355 research outputs found
The relationship between the location of western mackerel spawning, larval drift and recruit distributions: A modelling study
Summary: Mackerel spawning distributions have changed over the last 20 years. From 1977-1995
there has been a progressive westerly shift in the distribution of spawning in May/June
(peak spawning), with a resultant increase in the proportion of spawning west of the shelf
break. Also during this time period there has been a marked increase in the proportion of
spawning in the north of the spawning area. This shift occurred most obviously between the
surveys carried out in 1986 and 1989. At the same time it is shown that there has been a
northerly shift in the distribution of first winter juveniles. These observations are derived
from data collected on the ICES coordinated winter bottom trawl surveys.
This study used data on mackerel egg distributions during May, derived from the ICES
triennial mackerel egg surveys as input to the NORWECOM transport model, using real
weather fields. The outputs from the model indicated that most eggs and larvae could
expect to be transported south after spawning and that there had been no significant change
in this transport pattern during the period studied. The combination of more northerly
spawning and the prevailing transport pattern may explain, in part, the increase in the
recruit population in the northern nursery areas. It is concluded that passive transport can
explain the juvenile distribution in some areas, but that active migration must also play a
role in the area of the Celtic Sea.
The interactions between the modelled transport patterns and the real egg distribution data
are discussed with reference to these topics and to the potential survival of larvae in the
first weeks after hatching
Detection of diphtheria antitoxin by four different methods
ObjectiveTo investigate the reliability of the different methods used in Norway and Russia for detection of diphtheria antitoxin.MethodsOne hundred and twenty-two sera were selected among Russian serum samples previously collected for seroepidemiologic studies of diphtheria antitoxin. The sera were selected to cover the total antitoxin range and were analyzed by four different antidiphtheria toxin assays: an in vitro toxin neutralization test using Vero cells (in vitro NT), an in vivo neutralization test using rabbit skin inoculation (in vivo NT), an indirect enzyme immunoassay (EIA) and a passive hemagglutination assay (PHA). The results were expressed according to the international standard as: not protected (<0.01 IU/mL), relatively protected (0.01–0.1 IU/mL) or protected (≤0.1 IU/mL). The sensitivity, specificity and inter-rater agreement (K or Kw) of each method were related to the in vitro NT selected as the reference method.ResultsThe in vivo NT test corresponded very well with the in vitro NT in its ability to differentiate between protection/relative protection and no protection (sensitivity 97%, specificity 87% and K=0.84). The EIA test showed a high sensitivity (96%), but since many sera were categorized as protected rather than not protected, the specificity (30%) and inter-rater agreement (K=0.29) were low. The PHA test had a very high specificity (100%) but a low sensitivity (86%).ConclusionsThe agreement between the two neutralization tests was high. If none of the neutralization assays is routinely available, the PHA test can be used to predict the need for vaccination on an individual basis but should not be used for seroepidemiologic studies, since the protection rate for diphtheria would be falsely too low, due to the lower sensitivity. The indirect EIA test used in this study should not be used routinely
Trajectories and stability of self-reported short sleep duration from adolescence to adulthood
The trajectories and stability of self-reported sleep duration recorded at ages 13, 15, and 23 years on reported sleep duration at age 30 years among 1105 students (55% male) who participated in the Norwegian Longitudinal Health and Behaviour Study were examined. Questionnaire data were used to obtain demographic and sleep variables. Dichotomised short sleep duration was based on normative values and set as ≤8.5 h (age 13 years), ≤8 h (age 15 years) and ≤7 h (ages 23 and 30 years). Results indicated a significant overall reduction in total sleep duration (h per night) across age groups. Sleep duration (continuous) at age 15 and 23 years (whole group) was moderately but positively correlated with sleep duration at age 30 years (P < 0.01). When split by sex, at age 15 years, this association was present among females only (P < 0.01); however, at age 23 years, this association was present in both male and females (both P < 0.001). Categorical short sleep at age 23 years (whole group) was associated with short sleep at age 30 years (unadjusted odds ratio = 3.67, 95% confidence interval 2.36-5.69). Following sex stratification, this effect was significant for both males (unadjusted odds ratio = 3.77, 95% confidence interval: 2.22-6.42) and females (unadjusted odds ratio = 2.71, 95% confidence interval: 1.46-5.04). No associations were noted for categorical short sleep at ages 13 or 15 years, and subsequent short sleep at 30 years. Habitual short sleep duration during middle adulthood is not sustained from the time of early adolescence. Rather, these trends appear to be formed during early adulthood
