50 research outputs found

    PETROLOGICAL CONSTRAINTS ON THE ORIGIN OF PYROXENITE DYKES IN THE LITHOSPHERIC MANTLE OF THE CHESHMEH-BID OPHIOLITIC MASSIF, SOUTHERN IRAN

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    The Cheshmeh-Bid ophiolitic massif in the Khajeh-Jamali district (Southern Iran) is dominated by harzburgite-dunite tectonites locally intruded by orthopy-roxenite dikes. These latter are composed of dominant coarse orthopyroxene with minor olivine, Cr-spinel, clinopyroxene and amphibole. Estimated equilibrium temperatures for Mg-hornblende and edenitic amphibole reveal a late stage magmatic origin.The Cheshmeh-Bid orthopyroxenites are characterized by very low Al2O3, CaO, Na2O and TiO2 abundances coupled to relatively high MgO and SiO2contents. They display U-shaped REE patterns, selective LILE enrichment and positive Pb and Sr anomalies. The host harzburgites are highly refractory mantle residues resulting from fluid-assisted melting. Field observations and mineral assemblages suggest that the pyroxenites formed by melt injection along fractures within rather cold ambient harzburgites and chromitites at moderate pressure (P > 1 GPa). Based on bulk-rock compositions and mineral chemistry, we infer that the Cheshmeh-Bid orthopyroxenites originated from the intrusion and crystallization of hydrous Si-rich, low-Ca melts with a boninite signature in a supra-subduction environment. Fine-grained neoblastic domains developed in the pyroxenites in response to subsolidus ductile deformation and recrystallization, which were most likely related to the exhumation of the Cheshmeh-Bid ophiolite massif

    Microbial community of the deep-sea brine Lake <em>Kryos </em>seawater-brine interface is active below the chaotropicity limit of life as revealed by recovery of mRNA

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    Within the complex of deep, hypersaline anoxic lakes (DHALs) of the Mediterranean Ridge we identified a new, unexplored DHAL and named it "Lake Kryos" after a nearby depression. This lake is filled with MgCl2-rich, athalassohaline brine (salinity >470 practical salinity units), presumably formed by the dissolution of Messinian bischofite. Compared to the DHAL Discovery, it contains elevated concentrations of kosmotropic sodium and sulfate ions, which are capable of reducing the net chaotropicily of MgCl2-rich solutions. The brine of Lake Kryos may therefore be biologically permissive at MgCl2 concentrations previously considered incompatible with life. We characterized the microbiology of the seawater-Kryos brine interface and managed to recover mRNA from the 2.27-3.03 M MgCl2 layer (equivalent to 0.747-0.631 water-activity) thereby expanding the established chaotropicity window-for-life. The primary bacterial taxa present there were KB1 candidate division and DHAL-specific group of organisms, distantly related to Desulfohalobium. Two euryarchaeal candidate divisions MSBL1 and HC1, detected in minority in the overlaying layers, accounted for more than 85% of the rRNA-containing archaeal clones analyzed in 2.27-3.03 M MgCl2 layer. These findings shed light on the plausibility of life in highly chaotropic environments, geochemical windows for microbial extremophiles, and have implications for habitability elsewhere in the Solar System

    Codesigning a systemic discharge intervention for inpatient mental health settings (MINDS): a protocol for integrating realist evaluation and an engineering-based systems approach

