1,435 research outputs found
Signatures of tetraether lipids reveal anthropogenic overprinting of natural organic matter in sediments of the Thames Estuary, UK
Intertidal foreshore sediments from a 110 km stretch of the Thames Estuary were analysed for glycerol dialkyl glycerol tetraethers (GDGTs) to track soil organic matter (OM) input and evaluate the impact of coastal urbanisation on their distribution. Concentration of branched (br)GDGTs ranged from < 1 to 15 μg/g organic carbon (OC) and crenarchaeol ranged from 0.6 to 19 μg/g OC. An overall decrease in brGDGTs was observed from the inner Thames (Brentford) to the outer Thames (Isle of Grain), suggesting a drop in soil OM input towards the sea. In contrast, crenarchaeol concentration was highest around east London rather than towards the open sea. Such elevated crenarchaeol concentration occurred in the section of the river most influenced by anthropogenic pollution, such as discharge points for London’s major sewage treatment plants, docks and power plants. The non-systematic spatial distribution of crenarchaeol was also reflected in the branched isoprenoid tetraether (BIT) index. The highest BIT values occurred upstream and in close proximity to salt marshes (0.8–1), whereas the lowest values (0.3–0.5) were towards the sea. However, unusually low values (0.4) were observed in the river section that had high crenarchaeol concentration. In contrast, bulk δ13C values were insensitive to London’s anthropogenic influence. This suggests that the natural systematic decrease in BIT index in the estuary is overprinted by London’s anthropogenic activity between Deptford Creek and Tilbury. We therefore advise caution when interpreting the BIT index for sediments in close proximity to megacities discharging industrial and municipal waste that can become incorporated into the near surface sedimentary record
Molecular and bulk geochemical proxies in sediments from the Conwy Estuary, UK
Owing to their restricted riverine flow and greater numbers, small estuaries (annual discharge < 2000 m3 s–1) are important sites of organic carbon (OC) storage in sediments. The Conwy Estuary is an exemplar small rural-agricultural catchment which delivers a diverse pool of terrestrial OC to the Irish Sea. Thirty-nine surface sediments, covering a distance of 10.5 km, were taken transversal as well as longitudinal to the estuary to examine local and distant catchment inputs. Biomarkers (branched Glycerol Dialkyl Glycerol Tetraethers - brGDGTs, n-alkanes) and molecular and bulk proxies (BIT, Paq, TAR, δ13C, C/N), showed sediments were dominated by terrestrial inputs, with only sediments of the three most seaward sites showing stronger physical and geochemical characteristics of a marine influence (e.g., sandier sediments and lower BIT). Biomarker concentrations in the Conwy were comparable to the more urbanised Thames and the Clyde estuaries. The three estuaries showed similar fractional abundance of the brGDGTs, recording an inverse trend between the hexamethylated and the tetramethylated brGDGTs, and showing the pentamethylated brGDGTs as the dominant group. A systematic decrease in terrestrial biomarkers from bank to the main channel confirmed either a strong localised erosion/runoff process or a decrease in water velocity leading to a higher deposition
Osteoarthritis associated with estrogen deficiency
Osteoarthritis (OA) affects all articular tissues and finally leads to joint failure. Although articular tissues have long been considered unresponsive to estrogens or their deficiency, there is now increasing evidence that estrogens influence the activity of joint tissues through complex molecular pathways that act at multiple levels. Indeed, we are only just beginning to understand the effects of estrogen deficiency on articular tissues during OA development and progression, as well as on the association between OA and osteoporosis. Estrogen replacement therapy and current selective estrogen receptor modulators have mixed effectiveness in preserving and/or restoring joint tissue in OA. Thus, a better understanding of how estrogen acts on joints and other tissues in OA will aid the development of specific and safe estrogen ligands as novel therapeutic agents targeting the OA joint as a whole organ
Yeast as a model organism for studying the evolution of non-standard genetic codes
During the last 30 years, a number of alterations to the standard genetic code have been uncovered both in prokaryotes and eukaryotic nuclear and mitochondrial genomes. But, the study of the evolutionary pathways and molecular mechanisms of codon identity redefinition has been largely ignored due to the assumption that non-standard genetic codes can only evolve through neutral evolutionary mechanisms and that they have no functional significance. The recent discovery of a genetic code change in the genus Candida that evolved through an ambiguous messenger RNA decoding mechanism is bringing that naive assumption to an abrupt end by showing, in a rather dramatic way, that genetic code changes have profound physiological and evolutionary consequences for the species that redefine codon identity. In this paper, the recent data on the evolution of the Candida genetic code are reviewed and an experimental framework based on forced evolution, molecular genetics and comparative and functional genomics methodologies is put forward for the study of non-standard genetic codes and genetic code ambiguity in general. Additionally, the importance of using Saccharomyces cerevisiae as a model organism for elucidating the evolutionary pathway of the Candida and other genetic code changes is emphasised.publishe
