Showing papers by "University of Memphis published in 2011"

Complicated grief and related bereavement issues for DSM‐5

Abstract: Bereavement is a severe stressor that typically incites painful and debilitating symptoms of acute grief that commonly progresses to restoration of a satisfactory, if changed, life. Normally, grief does not need clinical intervention. However, sometimes acute grief can gain a foothold and become a chronic debilitating condition called complicated grief. Moreover, the stress caused by bereavement, like other stressors, can increase the likelihood of onset or worsening of other physical or mental disorders. Hence, some bereaved people need to be diagnosed and treated. A clinician evaluating a bereaved person is at risk for both over-and under-diagnosis, either pathologizing a normal condition or neglecting to treat an impairing disorder. The authors of DSM IV focused primarily on the problem of over-diagnosis, and omitted complicated grief because of insufficient evidence. We revisit bereavement considerations in light of new research findings. This article focuses primarily on a discussion of possible inclusion of a new diagnosis and dimensional assessment of complicated grief. We also discuss modifications in the bereavement V code and refinement of bereavement exclusions in major depression and other disorders.

Election Night’s Alright for Fighting: The Role of Emotions in Political Participation

Abstract: A large literature has established a persistent association between the skills and resources citizens possess and their likelihood of participating in politics. However, the short-term motivational forces that cause citizens to employ those skills and expend resources in one election but not the next have only recently received attention. Findings in political psychology suggest specific emotions may play an important role in mobilization, but the question of “which emotions play what role?” remains an important area of debate. Drawing on cognitive appraisal theory and the Affective Intelligence model, we predict that anger, more than anxiety or enthusiasm, will mobilize. We find evidence for the distinctive influence of anger in a randomized experiment, a national survey of the 2008 electorate, and in pooled American National Election Studies from 1980 to 2004.

Green marketing strategies: an examination of stakeholders and the opportunities they present

Abstract: As green marketing strategies become increasingly more important to firms adhering to a triple-bottom line performance evaluation, the present research seeks to better understand the role of “green” as a marketing strategy. Through an integration of the marketing, management, and operations literatures, an investigative framework is generated that identifies the various stakeholders potentially impacted through the environmentally friendly efforts of a firm. Specifically, the inter-connected nature of the core business disciplines of marketing, management (both strategy and human resources), and operations are examined as controllable functions within an organization from which strategies can be enacted to affect a firm’s stakeholders. The prior research in these areas is examined to identify potential research opportunities in marketing while also offering a series of representative research questions that can help guide future research in marketing.

Coh-Metrix: Providing Multilevel Analyses of Text Characteristics

Abstract: Computer analyses of text characteristics are often used by reading teachers, researchers, and policy makers when selecting texts for students. The authors of this article identify components of language, discourse, and cognition that underlie traditional automated metrics of text difficulty and their new Coh-Metrix system. Coh-Metrix analyzes texts on multiple measures of language and discourse that are aligned with multilevel theoretical frameworks of comprehension. The authors discuss five major factors that account for most of the variance in texts across grade levels and text categories: word concreteness, syntactic simplicity, referential cohesion, causal cohesion, and narrativity. They consider the importance of both quantitative and qualitative characteristics of texts for assigning the right text to the right student at the right time.

Plasmonic photo-thermal therapy (PPTT)

Abstract: Photo-thermal therapy (PTT) is a minimally-invasive therapy in which photon energy is converted into heat to kill cancer. Gold nanoparticles absorb light strongly and convert photon energy into heat quickly and efficiently, thereby making them superior contrast agents for PTT. This gold nanoparticle-assisted PTT called PPTT has showed great popularity and success in recent years. The present review starts with the outline of optical properties that base PPTT followed by description of the synthesis of several gold-based nanoparticles that have been used in PPTT including gold nanospheres, gold nanoshells, gold nanorods and gold nanocages. Therapeutic outcomes will be discussed for each type of gold nanoparticles. Cell death mechanisms and future perspectives of PPTT will be briefly mentioned at the end.

