1,318 research outputs found

    Monitoring of offshore geological carbon storage integrity: Implications of natural variability in the marine system and the assessment of anomaly detection criteria

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    The design of efficient monitoring programmes required for the assurance of offshore geological storage requires an understanding of the variability and heterogeneity of marine carbonate chemistry. In the absence of sufficient observational data and for extrapolation both spatially and seasonally, models have a significant role to play. In this study a previously evaluated hydrodynamic-biogeochemical model is used to characterise carbonate chemistry, in particular pH heterogeneity in the vicinity of the sea floor. Using three contrasting regions, the seasonal and short term variability are analysed and criteria that could be considered as indicators of anomalous carbonate chemistry identified. These criteria are then tested by imposing a number of randomised DIC perturbations on the model data, representing a comprehensive range of leakage scenarios. In conclusion optimal criteria and general rules for developing monitoring strategies are identified. Detection criteria will be site specific and vary seasonally and monitoring may be more efficient at periods of low dynamics. Analysis suggests that by using high frequency, sub-hourly monitoring anomalies as small as 0.01 of a pH unit or less may be successfully discriminated from natural variability – thereby allowing detection of small leaks or at distance from a leakage source. Conversely assurance of no leakage would be profound. Detection at deeper sites is likely to be more efficient than at shallow sites where the near bed system is closely coupled to surface processes. Although this study is based on North Sea target sites for geological storage, the model and the general conclusions are relevant to the majority of offshore storage sites lying on the continental shelf

    Real and virtual polymorphism of titanium selenide with robust interatomic potentials

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    The first successful pairwise potential for a layered material, TiSe2, has been parameterised to fit the experimental data, using a genetic algorithm as the optimisation tool for the parameters of the interatomic potential

    Clinical relevance of the transcriptional signature regulated by CDC42 in colorectal cancer.

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    CDC42 is an oncogenic Rho GTPase overexpressed in colorectal cancer (CRC). Although CDC42 has been shown to regulate gene transcription, the specific molecular mechanisms regulating the oncogenic ability of CDC42 remain unknown. Here, we have characterized the transcriptional networks governed by CDC42 in the CRC SW620 cell line using gene expression analysis. Our results establish that several cancer-related signaling pathways, including cell migration and cell proliferation, are regulated by CDC42. This transcriptional signature was validated in two large cohorts of CRC patients and its clinical relevance was also studied. We demonstrate that three CDC42-regulated genes offered a better prognostic value when combined with CDC42 compared to CDC42 alone. In particular, the concordant overexpression of CDC42 and silencing of the putative tumor suppressor gene CACNA2D2 dramatically improved the prognostic value. The CACNA2D2/CDC42 prognostic classifier was further validated in a third CRC cohort as well as in vitro and in vivo CRC models. Altogether, we show that CDC42 has an active oncogenic role in CRC via the transcriptional regulation of multiple cancer-related pathways and that CDC42-mediated silencing of CACNA2D2 is clinically relevant. Our results further support the use of CDC42 specific inhibitors for the treatment of the most aggressive types of CRC

    Evolution of leaf-form in land plants linked to atmospheric CO2 decline in the Late Palaeozoic era

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    The widespread appearance of megaphyll leaves, with their branched veins and planate form, did not occur until the close of the Devonian period at about 360 Myr ago. This happened about 40 Myr after simple leafless vascular plants first colonized the land in the Late Silurian/Early Devonian, but the reason for the slow emergence of this common feature of present-day plants is presently unresolved. Here we show, in a series of quantitative analyses using fossil leaf characters and biophysical principles, that the delay was causally linked with a 90% drop in atmospheric pCO2 during the Late Palaeozoic era. In contrast to simulations for a typical Early Devonian land plant, possessing few stomata on leafless stems, those for a planate leaf with the same stomatal characteristics indicate that it would have suffered lethal overheating, because of greater interception of solar energy and low transpiration. When planate leaves first appeared in the Late Devonian and subsequently diversified in the Carboniferous period, they possessed substantially higher stomatal densities. This observation is consistent with the effects of the pCO2 on stomatal development and suggests that the evolution of planate leaves could only have occurred after an increase in stomatal density, allowing higher transpiration rates that were sufficient to maintain cool and viable leaf temperatures

    Effectiveness of individualized inhaler technique training on low adherence (LowAd) in ambulatory patients with COPD and asthma