reactive oxygen species responsive nanoplatforms as smart drug delivery systems for gastrointestinal tract targeting
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Impact of tRNA modifications and tRNA-modifying enzymes on proteostasis and human disease
Transfer RNAs (tRNAs) are key players of protein synthesis, as they decode the genetic information organized in mRNA codons, translating them into the code of 20 amino acids. To be fully active, tRNAs undergo extensive post-transcriptional modifications, catalyzed by different tRNA-modifying enzymes. Lack of these modifications increases the level of missense errors and affects codon decoding rate, contributing to protein aggregation with deleterious consequences to the cell. Recent works show that tRNA hypomodification and tRNA-modifying-enzyme deregulation occur in several diseases where proteostasis is affected, namely, neurodegenerative and metabolic diseases. In this review, we discuss the recent findings that correlate aberrant tRNA modification with proteostasis imbalances, in particular in neurological and metabolic disorders, and highlight the association between tRNAs, their modifying enzymes, translational decoding, and disease onset.publishe
Aboriginal Women Against Violence Project Evaluation Report
In 2008 Joan Harrison’s Support Services for Women received funding under the National Community Crime Prevention Programme (NCCPP) in relation to the Aboriginal Women Against Violence Project. The overall aim of the project was ‘to address family violence in Aboriginal and Torres Strait Islander communities in Liverpool and Campbelltown areas’ (Attorney General’s Funding schedule). The project identified two specific strategies to achieve this general aim: to train local Aboriginal and Torres Strait Islander women to become trainer, mentors and advocates in their own communities;to establish an Aboriginal Women Against Violence Committee. This evaluation reports on the agreed outcomes identified in the funding agreement as well as identifying broader lessons arising from the project in relation to addressing violence in Aboriginal and Torres Strait Islander communities.Joan Harrison’s Support Services for Wome
Biomimetic platelet membrane-coated nanoparticles for targeted therapy
The development of cell membrane-modified biomimetic nanoparticles has extensively increased during the past years due to their exceptional biocompatibility, evasion from the immune system, and targeting ability. Known as a cutting-edge area of research in nanomedicine, such novel nanoplatforms can mimic different functions of the primary cells, while successfully delivering their cargos to the defect site with the aim of enhancing the therapeutic responses and reducing the side effects. Platelet is a key factor for haemostasis and a major player in wound healing, inflammation, and many other biological functions and pathological conditions. As a highly responsive cell, platelets can adapt to environment modifications and release several soluble biomolecules, such as growth factors, coagulant factors, and extracellular vesicles. Additionally, platelets are capable of immune system evasion, sub-endothelial adhesion, and pathogen interaction. These characteristics have inspired the design of several platelet membrane-coated nanoparticles as drug delivery systems. This review describes the current developments in platelet membrane-coated nanoparticles for targeted therapy, specifically, their advantages compared to other biomimetic cell-derived nanoparticles and their applicability in the medical field are elucidated. Finally, the challenges and future perspectives associated with this nanoplatform are summarised.Peer reviewe
Integrated approach to assess resonance between basin eigenmodes and moored ship motions with wavelet transform analysis and proposal of operational thresholds
Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG.[Abstract:] Waves with periods between 25 s and some minutes can amplify the motions of moored ships, which may result in terminal downtimes and compromise safety. The purpose of this work is twofold: (i) studying infragravity waves and their influence on moored ship motions, including the definition of operational thresholds and (ii) developing a novel and integrated approach to identify and assess resonance situations using wavelet transform analysis. The resonant modes of the harbor basin were identified using a numerical model validated with full-scale data. The motions of five similar LPG vessels moored at two adjacent jetties were analyzed, both in the frequency and frequency–time domains. It was concluded that surge is the most important motion at the berth that has greater operational problems. Moreover, the infragravity motion periods vary with the mooring line pretension and are proportional to the ratio of water depth to vessel draft. Three episodes of mooring line breaking were attributed to large infragravity surge oscillations. In addition, operational thresholds for basin-vessel resonance situations were defined based on the port tide gauge data. A significant wave height of 0.075 and 0.010 m for the 30–65 s period band was established for LPGs and oil tankers, respectively.Ministerio de EconomÃa, Industria y Competitividad; BIA2017-86738-RMinisterio de Ciencia e Innovación; PID2020-112794RB-I00 / AEI / 10.13039/501100011033Ministerio de Ciencia, Innovación y Universidades; PRE2018-08377
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