Review Article: Recent Advances in Artificial Immune Systems: Models and Applications

Abstract: The immune system is a remarkable information processing and self learning system that offers inspiration to build artificial immune system (AIS). The field of AIS has obtained a significant degree of success as a branch of Computational Intelligence since it emerged in the 1990s. This paper surveys the major works in the AIS field, in particular, it explores up-to-date advances in applied AIS during the last few years. This survey has revealed that recent research is centered on four major AIS algorithms: (1) negative selection algorithms; (2) artificial immune networks; (3) clonal selection algorithms; (4) Danger Theory and dendritic cell algorithms. However, other aspects of the biological immune system are motivating computer scientists and engineers to develop new models and problem solving methods. Though an extensive amount of AIS applications has been developed, the success of these applications is still limited by the lack of any exemplars that really stand out as killer AIS applications.

The 2010 Mw 8.8 Maule megathrust earthquake of Central Chile, monitored by GPS.

Abstract: Large earthquakes produce crustal deformation that can be quantified by geodetic measurements, allowing for the determination of the slip distribution on the fault. We used data from Global Positioning System (GPS) networks in Central Chile to infer the static deformation and the kinematics of the 2010 moment magnitude ( M w) 8.8 Maule megathrust earthquake. From elastic modeling, we found a total rupture length of ~500 kilometers where slip (up to 15 meters) concentrated on two main asperities situated on both sides of the epicenter. We found that rupture reached shallow depths, probably extending up to the trench. Resolvable afterslip occurred in regions of low coseismic slip. The low-frequency hypocenter is relocated 40 kilometers southwest of initial estimates. Rupture propagated bilaterally at about 3.1 kilometers per second, with possible but not fully resolved velocity variations.

Hand in motion reveals mind in motion.

Abstract: Recently, researchers have measured hand movements en route to choices on a screen to understand the dynamics of a broad range of psychological processes. We review this growing body of research and explain how manual action exposes the real-time unfolding of underlying cognitive processing. We describe how simple hand motions may be used to continuously index participants’ tentative commitments to different choice alternatives during the evolution of a behavioral response. As such, hand-tracking can provide unusually high-fidelity, real-time motor traces of the mind. These motor traces cast novel theoretical and empirical light onto a wide range of phenomena and serve as a potential bridge between far-reaching areas of psychological science—from language, to high-level cognition and learning, to social cognitive processes.

Computational Analyses of Multilevel Discourse Comprehension

Abstract: The proposed multilevel framework of discourse comprehension includes the surface code, the textbase, the situation model, the genre and rhetorical structure, and the pragmatic communication level. We describe these five levels when comprehension succeeds and also when there are communication misalignments and comprehension breakdowns. A computer tool has been developed, called Coh-Metrix, that scales discourse (oral or print) on dozens of measures associated with the first four discourse levels. The measurement of these levels with an automated tool helps researchers track and better understand multilevel discourse comprehension. Two sets of analyses illustrate the utility of Coh-Metrix in discourse theory and educational practice. First, Coh-Metrix was used to measure the cohesion of the text base and situation model, as well as potential extraneous variables, in a sample of published studies that manipulated text cohesion. This analysis helped us better understand what was precisely manipulated in these studies and the implications for discourse comprehension mechanisms. Second, Coh-Metrix analyses are reported for samples of narrative and science texts in order to advance the argument that traditional text difficulty measures are limited because they fail to accommodate most of the levels of the multilevel discourse comprehension framework.

Continuous inference of psychological stress from sensory measurements collected in the natural environment

Abstract: Repeated exposures to psychological stress can lead to or worsen diseases of slow accumulation such as heart diseases and cancer. The main challenge in addressing the growing epidemic of stress is a lack of robust methods to measure a person's exposure to stress in the natural environment. Periodic self-reports collect only subjective aspects, often miss stress episodes, and impose significant burden on subjects. Physiological sensors provide objective and continuous measures of stress response, but exhibit wide between-person differences and are easily confounded by daily activities (e.g., speaking, physical movements, coffee intake, etc.). In this paper, we propose, train, and test two models for continuous prediction of stress from physiological measurements captured by unobtrusive, wearable sensors. The first model is a physiological classifier that predicts whether changes in physiology represent stress. Since the effect of stress may persist in the mind longer than its acute effect on physiology, we propose a perceived stress model to predict perception of stress. It uses the output of the physiological classifier to model the accumulation and gradual decay of stress in the mind. To account for wide between-person differences, both models self-calibrate to each subject. Both models were trained using data collected from 21 subjects in a lab study, where they were exposed to cognitive, physical, and social stressors representative of that experienced in the natural environment. Our physiological classifier achieves 90% accuracy and our perceived stress model achieves a median correlation of 0.72 with self-reported rating. We also evaluate the perceived stress model on data collected from 17 participants in a two-day field study, and find that the average rating of stress obtained from our model has a correlation of 0.71 with that obtained from periodic self-reports.

