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Polyanionic Non-Collagenous Proteins and Their Analogues Promote Artificial Mineralization of Embryonic Mouse Bone
Get PDFNon-collagenous proteins (NCPs) are specialized biomacromolecules within the extracellular matrix (ECM) that regulate the mineralization of calcified tissues, such as bone and dentin. Numerous in vitro studies have demonstrated that natural polyanionic NCPs and their analogues can mediate intrafibrillar mineralization, characterized by the infiltration of apatite minerals into collagen fibrils. However, these studies primarily utilize self-assembled collagen fibrils or demineralized mature tissues, leaving it unclear whether pristine embryonic bone ECM at a developmental stage permissive to mineral deposition can regulate intrafibrillar mineralization independently or requires polyanionic NCP substitutes to promote the process artificially. To address this, we employed an ex vivo model of endochondral ossification using metatarsals isolated from 15-day-old embryonic mice (E15). In addition to a supersaturated calcium (Ca) and inorganic phosphate (Pi) medium, we introduced fetuin-A, a native polyanionic NCP or poly-DL-aspartic acid (pAsp), commonly used as an NCP substitute. The incorporation of either additive was essential for the effective mineralization of embryonic metatarsals. Both fetuin-A and pAsp played a direct role in facilitating the infiltration of Ca-Pi precursors into the avascular cartilaginous matrix. Raman spectroscopy and electron microscopy confirmed the formation of hydroxyapatite (HAp) exhibiting diverse levels of crystallinity, with fetuin-A supplementation resulting in the greatest HAp accumulation within the rudiments. HAp was localized in the perichondrium, a region conducive to initial mineralization and enriched with a fibrillar network of collagen types I and II. Three-dimensional reconstructions implementing Dijkstra’s algorithm revealed the association between HAp and collagen fibrils either organized in an intrafibrillar, extrafibrillar, or combined arrangement
Data from: Malaria parasites adjust liver stage development to synchronise the blood stage of infections with host daily rhythms.
No full textSynchronised multiplication of Plasmodium parasites within red blood cells causes periodic malaria fevers. Aligning blood-stage development with the vertebrate host’s feeding-fasting rhythm facilitates within-host survival and between-host transmission. We use the rodent model Plasmodium chabaudi to test when, following development in the liver, the blood stage of infection begins. We find egress from the liver into the blood is aligned with the time of day of rhythmic host feeding, but only in wild type hosts, with egress occurring after a fixed period of pre-erythrocytic development in hosts without a functional canonical clock. However, perturbing the duration over which parasites enter the bloodstream does not affect their multiplication rate in the first few IDCs, suggesting any fitness benefits from times egress may occur later during the infection
A Robust Multi-Floor Wi-Fi Fingerprinting Approach Based on Geospatial Cells for Indoor Localization
No full textWi-Fi fingerprinting uses wireless signals to locate smartphone users indoors effectively. This method is popular because many buildings have numerous wireless access points available. However, due to the complex multi-floor indoor environment with its inherent signal dynamics, it suffers from: 1) computationally inefficient and complex algorithms designed to overcome the spatial unevenness and feature sparsity of the dataset; 2) high sensitivity to environmental dynamics; and 3) low accuracies due to signal fluctuations and inconsistencies between the physical and signal domains. To address these issues, we formulated a robust Wi-Fi fingerprinting approach for multi-floor indoor localization that accurately finds the user’s residing floor and location coordinates. The computational complexities are reduced by organizing the reference points (RPs) into geospatial cells (G-cells), extracting useful statistical features, and finding the localized cells (LCs) leveraging the knowledge of cell APs common with the test point (CATP) and the nearest reference point (N-RP). The algorithm removes outlier N-RPs, and the localized KNN algorithm (L-KNN) finds the real-time user’s coordinates accurately and efficiently. The floor identification algorithm, comprising two modules, segregates LCs into a layered format and utilizes information from neighboring floors’ APs common to the test point to overcome spatial unevenness between training and test samples. Extensive experiments are conducted on three real-world datasets. The results demonstrate that the proposed approach has superior localization accuracy and robustness compared to the best methods in the literature
Cognitive factors in code-switching:In response to Bentahila and Davies (1992)
