552 research outputs found
Assessing behavioural changes in ALS: cross-validation of ALS-specific measures
Objective: The Beaumont Behavioural Inventory (BBI) is a behavioural proxy report for the assessment of behavioural changes in ALS. This tool has been validated against the FrSBe, a non-ALS specific behavioural assessment, and further comparison of the BBI against a disease-specific tool was considered. This study cross-validates the BBI against the ALS-FTD-Q.
Methods: 60 ALS patients, 8% also meeting criteria for FTD, were recruited. All patients were evaluated using the BBI and the ALS-FTD-Q, completed by a carer. Correlational analysis was performed to assess construct validity. Precision, sensitivity, specificity and overall accuracy of the BBI, when compared to the ALS-FTD-Q, were obtained.
Results: The mean score of the whole sample on the BBI was 11.45±13.06. ALS-FTD patients scored significantly higher than non-demented ALS patients (31.6±14.64, 9.62±11.38; p<.0001). A significant large positive correlation between the BBI and the ALS-FTD-Q was observed (r=.807, p<.0001), and no significant correlations between the BBI and other clinical/demographic characteristics, indicating good convergent and discriminant validity, respectively. 72% of overall concordance was observed. Precision, sensitivity and specificity for the classification of severely impaired patients were adequate. However, lower concordance in the classification of mild behavioural changes was observed, with higher sensitivity using the BBI, most likely secondary to BBI items which endorsed behavioural aspects not measured by the ALS-FTD-Q.
Discussion: Good construct validity has been further confirmed when the BBI is compared to an ALS-specific tool. Furthermore, the BBI is a more comprehensive behavioural assessment for ALS, as it measures the whole behavioural spectrum in this condition
First reported detection of the mobile colistin resistance genes, mcr-8 and mcr-9, in the Irish environment
The emergence and dissemination of mobile colistin resistance (mcr) genes across the globe poses a significant threat to public health, as colistin remains one of the last line treatment options for multi-drug resistant infections. Environmental samples (157 water and 157 wastewater) were collected in Ireland between 2018 and 2020. Samples collected were assessed for the presence of antimicrobial resistant bacteria using Brilliance ESBL, Brilliance CRE, mSuperCARBA and McConkey agar containing a ciprofloxacin disc. All water and integrated constructed wetland influent and effluent samples were filtered and enriched in buffered peptone water prior to culture, while wastewater samples were cultured directly. Isolates collected were identified via MALDI-TOF, were tested for susceptibility to 16 antimicrobials, including colistin, and subsequently underwent whole genome sequencing. Overall, eight mcr positive Enterobacterales (one mcr-8 and seven mcr-9) were recovered from six samples (freshwater (n = 2), healthcare facility wastewater (n = 2), wastewater treatment plant influent (n = 1) and integrated constructed wetland influent (piggery farm waste) (n = 1)). While the mcr-8 positive K. pneumoniae displayed resistance to colistin, all seven mcr-9 harbouring Enterobacterales remained susceptible. All isolates demonstrated multi-drug resistance and through whole genome sequencing analysis, were found to harbour a wide variety of antimicrobial resistance genes i.e., 30 ± 4.1 (10-61), including the carbapenemases, blaOXA-48 (n = 2) and blaNDM-1 (n = 1), which were harboured by three of the isolates. The mcr genes were located on IncHI2, IncFIIK and IncI1-like plasmids. The findings of this study highlight potential sources and reservoirs of mcr genes in the environment and illustrate the need for further research to gain a better understanding of the role the environment plays in the persistence and dissemination of antimicrobial resistance
Choroidalyzer: An open-source, end-to-end pipeline for choroidal analysis in optical coherence tomography
Purpose: To develop Choroidalyzer, an open-source, end-to-end pipeline for
segmenting the choroid region, vessels, and fovea, and deriving choroidal
thickness, area, and vascular index.
Methods: We used 5,600 OCT B-scans (233 subjects, 6 systemic disease cohorts,
3 device types, 2 manufacturers). To generate region and vessel ground-truths,
we used state-of-the-art automatic methods following manual correction of
inaccurate segmentations, with foveal positions manually annotated. We trained
a U-Net deep-learning model to detect the region, vessels, and fovea to
calculate choroid thickness, area, and vascular index in a fovea-centred region
of interest. We analysed segmentation agreement (AUC, Dice) and choroid metrics
agreement (Pearson, Spearman, mean absolute error (MAE)) in internal and
external test sets. We compared Choroidalyzer to two manual graders on a small
subset of external test images and examined cases of high error.