Deacetylation of Chitosan: Material Characterization and in vitro Evaluation via Albumin Adsorption and Pre-Osteoblastic Cell Cultures

Abstract: Degree of deacetylation (DDA) and molecular weight (MW) of chitosans are important to their physical and biological properties. In this study, two chitosans, HS (DDA = 73.3%) and AT (DDA = 76.8%), were deacetylated with 45% sodium hydroxide under nitrogen atmosphere at 80 °C or 90 °C for up to 120 min, to obtain two series of chitosans. The polymers produced were characterized for MW by gel permeation chromatography, DDA by titration and UV-vis methods, and crystallinity, hydrophilicity and thermal stability by X-ray diffraction, water contact angle and differential scanning calorimetry respectively. Films, made by solution casting in dilute acetic acid at ambient conditions, were evaluated for biological activity by albumin adsorption and the attachment and growth of a pre-osteoblast cell line. Chitosans with between 80–93% DDA’s (based on titration) were reproducibly obtained. Even though deacetylation under nitrogen was supposed to limit chain degradation during decetylation, MW decreased (by maximum of 37.4% of HS and 63.0% for AT) with increasing deacetylation reaction time and temperature. Crystallinity and decomposition temperature increased and water contact angles decreased with processing to increase DDA. Significantly less albumin was absorbed on films made with 93% DDA chitosans as compared with the original materials and the AT chitosans absorbed less than the HS chitosans. The cells on higher DDA chitosan films grew faster than those on lower DDA films. In conclusion, processing conditions increased DDA and influenced physicochemical and biological properties. However, additional studies are needed to unambiguously determine the influence of DDA or MW on in vitro and in vivo performance of chitosan materials for bone/implant applications.

Symbol interdependency in symbolic and embodied cognition.

Abstract: Whether computational algorithms such as latent semantic analysis (LSA) can both extract meaning from language and advance theories of human cognition has become a topic of debate in cognitive science, whereby accounts of symbolic cognition and embodied cognition are often contrasted. Albeit for different reasons, in both accounts the importance of statistical regularities in linguistic surface structure tends to be underestimated. The current article gives an overview of the symbolic and embodied cognition accounts and shows how meaning induction attributed to a specific statistical process or to activation of embodied representations should be attributed to language itself. Specifically, the performance of LSA can be attributed to the linguistic surface structure, more than special characteristics of the algorithm, and embodiment findings attributed to perceptual simulations can be explained by distributional linguistic information.

AutoSense: unobtrusively wearable sensor suite for inferring the onset, causality, and consequences of stress in the field

Abstract: The effect of psychosocial stress on health has been a central focus area of public health research. However, progress has been limited due a to lack of wearable sensors that can provide robust measures of stress in the field. In this paper, we present a wireless sensor suite called AutoSense that collects and processes cardiovascular, respiratory, and thermoregularity measurements that can inform about the general stress state of test subjects in their natural environment. AutoSense overcomes several challenges in the design of wearable sensor systems for use in the field. First, it is unobtrusively wearable because it integrates six sensors in a small form factor. Second, it demonstrates a low power design; with a lifetime exceeding ten days while continuously sampling and transmitting sensor measurements. Third, sensor measurements are robust to several sources of errors and confounds inherent in field usage. Fourth, it integrates an ANT radio for low power and integrated quality of service guarantees, even in crowded environments. The AutoSense suite is complemented with a software framework on a smart phone that processes sensor measurements received from AutoSense to infer stress and other rich human behaviors. AutoSense was used in a 20+ subject real-life scientific study on stress in both the lab and field, which resulted in the first model of stress that provides 90% accuracy.

