Integrin-based adhesions promote cell-cell junction and cytoskeletal remodelling to drive embryonic wound healing.

Embryos repair wounds rapidly, with no inflammation or scarring. Embryonic wound healing is driven by the collective movement of the cells around the lesion. The cells adjacent to the wound polarize the cytoskeletal protein actin and the molecular motor non-muscle myosin II, which accumulate at the wound edge forming a supracellular cable around the wound. Adherens junction proteins, including E-cadherin, are internalized from the wound edge and localize to former tricellular junctions at the wound margin, in a process necessary for cytoskeletal polarity. We found that the cells adjacent to wounds in the Drosophila embryonic epidermis polarized Talin, a core component of cell-extracellular matrix (ECM) adhesions, which preferentially accumulated at the wound edge. Integrin knockdown and inhibition of integrin binding delayed wound closure and reduced actin polarization and dynamics around the wound. Additionally, disrupting integrins caused a defect in E-cadherin reinforcement at tricellular junctions along the wound edge, suggesting crosstalk between integrin-based and cadherin-based adhesions. Our results show that cell-ECM adhesion contributes to embryonic wound repair and reveal an interplay between cell-cell and cell-ECM adhesion in the collective cell movements that drive rapid wound healing.

Sleep Disturbance and Its Association With Sluggish Cognitive Tempo and Attention in Pediatric Brain Tumor Survivors.

Background: Pediatric brain tumor (PBT) survivors are at risk for developing sleep disturbances. While in other pediatric populations sleep disturbance has been associated with worse cognitive functioning, it is unclear to what extent this relationship generalizes to PBT survivors. The aim of the current study was to assess the relationship between sleep disturbance and aspects of cognition, including sluggish cognitive tempo (SCT) as well as attention and working memory. Materials and Methods: Eighty-three PBT survivors 6-18 years of age who were at least 3 months post-treatment were included in the present cross-sectional study. Level of sleep disturbance was measured as a composite score reflecting various sleep problems as rated by caregivers. Cognitive measures included caregiver-ratings of sluggish cognitive tempo and attention problems, as well as performance-based cognitive measures assessing attention and executive functioning. Hierarchical regression analysis was used to assess associations between sleep and cognition. Results: Of all caregivers, 32.5% reported one or more sleep disturbances as "very/often true" and over 68% of caregivers rated at least one sleep-related item as "somewhat true." Of all cognitive variables, scores were most frequently impaired for SCT (30%). A higher level of sleep disturbance was associated with worse SCT and parent-rated attention problems. Associations between sleep and performance-based cognitive measures assessing attention and working memory were not statistically significant. Conclusion: Findings of the current study highlight the importance of further investigation into the relationship between sleep and cognition in PBT survivors, which may assist efforts to maximize cognitive outcome and health-related quality of life in PBT survivors. The current study additionally suggests further investigation of SCT in this population is warranted, as it may be more sensitive to detecting possible associations with sleep disturbance relative to discrete measures that assess cognitive performance under ideal circumstances.

Behavioral Capital Theory via Canonical Quantization.

We show how a behavioral form of capital theory can be derived using canonical quantization. In particular, we introduce quantum cognition into capital theory by applying Dirac's canonical quantization approach to Weitzman's Hamiltonian formulation of capital theory, the justification for the use of quantum cognition being the incompatibility of questions encountered in the investment decision-making process. We illustrate the utility of this approach by deriving the capital-investment commutator for a canonical dynamic investment problem.

Test of a clinical model of poor physical health and suicide: The role of depression, psychosocial stress, interpersonal conflict, and panic.

BACKGROUND: This study employed a structural equation model to examine the relationships between poor physical health, suicide, depression, psychosocial stress, interpersonal conflict, and panic. METHODS: The sample consisted of a large, archived set of mental health treatment-seeking adults who completed a behavioral outcome questionnaire prior to beginning treatment. RESULTS: Results supported the extant literature indicating that poor physical health, depression, psychosocial stress, interpersonal conflict, and panic impose increased risk for suicidal ideation, with depression demonstrating the highest risk for increased suicidal ideation. The results also supported the hypotheses that depression, psychosocial stress, interpersonal conflict, and panic would mediate the association between poor physical health and suicidal ideation. Although no a priori hypotheses were made regarding relationships among the 15 physical illnesses examined, results indicated that HIV/AIDS had the strongest correlation with depression and the weakest correlation with interpersonal conflict. LIMITATIONS: Firstly, the study sample was primarily Caucasian, limiting its generalizability. Secondly, causal inferences should be interpreted with caution, due to the quasi-experimental design. Thirdly, these data were self-reported, which create response biases since suicidal ideation is stigmatized. CONCLUSIONS: These findings highlight the importance of considering interpersonal factors as potential mediators in the relationship between poor physical health, mental illness, and suicide. Clinically, the impact of an active major depressive episode on an individual who is struggling with a serious physical illness may be strongly predictive of suicidal ideation.