Results: Choroidalyzer took 0.299 seconds per image on a standard laptop and
achieved excellent region (Dice: internal 0.9789, external 0.9749), very good
vessel segmentation performance (Dice: internal 0.8817, external 0.8703) and
excellent fovea location prediction (MAE: internal 3.9 pixels, external 3.4
pixels). For thickness, area, and vascular index, Pearson correlations were
0.9754, 0.9815, and 0.8285 (internal) / 0.9831, 0.9779, 0.7948 (external),
respectively (all p<0.0001). Choroidalyzer's agreement with graders was
comparable to the inter-grader agreement across all metrics.
Conclusions: Choroidalyzer is an open-source, end-to-end pipeline that
accurately segments the choroid and reliably extracts thickness, area, and
vascular index. Especially choroidal vessel segmentation is a difficult and
subjective task, and fully-automatic methods like Choroidalyzer could provide
objectivity and standardisation
Soil methane sink capacity response to a long-term wildfire chronosequence in Northern Sweden
Boreal forests occupy nearly one fifth of the terrestrial land surface and are recognised as globally important regulators of carbon (C) cycling and greenhouse gas emissions. Carbon sequestration processes in these forests include assimilation of CO2 into biomass and subsequently into soil organic matter, and soil microbial oxidation of methane (CH4). In this study we explored how ecosystem retrogression, which drives vegetation change, regulates the important process of soil CH4 oxidation in boreal forests. We measured soil CH4 oxidation processes on a group of 30 forested islands in northern Sweden differing greatly in fire history, and collectively representing a retrogressive chronosequence, spanning 5000 years. Across these islands the build-up of soil organic matter was observed to increase with time since fire disturbance, with a significant correlation between greater humus depth and increased net soil CH4 oxidation rates. We suggest that this increase in net CH4 oxidation rates, in the absence of disturbance, results as deeper humus stores accumulate and provide niches for methanotrophs to thrive. By using this gradient we have discovered important regulatory controls on the stability of soil CH4 oxidation processes that could not have not been explored through shorter-term experiments. Our findings indicate that in the absence of human interventions such as fire suppression, and with increased wildfire frequency, the globally important boreal CH4 sink could be diminished
Recommended from our members
Clustering of neuropsychiatric disease in first-degree and second-degree relatives of patients with amyotrophic lateral sclerosis
Importance
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative condition primarily involving the motor system. There is increasing epidemiologic evidence of an association between ALS and a wider spectrum of neurodegenerative and neuropsychiatric disorders among family members, including schizophrenia and psychotic illness and suicidal behavior.
Objective
To examine the frequency and range of neuropsychiatric conditions that occur within individual first-degree and second-degree relatives of patients with ALS.
Design, Setting, and Participants
In this population-based, case-control family aggregation study, all 202 patients included in the Irish ALS Register between January 1, 2012, and January 31, 2014, with definite, probable, or possible ALS as defined by El Escorial criteria were invited to participate. A total of 75 patients were unable or refused to participate and were excluded; the remaining 127 patients with incident ALS were genotyped for the C9orf72 repeat expansion and 132 age- and sex-matched controls were included in the study.
Main Outcome and Measures
The prevalence of defined neuropsychiatric disease in first-degree and second-degree relatives of patients with ALS and matched controls was determined.
Results
Mean (SD) age at diagnosis of the 127 patients in the study (58 women and 69 men) was 64.2 (10.7) years. Data from 2116 relatives of patients with ALS were reported, including 924 first-degree relatives, 1128 second-degree relatives, and 64 third-degree relatives. Data from controls were reported from 829 first-degree and 1310 second-degree relatives. A total of 77 patients with ALS (61.4%) and 51 control participants (38.6%) reported at least 1 first-degree or second-degree relative with a history of schizophrenia, psychosis, suicide, depression, alcoholism, or autism (relative risk [RR], 1.50; 95% CI, 1.08-2.17; Pâ=â.02). Cluster analysis suggested the following 2 subgroups based on the number of family members with a neuropsychiatric condition: expected (0-2) and high (â„3). Within the high subgroup, ALS kindreds presented a significantly higher rate of psychiatric illness than did controls (28 of 39 [71.8%]; mean [SD] number of siblings, 4.29 [1.41]; Pâ=â.001). A strong family history of schizophrenia (RR, 3.40; 95% CI, 1.27-9.30; Pâ=â.02), suicide (RR, 3.30; 95% CI, 1.07-10.05; Pâ=â.04), autism (RR, 10.10; 95% CI, 1.30-78.80; Pâ=â.03), and alcoholism (RR, 1.48; 95% CI, 1.01-2.17; Pâ=â.045) was reported in ALS kindreds. A total of 5 of 29 probands (17.2%) with a strong family history of neuropsychiatric conditions (â„3 first-degree or second-degree relatives) carried the C9orf72 repeat expansion.