Debunking Myths and Urban Legends About Meta-Analysis

Abstract: Meta-analysis is the dominant approach to research synthesis in the organizational sciences. We discuss seven meta-analytic practices, misconceptions, claims, and assumptions that have reached the status of myths and urban legends (MULs). These seven MULs include issues related to data collection (e.g., consequences of choices made in the process of gathering primary-level studies to be included in a meta-analysis), data analysis (e.g., effects of meta-analytic choices and technical refinements on substantive conclusions and recommendations for practice), and the interpretation of results (e.g., meta-analytic inferences about causal relationships). We provide a critical analysis of each of these seven MULs, including a discussion of why each merits being classified as an MUL, their kernels of truth value, and what part of each MUL represents misunderstanding. As a consequence of discussing each of these seven MULs, we offer best-practice recommendations regarding how to conduct meta-analytic reviews.

Impact of caloric and dietary restriction regimens on markers of health and longevity in humans and animals: a summary of available findings

Abstract: Considerable interest has been shown in the ability of caloric restriction (CR) to improve multiple parameters of health and to extend lifespan. CR is the reduction of caloric intake - typically by 20 - 40% of ad libitum consumption - while maintaining adequate nutrient intake. Several alternatives to CR exist. CR combined with exercise (CE) consists of both decreased caloric intake and increased caloric expenditure. Alternate-day fasting (ADF) consists of two interchanging days; one day, subjects may consume food ad libitum (sometimes equaling twice the normal intake); on the other day, food is reduced or withheld altogether. Dietary restriction (DR) - restriction of one or more components of intake (typically macronutrients) with minimal to no reduction in total caloric intake - is another alternative to CR. Many religions incorporate one or more forms of food restriction. The following religious fasting periods are featured in this review: 1) Islamic Ramadan; 2) the three principal fasting periods of Greek Orthodox Christianity (Nativity, Lent, and the Assumption); and 3) the Biblical-based Daniel Fast. This review provides a summary of the current state of knowledge related to CR and DR. A specific section is provided that illustrates related work pertaining to religious forms of food restriction. Where available, studies involving both humans and animals are presented. The review includes suggestions for future research pertaining to the topics of discussion.

Service Worker Burnout and Turnover Intentions: Roles of Person-Job Fit, Servant Leadership, and Customer Orientation

Abstract: This study examines the effects of customer orientation and servant leadership on frontline employees' burnout and, subsequently, on their turnover intentions. Also investigated in the study is the intervening role of person-job fit in the process. Data collected from 530 frontline bank employees in New Zealand serve as the study setting. Results show that both customer orientation and servant leadership significantly reduce burnout and ultimately turnover intentions. Results also show that person-job fit mediates the influences of customer orientation and servant leadership on burnout and turnover intentions. Implications of the results are discussed and future research avenues are offered.

The half-life of cognitive-affective states during complex learning

Abstract: We investigated the temporal dynamics of students' cognitive-affective states (confusion, frustration, boredom, engagement/flow, delight, and surprise) during deep learning activities. After a learning session with an intelligent tutoring system with conversational dialogue, the cognitive-affective states of the learner were classified by the learner, a peer, and two trained judges at approximately 100 points in the tutorial session. Decay rates for the cognitive-affective states were estimated by fitting exponential curves to time series of affect responses. The results partially confirmed predictions of goal-appraisal theories of emotion by supporting a tripartite classification of the states along a temporal dimension: persistent states (boredom, engagement/flow, and confusion), transitory states (delight and surprise), and an intermediate state (frustration). Patterns of decay rates were generally consistent across affect judges, except that a reversed actor-observer effect was discovered for engagement/flow and frustration. Correlations between decay rates of the cognitive-affective states and several learning measures confirmed the major predictions and uncovered some novel findings that have implications for theories of pedagogy that integrate cognition and affect during deep learning.

