Self-consistent Modeling of the IcI_c of HTS Devices: How Accurate do Models Really Need to Be?

Numerical models for computing the effective critical current of devices made of HTS tapes require the knowledge of the Jc(B,theta) dependence, i.e. of the way the critical current density Jc depends on the magnetic flux density B and its orientation theta with respect to the tape. In this paper we present a numerical model based on the critical state with angular field dependence of Jc to extract the Jc(B,theta) relation from experimental data. The model takes into account the self-field created by the tape, which gives an important contribution when the field applied in the experiments is low. The same model can also be used to compute the effective critical current of devices composed of electromagnetically interacting tapes. Three examples are considered here: two differently current rated Roebel cables composed of REBCO coated conductors and a power cable prototype composed of Bi-2223 tapes. The critical currents computed with the numerical model show good agreement with the measured ones. The simulations reveal also that several parameter sets in the Jc(B,theta) give an equally good representation of the experimental characterization of the tapes and that the measured Ic values of cables are subjected to the influence of experimental conditions, such as Ic degradation due to the manufacturing and assembling process and non-uniformity of the tape properties. These two aspects make the determination of a very precise Jc(B,theta) expression probably unnecessary, as long as that expression is able to reproduce the main features of the angular dependence. The easiness of use of this model, which can be straightforwardly implemented in finite-element programs able to solve static electromagnetic problems, is very attractive both for researchers and devices manufactures who want to characterize superconducting tapes and calculate the effective critical current of superconducting devices

Nucleic Acid Sensing by the Immune System: Roles For the Receptor For Advanced Glycation End Products (RAGE) and Intracellular Receptor Proteins: A Dissertation

As humans, we inhabit an environment shared with many microorganisms, some of which are harmless or beneficial, and others which represent a threat to our health. A complex network of organs, cells and their protein products form our bodies’ immune system, tasked with detecting these potentially harmful agents and eliminating them. This same system also serves to detect changes in the healthy balance of normal functions in the body, and for repairing tissue damage caused by injury. Immune recognition of nucleic acids, DNA and RNA, is one way that the body detects invading pathogens and initiates tissue repair. A number of specialized receptor proteins have evolved to distinguish nucleic acids that represent “threats” from those involved in normal physiology. These proteins include members of the Toll-like receptor family and diverse types of cytosolic proteins, all of which reside within the confines of the cell. Few proteins on the cell surface have been clearly characterized to interact with nucleic acids in the extracellular environment. In this dissertation, I present collaborative work that identifies the receptor for advanced glycation end products (RAGE) as a cell surface receptor for nucleic acids and positions it as an important modulator of immune responses. Molecular dimers of RAGE interact with the sugar-phosphate backbones of nucleic acid ligands, allowing this receptor to recognize a variety of DNA and RNA molecules regardless of their nucleotide sequence. Expression of RAGE on cells promotes uptake of DNA and enhances subsequent responses that are dependent on the nucleic acid sensor Toll-like receptor 9. When mice deficient in RAGE are exposed to DNA in the lung, the predominant site of RAGE expression, they do not mount a typical early inflammatory response, suggesting that RAGE is important in generating immune responses to DNA in mammalian organisms. Further evidence suggests that RAGE interacts preferentially with multimolecular complexes that contain nucleic acids, and that these complexes may induce clustering of receptor dimers into larger multimeric structures. Taken together, the data reported here identify RAGE as an important cell surface receptor protein for nucleic acids, which is capable of modulating the intensity of immune responses to DNA and RNA. Understanding of and intervention in this recognition pathway hold therapeutic promise for diseases characterized by excessive responses to self nucleic acids, such as systemic lupus erythematosus, and for the pathology caused by chronic inflammatory responses to self and foreign nucleic acids

Is procrastination related to sleep quality? Testing an application of the procrastination-health model

Despite a growing body of research on the consequences of procrastination for health and well-being, there is little research focused on testing or explaining the potential links between procrastination and sleep quality. Using the procrastination-health model as our guiding conceptual lens, we addressed this gap by examining how and why trait procrastination may be linked to various dimensions of sleep quality across two student samples. In Study 1, procrastination was associated with feeling unrested, but not sleep disturbance frequency, in a sample of Greek undergraduate students (N = 141). In Study 2, bootstrapping analysis of the indirect effects of procrastination on an index of sleep quality through perceived stress in a sample of Canadian students (N = 339) was significant supporting an extended procrastination-health model view of how chronic self-regulation failure may compromise sleep quality. Given the potential for dynamic and reciprocal relations among procrastination, stress, and sleep quality suggested by the current and other research, the ways in which procrastination may contribute to and be influenced by poor sleep quality warrants further investigation

Loneliness and preferences for palatable foods: The role of coping

Loneliness is an important public health issue with consequences for health-related outcomes. Health-related behaviors is a proposed explanatory pathway. There is some evidence that loneliness influences eating behaviors, although the reasons for this have not been fully examined. In addition, how eating behaviors are conceptualised and the subsequent findings are often inconsistent. Across two studies, we aimed to address these issues by investigating whether loneliness is associated with preferences for palatable over healthy foods, and two possible explanatory pathways: negative affect and using palatable foods as a coping strategy. Study 1 (N = 361) used a within-subjects design to test whether chronic loneliness influenced palatable food preferences in a healthy versus palatable food choice task, and if negative affect and using palatable food to cope explained this preference. Study 2 (N = 163) aimed to replicate the dispositional-correlational associations from Study 1 and experimentally test whether situational loneliness influenced food preferences. In Study 1, the indirect effects of chronic loneliness on preferences for palatable foods was significant for coping motives, ab = 0.0923, SE = 0.0324, 95% CI = [0.0417, 0.1732], but not for negative affect, ab = 0.0035, SE = 0.0486, 95% CI = [-0.0928, 0.0986]. Findings from Study 2 mirrored those from Study 1 with significant indirect effects of loneliness on preferences for palatable foods through coping motives, ab = 0.1831, SE = 0.1027, 95% CI = [0.0338, 0.4680], but not depressive symptoms, ab = -0.1046, SE = 0.2438, 95% CI = [-0.5576, 0.4092]. The loneliness manipulation did not increase state loneliness. Together these findings make important and novel contributions to our understanding of the strategies that lonely people use to cope with the distress they experience, and further highlights susceptibility to eating palatable foods as a potential behavioral pathway linking loneliness to poor health outcomes

