2,077 research outputs found
Constraints on the Geometry and Frictional Properties of the Main Himalayan Thrust Using Coseismic, Postseismic, and Interseismic Deformation in Nepal
The geometry and frictional properties of a fault system are key parameters required to understand its seismic behavior. The Main Himalayan Thrust in Nepal is the type example of a continental megathrust and forms part of a fault system which accommodates a significant fraction of India‐Eurasia convergence. Despite extensive study of this zone of shortening, the geometry of the fault system remains controversial. Here, we use interseismic, coseismic, and postseismic geodetic data in Nepal to investigate the proposed downdip geometries. We use interseismic and coseismic data from previous studies, acquired before and during the 2015 urn:x-wiley:jgrb:media:jgrb53987:jgrb53987-math-0001 7.8 Gorkha earthquake. We then supplement these by processing our own postseismic deformation data, acquired following the Gorkha earthquake. We find that kinematic modeling of geodetic data alone cannot easily distinguish between the previously proposed geometries. We therefore develop a mechanical joint coseismic‐postseismic slip inversion which simultaneously solves for the distribution of coseismic slip and rate‐strengthening friction parameters. We run this inversion using the proposed geometries and find that they are all capable of explaining the majority of geodetic data. We find values for the rate parameter, urn:x-wiley:jgrb:media:jgrb53987:jgrb53987-math-0002, from the rate‐and‐state friction law that are between 0.8 and urn:x-wiley:jgrb:media:jgrb53987:jgrb53987-math-0003, depending on the geometry used. These values are in agreement with results from laboratory studies and those inferred from other earthquakes. We suggest that the limitations of earthquake cycle geodesy partly explain the continued controversy over the geometry and role of various faults in the Nepal Himalaya
A commercial arbuscular mycorrhizal inoculum increases root colonization across wheat cultivars but does not increase assimilation of mycorrhiza‐acquired nutrients
Production and heavy application of chemical‐based fertilizers to maintain crop yields is unsustainable due to pollution from run‐off, high CO2 emissions, and diminishing yield returns. Access to fertilizers will be limited in the future due to rising energy costs and dwindling rock phosphate resources. A growing number of companies produce and sell arbuscular mycorrhizal fungal (AMF) inoculants, intended to help reduce fertilizer usage by facilitating crop nutrient uptake through arbuscular mycorrhizas. However, their success has been variable. Here, we present information about the efficacy of a commercially available AMF inoculant in increasing AMF root colonization and fungal contribution to plant nutrient uptake, which are critical considerations within the growing AMF inoculant industry.
Summary
Arable agriculture needs sustainable solutions to reduce reliance on large inputs of nutrient fertilizers while continuing to improve crop yields. By harnessing arbuscular mycorrhizal symbiosis, there is potential to improve crop nutrient assimilation and growth without additional inputs, although the efficacy of commercially available mycorrhizal inocula in agricultural systems remains controversial.
Using stable and radioisotope tracing, carbon‐for‐nutrient exchange between arbuscular mycorrhizal fungi and three modern cultivars of wheat was quantified in a non‐sterile, agricultural soil, with or without the addition of a commercial mycorrhizal inoculant.
While there was no effect of inoculum addition on above‐ground plant biomass, there was increased root colonization by arbuscular mycorrhizal fungi and changes in community structure. Inoculation increased phosphorus uptake across all wheat cultivars by up to 30%, although this increase was not directly attributable to mycorrhizal fungi. Carbon‐for‐nutrient exchange between symbionts varied substantially between the wheat cultivars.