Supply chain disruption risk management through strategic information acquisition and sharing and risk-sharing contracts

Abstract: In this paper, we develop a framework that captures the effects of information management and risk-sharing contracts in supply chain networks. In particular, we analyse the impact of strategic information acquisition and sharing on supply chain disruption risks and costs and we evaluate the supply chain performance of risk-sharing contracts. Risk-sharing contracts specify who needs to incur the costs when supply chain disruptions occur. We develop a model that consists of three tiers of multi-criteria decision-makers, manufacturers, retailers, and demand markets. We describe the behaviour or each decision-maker, derive the finite-dimensional variational inequality formulation of the equilibrium conditions of the supply chain and present numerical examples. The numerical examples highlight that it is not a priori clear which participant in the supply chain network will benefit from increased information-sharing activities. Our models indicate that the beneficiary of reduced information-sharing costs is in ...

The Public Health Implications of Consumers' Environmental Concern and Their Willingness to Pay for an Eco-Friendly Product

Abstract: Environmental concern has been an important topic for more than 40 years and has recently become even more critical with today's concerns about creating a sustainable and healthy environment. This research examines factors affecting an individual's willingness to pay more for an environmentally friendly product. Our results show that willingness to pay more differs across demographic groups. We also find that individuals who rate concern for waste as highly important are willing to spend more money on an eco-friendly product. Consequently, our findings provide insight into the development of appropriate educational strategies for different consumer groups to encourage consumers to purchase eco-friendly products, with a goal of creating a healthier environment for current and future generations. ********** The challenge of healthier communities begins with environmental concern and collective adoption of eco-friendly behaviors, because the choices consumers make with regard to the environment influence the health and quality of life for both current and future generations. In general terms, environmental concern is a "concept that can refer to feelings [consumers have] about many different green issues" (Zimmer, Stafford, and Stafford 1994, p. 64). The topic became an important one in 1962 when Rachel Carson's Silent Spring was published and has recently become even more critical with today's concerns about creating a sustainable and healthy environment. Trends show a remarkable increase in consumer worry about environmental problems (e.g., Gallup Poll 2009) and continued support for alternative forms of energy generation (Pew 2010) and other sustainable initiatives. Interest in environmental issues has also triggered rapid growth and enrollment in environmental courses offered in colleges and universities (Fuller 2010). In the corporate world, environmentalism has moved to the boardroom (Hanas 2007), while at the lay level, magazines such as Popular Mechanics feature articles related to global warming (http://www.popularmechanics.com 2010). In addition, a recent blog points out that popular media incorporate environmental messages into their programming: "The powers that be at NBC Universal started going green and making the environment a priority, using a tactic called 'behavior placement' to weave subtle eco-friendly messages into the scripts of some of the network's most popular daytime and prime time programs" (http://www.environment.about.com 2010). Although the environmental movement can be traced back to the nineteenth century, the modern iteration of environmental concern as an issue of critical interest began about four decades ago. Most recently, this concern has reappeared in the academic, scientific and popular press in terms of issues related to sustainability and renewable resources (e.g., Gallup 2009; Pew 2009, 2010). For example, a major initiative in the National Science Foundation's proposed 2011 budget is expanded support for climate research activities, designed to address challenges in sustainability, energy research and education (http://www.nsf.gov 2010). The latest approach to understanding and researching sustainability and environmental concepts spans several disciplines including marketing, public policy and public health, among others. In particular, sustainability is recognized as a major public health issue of the twenty-first century (American Public Health Association 2007). Health concerns are a primary component of overall environmental concern because physical surroundings (air quality, water protection and even the availability of health care alternatives) directly affect human survival and quality of life (Zimmer, Stafford, and Stafford 1994), and individuals who practice environmental behaviors will promote healthier communities, via improved quality of air, water and physical health (Patz and Olson 2006). Consequently, understanding environmental concern among consumers can have an important influence on public health. …

Privacy risks emerging from the adoption of innocuous wearable sensors in the mobile environment

Abstract: Wearable sensors are revolutionizing healthcare and science by enabling capture of physiological, psychological, and behavioral measurements in natural environments. However, these seemingly innocuous measurements can be used to infer potentially private behaviors such as stress, conversation, smoking, drinking, illicit drug usage, and others. We conducted a study to assess how concerned people are about disclosure of a variety of behaviors and contexts that are embedded in wearable sensor data. Our results show participants are most concerned about disclosures of conversation episodes and stress - inferences that are not yet widely publicized. These concerns are mediated by temporal and physical context associated with the data and the participant's personal stake in the data. Our results provide key guidance on the extent to which people understand the potential for harm and data characteristics researchers should focus on to reduce the perceived harm from such datasets.

