mHealth apps on their devices. Among those with apps, 60 % reported the usefulness of mHealth apps in achieving health behavior goals, 35 % reported their helpfulness for medical care decision-making, and 38 % reported their usefulness in asking their physicians new questions or seeking a second opinion. The multivariate models revealed that respondents were more likely to have mHealth apps if they had more education, health insurance, were confident in their ability to take good care of themselves, or had comorbidities, and were less likely to have them if they were older, had higher income, or lived in rural areas. In terms of usefulness of mHealth apps, those who were older and had higher income were less likely to report their usefulness in achieving health behavior goals. Those who were older, African American, and had confidence in their ability to take care of their health were more likely to respond that the mHealth apps were helpful in making a medical care decision and asking their physicians new questions or for a second opinion. Potentially, mHealth apps may reduce the burden on primary care, reduce costs, and improve the quality of care. However, several personal-level factors were associated with having mHealth apps and their perceived helpfulness among their users, indicating a multidimensional digital divide in the population of US adults.