Conclusions and Relevance
Neuropsychiatric symptoms in addition to schizophrenia, including obsessive-compulsive disorder, autism, and alcoholism, occur more frequently in ALS kindreds than in controls. The presence of the C9orf72 repeat expansion does not fully account for this finding, suggesting the presence of additional pleiotropic genes associated with both ALS and neuropsychiatric disease in the Irish population
Increased plasma thioredoxin levels in patients with sepsis: positive association with macrophage migration inhibitory factor.
PURPOSE: To establish the relationship between plasma levels of thioredoxin (Trx) and macrophage migration inhibitory factor (MIF) in systemic inflammatory stress syndrome (SIRS)/sepsis. METHODS: Enzyme-linked immunosorbent assay measurements of Trx, MIF, IL-6, -8, and -10 and enzyme-linked fluorescent assay determination of procalcitonin (PCT) in plasma from patients with SIRS/sepsis, neutropenic sepsis, healthy volunteers and pre-oesophagectomy patients. RESULTS: Thioredoxin was significantly higher in SIRS/sepsis patients [101.3 ng ml(â1), interquartile range (IQR) 68.7â155.6, n = 32] compared with that in healthy controls (49.5 ng ml(â1), IQR 31.4â71.1, P < 0.001, n = 17) or pre-oesophagectomy patients (40.5 ng ml(â1), IQR 36.9â63.2, P < 0.01, n = 7), but was not raised in neutropenics (n = 5). MIF levels were also significantly higher in SIRS/sepsis patients (12.1 ng ml(â1), IQR 9.5â15.5, n = 35), but not in the neutropenic group, when compared with healthy controls (9.3 ng ml(â1), IQR 7.3â10.7, P < 0.01, n = 20). Trx levels correlated, positively, with MIF levels and APACHE II scores. Plasma levels of IL-6, -8 and -10 and PCT increased significantly in patients with SIRS/sepsis (P < 0.001) and with neutropenic sepsis, but did not correlate with Trx or MIF levels. CONCLUSION: Plasma levels of Trx, MIF, IL-6, -8, -10 and PCT were raised in patients with SIRS/sepsis. Comparisons between mediators suggest a unique correlation of Trx with MIF. Moreover, Trx and MIF differed from cytokines and PCT in that levels were significantly lower in patients with neutropenia compared with the main SIRS/sepsis group. By contrast, IL-8 and PCT levels were significantly greater in the neutropenic patient group. The link between MIF and Trx highlighted in this study has implications for future investigations into the pathogenesis of SIRS/sepsis
Dynamic Blood-Brain Barrier Regulation in Mild Traumatic Brain Injury
Whereas the diagnosis of moderate and severe traumatic brain injury (TBI) is readily visible on current medical imaging paradigms (magnetic resonance imaging [MRI] and computed tomography [CT] scanning), a far greater challenge is associated with the diagnosis and subsequent management of mild TBI (mTBI), especially concussion which, by definition, is characterized by a normal CT. To investigate whether the integrity of the blood-brain barrier (BBB) is altered in a high-risk population for concussions, we studied professional mixed martial arts (MMA) fighters and adolescent rugby players. Additionally, we performed the linear regression between the BBB disruption defined by increased gadolinium contrast extravasation on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) on MRI and multiple biomechanical parameters indicating the severity of impacts recorded using instrumented mouthguards in professional MMA fighters. MMA fighters were examined pre-fight for a baseline and again within 120 h post-competitive fight, whereas rugby players were examined pre-season and again post-season or post-match in a subset of cases. DCE-MRI, serological analysis of BBB biomarkers, and an analysis of instrumented mouthguard data, was performed. Here, we provide pilot data that demonstrate disruption of the BBB in both professional MMA fighters and rugby players, dependent on the level of exposure. Our data suggest that biomechanical forces in professional MMA and adolescent rugby can lead to BBB disruption. These changes on imaging may serve as a biomarker of exposure of the brain to repetitive subconcussive forces and mTBI
Ten simple rules for making training materials FAIR