Plant tissue phosphorus increased in inoculated plants potentially because of changes induced by inoculation in microbial community composition and/or nutrient cycling within the rhizosphere. Our data contribute to the growing consensus that mycorrhizal inoculants could play a role in sustainable food production systems of the future
LiCSBAS: An Open-Source InSAR Time Series Analysis Package Integrated with the LiCSAR Automated Sentinel-1 InSAR Processor
For the past five years, the 2-satellite Sentinel-1 constellation has provided abundant and useful Synthetic Aperture Radar (SAR) data, which have the potential to reveal global ground surface deformation at high spatial and temporal resolutions. However, for most users, fully exploiting the large amount of associated data is challenging, especially over wide areas. To help address this challenge, we have developed LiCSBAS, an open-source SAR interferometry (InSAR) time series analysis package that integrates with the automated Sentinel-1 InSAR processor (LiCSAR). LiCSBAS utilizes freely available LiCSAR products, and users can save processing time and disk space while obtaining the results of InSAR time series analysis. In the LiCSBAS processing scheme, interferograms with many unwrapping errors are automatically identified by loop closure and removed. Reliable time series and velocities are derived with the aid of masking using several noise indices. The easy implementation of atmospheric corrections to reduce noise is achieved with the Generic Atmospheric Correction Online Service for InSAR (GACOS). Using case studies in southern Tohoku and the Echigo Plain, Japan, we demonstrate that LiCSBAS applied to LiCSAR products can detect both large-scale (>100 km) and localized (~km) relative displacements with an accuracy of <1 cm/epoch and ~2 mm/yr. We detect displacements with different temporal characteristics, including linear, periodic, and episodic, in Niigata, Ojiya, and Sanjo City, respectively. LiCSBAS and LiCSAR products facilitate greater exploitation of globally available and abundant SAR datasets and enhance their applications for scientific research and societal benefit
Improving the Resolving Power of InSAR for Earthquakes Using Time Series: A Case Study in Iran
Interferometric Synthetic Aperture Radar (InSAR) is an established method to measure earthquake surface displacements. However, due to decorrelation and atmospheric noise, only a certain fraction of earthquakes is readily observable with single interferograms. To enhance the potential of retrieving InSAR earthquake observations, we apply InSAR time series analysis and use several recent earthquakes (Mw 5.6–6.3, 2018–2019) in Iran as case studies. We find that the coseismic displacement signals of these earthquakes, which might not be discernible within single interferograms, are better resolved using our approach. We reconstruct the coseismic deformation fields by fitting surface displacements using a time series approach. We find that the reconstructed coseismic deformation fields yield more robust and seismologically consistent earthquake modeling results when compared to single coseismic interferograms. Our work suggests that a time series approach is an effective way to improve the resolving power of InSAR for earthquake studies
Autologous Cell Seeding in Tracheal Tissue Engineering
Purpose of Review: There is no consensus on the best technology to be employed for tracheal replacement. One particularly promising approach is based upon tissue engineering and involves applying autologous cells to transplantable scaffolds. Here, we present the reported pre-clinical and clinical data exploring the various options for achieving such seeding. Recent Findings: Various cell combinations, delivery strategies, and outcome measures are described. Mesenchymal stem cells (MSCs) are the most widely employed cell type in tracheal bioengineering. Airway epithelial cell luminal seeding is also widely employed, alone or in combination with other cell types. Combinations have thus far shown the greatest promise. Chondrocytes may improve mechanical outcomes in pre-clinical models, but have not been clinically tested. Rapid or pre-vascularization of scaffolds is an important consideration. Overall, there are few published objective measures of post-seeding cell viability, survival, or overall efficacy. Summary: There is no clear consensus on the optimal cell-scaffold combination and mechanisms for seeding. Systematic in vivo work is required to assess differences between tracheal grafts seeded with combinations of clinically deliverable cell types using objective outcome measures, including those for functionality and host immune response
Prediction of sarcomere mutations in subclinical hypertrophic cardiomyopathy.
BACKGROUND: Sarcomere protein mutations in hypertrophic cardiomyopathy induce subtle cardiac structural changes before the development of left ventricular hypertrophy (LVH). We have proposed that myocardial crypts are part of this phenotype and independently associated with the presence of sarcomere gene mutations. We tested this hypothesis in genetic hypertrophic cardiomyopathy pre-LVH (genotype positive, LVH negative [G+LVH-]). METHODS AND RESULTS: A multicenter case-control study investigated crypts and 22 other cardiovascular magnetic resonance parameters in subclinical hypertrophic cardiomyopathy to determine their strength of association with sarcomere gene mutation carriage. The G+LVH- sample (n=73) was 29 ± 13 years old and 51% were men. Crypts were related to the presence of sarcomere mutations (for ≥1 crypt, β=2.5; 95% confidence interval [CI], 0.5-4.4; P=0.014 and for ≥2 crypts, β=3.0; 95% CI, 0.8-7.9; P=0.004). In combination with 3 other parameters: anterior mitral valve leaflet elongation (β=2.1; 95% CI, 1.7-3.1; P<0.001), abnormal LV apical trabeculae (β=1.6; 95% CI, 0.8-2.5; P<0.001), and smaller LV end-systolic volumes (β=1.4; 95% CI, 0.5-2.3; P=0.001), multiple crypts indicated the presence of sarcomere gene mutations with 80% accuracy and an area under the curve of 0.85 (95% CI, 0.8-0.9). In this G+LVH- population, cardiac myosin-binding protein C mutation carriers had twice the prevalence of crypts when compared with the other combined mutations (47 versus 23%; odds ratio, 2.9; 95% CI, 1.1-7.9; P=0.045). CONCLUSIONS: The subclinical hypertrophic cardiomyopathy phenotype measured by cardiovascular magnetic resonance in a multicenter environment and consisting of crypts (particularly multiple), anterior mitral valve leaflet elongation, abnormal trabeculae, and smaller LV systolic cavity is indicative of the presence of sarcomere gene mutations and highlights the need for further study
