45 research outputs found

    Counting function fluctuations and extreme value threshold in multifractal patterns: the case study of an ideal 1/f1/f noise

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    To understand the sample-to-sample fluctuations in disorder-generated multifractal patterns we investigate analytically as well as numerically the statistics of high values of the simplest model - the ideal periodic 1/f1/f Gaussian noise. By employing the thermodynamic formalism we predict the characteristic scale and the precise scaling form of the distribution of number of points above a given level. We demonstrate that the powerlaw forward tail of the probability density, with exponent controlled by the level, results in an important difference between the mean and the typical values of the counting function. This can be further used to determine the typical threshold xmx_m of extreme values in the pattern which turns out to be given by xm(typ)=2βˆ’cln⁑ln⁑M/ln⁑Mx_m^{(typ)}=2-c\ln{\ln{M}}/\ln{M} with c=3/2c=3/2. Such observation provides a rather compelling explanation of the mechanism behind universality of cc. Revealed mechanisms are conjectured to retain their qualitative validity for a broad class of disorder-generated multifractal fields. In particular, we predict that the typical value of the maximum pmaxp_{max} of intensity is to be given by βˆ’ln⁑pmax=Ξ±βˆ’ln⁑M+32fβ€²(Ξ±βˆ’)ln⁑ln⁑M+O(1)-\ln{p_{max}} = \alpha_{-}\ln{M} + \frac{3}{2f'(\alpha_{-})}\ln{\ln{M}} + O(1), where f(Ξ±)f(\alpha) is the corresponding singularity spectrum vanishing at Ξ±=Ξ±βˆ’>0\alpha=\alpha_{-}>0. For the 1/f1/f noise we also derive exact as well as well-controlled approximate formulas for the mean and the variance of the counting function without recourse to the thermodynamic formalism.Comment: 28 pages; 7 figures, published version with a few misprints corrected, editing done and references adde

    Ovine Fetal Thymus Response to Lipopolysaccharide-Induced Chorioamnionitis and Antenatal Corticosteroids

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    RATIONALE: Chorioamnionitis is associated with preterm delivery and involution of the fetal thymus. Women at risk of preterm delivery receive antenatal corticosteroids which accelerate fetal lung maturation and improve neonatal outcome. However, the effects of antenatal corticosteroids on the fetal thymus in the settings of chorioamnionitis are largely unknown. We hypothesized that intra-amniotic exposure to lipopolysaccharide (LPS) causes involution of the fetal thymus resulting in persistent effects on thymic structure and cell populations. We also hypothesized that antenatal corticosteroids may modulate the effects of LPS on thymic development. METHODS: Time-mated ewes with singleton fetuses received an intra-amniotic injection of LPS 7 or 14 days before preterm delivery at 120 days gestational age (termβ€Š=β€Š150 days). LPS and corticosteroid treatment groups received intra-amniotic LPS either preceding or following maternal intra-muscular betamethasone. Gestation matched controls received intra-amniotic and maternal intra-muscular saline. The fetal intra-thoracic thymus was evaluated. RESULTS: Intra-amniotic LPS decreased the cortico-medullary (C/M) ratio of the thymus and increased Toll-like receptor (TLR) 4 mRNA and CD3 expression indicating involution and activation of the fetal thymus. Increased TLR4 and CD3 expression persisted for 14 days but Foxp3 expression decreased suggesting a change in regulatory T-cells. Sonic hedgehog and bone morphogenetic protein 4 mRNA, which are negative regulators of T-cell development, decreased in response to intra-amniotic LPS. Betamethasone treatment before LPS exposure attenuated some of the LPS-induced thymic responses but increased cleaved caspase-3 expression and decreased the C/M ratio. Betamethasone treatment after LPS exposure did not prevent the LPS-induced thymic changes. CONCLUSION: Intra-amniotic exposure to LPS activated the fetal thymus which was accompanied by structural changes. Treatment with antenatal corticosteroids before LPS partially attenuated the LPS-induced effects but increased apoptosis in the fetal thymus. Corticosteroid administration after the inflammatory stimulus did not inhibit the LPS effects on the fetal thymus

    Preleukemic single-cell landscapes reveal mutation-specific mechanisms and gene programs predictive of AML patient outcomes

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    Acute myeloid leukemia (AML) and myeloid neoplasms develop through acquisition of somatic mutations that confer mutation-specific fitness advantages to hematopoietic stem and progenitor cells. However, our understanding of mutational effects remains limited to the resolution attainable within immunophenotypically and clinically accessible bulk cell populations. To decipher heterogeneous cellular fitness to preleukemic mutational perturbations, we performed single-cell RNA sequencing of eight different mouse models with driver mutations of myeloid malignancies, generating 269,048 single-cell profiles. Our analysis infers mutation-driven perturbations in cell abundance, cellular lineage fate, cellular metabolism, and gene expression at the continuous resolution, pinpointing cell populations with transcriptional alterations associated with differentiation bias. We further develop an 11-gene scoring system (Stem11) on the basis of preleukemic transcriptional signatures that predicts AML patient outcomes. Our results demonstrate that a single-cell-resolution deep characterization of preleukemic biology has the potential to enhance our understanding of AML heterogeneity and inform more effective risk stratification strategies

