The implicit power of positive thinking: The effect of positive episodic simulation on implicit future expectancies

Previous research demonstrating that positive episodic simulation enhances future expectancies has relied on explicit expectancy measures. The current study investigated the effects of episodic simulation on implicit expectancies. Using the Future Thinking Implicit Relational Assessment Procedure (FT-IRAP), participants made true/false decisions to indicate whether or not they expected positive/negative outcomes after adopting orientations consistent or inconsistent with an optimistic disposition. The outcome measure, DIRAP, was based on response time differences between consistent and inconsistent blocks. Participants then engaged in either positive simulation training, in which they imagined positive future events, or a neutral visualisation task before repeating the FT-IRAP twice following 10-minute intervals. Positive simulation training increased DIRAP scores for don’t-expect-negative trials – boosting participants’ readiness to affirm that negative events were unlikely to happen to them. Although findings did not generalise across all trial types, they show potential for positive simulation training to enhance implicit future expectancies

Photo-dynamics of quantum emitters in aluminum nitride

Aluminum nitride is a technologically important wide bandgap semiconductor which has been shown to host bright quantum emitters. In this paper, we probe the photodynamics of quantum emitters in aluminum nitride using photon emission correlations and time-resolved spectroscopy. We identify that each emitter contains as many as 6 internal energy levels with distinct laser power-dependent behaviors. Power-dependent shelving and de-shelving processes, such as optically induced ionization and recombination are considered, indicating complex optical dynamics associated with the spontaneous and optically pumped transitions. State population dynamics simulations qualitatively explain the temporal behaviours of the quantum emitters, revealing that those with pump-dependent de-shelving processes can saturate at significantly higher intensities, resulting in bright room-temperature quantum light emission.Comment: 20 pages. 5 figures in main text, 3 in supplementary inf

Ventricular endocardial tissue geometry affects stimulus threshold and effective refractory period

Background: Understanding the biophysical processes by which electrical stimuli applied to cardiac tissue may result in local activation is important in both the experimental and clinical electrophysiology laboratory environments, as well as for gaining a more in-depth knowledge of the mechanisms of focal-trigger-induced arrhythmias. Previous computational models have predicted that local myocardial tissue architecture alone may significantly modulate tissue excitability, affecting both the local stimulus current required to excite the tissue and the local effective refractory period (ERP). In this work, we present experimental validation of this structural modulation of local tissue excitability on the endocardial tissue surface, use computational models to provide mechanistic understanding of this phenomena in relation to localized changes in electrotonic loading, and demonstrate its implications for the capture of afterdepolarizations. Methods and Results: Experiments on rabbit ventricular wedge preparations showed that endocardial ridges (surfaces of negative mean curvature) had a stimulus capture threshold that was 0.21 ± 0.03 V less than endocardial grooves (surfaces of positive mean curvature) for pairwise comparison (24% reduction, corresponding to 56.2 ± 6.4% of the energy). When stimulated at the minimal stimulus strength for capture, ridge locations showed a shorter ERP than grooves (n = 6, mean pairwise difference 7.4 ± 4.2 ms). When each site was stimulated with identical-strength stimuli, the difference in ERP was further increased (mean pairwise difference 15.8 ± 5.3 ms). Computational bidomain models of highly idealized cylindrical endocardial structures qualitatively agreed with these findings, showing that such changes in excitability are driven by structural modulation in electrotonic loading, quantifying this relationship as a function of surface curvature. Simulations further showed that capture of delayed afterdepolarizations was more likely in trabecular ridges than grooves, driven by this difference in loading. Conclusions: We have demonstrated experimentally and explained mechanistically in computer simulations that the ability to capture tissue on the endocardial surface depends upon the local tissue architecture. These findings have important implications for deepening our understanding of excitability differences related to anatomical structure during stimulus application that may have important applications in the translation of novel experimental optogenetics pacing strategies. The uncovered preferential vulnerability to capture of afterdepolarizations of endocardial ridges, compared to grooves, provides important insight for understanding the mechanisms of focal-trigger-induced arrhythmias