The South Asian genome
Genetics of disease
Microarrays
Variant genotypes
Population genetics
Sequence alignment
AllelesThe genetic sequence variation of people from the Indian subcontinent who comprise one-quarter of the world's population, is not well described. We carried out whole genome sequencing of 168 South Asians, along with whole-exome sequencing of 147 South Asians to provide deeper characterisation of coding regions. We identify 12,962,155 autosomal sequence variants, including 2,946,861 new SNPs and 312,738 novel indels. This catalogue of SNPs and indels amongst South Asians provides the first comprehensive map of genetic variation in this major human population, and reveals evidence for selective pressures on genes involved in skin biology, metabolism, infection and immunity. Our results will accelerate the search for the genetic variants underlying susceptibility to disorders such as type-2 diabetes and cardiovascular disease which are highly prevalent amongst South Asians.Whole genome sequencing to discover genetic variants underlying type-2 diabetes, coronary heart disease and related phenotypes amongst Indian Asians. Imperial College Healthcare NHS Trust cBRC 2011-13 (JS Kooner [PI], JC Chambers)
From socioeconomic disadvantage to obesity: the mediating role of psychological distress and emotional eating
Objective: Lower socioeconomic status is robustly associated with obesity; however, the underpinning psychological mechanisms remain unclear. The current study sought to determine whether the relationship between lower socioeconomic status and obesity is explained by psychological distress and subsequent emotional eating as a coping strategy. It also examined whether psychological resilience plays a protective role in this pathway. Methods: Participants (N = 150) from a range of socioeconomic backgrounds completed questionnaire measures of psychological distress, emotional eating, and resilience. They reported their income and education level as an indicator of socioeconomic status and their height and weight in order to calculate BMI. Results: There was a significant indirect effect of socioeconomic status on BMI via psychological distress and emotional eating; specifically, lower socioeconomic status was associated with higher distress, higher distress was associated with higher emotional eating, and higher emotional eating was associated with higher BMI (b [SE] = −0.02 [0.01]; 95% CI: −0.04 to −0.01). However, resilience was not a significant moderator of this association. Conclusions: Psychological distress and subsequent emotional eating represent a serial pathway that links lower socioeconomic status with obesity. Targeting these maladaptive coping behaviors may be one strategy to reduce obesity in low-income populations. © 2019 The Authors. Obesity published by Wiley Periodicals, Inc. on behalf of The Obesity Society (TOS
Enhanced chlorhexidine skin penetration with 1,8-cineole
BACKGROUND: Chlorhexidine (CHG) penetrates poorly into skin. The purpose of this study was to compare the depth of CHG skin permeation from solutions containing either 2% (w/v) CHG and 70% (v/v) isopropyl alcohol (IPA) or 2% (w/v) CHG, 70% (v/v) IPA and 2% (v/v) 1,8-cineole. METHODS: An ex-vivo study using Franz diffusion cells was carried out. Full thickness human skin was mounted onto the cells and a CHG solution, with or without 2% (v/v) 1,8-cineole was applied to the skin surface. After twenty-four hours the skin was sectioned horizontally in 100 μm slices to a depth of 2000 μm and the concentration of CHG in each section quantified using high performance liquid chromatography (HPLC). The data were analysed with repeated measures analysis of variance. RESULTS: The concentration of CHG in the skin on average was significantly higher (33.3% [95%, CI 1.5% - 74.9%]) when a CHG solution which contained 1,8-cineole was applied to the skin compared to a CHG solution which did not contain this terpene (P = 0.042). CONCLUSIONS: Enhanced delivery of CHG can be achieved in the presence of 1,8-cineole, which is the major component of eucalyptus oil. This may reduce the numbers of microorganisms located in the deeper layers of the skin which potentially could decrease the risk of surgical site infection
M segment-based minigenomes and virus-like particle assays as an approach to assess the potential of tick-borne Phlebovirus genome reassortment
Bunyaviruses have a tripartite negative-sense RNA genome. Due to the segmented nature of these viruses, if two closely related viruses co-infect the same host or vector cell, it is possible that RNA segments from either of the two parental viruses are incorporated into progeny virions to give reassortant viruses. Little is known about the ability of tick-borne phleboviruses to reassort. The present study describes the development of minigenome assays for the tick-borne viruses Uukuniemi phlebovirus (UUKV) and Heartland phlebovirus (HRTV). We used these minigenome assays in conjunction with the existing minigenome system of SFTS phlebovirus (SFTSV) to assess the ability of viral N and L proteins to recognize, transcribe and replicate the M segment-based minigenome of a heterologous virus. The highest minigenome activity was detected with the M segment-based minigenome of cognate viruses. However, our findings indicate that several combinations utilizing N and L proteins of heterologous viruses resulted in M segment minigenome activity. This suggests that the M segment untranslated regions (UTRs) are recognised as a functional promoter of transcription and replication by the N and L proteins of related viruses. Further, virus-like particle assays demonstrated that HRTV glycoproteins can package UUKV and SFTSV S and L segment-based minigenomes. Taken together, these results suggest that co-infection of these viruses could lead to the generation of viable reassortant progeny. Thus, the tools developed herein could aid in understanding the role of genome reassortment in the evolution of these emerging pathogens under an experimental setting
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