A meta‐analysis of coping strategies and psychological distress in rheumatoid arthritis

Purpose: Theory and research indicate that coping plays a central role in the experience of psychological distress in people with rheumatoid arthritis (RA). This study meta‐analysed the associations of adaptive and maladaptive coping strategies with psychological distress in people with RA to quantify and better understand the proposed differential relationships, as well as the factors that might influence these links. Methods: Searches of four databases identified eligible studies according to a pre‐registered protocol. Two random effects meta‐analyses examined the direction and magnitude of the links between adaptive coping (problem‐focused and emotional approach coping) and maladaptive coping (emotional avoidance and pre‐occupation coping) and psychological distress (stress, anxiety, and depression). Study quality was evaluated using a bespoke tool. Moderator analyses for sample characteristics and distress type were conducted. Results: Searches identified 16 eligible studies with 46 effects. Meta‐analysis of maladaptive coping and distress yielded a significant, medium sized association, k = 12, r = .347, 95% CIs [.23, .46]. Moderator analyses were significant only for type of distress, with effects for depression being larger than that for combined distress. Effects did not vary as a function of age, participant sex, or disease duration. Meta‐analysis for adaptive coping was not significant, k = 10, r = −.155, 95% CIs [−.31, .01]. Conclusions: Findings from this first meta‐analysis of coping and distress in RA indicate that maladaptive but not adaptive coping is associated with greater distress. Further research is needed to grow the evidence base to verify the current findings especially with respect to adaptive coping

Self-Compassion and Adherence in Five Medical Samples: the Role of Stress

Emerging evidence indicates self-compassion can be beneficial for medical populations and for medical adherence; yet, research to date has not fully examined the reasons for this association. This study examined the association of dispositional self-compassion to adherence across five medical samples and tested the extent to which perceived stress accounted for this association. Five medical samples (total N = 709), including fibromyalgia, chronic fatigue syndrome, and cancer patients, recruited from various sources, completed online surveys. Self-compassion was positively associated with adherence in all five samples. A meta-analysis of the associations revealed a small average effect size (average r = .22, [0.15, 0.29]) of self-compassion and adherence and non-significant heterogeneity among the effects (Q (4) = 3.15, p = .532). A meta-analysis of the kappa2 values from the indirect effects of self-compassion on adherence revealed that, on average, 11% of the variance in medical adherence that was explained by self-compassion could be attributed to lower perceived stress. Overall, findings demonstrate that dispositional self-compassion is associated with better medical adherence among people with fibromyalgia, chronic fatigue syndrome, and cancer, due in part to lower stress. This research contributes to a growing evidence base indicating the value of self-compassion for health-related behaviours in a variety of medical populations

Big Five traits, affect balance and health behaviors: A self-regulation resource perspective

Despite the relatively consistent finding that Conscientiousness, Agreeableness and low Neuroticism are associated with the practice of health-promoting behaviors, the reasons for these linkages are not well understood. This prospective study addressed this gap by taking a self-regulation resource perspective on why these traits relate to health-promoting behaviors by examining the role of higher positive relative to negative state affect. Students completed baseline (N = 330), and two week follow-up (N = 195) surveys. Bootstrapping analyses of the indirect effects of each of the three traits on Time 2 health behaviors were significant in the expected directions, with Kappa squares ranging from .11 to .13. In the full longitudinal analyses controlling for Time 1 health behaviors, the indirect effects of Conscientiousness and Agreeableness through affect balance on Time 2 health behaviors were positive and significant, whereas the indirect effects through Neuroticism were negative and significant after accounting for the Time 1 practice of health behaviors. These findings provide a process-oriented understanding of how Big Five traits are linked to health-promoting behaviors and extend previous research supporting a self-regulation resource perspective on personality and health behaviors

Self-Compassion and Adherence in Five Medical Samples: the Role of Stress

Emerging evidence indicates self-compassion can be beneficial for medical populations and for medical adherence; yet, research to date has not fully examined the reasons for this association. This study examined the association of dispositional self-compassion to adherence across five medical samples and tested the extent to which perceived stress accounted for this association. Five medical samples (total N = 709), including fibromyalgia, chronic fatigue syndrome, and cancer patients, recruited from various sources, completed online surveys. Self-compassion was positively associated with adherence in all five samples. A meta-analysis of the associations revealed a small average effect size (average r = .22, [0.15, 0.29]) of self-compassion and adherence and non-significant heterogeneity among the effects (Q (4) = 3.15, p = .532). A meta-analysis of the kappa2 values from the indirect effects of self-compassion on adherence revealed that, on average, 11% of the variance in medical adherence that was explained by self-compassion could be attributed to lower perceived stress. Overall, findings demonstrate that dispositional self-compassion is associated with better medical adherence among people with fibromyalgia, chronic fatigue syndrome, and cancer, due in part to lower stress. This research contributes to a growing evidence base indicating the value of self-compassion for health-related behaviours in a variety of medical populations