Using a differential emission measure and density measurements in an active region core to test a steady heating model

Abstract: The frequency of heating events in the corona is an important constraint on the coronal heating mechanisms. Observations indicate that the intensities and velocities measured in active region cores are effectively steady, suggesting that heating events occur rapidly enough to keep high-temperature active region loops close to equilibrium. In this paper, we couple observations of active region (AR) 10955 made with the X-Ray Telescope and the EUV Imaging Spectrometer on board Hinode to test a simple steady heating model. First we calculate the differential emission measure (DEM) of the apex region of the loops in the active region core. We find the DEM to be broad and peaked around 3 MK. We then determine the densities in the corresponding footpoint regions. Using potential field extrapolations to approximate the loop lengths and the density-sensitive line ratios to infer the magnitude of the heating, we build a steady heating model for the active region core and find that we can match the general properties of the observed DEM for the temperature range of 6.3 < log T < 6.7. This model, for the first time, accounts for the base pressure, loop length, and distribution of apex temperatures of the core loops. Wemore » find that the density-sensitive spectral line intensities and the bulk of the hot emission in the active region core are consistent with steady heating. We also find, however, that the steady heating model cannot address the emission observed at lower temperatures. This emission may be due to foreground or background structures, or may indicate that the heating in the core is more complicated. Different heating scenarios must be tested to determine if they have the same level of agreement.« less

The Development of Writing Proficiency as a Function of Grade Level: A Linguistic Analysis:

Abstract: In this study, a corpus of essays stratified by level (9th grade, 11th grade, and college freshman) are analyzed computationally to discriminate differences between the linguistic features produced...

Short- and long-term effects of developmental corticosterone exposure on avian physiology, behavioral phenotype, cogni- tion, and fitness: A review

Abstract: A growing body of evidence from across taxa suggests that exposure to elevated levels of glucocorticoids during early development can have long-term effects upon physiological and behavioral phenotypes. Additionally, there is some, though limited, evidence that similar early exposure can also negatively impact cognitive ability. Following pioneering mammalian stud- ies, several avian studies have revealed that the responsiveness of the hypothalamo-pituitary-adrenal (HPA) axis as an adult can be explained by levels of corticosterone, the avian glucocorticoid, the individual experienced as a nestling or even as an embryo via yolk exposure. Studies also suggest that perinatal exposure to corticosterone can have effects upon avian 'personalities' or coping styles, and findings from mammalian studies suggest that these long-term effects are mediated epigenetically via altered expression of relevant DNA sequences. Although a consistent pattern across-species has yet to emerge, recent work in Florida scrub-jays Aphelocoma coerulescens found that baseline corticosterone levels in 11-day-old nestlings explained 84% of the varia- tion in 'personality' (bold vs. timid) when those individuals were tested approximately seven months later. Nestlings with ele- vated corticosterone levels were more timid than those individuals that as nestlings experienced relatively low corticosterone lev- els. Some researchers have suggested that parents might use such mechanisms to 'program' their offsprings' phenotype to best fit prevailing environmental conditions. This review will visit what is known about the links between stressful developmental condi- tions that result in exposure to elevated corticosterone and the short- and long-term effects of this steroid hormone upon central nervous system function and whether alterations thereof are beneficial, deleterious, or neutral. It will concentrate on examples from birds, although critical supporting studies from the mammalian literature will be included as appropriate (Current Zoology 57 (4): 514-530, 2011).

A Survey of Minimum Saturated Graphs

Abstract: Given a family of (hyper)graphs $\mathcal{F}$ a (hyper)graph $G$ is said to be $\mathcal{F}$-saturated if $G$ is $F$-free for any $F \in\mathcal{F}$ but for any edge e in the complement of $G$ the (hyper)graph $G + e$ contains some $F\in\mathcal{F}$. We survey the problem of determining the minimum size of an $\mathcal{F}$-saturated (hyper)graph and collect many open problems and conjectures.