Quantifying system order for full and partial coarse graining.

We show that Fisher information I and its weighted versions effectively measure the order R of a large class of shift-invariant physical systems. This result follows from the assumption that R decreases under small perturbations caused by a coarse graining of the system. The form found for R is generally unitless, which allows the order for different phenomena to be compared objectively. The monotonic contraction properties of R and I in time imply that they are entropies, in addition to their usual status as information. This removes the need for data, and therefore an observer, in physical derivations based upon their use. Thus, this recognizes complementary scenarios to the participatory observer of Wheeler, where (now) physical phenomena can occur in the absence of an observer. Simple applications of the new order measure R are discussed.

Substance abuse as a dynamical disease: evidence and clinical implications of nonlinearity in a time series of daily alcohol consumption.

Several authors have suggested that chaos theory, the study of nonlinear dynamics and the application of the knowledge gained to natural and social phenomena, might yield insight into substance-related disorders. In this article, we examine the dynamics of substance abuse by fitting a nonlinear model to a time series of the amount of alcohol, which an adult male with a diagnosis of substance abuse consumed on a daily basis. The nonlinear model shows a statistically superior fit when compared to a linear model. We then use the model to explore a question that is pertinent to the treatment of substance abuse, whether controlled drinking or abstinence is a preferred strategy for maintaining sobriety.

A Chlamydia trachomatis-specific Th2 clone does not provide protection against a genital infection and displays reduced trafficking to the infected genital mucosa.

A T helper type 1 (Th1) response is essential for resolving genital infections with the mouse pneumonitis biovar of Chlamydia trachomatis (MoPn). However, T-cell-dependent anti-chlamydial antibody is produced and may also contribute to protective immunity. We produced a MoPn-specific CD4 Th2 clone (Th2-MoPn) to study the role of a Th2 response during infection. We found that Th2-MoPn was unable to eradicate chlamydiae from the genital tract (GT) when it was transferred into MoPn-infected nude mice. Mice that received Th2-MoPn produced greater titers of MoPn-specific serum immunoglobulin G (IgG) antibody than mice that received a MoPn-specific Th1 clone (Th1-MoPn) (log(10) titers, 1.89 +/- 0.84 and 0.58 +/- 0.76 [mean +/- standard deviation], respectively [P < 0.01]). Also, the IgG isotypes were different for the two groups; whereas IgG1 was associated with Th2-MoPn, IgG2a was associated with Th1-MoPn. Also, infected nude mice that received Th2-MoPn produced higher levels of IgA in vaginal secretions. Although clone Th2-MoPn was detected in the GT, it was less efficient at migrating (112 +/- 35.6 labeled Th2 clone cells/10(5) GT cells) than Th1-MoPn (505 +/- 51.6 Th1 clone cells/10(5) GT cells) (P < 0.001, as determined by a t test). This may have been due to reduced expression of alpha4beta7 and P-selectin ligand 1 on Th2-MoPn. However, Th2-MoPn cells were retained in the GT during chronic infection and comprised 10 to 15% of the total GT cells 80 days after transfer. The data show that the MoPn-specific Th2 cells are important for serum and vaginal antibody production and may accumulate in the GT during chronic infection.

Multiscale nonlinearity in a time series of weekly alcohol intake.

Several authors have discussed the possibility that nonlinear dynamics might clarify substance abuse and chemical dependence. Nonlinear dynamical structure implies the possibility of oscillatory dynamics and high sensitivity to external perturbation. In this single-subject case study we analyzed the alcohol intake of a substance-abusing participant over a period of about five years using nonlinear time series analysis. The intake is measured in ounces per week and ounces per four weeks--approximately one month--yielding time series at two different time scales. We present statistical evidence that the participant's alcohol intake is nonlinear on both weekly and monthly time scales. We then discuss the implications of this multiscale nonlinearity for our understanding of substance abuse.

Corporate default behavior: a simple stochastic model.

We compare observed temporal dynamics of corporate default to a first-passage-time model and find that corporations default as if via diffusive dynamics.