Ocular pathology of uncommon hematologic malignancies: a case series

<p>Abstract</p> <p>Introduction</p> <p>In general, ocular complications of hematologic malignancies such as leukemia are well documented. However, reports of ocular involvement in such diseases as lymphomatoid granulomatosis and chronic myelomonocytic leukemia are uncommon. Here we present cases of these two relatively rare hematologic malignancies demonstrating clinical and subclinical ocular involvement.</p> <p>Case Presentation</p> <p>In the first case, a 54-year-old man with a previous diagnosis of lymphomatoid granulomatosis presented with a new-onset conjunctival lesion while his systemic disease was thought to be in remission. A biopsy was taken that revealed heavy infiltrates of B and T cells at the site of the lesion. Molecular analysis confirmed that these cells were positive for both Epstein-Barr viral DNA and immunoglobulin heavy chain gene rearrangement, consistent with a manifestation of his systemic disease. In the second case, a 51-year-old man with chronic myelomonocytic leukemia died after a waxing and waning clinical course. Post-mortem studies revealed the presence of atypical monocytes in the choroidal and subretinal spaces, consistent with his previous diagnosis.</p> <p>Conclusion</p> <p>While ocular involvement in hematologic malignancies is not uncommon, these two cases describe involvement of the eye by two relatively rare neoplasms. We herein emphasize novel findings in each case, including conjunctival involvement as the first sign of recurrent lymphomatoid granulomatosis and the combination of subretinal and choroidal myelomonocytic leukemic infiltration. With the evolution of new antineoplastic therapies that may prolong life, these cases exemplify the importance of eye care in patients diagnosed with hematologic malignancies.</p

Autoimmune Retinopathy in Systemic Lupus Erythematosus: Histopathologic Features

The ocular pathology of autoimmune retinopathy is demonstrated in a 62-year-old female patient with systemic lupus erythematosus (SLE) who presented with typical clinical autoimmune retinopathy. Macroscopically, there were multiple depigmented lesions in the peripheral retina and choroid and scattered pigmentary bone-spickling at the equator and periphery. Microscopically, there were generalized loss of photoreceptors and thinning of the outer plexiform layer. Many peripheral retinal vessels were sclerotic and occluded, some surrounded by pigment granules and RPE cells. Cobblestone degeneration was prominent in the periphery. Macrophages were seen in the retina, particularly in areas of photoreceptor degeneration. Rare, scattered T- lymphocytes were present in the retina and choroid, while B-cells were notably absent. The optic nerve showed loss of axons and thickened septae. Serum autoantibodies against normal retinal nuclei were detected. These pathological changes represent both known SLE-associated ocular complications as well as possible features of autoimmune retinopathy secondary to SLE

Autoimmune Retinopathy in Systemic Lupus Erythematosus: Histopathologic Features

The ocular pathology of autoimmune retinopathy is demonstrated in a 62-year-old female patient with systemic lupus erythematosus (SLE) who presented with typical clinical autoimmune retinopathy. Macroscopically, there were multiple depigmented lesions in the peripheral retina and choroid and scattered pigmentary bone-spickling at the equator and periphery. Microscopically, there were generalized loss of photoreceptors and thinning of the outer plexiform layer. Many peripheral retinal vessels were sclerotic and occluded, some surrounded by pigment granules and RPE cells. Cobblestone degeneration was prominent in the periphery. Macrophages were seen in the retina, particularly in areas of photoreceptor degeneration. Rare, scattered T- lymphocytes were present in the retina and choroid, while B-cells were notably absent. The optic nerve showed loss of axons and thickened septae. Serum autoantibodies against normal retinal nuclei were detected. These pathological changes represent both known SLE-associated ocular complications as well as possible features of autoimmune retinopathy secondary to SLE

Maternal pregnancy vitamin D supplementation increases offspring bone formation in response to mechanical loading: Findings from the MAVIDOS trial

The Maternal Vitamin D Osteoporosis (MAVIDOS) trial reported higher total body bone mineral content in winter-born infants of mothers receiving vitamin D supplementation [1000 IU/day cholecalciferol] compared with placebo from 14 weeks gestation until delivery. This sub-study aimed to determine whether antenatal vitamin D supplementation altered postnatal bone formation in response to mechanical stimulation. Thirty-one children born to MAVIDOS participants randomised to either placebo (n=19) or cholecalciferol (n=12) were recruited at age 4-5 years. Children received whole body vibration (WBV) for 10 minutes on 5 consecutive days. Fasting blood samples for bone homeostasis, 25 hydroxyvitamin D (25OHD), parathyroid hormone (PTH), and bone turnover markers (Pro-collagen Type 1 N-terminal propeptide, P1NP; Cross-linked C-telopeptide of Type I Collagen, CTX) were collected pre-WBV and on day 8 (D8). Mean changes (D) in P1NP (ng/ml) between baseline and D8 in the vitamin-D intervention and placebo groups were 40.6 and -92.6 respectively and mean changes (Δ) in CTX (ng/ml) were 0.034 (intervention) and -0.084 (placebo) respectively. Between-group DP1NP difference was 133.2ng/ml [95% CI 0.4, 266.0; p=0.049] and ΔCTX 0.05ng/ml (95% CI -0.159, 0.26ng/mL; p=0.62). Antenatal vitamin-D supplementation resulted in increased P1NP in response to WBV, suggesting early life vitamin D supplementation increases the anabolic response of bone to mechanical loading in children