Development and analytical performance of an automated screening method for cannabinoids on the Dimension clinical chemistry system
A fully automated, random access method for the determination of
cannabinoids (UTHC) was developed for the Dimension AR and XL clinical chemistry systems. The method utilizes Abuscreen ONLINE reagents and a multianalyte liquid calibrator containing 11-nor-Δ9-THC-9-carboxylic acid. Within-run and
total reproducibility, determined using NCCLS protocol EP5-
T2, was less than 0.6% and 1.6% CV, respectively, at all concentrations. Calibration stability was retained for at least 30 days. An extensive evaluation of non-structurally related drugs and various physiological substances indicated lack of interference in the method. No sample carry-over was observed following a
specimen containing 1886 ng/ml 11-nor-Δ9-THC-9-carboxylic
acid. A 99.1% agreement (N = 445 samples) was found between an EMIT based method on the aca discrete clinical analyser and the Dimension UTHC method
Texture analysis on diffusion tensor imaging: discriminating glioblastoma from single brain metastasis
BACKGROUND: Texture analysis has been done on several radiological modalities to stage, differentiate, and predict prognosis in many oncologic tumors. PURPOSE: To determine the diagnostic accuracy of discriminating glioblastoma (GBM) from single brain metastasis (MET) by assessing the heterogeneity of both the solid tumor and the peritumoral edema with magnetic resonance imaging (MRI) texture analysis (MRTA). MATERIAL AND METHODS: Preoperative MRI examinations done on a 3-T scanner of 43 patients were included: 22 GBM and 21 MET. MRTA was performed on diffusion tensor imaging (DTI) in a representative region of interest (ROI). The MRTA was assessed using a commercially available research software program (TexRAD) which applies a filtration histogram technique for characterizing tumor and peritumoral heterogeneity. The filtration step selectively filters and extracts texture features at different anatomical scales varying from 2 mm (fine) to 6 mm (coarse). Heterogeneity quantification was obtained by the statistical parameter entropy. A threshold value to differentiate GBM from MET with sensitivity and specificity was calculated by receiver operating characteristic (ROC) analysis. RESULTS: Quantifying the heterogeneity of the solid part of the tumor showed no significant difference between GBM and MET. However, the heterogeneity of the GBMs peritumoral edema was significantly higher than the edema surrounding MET, differentiating them with a sensitivity of 80% and specificity of 90%. CONCLUSION: Assessing the peritumoral heterogeneity can increase the radiological diagnostic accuracy when discriminating GBM and MET. This will facilitate the medical staging and optimize the planning for surgical resection of the tumor and postoperative management
Diagnostic performance of texture analysis on MRI in grading cerebral gliomas
Background and purpose: Grading of cerebral gliomas is important both in treatment decision and assessment of prognosis. The purpose of this study was to determine the diagnostic accuracy of grading cerebral gliomas by assessing the tumor heterogeneity using MRI texture analysis (MRTA). / Material and methods: 95 patients with gliomas were included, 27 low grade gliomas (LGG) all grade II and 68 high grade gliomas (HGG) (grade III = 34 and grade IV = 34). Preoperative MRI examinations were performed using a 3T scanner and MRTA was done on preoperative contrast-enhanced three-dimensional isotropic spoiled gradient echo images in a representative ROI. The MRTA was assessed using a commercially available research software program (TexRAD) that applies a filtration-histogram technique for characterizing tumor heterogeneity. Filtration step selectively filters and extracts texture features at different anatomical scales varying from 2 mm (fine features) to 6 mm (coarse features), the statistical parameter standard deviation (SD) was obtained. Receiver operating characteristics (ROC) was performed to assess sensitivity and specificity for differentiating between the different grades and calculating a threshold value to quantify the heterogeneity. / Results: LGG and HGG was best discriminated using SD at fine texture scale, with a sensitivity and specificity of 93% and 81% (AUC 0.910, p < 0.0001). The diagnostic ability for MRTA to differentiate between the different sub-groups (grade II–IV) was slightly lower but still significant. / Conclusions: Measuring heterogeneity in gliomas to discriminate HGG from LGG and between different histological sub-types on already obtained images using MRTA can be a useful tool to augment the diagnostic accuracy in grading cerebral gliomas and potentially hasten treatment decision
Deep Learning-based Intraoperative MRI Reconstruction
Purpose: To evaluate the quality of deep learning reconstruction for
prospectively accelerated intraoperative magnetic resonance imaging (iMRI)
during resective brain tumor surgery.
