2,296 research outputs found
The response of a floating ice sheet to an accelerating line load
The two-dimensional response of a thin, floating sheet of ice to a line load that accelerates from rest at to a uniform velocity V for is determined through an integral-transform solution of the linearized equations of motion. If – i.e. if the load is impulsively started with velocity V – the solution exhibits singularities at , the shallow-water-gravity-wave speed, and , the minimum speed for transverse motion of the ice, but these singularities are avoided by the acceleration of the load through the critical speeds
Ameliorative Effects of Adansonia Digitata Leaf Extract on Carbon Tetrachloride (CCL4) Induced Testicular Toxicity in Adult Male Wistar Rats
Adansonia digitata is locally consumed as food in Nigeria. In the present study, the ameliorative effect of the aqueous leaf extract of Adansonia digitata (AeAD) was evaluated in carbon tetrachloride (CCl4) – induced testicular toxicity in Wistar rats. To evaluate the effect of AeAD in CCl4 induced testicular toxicity, 20 adult male Wistar rats were equally divided into 4 groups (n=5). Group A animals received 1 ml olive oil per os (p.o) for two weeks, Group B animals received 2.5 ml/kg CCl4 (50% in olive oil, p.o) for two days, Group C animals received 500 ml/kg AeAD (p.o) for two weeks while Group D animals received 2.5 ml/kg CCl4 (50% in olive oil, p.o) for two days followed by 500 ml/kg AeAD (p.o) for two weeks. The ameliorative effects of AeAD were observed on reproductive hormonal parameters, activity of an antioxidant enzyme and cyto-architecture of the testis. Carbon tetrachloride treatment significantly (P<0.05) reduced levels of testosterone, follicle stimulating hormone, luteinizing hormone and superoxide dismutase levels with distortions in the cyto-architecture of the testes in treated animals. These effects were ameliorated with AeAD treatment. The results demonstrated that the AeAD has the ability to ameliorate against carbontetrachloride-induced testicular toxicity suggesting it may have a therapeutic role in free radical mediated diseases.Keywords: Antioxidant; SOD; Testes; Histology
A twin study of cilioretinal arteries, tilted discs and situs inversus
PURPOSE: To establish the prevalence and heritability of cilioretinal arteries (CRAs), tilted discs (TDs) and situs inversus (SI). METHODS: Fundus photos from the Twins UK Adult Twin registry twin database were analyzed: 1812 individuals, 526 complete monozygotic (MZ) twin pairs and 336 complete dizygotic (DZ) pairs. Images were assessed non-stereoscopically on a computer screen by the same ophthalmologist for presence of CRAs, TDs or SI. Prevalence figures, probandwise concordances and heritabilities were calculated. RESULTS: Prevalence of a CRA in subjects’ right eyes was 28.6% (26.5–30.8). Prevalence of subjects with a CRA in at least one eye was 45.0% (42.6–47.5), with a TD in at least one eye was 1.2% (0.8–1.9), and with SI at least one eye was 0.5% (0.3–1.0). There was no association between birth weight and presence of CRA. Concordance for CRA in at least one eye (MZ twins) was 60% (95% CI 55–64), and (DZ) was 45% (95% CI 39–51). Heritability for CRAs in at least one eye was 49.4% (95% CI 38.1–59.7) and for both eyes was 32.9% (95% CI 10.4–53.3). We were unable to calculate meaningful heritabilities or concordances for TDs and situs SI, due to insufficient numbers. CONCLUSIONS: The presence of CRAs appears to be moderately heritable, with greater variance explained by individual environmental factors or even stochastic events. They were not associated with low birth weight. Future genetic research and studies of birth/lifecourse cohorts may offer further insights into the etiology of congenital papillovascular abnormalities
Interpreting (and misclassifying) fitness – what do we really mean by ‘normal’?
This is the author accepted manuscrip
A facile method for the stain-free visualization of hierarchical structures with electron microscopy
Diblock copolymers form hierarchical morphologies with numerous applications in drug delivery and as nanoreactors. Yet, the visualization of these structures by electron microscopy can be extremely difficult, requiring complex staining techniques with associated health risks and the potential to alter structural morphology. Reported here is the synthesis of diblock copolymers by RAFT containing 3,5-bis(trifluoromethyl)phenyl functionality allowing for facile visualization of their resulting hierarchical structures by TEM with no further sample preparation.P.E.W. thanks the AWE and E.A. thanks Schlumberger for financial support,
and J.d.B is grateful for a Marie Curie Intraeuropean Fellowship
(project # 273807). This work was also supported by an ERC Starting
Investigator Grant (ASPiRe) and a Next Generation Fellowship provided
by the Walters-Kundert Foundation.This is the accepted manuscript. The final published version is available from Wiley at http://onlinelibrary.wiley.com/doi/10.1002/pola.27517/abstract
Prevalence, Concordance, and Heritability of Vitreomacular Interface Abnormalities in a Twin Study
PURPOSE: The relative importance of genetic factors in common vitreomacular interface (VMI) abnormalities is unknown. The aim of this classical twin study is to determine the prevalence case wise concordance between monozygotic and dizygotic twin pairs, and heritability of common VMI abnormalities, including epiretinal membrane (ERM), posterior vitreous detachment (PVD), vitreomacular adhesion (VMA), vitreomacular traction (VMT), lamellar macular holes (LMHs), and full-thickness macular holes (FTMHs). METHODS: This is a single-center, cross-sectional classical twin study of 3406 TwinsUK participants over the age of 40 years who underwent spectral domain macular optical coherence tomography (SD-OCT) scans which were graded for signs of VMI abnormalities. Case wise concordance was calculated and the heritability of each VMI abnormality was estimated using OpenMx structural equation modeling. RESULTS: In this population (mean age = 62.0 years [SD = 10.4 years], range = 40–89 years) the overall prevalence of ERM was 15.6% (95% confidence interval [CI] = 14.4–16.9) and increased with age, posterior vitreous detachment affected 21.3% (20.0–22.7), and VMA was diagnosed in 11.8% (10.8–13.0). Monozygotic twins were more concordant for all traits than dizygotic twins, and age, spherical equivalent refraction (SER), and lens status-adjusted heritability was estimated at 38.9% (95% CI = 33.6–52.8) for ERM, 53.2% (95% CI = 41.8–63.2) for PVD, and 48.1% (95% CI = 33.6–58) for VMA. CONCLUSIONS: Common VMI abnormalities are heritable and therefore have an underlying genetic component. Given the sight-threatening potential of VMI abnormalities, further genetic studies, such as genomewide association studies, would be useful to identify genes and pathways implicated in their pathogenesis