Emission dynamics of optically driven aluminum nitride quantum emitters

Aluminum nitride is a technologically important wide band-gap semiconductor which has been shown to host bright quantum emitters. We use photon emission correlation spectroscopy (PECS), time-resolved photoluminescence (TRPL), and state-population dynamic simulations to probe the dynamics of emission under continuous wave (CW) and pulsed optical excitation. We infer that there are at least four dark shelving states, which govern the TRPL, bunching, and saturation of the optical transition. We study in detail the emission dynamics of two quantum emitters (QEs) with differing power-dependent shelving processes, hypothesized to result from charge ionization and recombination. These results demonstrate that photon bunching caused by shelving the system in a dark state inherently limits the saturation rate of the photon source. In emitters where increasing optical power deshelves the dark states, we observe an increased photon emission intensity

The protective effects of social bonding on behavioral and pituitary-adrenal axis reactivity to chronic mild stress in prairie voles.

Positive social interactions may protect against stress. This study investigated the beneficial effects of pairing with a social partner on behaviors and neuroendocrine function in response to chronic mild stress (CMS) in 13 prairie vole pairs. Following 5 days of social bonding, male and female prairie voles were exposed to 10 days of CMS (mild, unpredictable stressors of varying durations, for instance, strobe light, white noise, and damp bedding), housed with either the social partner (paired group) or individually (isolated group). Active and passive behavioral responses to the forced swim test (FST) and tail-suspension test (TST), and plasma concentrations of adrenocorticotropic hormone (ACTH) and corticosterone, were measured in all prairie voles following the CMS period. Both female and male prairie voles housed with a social partner displayed lower durations of passive behavioral responses (immobility, a maladaptive behavioral response) in the FST (mean ± SEM; females: 17.3 ± 5.4 s; males: 9.3 ± 4.6 s) and TST (females: 56.8 ± 16.4 s; males: 40.2 ± 11.3 s), versus both sexes housed individually (females, FST: 98.6 ± 12.9 s; females, TST: 155.1 ± 19.3 s; males, FST: 92.4 ± 14.1 s; males, TST: 158.9 ± 22.0 s). Female (but not male) prairie voles displayed attenuated plasma stress hormones when housed with a male partner (ACTH: 945 ± 24.7 pg/ml; corticosterone: 624 ± 139.5 ng/ml), versus females housed individually (ACTH: 1100 ± 23.2 pg/ml; corticosterone: 1064 ± 121.7 ng/ml). These results may inform understanding of the benefits of social interactions on stress resilience. Lay Summary: Social stress can lead to depression. The study of social bonding and stress using an animal model will inform understanding of the protective effects of social bonds. This study showed that social bonding in a rodent model can protect against behavioral responses to stress, and may also be protective against the elevation of stress hormones. This study provides evidence that bonding and social support are valuable for protecting against stress in humans

The implicit power of positive thinking: The effect of positive episodic simulation on implicit future expectancies

Previous research demonstrating that positive episodic simulation enhances future expectancies has relied on explicit expectancy measures. The current study investigated the effects of episodic simulation on implicit expectancies. Using the Future Thinking Implicit Relational Assessment Procedure (FT-IRAP), participants made true/false decisions to indicate whether or not they expected positive/negative outcomes after adopting orientations consistent or inconsistent with an optimistic disposition. The outcome measure, DIRAP, was based on response time differences between consistent and inconsistent blocks. Participants then engaged in either positive simulation training, in which they imagined positive future events, or a neutral visualisation task before repeating the FT-IRAP twice following 10-minute intervals. Positive simulation training increased DIRAP scores for don’t-expect-negative trials–boosting participants’ readiness to affirm that negative events were unlikely to happen to them. Although findings did not generalise across all trial types, they show potential for positive simulation training to enhance implicit future expectancies