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    © 2023 The Author(s). Published by BMJ. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/Introduction: Transition following discharge from mental health hospital is high risk in terms of relapse, readmission and suicide. Discharge planning supports transition and reduces risk. It is a complex activity involving interacting systemic elements. The codesigning a systemic discharge intervention for inpatient mental health settings (MINDS) study aims to improve the process for people being discharged, their carers/supporters and staff who work in mental health services, by understanding, co-designing and evaluating implementation of a systemic approach to discharge planning. Methods and analysis: The MINDS study integrates realist research and an engineering-informed systems approach across three stages. Stage 1 applies realist review and evaluation using a systems approach to develop programme theories of discharge planning. Stage 2 uses an Engineering Better Care framework to codesign a novel systemic discharge intervention, which will be subjected to process and economic evaluation in stage 3. The programme theories and resulting care planning approach will be refined throughout the study ready for a future clinical trial. MINDS is co-led by an expert by experience, with researchers with lived experience co-leading each stage. Ethics and dissemination: MINDS stage 1 has received ethical approval from Yorkshire & The Humber—Bradford Leeds (Research Ethics Committee (22/YH/0122). Findings from MINDS will be disseminated via high-impact journal publications and conference presentations, including those with service user and mental health professional audiences. We will establish routes to engage with public and service user communities and National Health Service professionals including blogs, podcasts and short videos. Trial registration number: MINDS is funded by the National Institute of Health Research (NIHR 133013) https://fundingawards.nihr.ac.uk/award/NIHR133013. The realist review protocol is registered on PROSPERO. PROSPERO registration number: CRD42021293255.Peer reviewe

    A graph-theoretical approach in brain functional networks. Possible implications in EEG studies

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    Abstract\ud \ud \ud \ud Background\ud \ud Recently, it was realized that the functional connectivity networks estimated from actual brain-imaging technologies (MEG, fMRI and EEG) can be analyzed by means of the graph theory, that is a mathematical representation of a network, which is essentially reduced to nodes and connections between them.\ud \ud \ud \ud Methods\ud \ud We used high-resolution EEG technology to enhance the poor spatial information of the EEG activity on the scalp and it gives a measure of the electrical activity on the cortical surface. Afterwards, we used the Directed Transfer Function (DTF) that is a multivariate spectral measure for the estimation of the directional influences between any given pair of channels in a multivariate dataset. Finally, a graph theoretical approach was used to model the brain networks as graphs. These methods were used to analyze the structure of cortical connectivity during the attempt to move a paralyzed limb in a group (N=5) of spinal cord injured patients and during the movement execution in a group (N=5) of healthy subjects.\ud \ud \ud \ud Results\ud \ud Analysis performed on the cortical networks estimated from the group of normal and SCI patients revealed that both groups present few nodes with a high out-degree value (i.e. outgoing links). This property is valid in the networks estimated for all the frequency bands investigated. In particular, cingulate motor areas (CMAs) ROIs act as ‘‘hubs’’ for the outïŹ‚ow of information in both groups, SCI and healthy. Results also suggest that spinal cord injuries affect the functional architecture of the cortical network sub-serving the volition of motor acts mainly in its local feature property.\ud In particular, a higher local efficiency El can be observed in the SCI patients for three frequency bands, theta (3-6 Hz), alpha (7-12 Hz) and beta (13-29 Hz).\ud By taking into account all the possible pathways between different ROI couples, we were able to separate clearly the network properties of the SCI group from the CTRL group. In particular, we report a sort of compensatory mechanism in the SCI patients for the Theta (3-6 Hz) frequency band, indicating a higher level of “activation” Ω within the cortical network during the motor task. The activation index is directly related to diffusion, a type of dynamics that underlies several biological systems including possible spreading of neuronal activation across several cortical regions.\ud \ud \ud \ud Conclusions\ud \ud The present study aims at demonstrating the possible applications of graph theoretical approaches in the analyses of brain functional connectivity from EEG signals. In particular, the methodological aspects of the i) cortical activity from scalp EEG signals, ii) functional connectivity estimations iii) graph theoretical indexes are emphasized in the present paper to show their impact in a real application.This study was performed with support of the European Union, through the COST program NEUROMATH (BM0601). This paper only reflects the authors’ views and funding agency is not liable for any use that may be made of the information contained herein.This study was performed with support of the European Union, through the COST program NEUROMATH (BM0601). This paper only reflects the authors’ views and funding agency is not liable for any use that may be made of the information contained herein.This article has been published as part of Nonlinear Biomedical Physics Volume 4 Supplement 1, 2010: Consciousness and its Measures: Joint Workshop for COST Actions Neuromath and Consciousness. The full contents of the supplement are available online at http://www.nonlinearbiomedphys.com/supplements/4/S1.This article has been published as part of Nonlinear Biomedical Physics Volume 4 Supplement 1, 2010: Consciousness and its Measures: Joint Workshop for COST Actions Neuromath and Consciousness. The full contents of the supplement are available online at http://www.nonlinearbiomedphys.com/supplements/4/S1