Materials and Methods: Accelerated iMRI was performed during brain surgery
using dual surface coils positioned around the area of resection. A deep
learning (DL) model was trained on the fastMRI neuro dataset to mimic the data
from the iMRI protocol. Evaluation was performed on imaging material from 40
patients imaged between 01.11.2021 - 01.06.2023 that underwent iMRI during
tumor resection surgery. A comparative analysis was conducted between the
conventional compressed sense (CS) method and the trained DL reconstruction
method. Blinded evaluation of multiple image quality metrics was performed by
two working neuro-radiologists and a working neurosurgeon on a 1 to 5 Likert
scale (1=non diagnostic, 2=poor, 3=acceptable, 4=good, 5=excellent), and the
favored reconstruction variant.
Results: The DL reconstruction was strongly favored or favored over the CS
reconstruction for 33/40, 39/40, and 8/40 of cases for reader 1, 2, and 3,
respectively. Two of three readers consistently assigned higher ratings for the
DL reconstructions, and the DL reconstructions had a higher score than their
respective CS counterparts for 72%, 72%, and 14% of the cases for reader 1, 2,
and 3, respectively. Still, the DL reconstructions exhibited shortcomings such
as a striping artifact and reduced signal.
Conclusion: DL shows promise to allow for high-quality reconstructions of
intraoperative MRI with equal to or improved perceived spatial resolution,
signal-to-noise ratio, diagnostic confidence, diagnostic conspicuity, and
spatial resolution compared to compressed sense
Effects of large-scale heathland management on thermal regimes and predation on adders Vipera berus
Management prescriptions for species of conservation concern often focus on creating appropriate habitat conditions, but the spatial scales over which these actions are applied can potentially impact their success. In Northwestern Europe, preventing further loss of lowland heathland through successional changes often involves the mechanical removal of vegetation, creating large blocks of open homogenous habitat. We investigate the influence of this broad-scale habitat management on a heathland specialist, the adder Vipera berus. By deploying temperature loggers and Plasticine adder models in heathland areas with and without complex vegetation cover, we show that (1) cleared areas lack both the temperature variation adders need to thermoregulate effectively and suitable refuges from dangerously high summer temperatures, and (2) attacks by dogs and trampling by grazing livestock are significantly more frequent in cleared areas and closer to footpaths. Habitat management strategies that retain some structural complexity of vegetation within cleared areas, and diverting footpaths away from cleared areas and/or strategic placement of barrier hedging around these areas could potentially reduce the exposure of adders to high predation risk and thermal extremes
A prominent lack of IgG1-Fc fucosylation of platelet alloantibodies in pregnancy.
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This article is open access.Immunoglobulin G (IgG) formed during pregnancy against human platelet antigens (HPAs) of the fetus mediates fetal or neonatal alloimmune thrombocytopenia (FNAIT). Because antibody titer or isotype does not strictly correlate with disease severity, we investigated by mass spectrometry variations in the glycosylation at Asn297 in the IgG Fc because the composition of this glycan can be highly variable, affecting binding to phagocyte IgG-Fc receptors (FcγR). We found markedly decreased levels of core fucosylation of anti-HPA-1a-specific IgG1 from FNAIT patients (n = 48), but not in total serum IgG1. Antibodies with a low amount of fucose displayed higher binding affinity to FcγRIIIa and FcγRIIIb, but not to FcγRIIa, compared with antibodies with a high amount of Fc fucose. Consequently, these antibodies with a low amount of Fc fucose showed enhanced phagocytosis of platelets using FcγRIIIb(+) polymorphonuclear cells or FcγRIIIa(+) monocytes as effector cells, but not with FcγRIIIa(-) monocytes. In addition, the degree of anti-HPA-1a fucosylation correlated positively with the neonatal platelet counts in FNAIT, and negatively to the clinical disease severity. In contrast to the FNAIT patients, no changes in core fucosylation were observed for anti-HLA antibodies in refractory thrombocytopenia (post platelet transfusion), indicating that the level of fucosylation may be antigen dependent and/or related to the immune milieu defined by pregnancy.Sanquin/PPOC-09- 025
Landsteiner Foundation for Blood Transfusion/0721
info:eu-repo/grantAgreement/EC/FP7/27853
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