Author summary: Everything we do today is becoming more and more reliant on the use of computers. The field of biology is no exception; but most biologists receive little or no formal preparation for the increasingly computational aspects of their discipline. In consequence, informal training courses are often needed to plug the gaps; and the demand for such training is growing worldwide. To meet this demand, some training programs are being expanded, and new ones are being developed. Key to both scenarios is the creation of new course materials. Rather than starting from scratch, however, itâs sometimes possible to repurpose materials that already exist. Yet finding suitable materials online can be difficult: Theyâre often widely scattered across the internet or hidden in their home institutions, with no systematic way to find them. This is a common problem for all digital objects. The scientific community has attempted to address this issue by developing a set of rules (which have been called the Findable, Accessible, Interoperable and Reusable [FAIR] principles) to make such objects more findable and reusable. Here, we show how to apply these rules to help make training materials easier to find, (re)use, and adapt, for the benefit of all
Quantum confinement-induced semimetal-to-semiconductor evolution in large-area ultra-thin PtSe2 films grown at 400 °C
In this work, we present a comprehensive theoretical and experimental study of quantum confinement in layered platinum diselenide (PtSe2) films as a function of film thickness. Our electrical measurements, in combination with density functional theory calculations, show distinct layer-dependent semimetal-to-semiconductor evolution in PtSe2 films, and highlight the importance of including van der Waals interactions, Greenâs function calibration, and screened Coulomb interactions in the determination of the thickness-dependent PtSe2 energy gap. Large-area PtSe2 films of varying thickness (2.5â6.5ânm) were formed at 400â°C by thermally assisted conversion of ultra-thin platinum films on Si/SiO2 substrates. The PtSe2 films exhibit p-type semiconducting behavior with hole mobility values up to 13âcm2/V·s. Metal-oxide-semiconductor field-effect transistors have been fabricated using the grown PtSe2 films and a gate field-controlled switching performance with an ION/IOFF ratio of >230 has been measured at room temperature for a 2.5â3ânm PtSe2 film, while the ratio drops to <2 for 5â6.5ânm-thick PtSe2 films, consistent with a semiconducting-to-semimetallic transition with increasing PtSe2 film thickness. These experimental observations indicate that the low-temperature growth of semimetallic or semiconducting PtSe2 could be integrated into the back-end-of-line of a silicon complementary metal-oxide-semiconductor process
Growth and retreat of the last BritishâIrish Ice Sheet, 31 000 to 15 000 years ago: the BRITICE-CHRONO reconstruction
The BRITICE-CHRONO consortium of researchers undertook a dating programme to constrain the timing of advance, maximum extent and retreat of the BritishâIrish Ice Sheet between 31â000 and 15â000âyears before present. The dating campaign across Ireland and Britain and their continental shelves, and across the North Sea included 1500âdays of field investigation yielding 18â000âkm of marine geophysical data, 377 cores of sea floor sediments, and geomorphological and stratigraphical information at 121 sites on land; generating 690 new geochronometric ages. These findings are reported in 28 publications including synthesis into eight transect reconstructions. Here we build ice sheet-wide reconstructions consistent with these findings and using retreat patterns and dates for the inter-transect areas. Two reconstructions are presented, a wholly empirical version and a version that combines modelling with the new empirical evidence. Palaeoglaciological maps of ice extent, thickness, velocity, and flow geometry at thousand-year timesteps are presented. The maximum ice volume of 1.8âm sea level equivalent occurred at 23âka. A larger extent than previously defined is found and widespread advance of ice to the continental shelf break is confirmed during the last glacial. Asynchrony occurred in the timing of maximum extent and onset of retreat, ranging from 30 to 22âka. The tipping point of deglaciation at 22âka was triggered by ice stream retreat and saddle collapses. Analysis of retreat rates leads us to accept our hypothesis that the marine-influenced sectors collapsed rapidly. First order controls on ice-sheet demise were glacio-isostatic loading triggering retreat of marine sectors, aided by glaciological instabilities and then climate warming finished off the smaller, terrestrial ice sheet. Overprinted on this signal were second order controls arising from variations in trough topographies and with sector-scale ice geometric readjustments arising from dispositions in the geography of the landscape. These second order controls produced a stepped deglaciation. The retreat of the BritishâIrish Ice Sheet is now the worldâs most well-constrained and a valuable data-rich environment for improving ice-sheet modelling.publishedVersio
- âŠ