    Some sphere theorems in linear potential theory

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    In this paper we analyze the capacitary potential due to a charged body in order to deduce sharp analytic and geometric inequalities, whose equality cases are saturated by domains with spherical symmetry. In particular, for a regular bounded domain Ω ⊂ Rn, n ≄ 3, we prove that if the mean curvature H of the boundary obeys the condition (Formula Presented) then Ω is a round ball.SCOPUS: ar.jDecretOANoAutActifinfo:eu-repo/semantics/publishe

    Extremely low doses of arsenic affect in vitro pollen germination

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    Introduction: This study deals with the effects of extremely low doses or high dilutions of pharmacological compounds on in vitro pollen germination of kiwifruit (Actinidia deliciosa). Material and Methods: The biological efficacy of As2O3 at the 5th and 45th decimal dilution/succussion level (As 5x and As 45x) was tested on pollen previously stressed with As2O3 150 or 200 \u3bcM. The outcome variable was the pollen germination rate, as detected blind after 3 h 30 min by an Axioplan microscope. Results: A directionally consistent recovery of germination percentage was observed in both As 5x and As 45x after stressing with As2O3 150 \u3bcM. When pollen was stressed with As2O3 200 \u3bcM only as 45x induced a general and significant germination increase. Conclusions: Our results suggest that both treatments might partially remove the inhibitory effect caused by the stressor. Similar effects were observed on the same model using weak extremely low frequency magnetic fields (ELF-MFs) mediated through water. Although preliminary, the findings seem to indicate the in vitro pollen performance as adequate to study the effects of physicochemical subthreshold stimuli (extremely low doses or high dilutions of pharmacological compounds, weak ELF-MFs), mediated through water

    Improving flight simulation performance by using tDCS stimulation

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    The aim of this work is to demonstrate if the transcranial direct current stimulation (tDCS) should be useful to improve the performance of subjects while they are engaged in a flight simulation and, at the same time, in other secondary tasks. The evaluation of the flight performance is done by analyzing the pitch and bank angles respect to an ideal flight path that the subject learnt during the training sessions, while the tasks of alert and vigilance (TAV), the secondary tasks, are estimated by analyzing the reaction times and the error rates. Before the experiments the subjects receive a tDC stimulation, but they do not know about the possibility of a \u2018fake\u2019 stimulation (Sham condition), during which the tDCS device automatically turns off after few seconds. By comparing the performances of the two experimental conditions, with and without the tDCS, it is possible to find out if this kind of stimulation could help the enhancement of the performance before real operational missions. Also, the results are compared to the NASA-TLX scores for checking if the subjective workload evaluations have any relations with the performance levels of the two experimental conditions

    Measuring neurophysiological signals in aircraft pilots and car drivers for the assessment of mental workload, fatigue and drowsiness

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    This paper reviews published papers related to neurophysiological measurements (electroencephalography: EEG, electrooculography EOG; heart rate: HR) in pilots/drivers during their driving tasks. The aim is to summarise the main neurophysiological findings related to the measurements of pilot/driver's brain activity during drive performance and how particular aspects of this brain activity could be connected with the important concepts of "mental workload", "mental fatigue" or "situational awareness". Review of the literature suggests that exists a coherent sequence of changes for EEG, EOG and HR variables during the transition from normal drive, high mental workload and eventually mental fatigue and drowsiness. In particular, increased EEG power in theta band and a decrease in alpha band occurred in high mental workload. Successively, increased EEG power in theta as well as delta and alpha bands characterise the transition between mental workload and mental fatigue. Drowsiness is also characterised by increased blink rate and decreased HR values. The detection of such mental states is actually performed "offline" with accuracy around 90% but not online. A discussion on the possible future applications of findings provided by these neurophysiological measurements in order to improve the safety of the vehicles will be also presented
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