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Down-delta hydraulic geometry and its application to the rock record
Data Availability Statement: Data from this paper are publicly available at https://doi.org/10.6084/m9.figshare.19574938.v2.This research was funded by an award from the Indonesia Endowment Fund for Education (LPDP) to Prasojo. The global river discharge dataset is available from The Global Runoff Data Centre (GRDC), 56068 Koblenz, Germany or and via the web (http://www.bafg.de/grdc.htm).Copyright . Palaeodischarge estimation is largely undertaken within fluvial settings. However, there are limited palaeodischarge estimates specifically from delta deposits, despite their significance globally. Estimating water palaeodischarges for deltas using catchment-based approaches developed using data from fluvial settings requires estimating parameters from the rock record (for example, palaeotemperature, palaeoslope and palaeorelief). These may be difficult to determine, leading to under-estimation or over-estimation of palaeodischarge values due to differences in process-form relationships between alluvial rivers and deltas. When a sediment-conveying fluvial channel enters a standing body of water, delta lobes develop through repeating mouth bar deposition due to flow deceleration, forming a deltaic morphology with distributary channel networks that differ morphologically from those developed in unidirectional flowing alluvial rivers. This study provides empirical relationships determined across five climate regions, using 3823 measurements of distributary channel width from 66 river deltas alongside the trunk river bankfull discharge that feeds into the entire delta, using a hydraulic geometry scaling approach. Empirical relationships are developed from the global delta dataset between bankfull discharge and catchment area (Qb–A), and bankfull discharge and median distributary channel width (Qb–Wmed). These empirical relationships produce very strong statistical correlations, especially between Qb and Wmed, across different climate regions (Qb = 0.34 Wmed1.48, R2 = 0.77). However, both Qb–A and Qb–Wmed relationships have outliers that may be explained by particular hydrological or geomorphic conditions. These new empirical relationships derived from modern systems are then applied to Cretaceous outcrops (Ferron Sandstone and Dunvegan Formation). The comparatively simple scaling relationships derived here produced palaeodischarge estimates within the same order of magnitude as palaeodischarge values previously obtained using existing, more complex approaches. This study contributes to source-to-sink investigations by enabling palaeodischarge estimates that intrinsically account for climate impacts on channel geometry at the time of deposition, using measurements of channel width or catchment area of a deltaic outcrop.Lembaga Pengelola Dana Pendidikan. Grant Number: 20190222021387
Process Mining in Primary Care: A Literature Review
Process mining is the discipline of discovering processes from event logs, checking the conformance of real world events to idealized processes, and ultimately finding ways to improve those processes. It was originally applied to business processes and has recently been applied to healthcare. It can reveal insights into clinical care pathways and inform the redesign of healthcare services. We reviewed the literature on process mining, to investigate the extent to which process mining has been applied to primary care, and to identify specific challenges that may arise in this setting. We identified 143 relevant papers, of which only a small minority (n=7) focused on primary care settings. Reported challenges included data quality (consistency and completeness of routinely collected data); selection of appropriate algorithms and tools; presentation of results; and utilization of results in real-world applications
Single-molecule force spectroscopy quantification of adhesive forces in cucurbit[8]uril host-guest ternary complexes.
Cucurbit[8]uril (CB[8]) heteroternary complexes display certain characteristics making them well-suited for molecular level adhesives. In particular, the ability to control adhesion through careful choice of host-guest binding pairs enables specific, fully reversible adhesion. Understanding the effect of the environment on the adhesive system is also critical when developing new molecular level adhesives. Here we explore the binding forces involved in the methyl viologen · CB[8] · napthol heteroternary complex using single-molecule force spectroscopy (SMFS) under a variety of conditions. From SMFS, the interaction of a single ternary complex was found to be in the region of 140 pN. Additionally, a number of surface interactions could be readily differentiated using the SMFS technique allowing for a deeper understanding of the dynamic heteroternary CB[8] system on the single-molecule scale.This work was supported in part by the Engineering and Physical Sciences Research Council (EPSRC), the Walters-Kundert Charitable Trust and an ERC Starting Investigator grant (ASPiRe, 240629). ZWK, ERJ, YL thank the Royal Society of Chemistry for a grant allowing travel to Tsinghua University to carry out this research. YY would like to acknowledge financial support from the Young Scientists of the National Science Foundation of China (21304052). YL thanks the Chinese Overseas Scholarship Trust for financial support. JdB thanks the Marie Curie Actions program for financial support. PEW thanks the Atomic Weapons and Energy Commission and the Melville Laboratory for Polymer Synthesis for financial support
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