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    © 2022. This document is made available under the CC-BY 4.0 license http://creativecommons.org/licenses/by /4.0/ This document is the published version of a published work that appeared in final form in npj primary care respiratory medicineTo analyze whether there is improvement in adherence to inhaled treatment in patients with COPD and asthma after an educational intervention based on the teach-to-goal method. This is a prospective, non-randomized, single-group study, with intervention and before-after evaluation. The study population included 120 patients (67 females and 53 males) diagnosed with asthma (70.8%) and COPD (29.1%). The level of adherence (low and optimal) and the noncompliance behavior pattern (erratic, deliberate and unwitting) were determined by the Test of the adherence to Inhalers (TAI). This questionnaire allows you to determine the level of adherence and the types of noncompliance. Low Adherence (LowAd) was defined as a score less than 49 points. All patients received individualized educational inhaler technique intervention (IEITI). Before the IEITI, 67.5% of the patients had LowAd. Following IEITI, on week 24, LowAd was 55% (p = 0.024). Each patient can present one or more types of noncompliance. The most frequent type was forgetting to use the inhaler (erratic), 65.8%. The other types were deliberate: 43.3%, and unwitting: 57.5%. All of them had decreased on the final visit: 51.7% (p = 0.009), 25.8% (p = 0.002), 39.2% (p = 0.002). There were no significant differences in adherence between asthma and COPD patients at the start of the study. The only predicting factor of LowAd was the female gender. An individualized educational intervention, in ambulatory patients with COPD and asthma, in real-world clinical practice conditions, improves adherence to the inhaled treatment

    Multi-level evidence of an allelic hierarchy of USH2A variants in hearing, auditory processing and speech/language outcomes.

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    Language development builds upon a complex network of interacting subservient systems. It therefore follows that variations in, and subclinical disruptions of, these systems may have secondary effects on emergent language. In this paper, we consider the relationship between genetic variants, hearing, auditory processing and language development. We employ whole genome sequencing in a discovery family to target association and gene x environment interaction analyses in two large population cohorts; the Avon Longitudinal Study of Parents and Children (ALSPAC) and UK10K. These investigations indicate that USH2A variants are associated with altered low-frequency sound perception which, in turn, increases the risk of developmental language disorder. We further show that Ush2a heterozygote mice have low-level hearing impairments, persistent higher-order acoustic processing deficits and altered vocalizations. These findings provide new insights into the complexity of genetic mechanisms serving language development and disorders and the relationships between developmental auditory and neural systems

    Bats Use Magnetite to Detect the Earth's Magnetic Field

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    While the role of magnetic cues for compass orientation has been confirmed in numerous animals, the mechanism of detection is still debated. Two hypotheses have been proposed, one based on a light dependent mechanism, apparently used by birds and another based on a “compass organelle” containing the iron oxide particles magnetite (Fe3O4). Bats have recently been shown to use magnetic cues for compass orientation but the method by which they detect the Earth's magnetic field remains unknown. Here we use the classic “Kalmijn-Blakemore” pulse re-magnetization experiment, whereby the polarity of cellular magnetite is reversed. The results demonstrate that the big brown bat Eptesicus fuscus uses single domain magnetite to detect the Earths magnetic field and the response indicates a polarity based receptor. Polarity detection is a prerequisite for the use of magnetite as a compass and suggests that big brown bats use magnetite to detect the magnetic field as a compass. Our results indicate the possibility that sensory cells in bats contain freely rotating magnetite particles, which appears not to be the case in birds. It is crucial that the ultrastructure of the magnetite containing magnetoreceptors is described for our understanding of magnetoreception in animals

    Improved selectivity and cytotoxic effects of irinotecan via liposomal delivery: A comparative study on Hs68 and HeLa cells

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    Irinotecan (CPT-11) is an effective chemotherapeutic agent widely used to treat different cancers. Otherwise, the liposomal delivery of anti-tumor agents has been shown to be a promising strategy. The aim of this study has been to analyze the effect of liposomal CPT-11 (CPT-11lip) on two human cell lines (Hs68 and HeLa) to establish the suitability of this CPT-11 nanocarrier. We have demonstrated the highest uptake of CPT-11lip in comparison with that of CPT-11sol, in lactate buffer, and that CPT-11lip was internalized in the cells through an endocytic process whereas CPT-11sol does so by passive diffusion. CPT-11lip was not cytotoxic to normal fibroblast Hs68 cells, but induced a massive apoptosis accompanied by cell senescence in HeLa cells. CPT-11lip treatment modified the morphology of HeLa cells, induced different cell cycle alterations and accumulated into lysosomes in both cell lines. In particular, CPT-11lip treatment showed that surviving HeLa cells remained in a state of senescence whereas only a temporal growth arrest was induced in Hs68 cells. Results of RT-PCR indicated that the different responses in Hs68 (survival) and HeLa cells (apoptotic death), seemed to be induced by a p53- and p53- independent mechanism, respectively. An analysis of DNA damage also determined that released CPT-11 from liposomes was able to reach the nucleus and exert a genotoxic effect in both cell lines, which was repaired in Hs68 but not in HeLa cells. All results indicate that phospholipid-cholesterol liposomes possess optimum properties for CPT-11 delivery, being biocompatible and selectively cytotoxic against HeLa tumorigenic cells.
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