Get PDFBilinguals’ tendency to switch between their languages (also known as code-switching) and the cognitive processes driving it are now known to be predicted by a variety of cognitive factors specific to the individual. In this review paper, we reflect on 30 years of progress in the study of the cognitive factors that determine how and when bilinguals switch between languages since Bentahila and Davies’ (1992) chapter on the relationship between code-switching and language dominance. We discuss how their work reflected a growing emphasis on moving beyond a strictly linguistic framework to focus on the psychological and social context in which code-switching occurs, and on the speaker-specific factors that affect the behaviour. We review and evaluate some of the substantial body of subsequent quantitative research about language switching and its relationship to language dominance, lexical access, cognitive control and interactional contexts. Some of these areas, like cognitive control, have seen considerable progress in understanding in the last thirty years and have substantially contributed to the development of psychological theories of bilingualism. Others we are only more recently beginning to understand, such as the effect of interactional contexts on the cognition of code-switching. The data yield a complex and sometimes contradictory picture but overall demonstrate that a range of social and psychological factors affect code-switching behaviours in ways that offer insights into the cognitive basis of code-switching
Stochastic profit maximization and pricing in hub location problems with elastic demand:Mathematical formulations and exact algorithms
Get PDFThis paper addresses profit maximization and pricing in capacitated and uncapacitated single allocation hub location problems taking into account the uncertain and price-elastic demand. We formulate the problem as a two-stage stochastic program in which a finite set of discrete price values are used to derive the demand. The models aim to determine simultaneously the location of hubs, the allocation of nodes to the hubs, the pricing decisions and the routing of demand within the network in order to maximize profit. The mathematical formulations for small uncapacitated and capacitated problems can be solved to optimality by commercial solvers. To solve large instances, we develop a Benders decomposition algorithm and an enhanced Lagrangian relaxation technique. We conduct extensive computational experiments using two well-known hub location datasets and present numerical results and analysis along with managerial insights
Weight misperception and non-fatal suicidal behaviors among U.S. adolescents:A V-shaped association and gender differences
No full textBackground: Existing evidence has identified that both weight overestimation and underestimation may elevate the risk of mental health issues in adolescents, such as depression and other externalizing and internalizing symptoms. However, this V-shaped association remains unclear with non-fatal suicidal behaviors (NFSB, including suicidal ideation, plan, and attempt), a serious mental health concern. Measurement and gender might account for that uncertainty. Methods: Based on a representative pooled U.S. cross-sectional Youth Risk Behavior Survey across five biennial cycles (2013–2021, n = 47,784; 50.6 % female), we first reconstructed a continuous measure of weight misperception using normalization techniques to mitigate the limitation of traditional categorical measures. We then examined its non-linear association with NFSB using restricted cubic spline technique in R. For comparability and interpretability, the continuous variable was further converted into a three-category measure to evaluate its V-shaped relationship with NFSB overall and by gender through logistic regression in Mplus. To obtain a more generalizable conclusion, year-specific estimates were synthesized using meta-analysis. Results: Compared to accurate perception group, both the overestimation and underestimation groups exhibited a higher risk of NFSB. This V-shaped association showed a significant gender difference, remaining evident among females but not among males, in whom underestimation was not significantly associated with NFSB. Meta-analysis found both weight overestimation (ORs: 1.82, 1.69, 1.69) and underestimation (ORs: 1.39, 1.36, 1.42) significantly increased odds of suicidal ideation, plan, and attempt, with consistently stronger associations for overestimation. Conclusions: Weight misperception exhibits an independent V-shaped association with NFSB, with gender-related heterogeneity implying the involvement of distinct underlying mechanisms
Sensitivity of familial high-risk approaches for the identification of future bipolar disorder: A longitudinal total birth cohort study
Get PDFBackgroundExtensive research has demonstrated an increased risk of bipolar disorder (BD) in individuals with familial high-risk for BD (FHR-BD). To date, however, it has not been demonstrated what proportion of all BD cases are captured by the FHR-BD approach. This is essential information because it identifies the upper limit of BD cases that could be prevented using the FHR-BD approach, if we had an effective preventive intervention.MethodsAll individuals born in Finland 1987–1992 (index children) were identified in health care registers and linked with maternal and paternal data. Of all BD diagnoses in the population by age 29, we assessed the proportion that occurred in individuals with a parental history of BD (FHR-BD). As an additional novel transdiagnostic approach, we also assessed the proportion of BD diagnoses that occurred in individuals who had a parental history of psychiatric admission for any reason (transdiagnostic familial risk; TDFR-BD).ResultsOf all index children (n = 368,779), 2.4 % (n = 8673) met FHR-BD criteria and 15.3 % (n = 56,483) met TDFR-BD criteria. Of all individuals diagnosed with BD, 7.8 % (CI: 6.9–8.7, n = 307) met FHR-BD criteria and 27.2 % (CI: 25.8–28.6 %, n = 1061) met TDFR-BD criteria prior to diagnosis. Absolute risk of BD in FHR-BD children and TDFR-BD children was 4.1 % (CI: 3.6–4.6 %, n = 307) and 2.2 % (CI: 2.0–2.4 %, n = 1061), respectively.ConclusionsOnly a small proportion (7.8 %) of BD cases are identified using the FHR-BD approach. Our findings highlight the importance of prediction research investigating not only absolute or relative risk, but also the sensitivity of different approaches to identifying risk