    Comparison of bispectral index and end-tidal anaesthetic concentration monitoring on recovery profile of desflurane in patients undergoing lumbar spine surgery

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    Background and Aims: Several techniques have evolved over time to monitor depth of anesthesia and ensure enhanced recovery. This randomized double-blinded trial was designed to compare bispectral index (BIS) or end-tidal anaesthetic concentration (ETAC) monitoring on the recovery characteristics of patients undergoing thoracolumbar spine surgeries. Methods: Seventy American Society of Anesthesiologist I–II patients of either sex were randomized to Group B – BIS-guided protocol, Group E – ETAC-guided protocol, or Group S – Standard protocol. After intravenous induction, anaesthesia was maintained with desflurane in O2/N2O (50:50) mixture. In BIS, ETAC and Standard groups, inspired end-tidal desflurane concentration was varied to achieve BIS of 45–55, 0.8–1.0 age-corrected minimum alveolar concentration, and haemodynamic parameters within 20% of the baseline, respectively. Time to eye opening (emergence time, the primary outcome), time to extubation, and time to name recall from the discontinuation of the anaesthetic agent were recorded. Incidence of nausea, vomiting, and total analgesic consumption was noted for 24 h. Results: Emergence time (mean Β± SD) in ETAC (5.1 Β± 1.53 min) and BIS (5.0 Β± 2.12 min)-guided groups was significantly lower than Standard group (7.5 Β± 2.90 min). Extubation time in ETAC (6.3 Β± 2.22 min) and BIS-guided group (6.5 Β± 1.78 min) was significantly lower than Standard group (9.0 Β± 3.20 min) (P < 0.001). Time to achieve fast track score of more than 12 was significantly less in BIS-guided group (13.12 Β± 2.59 min). Conclusion: ETAC-guided anaesthesia is comparable to BIS-guided anaesthesia in achieving early recovery

    Ocular toxoplasmosis

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    Synthesis of Al 2

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    Case Report: Kikuchi-Fujimoto disease: a diagnostic and therapeutic dilemma following pretransplant nephrectomy for a 2.35 Kg kidney [version 1; referees: 2 approved]

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    Kikuchi-Fujimoto disease (KFD) is an extremely rare disease with a worldwide distribution and higher prevalence in Asians. It is a benign and self-limiting disorder, characterized by regional cervical lymphadenopathy accompanied with mild fever and night sweats. Lymph node histopathology is diagnostic and treating physicians should be aware of this entity as it may mimic other systemic diseases like systemic lupus erythematosus, tuberculosis, malignant lymphoma, and more rarely adenocarcinoma. Key features on lymph node biopsy are fragmentation, necrosis and karyorrhexis. Treatment includes symptomatic care, analgesics-antipyretics, corticosteroids and spontaneous recovery occurs in 1 to 4 months. We report a case of adult polycystic kidney disease (ADPKD) with end stage renal disease and episodes of fever and cervical lymphadenopathy. The infectious screen was negative and on extensive workup, the patient was found to have histiocytic-necrotizing lymphadenitis, which clinched the diagnosis of KFD

    Spatial analysis of gastroschisis in the national birth defects prevention study

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    BACKGROUND: Gastroschisis is a birth defect where loops of bowel are protruding from the abdominal wall at birth. Previous research has suggested that gastroschisis cases can occur in clusters. The objective of this study was to identify if there were areas of elevated gastroschisis risk using data from the National Birth Defects Prevention Study (NBDPS), 1997 through 2007. METHODS: We obtained data on cases (n=371) through population-based birth defects surveillance systems in Arkansas, California, and Utah; controls (n=2,359) were selected from the same geographic areas as cases. Mothers were interviewed on demographic information and exposures during pregnancy, including residential history. We used first trimester maternal addresses and generalized additive models to create a continuous map surface of odds ratios (OR) by smoothing over latitude and longitude. Permutation tests were used to assess whether location of maternal residence was important and identify locations with statistically significant ORs. RESULTS: In Arkansas, adjusted ORs in the southwest corner were 2.0 and the global deviance was not statistically significant (p-value: 0.57). Adjusted ORs for California indicated areas of increased risk with ORs 1.3 (p-value: 0.34). In Utah, the adjusted ORs were elevated (OR: 2.4) in the south-eastern corner of the study area (p-value: 0.34). CONCLUSION: The results of this study, while not statistically significant, suggest there were spatial variations in gastroschisis births. We cannot rule out that these variations were due to edge effects or residual confounding
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