Use of a spot-check protocol to measure ventricular response rate in dogs with atrial fibrillation: Ventricular rate spot-check protocol in dogs with atrial fibrillation
Get PDFIntroduction: Fast ventricular response rates (VRR) have negative prognostic value in atrial fibrillation (AF). Therapeutic recommendations for canine AF rely on measurements of VRR from ambulatory electrocardiograms (aECG). Materials methods: Data from aECG of dogs with AF were prospectively acquired alongside VRR measurements obtained at home using a smartphone-based ECG device between 7:00 and 23:00. From these data, three protocols were outlined: (A) five predetermined spot-checks, (B) three six-hourly spot-checks, and (C) three eight-hourly spot-checks. The performance of the protocols was compared with aECG using mesor, mean and median VRR. The presence of circadian variation was explored using cosinor analysis.Results: Eighteen aECG were analysed, and 14 were used to test the spot-check protocols. The protocols showed moderate to strong correlation with aECG, with protocol B performing best (mean, r=0.84, P=<0.0001, bias -22.96, limits of agreement (LOA) 24.4; median, r=0.90, P=<0.0001, bias -24.48, LOA 22.04). Using a mean VRR < 125 beats per minute (bpm) as cut-off, 10/14 dogs (71.4%) hadinadequate VRR control. All protocols correctly identified these dogs, with protocol A performing best for mean VRR > 140 bpm. Circadian variation in VRR was identified in 17/18 dogs (94%).Limitations: Small population, high prevalence of inadequate VRR, non-standardised treatment, potential measurement artefact, lack of outcome data and precise temporal alignment with aECG recordings.Conclusions: Spot-check protocols offer a practical, affordable alternative to aECG for VRR assessment in dogs with AF. We have established that mean VRR > 140 bpm in the protocol predicts inadequate rate control on aECG
Experimental and theoretical analysis of a spontaneous Leidenfrost transitioning phenomenon
No full textThis study offers a thorough experimental and theoretical analysis of a unique droplet behavior known as spontaneous Leidenfrost transitioning (SLT). This phenomenon occurs between stable transitional boiling and Leidenfrost rebound. By creating a novel experimental platform that allows for spatial observations of hydrodynamic and thermodynamic behaviors, we uncover significant insights into SLT. Our experimental observations indicate that the occurrence of SLT is independent of the Bond number. However, a higher temperature is necessary to trigger SLT as the Bond number increases. Initially, SLT expands but narrows with rising Weber number, with larger Bond numbers exhibiting earlier narrowing due to intensified thermal-induced instability. Furthermore, enhanced surface smoothness and hydrophilicity are unfavorable for SLT initiation. We identify three distinct phases of SLT: intensive boiling, consecutive levitation, and stable Leidenfrost rebound. By analyzing three hydrodynamic parameters during the second phase, we propose a mechanism describing the evolution of SLT at increasing temperatures. Our investigations into phase transitions reveal that rapid retraction and the formation of a central lift force drive the transition from intensive boiling to consecutive levitation. We also establish a theoretical model to describe the subsequent transition into stable Leidenfrost rebound, which validates the case-sensitive nature of the proposed mechanism while successfully linking it to droplet deformation and heat transfer behavior. These findings provide valuable insights into the underexplored droplet behaviors between two well-known regimes, enhancing the understanding of transitional boiling instability and the transition from stable transitional boiling to Leidenfrost rebound
Transforming Siliconization into Slippery Liquid-like Coatings
No full textSiliconization is a specific coating technique to engineer surface properties in the pharmaceutical and medical device industries to lubricate motion, ensure complete dispensation of product, and to inhibit protein adsorption and biofilm growth. However, the focus has been on optimizing hydrophobicity, whereas liquid shedding is dominated by static and kinetic contact line friction. Here, we report a simple-to-apply coating method with optimization of ultra-low contact angle hysteresis liquid-like coatings for glass (G), polydimethylsiloxane (PDMS), polyurethane (PU) and stainless steel (SS); materials which are used for pharmaceutical/parenteral packaging and medical equipment. Moreover, we demonstrate that the coating's slow sliding dynamics surface properties for water droplets caused by high droplet kinetic friction, can be converted into fast sliding dynamics corresponding to low droplet kinetic friction, by a simple molecular capping (methylation) process. Our results provide new insight into key aspects of siliconization coatings in the context of industrial/commercial processes
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